The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_descrip.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1991, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)kern_descrip.c      8.6 (Berkeley) 4/19/94
   35  */
   36 
   37 #include <sys/cdefs.h>
   38 __FBSDID("$FreeBSD: releng/9.0/sys/kern/kern_descrip.c 226407 2011-10-15 22:27:59Z rwatson $");
   39 
   40 #include "opt_capsicum.h"
   41 #include "opt_compat.h"
   42 #include "opt_ddb.h"
   43 #include "opt_ktrace.h"
   44 #include "opt_procdesc.h"
   45 
   46 #include <sys/param.h>
   47 #include <sys/systm.h>
   48 
   49 #include <sys/capability.h>
   50 #include <sys/conf.h>
   51 #include <sys/domain.h>
   52 #include <sys/fcntl.h>
   53 #include <sys/file.h>
   54 #include <sys/filedesc.h>
   55 #include <sys/filio.h>
   56 #include <sys/jail.h>
   57 #include <sys/kernel.h>
   58 #include <sys/limits.h>
   59 #include <sys/lock.h>
   60 #include <sys/malloc.h>
   61 #include <sys/mount.h>
   62 #include <sys/mqueue.h>
   63 #include <sys/mutex.h>
   64 #include <sys/namei.h>
   65 #include <sys/selinfo.h>
   66 #include <sys/pipe.h>
   67 #include <sys/priv.h>
   68 #include <sys/proc.h>
   69 #include <sys/procdesc.h>
   70 #include <sys/protosw.h>
   71 #include <sys/racct.h>
   72 #include <sys/resourcevar.h>
   73 #include <sys/signalvar.h>
   74 #include <sys/socketvar.h>
   75 #include <sys/stat.h>
   76 #include <sys/sx.h>
   77 #include <sys/syscallsubr.h>
   78 #include <sys/sysctl.h>
   79 #include <sys/sysproto.h>
   80 #include <sys/tty.h>
   81 #include <sys/unistd.h>
   82 #include <sys/un.h>
   83 #include <sys/unpcb.h>
   84 #include <sys/user.h>
   85 #include <sys/vnode.h>
   86 #ifdef KTRACE
   87 #include <sys/ktrace.h>
   88 #endif
   89 
   90 #include <net/vnet.h>
   91 
   92 #include <netinet/in.h>
   93 #include <netinet/in_pcb.h>
   94 
   95 #include <security/audit/audit.h>
   96 
   97 #include <vm/uma.h>
   98 #include <vm/vm.h>
   99 
  100 #include <ddb/ddb.h>
  101 
  102 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
  103 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
  104                      "file desc to leader structures");
  105 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
  106 
  107 static uma_zone_t file_zone;
  108 
  109 
  110 /* Flags for do_dup() */
  111 #define DUP_FIXED       0x1     /* Force fixed allocation */
  112 #define DUP_FCNTL       0x2     /* fcntl()-style errors */
  113 
  114 static int do_dup(struct thread *td, int flags, int old, int new,
  115     register_t *retval);
  116 static int      fd_first_free(struct filedesc *, int, int);
  117 static int      fd_last_used(struct filedesc *, int, int);
  118 static void     fdgrowtable(struct filedesc *, int);
  119 static void     fdunused(struct filedesc *fdp, int fd);
  120 static void     fdused(struct filedesc *fdp, int fd);
  121 static int      fill_vnode_info(struct vnode *vp, struct kinfo_file *kif);
  122 static int      fill_socket_info(struct socket *so, struct kinfo_file *kif);
  123 static int      fill_pts_info(struct tty *tp, struct kinfo_file *kif);
  124 static int      fill_pipe_info(struct pipe *pi, struct kinfo_file *kif);
  125 static int      fill_procdesc_info(struct procdesc *pdp,
  126     struct kinfo_file *kif);
  127 
  128 /*
  129  * A process is initially started out with NDFILE descriptors stored within
  130  * this structure, selected to be enough for typical applications based on
  131  * the historical limit of 20 open files (and the usage of descriptors by
  132  * shells).  If these descriptors are exhausted, a larger descriptor table
  133  * may be allocated, up to a process' resource limit; the internal arrays
  134  * are then unused.
  135  */
  136 #define NDFILE          20
  137 #define NDSLOTSIZE      sizeof(NDSLOTTYPE)
  138 #define NDENTRIES       (NDSLOTSIZE * __CHAR_BIT)
  139 #define NDSLOT(x)       ((x) / NDENTRIES)
  140 #define NDBIT(x)        ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
  141 #define NDSLOTS(x)      (((x) + NDENTRIES - 1) / NDENTRIES)
  142 
  143 /*
  144  * Storage required per open file descriptor.
  145  */
  146 #define OFILESIZE (sizeof(struct file *) + sizeof(char))
  147 
  148 /*
  149  * Storage to hold unused ofiles that need to be reclaimed.
  150  */
  151 struct freetable {
  152         struct file     **ft_table;
  153         SLIST_ENTRY(freetable) ft_next;
  154 };
  155 
  156 /*
  157  * Basic allocation of descriptors:
  158  * one of the above, plus arrays for NDFILE descriptors.
  159  */
  160 struct filedesc0 {
  161         struct  filedesc fd_fd;
  162         /*
  163          * ofiles which need to be reclaimed on free.
  164          */
  165         SLIST_HEAD(,freetable) fd_free;
  166         /*
  167          * These arrays are used when the number of open files is
  168          * <= NDFILE, and are then pointed to by the pointers above.
  169          */
  170         struct  file *fd_dfiles[NDFILE];
  171         char    fd_dfileflags[NDFILE];
  172         NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
  173 };
  174 
  175 /*
  176  * Descriptor management.
  177  */
  178 volatile int openfiles;                 /* actual number of open files */
  179 struct mtx sigio_lock;          /* mtx to protect pointers to sigio */
  180 void    (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
  181 
  182 /* A mutex to protect the association between a proc and filedesc. */
  183 static struct mtx       fdesc_mtx;
  184 
  185 /*
  186  * Find the first zero bit in the given bitmap, starting at low and not
  187  * exceeding size - 1.
  188  */
  189 static int
  190 fd_first_free(struct filedesc *fdp, int low, int size)
  191 {
  192         NDSLOTTYPE *map = fdp->fd_map;
  193         NDSLOTTYPE mask;
  194         int off, maxoff;
  195 
  196         if (low >= size)
  197                 return (low);
  198 
  199         off = NDSLOT(low);
  200         if (low % NDENTRIES) {
  201                 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
  202                 if ((mask &= ~map[off]) != 0UL)
  203                         return (off * NDENTRIES + ffsl(mask) - 1);
  204                 ++off;
  205         }
  206         for (maxoff = NDSLOTS(size); off < maxoff; ++off)
  207                 if (map[off] != ~0UL)
  208                         return (off * NDENTRIES + ffsl(~map[off]) - 1);
  209         return (size);
  210 }
  211 
  212 /*
  213  * Find the highest non-zero bit in the given bitmap, starting at low and
  214  * not exceeding size - 1.
  215  */
  216 static int
  217 fd_last_used(struct filedesc *fdp, int low, int size)
  218 {
  219         NDSLOTTYPE *map = fdp->fd_map;
  220         NDSLOTTYPE mask;
  221         int off, minoff;
  222 
  223         if (low >= size)
  224                 return (-1);
  225 
  226         off = NDSLOT(size);
  227         if (size % NDENTRIES) {
  228                 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES));
  229                 if ((mask &= map[off]) != 0)
  230                         return (off * NDENTRIES + flsl(mask) - 1);
  231                 --off;
  232         }
  233         for (minoff = NDSLOT(low); off >= minoff; --off)
  234                 if (map[off] != 0)
  235                         return (off * NDENTRIES + flsl(map[off]) - 1);
  236         return (low - 1);
  237 }
  238 
  239 static int
  240 fdisused(struct filedesc *fdp, int fd)
  241 {
  242         KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
  243             ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
  244         return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
  245 }
  246 
  247 /*
  248  * Mark a file descriptor as used.
  249  */
  250 static void
  251 fdused(struct filedesc *fdp, int fd)
  252 {
  253 
  254         FILEDESC_XLOCK_ASSERT(fdp);
  255         KASSERT(!fdisused(fdp, fd),
  256             ("fd already used"));
  257 
  258         fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
  259         if (fd > fdp->fd_lastfile)
  260                 fdp->fd_lastfile = fd;
  261         if (fd == fdp->fd_freefile)
  262                 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles);
  263 }
  264 
  265 /*
  266  * Mark a file descriptor as unused.
  267  */
  268 static void
  269 fdunused(struct filedesc *fdp, int fd)
  270 {
  271 
  272         FILEDESC_XLOCK_ASSERT(fdp);
  273         KASSERT(fdisused(fdp, fd),
  274             ("fd is already unused"));
  275         KASSERT(fdp->fd_ofiles[fd] == NULL,
  276             ("fd is still in use"));
  277 
  278         fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
  279         if (fd < fdp->fd_freefile)
  280                 fdp->fd_freefile = fd;
  281         if (fd == fdp->fd_lastfile)
  282                 fdp->fd_lastfile = fd_last_used(fdp, 0, fd);
  283 }
  284 
  285 /*
  286  * System calls on descriptors.
  287  */
  288 #ifndef _SYS_SYSPROTO_H_
  289 struct getdtablesize_args {
  290         int     dummy;
  291 };
  292 #endif
  293 /* ARGSUSED */
  294 int
  295 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
  296 {
  297         struct proc *p = td->td_proc;
  298         uint64_t lim;
  299 
  300         PROC_LOCK(p);
  301         td->td_retval[0] =
  302             min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
  303         lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
  304         PROC_UNLOCK(p);
  305         if (lim < td->td_retval[0])
  306                 td->td_retval[0] = lim;
  307         return (0);
  308 }
  309 
  310 /*
  311  * Duplicate a file descriptor to a particular value.
  312  *
  313  * Note: keep in mind that a potential race condition exists when closing
  314  * descriptors from a shared descriptor table (via rfork).
  315  */
  316 #ifndef _SYS_SYSPROTO_H_
  317 struct dup2_args {
  318         u_int   from;
  319         u_int   to;
  320 };
  321 #endif
  322 /* ARGSUSED */
  323 int
  324 sys_dup2(struct thread *td, struct dup2_args *uap)
  325 {
  326 
  327         return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to,
  328                     td->td_retval));
  329 }
  330 
  331 /*
  332  * Duplicate a file descriptor.
  333  */
  334 #ifndef _SYS_SYSPROTO_H_
  335 struct dup_args {
  336         u_int   fd;
  337 };
  338 #endif
  339 /* ARGSUSED */
  340 int
  341 sys_dup(struct thread *td, struct dup_args *uap)
  342 {
  343 
  344         return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval));
  345 }
  346 
  347 /*
  348  * The file control system call.
  349  */
  350 #ifndef _SYS_SYSPROTO_H_
  351 struct fcntl_args {
  352         int     fd;
  353         int     cmd;
  354         long    arg;
  355 };
  356 #endif
  357 /* ARGSUSED */
  358 int
  359 sys_fcntl(struct thread *td, struct fcntl_args *uap)
  360 {
  361         struct flock fl;
  362         struct oflock ofl;
  363         intptr_t arg;
  364         int error;
  365         int cmd;
  366 
  367         error = 0;
  368         cmd = uap->cmd;
  369         switch (uap->cmd) {
  370         case F_OGETLK:
  371         case F_OSETLK:
  372         case F_OSETLKW:
  373                 /*
  374                  * Convert old flock structure to new.
  375                  */
  376                 error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl));
  377                 fl.l_start = ofl.l_start;
  378                 fl.l_len = ofl.l_len;
  379                 fl.l_pid = ofl.l_pid;
  380                 fl.l_type = ofl.l_type;
  381                 fl.l_whence = ofl.l_whence;
  382                 fl.l_sysid = 0;
  383 
  384                 switch (uap->cmd) {
  385                 case F_OGETLK:
  386                     cmd = F_GETLK;
  387                     break;
  388                 case F_OSETLK:
  389                     cmd = F_SETLK;
  390                     break;
  391                 case F_OSETLKW:
  392                     cmd = F_SETLKW;
  393                     break;
  394                 }
  395                 arg = (intptr_t)&fl;
  396                 break;
  397         case F_GETLK:
  398         case F_SETLK:
  399         case F_SETLKW:
  400         case F_SETLK_REMOTE:
  401                 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl));
  402                 arg = (intptr_t)&fl;
  403                 break;
  404         default:
  405                 arg = uap->arg;
  406                 break;
  407         }
  408         if (error)
  409                 return (error);
  410         error = kern_fcntl(td, uap->fd, cmd, arg);
  411         if (error)
  412                 return (error);
  413         if (uap->cmd == F_OGETLK) {
  414                 ofl.l_start = fl.l_start;
  415                 ofl.l_len = fl.l_len;
  416                 ofl.l_pid = fl.l_pid;
  417                 ofl.l_type = fl.l_type;
  418                 ofl.l_whence = fl.l_whence;
  419                 error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl));
  420         } else if (uap->cmd == F_GETLK) {
  421                 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl));
  422         }
  423         return (error);
  424 }
  425 
  426 static inline struct file *
  427 fdtofp(int fd, struct filedesc *fdp)
  428 {
  429         struct file *fp;
  430 
  431         FILEDESC_LOCK_ASSERT(fdp);
  432         if ((unsigned)fd >= fdp->fd_nfiles ||
  433             (fp = fdp->fd_ofiles[fd]) == NULL)
  434                 return (NULL);
  435         return (fp);
  436 }
  437 
  438 static inline int
  439 fdunwrap(int fd, cap_rights_t rights, struct filedesc *fdp, struct file **fpp)
  440 {
  441 
  442         *fpp = fdtofp(fd, fdp);
  443         if (*fpp == NULL)
  444                 return (EBADF);
  445 
  446 #ifdef CAPABILITIES
  447         if ((*fpp)->f_type == DTYPE_CAPABILITY) {
  448                 int err = cap_funwrap(*fpp, rights, fpp);
  449                 if (err != 0) {
  450                         *fpp = NULL;
  451                         return (err);
  452                 }
  453         }
  454 #endif /* CAPABILITIES */
  455         return (0);
  456 }
  457 
  458 int
  459 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
  460 {
  461         struct filedesc *fdp;
  462         struct flock *flp;
  463         struct file *fp;
  464         struct proc *p;
  465         char *pop;
  466         struct vnode *vp;
  467         int error, flg, tmp;
  468         int vfslocked;
  469         u_int old, new;
  470         uint64_t bsize;
  471 
  472         vfslocked = 0;
  473         error = 0;
  474         flg = F_POSIX;
  475         p = td->td_proc;
  476         fdp = p->p_fd;
  477 
  478         switch (cmd) {
  479         case F_DUPFD:
  480                 tmp = arg;
  481                 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval);
  482                 break;
  483 
  484         case F_DUP2FD:
  485                 tmp = arg;
  486                 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval);
  487                 break;
  488 
  489         case F_GETFD:
  490                 FILEDESC_SLOCK(fdp);
  491                 if ((fp = fdtofp(fd, fdp)) == NULL) {
  492                         FILEDESC_SUNLOCK(fdp);
  493                         error = EBADF;
  494                         break;
  495                 }
  496                 pop = &fdp->fd_ofileflags[fd];
  497                 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0;
  498                 FILEDESC_SUNLOCK(fdp);
  499                 break;
  500 
  501         case F_SETFD:
  502                 FILEDESC_XLOCK(fdp);
  503                 if ((fp = fdtofp(fd, fdp)) == NULL) {
  504                         FILEDESC_XUNLOCK(fdp);
  505                         error = EBADF;
  506                         break;
  507                 }
  508                 pop = &fdp->fd_ofileflags[fd];
  509                 *pop = (*pop &~ UF_EXCLOSE) |
  510                     (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
  511                 FILEDESC_XUNLOCK(fdp);
  512                 break;
  513 
  514         case F_GETFL:
  515                 FILEDESC_SLOCK(fdp);
  516                 error = fdunwrap(fd, CAP_FCNTL, fdp, &fp);
  517                 if (error != 0) {
  518                         FILEDESC_SUNLOCK(fdp);
  519                         break;
  520                 }
  521                 td->td_retval[0] = OFLAGS(fp->f_flag);
  522                 FILEDESC_SUNLOCK(fdp);
  523                 break;
  524 
  525         case F_SETFL:
  526                 FILEDESC_SLOCK(fdp);
  527                 error = fdunwrap(fd, CAP_FCNTL, fdp, &fp);
  528                 if (error != 0) {
  529                         FILEDESC_SUNLOCK(fdp);
  530                         break;
  531                 }
  532                 fhold(fp);
  533                 FILEDESC_SUNLOCK(fdp);
  534                 do {
  535                         tmp = flg = fp->f_flag;
  536                         tmp &= ~FCNTLFLAGS;
  537                         tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
  538                 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
  539                 tmp = fp->f_flag & FNONBLOCK;
  540                 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
  541                 if (error) {
  542                         fdrop(fp, td);
  543                         break;
  544                 }
  545                 tmp = fp->f_flag & FASYNC;
  546                 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
  547                 if (error == 0) {
  548                         fdrop(fp, td);
  549                         break;
  550                 }
  551                 atomic_clear_int(&fp->f_flag, FNONBLOCK);
  552                 tmp = 0;
  553                 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
  554                 fdrop(fp, td);
  555                 break;
  556 
  557         case F_GETOWN:
  558                 FILEDESC_SLOCK(fdp);
  559                 error = fdunwrap(fd, CAP_FCNTL, fdp, &fp);
  560                 if (error != 0) {
  561                         FILEDESC_SUNLOCK(fdp);
  562                         break;
  563                 }
  564                 fhold(fp);
  565                 FILEDESC_SUNLOCK(fdp);
  566                 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
  567                 if (error == 0)
  568                         td->td_retval[0] = tmp;
  569                 fdrop(fp, td);
  570                 break;
  571 
  572         case F_SETOWN:
  573                 FILEDESC_SLOCK(fdp);
  574                 error = fdunwrap(fd, CAP_FCNTL, fdp, &fp);
  575                 if (error != 0) {
  576                         FILEDESC_SUNLOCK(fdp);
  577                         break;
  578                 }
  579                 fhold(fp);
  580                 FILEDESC_SUNLOCK(fdp);
  581                 tmp = arg;
  582                 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
  583                 fdrop(fp, td);
  584                 break;
  585 
  586         case F_SETLK_REMOTE:
  587                 error = priv_check(td, PRIV_NFS_LOCKD);
  588                 if (error)
  589                         return (error);
  590                 flg = F_REMOTE;
  591                 goto do_setlk;
  592 
  593         case F_SETLKW:
  594                 flg |= F_WAIT;
  595                 /* FALLTHROUGH F_SETLK */
  596 
  597         case F_SETLK:
  598         do_setlk:
  599                 FILEDESC_SLOCK(fdp);
  600                 error = fdunwrap(fd, CAP_FLOCK, fdp, &fp);
  601                 if (error != 0) {
  602                         FILEDESC_SUNLOCK(fdp);
  603                         break;
  604                 }
  605                 if (fp->f_type != DTYPE_VNODE) {
  606                         FILEDESC_SUNLOCK(fdp);
  607                         error = EBADF;
  608                         break;
  609                 }
  610                 flp = (struct flock *)arg;
  611                 if (flp->l_whence == SEEK_CUR) {
  612                         if (fp->f_offset < 0 ||
  613                             (flp->l_start > 0 &&
  614                              fp->f_offset > OFF_MAX - flp->l_start)) {
  615                                 FILEDESC_SUNLOCK(fdp);
  616                                 error = EOVERFLOW;
  617                                 break;
  618                         }
  619                         flp->l_start += fp->f_offset;
  620                 }
  621 
  622                 /*
  623                  * VOP_ADVLOCK() may block.
  624                  */
  625                 fhold(fp);
  626                 FILEDESC_SUNLOCK(fdp);
  627                 vp = fp->f_vnode;
  628                 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
  629                 switch (flp->l_type) {
  630                 case F_RDLCK:
  631                         if ((fp->f_flag & FREAD) == 0) {
  632                                 error = EBADF;
  633                                 break;
  634                         }
  635                         PROC_LOCK(p->p_leader);
  636                         p->p_leader->p_flag |= P_ADVLOCK;
  637                         PROC_UNLOCK(p->p_leader);
  638                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
  639                             flp, flg);
  640                         break;
  641                 case F_WRLCK:
  642                         if ((fp->f_flag & FWRITE) == 0) {
  643                                 error = EBADF;
  644                                 break;
  645                         }
  646                         PROC_LOCK(p->p_leader);
  647                         p->p_leader->p_flag |= P_ADVLOCK;
  648                         PROC_UNLOCK(p->p_leader);
  649                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
  650                             flp, flg);
  651                         break;
  652                 case F_UNLCK:
  653                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
  654                             flp, flg);
  655                         break;
  656                 case F_UNLCKSYS:
  657                         /*
  658                          * Temporary api for testing remote lock
  659                          * infrastructure.
  660                          */
  661                         if (flg != F_REMOTE) {
  662                                 error = EINVAL;
  663                                 break;
  664                         }
  665                         error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
  666                             F_UNLCKSYS, flp, flg);
  667                         break;
  668                 default:
  669                         error = EINVAL;
  670                         break;
  671                 }
  672                 VFS_UNLOCK_GIANT(vfslocked);
  673                 vfslocked = 0;
  674                 /* Check for race with close */
  675                 FILEDESC_SLOCK(fdp);
  676                 if ((unsigned) fd >= fdp->fd_nfiles ||
  677                     fp != fdp->fd_ofiles[fd]) {
  678                         FILEDESC_SUNLOCK(fdp);
  679                         flp->l_whence = SEEK_SET;
  680                         flp->l_start = 0;
  681                         flp->l_len = 0;
  682                         flp->l_type = F_UNLCK;
  683                         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
  684                         (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
  685                                            F_UNLCK, flp, F_POSIX);
  686                         VFS_UNLOCK_GIANT(vfslocked);
  687                         vfslocked = 0;
  688                 } else
  689                         FILEDESC_SUNLOCK(fdp);
  690                 fdrop(fp, td);
  691                 break;
  692 
  693         case F_GETLK:
  694                 FILEDESC_SLOCK(fdp);
  695                 error = fdunwrap(fd, CAP_FLOCK, fdp, &fp);
  696                 if (error != 0) {
  697                         FILEDESC_SUNLOCK(fdp);
  698                         break;
  699                 }
  700                 if (fp->f_type != DTYPE_VNODE) {
  701                         FILEDESC_SUNLOCK(fdp);
  702                         error = EBADF;
  703                         break;
  704                 }
  705                 flp = (struct flock *)arg;
  706                 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
  707                     flp->l_type != F_UNLCK) {
  708                         FILEDESC_SUNLOCK(fdp);
  709                         error = EINVAL;
  710                         break;
  711                 }
  712                 if (flp->l_whence == SEEK_CUR) {
  713                         if ((flp->l_start > 0 &&
  714                             fp->f_offset > OFF_MAX - flp->l_start) ||
  715                             (flp->l_start < 0 &&
  716                              fp->f_offset < OFF_MIN - flp->l_start)) {
  717                                 FILEDESC_SUNLOCK(fdp);
  718                                 error = EOVERFLOW;
  719                                 break;
  720                         }
  721                         flp->l_start += fp->f_offset;
  722                 }
  723                 /*
  724                  * VOP_ADVLOCK() may block.
  725                  */
  726                 fhold(fp);
  727                 FILEDESC_SUNLOCK(fdp);
  728                 vp = fp->f_vnode;
  729                 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
  730                 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
  731                     F_POSIX);
  732                 VFS_UNLOCK_GIANT(vfslocked);
  733                 vfslocked = 0;
  734                 fdrop(fp, td);
  735                 break;
  736 
  737         case F_RDAHEAD:
  738                 arg = arg ? 128 * 1024: 0;
  739                 /* FALLTHROUGH */
  740         case F_READAHEAD:
  741                 FILEDESC_SLOCK(fdp);
  742                 if ((fp = fdtofp(fd, fdp)) == NULL) {
  743                         FILEDESC_SUNLOCK(fdp);
  744                         error = EBADF;
  745                         break;
  746                 }
  747                 if (fp->f_type != DTYPE_VNODE) {
  748                         FILEDESC_SUNLOCK(fdp);
  749                         error = EBADF;
  750                         break;
  751                 }
  752                 fhold(fp);
  753                 FILEDESC_SUNLOCK(fdp);
  754                 if (arg != 0) {
  755                         vp = fp->f_vnode;
  756                         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
  757                         error = vn_lock(vp, LK_SHARED);
  758                         if (error != 0)
  759                                 goto readahead_vnlock_fail;
  760                         bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
  761                         VOP_UNLOCK(vp, 0);
  762                         fp->f_seqcount = (arg + bsize - 1) / bsize;
  763                         do {
  764                                 new = old = fp->f_flag;
  765                                 new |= FRDAHEAD;
  766                         } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
  767 readahead_vnlock_fail:
  768                         VFS_UNLOCK_GIANT(vfslocked);
  769                         vfslocked = 0;
  770                 } else {
  771                         do {
  772                                 new = old = fp->f_flag;
  773                                 new &= ~FRDAHEAD;
  774                         } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
  775                 }
  776                 fdrop(fp, td);
  777                 break;
  778 
  779         default:
  780                 error = EINVAL;
  781                 break;
  782         }
  783         VFS_UNLOCK_GIANT(vfslocked);
  784         return (error);
  785 }
  786 
  787 /*
  788  * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
  789  */
  790 static int
  791 do_dup(struct thread *td, int flags, int old, int new,
  792     register_t *retval)
  793 {
  794         struct filedesc *fdp;
  795         struct proc *p;
  796         struct file *fp;
  797         struct file *delfp;
  798         int error, holdleaders, maxfd;
  799 
  800         p = td->td_proc;
  801         fdp = p->p_fd;
  802 
  803         /*
  804          * Verify we have a valid descriptor to dup from and possibly to
  805          * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
  806          * return EINVAL when the new descriptor is out of bounds.
  807          */
  808         if (old < 0)
  809                 return (EBADF);
  810         if (new < 0)
  811                 return (flags & DUP_FCNTL ? EINVAL : EBADF);
  812         PROC_LOCK(p);
  813         maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
  814         PROC_UNLOCK(p);
  815         if (new >= maxfd)
  816                 return (flags & DUP_FCNTL ? EINVAL : EMFILE);
  817 
  818         FILEDESC_XLOCK(fdp);
  819         if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) {
  820                 FILEDESC_XUNLOCK(fdp);
  821                 return (EBADF);
  822         }
  823         if (flags & DUP_FIXED && old == new) {
  824                 *retval = new;
  825                 FILEDESC_XUNLOCK(fdp);
  826                 return (0);
  827         }
  828         fp = fdp->fd_ofiles[old];
  829         fhold(fp);
  830 
  831         /*
  832          * If the caller specified a file descriptor, make sure the file
  833          * table is large enough to hold it, and grab it.  Otherwise, just
  834          * allocate a new descriptor the usual way.  Since the filedesc
  835          * lock may be temporarily dropped in the process, we have to look
  836          * out for a race.
  837          */
  838         if (flags & DUP_FIXED) {
  839                 if (new >= fdp->fd_nfiles) {
  840                         /*
  841                          * The resource limits are here instead of e.g. fdalloc(),
  842                          * because the file descriptor table may be shared between
  843                          * processes, so we can't really use racct_add()/racct_sub().
  844                          * Instead of counting the number of actually allocated
  845                          * descriptors, just put the limit on the size of the file
  846                          * descriptor table.
  847                          */
  848 #ifdef RACCT
  849                         PROC_LOCK(p);
  850                         error = racct_set(p, RACCT_NOFILE, new + 1);
  851                         PROC_UNLOCK(p);
  852                         if (error != 0) {
  853                                 FILEDESC_XUNLOCK(fdp);
  854                                 fdrop(fp, td);
  855                                 return (EMFILE);
  856                         }
  857 #endif
  858                         fdgrowtable(fdp, new + 1);
  859                 }
  860                 if (fdp->fd_ofiles[new] == NULL)
  861                         fdused(fdp, new);
  862         } else {
  863                 if ((error = fdalloc(td, new, &new)) != 0) {
  864                         FILEDESC_XUNLOCK(fdp);
  865                         fdrop(fp, td);
  866                         return (error);
  867                 }
  868         }
  869 
  870         /*
  871          * If the old file changed out from under us then treat it as a
  872          * bad file descriptor.  Userland should do its own locking to
  873          * avoid this case.
  874          */
  875         if (fdp->fd_ofiles[old] != fp) {
  876                 /* we've allocated a descriptor which we won't use */
  877                 if (fdp->fd_ofiles[new] == NULL)
  878                         fdunused(fdp, new);
  879                 FILEDESC_XUNLOCK(fdp);
  880                 fdrop(fp, td);
  881                 return (EBADF);
  882         }
  883         KASSERT(old != new,
  884             ("new fd is same as old"));
  885 
  886         /*
  887          * Save info on the descriptor being overwritten.  We cannot close
  888          * it without introducing an ownership race for the slot, since we
  889          * need to drop the filedesc lock to call closef().
  890          *
  891          * XXX this duplicates parts of close().
  892          */
  893         delfp = fdp->fd_ofiles[new];
  894         holdleaders = 0;
  895         if (delfp != NULL) {
  896                 if (td->td_proc->p_fdtol != NULL) {
  897                         /*
  898                          * Ask fdfree() to sleep to ensure that all relevant
  899                          * process leaders can be traversed in closef().
  900                          */
  901                         fdp->fd_holdleaderscount++;
  902                         holdleaders = 1;
  903                 }
  904         }
  905 
  906         /*
  907          * Duplicate the source descriptor
  908          */
  909         fdp->fd_ofiles[new] = fp;
  910         fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE;
  911         if (new > fdp->fd_lastfile)
  912                 fdp->fd_lastfile = new;
  913         *retval = new;
  914 
  915         /*
  916          * If we dup'd over a valid file, we now own the reference to it
  917          * and must dispose of it using closef() semantics (as if a
  918          * close() were performed on it).
  919          *
  920          * XXX this duplicates parts of close().
  921          */
  922         if (delfp != NULL) {
  923                 knote_fdclose(td, new);
  924                 if (delfp->f_type == DTYPE_MQUEUE)
  925                         mq_fdclose(td, new, delfp);
  926                 FILEDESC_XUNLOCK(fdp);
  927                 (void) closef(delfp, td);
  928                 if (holdleaders) {
  929                         FILEDESC_XLOCK(fdp);
  930                         fdp->fd_holdleaderscount--;
  931                         if (fdp->fd_holdleaderscount == 0 &&
  932                             fdp->fd_holdleaderswakeup != 0) {
  933                                 fdp->fd_holdleaderswakeup = 0;
  934                                 wakeup(&fdp->fd_holdleaderscount);
  935                         }
  936                         FILEDESC_XUNLOCK(fdp);
  937                 }
  938         } else {
  939                 FILEDESC_XUNLOCK(fdp);
  940         }
  941         return (0);
  942 }
  943 
  944 /*
  945  * If sigio is on the list associated with a process or process group,
  946  * disable signalling from the device, remove sigio from the list and
  947  * free sigio.
  948  */
  949 void
  950 funsetown(struct sigio **sigiop)
  951 {
  952         struct sigio *sigio;
  953 
  954         SIGIO_LOCK();
  955         sigio = *sigiop;
  956         if (sigio == NULL) {
  957                 SIGIO_UNLOCK();
  958                 return;
  959         }
  960         *(sigio->sio_myref) = NULL;
  961         if ((sigio)->sio_pgid < 0) {
  962                 struct pgrp *pg = (sigio)->sio_pgrp;
  963                 PGRP_LOCK(pg);
  964                 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
  965                              sigio, sio_pgsigio);
  966                 PGRP_UNLOCK(pg);
  967         } else {
  968                 struct proc *p = (sigio)->sio_proc;
  969                 PROC_LOCK(p);
  970                 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
  971                              sigio, sio_pgsigio);
  972                 PROC_UNLOCK(p);
  973         }
  974         SIGIO_UNLOCK();
  975         crfree(sigio->sio_ucred);
  976         free(sigio, M_SIGIO);
  977 }
  978 
  979 /*
  980  * Free a list of sigio structures.
  981  * We only need to lock the SIGIO_LOCK because we have made ourselves
  982  * inaccessible to callers of fsetown and therefore do not need to lock
  983  * the proc or pgrp struct for the list manipulation.
  984  */
  985 void
  986 funsetownlst(struct sigiolst *sigiolst)
  987 {
  988         struct proc *p;
  989         struct pgrp *pg;
  990         struct sigio *sigio;
  991 
  992         sigio = SLIST_FIRST(sigiolst);
  993         if (sigio == NULL)
  994                 return;
  995         p = NULL;
  996         pg = NULL;
  997 
  998         /*
  999          * Every entry of the list should belong
 1000          * to a single proc or pgrp.
 1001          */
 1002         if (sigio->sio_pgid < 0) {
 1003                 pg = sigio->sio_pgrp;
 1004                 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED);
 1005         } else /* if (sigio->sio_pgid > 0) */ {
 1006                 p = sigio->sio_proc;
 1007                 PROC_LOCK_ASSERT(p, MA_NOTOWNED);
 1008         }
 1009 
 1010         SIGIO_LOCK();
 1011         while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
 1012                 *(sigio->sio_myref) = NULL;
 1013                 if (pg != NULL) {
 1014                         KASSERT(sigio->sio_pgid < 0,
 1015                             ("Proc sigio in pgrp sigio list"));
 1016                         KASSERT(sigio->sio_pgrp == pg,
 1017                             ("Bogus pgrp in sigio list"));
 1018                         PGRP_LOCK(pg);
 1019                         SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio,
 1020                             sio_pgsigio);
 1021                         PGRP_UNLOCK(pg);
 1022                 } else /* if (p != NULL) */ {
 1023                         KASSERT(sigio->sio_pgid > 0,
 1024                             ("Pgrp sigio in proc sigio list"));
 1025                         KASSERT(sigio->sio_proc == p,
 1026                             ("Bogus proc in sigio list"));
 1027                         PROC_LOCK(p);
 1028                         SLIST_REMOVE(&p->p_sigiolst, sigio, sigio,
 1029                             sio_pgsigio);
 1030                         PROC_UNLOCK(p);
 1031                 }
 1032                 SIGIO_UNLOCK();
 1033                 crfree(sigio->sio_ucred);
 1034                 free(sigio, M_SIGIO);
 1035                 SIGIO_LOCK();
 1036         }
 1037         SIGIO_UNLOCK();
 1038 }
 1039 
 1040 /*
 1041  * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
 1042  *
 1043  * After permission checking, add a sigio structure to the sigio list for
 1044  * the process or process group.
 1045  */
 1046 int
 1047 fsetown(pid_t pgid, struct sigio **sigiop)
 1048 {
 1049         struct proc *proc;
 1050         struct pgrp *pgrp;
 1051         struct sigio *sigio;
 1052         int ret;
 1053 
 1054         if (pgid == 0) {
 1055                 funsetown(sigiop);
 1056                 return (0);
 1057         }
 1058 
 1059         ret = 0;
 1060 
 1061         /* Allocate and fill in the new sigio out of locks. */
 1062         sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
 1063         sigio->sio_pgid = pgid;
 1064         sigio->sio_ucred = crhold(curthread->td_ucred);
 1065         sigio->sio_myref = sigiop;
 1066 
 1067         sx_slock(&proctree_lock);
 1068         if (pgid > 0) {
 1069                 proc = pfind(pgid);
 1070                 if (proc == NULL) {
 1071                         ret = ESRCH;
 1072                         goto fail;
 1073                 }
 1074 
 1075                 /*
 1076                  * Policy - Don't allow a process to FSETOWN a process
 1077                  * in another session.
 1078                  *
 1079                  * Remove this test to allow maximum flexibility or
 1080                  * restrict FSETOWN to the current process or process
 1081                  * group for maximum safety.
 1082                  */
 1083                 PROC_UNLOCK(proc);
 1084                 if (proc->p_session != curthread->td_proc->p_session) {
 1085                         ret = EPERM;
 1086                         goto fail;
 1087                 }
 1088 
 1089                 pgrp = NULL;
 1090         } else /* if (pgid < 0) */ {
 1091                 pgrp = pgfind(-pgid);
 1092                 if (pgrp == NULL) {
 1093                         ret = ESRCH;
 1094                         goto fail;
 1095                 }
 1096                 PGRP_UNLOCK(pgrp);
 1097 
 1098                 /*
 1099                  * Policy - Don't allow a process to FSETOWN a process
 1100                  * in another session.
 1101                  *
 1102                  * Remove this test to allow maximum flexibility or
 1103                  * restrict FSETOWN to the current process or process
 1104                  * group for maximum safety.
 1105                  */
 1106                 if (pgrp->pg_session != curthread->td_proc->p_session) {
 1107                         ret = EPERM;
 1108                         goto fail;
 1109                 }
 1110 
 1111                 proc = NULL;
 1112         }
 1113         funsetown(sigiop);
 1114         if (pgid > 0) {
 1115                 PROC_LOCK(proc);
 1116                 /*
 1117                  * Since funsetownlst() is called without the proctree
 1118                  * locked, we need to check for P_WEXIT.
 1119                  * XXX: is ESRCH correct?
 1120                  */
 1121                 if ((proc->p_flag & P_WEXIT) != 0) {
 1122                         PROC_UNLOCK(proc);
 1123                         ret = ESRCH;
 1124                         goto fail;
 1125                 }
 1126                 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
 1127                 sigio->sio_proc = proc;
 1128                 PROC_UNLOCK(proc);
 1129         } else {
 1130                 PGRP_LOCK(pgrp);
 1131                 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
 1132                 sigio->sio_pgrp = pgrp;
 1133                 PGRP_UNLOCK(pgrp);
 1134         }
 1135         sx_sunlock(&proctree_lock);
 1136         SIGIO_LOCK();
 1137         *sigiop = sigio;
 1138         SIGIO_UNLOCK();
 1139         return (0);
 1140 
 1141 fail:
 1142         sx_sunlock(&proctree_lock);
 1143         crfree(sigio->sio_ucred);
 1144         free(sigio, M_SIGIO);
 1145         return (ret);
 1146 }
 1147 
 1148 /*
 1149  * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
 1150  */
 1151 pid_t
 1152 fgetown(sigiop)
 1153         struct sigio **sigiop;
 1154 {
 1155         pid_t pgid;
 1156 
 1157         SIGIO_LOCK();
 1158         pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
 1159         SIGIO_UNLOCK();
 1160         return (pgid);
 1161 }
 1162 
 1163 /*
 1164  * Close a file descriptor.
 1165  */
 1166 #ifndef _SYS_SYSPROTO_H_
 1167 struct close_args {
 1168         int     fd;
 1169 };
 1170 #endif
 1171 /* ARGSUSED */
 1172 int
 1173 sys_close(td, uap)
 1174         struct thread *td;
 1175         struct close_args *uap;
 1176 {
 1177 
 1178         return (kern_close(td, uap->fd));
 1179 }
 1180 
 1181 int
 1182 kern_close(td, fd)
 1183         struct thread *td;
 1184         int fd;
 1185 {
 1186         struct filedesc *fdp;
 1187         struct file *fp, *fp_object;
 1188         int error;
 1189         int holdleaders;
 1190 
 1191         error = 0;
 1192         holdleaders = 0;
 1193         fdp = td->td_proc->p_fd;
 1194 
 1195         AUDIT_SYSCLOSE(td, fd);
 1196 
 1197         FILEDESC_XLOCK(fdp);
 1198         if ((unsigned)fd >= fdp->fd_nfiles ||
 1199             (fp = fdp->fd_ofiles[fd]) == NULL) {
 1200                 FILEDESC_XUNLOCK(fdp);
 1201                 return (EBADF);
 1202         }
 1203         fdp->fd_ofiles[fd] = NULL;
 1204         fdp->fd_ofileflags[fd] = 0;
 1205         fdunused(fdp, fd);
 1206         if (td->td_proc->p_fdtol != NULL) {
 1207                 /*
 1208                  * Ask fdfree() to sleep to ensure that all relevant
 1209                  * process leaders can be traversed in closef().
 1210                  */
 1211                 fdp->fd_holdleaderscount++;
 1212                 holdleaders = 1;
 1213         }
 1214 
 1215         /*
 1216          * We now hold the fp reference that used to be owned by the
 1217          * descriptor array.  We have to unlock the FILEDESC *AFTER*
 1218          * knote_fdclose to prevent a race of the fd getting opened, a knote
 1219          * added, and deleteing a knote for the new fd.
 1220          */
 1221         knote_fdclose(td, fd);
 1222 
 1223         /*
 1224          * When we're closing an fd with a capability, we need to notify
 1225          * mqueue if the underlying object is of type mqueue.
 1226          */
 1227         (void)cap_funwrap(fp, 0, &fp_object);
 1228         if (fp_object->f_type == DTYPE_MQUEUE)
 1229                 mq_fdclose(td, fd, fp_object);
 1230         FILEDESC_XUNLOCK(fdp);
 1231 
 1232         error = closef(fp, td);
 1233         if (holdleaders) {
 1234                 FILEDESC_XLOCK(fdp);
 1235                 fdp->fd_holdleaderscount--;
 1236                 if (fdp->fd_holdleaderscount == 0 &&
 1237                     fdp->fd_holdleaderswakeup != 0) {
 1238                         fdp->fd_holdleaderswakeup = 0;
 1239                         wakeup(&fdp->fd_holdleaderscount);
 1240                 }
 1241                 FILEDESC_XUNLOCK(fdp);
 1242         }
 1243         return (error);
 1244 }
 1245 
 1246 /*
 1247  * Close open file descriptors.
 1248  */
 1249 #ifndef _SYS_SYSPROTO_H_
 1250 struct closefrom_args {
 1251         int     lowfd;
 1252 };
 1253 #endif
 1254 /* ARGSUSED */
 1255 int
 1256 sys_closefrom(struct thread *td, struct closefrom_args *uap)
 1257 {
 1258         struct filedesc *fdp;
 1259         int fd;
 1260 
 1261         fdp = td->td_proc->p_fd;
 1262         AUDIT_ARG_FD(uap->lowfd);
 1263 
 1264         /*
 1265          * Treat negative starting file descriptor values identical to
 1266          * closefrom(0) which closes all files.
 1267          */
 1268         if (uap->lowfd < 0)
 1269                 uap->lowfd = 0;
 1270         FILEDESC_SLOCK(fdp);
 1271         for (fd = uap->lowfd; fd < fdp->fd_nfiles; fd++) {
 1272                 if (fdp->fd_ofiles[fd] != NULL) {
 1273                         FILEDESC_SUNLOCK(fdp);
 1274                         (void)kern_close(td, fd);
 1275                         FILEDESC_SLOCK(fdp);
 1276                 }
 1277         }
 1278         FILEDESC_SUNLOCK(fdp);
 1279         return (0);
 1280 }
 1281 
 1282 #if defined(COMPAT_43)
 1283 /*
 1284  * Return status information about a file descriptor.
 1285  */
 1286 #ifndef _SYS_SYSPROTO_H_
 1287 struct ofstat_args {
 1288         int     fd;
 1289         struct  ostat *sb;
 1290 };
 1291 #endif
 1292 /* ARGSUSED */
 1293 int
 1294 ofstat(struct thread *td, struct ofstat_args *uap)
 1295 {
 1296         struct ostat oub;
 1297         struct stat ub;
 1298         int error;
 1299 
 1300         error = kern_fstat(td, uap->fd, &ub);
 1301         if (error == 0) {
 1302                 cvtstat(&ub, &oub);
 1303                 error = copyout(&oub, uap->sb, sizeof(oub));
 1304         }
 1305         return (error);
 1306 }
 1307 #endif /* COMPAT_43 */
 1308 
 1309 /*
 1310  * Return status information about a file descriptor.
 1311  */
 1312 #ifndef _SYS_SYSPROTO_H_
 1313 struct fstat_args {
 1314         int     fd;
 1315         struct  stat *sb;
 1316 };
 1317 #endif
 1318 /* ARGSUSED */
 1319 int
 1320 sys_fstat(struct thread *td, struct fstat_args *uap)
 1321 {
 1322         struct stat ub;
 1323         int error;
 1324 
 1325         error = kern_fstat(td, uap->fd, &ub);
 1326         if (error == 0)
 1327                 error = copyout(&ub, uap->sb, sizeof(ub));
 1328         return (error);
 1329 }
 1330 
 1331 int
 1332 kern_fstat(struct thread *td, int fd, struct stat *sbp)
 1333 {
 1334         struct file *fp;
 1335         int error;
 1336 
 1337         AUDIT_ARG_FD(fd);
 1338 
 1339         if ((error = fget(td, fd, CAP_FSTAT, &fp)) != 0)
 1340                 return (error);
 1341 
 1342         AUDIT_ARG_FILE(td->td_proc, fp);
 1343 
 1344         error = fo_stat(fp, sbp, td->td_ucred, td);
 1345         fdrop(fp, td);
 1346 #ifdef KTRACE
 1347         if (error == 0 && KTRPOINT(td, KTR_STRUCT))
 1348                 ktrstat(sbp);
 1349 #endif
 1350         return (error);
 1351 }
 1352 
 1353 /*
 1354  * Return status information about a file descriptor.
 1355  */
 1356 #ifndef _SYS_SYSPROTO_H_
 1357 struct nfstat_args {
 1358         int     fd;
 1359         struct  nstat *sb;
 1360 };
 1361 #endif
 1362 /* ARGSUSED */
 1363 int
 1364 sys_nfstat(struct thread *td, struct nfstat_args *uap)
 1365 {
 1366         struct nstat nub;
 1367         struct stat ub;
 1368         int error;
 1369 
 1370         error = kern_fstat(td, uap->fd, &ub);
 1371         if (error == 0) {
 1372                 cvtnstat(&ub, &nub);
 1373                 error = copyout(&nub, uap->sb, sizeof(nub));
 1374         }
 1375         return (error);
 1376 }
 1377 
 1378 /*
 1379  * Return pathconf information about a file descriptor.
 1380  */
 1381 #ifndef _SYS_SYSPROTO_H_
 1382 struct fpathconf_args {
 1383         int     fd;
 1384         int     name;
 1385 };
 1386 #endif
 1387 /* ARGSUSED */
 1388 int
 1389 sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
 1390 {
 1391         struct file *fp;
 1392         struct vnode *vp;
 1393         int error;
 1394 
 1395         if ((error = fget(td, uap->fd, CAP_FPATHCONF, &fp)) != 0)
 1396                 return (error);
 1397 
 1398         /* If asynchronous I/O is available, it works for all descriptors. */
 1399         if (uap->name == _PC_ASYNC_IO) {
 1400                 td->td_retval[0] = async_io_version;
 1401                 goto out;
 1402         }
 1403         vp = fp->f_vnode;
 1404         if (vp != NULL) {
 1405                 int vfslocked;
 1406                 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 1407                 vn_lock(vp, LK_SHARED | LK_RETRY);
 1408                 error = VOP_PATHCONF(vp, uap->name, td->td_retval);
 1409                 VOP_UNLOCK(vp, 0);
 1410                 VFS_UNLOCK_GIANT(vfslocked);
 1411         } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
 1412                 if (uap->name != _PC_PIPE_BUF) {
 1413                         error = EINVAL;
 1414                 } else {
 1415                         td->td_retval[0] = PIPE_BUF;
 1416                 error = 0;
 1417                 }
 1418         } else {
 1419                 error = EOPNOTSUPP;
 1420         }
 1421 out:
 1422         fdrop(fp, td);
 1423         return (error);
 1424 }
 1425 
 1426 /*
 1427  * Grow the file table to accomodate (at least) nfd descriptors.  This may
 1428  * block and drop the filedesc lock, but it will reacquire it before
 1429  * returning.
 1430  */
 1431 static void
 1432 fdgrowtable(struct filedesc *fdp, int nfd)
 1433 {
 1434         struct filedesc0 *fdp0;
 1435         struct freetable *fo;
 1436         struct file **ntable;
 1437         struct file **otable;
 1438         char *nfileflags;
 1439         int nnfiles, onfiles;
 1440         NDSLOTTYPE *nmap;
 1441 
 1442         FILEDESC_XLOCK_ASSERT(fdp);
 1443 
 1444         KASSERT(fdp->fd_nfiles > 0,
 1445             ("zero-length file table"));
 1446 
 1447         /* compute the size of the new table */
 1448         onfiles = fdp->fd_nfiles;
 1449         nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
 1450         if (nnfiles <= onfiles)
 1451                 /* the table is already large enough */
 1452                 return;
 1453 
 1454         /* allocate a new table and (if required) new bitmaps */
 1455         FILEDESC_XUNLOCK(fdp);
 1456         ntable = malloc((nnfiles * OFILESIZE) + sizeof(struct freetable),
 1457             M_FILEDESC, M_ZERO | M_WAITOK);
 1458         nfileflags = (char *)&ntable[nnfiles];
 1459         if (NDSLOTS(nnfiles) > NDSLOTS(onfiles))
 1460                 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE,
 1461                     M_FILEDESC, M_ZERO | M_WAITOK);
 1462         else
 1463                 nmap = NULL;
 1464         FILEDESC_XLOCK(fdp);
 1465 
 1466         /*
 1467          * We now have new tables ready to go.  Since we dropped the
 1468          * filedesc lock to call malloc(), watch out for a race.
 1469          */
 1470         onfiles = fdp->fd_nfiles;
 1471         if (onfiles >= nnfiles) {
 1472                 /* we lost the race, but that's OK */
 1473                 free(ntable, M_FILEDESC);
 1474                 if (nmap != NULL)
 1475                         free(nmap, M_FILEDESC);
 1476                 return;
 1477         }
 1478         bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable));
 1479         bcopy(fdp->fd_ofileflags, nfileflags, onfiles);
 1480         otable = fdp->fd_ofiles;
 1481         fdp->fd_ofileflags = nfileflags;
 1482         fdp->fd_ofiles = ntable;
 1483         /*
 1484          * We must preserve ofiles until the process exits because we can't
 1485          * be certain that no threads have references to the old table via
 1486          * _fget().
 1487          */
 1488         if (onfiles > NDFILE) {
 1489                 fo = (struct freetable *)&otable[onfiles];
 1490                 fdp0 = (struct filedesc0 *)fdp;
 1491                 fo->ft_table = otable;
 1492                 SLIST_INSERT_HEAD(&fdp0->fd_free, fo, ft_next);
 1493         }
 1494         if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
 1495                 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap));
 1496                 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
 1497                         free(fdp->fd_map, M_FILEDESC);
 1498                 fdp->fd_map = nmap;
 1499         }
 1500         fdp->fd_nfiles = nnfiles;
 1501 }
 1502 
 1503 /*
 1504  * Allocate a file descriptor for the process.
 1505  */
 1506 int
 1507 fdalloc(struct thread *td, int minfd, int *result)
 1508 {
 1509         struct proc *p = td->td_proc;
 1510         struct filedesc *fdp = p->p_fd;
 1511         int fd = -1, maxfd;
 1512 #ifdef RACCT
 1513         int error;
 1514 #endif
 1515 
 1516         FILEDESC_XLOCK_ASSERT(fdp);
 1517 
 1518         if (fdp->fd_freefile > minfd)
 1519                 minfd = fdp->fd_freefile;          
 1520 
 1521         PROC_LOCK(p);
 1522         maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
 1523         PROC_UNLOCK(p);
 1524 
 1525         /*
 1526          * Search the bitmap for a free descriptor.  If none is found, try
 1527          * to grow the file table.  Keep at it until we either get a file
 1528          * descriptor or run into process or system limits; fdgrowtable()
 1529          * may drop the filedesc lock, so we're in a race.
 1530          */
 1531         for (;;) {
 1532                 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
 1533                 if (fd >= maxfd)
 1534                         return (EMFILE);
 1535                 if (fd < fdp->fd_nfiles)
 1536                         break;
 1537 #ifdef RACCT
 1538                 PROC_LOCK(p);
 1539                 error = racct_set(p, RACCT_NOFILE, min(fdp->fd_nfiles * 2, maxfd));
 1540                 PROC_UNLOCK(p);
 1541                 if (error != 0)
 1542                         return (EMFILE);
 1543 #endif
 1544                 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd));
 1545         }
 1546 
 1547         /*
 1548          * Perform some sanity checks, then mark the file descriptor as
 1549          * used and return it to the caller.
 1550          */
 1551         KASSERT(!fdisused(fdp, fd),
 1552             ("fd_first_free() returned non-free descriptor"));
 1553         KASSERT(fdp->fd_ofiles[fd] == NULL,
 1554             ("free descriptor isn't"));
 1555         fdp->fd_ofileflags[fd] = 0; /* XXX needed? */
 1556         fdused(fdp, fd);
 1557         *result = fd;
 1558         return (0);
 1559 }
 1560 
 1561 /*
 1562  * Check to see whether n user file descriptors are available to the process
 1563  * p.
 1564  */
 1565 int
 1566 fdavail(struct thread *td, int n)
 1567 {
 1568         struct proc *p = td->td_proc;
 1569         struct filedesc *fdp = td->td_proc->p_fd;
 1570         struct file **fpp;
 1571         int i, lim, last;
 1572 
 1573         FILEDESC_LOCK_ASSERT(fdp);
 1574 
 1575         /*
 1576          * XXX: This is only called from uipc_usrreq.c:unp_externalize();
 1577          *      call racct_add() from there instead of dealing with containers
 1578          *      here.
 1579          */
 1580         PROC_LOCK(p);
 1581         lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
 1582         PROC_UNLOCK(p);
 1583         if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
 1584                 return (1);
 1585         last = min(fdp->fd_nfiles, lim);
 1586         fpp = &fdp->fd_ofiles[fdp->fd_freefile];
 1587         for (i = last - fdp->fd_freefile; --i >= 0; fpp++) {
 1588                 if (*fpp == NULL && --n <= 0)
 1589                         return (1);
 1590         }
 1591         return (0);
 1592 }
 1593 
 1594 /*
 1595  * Create a new open file structure and allocate a file decriptor for the
 1596  * process that refers to it.  We add one reference to the file for the
 1597  * descriptor table and one reference for resultfp. This is to prevent us
 1598  * being preempted and the entry in the descriptor table closed after we
 1599  * release the FILEDESC lock.
 1600  */
 1601 int
 1602 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags)
 1603 {
 1604         struct file *fp;
 1605         int error, fd;
 1606 
 1607         error = falloc_noinstall(td, &fp);
 1608         if (error)
 1609                 return (error);         /* no reference held on error */
 1610 
 1611         error = finstall(td, fp, &fd, flags);
 1612         if (error) {
 1613                 fdrop(fp, td);          /* one reference (fp only) */
 1614                 return (error);
 1615         }
 1616 
 1617         if (resultfp != NULL)
 1618                 *resultfp = fp;         /* copy out result */
 1619         else
 1620                 fdrop(fp, td);          /* release local reference */
 1621 
 1622         if (resultfd != NULL)
 1623                 *resultfd = fd;
 1624 
 1625         return (0);
 1626 }
 1627 
 1628 /*
 1629  * Create a new open file structure without allocating a file descriptor.
 1630  */
 1631 int
 1632 falloc_noinstall(struct thread *td, struct file **resultfp)
 1633 {
 1634         struct file *fp;
 1635         int maxuserfiles = maxfiles - (maxfiles / 20);
 1636         static struct timeval lastfail;
 1637         static int curfail;
 1638 
 1639         KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
 1640 
 1641         if ((openfiles >= maxuserfiles &&
 1642             priv_check(td, PRIV_MAXFILES) != 0) ||
 1643             openfiles >= maxfiles) {
 1644                 if (ppsratecheck(&lastfail, &curfail, 1)) {
 1645                         printf("kern.maxfiles limit exceeded by uid %i, "
 1646                             "please see tuning(7).\n", td->td_ucred->cr_ruid);
 1647                 }
 1648                 return (ENFILE);
 1649         }
 1650         atomic_add_int(&openfiles, 1);
 1651         fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO);
 1652         refcount_init(&fp->f_count, 1);
 1653         fp->f_cred = crhold(td->td_ucred);
 1654         fp->f_ops = &badfileops;
 1655         fp->f_data = NULL;
 1656         fp->f_vnode = NULL;
 1657         *resultfp = fp;
 1658         return (0);
 1659 }
 1660 
 1661 /*
 1662  * Install a file in a file descriptor table.
 1663  */
 1664 int
 1665 finstall(struct thread *td, struct file *fp, int *fd, int flags)
 1666 {
 1667         struct filedesc *fdp = td->td_proc->p_fd;
 1668         int error;
 1669 
 1670         KASSERT(fd != NULL, ("%s: fd == NULL", __func__));
 1671         KASSERT(fp != NULL, ("%s: fp == NULL", __func__));
 1672 
 1673         FILEDESC_XLOCK(fdp);
 1674         if ((error = fdalloc(td, 0, fd))) {
 1675                 FILEDESC_XUNLOCK(fdp);
 1676                 return (error);
 1677         }
 1678         fhold(fp);
 1679         fdp->fd_ofiles[*fd] = fp;
 1680         if ((flags & O_CLOEXEC) != 0)
 1681                 fdp->fd_ofileflags[*fd] |= UF_EXCLOSE;
 1682         FILEDESC_XUNLOCK(fdp);
 1683         return (0);
 1684 }
 1685 
 1686 /*
 1687  * Build a new filedesc structure from another.
 1688  * Copy the current, root, and jail root vnode references.
 1689  */
 1690 struct filedesc *
 1691 fdinit(struct filedesc *fdp)
 1692 {
 1693         struct filedesc0 *newfdp;
 1694 
 1695         newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO);
 1696         FILEDESC_LOCK_INIT(&newfdp->fd_fd);
 1697         if (fdp != NULL) {
 1698                 FILEDESC_XLOCK(fdp);
 1699                 newfdp->fd_fd.fd_cdir = fdp->fd_cdir;
 1700                 if (newfdp->fd_fd.fd_cdir)
 1701                         VREF(newfdp->fd_fd.fd_cdir);
 1702                 newfdp->fd_fd.fd_rdir = fdp->fd_rdir;
 1703                 if (newfdp->fd_fd.fd_rdir)
 1704                         VREF(newfdp->fd_fd.fd_rdir);
 1705                 newfdp->fd_fd.fd_jdir = fdp->fd_jdir;
 1706                 if (newfdp->fd_fd.fd_jdir)
 1707                         VREF(newfdp->fd_fd.fd_jdir);
 1708                 FILEDESC_XUNLOCK(fdp);
 1709         }
 1710 
 1711         /* Create the file descriptor table. */
 1712         newfdp->fd_fd.fd_refcnt = 1;
 1713         newfdp->fd_fd.fd_holdcnt = 1;
 1714         newfdp->fd_fd.fd_cmask = CMASK;
 1715         newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
 1716         newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags;
 1717         newfdp->fd_fd.fd_nfiles = NDFILE;
 1718         newfdp->fd_fd.fd_map = newfdp->fd_dmap;
 1719         newfdp->fd_fd.fd_lastfile = -1;
 1720         return (&newfdp->fd_fd);
 1721 }
 1722 
 1723 static struct filedesc *
 1724 fdhold(struct proc *p)
 1725 {
 1726         struct filedesc *fdp;
 1727 
 1728         mtx_lock(&fdesc_mtx);
 1729         fdp = p->p_fd;
 1730         if (fdp != NULL)
 1731                 fdp->fd_holdcnt++;
 1732         mtx_unlock(&fdesc_mtx);
 1733         return (fdp);
 1734 }
 1735 
 1736 static void
 1737 fddrop(struct filedesc *fdp)
 1738 {
 1739         struct filedesc0 *fdp0;
 1740         struct freetable *ft;
 1741         int i;
 1742 
 1743         mtx_lock(&fdesc_mtx);
 1744         i = --fdp->fd_holdcnt;
 1745         mtx_unlock(&fdesc_mtx);
 1746         if (i > 0)
 1747                 return;
 1748 
 1749         FILEDESC_LOCK_DESTROY(fdp);
 1750         fdp0 = (struct filedesc0 *)fdp;
 1751         while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) {
 1752                 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next);
 1753                 free(ft->ft_table, M_FILEDESC);
 1754         }
 1755         free(fdp, M_FILEDESC);
 1756 }
 1757 
 1758 /*
 1759  * Share a filedesc structure.
 1760  */
 1761 struct filedesc *
 1762 fdshare(struct filedesc *fdp)
 1763 {
 1764 
 1765         FILEDESC_XLOCK(fdp);
 1766         fdp->fd_refcnt++;
 1767         FILEDESC_XUNLOCK(fdp);
 1768         return (fdp);
 1769 }
 1770 
 1771 /*
 1772  * Unshare a filedesc structure, if necessary by making a copy
 1773  */
 1774 void
 1775 fdunshare(struct proc *p, struct thread *td)
 1776 {
 1777 
 1778         FILEDESC_XLOCK(p->p_fd);
 1779         if (p->p_fd->fd_refcnt > 1) {
 1780                 struct filedesc *tmp;
 1781 
 1782                 FILEDESC_XUNLOCK(p->p_fd);
 1783                 tmp = fdcopy(p->p_fd);
 1784                 fdfree(td);
 1785                 p->p_fd = tmp;
 1786         } else
 1787                 FILEDESC_XUNLOCK(p->p_fd);
 1788 }
 1789 
 1790 /*
 1791  * Copy a filedesc structure.  A NULL pointer in returns a NULL reference,
 1792  * this is to ease callers, not catch errors.
 1793  */
 1794 struct filedesc *
 1795 fdcopy(struct filedesc *fdp)
 1796 {
 1797         struct filedesc *newfdp;
 1798         int i;
 1799 
 1800         /* Certain daemons might not have file descriptors. */
 1801         if (fdp == NULL)
 1802                 return (NULL);
 1803 
 1804         newfdp = fdinit(fdp);
 1805         FILEDESC_SLOCK(fdp);
 1806         while (fdp->fd_lastfile >= newfdp->fd_nfiles) {
 1807                 FILEDESC_SUNLOCK(fdp);
 1808                 FILEDESC_XLOCK(newfdp);
 1809                 fdgrowtable(newfdp, fdp->fd_lastfile + 1);
 1810                 FILEDESC_XUNLOCK(newfdp);
 1811                 FILEDESC_SLOCK(fdp);
 1812         }
 1813         /* copy all passable descriptors (i.e. not kqueue) */
 1814         newfdp->fd_freefile = -1;
 1815         for (i = 0; i <= fdp->fd_lastfile; ++i) {
 1816                 if (fdisused(fdp, i) &&
 1817                     (fdp->fd_ofiles[i]->f_ops->fo_flags & DFLAG_PASSABLE) &&
 1818                     fdp->fd_ofiles[i]->f_ops != &badfileops) {
 1819                         newfdp->fd_ofiles[i] = fdp->fd_ofiles[i];
 1820                         newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i];
 1821                         fhold(newfdp->fd_ofiles[i]);
 1822                         newfdp->fd_lastfile = i;
 1823                 } else {
 1824                         if (newfdp->fd_freefile == -1)
 1825                                 newfdp->fd_freefile = i;
 1826                 }
 1827         }
 1828         newfdp->fd_cmask = fdp->fd_cmask;
 1829         FILEDESC_SUNLOCK(fdp);
 1830         FILEDESC_XLOCK(newfdp);
 1831         for (i = 0; i <= newfdp->fd_lastfile; ++i)
 1832                 if (newfdp->fd_ofiles[i] != NULL)
 1833                         fdused(newfdp, i);
 1834         if (newfdp->fd_freefile == -1)
 1835                 newfdp->fd_freefile = i;
 1836         FILEDESC_XUNLOCK(newfdp);
 1837         return (newfdp);
 1838 }
 1839 
 1840 /*
 1841  * Release a filedesc structure.
 1842  */
 1843 void
 1844 fdfree(struct thread *td)
 1845 {
 1846         struct filedesc *fdp;
 1847         struct file **fpp;
 1848         int i, locked;
 1849         struct filedesc_to_leader *fdtol;
 1850         struct file *fp;
 1851         struct vnode *cdir, *jdir, *rdir, *vp;
 1852         struct flock lf;
 1853 
 1854         /* Certain daemons might not have file descriptors. */
 1855         fdp = td->td_proc->p_fd;
 1856         if (fdp == NULL)
 1857                 return;
 1858 
 1859 #ifdef RACCT
 1860         PROC_LOCK(td->td_proc);
 1861         racct_set(td->td_proc, RACCT_NOFILE, 0);
 1862         PROC_UNLOCK(td->td_proc);
 1863 #endif
 1864 
 1865         /* Check for special need to clear POSIX style locks */
 1866         fdtol = td->td_proc->p_fdtol;
 1867         if (fdtol != NULL) {
 1868                 FILEDESC_XLOCK(fdp);
 1869                 KASSERT(fdtol->fdl_refcount > 0,
 1870                         ("filedesc_to_refcount botch: fdl_refcount=%d",
 1871                          fdtol->fdl_refcount));
 1872                 if (fdtol->fdl_refcount == 1 &&
 1873                     (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
 1874                         for (i = 0, fpp = fdp->fd_ofiles;
 1875                              i <= fdp->fd_lastfile;
 1876                              i++, fpp++) {
 1877                                 if (*fpp == NULL ||
 1878                                     (*fpp)->f_type != DTYPE_VNODE)
 1879                                         continue;
 1880                                 fp = *fpp;
 1881                                 fhold(fp);
 1882                                 FILEDESC_XUNLOCK(fdp);
 1883                                 lf.l_whence = SEEK_SET;
 1884                                 lf.l_start = 0;
 1885                                 lf.l_len = 0;
 1886                                 lf.l_type = F_UNLCK;
 1887                                 vp = fp->f_vnode;
 1888                                 locked = VFS_LOCK_GIANT(vp->v_mount);
 1889                                 (void) VOP_ADVLOCK(vp,
 1890                                                    (caddr_t)td->td_proc->
 1891                                                    p_leader,
 1892                                                    F_UNLCK,
 1893                                                    &lf,
 1894                                                    F_POSIX);
 1895                                 VFS_UNLOCK_GIANT(locked);
 1896                                 FILEDESC_XLOCK(fdp);
 1897                                 fdrop(fp, td);
 1898                                 fpp = fdp->fd_ofiles + i;
 1899                         }
 1900                 }
 1901         retry:
 1902                 if (fdtol->fdl_refcount == 1) {
 1903                         if (fdp->fd_holdleaderscount > 0 &&
 1904                             (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
 1905                                 /*
 1906                                  * close() or do_dup() has cleared a reference
 1907                                  * in a shared file descriptor table.
 1908                                  */
 1909                                 fdp->fd_holdleaderswakeup = 1;
 1910                                 sx_sleep(&fdp->fd_holdleaderscount,
 1911                                     FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
 1912                                 goto retry;
 1913                         }
 1914                         if (fdtol->fdl_holdcount > 0) {
 1915                                 /*
 1916                                  * Ensure that fdtol->fdl_leader remains
 1917                                  * valid in closef().
 1918                                  */
 1919                                 fdtol->fdl_wakeup = 1;
 1920                                 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
 1921                                     "fdlhold", 0);
 1922                                 goto retry;
 1923                         }
 1924                 }
 1925                 fdtol->fdl_refcount--;
 1926                 if (fdtol->fdl_refcount == 0 &&
 1927                     fdtol->fdl_holdcount == 0) {
 1928                         fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
 1929                         fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
 1930                 } else
 1931                         fdtol = NULL;
 1932                 td->td_proc->p_fdtol = NULL;
 1933                 FILEDESC_XUNLOCK(fdp);
 1934                 if (fdtol != NULL)
 1935                         free(fdtol, M_FILEDESC_TO_LEADER);
 1936         }
 1937         FILEDESC_XLOCK(fdp);
 1938         i = --fdp->fd_refcnt;
 1939         FILEDESC_XUNLOCK(fdp);
 1940         if (i > 0)
 1941                 return;
 1942 
 1943         fpp = fdp->fd_ofiles;
 1944         for (i = fdp->fd_lastfile; i-- >= 0; fpp++) {
 1945                 if (*fpp) {
 1946                         FILEDESC_XLOCK(fdp);
 1947                         fp = *fpp;
 1948                         *fpp = NULL;
 1949                         FILEDESC_XUNLOCK(fdp);
 1950                         (void) closef(fp, td);
 1951                 }
 1952         }
 1953         FILEDESC_XLOCK(fdp);
 1954 
 1955         /* XXX This should happen earlier. */
 1956         mtx_lock(&fdesc_mtx);
 1957         td->td_proc->p_fd = NULL;
 1958         mtx_unlock(&fdesc_mtx);
 1959 
 1960         if (fdp->fd_nfiles > NDFILE)
 1961                 free(fdp->fd_ofiles, M_FILEDESC);
 1962         if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
 1963                 free(fdp->fd_map, M_FILEDESC);
 1964 
 1965         fdp->fd_nfiles = 0;
 1966 
 1967         cdir = fdp->fd_cdir;
 1968         fdp->fd_cdir = NULL;
 1969         rdir = fdp->fd_rdir;
 1970         fdp->fd_rdir = NULL;
 1971         jdir = fdp->fd_jdir;
 1972         fdp->fd_jdir = NULL;
 1973         FILEDESC_XUNLOCK(fdp);
 1974 
 1975         if (cdir) {
 1976                 locked = VFS_LOCK_GIANT(cdir->v_mount);
 1977                 vrele(cdir);
 1978                 VFS_UNLOCK_GIANT(locked);
 1979         }
 1980         if (rdir) {
 1981                 locked = VFS_LOCK_GIANT(rdir->v_mount);
 1982                 vrele(rdir);
 1983                 VFS_UNLOCK_GIANT(locked);
 1984         }
 1985         if (jdir) {
 1986                 locked = VFS_LOCK_GIANT(jdir->v_mount);
 1987                 vrele(jdir);
 1988                 VFS_UNLOCK_GIANT(locked);
 1989         }
 1990 
 1991         fddrop(fdp);
 1992 }
 1993 
 1994 /*
 1995  * For setugid programs, we don't want to people to use that setugidness
 1996  * to generate error messages which write to a file which otherwise would
 1997  * otherwise be off-limits to the process.  We check for filesystems where
 1998  * the vnode can change out from under us after execve (like [lin]procfs).
 1999  *
 2000  * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
 2001  * sufficient.  We also don't check for setugidness since we know we are.
 2002  */
 2003 static int
 2004 is_unsafe(struct file *fp)
 2005 {
 2006         if (fp->f_type == DTYPE_VNODE) {
 2007                 struct vnode *vp = fp->f_vnode;
 2008 
 2009                 if ((vp->v_vflag & VV_PROCDEP) != 0)
 2010                         return (1);
 2011         }
 2012         return (0);
 2013 }
 2014 
 2015 /*
 2016  * Make this setguid thing safe, if at all possible.
 2017  */
 2018 void
 2019 setugidsafety(struct thread *td)
 2020 {
 2021         struct filedesc *fdp;
 2022         int i;
 2023 
 2024         /* Certain daemons might not have file descriptors. */
 2025         fdp = td->td_proc->p_fd;
 2026         if (fdp == NULL)
 2027                 return;
 2028 
 2029         /*
 2030          * Note: fdp->fd_ofiles may be reallocated out from under us while
 2031          * we are blocked in a close.  Be careful!
 2032          */
 2033         FILEDESC_XLOCK(fdp);
 2034         for (i = 0; i <= fdp->fd_lastfile; i++) {
 2035                 if (i > 2)
 2036                         break;
 2037                 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) {
 2038                         struct file *fp;
 2039 
 2040                         knote_fdclose(td, i);
 2041                         /*
 2042                          * NULL-out descriptor prior to close to avoid
 2043                          * a race while close blocks.
 2044                          */
 2045                         fp = fdp->fd_ofiles[i];
 2046                         fdp->fd_ofiles[i] = NULL;
 2047                         fdp->fd_ofileflags[i] = 0;
 2048                         fdunused(fdp, i);
 2049                         FILEDESC_XUNLOCK(fdp);
 2050                         (void) closef(fp, td);
 2051                         FILEDESC_XLOCK(fdp);
 2052                 }
 2053         }
 2054         FILEDESC_XUNLOCK(fdp);
 2055 }
 2056 
 2057 /*
 2058  * If a specific file object occupies a specific file descriptor, close the
 2059  * file descriptor entry and drop a reference on the file object.  This is a
 2060  * convenience function to handle a subsequent error in a function that calls
 2061  * falloc() that handles the race that another thread might have closed the
 2062  * file descriptor out from under the thread creating the file object.
 2063  */
 2064 void
 2065 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td)
 2066 {
 2067 
 2068         FILEDESC_XLOCK(fdp);
 2069         if (fdp->fd_ofiles[idx] == fp) {
 2070                 fdp->fd_ofiles[idx] = NULL;
 2071                 fdunused(fdp, idx);
 2072                 FILEDESC_XUNLOCK(fdp);
 2073                 fdrop(fp, td);
 2074         } else
 2075                 FILEDESC_XUNLOCK(fdp);
 2076 }
 2077 
 2078 /*
 2079  * Close any files on exec?
 2080  */
 2081 void
 2082 fdcloseexec(struct thread *td)
 2083 {
 2084         struct filedesc *fdp;
 2085         int i;
 2086 
 2087         /* Certain daemons might not have file descriptors. */
 2088         fdp = td->td_proc->p_fd;
 2089         if (fdp == NULL)
 2090                 return;
 2091 
 2092         FILEDESC_XLOCK(fdp);
 2093 
 2094         /*
 2095          * We cannot cache fd_ofiles or fd_ofileflags since operations
 2096          * may block and rip them out from under us.
 2097          */
 2098         for (i = 0; i <= fdp->fd_lastfile; i++) {
 2099                 if (fdp->fd_ofiles[i] != NULL &&
 2100                     (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE ||
 2101                     (fdp->fd_ofileflags[i] & UF_EXCLOSE))) {
 2102                         struct file *fp;
 2103 
 2104                         knote_fdclose(td, i);
 2105                         /*
 2106                          * NULL-out descriptor prior to close to avoid
 2107                          * a race while close blocks.
 2108                          */
 2109                         fp = fdp->fd_ofiles[i];
 2110                         fdp->fd_ofiles[i] = NULL;
 2111                         fdp->fd_ofileflags[i] = 0;
 2112                         fdunused(fdp, i);
 2113                         if (fp->f_type == DTYPE_MQUEUE)
 2114                                 mq_fdclose(td, i, fp);
 2115                         FILEDESC_XUNLOCK(fdp);
 2116                         (void) closef(fp, td);
 2117                         FILEDESC_XLOCK(fdp);
 2118                 }
 2119         }
 2120         FILEDESC_XUNLOCK(fdp);
 2121 }
 2122 
 2123 /*
 2124  * It is unsafe for set[ug]id processes to be started with file
 2125  * descriptors 0..2 closed, as these descriptors are given implicit
 2126  * significance in the Standard C library.  fdcheckstd() will create a
 2127  * descriptor referencing /dev/null for each of stdin, stdout, and
 2128  * stderr that is not already open.
 2129  */
 2130 int
 2131 fdcheckstd(struct thread *td)
 2132 {
 2133         struct filedesc *fdp;
 2134         register_t retval, save;
 2135         int i, error, devnull;
 2136 
 2137         fdp = td->td_proc->p_fd;
 2138         if (fdp == NULL)
 2139                 return (0);
 2140         KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
 2141         devnull = -1;
 2142         error = 0;
 2143         for (i = 0; i < 3; i++) {
 2144                 if (fdp->fd_ofiles[i] != NULL)
 2145                         continue;
 2146                 if (devnull < 0) {
 2147                         save = td->td_retval[0];
 2148                         error = kern_open(td, "/dev/null", UIO_SYSSPACE,
 2149                             O_RDWR, 0);
 2150                         devnull = td->td_retval[0];
 2151                         td->td_retval[0] = save;
 2152                         if (error)
 2153                                 break;
 2154                         KASSERT(devnull == i, ("oof, we didn't get our fd"));
 2155                 } else {
 2156                         error = do_dup(td, DUP_FIXED, devnull, i, &retval);
 2157                         if (error != 0)
 2158                                 break;
 2159                 }
 2160         }
 2161         return (error);
 2162 }
 2163 
 2164 /*
 2165  * Internal form of close.  Decrement reference count on file structure.
 2166  * Note: td may be NULL when closing a file that was being passed in a
 2167  * message.
 2168  *
 2169  * XXXRW: Giant is not required for the caller, but often will be held; this
 2170  * makes it moderately likely the Giant will be recursed in the VFS case.
 2171  */
 2172 int
 2173 closef(struct file *fp, struct thread *td)
 2174 {
 2175         struct vnode *vp;
 2176         struct flock lf;
 2177         struct filedesc_to_leader *fdtol;
 2178         struct filedesc *fdp;
 2179         struct file *fp_object;
 2180 
 2181         /*
 2182          * POSIX record locking dictates that any close releases ALL
 2183          * locks owned by this process.  This is handled by setting
 2184          * a flag in the unlock to free ONLY locks obeying POSIX
 2185          * semantics, and not to free BSD-style file locks.
 2186          * If the descriptor was in a message, POSIX-style locks
 2187          * aren't passed with the descriptor, and the thread pointer
 2188          * will be NULL.  Callers should be careful only to pass a
 2189          * NULL thread pointer when there really is no owning
 2190          * context that might have locks, or the locks will be
 2191          * leaked.
 2192          *
 2193          * If this is a capability, we do lock processing under the underlying
 2194          * node, not the capability itself.
 2195          */
 2196         (void)cap_funwrap(fp, 0, &fp_object);
 2197         if ((fp_object->f_type == DTYPE_VNODE) && (td != NULL)) {
 2198                 int vfslocked;
 2199 
 2200                 vp = fp_object->f_vnode;
 2201                 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 2202                 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
 2203                         lf.l_whence = SEEK_SET;
 2204                         lf.l_start = 0;
 2205                         lf.l_len = 0;
 2206                         lf.l_type = F_UNLCK;
 2207                         (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
 2208                                            F_UNLCK, &lf, F_POSIX);
 2209                 }
 2210                 fdtol = td->td_proc->p_fdtol;
 2211                 if (fdtol != NULL) {
 2212                         /*
 2213                          * Handle special case where file descriptor table is
 2214                          * shared between multiple process leaders.
 2215                          */
 2216                         fdp = td->td_proc->p_fd;
 2217                         FILEDESC_XLOCK(fdp);
 2218                         for (fdtol = fdtol->fdl_next;
 2219                              fdtol != td->td_proc->p_fdtol;
 2220                              fdtol = fdtol->fdl_next) {
 2221                                 if ((fdtol->fdl_leader->p_flag &
 2222                                      P_ADVLOCK) == 0)
 2223                                         continue;
 2224                                 fdtol->fdl_holdcount++;
 2225                                 FILEDESC_XUNLOCK(fdp);
 2226                                 lf.l_whence = SEEK_SET;
 2227                                 lf.l_start = 0;
 2228                                 lf.l_len = 0;
 2229                                 lf.l_type = F_UNLCK;
 2230                                 vp = fp_object->f_vnode;
 2231                                 (void) VOP_ADVLOCK(vp,
 2232                                                    (caddr_t)fdtol->fdl_leader,
 2233                                                    F_UNLCK, &lf, F_POSIX);
 2234                                 FILEDESC_XLOCK(fdp);
 2235                                 fdtol->fdl_holdcount--;
 2236                                 if (fdtol->fdl_holdcount == 0 &&
 2237                                     fdtol->fdl_wakeup != 0) {
 2238                                         fdtol->fdl_wakeup = 0;
 2239                                         wakeup(fdtol);
 2240                                 }
 2241                         }
 2242                         FILEDESC_XUNLOCK(fdp);
 2243                 }
 2244                 VFS_UNLOCK_GIANT(vfslocked);
 2245         }
 2246         return (fdrop(fp, td));
 2247 }
 2248 
 2249 /*
 2250  * Initialize the file pointer with the specified properties.
 2251  * 
 2252  * The ops are set with release semantics to be certain that the flags, type,
 2253  * and data are visible when ops is.  This is to prevent ops methods from being
 2254  * called with bad data.
 2255  */
 2256 void
 2257 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
 2258 {
 2259         fp->f_data = data;
 2260         fp->f_flag = flag;
 2261         fp->f_type = type;
 2262         atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
 2263 }
 2264 
 2265 struct file *
 2266 fget_unlocked(struct filedesc *fdp, int fd)
 2267 {
 2268         struct file *fp;
 2269         u_int count;
 2270 
 2271         if (fd < 0 || fd >= fdp->fd_nfiles)
 2272                 return (NULL);
 2273         /*
 2274          * Fetch the descriptor locklessly.  We avoid fdrop() races by
 2275          * never raising a refcount above 0.  To accomplish this we have
 2276          * to use a cmpset loop rather than an atomic_add.  The descriptor
 2277          * must be re-verified once we acquire a reference to be certain
 2278          * that the identity is still correct and we did not lose a race
 2279          * due to preemption.
 2280          */
 2281         for (;;) {
 2282                 fp = fdp->fd_ofiles[fd];
 2283                 if (fp == NULL)
 2284                         break;
 2285                 count = fp->f_count;
 2286                 if (count == 0)
 2287                         continue;
 2288                 /*
 2289                  * Use an acquire barrier to prevent caching of fd_ofiles
 2290                  * so it is refreshed for verification.
 2291                  */
 2292                 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1)
 2293                         continue;
 2294                 if (fp == fdp->fd_ofiles[fd])
 2295                         break;
 2296                 fdrop(fp, curthread);
 2297         }
 2298 
 2299         return (fp);
 2300 }
 2301 
 2302 /*
 2303  * Extract the file pointer associated with the specified descriptor for the
 2304  * current user process.
 2305  *
 2306  * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
 2307  * returned.
 2308  *
 2309  * If the FGET_GETCAP flag is set, the capability itself will be returned.
 2310  * Calling _fget() with FGET_GETCAP on a non-capability will return EINVAL.
 2311  * Otherwise, if the file is a capability, its rights will be checked against
 2312  * the capability rights mask, and if successful, the object will be unwrapped.
 2313  *
 2314  * If an error occured the non-zero error is returned and *fpp is set to
 2315  * NULL.  Otherwise *fpp is held and set and zero is returned.  Caller is
 2316  * responsible for fdrop().
 2317  */
 2318 #define FGET_GETCAP     0x00000001
 2319 static __inline int
 2320 _fget(struct thread *td, int fd, struct file **fpp, int flags,
 2321     cap_rights_t needrights, cap_rights_t *haverightsp, u_char *maxprotp,
 2322     int fget_flags)
 2323 {
 2324         struct filedesc *fdp;
 2325         struct file *fp;
 2326 #ifdef CAPABILITIES
 2327         struct file *fp_fromcap;
 2328         int error;
 2329 #endif
 2330 
 2331         *fpp = NULL;
 2332         if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
 2333                 return (EBADF);
 2334         if ((fp = fget_unlocked(fdp, fd)) == NULL)
 2335                 return (EBADF);
 2336         if (fp->f_ops == &badfileops) {
 2337                 fdrop(fp, td);
 2338                 return (EBADF);
 2339         }
 2340 
 2341 #ifdef CAPABILITIES
 2342         /*
 2343          * If this is a capability, what rights does it have?
 2344          */
 2345         if (haverightsp != NULL) {
 2346                 if (fp->f_type == DTYPE_CAPABILITY)
 2347                         *haverightsp = cap_rights(fp);
 2348                 else
 2349                         *haverightsp = CAP_MASK_VALID;
 2350         }
 2351 
 2352         /*
 2353          * If a capability has been requested, return the capability directly.
 2354          * Otherwise, check capability rights, extract the underlying object,
 2355          * and check its access flags.
 2356          */
 2357         if (fget_flags & FGET_GETCAP) {
 2358                 if (fp->f_type != DTYPE_CAPABILITY) {
 2359                         fdrop(fp, td);
 2360                         return (EINVAL);
 2361                 }
 2362         } else {
 2363                 if (maxprotp == NULL)
 2364                         error = cap_funwrap(fp, needrights, &fp_fromcap);
 2365                 else
 2366                         error = cap_funwrap_mmap(fp, needrights, maxprotp,
 2367                             &fp_fromcap);
 2368                 if (error) {
 2369                         fdrop(fp, td);
 2370                         return (error);
 2371                 }
 2372 
 2373                 /*
 2374                  * If we've unwrapped a file, drop the original capability
 2375                  * and hold the new descriptor.  fp after this point refers to
 2376                  * the actual (unwrapped) object, not the capability.
 2377                  */
 2378                 if (fp != fp_fromcap) {
 2379                         fhold(fp_fromcap);
 2380                         fdrop(fp, td);
 2381                         fp = fp_fromcap;
 2382                 }
 2383         }
 2384 #else /* !CAPABILITIES */
 2385         KASSERT(fp->f_type != DTYPE_CAPABILITY,
 2386             ("%s: saw capability", __func__));
 2387         if (maxprotp != NULL)
 2388                 *maxprotp = VM_PROT_ALL;
 2389 #endif /* CAPABILITIES */
 2390 
 2391         /*
 2392          * FREAD and FWRITE failure return EBADF as per POSIX.
 2393          *
 2394          * Only one flag, or 0, may be specified.
 2395          */
 2396         if ((flags == FREAD && (fp->f_flag & FREAD) == 0) ||
 2397             (flags == FWRITE && (fp->f_flag & FWRITE) == 0)) {
 2398                 fdrop(fp, td);
 2399                 return (EBADF);
 2400         }
 2401         *fpp = fp;
 2402         return (0);
 2403 }
 2404 
 2405 int
 2406 fget(struct thread *td, int fd, cap_rights_t rights, struct file **fpp)
 2407 {
 2408 
 2409         return(_fget(td, fd, fpp, 0, rights, NULL, NULL, 0));
 2410 }
 2411 
 2412 int
 2413 fget_mmap(struct thread *td, int fd, cap_rights_t rights, u_char *maxprotp,
 2414     struct file **fpp)
 2415 {
 2416 
 2417         return (_fget(td, fd, fpp, 0, rights, NULL, maxprotp, 0));
 2418 }
 2419 
 2420 int
 2421 fget_read(struct thread *td, int fd, cap_rights_t rights, struct file **fpp)
 2422 {
 2423 
 2424         return(_fget(td, fd, fpp, FREAD, rights, NULL, NULL, 0));
 2425 }
 2426 
 2427 int
 2428 fget_write(struct thread *td, int fd, cap_rights_t rights, struct file **fpp)
 2429 {
 2430 
 2431         return (_fget(td, fd, fpp, FWRITE, rights, NULL, NULL, 0));
 2432 }
 2433 
 2434 /*
 2435  * Unlike the other fget() calls, which accept and check capability rights
 2436  * but never return capabilities, fgetcap() returns the capability but doesn't
 2437  * check capability rights.
 2438  */
 2439 int
 2440 fgetcap(struct thread *td, int fd, struct file **fpp)
 2441 {
 2442 
 2443         return (_fget(td, fd, fpp, 0, 0, NULL, NULL, FGET_GETCAP));
 2444 }
 2445 
 2446 
 2447 /*
 2448  * Like fget() but loads the underlying vnode, or returns an error if the
 2449  * descriptor does not represent a vnode.  Note that pipes use vnodes but
 2450  * never have VM objects.  The returned vnode will be vref()'d.
 2451  *
 2452  * XXX: what about the unused flags ?
 2453  */
 2454 static __inline int
 2455 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t needrights,
 2456     cap_rights_t *haverightsp, struct vnode **vpp)
 2457 {
 2458         struct file *fp;
 2459         int error;
 2460 
 2461         *vpp = NULL;
 2462         if ((error = _fget(td, fd, &fp, flags, needrights, haverightsp,
 2463             NULL, 0)) != 0)
 2464                 return (error);
 2465         if (fp->f_vnode == NULL) {
 2466                 error = EINVAL;
 2467         } else {
 2468                 *vpp = fp->f_vnode;
 2469                 vref(*vpp);
 2470         }
 2471         fdrop(fp, td);
 2472 
 2473         return (error);
 2474 }
 2475 
 2476 int
 2477 fgetvp(struct thread *td, int fd, cap_rights_t rights, struct vnode **vpp)
 2478 {
 2479 
 2480         return (_fgetvp(td, fd, 0, rights, NULL, vpp));
 2481 }
 2482 
 2483 int
 2484 fgetvp_rights(struct thread *td, int fd, cap_rights_t need, cap_rights_t *have,
 2485     struct vnode **vpp)
 2486 {
 2487         return (_fgetvp(td, fd, 0, need, have, vpp));
 2488 }
 2489 
 2490 int
 2491 fgetvp_read(struct thread *td, int fd, cap_rights_t rights, struct vnode **vpp)
 2492 {
 2493 
 2494         return (_fgetvp(td, fd, FREAD, rights, NULL, vpp));
 2495 }
 2496 
 2497 #ifdef notyet
 2498 int
 2499 fgetvp_write(struct thread *td, int fd, cap_rights_t rights,
 2500     struct vnode **vpp)
 2501 {
 2502 
 2503         return (_fgetvp(td, fd, FWRITE, rights, NULL, vpp));
 2504 }
 2505 #endif
 2506 
 2507 /*
 2508  * Like fget() but loads the underlying socket, or returns an error if the
 2509  * descriptor does not represent a socket.
 2510  *
 2511  * We bump the ref count on the returned socket.  XXX Also obtain the SX lock
 2512  * in the future.
 2513  *
 2514  * Note: fgetsock() and fputsock() are deprecated, as consumers should rely
 2515  * on their file descriptor reference to prevent the socket from being free'd
 2516  * during use.
 2517  */
 2518 int
 2519 fgetsock(struct thread *td, int fd, cap_rights_t rights, struct socket **spp,
 2520     u_int *fflagp)
 2521 {
 2522         struct file *fp;
 2523         int error;
 2524 
 2525         *spp = NULL;
 2526         if (fflagp != NULL)
 2527                 *fflagp = 0;
 2528         if ((error = _fget(td, fd, &fp, 0, rights, NULL, NULL, 0)) != 0)
 2529                 return (error);
 2530         if (fp->f_type != DTYPE_SOCKET) {
 2531                 error = ENOTSOCK;
 2532         } else {
 2533                 *spp = fp->f_data;
 2534                 if (fflagp)
 2535                         *fflagp = fp->f_flag;
 2536                 SOCK_LOCK(*spp);
 2537                 soref(*spp);
 2538                 SOCK_UNLOCK(*spp);
 2539         }
 2540         fdrop(fp, td);
 2541 
 2542         return (error);
 2543 }
 2544 
 2545 /*
 2546  * Drop the reference count on the socket and XXX release the SX lock in the
 2547  * future.  The last reference closes the socket.
 2548  *
 2549  * Note: fputsock() is deprecated, see comment for fgetsock().
 2550  */
 2551 void
 2552 fputsock(struct socket *so)
 2553 {
 2554 
 2555         ACCEPT_LOCK();
 2556         SOCK_LOCK(so);
 2557         CURVNET_SET(so->so_vnet);
 2558         sorele(so);
 2559         CURVNET_RESTORE();
 2560 }
 2561 
 2562 /*
 2563  * Handle the last reference to a file being closed.
 2564  *
 2565  * No special capability handling here, as the capability's fo_close will run
 2566  * instead of the object here, and perform any necessary drop on the object.
 2567  */
 2568 int
 2569 _fdrop(struct file *fp, struct thread *td)
 2570 {
 2571         int error;
 2572 
 2573         error = 0;
 2574         if (fp->f_count != 0)
 2575                 panic("fdrop: count %d", fp->f_count);
 2576         if (fp->f_ops != &badfileops)
 2577                 error = fo_close(fp, td);
 2578         /*
 2579          * The f_cdevpriv cannot be assigned non-NULL value while we
 2580          * are destroying the file.
 2581          */
 2582         if (fp->f_cdevpriv != NULL)
 2583                 devfs_fpdrop(fp);
 2584         atomic_subtract_int(&openfiles, 1);
 2585         crfree(fp->f_cred);
 2586         uma_zfree(file_zone, fp);
 2587 
 2588         return (error);
 2589 }
 2590 
 2591 /*
 2592  * Apply an advisory lock on a file descriptor.
 2593  *
 2594  * Just attempt to get a record lock of the requested type on the entire file
 2595  * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
 2596  */
 2597 #ifndef _SYS_SYSPROTO_H_
 2598 struct flock_args {
 2599         int     fd;
 2600         int     how;
 2601 };
 2602 #endif
 2603 /* ARGSUSED */
 2604 int
 2605 sys_flock(struct thread *td, struct flock_args *uap)
 2606 {
 2607         struct file *fp;
 2608         struct vnode *vp;
 2609         struct flock lf;
 2610         int vfslocked;
 2611         int error;
 2612 
 2613         if ((error = fget(td, uap->fd, CAP_FLOCK, &fp)) != 0)
 2614                 return (error);
 2615         if (fp->f_type != DTYPE_VNODE) {
 2616                 fdrop(fp, td);
 2617                 return (EOPNOTSUPP);
 2618         }
 2619 
 2620         vp = fp->f_vnode;
 2621         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 2622         lf.l_whence = SEEK_SET;
 2623         lf.l_start = 0;
 2624         lf.l_len = 0;
 2625         if (uap->how & LOCK_UN) {
 2626                 lf.l_type = F_UNLCK;
 2627                 atomic_clear_int(&fp->f_flag, FHASLOCK);
 2628                 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
 2629                 goto done2;
 2630         }
 2631         if (uap->how & LOCK_EX)
 2632                 lf.l_type = F_WRLCK;
 2633         else if (uap->how & LOCK_SH)
 2634                 lf.l_type = F_RDLCK;
 2635         else {
 2636                 error = EBADF;
 2637                 goto done2;
 2638         }
 2639         atomic_set_int(&fp->f_flag, FHASLOCK);
 2640         error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
 2641             (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
 2642 done2:
 2643         fdrop(fp, td);
 2644         VFS_UNLOCK_GIANT(vfslocked);
 2645         return (error);
 2646 }
 2647 /*
 2648  * Duplicate the specified descriptor to a free descriptor.
 2649  */
 2650 int
 2651 dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error)
 2652 {
 2653         struct file *wfp;
 2654         struct file *fp;
 2655 
 2656         /*
 2657          * If the to-be-dup'd fd number is greater than the allowed number
 2658          * of file descriptors, or the fd to be dup'd has already been
 2659          * closed, then reject.
 2660          */
 2661         FILEDESC_XLOCK(fdp);
 2662         if (dfd < 0 || dfd >= fdp->fd_nfiles ||
 2663             (wfp = fdp->fd_ofiles[dfd]) == NULL) {
 2664                 FILEDESC_XUNLOCK(fdp);
 2665                 return (EBADF);
 2666         }
 2667 
 2668         /*
 2669          * There are two cases of interest here.
 2670          *
 2671          * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
 2672          *
 2673          * For ENXIO steal away the file structure from (dfd) and store it in
 2674          * (indx).  (dfd) is effectively closed by this operation.
 2675          *
 2676          * Any other error code is just returned.
 2677          */
 2678         switch (error) {
 2679         case ENODEV:
 2680                 /*
 2681                  * Check that the mode the file is being opened for is a
 2682                  * subset of the mode of the existing descriptor.
 2683                  */
 2684                 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
 2685                         FILEDESC_XUNLOCK(fdp);
 2686                         return (EACCES);
 2687                 }
 2688                 fp = fdp->fd_ofiles[indx];
 2689                 fdp->fd_ofiles[indx] = wfp;
 2690                 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
 2691                 if (fp == NULL)
 2692                         fdused(fdp, indx);
 2693                 fhold(wfp);
 2694                 FILEDESC_XUNLOCK(fdp);
 2695                 if (fp != NULL)
 2696                         /*
 2697                          * We now own the reference to fp that the ofiles[]
 2698                          * array used to own.  Release it.
 2699                          */
 2700                         fdrop(fp, td);
 2701                 return (0);
 2702 
 2703         case ENXIO:
 2704                 /*
 2705                  * Steal away the file pointer from dfd and stuff it into indx.
 2706                  */
 2707                 fp = fdp->fd_ofiles[indx];
 2708                 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
 2709                 fdp->fd_ofiles[dfd] = NULL;
 2710                 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
 2711                 fdp->fd_ofileflags[dfd] = 0;
 2712                 fdunused(fdp, dfd);
 2713                 if (fp == NULL)
 2714                         fdused(fdp, indx);
 2715                 FILEDESC_XUNLOCK(fdp);
 2716 
 2717                 /*
 2718                  * We now own the reference to fp that the ofiles[] array
 2719                  * used to own.  Release it.
 2720                  */
 2721                 if (fp != NULL)
 2722                         fdrop(fp, td);
 2723                 return (0);
 2724 
 2725         default:
 2726                 FILEDESC_XUNLOCK(fdp);
 2727                 return (error);
 2728         }
 2729         /* NOTREACHED */
 2730 }
 2731 
 2732 /*
 2733  * Scan all active processes and prisons to see if any of them have a current
 2734  * or root directory of `olddp'. If so, replace them with the new mount point.
 2735  */
 2736 void
 2737 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
 2738 {
 2739         struct filedesc *fdp;
 2740         struct prison *pr;
 2741         struct proc *p;
 2742         int nrele;
 2743 
 2744         if (vrefcnt(olddp) == 1)
 2745                 return;
 2746         nrele = 0;
 2747         sx_slock(&allproc_lock);
 2748         FOREACH_PROC_IN_SYSTEM(p) {
 2749                 fdp = fdhold(p);
 2750                 if (fdp == NULL)
 2751                         continue;
 2752                 FILEDESC_XLOCK(fdp);
 2753                 if (fdp->fd_cdir == olddp) {
 2754                         vref(newdp);
 2755                         fdp->fd_cdir = newdp;
 2756                         nrele++;
 2757                 }
 2758                 if (fdp->fd_rdir == olddp) {
 2759                         vref(newdp);
 2760                         fdp->fd_rdir = newdp;
 2761                         nrele++;
 2762                 }
 2763                 if (fdp->fd_jdir == olddp) {
 2764                         vref(newdp);
 2765                         fdp->fd_jdir = newdp;
 2766                         nrele++;
 2767                 }
 2768                 FILEDESC_XUNLOCK(fdp);
 2769                 fddrop(fdp);
 2770         }
 2771         sx_sunlock(&allproc_lock);
 2772         if (rootvnode == olddp) {
 2773                 vref(newdp);
 2774                 rootvnode = newdp;
 2775                 nrele++;
 2776         }
 2777         mtx_lock(&prison0.pr_mtx);
 2778         if (prison0.pr_root == olddp) {
 2779                 vref(newdp);
 2780                 prison0.pr_root = newdp;
 2781                 nrele++;
 2782         }
 2783         mtx_unlock(&prison0.pr_mtx);
 2784         sx_slock(&allprison_lock);
 2785         TAILQ_FOREACH(pr, &allprison, pr_list) {
 2786                 mtx_lock(&pr->pr_mtx);
 2787                 if (pr->pr_root == olddp) {
 2788                         vref(newdp);
 2789                         pr->pr_root = newdp;
 2790                         nrele++;
 2791                 }
 2792                 mtx_unlock(&pr->pr_mtx);
 2793         }
 2794         sx_sunlock(&allprison_lock);
 2795         while (nrele--)
 2796                 vrele(olddp);
 2797 }
 2798 
 2799 struct filedesc_to_leader *
 2800 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
 2801 {
 2802         struct filedesc_to_leader *fdtol;
 2803 
 2804         fdtol = malloc(sizeof(struct filedesc_to_leader),
 2805                M_FILEDESC_TO_LEADER,
 2806                M_WAITOK);
 2807         fdtol->fdl_refcount = 1;
 2808         fdtol->fdl_holdcount = 0;
 2809         fdtol->fdl_wakeup = 0;
 2810         fdtol->fdl_leader = leader;
 2811         if (old != NULL) {
 2812                 FILEDESC_XLOCK(fdp);
 2813                 fdtol->fdl_next = old->fdl_next;
 2814                 fdtol->fdl_prev = old;
 2815                 old->fdl_next = fdtol;
 2816                 fdtol->fdl_next->fdl_prev = fdtol;
 2817                 FILEDESC_XUNLOCK(fdp);
 2818         } else {
 2819                 fdtol->fdl_next = fdtol;
 2820                 fdtol->fdl_prev = fdtol;
 2821         }
 2822         return (fdtol);
 2823 }
 2824 
 2825 /*
 2826  * Get file structures globally.
 2827  */
 2828 static int
 2829 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
 2830 {
 2831         struct xfile xf;
 2832         struct filedesc *fdp;
 2833         struct file *fp;
 2834         struct proc *p;
 2835         int error, n;
 2836 
 2837         error = sysctl_wire_old_buffer(req, 0);
 2838         if (error != 0)
 2839                 return (error);
 2840         if (req->oldptr == NULL) {
 2841                 n = 0;
 2842                 sx_slock(&allproc_lock);
 2843                 FOREACH_PROC_IN_SYSTEM(p) {
 2844                         if (p->p_state == PRS_NEW)
 2845                                 continue;
 2846                         fdp = fdhold(p);
 2847                         if (fdp == NULL)
 2848                                 continue;
 2849                         /* overestimates sparse tables. */
 2850                         if (fdp->fd_lastfile > 0)
 2851                                 n += fdp->fd_lastfile;
 2852                         fddrop(fdp);
 2853                 }
 2854                 sx_sunlock(&allproc_lock);
 2855                 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
 2856         }
 2857         error = 0;
 2858         bzero(&xf, sizeof(xf));
 2859         xf.xf_size = sizeof(xf);
 2860         sx_slock(&allproc_lock);
 2861         FOREACH_PROC_IN_SYSTEM(p) {
 2862                 PROC_LOCK(p);
 2863                 if (p->p_state == PRS_NEW) {
 2864                         PROC_UNLOCK(p);
 2865                         continue;
 2866                 }
 2867                 if (p_cansee(req->td, p) != 0) {
 2868                         PROC_UNLOCK(p);
 2869                         continue;
 2870                 }
 2871                 xf.xf_pid = p->p_pid;
 2872                 xf.xf_uid = p->p_ucred->cr_uid;
 2873                 PROC_UNLOCK(p);
 2874                 fdp = fdhold(p);
 2875                 if (fdp == NULL)
 2876                         continue;
 2877                 FILEDESC_SLOCK(fdp);
 2878                 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) {
 2879                         if ((fp = fdp->fd_ofiles[n]) == NULL)
 2880                                 continue;
 2881                         xf.xf_fd = n;
 2882                         xf.xf_file = fp;
 2883                         xf.xf_data = fp->f_data;
 2884                         xf.xf_vnode = fp->f_vnode;
 2885                         xf.xf_type = fp->f_type;
 2886                         xf.xf_count = fp->f_count;
 2887                         xf.xf_msgcount = 0;
 2888                         xf.xf_offset = fp->f_offset;
 2889                         xf.xf_flag = fp->f_flag;
 2890                         error = SYSCTL_OUT(req, &xf, sizeof(xf));
 2891                         if (error)
 2892                                 break;
 2893                 }
 2894                 FILEDESC_SUNLOCK(fdp);
 2895                 fddrop(fdp);
 2896                 if (error)
 2897                         break;
 2898         }
 2899         sx_sunlock(&allproc_lock);
 2900         return (error);
 2901 }
 2902 
 2903 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
 2904     0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
 2905 
 2906 #ifdef KINFO_OFILE_SIZE
 2907 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
 2908 #endif
 2909 
 2910 #ifdef COMPAT_FREEBSD7
 2911 static int
 2912 export_vnode_for_osysctl(struct vnode *vp, int type,
 2913     struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req)
 2914 {
 2915         int error;
 2916         char *fullpath, *freepath;
 2917         int vfslocked;
 2918 
 2919         bzero(kif, sizeof(*kif));
 2920         kif->kf_structsize = sizeof(*kif);
 2921 
 2922         vref(vp);
 2923         kif->kf_fd = type;
 2924         kif->kf_type = KF_TYPE_VNODE;
 2925         /* This function only handles directories. */
 2926         if (vp->v_type != VDIR) {
 2927                 vrele(vp);
 2928                 return (ENOTDIR);
 2929         }
 2930         kif->kf_vnode_type = KF_VTYPE_VDIR;
 2931 
 2932         /*
 2933          * This is not a true file descriptor, so we set a bogus refcount
 2934          * and offset to indicate these fields should be ignored.
 2935          */
 2936         kif->kf_ref_count = -1;
 2937         kif->kf_offset = -1;
 2938 
 2939         freepath = NULL;
 2940         fullpath = "-";
 2941         FILEDESC_SUNLOCK(fdp);
 2942         vn_fullpath(curthread, vp, &fullpath, &freepath);
 2943         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 2944         vrele(vp);
 2945         VFS_UNLOCK_GIANT(vfslocked);
 2946         strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
 2947         if (freepath != NULL)
 2948                 free(freepath, M_TEMP);
 2949         error = SYSCTL_OUT(req, kif, sizeof(*kif));
 2950         FILEDESC_SLOCK(fdp);
 2951         return (error);
 2952 }
 2953 
 2954 /*
 2955  * Get per-process file descriptors for use by procstat(1), et al.
 2956  */
 2957 static int
 2958 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
 2959 {
 2960         char *fullpath, *freepath;
 2961         struct kinfo_ofile *kif;
 2962         struct filedesc *fdp;
 2963         int error, i, *name;
 2964         struct socket *so;
 2965         struct vnode *vp;
 2966         struct file *fp;
 2967         struct proc *p;
 2968         struct tty *tp;
 2969         int vfslocked;
 2970 
 2971         name = (int *)arg1;
 2972         if ((p = pfind((pid_t)name[0])) == NULL)
 2973                 return (ESRCH);
 2974         if ((error = p_candebug(curthread, p))) {
 2975                 PROC_UNLOCK(p);
 2976                 return (error);
 2977         }
 2978         fdp = fdhold(p);
 2979         PROC_UNLOCK(p);
 2980         if (fdp == NULL)
 2981                 return (ENOENT);
 2982         kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
 2983         FILEDESC_SLOCK(fdp);
 2984         if (fdp->fd_cdir != NULL)
 2985                 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
 2986                                 fdp, req);
 2987         if (fdp->fd_rdir != NULL)
 2988                 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
 2989                                 fdp, req);
 2990         if (fdp->fd_jdir != NULL)
 2991                 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
 2992                                 fdp, req);
 2993         for (i = 0; i < fdp->fd_nfiles; i++) {
 2994                 if ((fp = fdp->fd_ofiles[i]) == NULL)
 2995                         continue;
 2996                 bzero(kif, sizeof(*kif));
 2997                 kif->kf_structsize = sizeof(*kif);
 2998                 vp = NULL;
 2999                 so = NULL;
 3000                 tp = NULL;
 3001                 kif->kf_fd = i;
 3002 
 3003 #ifdef CAPABILITIES
 3004                 /*
 3005                  * When reporting a capability, most fields will be from the
 3006                  * underlying object, but do mark as a capability. With
 3007                  * ofiledesc, we don't have a field to export the cap_rights_t,
 3008                  * but we do with the new filedesc.
 3009                  */
 3010                 if (fp->f_type == DTYPE_CAPABILITY) {
 3011                         kif->kf_flags |= KF_FLAG_CAPABILITY;
 3012                         (void)cap_funwrap(fp, 0, &fp);
 3013                 }
 3014 #else
 3015                 KASSERT(fp->f_type != DTYPE_CAPABILITY,
 3016                     ("sysctl_kern_proc_ofiledesc: saw capability"));
 3017 #endif
 3018                 switch (fp->f_type) {
 3019                 case DTYPE_VNODE:
 3020                         kif->kf_type = KF_TYPE_VNODE;
 3021                         vp = fp->f_vnode;
 3022                         break;
 3023 
 3024                 case DTYPE_SOCKET:
 3025                         kif->kf_type = KF_TYPE_SOCKET;
 3026                         so = fp->f_data;
 3027                         break;
 3028 
 3029                 case DTYPE_PIPE:
 3030                         kif->kf_type = KF_TYPE_PIPE;
 3031                         break;
 3032 
 3033                 case DTYPE_FIFO:
 3034                         kif->kf_type = KF_TYPE_FIFO;
 3035                         vp = fp->f_vnode;
 3036                         break;
 3037 
 3038                 case DTYPE_KQUEUE:
 3039                         kif->kf_type = KF_TYPE_KQUEUE;
 3040                         break;
 3041 
 3042                 case DTYPE_CRYPTO:
 3043                         kif->kf_type = KF_TYPE_CRYPTO;
 3044                         break;
 3045 
 3046                 case DTYPE_MQUEUE:
 3047                         kif->kf_type = KF_TYPE_MQUEUE;
 3048                         break;
 3049 
 3050                 case DTYPE_SHM:
 3051                         kif->kf_type = KF_TYPE_SHM;
 3052                         break;
 3053 
 3054                 case DTYPE_SEM:
 3055                         kif->kf_type = KF_TYPE_SEM;
 3056                         break;
 3057 
 3058                 case DTYPE_PTS:
 3059                         kif->kf_type = KF_TYPE_PTS;
 3060                         tp = fp->f_data;
 3061                         break;
 3062 
 3063 #ifdef PROCDESC
 3064                 case DTYPE_PROCDESC:
 3065                         kif->kf_type = KF_TYPE_PROCDESC;
 3066                         break;
 3067 #endif
 3068 
 3069                 default:
 3070                         kif->kf_type = KF_TYPE_UNKNOWN;
 3071                         break;
 3072                 }
 3073                 kif->kf_ref_count = fp->f_count;
 3074                 if (fp->f_flag & FREAD)
 3075                         kif->kf_flags |= KF_FLAG_READ;
 3076                 if (fp->f_flag & FWRITE)
 3077                         kif->kf_flags |= KF_FLAG_WRITE;
 3078                 if (fp->f_flag & FAPPEND)
 3079                         kif->kf_flags |= KF_FLAG_APPEND;
 3080                 if (fp->f_flag & FASYNC)
 3081                         kif->kf_flags |= KF_FLAG_ASYNC;
 3082                 if (fp->f_flag & FFSYNC)
 3083                         kif->kf_flags |= KF_FLAG_FSYNC;
 3084                 if (fp->f_flag & FNONBLOCK)
 3085                         kif->kf_flags |= KF_FLAG_NONBLOCK;
 3086                 if (fp->f_flag & O_DIRECT)
 3087                         kif->kf_flags |= KF_FLAG_DIRECT;
 3088                 if (fp->f_flag & FHASLOCK)
 3089                         kif->kf_flags |= KF_FLAG_HASLOCK;
 3090                 kif->kf_offset = fp->f_offset;
 3091                 if (vp != NULL) {
 3092                         vref(vp);
 3093                         switch (vp->v_type) {
 3094                         case VNON:
 3095                                 kif->kf_vnode_type = KF_VTYPE_VNON;
 3096                                 break;
 3097                         case VREG:
 3098                                 kif->kf_vnode_type = KF_VTYPE_VREG;
 3099                                 break;
 3100                         case VDIR:
 3101                                 kif->kf_vnode_type = KF_VTYPE_VDIR;
 3102                                 break;
 3103                         case VBLK:
 3104                                 kif->kf_vnode_type = KF_VTYPE_VBLK;
 3105                                 break;
 3106                         case VCHR:
 3107                                 kif->kf_vnode_type = KF_VTYPE_VCHR;
 3108                                 break;
 3109                         case VLNK:
 3110                                 kif->kf_vnode_type = KF_VTYPE_VLNK;
 3111                                 break;
 3112                         case VSOCK:
 3113                                 kif->kf_vnode_type = KF_VTYPE_VSOCK;
 3114                                 break;
 3115                         case VFIFO:
 3116                                 kif->kf_vnode_type = KF_VTYPE_VFIFO;
 3117                                 break;
 3118                         case VBAD:
 3119                                 kif->kf_vnode_type = KF_VTYPE_VBAD;
 3120                                 break;
 3121                         default:
 3122                                 kif->kf_vnode_type = KF_VTYPE_UNKNOWN;
 3123                                 break;
 3124                         }
 3125                         /*
 3126                          * It is OK to drop the filedesc lock here as we will
 3127                          * re-validate and re-evaluate its properties when
 3128                          * the loop continues.
 3129                          */
 3130                         freepath = NULL;
 3131                         fullpath = "-";
 3132                         FILEDESC_SUNLOCK(fdp);
 3133                         vn_fullpath(curthread, vp, &fullpath, &freepath);
 3134                         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 3135                         vrele(vp);
 3136                         VFS_UNLOCK_GIANT(vfslocked);
 3137                         strlcpy(kif->kf_path, fullpath,
 3138                             sizeof(kif->kf_path));
 3139                         if (freepath != NULL)
 3140                                 free(freepath, M_TEMP);
 3141                         FILEDESC_SLOCK(fdp);
 3142                 }
 3143                 if (so != NULL) {
 3144                         struct sockaddr *sa;
 3145 
 3146                         if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa)
 3147                             == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
 3148                                 bcopy(sa, &kif->kf_sa_local, sa->sa_len);
 3149                                 free(sa, M_SONAME);
 3150                         }
 3151                         if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa)
 3152                             == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
 3153                                 bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
 3154                                 free(sa, M_SONAME);
 3155                         }
 3156                         kif->kf_sock_domain =
 3157                             so->so_proto->pr_domain->dom_family;
 3158                         kif->kf_sock_type = so->so_type;
 3159                         kif->kf_sock_protocol = so->so_proto->pr_protocol;
 3160                 }
 3161                 if (tp != NULL) {
 3162                         strlcpy(kif->kf_path, tty_devname(tp),
 3163                             sizeof(kif->kf_path));
 3164                 }
 3165                 error = SYSCTL_OUT(req, kif, sizeof(*kif));
 3166                 if (error)
 3167                         break;
 3168         }
 3169         FILEDESC_SUNLOCK(fdp);
 3170         fddrop(fdp);
 3171         free(kif, M_TEMP);
 3172         return (0);
 3173 }
 3174 
 3175 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD,
 3176     sysctl_kern_proc_ofiledesc, "Process ofiledesc entries");
 3177 #endif  /* COMPAT_FREEBSD7 */
 3178 
 3179 #ifdef KINFO_FILE_SIZE
 3180 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
 3181 #endif
 3182 
 3183 static int
 3184 export_fd_for_sysctl(void *data, int type, int fd, int fflags, int refcnt,
 3185     int64_t offset, int fd_is_cap, cap_rights_t fd_cap_rights,
 3186     struct kinfo_file *kif, struct sysctl_req *req)
 3187 {
 3188         struct {
 3189                 int     fflag;
 3190                 int     kf_fflag;
 3191         } fflags_table[] = {
 3192                 { FAPPEND, KF_FLAG_APPEND },
 3193                 { FASYNC, KF_FLAG_ASYNC },
 3194                 { FFSYNC, KF_FLAG_FSYNC },
 3195                 { FHASLOCK, KF_FLAG_HASLOCK },
 3196                 { FNONBLOCK, KF_FLAG_NONBLOCK },
 3197                 { FREAD, KF_FLAG_READ },
 3198                 { FWRITE, KF_FLAG_WRITE },
 3199                 { O_CREAT, KF_FLAG_CREAT },
 3200                 { O_DIRECT, KF_FLAG_DIRECT },
 3201                 { O_EXCL, KF_FLAG_EXCL },
 3202                 { O_EXEC, KF_FLAG_EXEC },
 3203                 { O_EXLOCK, KF_FLAG_EXLOCK },
 3204                 { O_NOFOLLOW, KF_FLAG_NOFOLLOW },
 3205                 { O_SHLOCK, KF_FLAG_SHLOCK },
 3206                 { O_TRUNC, KF_FLAG_TRUNC }
 3207         };
 3208 #define NFFLAGS (sizeof(fflags_table) / sizeof(*fflags_table))
 3209         struct vnode *vp;
 3210         int error, vfslocked;
 3211         unsigned int i;
 3212 
 3213         bzero(kif, sizeof(*kif));
 3214         switch (type) {
 3215         case KF_TYPE_FIFO:
 3216         case KF_TYPE_VNODE:
 3217                 vp = (struct vnode *)data;
 3218                 error = fill_vnode_info(vp, kif);
 3219                 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 3220                 vrele(vp);
 3221                 VFS_UNLOCK_GIANT(vfslocked);
 3222                 break;
 3223         case KF_TYPE_SOCKET:
 3224                 error = fill_socket_info((struct socket *)data, kif);
 3225                 break;
 3226         case KF_TYPE_PIPE:
 3227                 error = fill_pipe_info((struct pipe *)data, kif);
 3228                 break;
 3229         case KF_TYPE_PTS:
 3230                 error = fill_pts_info((struct tty *)data, kif);
 3231                 break;
 3232         case KF_TYPE_PROCDESC:
 3233                 error = fill_procdesc_info((struct procdesc *)data, kif);
 3234                 break;
 3235         default:
 3236                 error = 0;
 3237         }
 3238         if (error == 0)
 3239                 kif->kf_status |= KF_ATTR_VALID;
 3240 
 3241         /*
 3242          * Translate file access flags.
 3243          */
 3244         for (i = 0; i < NFFLAGS; i++)
 3245                 if (fflags & fflags_table[i].fflag)
 3246                         kif->kf_flags |=  fflags_table[i].kf_fflag;
 3247         if (fd_is_cap)
 3248                 kif->kf_flags |= KF_FLAG_CAPABILITY;
 3249         if (fd_is_cap)
 3250                 kif->kf_cap_rights = fd_cap_rights;
 3251         kif->kf_fd = fd;
 3252         kif->kf_type = type;
 3253         kif->kf_ref_count = refcnt;
 3254         kif->kf_offset = offset;
 3255         /* Pack record size down */
 3256         kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
 3257             strlen(kif->kf_path) + 1;
 3258         kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
 3259         error = SYSCTL_OUT(req, kif, kif->kf_structsize);
 3260         return (error);
 3261 }
 3262 
 3263 /*
 3264  * Get per-process file descriptors for use by procstat(1), et al.
 3265  */
 3266 static int
 3267 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
 3268 {
 3269         struct file *fp;
 3270         struct filedesc *fdp;
 3271         struct kinfo_file *kif;
 3272         struct proc *p;
 3273         struct vnode *cttyvp, *textvp, *tracevp;
 3274         size_t oldidx;
 3275         int64_t offset;
 3276         void *data;
 3277         int error, i, *name;
 3278         int fd_is_cap, type, refcnt, fflags;
 3279         cap_rights_t fd_cap_rights;
 3280 
 3281         name = (int *)arg1;
 3282         if ((p = pfind((pid_t)name[0])) == NULL)
 3283                 return (ESRCH);
 3284         if ((error = p_candebug(curthread, p))) {
 3285                 PROC_UNLOCK(p);
 3286                 return (error);
 3287         }
 3288         /* ktrace vnode */
 3289         tracevp = p->p_tracevp;
 3290         if (tracevp != NULL)
 3291                 vref(tracevp);
 3292         /* text vnode */
 3293         textvp = p->p_textvp;
 3294         if (textvp != NULL)
 3295                 vref(textvp);
 3296         /* Controlling tty. */
 3297         cttyvp = NULL;
 3298         if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
 3299                 cttyvp = p->p_pgrp->pg_session->s_ttyvp;
 3300                 if (cttyvp != NULL)
 3301                         vref(cttyvp);
 3302         }
 3303         fdp = fdhold(p);
 3304         PROC_UNLOCK(p);
 3305         kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
 3306         if (tracevp != NULL)
 3307                 export_fd_for_sysctl(tracevp, KF_TYPE_VNODE, KF_FD_TYPE_TRACE,
 3308                     FREAD | FWRITE, -1, -1, 0, 0, kif, req);
 3309         if (textvp != NULL)
 3310                 export_fd_for_sysctl(textvp, KF_TYPE_VNODE, KF_FD_TYPE_TEXT,
 3311                     FREAD, -1, -1, 0, 0, kif, req);
 3312         if (cttyvp != NULL)
 3313                 export_fd_for_sysctl(cttyvp, KF_TYPE_VNODE, KF_FD_TYPE_CTTY,
 3314                     FREAD | FWRITE, -1, -1, 0, 0, kif, req);
 3315         if (fdp == NULL)
 3316                 goto fail;
 3317         FILEDESC_SLOCK(fdp);
 3318         /* working directory */
 3319         if (fdp->fd_cdir != NULL) {
 3320                 vref(fdp->fd_cdir);
 3321                 data = fdp->fd_cdir;
 3322                 FILEDESC_SUNLOCK(fdp);
 3323                 export_fd_for_sysctl(data, KF_TYPE_VNODE, KF_FD_TYPE_CWD,
 3324                     FREAD, -1, -1, 0, 0, kif, req);
 3325                 FILEDESC_SLOCK(fdp);
 3326         }
 3327         /* root directory */
 3328         if (fdp->fd_rdir != NULL) {
 3329                 vref(fdp->fd_rdir);
 3330                 data = fdp->fd_rdir;
 3331                 FILEDESC_SUNLOCK(fdp);
 3332                 export_fd_for_sysctl(data, KF_TYPE_VNODE, KF_FD_TYPE_ROOT,
 3333                     FREAD, -1, -1, 0, 0, kif, req);
 3334                 FILEDESC_SLOCK(fdp);
 3335         }
 3336         /* jail directory */
 3337         if (fdp->fd_jdir != NULL) {
 3338                 vref(fdp->fd_jdir);
 3339                 data = fdp->fd_jdir;
 3340                 FILEDESC_SUNLOCK(fdp);
 3341                 export_fd_for_sysctl(data, KF_TYPE_VNODE, KF_FD_TYPE_JAIL,
 3342                     FREAD, -1, -1, 0, 0, kif, req);
 3343                 FILEDESC_SLOCK(fdp);
 3344         }
 3345         for (i = 0; i < fdp->fd_nfiles; i++) {
 3346                 if ((fp = fdp->fd_ofiles[i]) == NULL)
 3347                         continue;
 3348                 data = NULL;
 3349                 fd_is_cap = 0;
 3350                 fd_cap_rights = 0;
 3351 
 3352 #ifdef CAPABILITIES
 3353                 /*
 3354                  * When reporting a capability, most fields will be from the
 3355                  * underlying object, but do mark as a capability and export
 3356                  * the capability rights mask.
 3357                  */
 3358                 if (fp->f_type == DTYPE_CAPABILITY) {
 3359                         fd_is_cap = 1;
 3360                         fd_cap_rights = cap_rights(fp);
 3361                         (void)cap_funwrap(fp, 0, &fp);
 3362                 }
 3363 #else /* !CAPABILITIES */
 3364                 KASSERT(fp->f_type != DTYPE_CAPABILITY,
 3365                     ("sysctl_kern_proc_filedesc: saw capability"));
 3366 #endif
 3367                 switch (fp->f_type) {
 3368                 case DTYPE_VNODE:
 3369                         type = KF_TYPE_VNODE;
 3370                         vref(fp->f_vnode);
 3371                         data = fp->f_vnode;
 3372                         break;
 3373 
 3374                 case DTYPE_SOCKET:
 3375                         type = KF_TYPE_SOCKET;
 3376                         data = fp->f_data;
 3377                         break;
 3378 
 3379                 case DTYPE_PIPE:
 3380                         type = KF_TYPE_PIPE;
 3381                         data = fp->f_data;
 3382                         break;
 3383 
 3384                 case DTYPE_FIFO:
 3385                         type = KF_TYPE_FIFO;
 3386                         vref(fp->f_vnode);
 3387                         data = fp->f_vnode;
 3388                         break;
 3389 
 3390                 case DTYPE_KQUEUE:
 3391                         type = KF_TYPE_KQUEUE;
 3392                         break;
 3393 
 3394                 case DTYPE_CRYPTO:
 3395                         type = KF_TYPE_CRYPTO;
 3396                         break;
 3397 
 3398                 case DTYPE_MQUEUE:
 3399                         type = KF_TYPE_MQUEUE;
 3400                         break;
 3401 
 3402                 case DTYPE_SHM:
 3403                         type = KF_TYPE_SHM;
 3404                         break;
 3405 
 3406                 case DTYPE_SEM:
 3407                         type = KF_TYPE_SEM;
 3408                         break;
 3409 
 3410                 case DTYPE_PTS:
 3411                         type = KF_TYPE_PTS;
 3412                         data = fp->f_data;
 3413                         break;
 3414 
 3415 #ifdef PROCDESC
 3416                 case DTYPE_PROCDESC:
 3417                         type = KF_TYPE_PROCDESC;
 3418                         data = fp->f_data;
 3419                         break;
 3420 #endif
 3421 
 3422                 default:
 3423                         type = KF_TYPE_UNKNOWN;
 3424                         break;
 3425                 }
 3426                 refcnt = fp->f_count;
 3427                 fflags = fp->f_flag;
 3428                 offset = fp->f_offset;
 3429 
 3430                 /*
 3431                  * Create sysctl entry.
 3432                  * It is OK to drop the filedesc lock here as we will
 3433                  * re-validate and re-evaluate its properties when
 3434                  * the loop continues.
 3435                  */
 3436                 oldidx = req->oldidx;
 3437                 if (type == KF_TYPE_VNODE || type == KF_TYPE_FIFO)
 3438                         FILEDESC_SUNLOCK(fdp);
 3439                 error = export_fd_for_sysctl(data, type, i, fflags, refcnt,
 3440                     offset, fd_is_cap, fd_cap_rights, kif, req);
 3441                 if (type == KF_TYPE_VNODE || type == KF_TYPE_FIFO)
 3442                         FILEDESC_SLOCK(fdp);
 3443                 if (error) {
 3444                         if (error == ENOMEM) {
 3445                                 /*
 3446                                  * The hack to keep the ABI of sysctl
 3447                                  * kern.proc.filedesc intact, but not
 3448                                  * to account a partially copied
 3449                                  * kinfo_file into the oldidx.
 3450                                  */
 3451                                 req->oldidx = oldidx;
 3452                                 error = 0;
 3453                         }
 3454                         break;
 3455                 }
 3456         }
 3457         FILEDESC_SUNLOCK(fdp);
 3458 fail:
 3459         if (fdp != NULL)
 3460                 fddrop(fdp);
 3461         free(kif, M_TEMP);
 3462         return (error);
 3463 }
 3464 
 3465 int
 3466 vntype_to_kinfo(int vtype)
 3467 {
 3468         struct {
 3469                 int     vtype;
 3470                 int     kf_vtype;
 3471         } vtypes_table[] = {
 3472                 { VBAD, KF_VTYPE_VBAD },
 3473                 { VBLK, KF_VTYPE_VBLK },
 3474                 { VCHR, KF_VTYPE_VCHR },
 3475                 { VDIR, KF_VTYPE_VDIR },
 3476                 { VFIFO, KF_VTYPE_VFIFO },
 3477                 { VLNK, KF_VTYPE_VLNK },
 3478                 { VNON, KF_VTYPE_VNON },
 3479                 { VREG, KF_VTYPE_VREG },
 3480                 { VSOCK, KF_VTYPE_VSOCK }
 3481         };
 3482 #define NVTYPES (sizeof(vtypes_table) / sizeof(*vtypes_table))
 3483         unsigned int i;
 3484 
 3485         /*
 3486          * Perform vtype translation.
 3487          */
 3488         for (i = 0; i < NVTYPES; i++)
 3489                 if (vtypes_table[i].vtype == vtype)
 3490                         break;
 3491         if (i < NVTYPES)
 3492                 return (vtypes_table[i].kf_vtype);
 3493 
 3494         return (KF_VTYPE_UNKNOWN);
 3495 }
 3496 
 3497 static int
 3498 fill_vnode_info(struct vnode *vp, struct kinfo_file *kif)
 3499 {
 3500         struct vattr va;
 3501         char *fullpath, *freepath;
 3502         int error, vfslocked;
 3503 
 3504         if (vp == NULL)
 3505                 return (1);
 3506         kif->kf_vnode_type = vntype_to_kinfo(vp->v_type);
 3507         freepath = NULL;
 3508         fullpath = "-";
 3509         error = vn_fullpath(curthread, vp, &fullpath, &freepath);
 3510         if (error == 0) {
 3511                 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
 3512         }
 3513         if (freepath != NULL)
 3514                 free(freepath, M_TEMP);
 3515 
 3516         /*
 3517          * Retrieve vnode attributes.
 3518          */
 3519         va.va_fsid = VNOVAL;
 3520         va.va_rdev = NODEV;
 3521         vfslocked = VFS_LOCK_GIANT(vp->v_mount);
 3522         vn_lock(vp, LK_SHARED | LK_RETRY);
 3523         error = VOP_GETATTR(vp, &va, curthread->td_ucred);
 3524         VOP_UNLOCK(vp, 0);
 3525         VFS_UNLOCK_GIANT(vfslocked);
 3526         if (error != 0)
 3527                 return (error);
 3528         if (va.va_fsid != VNOVAL)
 3529                 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
 3530         else
 3531                 kif->kf_un.kf_file.kf_file_fsid =
 3532                     vp->v_mount->mnt_stat.f_fsid.val[0];
 3533         kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
 3534         kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
 3535         kif->kf_un.kf_file.kf_file_size = va.va_size;
 3536         kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
 3537         return (0);
 3538 }
 3539 
 3540 static int
 3541 fill_socket_info(struct socket *so, struct kinfo_file *kif)
 3542 {
 3543         struct sockaddr *sa;
 3544         struct inpcb *inpcb;
 3545         struct unpcb *unpcb;
 3546         int error;
 3547 
 3548         if (so == NULL)
 3549                 return (1);
 3550         kif->kf_sock_domain = so->so_proto->pr_domain->dom_family;
 3551         kif->kf_sock_type = so->so_type;
 3552         kif->kf_sock_protocol = so->so_proto->pr_protocol;
 3553         kif->kf_un.kf_sock.kf_sock_pcb = (uintptr_t)so->so_pcb;
 3554         switch(kif->kf_sock_domain) {
 3555         case AF_INET:
 3556         case AF_INET6:
 3557                 if (kif->kf_sock_protocol == IPPROTO_TCP) {
 3558                         if (so->so_pcb != NULL) {
 3559                                 inpcb = (struct inpcb *)(so->so_pcb);
 3560                                 kif->kf_un.kf_sock.kf_sock_inpcb =
 3561                                     (uintptr_t)inpcb->inp_ppcb;
 3562                         }
 3563                 }
 3564                 break;
 3565         case AF_UNIX:
 3566                 if (so->so_pcb != NULL) {
 3567                         unpcb = (struct unpcb *)(so->so_pcb);
 3568                         if (unpcb->unp_conn) {
 3569                                 kif->kf_un.kf_sock.kf_sock_unpconn =
 3570                                     (uintptr_t)unpcb->unp_conn;
 3571                                 kif->kf_un.kf_sock.kf_sock_rcv_sb_state =
 3572                                     so->so_rcv.sb_state;
 3573                                 kif->kf_un.kf_sock.kf_sock_snd_sb_state =
 3574                                     so->so_snd.sb_state;
 3575                         }
 3576                 }
 3577                 break;
 3578         }
 3579         error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
 3580         if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
 3581                 bcopy(sa, &kif->kf_sa_local, sa->sa_len);
 3582                 free(sa, M_SONAME);
 3583         }
 3584         error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
 3585         if (error == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
 3586                 bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
 3587                 free(sa, M_SONAME);
 3588         }
 3589         strncpy(kif->kf_path, so->so_proto->pr_domain->dom_name,
 3590             sizeof(kif->kf_path));
 3591         return (0);
 3592 }
 3593 
 3594 static int
 3595 fill_pts_info(struct tty *tp, struct kinfo_file *kif)
 3596 {
 3597 
 3598         if (tp == NULL)
 3599                 return (1);
 3600         kif->kf_un.kf_pts.kf_pts_dev = tty_udev(tp);
 3601         strlcpy(kif->kf_path, tty_devname(tp), sizeof(kif->kf_path));
 3602         return (0);
 3603 }
 3604 
 3605 static int
 3606 fill_pipe_info(struct pipe *pi, struct kinfo_file *kif)
 3607 {
 3608 
 3609         if (pi == NULL)
 3610                 return (1);
 3611         kif->kf_un.kf_pipe.kf_pipe_addr = (uintptr_t)pi;
 3612         kif->kf_un.kf_pipe.kf_pipe_peer = (uintptr_t)pi->pipe_peer;
 3613         kif->kf_un.kf_pipe.kf_pipe_buffer_cnt = pi->pipe_buffer.cnt;
 3614         return (0);
 3615 }
 3616 
 3617 static int
 3618 fill_procdesc_info(struct procdesc *pdp, struct kinfo_file *kif)
 3619 {
 3620 
 3621         if (pdp == NULL)
 3622                 return (1);
 3623         kif->kf_un.kf_proc.kf_pid = pdp->pd_pid;
 3624         return (0);
 3625 }
 3626 
 3627 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD,
 3628     sysctl_kern_proc_filedesc, "Process filedesc entries");
 3629 
 3630 #ifdef DDB
 3631 /*
 3632  * For the purposes of debugging, generate a human-readable string for the
 3633  * file type.
 3634  */
 3635 static const char *
 3636 file_type_to_name(short type)
 3637 {
 3638 
 3639         switch (type) {
 3640         case 0:
 3641                 return ("zero");
 3642         case DTYPE_VNODE:
 3643                 return ("vnod");
 3644         case DTYPE_SOCKET:
 3645                 return ("sock");
 3646         case DTYPE_PIPE:
 3647                 return ("pipe");
 3648         case DTYPE_FIFO:
 3649                 return ("fifo");
 3650         case DTYPE_KQUEUE:
 3651                 return ("kque");
 3652         case DTYPE_CRYPTO:
 3653                 return ("crpt");
 3654         case DTYPE_MQUEUE:
 3655                 return ("mque");
 3656         case DTYPE_SHM:
 3657                 return ("shm");
 3658         case DTYPE_SEM:
 3659                 return ("ksem");
 3660         default:
 3661                 return ("unkn");
 3662         }
 3663 }
 3664 
 3665 /*
 3666  * For the purposes of debugging, identify a process (if any, perhaps one of
 3667  * many) that references the passed file in its file descriptor array. Return
 3668  * NULL if none.
 3669  */
 3670 static struct proc *
 3671 file_to_first_proc(struct file *fp)
 3672 {
 3673         struct filedesc *fdp;
 3674         struct proc *p;
 3675         int n;
 3676 
 3677         FOREACH_PROC_IN_SYSTEM(p) {
 3678                 if (p->p_state == PRS_NEW)
 3679                         continue;
 3680                 fdp = p->p_fd;
 3681                 if (fdp == NULL)
 3682                         continue;
 3683                 for (n = 0; n < fdp->fd_nfiles; n++) {
 3684                         if (fp == fdp->fd_ofiles[n])
 3685                                 return (p);
 3686                 }
 3687         }
 3688         return (NULL);
 3689 }
 3690 
 3691 static void
 3692 db_print_file(struct file *fp, int header)
 3693 {
 3694         struct proc *p;
 3695 
 3696         if (header)
 3697                 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n",
 3698                     "File", "Type", "Data", "Flag", "GCFl", "Count",
 3699                     "MCount", "Vnode", "FPID", "FCmd");
 3700         p = file_to_first_proc(fp);
 3701         db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp,
 3702             file_type_to_name(fp->f_type), fp->f_data, fp->f_flag,
 3703             0, fp->f_count, 0, fp->f_vnode,
 3704             p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
 3705 }
 3706 
 3707 DB_SHOW_COMMAND(file, db_show_file)
 3708 {
 3709         struct file *fp;
 3710 
 3711         if (!have_addr) {
 3712                 db_printf("usage: show file <addr>\n");
 3713                 return;
 3714         }
 3715         fp = (struct file *)addr;
 3716         db_print_file(fp, 1);
 3717 }
 3718 
 3719 DB_SHOW_COMMAND(files, db_show_files)
 3720 {
 3721         struct filedesc *fdp;
 3722         struct file *fp;
 3723         struct proc *p;
 3724         int header;
 3725         int n;
 3726 
 3727         header = 1;
 3728         FOREACH_PROC_IN_SYSTEM(p) {
 3729                 if (p->p_state == PRS_NEW)
 3730                         continue;
 3731                 if ((fdp = p->p_fd) == NULL)
 3732                         continue;
 3733                 for (n = 0; n < fdp->fd_nfiles; ++n) {
 3734                         if ((fp = fdp->fd_ofiles[n]) == NULL)
 3735                                 continue;
 3736                         db_print_file(fp, header);
 3737                         header = 0;
 3738                 }
 3739         }
 3740 }
 3741 #endif
 3742 
 3743 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
 3744     &maxfilesperproc, 0, "Maximum files allowed open per process");
 3745 
 3746 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
 3747     &maxfiles, 0, "Maximum number of files");
 3748 
 3749 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
 3750     __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files");
 3751 
 3752 /* ARGSUSED*/
 3753 static void
 3754 filelistinit(void *dummy)
 3755 {
 3756 
 3757         file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
 3758             NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 3759         mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
 3760         mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF);
 3761 }
 3762 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
 3763 
 3764 /*-------------------------------------------------------------------*/
 3765 
 3766 static int
 3767 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td)
 3768 {
 3769 
 3770         return (EBADF);
 3771 }
 3772 
 3773 static int
 3774 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td)
 3775 {
 3776 
 3777         return (EINVAL);
 3778 }
 3779 
 3780 static int
 3781 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td)
 3782 {
 3783 
 3784         return (EBADF);
 3785 }
 3786 
 3787 static int
 3788 badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td)
 3789 {
 3790 
 3791         return (0);
 3792 }
 3793 
 3794 static int
 3795 badfo_kqfilter(struct file *fp, struct knote *kn)
 3796 {
 3797 
 3798         return (EBADF);
 3799 }
 3800 
 3801 static int
 3802 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td)
 3803 {
 3804 
 3805         return (EBADF);
 3806 }
 3807 
 3808 static int
 3809 badfo_close(struct file *fp, struct thread *td)
 3810 {
 3811 
 3812         return (EBADF);
 3813 }
 3814 
 3815 static int
 3816 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
 3817     struct thread *td)
 3818 {
 3819 
 3820         return (EBADF);
 3821 }
 3822 
 3823 static int
 3824 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
 3825     struct thread *td)
 3826 {
 3827 
 3828         return (EBADF);
 3829 }
 3830 
 3831 struct fileops badfileops = {
 3832         .fo_read = badfo_readwrite,
 3833         .fo_write = badfo_readwrite,
 3834         .fo_truncate = badfo_truncate,
 3835         .fo_ioctl = badfo_ioctl,
 3836         .fo_poll = badfo_poll,
 3837         .fo_kqfilter = badfo_kqfilter,
 3838         .fo_stat = badfo_stat,
 3839         .fo_close = badfo_close,
 3840         .fo_chmod = badfo_chmod,
 3841         .fo_chown = badfo_chown,
 3842 };
 3843 
 3844 int
 3845 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
 3846     struct thread *td)
 3847 {
 3848 
 3849         return (EINVAL);
 3850 }
 3851 
 3852 int
 3853 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
 3854     struct thread *td)
 3855 {
 3856 
 3857         return (EINVAL);
 3858 }
 3859 
 3860 /*-------------------------------------------------------------------*/
 3861 
 3862 /*
 3863  * File Descriptor pseudo-device driver (/dev/fd/).
 3864  *
 3865  * Opening minor device N dup()s the file (if any) connected to file
 3866  * descriptor N belonging to the calling process.  Note that this driver
 3867  * consists of only the ``open()'' routine, because all subsequent
 3868  * references to this file will be direct to the other driver.
 3869  *
 3870  * XXX: we could give this one a cloning event handler if necessary.
 3871  */
 3872 
 3873 /* ARGSUSED */
 3874 static int
 3875 fdopen(struct cdev *dev, int mode, int type, struct thread *td)
 3876 {
 3877 
 3878         /*
 3879          * XXX Kludge: set curthread->td_dupfd to contain the value of the
 3880          * the file descriptor being sought for duplication. The error
 3881          * return ensures that the vnode for this device will be released
 3882          * by vn_open. Open will detect this special error and take the
 3883          * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
 3884          * will simply report the error.
 3885          */
 3886         td->td_dupfd = dev2unit(dev);
 3887         return (ENODEV);
 3888 }
 3889 
 3890 static struct cdevsw fildesc_cdevsw = {
 3891         .d_version =    D_VERSION,
 3892         .d_open =       fdopen,
 3893         .d_name =       "FD",
 3894 };
 3895 
 3896 static void
 3897 fildesc_drvinit(void *unused)
 3898 {
 3899         struct cdev *dev;
 3900 
 3901         dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
 3902             UID_ROOT, GID_WHEEL, 0666, "fd/0");
 3903         make_dev_alias(dev, "stdin");
 3904         dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
 3905             UID_ROOT, GID_WHEEL, 0666, "fd/1");
 3906         make_dev_alias(dev, "stdout");
 3907         dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
 3908             UID_ROOT, GID_WHEEL, 0666, "fd/2");
 3909         make_dev_alias(dev, "stderr");
 3910 }
 3911 
 3912 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);

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