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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1991, 1993
    3  *      The Regents of the University of California.
    4  * Copyright (c) 2004-2009 Robert N. M. Watson
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 4. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
   32  */
   33 
   34 /*
   35  * UNIX Domain (Local) Sockets
   36  *
   37  * This is an implementation of UNIX (local) domain sockets.  Each socket has
   38  * an associated struct unpcb (UNIX protocol control block).  Stream sockets
   39  * may be connected to 0 or 1 other socket.  Datagram sockets may be
   40  * connected to 0, 1, or many other sockets.  Sockets may be created and
   41  * connected in pairs (socketpair(2)), or bound/connected to using the file
   42  * system name space.  For most purposes, only the receive socket buffer is
   43  * used, as sending on one socket delivers directly to the receive socket
   44  * buffer of a second socket.
   45  *
   46  * The implementation is substantially complicated by the fact that
   47  * "ancillary data", such as file descriptors or credentials, may be passed
   48  * across UNIX domain sockets.  The potential for passing UNIX domain sockets
   49  * over other UNIX domain sockets requires the implementation of a simple
   50  * garbage collector to find and tear down cycles of disconnected sockets.
   51  *
   52  * TODO:
   53  *      SEQPACKET, RDM
   54  *      rethink name space problems
   55  *      need a proper out-of-band
   56  */
   57 
   58 #include <sys/cdefs.h>
   59 __FBSDID("$FreeBSD: releng/8.0/sys/kern/uipc_usrreq.c 196019 2009-08-01 19:26:27Z rwatson $");
   60 
   61 #include "opt_ddb.h"
   62 
   63 #include <sys/param.h>
   64 #include <sys/domain.h>
   65 #include <sys/fcntl.h>
   66 #include <sys/malloc.h>         /* XXX must be before <sys/file.h> */
   67 #include <sys/eventhandler.h>
   68 #include <sys/file.h>
   69 #include <sys/filedesc.h>
   70 #include <sys/kernel.h>
   71 #include <sys/lock.h>
   72 #include <sys/mbuf.h>
   73 #include <sys/mount.h>
   74 #include <sys/mutex.h>
   75 #include <sys/namei.h>
   76 #include <sys/proc.h>
   77 #include <sys/protosw.h>
   78 #include <sys/resourcevar.h>
   79 #include <sys/rwlock.h>
   80 #include <sys/socket.h>
   81 #include <sys/socketvar.h>
   82 #include <sys/signalvar.h>
   83 #include <sys/stat.h>
   84 #include <sys/sx.h>
   85 #include <sys/sysctl.h>
   86 #include <sys/systm.h>
   87 #include <sys/taskqueue.h>
   88 #include <sys/un.h>
   89 #include <sys/unpcb.h>
   90 #include <sys/vnode.h>
   91 
   92 #include <net/vnet.h>
   93 
   94 #ifdef DDB
   95 #include <ddb/ddb.h>
   96 #endif
   97 
   98 #include <security/mac/mac_framework.h>
   99 
  100 #include <vm/uma.h>
  101 
  102 /*
  103  * Locking key:
  104  * (l)  Locked using list lock
  105  * (g)  Locked using linkage lock
  106  */
  107 
  108 static uma_zone_t       unp_zone;
  109 static unp_gen_t        unp_gencnt;     /* (l) */
  110 static u_int            unp_count;      /* (l) Count of local sockets. */
  111 static ino_t            unp_ino;        /* Prototype for fake inode numbers. */
  112 static int              unp_rights;     /* (g) File descriptors in flight. */
  113 static struct unp_head  unp_shead;      /* (l) List of stream sockets. */
  114 static struct unp_head  unp_dhead;      /* (l) List of datagram sockets. */
  115 
  116 static const struct sockaddr    sun_noname = { sizeof(sun_noname), AF_LOCAL };
  117 
  118 /*
  119  * Garbage collection of cyclic file descriptor/socket references occurs
  120  * asynchronously in a taskqueue context in order to avoid recursion and
  121  * reentrance in the UNIX domain socket, file descriptor, and socket layer
  122  * code.  See unp_gc() for a full description.
  123  */
  124 static struct task      unp_gc_task;
  125 
  126 /*
  127  * Both send and receive buffers are allocated PIPSIZ bytes of buffering for
  128  * stream sockets, although the total for sender and receiver is actually
  129  * only PIPSIZ.
  130  *
  131  * Datagram sockets really use the sendspace as the maximum datagram size,
  132  * and don't really want to reserve the sendspace.  Their recvspace should be
  133  * large enough for at least one max-size datagram plus address.
  134  */
  135 #ifndef PIPSIZ
  136 #define PIPSIZ  8192
  137 #endif
  138 static u_long   unpst_sendspace = PIPSIZ;
  139 static u_long   unpst_recvspace = PIPSIZ;
  140 static u_long   unpdg_sendspace = 2*1024;       /* really max datagram size */
  141 static u_long   unpdg_recvspace = 4*1024;
  142 
  143 SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain");
  144 SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM");
  145 SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM");
  146 
  147 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
  148            &unpst_sendspace, 0, "Default stream send space.");
  149 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
  150            &unpst_recvspace, 0, "Default stream receive space.");
  151 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
  152            &unpdg_sendspace, 0, "Default datagram send space.");
  153 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
  154            &unpdg_recvspace, 0, "Default datagram receive space.");
  155 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 
  156     "File descriptors in flight.");
  157 
  158 /*-
  159  * Locking and synchronization:
  160  *
  161  * Three types of locks exit in the local domain socket implementation: a
  162  * global list mutex, a global linkage rwlock, and per-unpcb mutexes.  Of the
  163  * global locks, the list lock protects the socket count, global generation
  164  * number, and stream/datagram global lists.  The linkage lock protects the
  165  * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be
  166  * held exclusively over the acquisition of multiple unpcb locks to prevent
  167  * deadlock.
  168  *
  169  * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
  170  * allocated in pru_attach() and freed in pru_detach().  The validity of that
  171  * pointer is an invariant, so no lock is required to dereference the so_pcb
  172  * pointer if a valid socket reference is held by the caller.  In practice,
  173  * this is always true during operations performed on a socket.  Each unpcb
  174  * has a back-pointer to its socket, unp_socket, which will be stable under
  175  * the same circumstances.
  176  *
  177  * This pointer may only be safely dereferenced as long as a valid reference
  178  * to the unpcb is held.  Typically, this reference will be from the socket,
  179  * or from another unpcb when the referring unpcb's lock is held (in order
  180  * that the reference not be invalidated during use).  For example, to follow
  181  * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
  182  * as unp_socket remains valid as long as the reference to unp_conn is valid.
  183  *
  184  * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx.  Individual
  185  * atomic reads without the lock may be performed "lockless", but more
  186  * complex reads and read-modify-writes require the mutex to be held.  No
  187  * lock order is defined between unpcb locks -- multiple unpcb locks may be
  188  * acquired at the same time only when holding the linkage rwlock
  189  * exclusively, which prevents deadlocks.
  190  *
  191  * Blocking with UNIX domain sockets is a tricky issue: unlike most network
  192  * protocols, bind() is a non-atomic operation, and connect() requires
  193  * potential sleeping in the protocol, due to potentially waiting on local or
  194  * distributed file systems.  We try to separate "lookup" operations, which
  195  * may sleep, and the IPC operations themselves, which typically can occur
  196  * with relative atomicity as locks can be held over the entire operation.
  197  *
  198  * Another tricky issue is simultaneous multi-threaded or multi-process
  199  * access to a single UNIX domain socket.  These are handled by the flags
  200  * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
  201  * binding, both of which involve dropping UNIX domain socket locks in order
  202  * to perform namei() and other file system operations.
  203  */
  204 static struct rwlock    unp_link_rwlock;
  205 static struct mtx       unp_list_lock;
  206 
  207 #define UNP_LINK_LOCK_INIT()            rw_init(&unp_link_rwlock,       \
  208                                             "unp_link_rwlock")
  209 
  210 #define UNP_LINK_LOCK_ASSERT()  rw_assert(&unp_link_rwlock,     \
  211                                             RA_LOCKED)
  212 #define UNP_LINK_UNLOCK_ASSERT()        rw_assert(&unp_link_rwlock,     \
  213                                             RA_UNLOCKED)
  214 
  215 #define UNP_LINK_RLOCK()                rw_rlock(&unp_link_rwlock)
  216 #define UNP_LINK_RUNLOCK()              rw_runlock(&unp_link_rwlock)
  217 #define UNP_LINK_WLOCK()                rw_wlock(&unp_link_rwlock)
  218 #define UNP_LINK_WUNLOCK()              rw_wunlock(&unp_link_rwlock)
  219 #define UNP_LINK_WLOCK_ASSERT()         rw_assert(&unp_link_rwlock,     \
  220                                             RA_WLOCKED)
  221 
  222 #define UNP_LIST_LOCK_INIT()            mtx_init(&unp_list_lock,        \
  223                                             "unp_list_lock", NULL, MTX_DEF)
  224 #define UNP_LIST_LOCK()                 mtx_lock(&unp_list_lock)
  225 #define UNP_LIST_UNLOCK()               mtx_unlock(&unp_list_lock)
  226 
  227 #define UNP_PCB_LOCK_INIT(unp)          mtx_init(&(unp)->unp_mtx,       \
  228                                             "unp_mtx", "unp_mtx",       \
  229                                             MTX_DUPOK|MTX_DEF|MTX_RECURSE)
  230 #define UNP_PCB_LOCK_DESTROY(unp)       mtx_destroy(&(unp)->unp_mtx)
  231 #define UNP_PCB_LOCK(unp)               mtx_lock(&(unp)->unp_mtx)
  232 #define UNP_PCB_UNLOCK(unp)             mtx_unlock(&(unp)->unp_mtx)
  233 #define UNP_PCB_LOCK_ASSERT(unp)        mtx_assert(&(unp)->unp_mtx, MA_OWNED)
  234 
  235 static int      uipc_connect2(struct socket *, struct socket *);
  236 static int      uipc_ctloutput(struct socket *, struct sockopt *);
  237 static int      unp_connect(struct socket *, struct sockaddr *,
  238                     struct thread *);
  239 static int      unp_connect2(struct socket *so, struct socket *so2, int);
  240 static void     unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
  241 static void     unp_dispose(struct mbuf *);
  242 static void     unp_shutdown(struct unpcb *);
  243 static void     unp_drop(struct unpcb *, int);
  244 static void     unp_gc(__unused void *, int);
  245 static void     unp_scan(struct mbuf *, void (*)(struct file *));
  246 static void     unp_discard(struct file *);
  247 static void     unp_freerights(struct file **, int);
  248 static void     unp_init(void);
  249 static int      unp_internalize(struct mbuf **, struct thread *);
  250 static void     unp_internalize_fp(struct file *);
  251 static int      unp_externalize(struct mbuf *, struct mbuf **);
  252 static void     unp_externalize_fp(struct file *);
  253 static struct mbuf      *unp_addsockcred(struct thread *, struct mbuf *);
  254 
  255 /*
  256  * Definitions of protocols supported in the LOCAL domain.
  257  */
  258 static struct domain localdomain;
  259 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
  260 static struct protosw localsw[] = {
  261 {
  262         .pr_type =              SOCK_STREAM,
  263         .pr_domain =            &localdomain,
  264         .pr_flags =             PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
  265         .pr_ctloutput =         &uipc_ctloutput,
  266         .pr_usrreqs =           &uipc_usrreqs_stream
  267 },
  268 {
  269         .pr_type =              SOCK_DGRAM,
  270         .pr_domain =            &localdomain,
  271         .pr_flags =             PR_ATOMIC|PR_ADDR|PR_RIGHTS,
  272         .pr_usrreqs =           &uipc_usrreqs_dgram
  273 },
  274 };
  275 
  276 static struct domain localdomain = {
  277         .dom_family =           AF_LOCAL,
  278         .dom_name =             "local",
  279         .dom_init =             unp_init,
  280         .dom_externalize =      unp_externalize,
  281         .dom_dispose =          unp_dispose,
  282         .dom_protosw =          localsw,
  283         .dom_protoswNPROTOSW =  &localsw[sizeof(localsw)/sizeof(localsw[0])]
  284 };
  285 DOMAIN_SET(local);
  286 
  287 static void
  288 uipc_abort(struct socket *so)
  289 {
  290         struct unpcb *unp, *unp2;
  291 
  292         unp = sotounpcb(so);
  293         KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
  294 
  295         UNP_LINK_WLOCK();
  296         UNP_PCB_LOCK(unp);
  297         unp2 = unp->unp_conn;
  298         if (unp2 != NULL) {
  299                 UNP_PCB_LOCK(unp2);
  300                 unp_drop(unp2, ECONNABORTED);
  301                 UNP_PCB_UNLOCK(unp2);
  302         }
  303         UNP_PCB_UNLOCK(unp);
  304         UNP_LINK_WUNLOCK();
  305 }
  306 
  307 static int
  308 uipc_accept(struct socket *so, struct sockaddr **nam)
  309 {
  310         struct unpcb *unp, *unp2;
  311         const struct sockaddr *sa;
  312 
  313         /*
  314          * Pass back name of connected socket, if it was bound and we are
  315          * still connected (our peer may have closed already!).
  316          */
  317         unp = sotounpcb(so);
  318         KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
  319 
  320         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
  321         UNP_LINK_RLOCK();
  322         unp2 = unp->unp_conn;
  323         if (unp2 != NULL && unp2->unp_addr != NULL) {
  324                 UNP_PCB_LOCK(unp2);
  325                 sa = (struct sockaddr *) unp2->unp_addr;
  326                 bcopy(sa, *nam, sa->sa_len);
  327                 UNP_PCB_UNLOCK(unp2);
  328         } else {
  329                 sa = &sun_noname;
  330                 bcopy(sa, *nam, sa->sa_len);
  331         }
  332         UNP_LINK_RUNLOCK();
  333         return (0);
  334 }
  335 
  336 static int
  337 uipc_attach(struct socket *so, int proto, struct thread *td)
  338 {
  339         u_long sendspace, recvspace;
  340         struct unpcb *unp;
  341         int error;
  342 
  343         KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
  344         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
  345                 switch (so->so_type) {
  346                 case SOCK_STREAM:
  347                         sendspace = unpst_sendspace;
  348                         recvspace = unpst_recvspace;
  349                         break;
  350 
  351                 case SOCK_DGRAM:
  352                         sendspace = unpdg_sendspace;
  353                         recvspace = unpdg_recvspace;
  354                         break;
  355 
  356                 default:
  357                         panic("uipc_attach");
  358                 }
  359                 error = soreserve(so, sendspace, recvspace);
  360                 if (error)
  361                         return (error);
  362         }
  363         unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
  364         if (unp == NULL)
  365                 return (ENOBUFS);
  366         LIST_INIT(&unp->unp_refs);
  367         UNP_PCB_LOCK_INIT(unp);
  368         unp->unp_socket = so;
  369         so->so_pcb = unp;
  370         unp->unp_refcount = 1;
  371 
  372         UNP_LIST_LOCK();
  373         unp->unp_gencnt = ++unp_gencnt;
  374         unp_count++;
  375         LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead,
  376             unp, unp_link);
  377         UNP_LIST_UNLOCK();
  378 
  379         return (0);
  380 }
  381 
  382 static int
  383 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  384 {
  385         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
  386         struct vattr vattr;
  387         int error, namelen, vfslocked;
  388         struct nameidata nd;
  389         struct unpcb *unp;
  390         struct vnode *vp;
  391         struct mount *mp;
  392         char *buf;
  393 
  394         unp = sotounpcb(so);
  395         KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
  396 
  397         namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
  398         if (namelen <= 0)
  399                 return (EINVAL);
  400 
  401         /*
  402          * We don't allow simultaneous bind() calls on a single UNIX domain
  403          * socket, so flag in-progress operations, and return an error if an
  404          * operation is already in progress.
  405          *
  406          * Historically, we have not allowed a socket to be rebound, so this
  407          * also returns an error.  Not allowing re-binding simplifies the
  408          * implementation and avoids a great many possible failure modes.
  409          */
  410         UNP_PCB_LOCK(unp);
  411         if (unp->unp_vnode != NULL) {
  412                 UNP_PCB_UNLOCK(unp);
  413                 return (EINVAL);
  414         }
  415         if (unp->unp_flags & UNP_BINDING) {
  416                 UNP_PCB_UNLOCK(unp);
  417                 return (EALREADY);
  418         }
  419         unp->unp_flags |= UNP_BINDING;
  420         UNP_PCB_UNLOCK(unp);
  421 
  422         buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
  423         bcopy(soun->sun_path, buf, namelen);
  424         buf[namelen] = 0;
  425 
  426 restart:
  427         vfslocked = 0;
  428         NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME,
  429             UIO_SYSSPACE, buf, td);
  430 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
  431         error = namei(&nd);
  432         if (error)
  433                 goto error;
  434         vp = nd.ni_vp;
  435         vfslocked = NDHASGIANT(&nd);
  436         if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
  437                 NDFREE(&nd, NDF_ONLY_PNBUF);
  438                 if (nd.ni_dvp == vp)
  439                         vrele(nd.ni_dvp);
  440                 else
  441                         vput(nd.ni_dvp);
  442                 if (vp != NULL) {
  443                         vrele(vp);
  444                         error = EADDRINUSE;
  445                         goto error;
  446                 }
  447                 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
  448                 if (error)
  449                         goto error;
  450                 VFS_UNLOCK_GIANT(vfslocked);
  451                 goto restart;
  452         }
  453         VATTR_NULL(&vattr);
  454         vattr.va_type = VSOCK;
  455         vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
  456 #ifdef MAC
  457         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
  458             &vattr);
  459 #endif
  460         if (error == 0)
  461                 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
  462         NDFREE(&nd, NDF_ONLY_PNBUF);
  463         vput(nd.ni_dvp);
  464         if (error) {
  465                 vn_finished_write(mp);
  466                 goto error;
  467         }
  468         vp = nd.ni_vp;
  469         ASSERT_VOP_ELOCKED(vp, "uipc_bind");
  470         soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
  471 
  472         UNP_LINK_WLOCK();
  473         UNP_PCB_LOCK(unp);
  474         vp->v_socket = unp->unp_socket;
  475         unp->unp_vnode = vp;
  476         unp->unp_addr = soun;
  477         unp->unp_flags &= ~UNP_BINDING;
  478         UNP_PCB_UNLOCK(unp);
  479         UNP_LINK_WUNLOCK();
  480         VOP_UNLOCK(vp, 0);
  481         vn_finished_write(mp);
  482         VFS_UNLOCK_GIANT(vfslocked);
  483         free(buf, M_TEMP);
  484         return (0);
  485 
  486 error:
  487         VFS_UNLOCK_GIANT(vfslocked);
  488         UNP_PCB_LOCK(unp);
  489         unp->unp_flags &= ~UNP_BINDING;
  490         UNP_PCB_UNLOCK(unp);
  491         free(buf, M_TEMP);
  492         return (error);
  493 }
  494 
  495 static int
  496 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  497 {
  498         int error;
  499 
  500         KASSERT(td == curthread, ("uipc_connect: td != curthread"));
  501         UNP_LINK_WLOCK();
  502         error = unp_connect(so, nam, td);
  503         UNP_LINK_WUNLOCK();
  504         return (error);
  505 }
  506 
  507 static void
  508 uipc_close(struct socket *so)
  509 {
  510         struct unpcb *unp, *unp2;
  511 
  512         unp = sotounpcb(so);
  513         KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
  514 
  515         UNP_LINK_WLOCK();
  516         UNP_PCB_LOCK(unp);
  517         unp2 = unp->unp_conn;
  518         if (unp2 != NULL) {
  519                 UNP_PCB_LOCK(unp2);
  520                 unp_disconnect(unp, unp2);
  521                 UNP_PCB_UNLOCK(unp2);
  522         }
  523         UNP_PCB_UNLOCK(unp);
  524         UNP_LINK_WUNLOCK();
  525 }
  526 
  527 static int
  528 uipc_connect2(struct socket *so1, struct socket *so2)
  529 {
  530         struct unpcb *unp, *unp2;
  531         int error;
  532 
  533         UNP_LINK_WLOCK();
  534         unp = so1->so_pcb;
  535         KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
  536         UNP_PCB_LOCK(unp);
  537         unp2 = so2->so_pcb;
  538         KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
  539         UNP_PCB_LOCK(unp2);
  540         error = unp_connect2(so1, so2, PRU_CONNECT2);
  541         UNP_PCB_UNLOCK(unp2);
  542         UNP_PCB_UNLOCK(unp);
  543         UNP_LINK_WUNLOCK();
  544         return (error);
  545 }
  546 
  547 static void
  548 uipc_detach(struct socket *so)
  549 {
  550         struct unpcb *unp, *unp2;
  551         struct sockaddr_un *saved_unp_addr;
  552         struct vnode *vp;
  553         int freeunp, local_unp_rights;
  554 
  555         unp = sotounpcb(so);
  556         KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
  557 
  558         UNP_LINK_WLOCK();
  559         UNP_LIST_LOCK();
  560         UNP_PCB_LOCK(unp);
  561         LIST_REMOVE(unp, unp_link);
  562         unp->unp_gencnt = ++unp_gencnt;
  563         --unp_count;
  564         UNP_LIST_UNLOCK();
  565 
  566         /*
  567          * XXXRW: Should assert vp->v_socket == so.
  568          */
  569         if ((vp = unp->unp_vnode) != NULL) {
  570                 unp->unp_vnode->v_socket = NULL;
  571                 unp->unp_vnode = NULL;
  572         }
  573         unp2 = unp->unp_conn;
  574         if (unp2 != NULL) {
  575                 UNP_PCB_LOCK(unp2);
  576                 unp_disconnect(unp, unp2);
  577                 UNP_PCB_UNLOCK(unp2);
  578         }
  579 
  580         /*
  581          * We hold the linkage lock exclusively, so it's OK to acquire
  582          * multiple pcb locks at a time.
  583          */
  584         while (!LIST_EMPTY(&unp->unp_refs)) {
  585                 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
  586 
  587                 UNP_PCB_LOCK(ref);
  588                 unp_drop(ref, ECONNRESET);
  589                 UNP_PCB_UNLOCK(ref);
  590         }
  591         local_unp_rights = unp_rights;
  592         UNP_LINK_WUNLOCK();
  593         unp->unp_socket->so_pcb = NULL;
  594         saved_unp_addr = unp->unp_addr;
  595         unp->unp_addr = NULL;
  596         unp->unp_refcount--;
  597         freeunp = (unp->unp_refcount == 0);
  598         if (saved_unp_addr != NULL)
  599                 free(saved_unp_addr, M_SONAME);
  600         if (freeunp) {
  601                 UNP_PCB_LOCK_DESTROY(unp);
  602                 uma_zfree(unp_zone, unp);
  603         } else
  604                 UNP_PCB_UNLOCK(unp);
  605         if (vp) {
  606                 int vfslocked;
  607 
  608                 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
  609                 vrele(vp);
  610                 VFS_UNLOCK_GIANT(vfslocked);
  611         }
  612         if (local_unp_rights)
  613                 taskqueue_enqueue(taskqueue_thread, &unp_gc_task);
  614 }
  615 
  616 static int
  617 uipc_disconnect(struct socket *so)
  618 {
  619         struct unpcb *unp, *unp2;
  620 
  621         unp = sotounpcb(so);
  622         KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
  623 
  624         UNP_LINK_WLOCK();
  625         UNP_PCB_LOCK(unp);
  626         unp2 = unp->unp_conn;
  627         if (unp2 != NULL) {
  628                 UNP_PCB_LOCK(unp2);
  629                 unp_disconnect(unp, unp2);
  630                 UNP_PCB_UNLOCK(unp2);
  631         }
  632         UNP_PCB_UNLOCK(unp);
  633         UNP_LINK_WUNLOCK();
  634         return (0);
  635 }
  636 
  637 static int
  638 uipc_listen(struct socket *so, int backlog, struct thread *td)
  639 {
  640         struct unpcb *unp;
  641         int error;
  642 
  643         unp = sotounpcb(so);
  644         KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
  645 
  646         UNP_PCB_LOCK(unp);
  647         if (unp->unp_vnode == NULL) {
  648                 UNP_PCB_UNLOCK(unp);
  649                 return (EINVAL);
  650         }
  651 
  652         SOCK_LOCK(so);
  653         error = solisten_proto_check(so);
  654         if (error == 0) {
  655                 cru2x(td->td_ucred, &unp->unp_peercred);
  656                 unp->unp_flags |= UNP_HAVEPCCACHED;
  657                 solisten_proto(so, backlog);
  658         }
  659         SOCK_UNLOCK(so);
  660         UNP_PCB_UNLOCK(unp);
  661         return (error);
  662 }
  663 
  664 static int
  665 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
  666 {
  667         struct unpcb *unp, *unp2;
  668         const struct sockaddr *sa;
  669 
  670         unp = sotounpcb(so);
  671         KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
  672 
  673         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
  674         UNP_LINK_RLOCK();
  675         /*
  676          * XXX: It seems that this test always fails even when connection is
  677          * established.  So, this else clause is added as workaround to
  678          * return PF_LOCAL sockaddr.
  679          */
  680         unp2 = unp->unp_conn;
  681         if (unp2 != NULL) {
  682                 UNP_PCB_LOCK(unp2);
  683                 if (unp2->unp_addr != NULL)
  684                         sa = (struct sockaddr *) unp2->unp_addr;
  685                 else
  686                         sa = &sun_noname;
  687                 bcopy(sa, *nam, sa->sa_len);
  688                 UNP_PCB_UNLOCK(unp2);
  689         } else {
  690                 sa = &sun_noname;
  691                 bcopy(sa, *nam, sa->sa_len);
  692         }
  693         UNP_LINK_RUNLOCK();
  694         return (0);
  695 }
  696 
  697 static int
  698 uipc_rcvd(struct socket *so, int flags)
  699 {
  700         struct unpcb *unp, *unp2;
  701         struct socket *so2;
  702         u_int mbcnt, sbcc;
  703         u_long newhiwat;
  704 
  705         unp = sotounpcb(so);
  706         KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL"));
  707 
  708         if (so->so_type == SOCK_DGRAM)
  709                 panic("uipc_rcvd DGRAM?");
  710 
  711         if (so->so_type != SOCK_STREAM)
  712                 panic("uipc_rcvd unknown socktype");
  713 
  714         /*
  715          * Adjust backpressure on sender and wakeup any waiting to write.
  716          *
  717          * The unp lock is acquired to maintain the validity of the unp_conn
  718          * pointer; no lock on unp2 is required as unp2->unp_socket will be
  719          * static as long as we don't permit unp2 to disconnect from unp,
  720          * which is prevented by the lock on unp.  We cache values from
  721          * so_rcv to avoid holding the so_rcv lock over the entire
  722          * transaction on the remote so_snd.
  723          */
  724         SOCKBUF_LOCK(&so->so_rcv);
  725         mbcnt = so->so_rcv.sb_mbcnt;
  726         sbcc = so->so_rcv.sb_cc;
  727         SOCKBUF_UNLOCK(&so->so_rcv);
  728         UNP_PCB_LOCK(unp);
  729         unp2 = unp->unp_conn;
  730         if (unp2 == NULL) {
  731                 UNP_PCB_UNLOCK(unp);
  732                 return (0);
  733         }
  734         so2 = unp2->unp_socket;
  735         SOCKBUF_LOCK(&so2->so_snd);
  736         so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt;
  737         newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc;
  738         (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat,
  739             newhiwat, RLIM_INFINITY);
  740         sowwakeup_locked(so2);
  741         unp->unp_mbcnt = mbcnt;
  742         unp->unp_cc = sbcc;
  743         UNP_PCB_UNLOCK(unp);
  744         return (0);
  745 }
  746 
  747 static int
  748 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
  749     struct mbuf *control, struct thread *td)
  750 {
  751         struct unpcb *unp, *unp2;
  752         struct socket *so2;
  753         u_int mbcnt_delta, sbcc;
  754         u_long newhiwat;
  755         int error = 0;
  756 
  757         unp = sotounpcb(so);
  758         KASSERT(unp != NULL, ("uipc_send: unp == NULL"));
  759 
  760         if (flags & PRUS_OOB) {
  761                 error = EOPNOTSUPP;
  762                 goto release;
  763         }
  764         if (control != NULL && (error = unp_internalize(&control, td)))
  765                 goto release;
  766         if ((nam != NULL) || (flags & PRUS_EOF))
  767                 UNP_LINK_WLOCK();
  768         else
  769                 UNP_LINK_RLOCK();
  770         switch (so->so_type) {
  771         case SOCK_DGRAM:
  772         {
  773                 const struct sockaddr *from;
  774 
  775                 unp2 = unp->unp_conn;
  776                 if (nam != NULL) {
  777                         UNP_LINK_WLOCK_ASSERT();
  778                         if (unp2 != NULL) {
  779                                 error = EISCONN;
  780                                 break;
  781                         }
  782                         error = unp_connect(so, nam, td);
  783                         if (error)
  784                                 break;
  785                         unp2 = unp->unp_conn;
  786                 }
  787 
  788                 /*
  789                  * Because connect() and send() are non-atomic in a sendto()
  790                  * with a target address, it's possible that the socket will
  791                  * have disconnected before the send() can run.  In that case
  792                  * return the slightly counter-intuitive but otherwise
  793                  * correct error that the socket is not connected.
  794                  */
  795                 if (unp2 == NULL) {
  796                         error = ENOTCONN;
  797                         break;
  798                 }
  799                 /* Lockless read. */
  800                 if (unp2->unp_flags & UNP_WANTCRED)
  801                         control = unp_addsockcred(td, control);
  802                 UNP_PCB_LOCK(unp);
  803                 if (unp->unp_addr != NULL)
  804                         from = (struct sockaddr *)unp->unp_addr;
  805                 else
  806                         from = &sun_noname;
  807                 so2 = unp2->unp_socket;
  808                 SOCKBUF_LOCK(&so2->so_rcv);
  809                 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) {
  810                         sorwakeup_locked(so2);
  811                         m = NULL;
  812                         control = NULL;
  813                 } else {
  814                         SOCKBUF_UNLOCK(&so2->so_rcv);
  815                         error = ENOBUFS;
  816                 }
  817                 if (nam != NULL) {
  818                         UNP_LINK_WLOCK_ASSERT();
  819                         UNP_PCB_LOCK(unp2);
  820                         unp_disconnect(unp, unp2);
  821                         UNP_PCB_UNLOCK(unp2);
  822                 }
  823                 UNP_PCB_UNLOCK(unp);
  824                 break;
  825         }
  826 
  827         case SOCK_STREAM:
  828                 if ((so->so_state & SS_ISCONNECTED) == 0) {
  829                         if (nam != NULL) {
  830                                 UNP_LINK_WLOCK_ASSERT();
  831                                 error = unp_connect(so, nam, td);
  832                                 if (error)
  833                                         break;  /* XXX */
  834                         } else {
  835                                 error = ENOTCONN;
  836                                 break;
  837                         }
  838                 }
  839 
  840                 /* Lockless read. */
  841                 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
  842                         error = EPIPE;
  843                         break;
  844                 }
  845 
  846                 /*
  847                  * Because connect() and send() are non-atomic in a sendto()
  848                  * with a target address, it's possible that the socket will
  849                  * have disconnected before the send() can run.  In that case
  850                  * return the slightly counter-intuitive but otherwise
  851                  * correct error that the socket is not connected.
  852                  *
  853                  * Locking here must be done carefully: the linkage lock
  854                  * prevents interconnections between unpcbs from changing, so
  855                  * we can traverse from unp to unp2 without acquiring unp's
  856                  * lock.  Socket buffer locks follow unpcb locks, so we can
  857                  * acquire both remote and lock socket buffer locks.
  858                  */
  859                 unp2 = unp->unp_conn;
  860                 if (unp2 == NULL) {
  861                         error = ENOTCONN;
  862                         break;
  863                 }
  864                 so2 = unp2->unp_socket;
  865                 UNP_PCB_LOCK(unp2);
  866                 SOCKBUF_LOCK(&so2->so_rcv);
  867                 if (unp2->unp_flags & UNP_WANTCRED) {
  868                         /*
  869                          * Credentials are passed only once on SOCK_STREAM.
  870                          */
  871                         unp2->unp_flags &= ~UNP_WANTCRED;
  872                         control = unp_addsockcred(td, control);
  873                 }
  874                 /*
  875                  * Send to paired receive port, and then reduce send buffer
  876                  * hiwater marks to maintain backpressure.  Wake up readers.
  877                  */
  878                 if (control != NULL) {
  879                         if (sbappendcontrol_locked(&so2->so_rcv, m, control))
  880                                 control = NULL;
  881                 } else
  882                         sbappend_locked(&so2->so_rcv, m);
  883                 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt;
  884                 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt;
  885                 sbcc = so2->so_rcv.sb_cc;
  886                 sorwakeup_locked(so2);
  887 
  888                 SOCKBUF_LOCK(&so->so_snd);
  889                 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc);
  890                 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat,
  891                     newhiwat, RLIM_INFINITY);
  892                 so->so_snd.sb_mbmax -= mbcnt_delta;
  893                 SOCKBUF_UNLOCK(&so->so_snd);
  894                 unp2->unp_cc = sbcc;
  895                 UNP_PCB_UNLOCK(unp2);
  896                 m = NULL;
  897                 break;
  898 
  899         default:
  900                 panic("uipc_send unknown socktype");
  901         }
  902 
  903         /*
  904          * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
  905          */
  906         if (flags & PRUS_EOF) {
  907                 UNP_PCB_LOCK(unp);
  908                 socantsendmore(so);
  909                 unp_shutdown(unp);
  910                 UNP_PCB_UNLOCK(unp);
  911         }
  912 
  913         if ((nam != NULL) || (flags & PRUS_EOF))
  914                 UNP_LINK_WUNLOCK();
  915         else
  916                 UNP_LINK_RUNLOCK();
  917 
  918         if (control != NULL && error != 0)
  919                 unp_dispose(control);
  920 
  921 release:
  922         if (control != NULL)
  923                 m_freem(control);
  924         if (m != NULL)
  925                 m_freem(m);
  926         return (error);
  927 }
  928 
  929 static int
  930 uipc_sense(struct socket *so, struct stat *sb)
  931 {
  932         struct unpcb *unp, *unp2;
  933         struct socket *so2;
  934 
  935         unp = sotounpcb(so);
  936         KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
  937 
  938         sb->st_blksize = so->so_snd.sb_hiwat;
  939         UNP_LINK_RLOCK();
  940         UNP_PCB_LOCK(unp);
  941         unp2 = unp->unp_conn;
  942         if (so->so_type == SOCK_STREAM && unp2 != NULL) {
  943                 so2 = unp2->unp_socket;
  944                 sb->st_blksize += so2->so_rcv.sb_cc;
  945         }
  946         sb->st_dev = NODEV;
  947         if (unp->unp_ino == 0)
  948                 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
  949         sb->st_ino = unp->unp_ino;
  950         UNP_PCB_UNLOCK(unp);
  951         UNP_LINK_RUNLOCK();
  952         return (0);
  953 }
  954 
  955 static int
  956 uipc_shutdown(struct socket *so)
  957 {
  958         struct unpcb *unp;
  959 
  960         unp = sotounpcb(so);
  961         KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
  962 
  963         UNP_LINK_WLOCK();
  964         UNP_PCB_LOCK(unp);
  965         socantsendmore(so);
  966         unp_shutdown(unp);
  967         UNP_PCB_UNLOCK(unp);
  968         UNP_LINK_WUNLOCK();
  969         return (0);
  970 }
  971 
  972 static int
  973 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
  974 {
  975         struct unpcb *unp;
  976         const struct sockaddr *sa;
  977 
  978         unp = sotounpcb(so);
  979         KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
  980 
  981         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
  982         UNP_PCB_LOCK(unp);
  983         if (unp->unp_addr != NULL)
  984                 sa = (struct sockaddr *) unp->unp_addr;
  985         else
  986                 sa = &sun_noname;
  987         bcopy(sa, *nam, sa->sa_len);
  988         UNP_PCB_UNLOCK(unp);
  989         return (0);
  990 }
  991 
  992 static struct pr_usrreqs uipc_usrreqs_dgram = {
  993         .pru_abort =            uipc_abort,
  994         .pru_accept =           uipc_accept,
  995         .pru_attach =           uipc_attach,
  996         .pru_bind =             uipc_bind,
  997         .pru_connect =          uipc_connect,
  998         .pru_connect2 =         uipc_connect2,
  999         .pru_detach =           uipc_detach,
 1000         .pru_disconnect =       uipc_disconnect,
 1001         .pru_listen =           uipc_listen,
 1002         .pru_peeraddr =         uipc_peeraddr,
 1003         .pru_rcvd =             uipc_rcvd,
 1004         .pru_send =             uipc_send,
 1005         .pru_sense =            uipc_sense,
 1006         .pru_shutdown =         uipc_shutdown,
 1007         .pru_sockaddr =         uipc_sockaddr,
 1008         .pru_soreceive =        soreceive_dgram,
 1009         .pru_close =            uipc_close,
 1010 };
 1011 
 1012 static struct pr_usrreqs uipc_usrreqs_stream = {
 1013         .pru_abort =            uipc_abort,
 1014         .pru_accept =           uipc_accept,
 1015         .pru_attach =           uipc_attach,
 1016         .pru_bind =             uipc_bind,
 1017         .pru_connect =          uipc_connect,
 1018         .pru_connect2 =         uipc_connect2,
 1019         .pru_detach =           uipc_detach,
 1020         .pru_disconnect =       uipc_disconnect,
 1021         .pru_listen =           uipc_listen,
 1022         .pru_peeraddr =         uipc_peeraddr,
 1023         .pru_rcvd =             uipc_rcvd,
 1024         .pru_send =             uipc_send,
 1025         .pru_sense =            uipc_sense,
 1026         .pru_shutdown =         uipc_shutdown,
 1027         .pru_sockaddr =         uipc_sockaddr,
 1028         .pru_soreceive =        soreceive_generic,
 1029         .pru_close =            uipc_close,
 1030 };
 1031 
 1032 static int
 1033 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
 1034 {
 1035         struct unpcb *unp;
 1036         struct xucred xu;
 1037         int error, optval;
 1038 
 1039         if (sopt->sopt_level != 0)
 1040                 return (EINVAL);
 1041 
 1042         unp = sotounpcb(so);
 1043         KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
 1044         error = 0;
 1045         switch (sopt->sopt_dir) {
 1046         case SOPT_GET:
 1047                 switch (sopt->sopt_name) {
 1048                 case LOCAL_PEERCRED:
 1049                         UNP_PCB_LOCK(unp);
 1050                         if (unp->unp_flags & UNP_HAVEPC)
 1051                                 xu = unp->unp_peercred;
 1052                         else {
 1053                                 if (so->so_type == SOCK_STREAM)
 1054                                         error = ENOTCONN;
 1055                                 else
 1056                                         error = EINVAL;
 1057                         }
 1058                         UNP_PCB_UNLOCK(unp);
 1059                         if (error == 0)
 1060                                 error = sooptcopyout(sopt, &xu, sizeof(xu));
 1061                         break;
 1062 
 1063                 case LOCAL_CREDS:
 1064                         /* Unlocked read. */
 1065                         optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
 1066                         error = sooptcopyout(sopt, &optval, sizeof(optval));
 1067                         break;
 1068 
 1069                 case LOCAL_CONNWAIT:
 1070                         /* Unlocked read. */
 1071                         optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
 1072                         error = sooptcopyout(sopt, &optval, sizeof(optval));
 1073                         break;
 1074 
 1075                 default:
 1076                         error = EOPNOTSUPP;
 1077                         break;
 1078                 }
 1079                 break;
 1080 
 1081         case SOPT_SET:
 1082                 switch (sopt->sopt_name) {
 1083                 case LOCAL_CREDS:
 1084                 case LOCAL_CONNWAIT:
 1085                         error = sooptcopyin(sopt, &optval, sizeof(optval),
 1086                                             sizeof(optval));
 1087                         if (error)
 1088                                 break;
 1089 
 1090 #define OPTSET(bit) do {                                                \
 1091         UNP_PCB_LOCK(unp);                                              \
 1092         if (optval)                                                     \
 1093                 unp->unp_flags |= bit;                                  \
 1094         else                                                            \
 1095                 unp->unp_flags &= ~bit;                                 \
 1096         UNP_PCB_UNLOCK(unp);                                            \
 1097 } while (0)
 1098 
 1099                         switch (sopt->sopt_name) {
 1100                         case LOCAL_CREDS:
 1101                                 OPTSET(UNP_WANTCRED);
 1102                                 break;
 1103 
 1104                         case LOCAL_CONNWAIT:
 1105                                 OPTSET(UNP_CONNWAIT);
 1106                                 break;
 1107 
 1108                         default:
 1109                                 break;
 1110                         }
 1111                         break;
 1112 #undef  OPTSET
 1113                 default:
 1114                         error = ENOPROTOOPT;
 1115                         break;
 1116                 }
 1117                 break;
 1118 
 1119         default:
 1120                 error = EOPNOTSUPP;
 1121                 break;
 1122         }
 1123         return (error);
 1124 }
 1125 
 1126 static int
 1127 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 1128 {
 1129         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
 1130         struct vnode *vp;
 1131         struct socket *so2, *so3;
 1132         struct unpcb *unp, *unp2, *unp3;
 1133         int error, len, vfslocked;
 1134         struct nameidata nd;
 1135         char buf[SOCK_MAXADDRLEN];
 1136         struct sockaddr *sa;
 1137 
 1138         UNP_LINK_WLOCK_ASSERT();
 1139 
 1140         unp = sotounpcb(so);
 1141         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 1142 
 1143         len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
 1144         if (len <= 0)
 1145                 return (EINVAL);
 1146         bcopy(soun->sun_path, buf, len);
 1147         buf[len] = 0;
 1148 
 1149         UNP_PCB_LOCK(unp);
 1150         if (unp->unp_flags & UNP_CONNECTING) {
 1151                 UNP_PCB_UNLOCK(unp);
 1152                 return (EALREADY);
 1153         }
 1154         UNP_LINK_WUNLOCK();
 1155         unp->unp_flags |= UNP_CONNECTING;
 1156         UNP_PCB_UNLOCK(unp);
 1157 
 1158         sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 1159         NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf,
 1160             td);
 1161         error = namei(&nd);
 1162         if (error)
 1163                 vp = NULL;
 1164         else
 1165                 vp = nd.ni_vp;
 1166         ASSERT_VOP_LOCKED(vp, "unp_connect");
 1167         vfslocked = NDHASGIANT(&nd);
 1168         NDFREE(&nd, NDF_ONLY_PNBUF);
 1169         if (error)
 1170                 goto bad;
 1171 
 1172         if (vp->v_type != VSOCK) {
 1173                 error = ENOTSOCK;
 1174                 goto bad;
 1175         }
 1176 #ifdef MAC
 1177         error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
 1178         if (error)
 1179                 goto bad;
 1180 #endif
 1181         error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
 1182         if (error)
 1183                 goto bad;
 1184         VFS_UNLOCK_GIANT(vfslocked);
 1185 
 1186         unp = sotounpcb(so);
 1187         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 1188 
 1189         /*
 1190          * Lock linkage lock for two reasons: make sure v_socket is stable,
 1191          * and to protect simultaneous locking of multiple pcbs.
 1192          */
 1193         UNP_LINK_WLOCK();
 1194         so2 = vp->v_socket;
 1195         if (so2 == NULL) {
 1196                 error = ECONNREFUSED;
 1197                 goto bad2;
 1198         }
 1199         if (so->so_type != so2->so_type) {
 1200                 error = EPROTOTYPE;
 1201                 goto bad2;
 1202         }
 1203         if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
 1204                 if (so2->so_options & SO_ACCEPTCONN) {
 1205                         so3 = sonewconn(so2, 0);
 1206                 } else
 1207                         so3 = NULL;
 1208                 if (so3 == NULL) {
 1209                         error = ECONNREFUSED;
 1210                         goto bad2;
 1211                 }
 1212                 unp = sotounpcb(so);
 1213                 unp2 = sotounpcb(so2);
 1214                 unp3 = sotounpcb(so3);
 1215                 UNP_PCB_LOCK(unp);
 1216                 UNP_PCB_LOCK(unp2);
 1217                 UNP_PCB_LOCK(unp3);
 1218                 if (unp2->unp_addr != NULL) {
 1219                         bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
 1220                         unp3->unp_addr = (struct sockaddr_un *) sa;
 1221                         sa = NULL;
 1222                 }
 1223 
 1224                 /*
 1225                  * The connecter's (client's) credentials are copied from its
 1226                  * process structure at the time of connect() (which is now).
 1227                  */
 1228                 cru2x(td->td_ucred, &unp3->unp_peercred);
 1229                 unp3->unp_flags |= UNP_HAVEPC;
 1230 
 1231                 /*
 1232                  * The receiver's (server's) credentials are copied from the
 1233                  * unp_peercred member of socket on which the former called
 1234                  * listen(); uipc_listen() cached that process's credentials
 1235                  * at that time so we can use them now.
 1236                  */
 1237                 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
 1238                     ("unp_connect: listener without cached peercred"));
 1239                 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
 1240                     sizeof(unp->unp_peercred));
 1241                 unp->unp_flags |= UNP_HAVEPC;
 1242                 if (unp2->unp_flags & UNP_WANTCRED)
 1243                         unp3->unp_flags |= UNP_WANTCRED;
 1244                 UNP_PCB_UNLOCK(unp3);
 1245                 UNP_PCB_UNLOCK(unp2);
 1246                 UNP_PCB_UNLOCK(unp);
 1247 #ifdef MAC
 1248                 mac_socketpeer_set_from_socket(so, so3);
 1249                 mac_socketpeer_set_from_socket(so3, so);
 1250 #endif
 1251 
 1252                 so2 = so3;
 1253         }
 1254         unp = sotounpcb(so);
 1255         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 1256         unp2 = sotounpcb(so2);
 1257         KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
 1258         UNP_PCB_LOCK(unp);
 1259         UNP_PCB_LOCK(unp2);
 1260         error = unp_connect2(so, so2, PRU_CONNECT);
 1261         UNP_PCB_UNLOCK(unp2);
 1262         UNP_PCB_UNLOCK(unp);
 1263 bad2:
 1264         UNP_LINK_WUNLOCK();
 1265         if (vfslocked)
 1266                 /* 
 1267                  * Giant has been previously acquired. This means filesystem
 1268                  * isn't MPSAFE.  Do it once again.
 1269                  */
 1270                 mtx_lock(&Giant);
 1271 bad:
 1272         if (vp != NULL)
 1273                 vput(vp);
 1274         VFS_UNLOCK_GIANT(vfslocked);
 1275         free(sa, M_SONAME);
 1276         UNP_LINK_WLOCK();
 1277         UNP_PCB_LOCK(unp);
 1278         unp->unp_flags &= ~UNP_CONNECTING;
 1279         UNP_PCB_UNLOCK(unp);
 1280         return (error);
 1281 }
 1282 
 1283 static int
 1284 unp_connect2(struct socket *so, struct socket *so2, int req)
 1285 {
 1286         struct unpcb *unp;
 1287         struct unpcb *unp2;
 1288 
 1289         unp = sotounpcb(so);
 1290         KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
 1291         unp2 = sotounpcb(so2);
 1292         KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
 1293 
 1294         UNP_LINK_WLOCK_ASSERT();
 1295         UNP_PCB_LOCK_ASSERT(unp);
 1296         UNP_PCB_LOCK_ASSERT(unp2);
 1297 
 1298         if (so2->so_type != so->so_type)
 1299                 return (EPROTOTYPE);
 1300         unp->unp_conn = unp2;
 1301 
 1302         switch (so->so_type) {
 1303         case SOCK_DGRAM:
 1304                 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
 1305                 soisconnected(so);
 1306                 break;
 1307 
 1308         case SOCK_STREAM:
 1309                 unp2->unp_conn = unp;
 1310                 if (req == PRU_CONNECT &&
 1311                     ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
 1312                         soisconnecting(so);
 1313                 else
 1314                         soisconnected(so);
 1315                 soisconnected(so2);
 1316                 break;
 1317 
 1318         default:
 1319                 panic("unp_connect2");
 1320         }
 1321         return (0);
 1322 }
 1323 
 1324 static void
 1325 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
 1326 {
 1327         struct socket *so;
 1328 
 1329         KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
 1330 
 1331         UNP_LINK_WLOCK_ASSERT();
 1332         UNP_PCB_LOCK_ASSERT(unp);
 1333         UNP_PCB_LOCK_ASSERT(unp2);
 1334 
 1335         unp->unp_conn = NULL;
 1336         switch (unp->unp_socket->so_type) {
 1337         case SOCK_DGRAM:
 1338                 LIST_REMOVE(unp, unp_reflink);
 1339                 so = unp->unp_socket;
 1340                 SOCK_LOCK(so);
 1341                 so->so_state &= ~SS_ISCONNECTED;
 1342                 SOCK_UNLOCK(so);
 1343                 break;
 1344 
 1345         case SOCK_STREAM:
 1346                 soisdisconnected(unp->unp_socket);
 1347                 unp2->unp_conn = NULL;
 1348                 soisdisconnected(unp2->unp_socket);
 1349                 break;
 1350         }
 1351 }
 1352 
 1353 /*
 1354  * unp_pcblist() walks the global list of struct unpcb's to generate a
 1355  * pointer list, bumping the refcount on each unpcb.  It then copies them out
 1356  * sequentially, validating the generation number on each to see if it has
 1357  * been detached.  All of this is necessary because copyout() may sleep on
 1358  * disk I/O.
 1359  */
 1360 static int
 1361 unp_pcblist(SYSCTL_HANDLER_ARGS)
 1362 {
 1363         int error, i, n;
 1364         int freeunp;
 1365         struct unpcb *unp, **unp_list;
 1366         unp_gen_t gencnt;
 1367         struct xunpgen *xug;
 1368         struct unp_head *head;
 1369         struct xunpcb *xu;
 1370 
 1371         head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
 1372 
 1373         /*
 1374          * The process of preparing the PCB list is too time-consuming and
 1375          * resource-intensive to repeat twice on every request.
 1376          */
 1377         if (req->oldptr == NULL) {
 1378                 n = unp_count;
 1379                 req->oldidx = 2 * (sizeof *xug)
 1380                         + (n + n/8) * sizeof(struct xunpcb);
 1381                 return (0);
 1382         }
 1383 
 1384         if (req->newptr != NULL)
 1385                 return (EPERM);
 1386 
 1387         /*
 1388          * OK, now we're committed to doing something.
 1389          */
 1390         xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
 1391         UNP_LIST_LOCK();
 1392         gencnt = unp_gencnt;
 1393         n = unp_count;
 1394         UNP_LIST_UNLOCK();
 1395 
 1396         xug->xug_len = sizeof *xug;
 1397         xug->xug_count = n;
 1398         xug->xug_gen = gencnt;
 1399         xug->xug_sogen = so_gencnt;
 1400         error = SYSCTL_OUT(req, xug, sizeof *xug);
 1401         if (error) {
 1402                 free(xug, M_TEMP);
 1403                 return (error);
 1404         }
 1405 
 1406         unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
 1407 
 1408         UNP_LIST_LOCK();
 1409         for (unp = LIST_FIRST(head), i = 0; unp && i < n;
 1410              unp = LIST_NEXT(unp, unp_link)) {
 1411                 UNP_PCB_LOCK(unp);
 1412                 if (unp->unp_gencnt <= gencnt) {
 1413                         if (cr_cansee(req->td->td_ucred,
 1414                             unp->unp_socket->so_cred)) {
 1415                                 UNP_PCB_UNLOCK(unp);
 1416                                 continue;
 1417                         }
 1418                         unp_list[i++] = unp;
 1419                         unp->unp_refcount++;
 1420                 }
 1421                 UNP_PCB_UNLOCK(unp);
 1422         }
 1423         UNP_LIST_UNLOCK();
 1424         n = i;                  /* In case we lost some during malloc. */
 1425 
 1426         error = 0;
 1427         xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
 1428         for (i = 0; i < n; i++) {
 1429                 unp = unp_list[i];
 1430                 UNP_PCB_LOCK(unp);
 1431                 unp->unp_refcount--;
 1432                 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
 1433                         xu->xu_len = sizeof *xu;
 1434                         xu->xu_unpp = unp;
 1435                         /*
 1436                          * XXX - need more locking here to protect against
 1437                          * connect/disconnect races for SMP.
 1438                          */
 1439                         if (unp->unp_addr != NULL)
 1440                                 bcopy(unp->unp_addr, &xu->xu_addr,
 1441                                       unp->unp_addr->sun_len);
 1442                         if (unp->unp_conn != NULL &&
 1443                             unp->unp_conn->unp_addr != NULL)
 1444                                 bcopy(unp->unp_conn->unp_addr,
 1445                                       &xu->xu_caddr,
 1446                                       unp->unp_conn->unp_addr->sun_len);
 1447                         bcopy(unp, &xu->xu_unp, sizeof *unp);
 1448                         sotoxsocket(unp->unp_socket, &xu->xu_socket);
 1449                         UNP_PCB_UNLOCK(unp);
 1450                         error = SYSCTL_OUT(req, xu, sizeof *xu);
 1451                 } else {
 1452                         freeunp = (unp->unp_refcount == 0);
 1453                         UNP_PCB_UNLOCK(unp);
 1454                         if (freeunp) {
 1455                                 UNP_PCB_LOCK_DESTROY(unp);
 1456                                 uma_zfree(unp_zone, unp);
 1457                         }
 1458                 }
 1459         }
 1460         free(xu, M_TEMP);
 1461         if (!error) {
 1462                 /*
 1463                  * Give the user an updated idea of our state.  If the
 1464                  * generation differs from what we told her before, she knows
 1465                  * that something happened while we were processing this
 1466                  * request, and it might be necessary to retry.
 1467                  */
 1468                 xug->xug_gen = unp_gencnt;
 1469                 xug->xug_sogen = so_gencnt;
 1470                 xug->xug_count = unp_count;
 1471                 error = SYSCTL_OUT(req, xug, sizeof *xug);
 1472         }
 1473         free(unp_list, M_TEMP);
 1474         free(xug, M_TEMP);
 1475         return (error);
 1476 }
 1477 
 1478 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
 1479             (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
 1480             "List of active local datagram sockets");
 1481 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
 1482             (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
 1483             "List of active local stream sockets");
 1484 
 1485 static void
 1486 unp_shutdown(struct unpcb *unp)
 1487 {
 1488         struct unpcb *unp2;
 1489         struct socket *so;
 1490 
 1491         UNP_LINK_WLOCK_ASSERT();
 1492         UNP_PCB_LOCK_ASSERT(unp);
 1493 
 1494         unp2 = unp->unp_conn;
 1495         if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) {
 1496                 so = unp2->unp_socket;
 1497                 if (so != NULL)
 1498                         socantrcvmore(so);
 1499         }
 1500 }
 1501 
 1502 static void
 1503 unp_drop(struct unpcb *unp, int errno)
 1504 {
 1505         struct socket *so = unp->unp_socket;
 1506         struct unpcb *unp2;
 1507 
 1508         UNP_LINK_WLOCK_ASSERT();
 1509         UNP_PCB_LOCK_ASSERT(unp);
 1510 
 1511         so->so_error = errno;
 1512         unp2 = unp->unp_conn;
 1513         if (unp2 == NULL)
 1514                 return;
 1515         UNP_PCB_LOCK(unp2);
 1516         unp_disconnect(unp, unp2);
 1517         UNP_PCB_UNLOCK(unp2);
 1518 }
 1519 
 1520 static void
 1521 unp_freerights(struct file **rp, int fdcount)
 1522 {
 1523         int i;
 1524         struct file *fp;
 1525 
 1526         for (i = 0; i < fdcount; i++) {
 1527                 fp = *rp;
 1528                 *rp++ = NULL;
 1529                 unp_discard(fp);
 1530         }
 1531 }
 1532 
 1533 static int
 1534 unp_externalize(struct mbuf *control, struct mbuf **controlp)
 1535 {
 1536         struct thread *td = curthread;          /* XXX */
 1537         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
 1538         int i;
 1539         int *fdp;
 1540         struct file **rp;
 1541         struct file *fp;
 1542         void *data;
 1543         socklen_t clen = control->m_len, datalen;
 1544         int error, newfds;
 1545         int f;
 1546         u_int newlen;
 1547 
 1548         UNP_LINK_UNLOCK_ASSERT();
 1549 
 1550         error = 0;
 1551         if (controlp != NULL) /* controlp == NULL => free control messages */
 1552                 *controlp = NULL;
 1553         while (cm != NULL) {
 1554                 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
 1555                         error = EINVAL;
 1556                         break;
 1557                 }
 1558                 data = CMSG_DATA(cm);
 1559                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 1560                 if (cm->cmsg_level == SOL_SOCKET
 1561                     && cm->cmsg_type == SCM_RIGHTS) {
 1562                         newfds = datalen / sizeof(struct file *);
 1563                         rp = data;
 1564 
 1565                         /* If we're not outputting the descriptors free them. */
 1566                         if (error || controlp == NULL) {
 1567                                 unp_freerights(rp, newfds);
 1568                                 goto next;
 1569                         }
 1570                         FILEDESC_XLOCK(td->td_proc->p_fd);
 1571                         /* if the new FD's will not fit free them.  */
 1572                         if (!fdavail(td, newfds)) {
 1573                                 FILEDESC_XUNLOCK(td->td_proc->p_fd);
 1574                                 error = EMSGSIZE;
 1575                                 unp_freerights(rp, newfds);
 1576                                 goto next;
 1577                         }
 1578 
 1579                         /*
 1580                          * Now change each pointer to an fd in the global
 1581                          * table to an integer that is the index to the local
 1582                          * fd table entry that we set up to point to the
 1583                          * global one we are transferring.
 1584                          */
 1585                         newlen = newfds * sizeof(int);
 1586                         *controlp = sbcreatecontrol(NULL, newlen,
 1587                             SCM_RIGHTS, SOL_SOCKET);
 1588                         if (*controlp == NULL) {
 1589                                 FILEDESC_XUNLOCK(td->td_proc->p_fd);
 1590                                 error = E2BIG;
 1591                                 unp_freerights(rp, newfds);
 1592                                 goto next;
 1593                         }
 1594 
 1595                         fdp = (int *)
 1596                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1597                         for (i = 0; i < newfds; i++) {
 1598                                 if (fdalloc(td, 0, &f))
 1599                                         panic("unp_externalize fdalloc failed");
 1600                                 fp = *rp++;
 1601                                 td->td_proc->p_fd->fd_ofiles[f] = fp;
 1602                                 unp_externalize_fp(fp);
 1603                                 *fdp++ = f;
 1604                         }
 1605                         FILEDESC_XUNLOCK(td->td_proc->p_fd);
 1606                 } else {
 1607                         /* We can just copy anything else across. */
 1608                         if (error || controlp == NULL)
 1609                                 goto next;
 1610                         *controlp = sbcreatecontrol(NULL, datalen,
 1611                             cm->cmsg_type, cm->cmsg_level);
 1612                         if (*controlp == NULL) {
 1613                                 error = ENOBUFS;
 1614                                 goto next;
 1615                         }
 1616                         bcopy(data,
 1617                             CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
 1618                             datalen);
 1619                 }
 1620                 controlp = &(*controlp)->m_next;
 1621 
 1622 next:
 1623                 if (CMSG_SPACE(datalen) < clen) {
 1624                         clen -= CMSG_SPACE(datalen);
 1625                         cm = (struct cmsghdr *)
 1626                             ((caddr_t)cm + CMSG_SPACE(datalen));
 1627                 } else {
 1628                         clen = 0;
 1629                         cm = NULL;
 1630                 }
 1631         }
 1632 
 1633         m_freem(control);
 1634         return (error);
 1635 }
 1636 
 1637 static void
 1638 unp_zone_change(void *tag)
 1639 {
 1640 
 1641         uma_zone_set_max(unp_zone, maxsockets);
 1642 }
 1643 
 1644 static void
 1645 unp_init(void)
 1646 {
 1647 
 1648 #ifdef VIMAGE
 1649         if (!IS_DEFAULT_VNET(curvnet))
 1650                 return;
 1651 #endif
 1652         unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
 1653             NULL, NULL, UMA_ALIGN_PTR, 0);
 1654         if (unp_zone == NULL)
 1655                 panic("unp_init");
 1656         uma_zone_set_max(unp_zone, maxsockets);
 1657         EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
 1658             NULL, EVENTHANDLER_PRI_ANY);
 1659         LIST_INIT(&unp_dhead);
 1660         LIST_INIT(&unp_shead);
 1661         TASK_INIT(&unp_gc_task, 0, unp_gc, NULL);
 1662         UNP_LINK_LOCK_INIT();
 1663         UNP_LIST_LOCK_INIT();
 1664 }
 1665 
 1666 static int
 1667 unp_internalize(struct mbuf **controlp, struct thread *td)
 1668 {
 1669         struct mbuf *control = *controlp;
 1670         struct proc *p = td->td_proc;
 1671         struct filedesc *fdescp = p->p_fd;
 1672         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
 1673         struct cmsgcred *cmcred;
 1674         struct file **rp;
 1675         struct file *fp;
 1676         struct timeval *tv;
 1677         int i, fd, *fdp;
 1678         void *data;
 1679         socklen_t clen = control->m_len, datalen;
 1680         int error, oldfds;
 1681         u_int newlen;
 1682 
 1683         UNP_LINK_UNLOCK_ASSERT();
 1684 
 1685         error = 0;
 1686         *controlp = NULL;
 1687         while (cm != NULL) {
 1688                 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
 1689                     || cm->cmsg_len > clen) {
 1690                         error = EINVAL;
 1691                         goto out;
 1692                 }
 1693                 data = CMSG_DATA(cm);
 1694                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 1695 
 1696                 switch (cm->cmsg_type) {
 1697                 /*
 1698                  * Fill in credential information.
 1699                  */
 1700                 case SCM_CREDS:
 1701                         *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
 1702                             SCM_CREDS, SOL_SOCKET);
 1703                         if (*controlp == NULL) {
 1704                                 error = ENOBUFS;
 1705                                 goto out;
 1706                         }
 1707                         cmcred = (struct cmsgcred *)
 1708                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1709                         cmcred->cmcred_pid = p->p_pid;
 1710                         cmcred->cmcred_uid = td->td_ucred->cr_ruid;
 1711                         cmcred->cmcred_gid = td->td_ucred->cr_rgid;
 1712                         cmcred->cmcred_euid = td->td_ucred->cr_uid;
 1713                         cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
 1714                             CMGROUP_MAX);
 1715                         for (i = 0; i < cmcred->cmcred_ngroups; i++)
 1716                                 cmcred->cmcred_groups[i] =
 1717                                     td->td_ucred->cr_groups[i];
 1718                         break;
 1719 
 1720                 case SCM_RIGHTS:
 1721                         oldfds = datalen / sizeof (int);
 1722                         /*
 1723                          * Check that all the FDs passed in refer to legal
 1724                          * files.  If not, reject the entire operation.
 1725                          */
 1726                         fdp = data;
 1727                         FILEDESC_SLOCK(fdescp);
 1728                         for (i = 0; i < oldfds; i++) {
 1729                                 fd = *fdp++;
 1730                                 if ((unsigned)fd >= fdescp->fd_nfiles ||
 1731                                     fdescp->fd_ofiles[fd] == NULL) {
 1732                                         FILEDESC_SUNLOCK(fdescp);
 1733                                         error = EBADF;
 1734                                         goto out;
 1735                                 }
 1736                                 fp = fdescp->fd_ofiles[fd];
 1737                                 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
 1738                                         FILEDESC_SUNLOCK(fdescp);
 1739                                         error = EOPNOTSUPP;
 1740                                         goto out;
 1741                                 }
 1742 
 1743                         }
 1744 
 1745                         /*
 1746                          * Now replace the integer FDs with pointers to the
 1747                          * associated global file table entry..
 1748                          */
 1749                         newlen = oldfds * sizeof(struct file *);
 1750                         *controlp = sbcreatecontrol(NULL, newlen,
 1751                             SCM_RIGHTS, SOL_SOCKET);
 1752                         if (*controlp == NULL) {
 1753                                 FILEDESC_SUNLOCK(fdescp);
 1754                                 error = E2BIG;
 1755                                 goto out;
 1756                         }
 1757                         fdp = data;
 1758                         rp = (struct file **)
 1759                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1760                         for (i = 0; i < oldfds; i++) {
 1761                                 fp = fdescp->fd_ofiles[*fdp++];
 1762                                 *rp++ = fp;
 1763                                 unp_internalize_fp(fp);
 1764                         }
 1765                         FILEDESC_SUNLOCK(fdescp);
 1766                         break;
 1767 
 1768                 case SCM_TIMESTAMP:
 1769                         *controlp = sbcreatecontrol(NULL, sizeof(*tv),
 1770                             SCM_TIMESTAMP, SOL_SOCKET);
 1771                         if (*controlp == NULL) {
 1772                                 error = ENOBUFS;
 1773                                 goto out;
 1774                         }
 1775                         tv = (struct timeval *)
 1776                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1777                         microtime(tv);
 1778                         break;
 1779 
 1780                 default:
 1781                         error = EINVAL;
 1782                         goto out;
 1783                 }
 1784 
 1785                 controlp = &(*controlp)->m_next;
 1786                 if (CMSG_SPACE(datalen) < clen) {
 1787                         clen -= CMSG_SPACE(datalen);
 1788                         cm = (struct cmsghdr *)
 1789                             ((caddr_t)cm + CMSG_SPACE(datalen));
 1790                 } else {
 1791                         clen = 0;
 1792                         cm = NULL;
 1793                 }
 1794         }
 1795 
 1796 out:
 1797         m_freem(control);
 1798         return (error);
 1799 }
 1800 
 1801 static struct mbuf *
 1802 unp_addsockcred(struct thread *td, struct mbuf *control)
 1803 {
 1804         struct mbuf *m, *n, *n_prev;
 1805         struct sockcred *sc;
 1806         const struct cmsghdr *cm;
 1807         int ngroups;
 1808         int i;
 1809 
 1810         ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
 1811         m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
 1812         if (m == NULL)
 1813                 return (control);
 1814 
 1815         sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
 1816         sc->sc_uid = td->td_ucred->cr_ruid;
 1817         sc->sc_euid = td->td_ucred->cr_uid;
 1818         sc->sc_gid = td->td_ucred->cr_rgid;
 1819         sc->sc_egid = td->td_ucred->cr_gid;
 1820         sc->sc_ngroups = ngroups;
 1821         for (i = 0; i < sc->sc_ngroups; i++)
 1822                 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
 1823 
 1824         /*
 1825          * Unlink SCM_CREDS control messages (struct cmsgcred), since just
 1826          * created SCM_CREDS control message (struct sockcred) has another
 1827          * format.
 1828          */
 1829         if (control != NULL)
 1830                 for (n = control, n_prev = NULL; n != NULL;) {
 1831                         cm = mtod(n, struct cmsghdr *);
 1832                         if (cm->cmsg_level == SOL_SOCKET &&
 1833                             cm->cmsg_type == SCM_CREDS) {
 1834                                 if (n_prev == NULL)
 1835                                         control = n->m_next;
 1836                                 else
 1837                                         n_prev->m_next = n->m_next;
 1838                                 n = m_free(n);
 1839                         } else {
 1840                                 n_prev = n;
 1841                                 n = n->m_next;
 1842                         }
 1843                 }
 1844 
 1845         /* Prepend it to the head. */
 1846         m->m_next = control;
 1847         return (m);
 1848 }
 1849 
 1850 static struct unpcb *
 1851 fptounp(struct file *fp)
 1852 {
 1853         struct socket *so;
 1854 
 1855         if (fp->f_type != DTYPE_SOCKET)
 1856                 return (NULL);
 1857         if ((so = fp->f_data) == NULL)
 1858                 return (NULL);
 1859         if (so->so_proto->pr_domain != &localdomain)
 1860                 return (NULL);
 1861         return sotounpcb(so);
 1862 }
 1863 
 1864 static void
 1865 unp_discard(struct file *fp)
 1866 {
 1867 
 1868         unp_externalize_fp(fp);
 1869         (void) closef(fp, (struct thread *)NULL);
 1870 }
 1871 
 1872 static void
 1873 unp_internalize_fp(struct file *fp)
 1874 {
 1875         struct unpcb *unp;
 1876 
 1877         UNP_LINK_WLOCK();
 1878         if ((unp = fptounp(fp)) != NULL) {
 1879                 unp->unp_file = fp;
 1880                 unp->unp_msgcount++;
 1881         }
 1882         fhold(fp);
 1883         unp_rights++;
 1884         UNP_LINK_WUNLOCK();
 1885 }
 1886 
 1887 static void
 1888 unp_externalize_fp(struct file *fp)
 1889 {
 1890         struct unpcb *unp;
 1891 
 1892         UNP_LINK_WLOCK();
 1893         if ((unp = fptounp(fp)) != NULL)
 1894                 unp->unp_msgcount--;
 1895         unp_rights--;
 1896         UNP_LINK_WUNLOCK();
 1897 }
 1898 
 1899 /*
 1900  * unp_defer indicates whether additional work has been defered for a future
 1901  * pass through unp_gc().  It is thread local and does not require explicit
 1902  * synchronization.
 1903  */
 1904 static int      unp_marked;
 1905 static int      unp_unreachable;
 1906 
 1907 static void
 1908 unp_accessable(struct file *fp)
 1909 {
 1910         struct unpcb *unp;
 1911 
 1912         if ((unp = fptounp(fp)) == NULL)
 1913                 return;
 1914         if (unp->unp_gcflag & UNPGC_REF)
 1915                 return;
 1916         unp->unp_gcflag &= ~UNPGC_DEAD;
 1917         unp->unp_gcflag |= UNPGC_REF;
 1918         unp_marked++;
 1919 }
 1920 
 1921 static void
 1922 unp_gc_process(struct unpcb *unp)
 1923 {
 1924         struct socket *soa;
 1925         struct socket *so;
 1926         struct file *fp;
 1927 
 1928         /* Already processed. */
 1929         if (unp->unp_gcflag & UNPGC_SCANNED)
 1930                 return;
 1931         fp = unp->unp_file;
 1932 
 1933         /*
 1934          * Check for a socket potentially in a cycle.  It must be in a
 1935          * queue as indicated by msgcount, and this must equal the file
 1936          * reference count.  Note that when msgcount is 0 the file is NULL.
 1937          */
 1938         if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
 1939             unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
 1940                 unp->unp_gcflag |= UNPGC_DEAD;
 1941                 unp_unreachable++;
 1942                 return;
 1943         }
 1944 
 1945         /*
 1946          * Mark all sockets we reference with RIGHTS.
 1947          */
 1948         so = unp->unp_socket;
 1949         SOCKBUF_LOCK(&so->so_rcv);
 1950         unp_scan(so->so_rcv.sb_mb, unp_accessable);
 1951         SOCKBUF_UNLOCK(&so->so_rcv);
 1952 
 1953         /*
 1954          * Mark all sockets in our accept queue.
 1955          */
 1956         ACCEPT_LOCK();
 1957         TAILQ_FOREACH(soa, &so->so_comp, so_list) {
 1958                 SOCKBUF_LOCK(&soa->so_rcv);
 1959                 unp_scan(soa->so_rcv.sb_mb, unp_accessable);
 1960                 SOCKBUF_UNLOCK(&soa->so_rcv);
 1961         }
 1962         ACCEPT_UNLOCK();
 1963         unp->unp_gcflag |= UNPGC_SCANNED;
 1964 }
 1965 
 1966 static int unp_recycled;
 1967 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 
 1968     "Number of unreachable sockets claimed by the garbage collector.");
 1969 
 1970 static int unp_taskcount;
 1971 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 
 1972     "Number of times the garbage collector has run.");
 1973 
 1974 static void
 1975 unp_gc(__unused void *arg, int pending)
 1976 {
 1977         struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL };
 1978         struct unp_head **head;
 1979         struct file **unref;
 1980         struct unpcb *unp;
 1981         int i;
 1982 
 1983         unp_taskcount++;
 1984         UNP_LIST_LOCK();
 1985         /*
 1986          * First clear all gc flags from previous runs.
 1987          */
 1988         for (head = heads; *head != NULL; head++)
 1989                 LIST_FOREACH(unp, *head, unp_link)
 1990                         unp->unp_gcflag = 0;
 1991 
 1992         /*
 1993          * Scan marking all reachable sockets with UNPGC_REF.  Once a socket
 1994          * is reachable all of the sockets it references are reachable.
 1995          * Stop the scan once we do a complete loop without discovering
 1996          * a new reachable socket.
 1997          */
 1998         do {
 1999                 unp_unreachable = 0;
 2000                 unp_marked = 0;
 2001                 for (head = heads; *head != NULL; head++)
 2002                         LIST_FOREACH(unp, *head, unp_link)
 2003                                 unp_gc_process(unp);
 2004         } while (unp_marked);
 2005         UNP_LIST_UNLOCK();
 2006         if (unp_unreachable == 0)
 2007                 return;
 2008 
 2009         /*
 2010          * Allocate space for a local list of dead unpcbs.
 2011          */
 2012         unref = malloc(unp_unreachable * sizeof(struct file *),
 2013             M_TEMP, M_WAITOK);
 2014 
 2015         /*
 2016          * Iterate looking for sockets which have been specifically marked
 2017          * as as unreachable and store them locally.
 2018          */
 2019         UNP_LIST_LOCK();
 2020         for (i = 0, head = heads; *head != NULL; head++)
 2021                 LIST_FOREACH(unp, *head, unp_link)
 2022                         if (unp->unp_gcflag & UNPGC_DEAD) {
 2023                                 unref[i++] = unp->unp_file;
 2024                                 fhold(unp->unp_file);
 2025                                 KASSERT(unp->unp_file != NULL,
 2026                                     ("unp_gc: Invalid unpcb."));
 2027                                 KASSERT(i <= unp_unreachable,
 2028                                     ("unp_gc: incorrect unreachable count."));
 2029                         }
 2030         UNP_LIST_UNLOCK();
 2031 
 2032         /*
 2033          * Now flush all sockets, free'ing rights.  This will free the
 2034          * struct files associated with these sockets but leave each socket
 2035          * with one remaining ref.
 2036          */
 2037         for (i = 0; i < unp_unreachable; i++)
 2038                 sorflush(unref[i]->f_data);
 2039 
 2040         /*
 2041          * And finally release the sockets so they can be reclaimed.
 2042          */
 2043         for (i = 0; i < unp_unreachable; i++)
 2044                 fdrop(unref[i], NULL);
 2045         unp_recycled += unp_unreachable;
 2046         free(unref, M_TEMP);
 2047 }
 2048 
 2049 static void
 2050 unp_dispose(struct mbuf *m)
 2051 {
 2052 
 2053         if (m)
 2054                 unp_scan(m, unp_discard);
 2055 }
 2056 
 2057 static void
 2058 unp_scan(struct mbuf *m0, void (*op)(struct file *))
 2059 {
 2060         struct mbuf *m;
 2061         struct file **rp;
 2062         struct cmsghdr *cm;
 2063         void *data;
 2064         int i;
 2065         socklen_t clen, datalen;
 2066         int qfds;
 2067 
 2068         while (m0 != NULL) {
 2069                 for (m = m0; m; m = m->m_next) {
 2070                         if (m->m_type != MT_CONTROL)
 2071                                 continue;
 2072 
 2073                         cm = mtod(m, struct cmsghdr *);
 2074                         clen = m->m_len;
 2075 
 2076                         while (cm != NULL) {
 2077                                 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
 2078                                         break;
 2079 
 2080                                 data = CMSG_DATA(cm);
 2081                                 datalen = (caddr_t)cm + cm->cmsg_len
 2082                                     - (caddr_t)data;
 2083 
 2084                                 if (cm->cmsg_level == SOL_SOCKET &&
 2085                                     cm->cmsg_type == SCM_RIGHTS) {
 2086                                         qfds = datalen / sizeof (struct file *);
 2087                                         rp = data;
 2088                                         for (i = 0; i < qfds; i++)
 2089                                                 (*op)(*rp++);
 2090                                 }
 2091 
 2092                                 if (CMSG_SPACE(datalen) < clen) {
 2093                                         clen -= CMSG_SPACE(datalen);
 2094                                         cm = (struct cmsghdr *)
 2095                                             ((caddr_t)cm + CMSG_SPACE(datalen));
 2096                                 } else {
 2097                                         clen = 0;
 2098                                         cm = NULL;
 2099                                 }
 2100                         }
 2101                 }
 2102                 m0 = m0->m_act;
 2103         }
 2104 }
 2105 
 2106 #ifdef DDB
 2107 static void
 2108 db_print_indent(int indent)
 2109 {
 2110         int i;
 2111 
 2112         for (i = 0; i < indent; i++)
 2113                 db_printf(" ");
 2114 }
 2115 
 2116 static void
 2117 db_print_unpflags(int unp_flags)
 2118 {
 2119         int comma;
 2120 
 2121         comma = 0;
 2122         if (unp_flags & UNP_HAVEPC) {
 2123                 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
 2124                 comma = 1;
 2125         }
 2126         if (unp_flags & UNP_HAVEPCCACHED) {
 2127                 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
 2128                 comma = 1;
 2129         }
 2130         if (unp_flags & UNP_WANTCRED) {
 2131                 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
 2132                 comma = 1;
 2133         }
 2134         if (unp_flags & UNP_CONNWAIT) {
 2135                 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
 2136                 comma = 1;
 2137         }
 2138         if (unp_flags & UNP_CONNECTING) {
 2139                 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
 2140                 comma = 1;
 2141         }
 2142         if (unp_flags & UNP_BINDING) {
 2143                 db_printf("%sUNP_BINDING", comma ? ", " : "");
 2144                 comma = 1;
 2145         }
 2146 }
 2147 
 2148 static void
 2149 db_print_xucred(int indent, struct xucred *xu)
 2150 {
 2151         int comma, i;
 2152 
 2153         db_print_indent(indent);
 2154         db_printf("cr_version: %u   cr_uid: %u   cr_ngroups: %d\n",
 2155             xu->cr_version, xu->cr_uid, xu->cr_ngroups);
 2156         db_print_indent(indent);
 2157         db_printf("cr_groups: ");
 2158         comma = 0;
 2159         for (i = 0; i < xu->cr_ngroups; i++) {
 2160                 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
 2161                 comma = 1;
 2162         }
 2163         db_printf("\n");
 2164 }
 2165 
 2166 static void
 2167 db_print_unprefs(int indent, struct unp_head *uh)
 2168 {
 2169         struct unpcb *unp;
 2170         int counter;
 2171 
 2172         counter = 0;
 2173         LIST_FOREACH(unp, uh, unp_reflink) {
 2174                 if (counter % 4 == 0)
 2175                         db_print_indent(indent);
 2176                 db_printf("%p  ", unp);
 2177                 if (counter % 4 == 3)
 2178                         db_printf("\n");
 2179                 counter++;
 2180         }
 2181         if (counter != 0 && counter % 4 != 0)
 2182                 db_printf("\n");
 2183 }
 2184 
 2185 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
 2186 {
 2187         struct unpcb *unp;
 2188 
 2189         if (!have_addr) {
 2190                 db_printf("usage: show unpcb <addr>\n");
 2191                 return;
 2192         }
 2193         unp = (struct unpcb *)addr;
 2194 
 2195         db_printf("unp_socket: %p   unp_vnode: %p\n", unp->unp_socket,
 2196             unp->unp_vnode);
 2197 
 2198         db_printf("unp_ino: %d   unp_conn: %p\n", unp->unp_ino,
 2199             unp->unp_conn);
 2200 
 2201         db_printf("unp_refs:\n");
 2202         db_print_unprefs(2, &unp->unp_refs);
 2203 
 2204         /* XXXRW: Would be nice to print the full address, if any. */
 2205         db_printf("unp_addr: %p\n", unp->unp_addr);
 2206 
 2207         db_printf("unp_cc: %d   unp_mbcnt: %d   unp_gencnt: %llu\n",
 2208             unp->unp_cc, unp->unp_mbcnt,
 2209             (unsigned long long)unp->unp_gencnt);
 2210 
 2211         db_printf("unp_flags: %x (", unp->unp_flags);
 2212         db_print_unpflags(unp->unp_flags);
 2213         db_printf(")\n");
 2214 
 2215         db_printf("unp_peercred:\n");
 2216         db_print_xucred(2, &unp->unp_peercred);
 2217 
 2218         db_printf("unp_refcount: %u\n", unp->unp_refcount);
 2219 }
 2220 #endif

Cache object: 961cd4af13129b72b682559b70284f0d


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.