The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_mqueue.c

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    1 /*-
    2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  *
   26  */
   27 
   28 /*
   29  * POSIX message queue implementation.
   30  *
   31  * 1) A mqueue filesystem can be mounted, each message queue appears
   32  *    in mounted directory, user can change queue's permission and
   33  *    ownership, or remove a queue. Manually creating a file in the
   34  *    directory causes a message queue to be created in the kernel with
   35  *    default message queue attributes applied and same name used, this
   36  *    method is not advocated since mq_open syscall allows user to specify
   37  *    different attributes. Also the file system can be mounted multiple
   38  *    times at different mount points but shows same contents.
   39  *
   40  * 2) Standard POSIX message queue API. The syscalls do not use vfs layer,
   41  *    but directly operate on internal data structure, this allows user to
   42  *    use the IPC facility without having to mount mqueue file system.
   43  */
   44 
   45 #include <sys/cdefs.h>
   46 __FBSDID("$FreeBSD: releng/10.2/sys/kern/uipc_mqueue.c 280258 2015-03-19 13:37:36Z rwatson $");
   47 
   48 #include "opt_capsicum.h"
   49 #include "opt_compat.h"
   50 
   51 #include <sys/param.h>
   52 #include <sys/kernel.h>
   53 #include <sys/systm.h>
   54 #include <sys/limits.h>
   55 #include <sys/buf.h>
   56 #include <sys/capsicum.h>
   57 #include <sys/dirent.h>
   58 #include <sys/event.h>
   59 #include <sys/eventhandler.h>
   60 #include <sys/fcntl.h>
   61 #include <sys/file.h>
   62 #include <sys/filedesc.h>
   63 #include <sys/lock.h>
   64 #include <sys/malloc.h>
   65 #include <sys/module.h>
   66 #include <sys/mount.h>
   67 #include <sys/mqueue.h>
   68 #include <sys/mutex.h>
   69 #include <sys/namei.h>
   70 #include <sys/posix4.h>
   71 #include <sys/poll.h>
   72 #include <sys/priv.h>
   73 #include <sys/proc.h>
   74 #include <sys/queue.h>
   75 #include <sys/sysproto.h>
   76 #include <sys/stat.h>
   77 #include <sys/syscall.h>
   78 #include <sys/syscallsubr.h>
   79 #include <sys/sysent.h>
   80 #include <sys/sx.h>
   81 #include <sys/sysctl.h>
   82 #include <sys/taskqueue.h>
   83 #include <sys/unistd.h>
   84 #include <sys/vnode.h>
   85 #include <machine/atomic.h>
   86 
   87 FEATURE(p1003_1b_mqueue, "POSIX P1003.1B message queues support");
   88 
   89 /*
   90  * Limits and constants
   91  */
   92 #define MQFS_NAMELEN            NAME_MAX
   93 #define MQFS_DELEN              (8 + MQFS_NAMELEN)
   94 
   95 /* node types */
   96 typedef enum {
   97         mqfstype_none = 0,
   98         mqfstype_root,
   99         mqfstype_dir,
  100         mqfstype_this,
  101         mqfstype_parent,
  102         mqfstype_file,
  103         mqfstype_symlink,
  104 } mqfs_type_t;
  105 
  106 struct mqfs_node;
  107 
  108 /*
  109  * mqfs_info: describes a mqfs instance
  110  */
  111 struct mqfs_info {
  112         struct sx               mi_lock;
  113         struct mqfs_node        *mi_root;
  114         struct unrhdr           *mi_unrhdr;
  115 };
  116 
  117 struct mqfs_vdata {
  118         LIST_ENTRY(mqfs_vdata)  mv_link;
  119         struct mqfs_node        *mv_node;
  120         struct vnode            *mv_vnode;
  121         struct task             mv_task;
  122 };
  123 
  124 /*
  125  * mqfs_node: describes a node (file or directory) within a mqfs
  126  */
  127 struct mqfs_node {
  128         char                    mn_name[MQFS_NAMELEN+1];
  129         struct mqfs_info        *mn_info;
  130         struct mqfs_node        *mn_parent;
  131         LIST_HEAD(,mqfs_node)   mn_children;
  132         LIST_ENTRY(mqfs_node)   mn_sibling;
  133         LIST_HEAD(,mqfs_vdata)  mn_vnodes;
  134         int                     mn_refcount;
  135         mqfs_type_t             mn_type;
  136         int                     mn_deleted;
  137         uint32_t                mn_fileno;
  138         void                    *mn_data;
  139         struct timespec         mn_birth;
  140         struct timespec         mn_ctime;
  141         struct timespec         mn_atime;
  142         struct timespec         mn_mtime;
  143         uid_t                   mn_uid;
  144         gid_t                   mn_gid;
  145         int                     mn_mode;
  146 };
  147 
  148 #define VTON(vp)        (((struct mqfs_vdata *)((vp)->v_data))->mv_node)
  149 #define VTOMQ(vp)       ((struct mqueue *)(VTON(vp)->mn_data))
  150 #define VFSTOMQFS(m)    ((struct mqfs_info *)((m)->mnt_data))
  151 #define FPTOMQ(fp)      ((struct mqueue *)(((struct mqfs_node *) \
  152                                 (fp)->f_data)->mn_data))
  153 
  154 TAILQ_HEAD(msgq, mqueue_msg);
  155 
  156 struct mqueue;
  157 
  158 struct mqueue_notifier {
  159         LIST_ENTRY(mqueue_notifier)     nt_link;
  160         struct sigevent                 nt_sigev;
  161         ksiginfo_t                      nt_ksi;
  162         struct proc                     *nt_proc;
  163 };
  164 
  165 struct mqueue {
  166         struct mtx      mq_mutex;
  167         int             mq_flags;
  168         long            mq_maxmsg;
  169         long            mq_msgsize;
  170         long            mq_curmsgs;
  171         long            mq_totalbytes;
  172         struct msgq     mq_msgq;
  173         int             mq_receivers;
  174         int             mq_senders;
  175         struct selinfo  mq_rsel;
  176         struct selinfo  mq_wsel;
  177         struct mqueue_notifier  *mq_notifier;
  178 };
  179 
  180 #define MQ_RSEL         0x01
  181 #define MQ_WSEL         0x02
  182 
  183 struct mqueue_msg {
  184         TAILQ_ENTRY(mqueue_msg) msg_link;
  185         unsigned int    msg_prio;
  186         unsigned int    msg_size;
  187         /* following real data... */
  188 };
  189 
  190 static SYSCTL_NODE(_kern, OID_AUTO, mqueue, CTLFLAG_RW, 0,
  191         "POSIX real time message queue");
  192 
  193 static int      default_maxmsg  = 10;
  194 static int      default_msgsize = 1024;
  195 
  196 static int      maxmsg = 100;
  197 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsg, CTLFLAG_RW,
  198     &maxmsg, 0, "Default maximum messages in queue");
  199 static int      maxmsgsize = 16384;
  200 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmsgsize, CTLFLAG_RW,
  201     &maxmsgsize, 0, "Default maximum message size");
  202 static int      maxmq = 100;
  203 SYSCTL_INT(_kern_mqueue, OID_AUTO, maxmq, CTLFLAG_RW,
  204     &maxmq, 0, "maximum message queues");
  205 static int      curmq = 0;
  206 SYSCTL_INT(_kern_mqueue, OID_AUTO, curmq, CTLFLAG_RW,
  207     &curmq, 0, "current message queue number");
  208 static int      unloadable = 0;
  209 static MALLOC_DEFINE(M_MQUEUEDATA, "mqdata", "mqueue data");
  210 
  211 static eventhandler_tag exit_tag;
  212 
  213 /* Only one instance per-system */
  214 static struct mqfs_info         mqfs_data;
  215 static uma_zone_t               mqnode_zone;
  216 static uma_zone_t               mqueue_zone;
  217 static uma_zone_t               mvdata_zone;
  218 static uma_zone_t               mqnoti_zone;
  219 static struct vop_vector        mqfs_vnodeops;
  220 static struct fileops           mqueueops;
  221 
  222 /*
  223  * Directory structure construction and manipulation
  224  */
  225 #ifdef notyet
  226 static struct mqfs_node *mqfs_create_dir(struct mqfs_node *parent,
  227         const char *name, int namelen, struct ucred *cred, int mode);
  228 static struct mqfs_node *mqfs_create_link(struct mqfs_node *parent,
  229         const char *name, int namelen, struct ucred *cred, int mode);
  230 #endif
  231 
  232 static struct mqfs_node *mqfs_create_file(struct mqfs_node *parent,
  233         const char *name, int namelen, struct ucred *cred, int mode);
  234 static int      mqfs_destroy(struct mqfs_node *mn);
  235 static void     mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn);
  236 static void     mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn);
  237 static int      mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn);
  238 
  239 /*
  240  * Message queue construction and maniplation
  241  */
  242 static struct mqueue    *mqueue_alloc(const struct mq_attr *attr);
  243 static void     mqueue_free(struct mqueue *mq);
  244 static int      mqueue_send(struct mqueue *mq, const char *msg_ptr,
  245                         size_t msg_len, unsigned msg_prio, int waitok,
  246                         const struct timespec *abs_timeout);
  247 static int      mqueue_receive(struct mqueue *mq, char *msg_ptr,
  248                         size_t msg_len, unsigned *msg_prio, int waitok,
  249                         const struct timespec *abs_timeout);
  250 static int      _mqueue_send(struct mqueue *mq, struct mqueue_msg *msg,
  251                         int timo);
  252 static int      _mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg,
  253                         int timo);
  254 static void     mqueue_send_notification(struct mqueue *mq);
  255 static void     mqueue_fdclose(struct thread *td, int fd, struct file *fp);
  256 static void     mq_proc_exit(void *arg, struct proc *p);
  257 
  258 /*
  259  * kqueue filters
  260  */
  261 static void     filt_mqdetach(struct knote *kn);
  262 static int      filt_mqread(struct knote *kn, long hint);
  263 static int      filt_mqwrite(struct knote *kn, long hint);
  264 
  265 struct filterops mq_rfiltops = {
  266         .f_isfd = 1,
  267         .f_detach = filt_mqdetach,
  268         .f_event = filt_mqread,
  269 };
  270 struct filterops mq_wfiltops = {
  271         .f_isfd = 1,
  272         .f_detach = filt_mqdetach,
  273         .f_event = filt_mqwrite,
  274 };
  275 
  276 /*
  277  * Initialize fileno bitmap
  278  */
  279 static void
  280 mqfs_fileno_init(struct mqfs_info *mi)
  281 {
  282         struct unrhdr *up;
  283 
  284         up = new_unrhdr(1, INT_MAX, NULL);
  285         mi->mi_unrhdr = up;
  286 }
  287 
  288 /*
  289  * Tear down fileno bitmap
  290  */
  291 static void
  292 mqfs_fileno_uninit(struct mqfs_info *mi)
  293 {
  294         struct unrhdr *up;
  295 
  296         up = mi->mi_unrhdr;
  297         mi->mi_unrhdr = NULL;
  298         delete_unrhdr(up);
  299 }
  300 
  301 /*
  302  * Allocate a file number
  303  */
  304 static void
  305 mqfs_fileno_alloc(struct mqfs_info *mi, struct mqfs_node *mn)
  306 {
  307         /* make sure our parent has a file number */
  308         if (mn->mn_parent && !mn->mn_parent->mn_fileno)
  309                 mqfs_fileno_alloc(mi, mn->mn_parent);
  310 
  311         switch (mn->mn_type) {
  312         case mqfstype_root:
  313         case mqfstype_dir:
  314         case mqfstype_file:
  315         case mqfstype_symlink:
  316                 mn->mn_fileno = alloc_unr(mi->mi_unrhdr);
  317                 break;
  318         case mqfstype_this:
  319                 KASSERT(mn->mn_parent != NULL,
  320                     ("mqfstype_this node has no parent"));
  321                 mn->mn_fileno = mn->mn_parent->mn_fileno;
  322                 break;
  323         case mqfstype_parent:
  324                 KASSERT(mn->mn_parent != NULL,
  325                     ("mqfstype_parent node has no parent"));
  326                 if (mn->mn_parent == mi->mi_root) {
  327                         mn->mn_fileno = mn->mn_parent->mn_fileno;
  328                         break;
  329                 }
  330                 KASSERT(mn->mn_parent->mn_parent != NULL,
  331                     ("mqfstype_parent node has no grandparent"));
  332                 mn->mn_fileno = mn->mn_parent->mn_parent->mn_fileno;
  333                 break;
  334         default:
  335                 KASSERT(0,
  336                     ("mqfs_fileno_alloc() called for unknown type node: %d",
  337                         mn->mn_type));
  338                 break;
  339         }
  340 }
  341 
  342 /*
  343  * Release a file number
  344  */
  345 static void
  346 mqfs_fileno_free(struct mqfs_info *mi, struct mqfs_node *mn)
  347 {
  348         switch (mn->mn_type) {
  349         case mqfstype_root:
  350         case mqfstype_dir:
  351         case mqfstype_file:
  352         case mqfstype_symlink:
  353                 free_unr(mi->mi_unrhdr, mn->mn_fileno);
  354                 break;
  355         case mqfstype_this:
  356         case mqfstype_parent:
  357                 /* ignore these, as they don't "own" their file number */
  358                 break;
  359         default:
  360                 KASSERT(0,
  361                     ("mqfs_fileno_free() called for unknown type node: %d", 
  362                         mn->mn_type));
  363                 break;
  364         }
  365 }
  366 
  367 static __inline struct mqfs_node *
  368 mqnode_alloc(void)
  369 {
  370         return uma_zalloc(mqnode_zone, M_WAITOK | M_ZERO);
  371 }
  372 
  373 static __inline void
  374 mqnode_free(struct mqfs_node *node)
  375 {
  376         uma_zfree(mqnode_zone, node);
  377 }
  378 
  379 static __inline void
  380 mqnode_addref(struct mqfs_node *node)
  381 {
  382         atomic_fetchadd_int(&node->mn_refcount, 1);
  383 }
  384 
  385 static __inline void
  386 mqnode_release(struct mqfs_node *node)
  387 {
  388         struct mqfs_info *mqfs;
  389         int old, exp;
  390 
  391         mqfs = node->mn_info;
  392         old = atomic_fetchadd_int(&node->mn_refcount, -1);
  393         if (node->mn_type == mqfstype_dir ||
  394             node->mn_type == mqfstype_root)
  395                 exp = 3; /* include . and .. */
  396         else
  397                 exp = 1;
  398         if (old == exp) {
  399                 int locked = sx_xlocked(&mqfs->mi_lock);
  400                 if (!locked)
  401                         sx_xlock(&mqfs->mi_lock);
  402                 mqfs_destroy(node);
  403                 if (!locked)
  404                         sx_xunlock(&mqfs->mi_lock);
  405         }
  406 }
  407 
  408 /*
  409  * Add a node to a directory
  410  */
  411 static int
  412 mqfs_add_node(struct mqfs_node *parent, struct mqfs_node *node)
  413 {
  414         KASSERT(parent != NULL, ("%s(): parent is NULL", __func__));
  415         KASSERT(parent->mn_info != NULL,
  416             ("%s(): parent has no mn_info", __func__));
  417         KASSERT(parent->mn_type == mqfstype_dir ||
  418             parent->mn_type == mqfstype_root,
  419             ("%s(): parent is not a directory", __func__));
  420 
  421         node->mn_info = parent->mn_info;
  422         node->mn_parent = parent;
  423         LIST_INIT(&node->mn_children);
  424         LIST_INIT(&node->mn_vnodes);
  425         LIST_INSERT_HEAD(&parent->mn_children, node, mn_sibling);
  426         mqnode_addref(parent);
  427         return (0);
  428 }
  429 
  430 static struct mqfs_node *
  431 mqfs_create_node(const char *name, int namelen, struct ucred *cred, int mode,
  432         int nodetype)
  433 {
  434         struct mqfs_node *node;
  435 
  436         node = mqnode_alloc();
  437         strncpy(node->mn_name, name, namelen);
  438         node->mn_type = nodetype;
  439         node->mn_refcount = 1;
  440         vfs_timestamp(&node->mn_birth);
  441         node->mn_ctime = node->mn_atime = node->mn_mtime
  442                 = node->mn_birth;
  443         node->mn_uid = cred->cr_uid;
  444         node->mn_gid = cred->cr_gid;
  445         node->mn_mode = mode;
  446         return (node);
  447 }
  448 
  449 /*
  450  * Create a file
  451  */
  452 static struct mqfs_node *
  453 mqfs_create_file(struct mqfs_node *parent, const char *name, int namelen,
  454         struct ucred *cred, int mode)
  455 {
  456         struct mqfs_node *node;
  457 
  458         node = mqfs_create_node(name, namelen, cred, mode, mqfstype_file);
  459         if (mqfs_add_node(parent, node) != 0) {
  460                 mqnode_free(node);
  461                 return (NULL);
  462         }
  463         return (node);
  464 }
  465 
  466 /*
  467  * Add . and .. to a directory
  468  */
  469 static int
  470 mqfs_fixup_dir(struct mqfs_node *parent)
  471 {
  472         struct mqfs_node *dir;
  473 
  474         dir = mqnode_alloc();
  475         dir->mn_name[0] = '.';
  476         dir->mn_type = mqfstype_this;
  477         dir->mn_refcount = 1;
  478         if (mqfs_add_node(parent, dir) != 0) {
  479                 mqnode_free(dir);
  480                 return (-1);
  481         }
  482 
  483         dir = mqnode_alloc();
  484         dir->mn_name[0] = dir->mn_name[1] = '.';
  485         dir->mn_type = mqfstype_parent;
  486         dir->mn_refcount = 1;
  487 
  488         if (mqfs_add_node(parent, dir) != 0) {
  489                 mqnode_free(dir);
  490                 return (-1);
  491         }
  492 
  493         return (0);
  494 }
  495 
  496 #ifdef notyet
  497 
  498 /*
  499  * Create a directory
  500  */
  501 static struct mqfs_node *
  502 mqfs_create_dir(struct mqfs_node *parent, const char *name, int namelen,
  503         struct ucred *cred, int mode)
  504 {
  505         struct mqfs_node *node;
  506 
  507         node = mqfs_create_node(name, namelen, cred, mode, mqfstype_dir);
  508         if (mqfs_add_node(parent, node) != 0) {
  509                 mqnode_free(node);
  510                 return (NULL);
  511         }
  512 
  513         if (mqfs_fixup_dir(node) != 0) {
  514                 mqfs_destroy(node);
  515                 return (NULL);
  516         }
  517         return (node);
  518 }
  519 
  520 /*
  521  * Create a symlink
  522  */
  523 static struct mqfs_node *
  524 mqfs_create_link(struct mqfs_node *parent, const char *name, int namelen,
  525         struct ucred *cred, int mode)
  526 {
  527         struct mqfs_node *node;
  528 
  529         node = mqfs_create_node(name, namelen, cred, mode, mqfstype_symlink);
  530         if (mqfs_add_node(parent, node) != 0) {
  531                 mqnode_free(node);
  532                 return (NULL);
  533         }
  534         return (node);
  535 }
  536 
  537 #endif
  538 
  539 /*
  540  * Destroy a node or a tree of nodes
  541  */
  542 static int
  543 mqfs_destroy(struct mqfs_node *node)
  544 {
  545         struct mqfs_node *parent;
  546 
  547         KASSERT(node != NULL,
  548             ("%s(): node is NULL", __func__));
  549         KASSERT(node->mn_info != NULL,
  550             ("%s(): node has no mn_info", __func__));
  551 
  552         /* destroy children */
  553         if (node->mn_type == mqfstype_dir || node->mn_type == mqfstype_root)
  554                 while (! LIST_EMPTY(&node->mn_children))
  555                         mqfs_destroy(LIST_FIRST(&node->mn_children));
  556 
  557         /* unlink from parent */
  558         if ((parent = node->mn_parent) != NULL) {
  559                 KASSERT(parent->mn_info == node->mn_info,
  560                     ("%s(): parent has different mn_info", __func__));
  561                 LIST_REMOVE(node, mn_sibling);
  562         }
  563 
  564         if (node->mn_fileno != 0)
  565                 mqfs_fileno_free(node->mn_info, node);
  566         if (node->mn_data != NULL)
  567                 mqueue_free(node->mn_data);
  568         mqnode_free(node);
  569         return (0);
  570 }
  571 
  572 /*
  573  * Mount a mqfs instance
  574  */
  575 static int
  576 mqfs_mount(struct mount *mp)
  577 {
  578         struct statfs *sbp;
  579 
  580         if (mp->mnt_flag & MNT_UPDATE)
  581                 return (EOPNOTSUPP);
  582 
  583         mp->mnt_data = &mqfs_data;
  584         MNT_ILOCK(mp);
  585         mp->mnt_flag |= MNT_LOCAL;
  586         MNT_IUNLOCK(mp);
  587         vfs_getnewfsid(mp);
  588 
  589         sbp = &mp->mnt_stat;
  590         vfs_mountedfrom(mp, "mqueue");
  591         sbp->f_bsize = PAGE_SIZE;
  592         sbp->f_iosize = PAGE_SIZE;
  593         sbp->f_blocks = 1;
  594         sbp->f_bfree = 0;
  595         sbp->f_bavail = 0;
  596         sbp->f_files = 1;
  597         sbp->f_ffree = 0;
  598         return (0);
  599 }
  600 
  601 /*
  602  * Unmount a mqfs instance
  603  */
  604 static int
  605 mqfs_unmount(struct mount *mp, int mntflags)
  606 {
  607         int error;
  608 
  609         error = vflush(mp, 0, (mntflags & MNT_FORCE) ?  FORCECLOSE : 0,
  610             curthread);
  611         return (error);
  612 }
  613 
  614 /*
  615  * Return a root vnode
  616  */
  617 static int
  618 mqfs_root(struct mount *mp, int flags, struct vnode **vpp)
  619 {
  620         struct mqfs_info *mqfs;
  621         int ret;
  622 
  623         mqfs = VFSTOMQFS(mp);
  624         ret = mqfs_allocv(mp, vpp, mqfs->mi_root);
  625         return (ret);
  626 }
  627 
  628 /*
  629  * Return filesystem stats
  630  */
  631 static int
  632 mqfs_statfs(struct mount *mp, struct statfs *sbp)
  633 {
  634         /* XXX update statistics */
  635         return (0);
  636 }
  637 
  638 /*
  639  * Initialize a mqfs instance
  640  */
  641 static int
  642 mqfs_init(struct vfsconf *vfc)
  643 {
  644         struct mqfs_node *root;
  645         struct mqfs_info *mi;
  646 
  647         mqnode_zone = uma_zcreate("mqnode", sizeof(struct mqfs_node),
  648                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  649         mqueue_zone = uma_zcreate("mqueue", sizeof(struct mqueue),
  650                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  651         mvdata_zone = uma_zcreate("mvdata",
  652                 sizeof(struct mqfs_vdata), NULL, NULL, NULL,
  653                 NULL, UMA_ALIGN_PTR, 0);
  654         mqnoti_zone = uma_zcreate("mqnotifier", sizeof(struct mqueue_notifier),
  655                 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
  656         mi = &mqfs_data;
  657         sx_init(&mi->mi_lock, "mqfs lock");
  658         /* set up the root diretory */
  659         root = mqfs_create_node("/", 1, curthread->td_ucred, 01777,
  660                 mqfstype_root);
  661         root->mn_info = mi;
  662         LIST_INIT(&root->mn_children);
  663         LIST_INIT(&root->mn_vnodes);
  664         mi->mi_root = root;
  665         mqfs_fileno_init(mi);
  666         mqfs_fileno_alloc(mi, root);
  667         mqfs_fixup_dir(root);
  668         exit_tag = EVENTHANDLER_REGISTER(process_exit, mq_proc_exit, NULL,
  669             EVENTHANDLER_PRI_ANY);
  670         mq_fdclose = mqueue_fdclose;
  671         p31b_setcfg(CTL_P1003_1B_MESSAGE_PASSING, _POSIX_MESSAGE_PASSING);
  672         return (0);
  673 }
  674 
  675 /*
  676  * Destroy a mqfs instance
  677  */
  678 static int
  679 mqfs_uninit(struct vfsconf *vfc)
  680 {
  681         struct mqfs_info *mi;
  682 
  683         if (!unloadable)
  684                 return (EOPNOTSUPP);
  685         EVENTHANDLER_DEREGISTER(process_exit, exit_tag);
  686         mi = &mqfs_data;
  687         mqfs_destroy(mi->mi_root);
  688         mi->mi_root = NULL;
  689         mqfs_fileno_uninit(mi);
  690         sx_destroy(&mi->mi_lock);
  691         uma_zdestroy(mqnode_zone);
  692         uma_zdestroy(mqueue_zone);
  693         uma_zdestroy(mvdata_zone);
  694         uma_zdestroy(mqnoti_zone);
  695         return (0);
  696 }
  697 
  698 /*
  699  * task routine
  700  */
  701 static void
  702 do_recycle(void *context, int pending __unused)
  703 {
  704         struct vnode *vp = (struct vnode *)context;
  705 
  706         vrecycle(vp);
  707         vdrop(vp);
  708 }
  709 
  710 /*
  711  * Allocate a vnode
  712  */
  713 static int
  714 mqfs_allocv(struct mount *mp, struct vnode **vpp, struct mqfs_node *pn)
  715 {
  716         struct mqfs_vdata *vd;
  717         struct mqfs_info  *mqfs;
  718         struct vnode *newvpp;
  719         int error;
  720 
  721         mqfs = pn->mn_info;
  722         *vpp = NULL;
  723         sx_xlock(&mqfs->mi_lock);
  724         LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
  725                 if (vd->mv_vnode->v_mount == mp) {
  726                         vhold(vd->mv_vnode);
  727                         break;
  728                 }
  729         }
  730 
  731         if (vd != NULL) {
  732 found:
  733                 *vpp = vd->mv_vnode;
  734                 sx_xunlock(&mqfs->mi_lock);
  735                 error = vget(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
  736                 vdrop(*vpp);
  737                 return (error);
  738         }
  739         sx_xunlock(&mqfs->mi_lock);
  740 
  741         error = getnewvnode("mqueue", mp, &mqfs_vnodeops, &newvpp);
  742         if (error)
  743                 return (error);
  744         vn_lock(newvpp, LK_EXCLUSIVE | LK_RETRY);
  745         error = insmntque(newvpp, mp);
  746         if (error != 0)
  747                 return (error);
  748 
  749         sx_xlock(&mqfs->mi_lock);
  750         /*
  751          * Check if it has already been allocated
  752          * while we were blocked.
  753          */
  754         LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
  755                 if (vd->mv_vnode->v_mount == mp) {
  756                         vhold(vd->mv_vnode);
  757                         sx_xunlock(&mqfs->mi_lock);
  758 
  759                         vgone(newvpp);
  760                         vput(newvpp);
  761                         goto found;
  762                 }
  763         }
  764 
  765         *vpp = newvpp;
  766 
  767         vd = uma_zalloc(mvdata_zone, M_WAITOK);
  768         (*vpp)->v_data = vd;
  769         vd->mv_vnode = *vpp;
  770         vd->mv_node = pn;
  771         TASK_INIT(&vd->mv_task, 0, do_recycle, *vpp);
  772         LIST_INSERT_HEAD(&pn->mn_vnodes, vd, mv_link);
  773         mqnode_addref(pn);
  774         switch (pn->mn_type) {
  775         case mqfstype_root:
  776                 (*vpp)->v_vflag = VV_ROOT;
  777                 /* fall through */
  778         case mqfstype_dir:
  779         case mqfstype_this:
  780         case mqfstype_parent:
  781                 (*vpp)->v_type = VDIR;
  782                 break;
  783         case mqfstype_file:
  784                 (*vpp)->v_type = VREG;
  785                 break;
  786         case mqfstype_symlink:
  787                 (*vpp)->v_type = VLNK;
  788                 break;
  789         case mqfstype_none:
  790                 KASSERT(0, ("mqfs_allocf called for null node\n"));
  791         default:
  792                 panic("%s has unexpected type: %d", pn->mn_name, pn->mn_type);
  793         }
  794         sx_xunlock(&mqfs->mi_lock);
  795         return (0);
  796 }
  797 
  798 /* 
  799  * Search a directory entry
  800  */
  801 static struct mqfs_node *
  802 mqfs_search(struct mqfs_node *pd, const char *name, int len)
  803 {
  804         struct mqfs_node *pn;
  805 
  806         sx_assert(&pd->mn_info->mi_lock, SX_LOCKED);
  807         LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
  808                 if (strncmp(pn->mn_name, name, len) == 0 &&
  809                     pn->mn_name[len] == '\0')
  810                         return (pn);
  811         }
  812         return (NULL);
  813 }
  814 
  815 /*
  816  * Look up a file or directory.
  817  */
  818 static int
  819 mqfs_lookupx(struct vop_cachedlookup_args *ap)
  820 {
  821         struct componentname *cnp;
  822         struct vnode *dvp, **vpp;
  823         struct mqfs_node *pd;
  824         struct mqfs_node *pn;
  825         struct mqfs_info *mqfs;
  826         int nameiop, flags, error, namelen;
  827         char *pname;
  828         struct thread *td;
  829 
  830         cnp = ap->a_cnp;
  831         vpp = ap->a_vpp;
  832         dvp = ap->a_dvp;
  833         pname = cnp->cn_nameptr;
  834         namelen = cnp->cn_namelen;
  835         td = cnp->cn_thread;
  836         flags = cnp->cn_flags;
  837         nameiop = cnp->cn_nameiop;
  838         pd = VTON(dvp);
  839         pn = NULL;
  840         mqfs = pd->mn_info;
  841         *vpp = NULLVP;
  842 
  843         if (dvp->v_type != VDIR)
  844                 return (ENOTDIR);
  845 
  846         error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
  847         if (error)
  848                 return (error);
  849 
  850         /* shortcut: check if the name is too long */
  851         if (cnp->cn_namelen >= MQFS_NAMELEN)
  852                 return (ENOENT);
  853 
  854         /* self */
  855         if (namelen == 1 && pname[0] == '.') {
  856                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  857                         return (EINVAL);
  858                 pn = pd;
  859                 *vpp = dvp;
  860                 VREF(dvp);
  861                 return (0);
  862         }
  863 
  864         /* parent */
  865         if (cnp->cn_flags & ISDOTDOT) {
  866                 if (dvp->v_vflag & VV_ROOT)
  867                         return (EIO);
  868                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  869                         return (EINVAL);
  870                 VOP_UNLOCK(dvp, 0);
  871                 KASSERT(pd->mn_parent, ("non-root directory has no parent"));
  872                 pn = pd->mn_parent;
  873                 error = mqfs_allocv(dvp->v_mount, vpp, pn);
  874                 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
  875                 return (error);
  876         }
  877 
  878         /* named node */
  879         sx_xlock(&mqfs->mi_lock);
  880         pn = mqfs_search(pd, pname, namelen);
  881         if (pn != NULL)
  882                 mqnode_addref(pn);
  883         sx_xunlock(&mqfs->mi_lock);
  884         
  885         /* found */
  886         if (pn != NULL) {
  887                 /* DELETE */
  888                 if (nameiop == DELETE && (flags & ISLASTCN)) {
  889                         error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  890                         if (error) {
  891                                 mqnode_release(pn);
  892                                 return (error);
  893                         }
  894                         if (*vpp == dvp) {
  895                                 VREF(dvp);
  896                                 *vpp = dvp;
  897                                 mqnode_release(pn);
  898                                 return (0);
  899                         }
  900                 }
  901 
  902                 /* allocate vnode */
  903                 error = mqfs_allocv(dvp->v_mount, vpp, pn);
  904                 mqnode_release(pn);
  905                 if (error == 0 && cnp->cn_flags & MAKEENTRY)
  906                         cache_enter(dvp, *vpp, cnp);
  907                 return (error);
  908         }
  909         
  910         /* not found */
  911 
  912         /* will create a new entry in the directory ? */
  913         if ((nameiop == CREATE || nameiop == RENAME) && (flags & LOCKPARENT)
  914             && (flags & ISLASTCN)) {
  915                 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  916                 if (error)
  917                         return (error);
  918                 cnp->cn_flags |= SAVENAME;
  919                 return (EJUSTRETURN);
  920         }
  921         return (ENOENT);
  922 }
  923 
  924 #if 0
  925 struct vop_lookup_args {
  926         struct vop_generic_args a_gen;
  927         struct vnode *a_dvp;
  928         struct vnode **a_vpp;
  929         struct componentname *a_cnp;
  930 };
  931 #endif
  932 
  933 /*
  934  * vnode lookup operation
  935  */
  936 static int
  937 mqfs_lookup(struct vop_cachedlookup_args *ap)
  938 {
  939         int rc;
  940 
  941         rc = mqfs_lookupx(ap);
  942         return (rc);
  943 }
  944 
  945 #if 0
  946 struct vop_create_args {
  947         struct vnode *a_dvp;
  948         struct vnode **a_vpp;
  949         struct componentname *a_cnp;
  950         struct vattr *a_vap;
  951 };
  952 #endif
  953 
  954 /*
  955  * vnode creation operation
  956  */
  957 static int
  958 mqfs_create(struct vop_create_args *ap)
  959 {
  960         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
  961         struct componentname *cnp = ap->a_cnp;
  962         struct mqfs_node *pd;
  963         struct mqfs_node *pn;
  964         struct mqueue *mq;
  965         int error;
  966 
  967         pd = VTON(ap->a_dvp);
  968         if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
  969                 return (ENOTDIR);
  970         mq = mqueue_alloc(NULL);
  971         if (mq == NULL)
  972                 return (EAGAIN);
  973         sx_xlock(&mqfs->mi_lock);
  974         if ((cnp->cn_flags & HASBUF) == 0)
  975                 panic("%s: no name", __func__);
  976         pn = mqfs_create_file(pd, cnp->cn_nameptr, cnp->cn_namelen,
  977                 cnp->cn_cred, ap->a_vap->va_mode);
  978         if (pn == NULL) {
  979                 sx_xunlock(&mqfs->mi_lock);
  980                 error = ENOSPC;
  981         } else {
  982                 mqnode_addref(pn);
  983                 sx_xunlock(&mqfs->mi_lock);
  984                 error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
  985                 mqnode_release(pn);
  986                 if (error)
  987                         mqfs_destroy(pn);
  988                 else
  989                         pn->mn_data = mq;
  990         }
  991         if (error)
  992                 mqueue_free(mq);
  993         return (error);
  994 }
  995 
  996 /*
  997  * Remove an entry
  998  */
  999 static
 1000 int do_unlink(struct mqfs_node *pn, struct ucred *ucred)
 1001 {
 1002         struct mqfs_node *parent;
 1003         struct mqfs_vdata *vd;
 1004         int error = 0;
 1005 
 1006         sx_assert(&pn->mn_info->mi_lock, SX_LOCKED);
 1007 
 1008         if (ucred->cr_uid != pn->mn_uid &&
 1009             (error = priv_check_cred(ucred, PRIV_MQ_ADMIN, 0)) != 0)
 1010                 error = EACCES;
 1011         else if (!pn->mn_deleted) {
 1012                 parent = pn->mn_parent;
 1013                 pn->mn_parent = NULL;
 1014                 pn->mn_deleted = 1;
 1015                 LIST_REMOVE(pn, mn_sibling);
 1016                 LIST_FOREACH(vd, &pn->mn_vnodes, mv_link) {
 1017                         cache_purge(vd->mv_vnode);
 1018                         vhold(vd->mv_vnode);
 1019                         taskqueue_enqueue(taskqueue_thread, &vd->mv_task);
 1020                 }
 1021                 mqnode_release(pn);
 1022                 mqnode_release(parent);
 1023         } else
 1024                 error = ENOENT;
 1025         return (error);
 1026 }
 1027 
 1028 #if 0
 1029 struct vop_remove_args {
 1030         struct vnode *a_dvp;
 1031         struct vnode *a_vp;
 1032         struct componentname *a_cnp;
 1033 };
 1034 #endif
 1035 
 1036 /*
 1037  * vnode removal operation
 1038  */
 1039 static int
 1040 mqfs_remove(struct vop_remove_args *ap)
 1041 {
 1042         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
 1043         struct mqfs_node *pn;
 1044         int error;
 1045 
 1046         if (ap->a_vp->v_type == VDIR)
 1047                 return (EPERM);
 1048         pn = VTON(ap->a_vp);
 1049         sx_xlock(&mqfs->mi_lock);
 1050         error = do_unlink(pn, ap->a_cnp->cn_cred);
 1051         sx_xunlock(&mqfs->mi_lock);
 1052         return (error);
 1053 }
 1054 
 1055 #if 0
 1056 struct vop_inactive_args {
 1057         struct vnode *a_vp;
 1058         struct thread *a_td;
 1059 };
 1060 #endif
 1061 
 1062 static int
 1063 mqfs_inactive(struct vop_inactive_args *ap)
 1064 {
 1065         struct mqfs_node *pn = VTON(ap->a_vp);
 1066 
 1067         if (pn->mn_deleted)
 1068                 vrecycle(ap->a_vp);
 1069         return (0);
 1070 }
 1071 
 1072 #if 0
 1073 struct vop_reclaim_args {
 1074         struct vop_generic_args a_gen;
 1075         struct vnode *a_vp;
 1076         struct thread *a_td;
 1077 };
 1078 #endif
 1079 
 1080 static int
 1081 mqfs_reclaim(struct vop_reclaim_args *ap)
 1082 {
 1083         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_vp->v_mount);
 1084         struct vnode *vp = ap->a_vp;
 1085         struct mqfs_node *pn;
 1086         struct mqfs_vdata *vd;
 1087 
 1088         vd = vp->v_data;
 1089         pn = vd->mv_node;
 1090         sx_xlock(&mqfs->mi_lock);
 1091         vp->v_data = NULL;
 1092         LIST_REMOVE(vd, mv_link);
 1093         uma_zfree(mvdata_zone, vd);
 1094         mqnode_release(pn);
 1095         sx_xunlock(&mqfs->mi_lock);
 1096         return (0);
 1097 }
 1098 
 1099 #if 0
 1100 struct vop_open_args {
 1101         struct vop_generic_args a_gen;
 1102         struct vnode *a_vp;
 1103         int a_mode;
 1104         struct ucred *a_cred;
 1105         struct thread *a_td;
 1106         struct file *a_fp;
 1107 };
 1108 #endif
 1109 
 1110 static int
 1111 mqfs_open(struct vop_open_args *ap)
 1112 {
 1113         return (0);
 1114 }
 1115 
 1116 #if 0
 1117 struct vop_close_args {
 1118         struct vop_generic_args a_gen;
 1119         struct vnode *a_vp;
 1120         int a_fflag;
 1121         struct ucred *a_cred;
 1122         struct thread *a_td;
 1123 };
 1124 #endif
 1125 
 1126 static int
 1127 mqfs_close(struct vop_close_args *ap)
 1128 {
 1129         return (0);
 1130 }
 1131 
 1132 #if 0
 1133 struct vop_access_args {
 1134         struct vop_generic_args a_gen;
 1135         struct vnode *a_vp;
 1136         accmode_t a_accmode;
 1137         struct ucred *a_cred;
 1138         struct thread *a_td;
 1139 };
 1140 #endif
 1141 
 1142 /*
 1143  * Verify permissions
 1144  */
 1145 static int
 1146 mqfs_access(struct vop_access_args *ap)
 1147 {
 1148         struct vnode *vp = ap->a_vp;
 1149         struct vattr vattr;
 1150         int error;
 1151 
 1152         error = VOP_GETATTR(vp, &vattr, ap->a_cred);
 1153         if (error)
 1154                 return (error);
 1155         error = vaccess(vp->v_type, vattr.va_mode, vattr.va_uid,
 1156             vattr.va_gid, ap->a_accmode, ap->a_cred, NULL);
 1157         return (error);
 1158 }
 1159 
 1160 #if 0
 1161 struct vop_getattr_args {
 1162         struct vop_generic_args a_gen;
 1163         struct vnode *a_vp;
 1164         struct vattr *a_vap;
 1165         struct ucred *a_cred;
 1166 };
 1167 #endif
 1168 
 1169 /*
 1170  * Get file attributes
 1171  */
 1172 static int
 1173 mqfs_getattr(struct vop_getattr_args *ap)
 1174 {
 1175         struct vnode *vp = ap->a_vp;
 1176         struct mqfs_node *pn = VTON(vp);
 1177         struct vattr *vap = ap->a_vap;
 1178         int error = 0;
 1179 
 1180         vap->va_type = vp->v_type;
 1181         vap->va_mode = pn->mn_mode;
 1182         vap->va_nlink = 1;
 1183         vap->va_uid = pn->mn_uid;
 1184         vap->va_gid = pn->mn_gid;
 1185         vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
 1186         vap->va_fileid = pn->mn_fileno;
 1187         vap->va_size = 0;
 1188         vap->va_blocksize = PAGE_SIZE;
 1189         vap->va_bytes = vap->va_size = 0;
 1190         vap->va_atime = pn->mn_atime;
 1191         vap->va_mtime = pn->mn_mtime;
 1192         vap->va_ctime = pn->mn_ctime;
 1193         vap->va_birthtime = pn->mn_birth;
 1194         vap->va_gen = 0;
 1195         vap->va_flags = 0;
 1196         vap->va_rdev = NODEV;
 1197         vap->va_bytes = 0;
 1198         vap->va_filerev = 0;
 1199         return (error);
 1200 }
 1201 
 1202 #if 0
 1203 struct vop_setattr_args {
 1204         struct vop_generic_args a_gen;
 1205         struct vnode *a_vp;
 1206         struct vattr *a_vap;
 1207         struct ucred *a_cred;
 1208 };
 1209 #endif
 1210 /*
 1211  * Set attributes
 1212  */
 1213 static int
 1214 mqfs_setattr(struct vop_setattr_args *ap)
 1215 {
 1216         struct mqfs_node *pn;
 1217         struct vattr *vap;
 1218         struct vnode *vp;
 1219         struct thread *td;
 1220         int c, error;
 1221         uid_t uid;
 1222         gid_t gid;
 1223 
 1224         td = curthread;
 1225         vap = ap->a_vap;
 1226         vp = ap->a_vp;
 1227         if ((vap->va_type != VNON) ||
 1228             (vap->va_nlink != VNOVAL) ||
 1229             (vap->va_fsid != VNOVAL) ||
 1230             (vap->va_fileid != VNOVAL) ||
 1231             (vap->va_blocksize != VNOVAL) ||
 1232             (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
 1233             (vap->va_rdev != VNOVAL) ||
 1234             ((int)vap->va_bytes != VNOVAL) ||
 1235             (vap->va_gen != VNOVAL)) {
 1236                 return (EINVAL);
 1237         }
 1238 
 1239         pn = VTON(vp);
 1240 
 1241         error = c = 0;
 1242         if (vap->va_uid == (uid_t)VNOVAL)
 1243                 uid = pn->mn_uid;
 1244         else
 1245                 uid = vap->va_uid;
 1246         if (vap->va_gid == (gid_t)VNOVAL)
 1247                 gid = pn->mn_gid;
 1248         else
 1249                 gid = vap->va_gid;
 1250 
 1251         if (uid != pn->mn_uid || gid != pn->mn_gid) {
 1252                 /*
 1253                  * To modify the ownership of a file, must possess VADMIN
 1254                  * for that file.
 1255                  */
 1256                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)))
 1257                         return (error);
 1258 
 1259                 /*
 1260                  * XXXRW: Why is there a privilege check here: shouldn't the
 1261                  * check in VOP_ACCESS() be enough?  Also, are the group bits
 1262                  * below definitely right?
 1263                  */
 1264                 if (((ap->a_cred->cr_uid != pn->mn_uid) || uid != pn->mn_uid ||
 1265                     (gid != pn->mn_gid && !groupmember(gid, ap->a_cred))) &&
 1266                     (error = priv_check(td, PRIV_MQ_ADMIN)) != 0)
 1267                         return (error);
 1268                 pn->mn_uid = uid;
 1269                 pn->mn_gid = gid;
 1270                 c = 1;
 1271         }
 1272 
 1273         if (vap->va_mode != (mode_t)VNOVAL) {
 1274                 if ((ap->a_cred->cr_uid != pn->mn_uid) &&
 1275                     (error = priv_check(td, PRIV_MQ_ADMIN)))
 1276                         return (error);
 1277                 pn->mn_mode = vap->va_mode;
 1278                 c = 1;
 1279         }
 1280 
 1281         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
 1282                 /* See the comment in ufs_vnops::ufs_setattr(). */
 1283                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)) &&
 1284                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
 1285                     (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, td))))
 1286                         return (error);
 1287                 if (vap->va_atime.tv_sec != VNOVAL) {
 1288                         pn->mn_atime = vap->va_atime;
 1289                 }
 1290                 if (vap->va_mtime.tv_sec != VNOVAL) {
 1291                         pn->mn_mtime = vap->va_mtime;
 1292                 }
 1293                 c = 1;
 1294         }
 1295         if (c) {
 1296                 vfs_timestamp(&pn->mn_ctime);
 1297         }
 1298         return (0);
 1299 }
 1300 
 1301 #if 0
 1302 struct vop_read_args {
 1303         struct vop_generic_args a_gen;
 1304         struct vnode *a_vp;
 1305         struct uio *a_uio;
 1306         int a_ioflag;
 1307         struct ucred *a_cred;
 1308 };
 1309 #endif
 1310 
 1311 /*
 1312  * Read from a file
 1313  */
 1314 static int
 1315 mqfs_read(struct vop_read_args *ap)
 1316 {
 1317         char buf[80];
 1318         struct vnode *vp = ap->a_vp;
 1319         struct uio *uio = ap->a_uio;
 1320         struct mqfs_node *pn;
 1321         struct mqueue *mq;
 1322         int len, error;
 1323 
 1324         if (vp->v_type != VREG)
 1325                 return (EINVAL);
 1326 
 1327         pn = VTON(vp);
 1328         mq = VTOMQ(vp);
 1329         snprintf(buf, sizeof(buf),
 1330                 "QSIZE:%-10ld MAXMSG:%-10ld CURMSG:%-10ld MSGSIZE:%-10ld\n",
 1331                 mq->mq_totalbytes,
 1332                 mq->mq_maxmsg,
 1333                 mq->mq_curmsgs,
 1334                 mq->mq_msgsize);
 1335         buf[sizeof(buf)-1] = '\0';
 1336         len = strlen(buf);
 1337         error = uiomove_frombuf(buf, len, uio);
 1338         return (error);
 1339 }
 1340 
 1341 #if 0
 1342 struct vop_readdir_args {
 1343         struct vop_generic_args a_gen;
 1344         struct vnode *a_vp;
 1345         struct uio *a_uio;
 1346         struct ucred *a_cred;
 1347         int *a_eofflag;
 1348         int *a_ncookies;
 1349         u_long **a_cookies;
 1350 };
 1351 #endif
 1352 
 1353 /*
 1354  * Return directory entries.
 1355  */
 1356 static int
 1357 mqfs_readdir(struct vop_readdir_args *ap)
 1358 {
 1359         struct vnode *vp;
 1360         struct mqfs_info *mi;
 1361         struct mqfs_node *pd;
 1362         struct mqfs_node *pn;
 1363         struct dirent entry;
 1364         struct uio *uio;
 1365         int *tmp_ncookies = NULL;
 1366         off_t offset;
 1367         int error, i;
 1368 
 1369         vp = ap->a_vp;
 1370         mi = VFSTOMQFS(vp->v_mount);
 1371         pd = VTON(vp);
 1372         uio = ap->a_uio;
 1373 
 1374         if (vp->v_type != VDIR)
 1375                 return (ENOTDIR);
 1376 
 1377         if (uio->uio_offset < 0)
 1378                 return (EINVAL);
 1379 
 1380         if (ap->a_ncookies != NULL) {
 1381                 tmp_ncookies = ap->a_ncookies;
 1382                 *ap->a_ncookies = 0;
 1383                 ap->a_ncookies = NULL;
 1384         }
 1385 
 1386         error = 0;
 1387         offset = 0;
 1388 
 1389         sx_xlock(&mi->mi_lock);
 1390 
 1391         LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
 1392                 entry.d_reclen = sizeof(entry);
 1393                 if (!pn->mn_fileno)
 1394                         mqfs_fileno_alloc(mi, pn);
 1395                 entry.d_fileno = pn->mn_fileno;
 1396                 for (i = 0; i < MQFS_NAMELEN - 1 && pn->mn_name[i] != '\0'; ++i)
 1397                         entry.d_name[i] = pn->mn_name[i];
 1398                 entry.d_name[i] = 0;
 1399                 entry.d_namlen = i;
 1400                 switch (pn->mn_type) {
 1401                 case mqfstype_root:
 1402                 case mqfstype_dir:
 1403                 case mqfstype_this:
 1404                 case mqfstype_parent:
 1405                         entry.d_type = DT_DIR;
 1406                         break;
 1407                 case mqfstype_file:
 1408                         entry.d_type = DT_REG;
 1409                         break;
 1410                 case mqfstype_symlink:
 1411                         entry.d_type = DT_LNK;
 1412                         break;
 1413                 default:
 1414                         panic("%s has unexpected node type: %d", pn->mn_name,
 1415                                 pn->mn_type);
 1416                 }
 1417                 if (entry.d_reclen > uio->uio_resid)
 1418                         break;
 1419                 if (offset >= uio->uio_offset) {
 1420                         error = vfs_read_dirent(ap, &entry, offset);
 1421                         if (error)
 1422                                 break;
 1423                 }
 1424                 offset += entry.d_reclen;
 1425         }
 1426         sx_xunlock(&mi->mi_lock);
 1427 
 1428         uio->uio_offset = offset;
 1429 
 1430         if (tmp_ncookies != NULL)
 1431                 ap->a_ncookies = tmp_ncookies;
 1432 
 1433         return (error);
 1434 }
 1435 
 1436 #ifdef notyet
 1437 
 1438 #if 0
 1439 struct vop_mkdir_args {
 1440         struct vnode *a_dvp;
 1441         struvt vnode **a_vpp;
 1442         struvt componentname *a_cnp;
 1443         struct vattr *a_vap;
 1444 };
 1445 #endif
 1446 
 1447 /*
 1448  * Create a directory.
 1449  */
 1450 static int
 1451 mqfs_mkdir(struct vop_mkdir_args *ap)
 1452 {
 1453         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
 1454         struct componentname *cnp = ap->a_cnp;
 1455         struct mqfs_node *pd = VTON(ap->a_dvp);
 1456         struct mqfs_node *pn;
 1457         int error;
 1458 
 1459         if (pd->mn_type != mqfstype_root && pd->mn_type != mqfstype_dir)
 1460                 return (ENOTDIR);
 1461         sx_xlock(&mqfs->mi_lock);
 1462         if ((cnp->cn_flags & HASBUF) == 0)
 1463                 panic("%s: no name", __func__);
 1464         pn = mqfs_create_dir(pd, cnp->cn_nameptr, cnp->cn_namelen,
 1465                 ap->a_vap->cn_cred, ap->a_vap->va_mode);
 1466         if (pn != NULL)
 1467                 mqnode_addref(pn);
 1468         sx_xunlock(&mqfs->mi_lock);
 1469         if (pn == NULL) {
 1470                 error = ENOSPC;
 1471         } else {
 1472                 error = mqfs_allocv(ap->a_dvp->v_mount, ap->a_vpp, pn);
 1473                 mqnode_release(pn);
 1474         }
 1475         return (error);
 1476 }
 1477 
 1478 #if 0
 1479 struct vop_rmdir_args {
 1480         struct vnode *a_dvp;
 1481         struct vnode *a_vp;
 1482         struct componentname *a_cnp;
 1483 };
 1484 #endif
 1485 
 1486 /*
 1487  * Remove a directory.
 1488  */
 1489 static int
 1490 mqfs_rmdir(struct vop_rmdir_args *ap)
 1491 {
 1492         struct mqfs_info *mqfs = VFSTOMQFS(ap->a_dvp->v_mount);
 1493         struct mqfs_node *pn = VTON(ap->a_vp);
 1494         struct mqfs_node *pt;
 1495 
 1496         if (pn->mn_type != mqfstype_dir)
 1497                 return (ENOTDIR);
 1498 
 1499         sx_xlock(&mqfs->mi_lock);
 1500         if (pn->mn_deleted) {
 1501                 sx_xunlock(&mqfs->mi_lock);
 1502                 return (ENOENT);
 1503         }
 1504 
 1505         pt = LIST_FIRST(&pn->mn_children);
 1506         pt = LIST_NEXT(pt, mn_sibling);
 1507         pt = LIST_NEXT(pt, mn_sibling);
 1508         if (pt != NULL) {
 1509                 sx_xunlock(&mqfs->mi_lock);
 1510                 return (ENOTEMPTY);
 1511         }
 1512         pt = pn->mn_parent;
 1513         pn->mn_parent = NULL;
 1514         pn->mn_deleted = 1;
 1515         LIST_REMOVE(pn, mn_sibling);
 1516         mqnode_release(pn);
 1517         mqnode_release(pt);
 1518         sx_xunlock(&mqfs->mi_lock);
 1519         cache_purge(ap->a_vp);
 1520         return (0);
 1521 }
 1522 
 1523 #endif /* notyet */
 1524 
 1525 /*
 1526  * Allocate a message queue
 1527  */
 1528 static struct mqueue *
 1529 mqueue_alloc(const struct mq_attr *attr)
 1530 {
 1531         struct mqueue *mq;
 1532 
 1533         if (curmq >= maxmq)
 1534                 return (NULL);
 1535         mq = uma_zalloc(mqueue_zone, M_WAITOK | M_ZERO);
 1536         TAILQ_INIT(&mq->mq_msgq);
 1537         if (attr != NULL) {
 1538                 mq->mq_maxmsg = attr->mq_maxmsg;
 1539                 mq->mq_msgsize = attr->mq_msgsize;
 1540         } else {
 1541                 mq->mq_maxmsg = default_maxmsg;
 1542                 mq->mq_msgsize = default_msgsize;
 1543         }
 1544         mtx_init(&mq->mq_mutex, "mqueue lock", NULL, MTX_DEF);
 1545         knlist_init_mtx(&mq->mq_rsel.si_note, &mq->mq_mutex);
 1546         knlist_init_mtx(&mq->mq_wsel.si_note, &mq->mq_mutex);
 1547         atomic_add_int(&curmq, 1);
 1548         return (mq);
 1549 }
 1550 
 1551 /*
 1552  * Destroy a message queue
 1553  */
 1554 static void
 1555 mqueue_free(struct mqueue *mq)
 1556 {
 1557         struct mqueue_msg *msg;
 1558 
 1559         while ((msg = TAILQ_FIRST(&mq->mq_msgq)) != NULL) {
 1560                 TAILQ_REMOVE(&mq->mq_msgq, msg, msg_link);
 1561                 free(msg, M_MQUEUEDATA);
 1562         }
 1563 
 1564         mtx_destroy(&mq->mq_mutex);
 1565         seldrain(&mq->mq_rsel);
 1566         seldrain(&mq->mq_wsel);
 1567         knlist_destroy(&mq->mq_rsel.si_note);
 1568         knlist_destroy(&mq->mq_wsel.si_note);
 1569         uma_zfree(mqueue_zone, mq);
 1570         atomic_add_int(&curmq, -1);
 1571 }
 1572 
 1573 /*
 1574  * Load a message from user space
 1575  */
 1576 static struct mqueue_msg *
 1577 mqueue_loadmsg(const char *msg_ptr, size_t msg_size, int msg_prio)
 1578 {
 1579         struct mqueue_msg *msg;
 1580         size_t len;
 1581         int error;
 1582 
 1583         len = sizeof(struct mqueue_msg) + msg_size;
 1584         msg = malloc(len, M_MQUEUEDATA, M_WAITOK);
 1585         error = copyin(msg_ptr, ((char *)msg) + sizeof(struct mqueue_msg),
 1586             msg_size);
 1587         if (error) {
 1588                 free(msg, M_MQUEUEDATA);
 1589                 msg = NULL;
 1590         } else {
 1591                 msg->msg_size = msg_size;
 1592                 msg->msg_prio = msg_prio;
 1593         }
 1594         return (msg);
 1595 }
 1596 
 1597 /*
 1598  * Save a message to user space
 1599  */
 1600 static int
 1601 mqueue_savemsg(struct mqueue_msg *msg, char *msg_ptr, int *msg_prio)
 1602 {
 1603         int error;
 1604 
 1605         error = copyout(((char *)msg) + sizeof(*msg), msg_ptr,
 1606                 msg->msg_size);
 1607         if (error == 0 && msg_prio != NULL)
 1608                 error = copyout(&msg->msg_prio, msg_prio, sizeof(int));
 1609         return (error);
 1610 }
 1611 
 1612 /*
 1613  * Free a message's memory
 1614  */
 1615 static __inline void
 1616 mqueue_freemsg(struct mqueue_msg *msg)
 1617 {
 1618         free(msg, M_MQUEUEDATA);
 1619 }
 1620 
 1621 /*
 1622  * Send a message. if waitok is false, thread will not be
 1623  * blocked if there is no data in queue, otherwise, absolute
 1624  * time will be checked.
 1625  */
 1626 int
 1627 mqueue_send(struct mqueue *mq, const char *msg_ptr,
 1628         size_t msg_len, unsigned msg_prio, int waitok,
 1629         const struct timespec *abs_timeout)
 1630 {
 1631         struct mqueue_msg *msg;
 1632         struct timespec ts, ts2;
 1633         struct timeval tv;
 1634         int error;
 1635 
 1636         if (msg_prio >= MQ_PRIO_MAX)
 1637                 return (EINVAL);
 1638         if (msg_len > mq->mq_msgsize)
 1639                 return (EMSGSIZE);
 1640         msg = mqueue_loadmsg(msg_ptr, msg_len, msg_prio);
 1641         if (msg == NULL)
 1642                 return (EFAULT);
 1643 
 1644         /* O_NONBLOCK case */
 1645         if (!waitok) {
 1646                 error = _mqueue_send(mq, msg, -1);
 1647                 if (error)
 1648                         goto bad;
 1649                 return (0);
 1650         }
 1651 
 1652         /* we allow a null timeout (wait forever) */
 1653         if (abs_timeout == NULL) {
 1654                 error = _mqueue_send(mq, msg, 0);
 1655                 if (error)
 1656                         goto bad;
 1657                 return (0);
 1658         }
 1659 
 1660         /* send it before checking time */
 1661         error = _mqueue_send(mq, msg, -1);
 1662         if (error == 0)
 1663                 return (0);
 1664 
 1665         if (error != EAGAIN)
 1666                 goto bad;
 1667 
 1668         if (abs_timeout->tv_nsec >= 1000000000 || abs_timeout->tv_nsec < 0) {
 1669                 error = EINVAL;
 1670                 goto bad;
 1671         }
 1672         for (;;) {
 1673                 ts2 = *abs_timeout;
 1674                 getnanotime(&ts);
 1675                 timespecsub(&ts2, &ts);
 1676                 if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
 1677                         error = ETIMEDOUT;
 1678                         break;
 1679                 }
 1680                 TIMESPEC_TO_TIMEVAL(&tv, &ts2);
 1681                 error = _mqueue_send(mq, msg, tvtohz(&tv));
 1682                 if (error != ETIMEDOUT)
 1683                         break;
 1684         }
 1685         if (error == 0)
 1686                 return (0);
 1687 bad:
 1688         mqueue_freemsg(msg);
 1689         return (error);
 1690 }
 1691 
 1692 /*
 1693  * Common routine to send a message
 1694  */
 1695 static int
 1696 _mqueue_send(struct mqueue *mq, struct mqueue_msg *msg, int timo)
 1697 {       
 1698         struct mqueue_msg *msg2;
 1699         int error = 0;
 1700 
 1701         mtx_lock(&mq->mq_mutex);
 1702         while (mq->mq_curmsgs >= mq->mq_maxmsg && error == 0) {
 1703                 if (timo < 0) {
 1704                         mtx_unlock(&mq->mq_mutex);
 1705                         return (EAGAIN);
 1706                 }
 1707                 mq->mq_senders++;
 1708                 error = msleep(&mq->mq_senders, &mq->mq_mutex,
 1709                             PCATCH, "mqsend", timo);
 1710                 mq->mq_senders--;
 1711                 if (error == EAGAIN)
 1712                         error = ETIMEDOUT;
 1713         }
 1714         if (mq->mq_curmsgs >= mq->mq_maxmsg) {
 1715                 mtx_unlock(&mq->mq_mutex);
 1716                 return (error);
 1717         }
 1718         error = 0;
 1719         if (TAILQ_EMPTY(&mq->mq_msgq)) {
 1720                 TAILQ_INSERT_HEAD(&mq->mq_msgq, msg, msg_link);
 1721         } else {
 1722                 if (msg->msg_prio <= TAILQ_LAST(&mq->mq_msgq, msgq)->msg_prio) {
 1723                         TAILQ_INSERT_TAIL(&mq->mq_msgq, msg, msg_link);
 1724                 } else {
 1725                         TAILQ_FOREACH(msg2, &mq->mq_msgq, msg_link) {
 1726                                 if (msg2->msg_prio < msg->msg_prio)
 1727                                         break;
 1728                         }
 1729                         TAILQ_INSERT_BEFORE(msg2, msg, msg_link);
 1730                 }
 1731         }
 1732         mq->mq_curmsgs++;
 1733         mq->mq_totalbytes += msg->msg_size;
 1734         if (mq->mq_receivers)
 1735                 wakeup_one(&mq->mq_receivers);
 1736         else if (mq->mq_notifier != NULL)
 1737                 mqueue_send_notification(mq);
 1738         if (mq->mq_flags & MQ_RSEL) {
 1739                 mq->mq_flags &= ~MQ_RSEL;
 1740                 selwakeup(&mq->mq_rsel);
 1741         }
 1742         KNOTE_LOCKED(&mq->mq_rsel.si_note, 0);
 1743         mtx_unlock(&mq->mq_mutex);
 1744         return (0);
 1745 }
 1746 
 1747 /*
 1748  * Send realtime a signal to process which registered itself
 1749  * successfully by mq_notify.
 1750  */
 1751 static void
 1752 mqueue_send_notification(struct mqueue *mq)
 1753 {
 1754         struct mqueue_notifier *nt;
 1755         struct thread *td;
 1756         struct proc *p;
 1757         int error;
 1758 
 1759         mtx_assert(&mq->mq_mutex, MA_OWNED);
 1760         nt = mq->mq_notifier;
 1761         if (nt->nt_sigev.sigev_notify != SIGEV_NONE) {
 1762                 p = nt->nt_proc;
 1763                 error = sigev_findtd(p, &nt->nt_sigev, &td);
 1764                 if (error) {
 1765                         mq->mq_notifier = NULL;
 1766                         return;
 1767                 }
 1768                 if (!KSI_ONQ(&nt->nt_ksi)) {
 1769                         ksiginfo_set_sigev(&nt->nt_ksi, &nt->nt_sigev);
 1770                         tdsendsignal(p, td, nt->nt_ksi.ksi_signo, &nt->nt_ksi);
 1771                 }
 1772                 PROC_UNLOCK(p);
 1773         }
 1774         mq->mq_notifier = NULL;
 1775 }
 1776 
 1777 /*
 1778  * Get a message. if waitok is false, thread will not be
 1779  * blocked if there is no data in queue, otherwise, absolute
 1780  * time will be checked.
 1781  */
 1782 int
 1783 mqueue_receive(struct mqueue *mq, char *msg_ptr,
 1784         size_t msg_len, unsigned *msg_prio, int waitok,
 1785         const struct timespec *abs_timeout)
 1786 {
 1787         struct mqueue_msg *msg;
 1788         struct timespec ts, ts2;
 1789         struct timeval tv;
 1790         int error;
 1791 
 1792         if (msg_len < mq->mq_msgsize)
 1793                 return (EMSGSIZE);
 1794 
 1795         /* O_NONBLOCK case */
 1796         if (!waitok) {
 1797                 error = _mqueue_recv(mq, &msg, -1);
 1798                 if (error)
 1799                         return (error);
 1800                 goto received;
 1801         }
 1802 
 1803         /* we allow a null timeout (wait forever). */
 1804         if (abs_timeout == NULL) {
 1805                 error = _mqueue_recv(mq, &msg, 0);
 1806                 if (error)
 1807                         return (error);
 1808                 goto received;
 1809         }
 1810 
 1811         /* try to get a message before checking time */
 1812         error = _mqueue_recv(mq, &msg, -1);
 1813         if (error == 0)
 1814                 goto received;
 1815 
 1816         if (error != EAGAIN)
 1817                 return (error);
 1818 
 1819         if (abs_timeout->tv_nsec >= 1000000000 || abs_timeout->tv_nsec < 0) {
 1820                 error = EINVAL;
 1821                 return (error);
 1822         }
 1823 
 1824         for (;;) {
 1825                 ts2 = *abs_timeout;
 1826                 getnanotime(&ts);
 1827                 timespecsub(&ts2, &ts);
 1828                 if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
 1829                         error = ETIMEDOUT;
 1830                         return (error);
 1831                 }
 1832                 TIMESPEC_TO_TIMEVAL(&tv, &ts2);
 1833                 error = _mqueue_recv(mq, &msg, tvtohz(&tv));
 1834                 if (error == 0)
 1835                         break;
 1836                 if (error != ETIMEDOUT)
 1837                         return (error);
 1838         }
 1839 
 1840 received:
 1841         error = mqueue_savemsg(msg, msg_ptr, msg_prio);
 1842         if (error == 0) {
 1843                 curthread->td_retval[0] = msg->msg_size;
 1844                 curthread->td_retval[1] = 0;
 1845         }
 1846         mqueue_freemsg(msg);
 1847         return (error);
 1848 }
 1849 
 1850 /*
 1851  * Common routine to receive a message
 1852  */
 1853 static int
 1854 _mqueue_recv(struct mqueue *mq, struct mqueue_msg **msg, int timo)
 1855 {       
 1856         int error = 0;
 1857         
 1858         mtx_lock(&mq->mq_mutex);
 1859         while ((*msg = TAILQ_FIRST(&mq->mq_msgq)) == NULL && error == 0) {
 1860                 if (timo < 0) {
 1861                         mtx_unlock(&mq->mq_mutex);
 1862                         return (EAGAIN);
 1863                 }
 1864                 mq->mq_receivers++;
 1865                 error = msleep(&mq->mq_receivers, &mq->mq_mutex,
 1866                             PCATCH, "mqrecv", timo);
 1867                 mq->mq_receivers--;
 1868                 if (error == EAGAIN)
 1869                         error = ETIMEDOUT;
 1870         }
 1871         if (*msg != NULL) {
 1872                 error = 0;
 1873                 TAILQ_REMOVE(&mq->mq_msgq, *msg, msg_link);
 1874                 mq->mq_curmsgs--;
 1875                 mq->mq_totalbytes -= (*msg)->msg_size;
 1876                 if (mq->mq_senders)
 1877                         wakeup_one(&mq->mq_senders);
 1878                 if (mq->mq_flags & MQ_WSEL) {
 1879                         mq->mq_flags &= ~MQ_WSEL;
 1880                         selwakeup(&mq->mq_wsel);
 1881                 }
 1882                 KNOTE_LOCKED(&mq->mq_wsel.si_note, 0);
 1883         }
 1884         if (mq->mq_notifier != NULL && mq->mq_receivers == 0 &&
 1885             !TAILQ_EMPTY(&mq->mq_msgq)) {
 1886                 mqueue_send_notification(mq);
 1887         }
 1888         mtx_unlock(&mq->mq_mutex);
 1889         return (error);
 1890 }
 1891 
 1892 static __inline struct mqueue_notifier *
 1893 notifier_alloc(void)
 1894 {
 1895         return (uma_zalloc(mqnoti_zone, M_WAITOK | M_ZERO));
 1896 }
 1897 
 1898 static __inline void
 1899 notifier_free(struct mqueue_notifier *p)
 1900 {
 1901         uma_zfree(mqnoti_zone, p);
 1902 }
 1903 
 1904 static struct mqueue_notifier *
 1905 notifier_search(struct proc *p, int fd)
 1906 {
 1907         struct mqueue_notifier *nt;
 1908 
 1909         LIST_FOREACH(nt, &p->p_mqnotifier, nt_link) {
 1910                 if (nt->nt_ksi.ksi_mqd == fd)
 1911                         break;
 1912         }
 1913         return (nt);
 1914 }
 1915 
 1916 static __inline void
 1917 notifier_insert(struct proc *p, struct mqueue_notifier *nt)
 1918 {
 1919         LIST_INSERT_HEAD(&p->p_mqnotifier, nt, nt_link);
 1920 }
 1921 
 1922 static __inline void
 1923 notifier_delete(struct proc *p, struct mqueue_notifier *nt)
 1924 {
 1925         LIST_REMOVE(nt, nt_link);
 1926         notifier_free(nt);
 1927 }
 1928 
 1929 static void
 1930 notifier_remove(struct proc *p, struct mqueue *mq, int fd)
 1931 {
 1932         struct mqueue_notifier *nt;
 1933 
 1934         mtx_assert(&mq->mq_mutex, MA_OWNED);
 1935         PROC_LOCK(p);
 1936         nt = notifier_search(p, fd);
 1937         if (nt != NULL) {
 1938                 if (mq->mq_notifier == nt)
 1939                         mq->mq_notifier = NULL;
 1940                 sigqueue_take(&nt->nt_ksi);
 1941                 notifier_delete(p, nt);
 1942         }
 1943         PROC_UNLOCK(p);
 1944 }
 1945 
 1946 static int
 1947 kern_kmq_open(struct thread *td, const char *upath, int flags, mode_t mode,
 1948     const struct mq_attr *attr)
 1949 {
 1950         char path[MQFS_NAMELEN + 1];
 1951         struct mqfs_node *pn;
 1952         struct filedesc *fdp;
 1953         struct file *fp;
 1954         struct mqueue *mq;
 1955         int fd, error, len, cmode;
 1956 
 1957         fdp = td->td_proc->p_fd;
 1958         cmode = (((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT);
 1959         mq = NULL;
 1960         if ((flags & O_CREAT) != 0 && attr != NULL) {
 1961                 if (attr->mq_maxmsg <= 0 || attr->mq_maxmsg > maxmsg)
 1962                         return (EINVAL);
 1963                 if (attr->mq_msgsize <= 0 || attr->mq_msgsize > maxmsgsize)
 1964                         return (EINVAL);
 1965         }
 1966 
 1967         error = copyinstr(upath, path, MQFS_NAMELEN + 1, NULL);
 1968         if (error)
 1969                 return (error);
 1970 
 1971         /*
 1972          * The first character of name must be a slash  (/) character
 1973          * and the remaining characters of name cannot include any slash
 1974          * characters. 
 1975          */
 1976         len = strlen(path);
 1977         if (len < 2 || path[0] != '/' || strchr(path + 1, '/') != NULL)
 1978                 return (EINVAL);
 1979 
 1980         error = falloc(td, &fp, &fd, O_CLOEXEC);
 1981         if (error)
 1982                 return (error);
 1983 
 1984         sx_xlock(&mqfs_data.mi_lock);
 1985         pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
 1986         if (pn == NULL) {
 1987                 if (!(flags & O_CREAT)) {
 1988                         error = ENOENT;
 1989                 } else {
 1990                         mq = mqueue_alloc(attr);
 1991                         if (mq == NULL) {
 1992                                 error = ENFILE;
 1993                         } else {
 1994                                 pn = mqfs_create_file(mqfs_data.mi_root,
 1995                                          path + 1, len - 1, td->td_ucred,
 1996                                          cmode);
 1997                                 if (pn == NULL) {
 1998                                         error = ENOSPC;
 1999                                         mqueue_free(mq);
 2000                                 }
 2001                         }
 2002                 }
 2003 
 2004                 if (error == 0) {
 2005                         pn->mn_data = mq;
 2006                 }
 2007         } else {
 2008                 if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL)) {
 2009                         error = EEXIST;
 2010                 } else {
 2011                         accmode_t accmode = 0;
 2012 
 2013                         if (flags & FREAD)
 2014                                 accmode |= VREAD;
 2015                         if (flags & FWRITE)
 2016                                 accmode |= VWRITE;
 2017                         error = vaccess(VREG, pn->mn_mode, pn->mn_uid,
 2018                                     pn->mn_gid, accmode, td->td_ucred, NULL);
 2019                 }
 2020         }
 2021 
 2022         if (error) {
 2023                 sx_xunlock(&mqfs_data.mi_lock);
 2024                 fdclose(fdp, fp, fd, td);
 2025                 fdrop(fp, td);
 2026                 return (error);
 2027         }
 2028 
 2029         mqnode_addref(pn);
 2030         sx_xunlock(&mqfs_data.mi_lock);
 2031 
 2032         finit(fp, flags & (FREAD | FWRITE | O_NONBLOCK), DTYPE_MQUEUE, pn,
 2033             &mqueueops);
 2034 
 2035         td->td_retval[0] = fd;
 2036         fdrop(fp, td);
 2037         return (0);
 2038 }
 2039 
 2040 /*
 2041  * Syscall to open a message queue.
 2042  */
 2043 int
 2044 sys_kmq_open(struct thread *td, struct kmq_open_args *uap)
 2045 {
 2046         struct mq_attr attr;
 2047         int flags, error;
 2048 
 2049         if ((uap->flags & O_ACCMODE) == O_ACCMODE || uap->flags & O_EXEC)
 2050                 return (EINVAL);
 2051         flags = FFLAGS(uap->flags);
 2052         if ((flags & O_CREAT) != 0 && uap->attr != NULL) {
 2053                 error = copyin(uap->attr, &attr, sizeof(attr));
 2054                 if (error)
 2055                         return (error);
 2056         }
 2057         return (kern_kmq_open(td, uap->path, flags, uap->mode,
 2058             uap->attr != NULL ? &attr : NULL));
 2059 }
 2060 
 2061 /*
 2062  * Syscall to unlink a message queue.
 2063  */
 2064 int
 2065 sys_kmq_unlink(struct thread *td, struct kmq_unlink_args *uap)
 2066 {
 2067         char path[MQFS_NAMELEN+1];
 2068         struct mqfs_node *pn;
 2069         int error, len;
 2070 
 2071         error = copyinstr(uap->path, path, MQFS_NAMELEN + 1, NULL);
 2072         if (error)
 2073                 return (error);
 2074 
 2075         len = strlen(path);
 2076         if (len < 2 || path[0] != '/' || strchr(path + 1, '/') != NULL)
 2077                 return (EINVAL);
 2078 
 2079         sx_xlock(&mqfs_data.mi_lock);
 2080         pn = mqfs_search(mqfs_data.mi_root, path + 1, len - 1);
 2081         if (pn != NULL)
 2082                 error = do_unlink(pn, td->td_ucred);
 2083         else
 2084                 error = ENOENT;
 2085         sx_xunlock(&mqfs_data.mi_lock);
 2086         return (error);
 2087 }
 2088 
 2089 typedef int (*_fgetf)(struct thread *, int, cap_rights_t *, struct file **);
 2090 
 2091 /*
 2092  * Get message queue by giving file slot
 2093  */
 2094 static int
 2095 _getmq(struct thread *td, int fd, cap_rights_t *rightsp, _fgetf func,
 2096        struct file **fpp, struct mqfs_node **ppn, struct mqueue **pmq)
 2097 {
 2098         struct mqfs_node *pn;
 2099         int error;
 2100 
 2101         error = func(td, fd, rightsp, fpp);
 2102         if (error)
 2103                 return (error);
 2104         if (&mqueueops != (*fpp)->f_ops) {
 2105                 fdrop(*fpp, td);
 2106                 return (EBADF);
 2107         }
 2108         pn = (*fpp)->f_data;
 2109         if (ppn)
 2110                 *ppn = pn;
 2111         if (pmq)
 2112                 *pmq = pn->mn_data;
 2113         return (0);
 2114 }
 2115 
 2116 static __inline int
 2117 getmq(struct thread *td, int fd, struct file **fpp, struct mqfs_node **ppn,
 2118         struct mqueue **pmq)
 2119 {
 2120         cap_rights_t rights;
 2121 
 2122         return _getmq(td, fd, cap_rights_init(&rights, CAP_EVENT), fget,
 2123             fpp, ppn, pmq);
 2124 }
 2125 
 2126 static __inline int
 2127 getmq_read(struct thread *td, int fd, struct file **fpp,
 2128          struct mqfs_node **ppn, struct mqueue **pmq)
 2129 {
 2130         cap_rights_t rights;
 2131 
 2132         return _getmq(td, fd, cap_rights_init(&rights, CAP_READ), fget_read,
 2133             fpp, ppn, pmq);
 2134 }
 2135 
 2136 static __inline int
 2137 getmq_write(struct thread *td, int fd, struct file **fpp,
 2138         struct mqfs_node **ppn, struct mqueue **pmq)
 2139 {
 2140         cap_rights_t rights;
 2141 
 2142         return _getmq(td, fd, cap_rights_init(&rights, CAP_WRITE), fget_write,
 2143             fpp, ppn, pmq);
 2144 }
 2145 
 2146 static int
 2147 kern_kmq_setattr(struct thread *td, int mqd, const struct mq_attr *attr,
 2148     struct mq_attr *oattr)
 2149 {
 2150         struct mqueue *mq;
 2151         struct file *fp;
 2152         u_int oflag, flag;
 2153         int error;
 2154 
 2155         if (attr != NULL && (attr->mq_flags & ~O_NONBLOCK) != 0)
 2156                 return (EINVAL);
 2157         error = getmq(td, mqd, &fp, NULL, &mq);
 2158         if (error)
 2159                 return (error);
 2160         oattr->mq_maxmsg  = mq->mq_maxmsg;
 2161         oattr->mq_msgsize = mq->mq_msgsize;
 2162         oattr->mq_curmsgs = mq->mq_curmsgs;
 2163         if (attr != NULL) {
 2164                 do {
 2165                         oflag = flag = fp->f_flag;
 2166                         flag &= ~O_NONBLOCK;
 2167                         flag |= (attr->mq_flags & O_NONBLOCK);
 2168                 } while (atomic_cmpset_int(&fp->f_flag, oflag, flag) == 0);
 2169         } else
 2170                 oflag = fp->f_flag;
 2171         oattr->mq_flags = (O_NONBLOCK & oflag);
 2172         fdrop(fp, td);
 2173         return (error);
 2174 }
 2175 
 2176 int
 2177 sys_kmq_setattr(struct thread *td, struct kmq_setattr_args *uap)
 2178 {
 2179         struct mq_attr attr, oattr;
 2180         int error;
 2181 
 2182         if (uap->attr != NULL) {
 2183                 error = copyin(uap->attr, &attr, sizeof(attr));
 2184                 if (error != 0)
 2185                         return (error);
 2186         }
 2187         error = kern_kmq_setattr(td, uap->mqd, uap->attr != NULL ? &attr : NULL,
 2188             &oattr);
 2189         if (error != 0)
 2190                 return (error);
 2191         if (uap->oattr != NULL)
 2192                 error = copyout(&oattr, uap->oattr, sizeof(oattr));
 2193         return (error);
 2194 }
 2195 
 2196 int
 2197 sys_kmq_timedreceive(struct thread *td, struct kmq_timedreceive_args *uap)
 2198 {
 2199         struct mqueue *mq;
 2200         struct file *fp;
 2201         struct timespec *abs_timeout, ets;
 2202         int error;
 2203         int waitok;
 2204 
 2205         error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
 2206         if (error)
 2207                 return (error);
 2208         if (uap->abs_timeout != NULL) {
 2209                 error = copyin(uap->abs_timeout, &ets, sizeof(ets));
 2210                 if (error != 0)
 2211                         return (error);
 2212                 abs_timeout = &ets;
 2213         } else
 2214                 abs_timeout = NULL;
 2215         waitok = !(fp->f_flag & O_NONBLOCK);
 2216         error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
 2217                 uap->msg_prio, waitok, abs_timeout);
 2218         fdrop(fp, td);
 2219         return (error);
 2220 }
 2221 
 2222 int
 2223 sys_kmq_timedsend(struct thread *td, struct kmq_timedsend_args *uap)
 2224 {
 2225         struct mqueue *mq;
 2226         struct file *fp;
 2227         struct timespec *abs_timeout, ets;
 2228         int error, waitok;
 2229 
 2230         error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
 2231         if (error)
 2232                 return (error);
 2233         if (uap->abs_timeout != NULL) {
 2234                 error = copyin(uap->abs_timeout, &ets, sizeof(ets));
 2235                 if (error != 0)
 2236                         return (error);
 2237                 abs_timeout = &ets;
 2238         } else
 2239                 abs_timeout = NULL;
 2240         waitok = !(fp->f_flag & O_NONBLOCK);
 2241         error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
 2242                 uap->msg_prio, waitok, abs_timeout);
 2243         fdrop(fp, td);
 2244         return (error);
 2245 }
 2246 
 2247 static int
 2248 kern_kmq_notify(struct thread *td, int mqd, struct sigevent *sigev)
 2249 {
 2250 #ifdef CAPABILITIES
 2251         cap_rights_t rights;
 2252 #endif
 2253         struct filedesc *fdp;
 2254         struct proc *p;
 2255         struct mqueue *mq;
 2256         struct file *fp, *fp2;
 2257         struct mqueue_notifier *nt, *newnt = NULL;
 2258         int error;
 2259 
 2260         if (sigev != NULL) {
 2261                 if (sigev->sigev_notify != SIGEV_SIGNAL &&
 2262                     sigev->sigev_notify != SIGEV_THREAD_ID &&
 2263                     sigev->sigev_notify != SIGEV_NONE)
 2264                         return (EINVAL);
 2265                 if ((sigev->sigev_notify == SIGEV_SIGNAL ||
 2266                     sigev->sigev_notify == SIGEV_THREAD_ID) &&
 2267                     !_SIG_VALID(sigev->sigev_signo))
 2268                         return (EINVAL);
 2269         }
 2270         p = td->td_proc;
 2271         fdp = td->td_proc->p_fd;
 2272         error = getmq(td, mqd, &fp, NULL, &mq);
 2273         if (error)
 2274                 return (error);
 2275 again:
 2276         FILEDESC_SLOCK(fdp);
 2277         fp2 = fget_locked(fdp, mqd);
 2278         if (fp2 == NULL) {
 2279                 FILEDESC_SUNLOCK(fdp);
 2280                 error = EBADF;
 2281                 goto out;
 2282         }
 2283 #ifdef CAPABILITIES
 2284         error = cap_check(cap_rights(fdp, mqd),
 2285             cap_rights_init(&rights, CAP_EVENT));
 2286         if (error) {
 2287                 FILEDESC_SUNLOCK(fdp);
 2288                 goto out;
 2289         }
 2290 #endif
 2291         if (fp2 != fp) {
 2292                 FILEDESC_SUNLOCK(fdp);
 2293                 error = EBADF;
 2294                 goto out;
 2295         }
 2296         mtx_lock(&mq->mq_mutex);
 2297         FILEDESC_SUNLOCK(fdp);
 2298         if (sigev != NULL) {
 2299                 if (mq->mq_notifier != NULL) {
 2300                         error = EBUSY;
 2301                 } else {
 2302                         PROC_LOCK(p);
 2303                         nt = notifier_search(p, mqd);
 2304                         if (nt == NULL) {
 2305                                 if (newnt == NULL) {
 2306                                         PROC_UNLOCK(p);
 2307                                         mtx_unlock(&mq->mq_mutex);
 2308                                         newnt = notifier_alloc();
 2309                                         goto again;
 2310                                 }
 2311                         }
 2312 
 2313                         if (nt != NULL) {
 2314                                 sigqueue_take(&nt->nt_ksi);
 2315                                 if (newnt != NULL) {
 2316                                         notifier_free(newnt);
 2317                                         newnt = NULL;
 2318                                 }
 2319                         } else {
 2320                                 nt = newnt;
 2321                                 newnt = NULL;
 2322                                 ksiginfo_init(&nt->nt_ksi);
 2323                                 nt->nt_ksi.ksi_flags |= KSI_INS | KSI_EXT;
 2324                                 nt->nt_ksi.ksi_code = SI_MESGQ;
 2325                                 nt->nt_proc = p;
 2326                                 nt->nt_ksi.ksi_mqd = mqd;
 2327                                 notifier_insert(p, nt);
 2328                         }
 2329                         nt->nt_sigev = *sigev;
 2330                         mq->mq_notifier = nt;
 2331                         PROC_UNLOCK(p);
 2332                         /*
 2333                          * if there is no receivers and message queue
 2334                          * is not empty, we should send notification
 2335                          * as soon as possible.
 2336                          */
 2337                         if (mq->mq_receivers == 0 &&
 2338                             !TAILQ_EMPTY(&mq->mq_msgq))
 2339                                 mqueue_send_notification(mq);
 2340                 }
 2341         } else {
 2342                 notifier_remove(p, mq, mqd);
 2343         }
 2344         mtx_unlock(&mq->mq_mutex);
 2345 
 2346 out:
 2347         fdrop(fp, td);
 2348         if (newnt != NULL)
 2349                 notifier_free(newnt);
 2350         return (error);
 2351 }
 2352 
 2353 int
 2354 sys_kmq_notify(struct thread *td, struct kmq_notify_args *uap)
 2355 {
 2356         struct sigevent ev, *evp;
 2357         int error;
 2358 
 2359         if (uap->sigev == NULL) {
 2360                 evp = NULL;
 2361         } else {
 2362                 error = copyin(uap->sigev, &ev, sizeof(ev));
 2363                 if (error != 0)
 2364                         return (error);
 2365                 evp = &ev;
 2366         }
 2367         return (kern_kmq_notify(td, uap->mqd, evp));
 2368 }
 2369 
 2370 static void
 2371 mqueue_fdclose(struct thread *td, int fd, struct file *fp)
 2372 {
 2373         struct filedesc *fdp;
 2374         struct mqueue *mq;
 2375  
 2376         fdp = td->td_proc->p_fd;
 2377         FILEDESC_LOCK_ASSERT(fdp);
 2378 
 2379         if (fp->f_ops == &mqueueops) {
 2380                 mq = FPTOMQ(fp);
 2381                 mtx_lock(&mq->mq_mutex);
 2382                 notifier_remove(td->td_proc, mq, fd);
 2383 
 2384                 /* have to wakeup thread in same process */
 2385                 if (mq->mq_flags & MQ_RSEL) {
 2386                         mq->mq_flags &= ~MQ_RSEL;
 2387                         selwakeup(&mq->mq_rsel);
 2388                 }
 2389                 if (mq->mq_flags & MQ_WSEL) {
 2390                         mq->mq_flags &= ~MQ_WSEL;
 2391                         selwakeup(&mq->mq_wsel);
 2392                 }
 2393                 mtx_unlock(&mq->mq_mutex);
 2394         }
 2395 }
 2396 
 2397 static void
 2398 mq_proc_exit(void *arg __unused, struct proc *p)
 2399 {
 2400         struct filedesc *fdp;
 2401         struct file *fp;
 2402         struct mqueue *mq;
 2403         int i;
 2404 
 2405         fdp = p->p_fd;
 2406         FILEDESC_SLOCK(fdp);
 2407         for (i = 0; i < fdp->fd_nfiles; ++i) {
 2408                 fp = fget_locked(fdp, i);
 2409                 if (fp != NULL && fp->f_ops == &mqueueops) {
 2410                         mq = FPTOMQ(fp);
 2411                         mtx_lock(&mq->mq_mutex);
 2412                         notifier_remove(p, FPTOMQ(fp), i);
 2413                         mtx_unlock(&mq->mq_mutex);
 2414                 }
 2415         }
 2416         FILEDESC_SUNLOCK(fdp);
 2417         KASSERT(LIST_EMPTY(&p->p_mqnotifier), ("mq notifiers left"));
 2418 }
 2419 
 2420 static int
 2421 mqf_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
 2422         int flags, struct thread *td)
 2423 {
 2424         return (EOPNOTSUPP);
 2425 }
 2426 
 2427 static int
 2428 mqf_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
 2429         int flags, struct thread *td)
 2430 {
 2431         return (EOPNOTSUPP);
 2432 }
 2433 
 2434 static int
 2435 mqf_truncate(struct file *fp, off_t length, struct ucred *active_cred,
 2436     struct thread *td)
 2437 {
 2438 
 2439         return (EINVAL);
 2440 }
 2441 
 2442 static int
 2443 mqf_ioctl(struct file *fp, u_long cmd, void *data,
 2444         struct ucred *active_cred, struct thread *td)
 2445 {
 2446         return (ENOTTY);
 2447 }
 2448 
 2449 static int
 2450 mqf_poll(struct file *fp, int events, struct ucred *active_cred,
 2451         struct thread *td)
 2452 {
 2453         struct mqueue *mq = FPTOMQ(fp);
 2454         int revents = 0;
 2455 
 2456         mtx_lock(&mq->mq_mutex);
 2457         if (events & (POLLIN | POLLRDNORM)) {
 2458                 if (mq->mq_curmsgs) {
 2459                         revents |= events & (POLLIN | POLLRDNORM);
 2460                 } else {
 2461                         mq->mq_flags |= MQ_RSEL;
 2462                         selrecord(td, &mq->mq_rsel);
 2463                 }
 2464         }
 2465         if (events & POLLOUT) {
 2466                 if (mq->mq_curmsgs < mq->mq_maxmsg)
 2467                         revents |= POLLOUT;
 2468                 else {
 2469                         mq->mq_flags |= MQ_WSEL;
 2470                         selrecord(td, &mq->mq_wsel);
 2471                 }
 2472         }
 2473         mtx_unlock(&mq->mq_mutex);
 2474         return (revents);
 2475 }
 2476 
 2477 static int
 2478 mqf_close(struct file *fp, struct thread *td)
 2479 {
 2480         struct mqfs_node *pn;
 2481 
 2482         fp->f_ops = &badfileops;
 2483         pn = fp->f_data;
 2484         fp->f_data = NULL;
 2485         sx_xlock(&mqfs_data.mi_lock);
 2486         mqnode_release(pn);
 2487         sx_xunlock(&mqfs_data.mi_lock);
 2488         return (0);
 2489 }
 2490 
 2491 static int
 2492 mqf_stat(struct file *fp, struct stat *st, struct ucred *active_cred,
 2493         struct thread *td)
 2494 {
 2495         struct mqfs_node *pn = fp->f_data;
 2496 
 2497         bzero(st, sizeof *st);
 2498         sx_xlock(&mqfs_data.mi_lock);
 2499         st->st_atim = pn->mn_atime;
 2500         st->st_mtim = pn->mn_mtime;
 2501         st->st_ctim = pn->mn_ctime;
 2502         st->st_birthtim = pn->mn_birth;
 2503         st->st_uid = pn->mn_uid;
 2504         st->st_gid = pn->mn_gid;
 2505         st->st_mode = S_IFIFO | pn->mn_mode;
 2506         sx_xunlock(&mqfs_data.mi_lock);
 2507         return (0);
 2508 }
 2509 
 2510 static int
 2511 mqf_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
 2512     struct thread *td)
 2513 {
 2514         struct mqfs_node *pn;
 2515         int error;
 2516 
 2517         error = 0;
 2518         pn = fp->f_data;
 2519         sx_xlock(&mqfs_data.mi_lock);
 2520         error = vaccess(VREG, pn->mn_mode, pn->mn_uid, pn->mn_gid, VADMIN,
 2521             active_cred, NULL);
 2522         if (error != 0)
 2523                 goto out;
 2524         pn->mn_mode = mode & ACCESSPERMS;
 2525 out:
 2526         sx_xunlock(&mqfs_data.mi_lock);
 2527         return (error);
 2528 }
 2529 
 2530 static int
 2531 mqf_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
 2532     struct thread *td)
 2533 {
 2534         struct mqfs_node *pn;
 2535         int error;
 2536 
 2537         error = 0;
 2538         pn = fp->f_data;
 2539         sx_xlock(&mqfs_data.mi_lock);
 2540         if (uid == (uid_t)-1)
 2541                 uid = pn->mn_uid;
 2542         if (gid == (gid_t)-1)
 2543                 gid = pn->mn_gid;
 2544         if (((uid != pn->mn_uid && uid != active_cred->cr_uid) ||
 2545             (gid != pn->mn_gid && !groupmember(gid, active_cred))) &&
 2546             (error = priv_check_cred(active_cred, PRIV_VFS_CHOWN, 0)))
 2547                 goto out;
 2548         pn->mn_uid = uid;
 2549         pn->mn_gid = gid;
 2550 out:
 2551         sx_xunlock(&mqfs_data.mi_lock);
 2552         return (error);
 2553 }
 2554 
 2555 static int
 2556 mqf_kqfilter(struct file *fp, struct knote *kn)
 2557 {
 2558         struct mqueue *mq = FPTOMQ(fp);
 2559         int error = 0;
 2560 
 2561         if (kn->kn_filter == EVFILT_READ) {
 2562                 kn->kn_fop = &mq_rfiltops;
 2563                 knlist_add(&mq->mq_rsel.si_note, kn, 0);
 2564         } else if (kn->kn_filter == EVFILT_WRITE) {
 2565                 kn->kn_fop = &mq_wfiltops;
 2566                 knlist_add(&mq->mq_wsel.si_note, kn, 0);
 2567         } else
 2568                 error = EINVAL;
 2569         return (error);
 2570 }
 2571 
 2572 static void
 2573 filt_mqdetach(struct knote *kn)
 2574 {
 2575         struct mqueue *mq = FPTOMQ(kn->kn_fp);
 2576 
 2577         if (kn->kn_filter == EVFILT_READ)
 2578                 knlist_remove(&mq->mq_rsel.si_note, kn, 0);
 2579         else if (kn->kn_filter == EVFILT_WRITE)
 2580                 knlist_remove(&mq->mq_wsel.si_note, kn, 0);
 2581         else
 2582                 panic("filt_mqdetach");
 2583 }
 2584 
 2585 static int
 2586 filt_mqread(struct knote *kn, long hint)
 2587 {
 2588         struct mqueue *mq = FPTOMQ(kn->kn_fp);
 2589 
 2590         mtx_assert(&mq->mq_mutex, MA_OWNED);
 2591         return (mq->mq_curmsgs != 0);
 2592 }
 2593 
 2594 static int
 2595 filt_mqwrite(struct knote *kn, long hint)
 2596 {
 2597         struct mqueue *mq = FPTOMQ(kn->kn_fp);
 2598 
 2599         mtx_assert(&mq->mq_mutex, MA_OWNED);
 2600         return (mq->mq_curmsgs < mq->mq_maxmsg);
 2601 }
 2602 
 2603 static struct fileops mqueueops = {
 2604         .fo_read                = mqf_read,
 2605         .fo_write               = mqf_write,
 2606         .fo_truncate            = mqf_truncate,
 2607         .fo_ioctl               = mqf_ioctl,
 2608         .fo_poll                = mqf_poll,
 2609         .fo_kqfilter            = mqf_kqfilter,
 2610         .fo_stat                = mqf_stat,
 2611         .fo_chmod               = mqf_chmod,
 2612         .fo_chown               = mqf_chown,
 2613         .fo_close               = mqf_close,
 2614         .fo_sendfile            = invfo_sendfile,
 2615 };
 2616 
 2617 static struct vop_vector mqfs_vnodeops = {
 2618         .vop_default            = &default_vnodeops,
 2619         .vop_access             = mqfs_access,
 2620         .vop_cachedlookup       = mqfs_lookup,
 2621         .vop_lookup             = vfs_cache_lookup,
 2622         .vop_reclaim            = mqfs_reclaim,
 2623         .vop_create             = mqfs_create,
 2624         .vop_remove             = mqfs_remove,
 2625         .vop_inactive           = mqfs_inactive,
 2626         .vop_open               = mqfs_open,
 2627         .vop_close              = mqfs_close,
 2628         .vop_getattr            = mqfs_getattr,
 2629         .vop_setattr            = mqfs_setattr,
 2630         .vop_read               = mqfs_read,
 2631         .vop_write              = VOP_EOPNOTSUPP,
 2632         .vop_readdir            = mqfs_readdir,
 2633         .vop_mkdir              = VOP_EOPNOTSUPP,
 2634         .vop_rmdir              = VOP_EOPNOTSUPP
 2635 };
 2636 
 2637 static struct vfsops mqfs_vfsops = {
 2638         .vfs_init               = mqfs_init,
 2639         .vfs_uninit             = mqfs_uninit,
 2640         .vfs_mount              = mqfs_mount,
 2641         .vfs_unmount            = mqfs_unmount,
 2642         .vfs_root               = mqfs_root,
 2643         .vfs_statfs             = mqfs_statfs,
 2644 };
 2645 
 2646 static struct vfsconf mqueuefs_vfsconf = {
 2647         .vfc_version = VFS_VERSION,
 2648         .vfc_name = "mqueuefs",
 2649         .vfc_vfsops = &mqfs_vfsops,
 2650         .vfc_typenum = -1,
 2651         .vfc_flags = VFCF_SYNTHETIC
 2652 };
 2653 
 2654 static struct syscall_helper_data mq_syscalls[] = {
 2655         SYSCALL_INIT_HELPER(kmq_open),
 2656         SYSCALL_INIT_HELPER(kmq_setattr),
 2657         SYSCALL_INIT_HELPER(kmq_timedsend),
 2658         SYSCALL_INIT_HELPER(kmq_timedreceive),
 2659         SYSCALL_INIT_HELPER(kmq_notify),
 2660         SYSCALL_INIT_HELPER(kmq_unlink),
 2661         SYSCALL_INIT_LAST
 2662 };
 2663 
 2664 #ifdef COMPAT_FREEBSD32
 2665 #include <compat/freebsd32/freebsd32.h>
 2666 #include <compat/freebsd32/freebsd32_proto.h>
 2667 #include <compat/freebsd32/freebsd32_signal.h>
 2668 #include <compat/freebsd32/freebsd32_syscall.h>
 2669 #include <compat/freebsd32/freebsd32_util.h>
 2670 
 2671 static void
 2672 mq_attr_from32(const struct mq_attr32 *from, struct mq_attr *to)
 2673 {
 2674 
 2675         to->mq_flags = from->mq_flags;
 2676         to->mq_maxmsg = from->mq_maxmsg;
 2677         to->mq_msgsize = from->mq_msgsize;
 2678         to->mq_curmsgs = from->mq_curmsgs;
 2679 }
 2680 
 2681 static void
 2682 mq_attr_to32(const struct mq_attr *from, struct mq_attr32 *to)
 2683 {
 2684 
 2685         to->mq_flags = from->mq_flags;
 2686         to->mq_maxmsg = from->mq_maxmsg;
 2687         to->mq_msgsize = from->mq_msgsize;
 2688         to->mq_curmsgs = from->mq_curmsgs;
 2689 }
 2690 
 2691 int
 2692 freebsd32_kmq_open(struct thread *td, struct freebsd32_kmq_open_args *uap)
 2693 {
 2694         struct mq_attr attr;
 2695         struct mq_attr32 attr32;
 2696         int flags, error;
 2697 
 2698         if ((uap->flags & O_ACCMODE) == O_ACCMODE || uap->flags & O_EXEC)
 2699                 return (EINVAL);
 2700         flags = FFLAGS(uap->flags);
 2701         if ((flags & O_CREAT) != 0 && uap->attr != NULL) {
 2702                 error = copyin(uap->attr, &attr32, sizeof(attr32));
 2703                 if (error)
 2704                         return (error);
 2705                 mq_attr_from32(&attr32, &attr);
 2706         }
 2707         return (kern_kmq_open(td, uap->path, flags, uap->mode,
 2708             uap->attr != NULL ? &attr : NULL));
 2709 }
 2710 
 2711 int
 2712 freebsd32_kmq_setattr(struct thread *td, struct freebsd32_kmq_setattr_args *uap)
 2713 {
 2714         struct mq_attr attr, oattr;
 2715         struct mq_attr32 attr32, oattr32;
 2716         int error;
 2717 
 2718         if (uap->attr != NULL) {
 2719                 error = copyin(uap->attr, &attr32, sizeof(attr32));
 2720                 if (error != 0)
 2721                         return (error);
 2722                 mq_attr_from32(&attr32, &attr);
 2723         }
 2724         error = kern_kmq_setattr(td, uap->mqd, uap->attr != NULL ? &attr : NULL,
 2725             &oattr);
 2726         if (error != 0)
 2727                 return (error);
 2728         if (uap->oattr != NULL) {
 2729                 mq_attr_to32(&oattr, &oattr32);
 2730                 error = copyout(&oattr32, uap->oattr, sizeof(oattr32));
 2731         }
 2732         return (error);
 2733 }
 2734 
 2735 int
 2736 freebsd32_kmq_timedsend(struct thread *td,
 2737     struct freebsd32_kmq_timedsend_args *uap)
 2738 {
 2739         struct mqueue *mq;
 2740         struct file *fp;
 2741         struct timespec32 ets32;
 2742         struct timespec *abs_timeout, ets;
 2743         int error;
 2744         int waitok;
 2745 
 2746         error = getmq_write(td, uap->mqd, &fp, NULL, &mq);
 2747         if (error)
 2748                 return (error);
 2749         if (uap->abs_timeout != NULL) {
 2750                 error = copyin(uap->abs_timeout, &ets32, sizeof(ets32));
 2751                 if (error != 0)
 2752                         return (error);
 2753                 CP(ets32, ets, tv_sec);
 2754                 CP(ets32, ets, tv_nsec);
 2755                 abs_timeout = &ets;
 2756         } else
 2757                 abs_timeout = NULL;
 2758         waitok = !(fp->f_flag & O_NONBLOCK);
 2759         error = mqueue_send(mq, uap->msg_ptr, uap->msg_len,
 2760                 uap->msg_prio, waitok, abs_timeout);
 2761         fdrop(fp, td);
 2762         return (error);
 2763 }
 2764 
 2765 int
 2766 freebsd32_kmq_timedreceive(struct thread *td,
 2767     struct freebsd32_kmq_timedreceive_args *uap)
 2768 {
 2769         struct mqueue *mq;
 2770         struct file *fp;
 2771         struct timespec32 ets32;
 2772         struct timespec *abs_timeout, ets;
 2773         int error, waitok;
 2774 
 2775         error = getmq_read(td, uap->mqd, &fp, NULL, &mq);
 2776         if (error)
 2777                 return (error);
 2778         if (uap->abs_timeout != NULL) {
 2779                 error = copyin(uap->abs_timeout, &ets32, sizeof(ets32));
 2780                 if (error != 0)
 2781                         return (error);
 2782                 CP(ets32, ets, tv_sec);
 2783                 CP(ets32, ets, tv_nsec);
 2784                 abs_timeout = &ets;
 2785         } else
 2786                 abs_timeout = NULL;
 2787         waitok = !(fp->f_flag & O_NONBLOCK);
 2788         error = mqueue_receive(mq, uap->msg_ptr, uap->msg_len,
 2789                 uap->msg_prio, waitok, abs_timeout);
 2790         fdrop(fp, td);
 2791         return (error);
 2792 }
 2793 
 2794 int
 2795 freebsd32_kmq_notify(struct thread *td, struct freebsd32_kmq_notify_args *uap)
 2796 {
 2797         struct sigevent ev, *evp;
 2798         struct sigevent32 ev32;
 2799         int error;
 2800 
 2801         if (uap->sigev == NULL) {
 2802                 evp = NULL;
 2803         } else {
 2804                 error = copyin(uap->sigev, &ev32, sizeof(ev32));
 2805                 if (error != 0)
 2806                         return (error);
 2807                 error = convert_sigevent32(&ev32, &ev);
 2808                 if (error != 0)
 2809                         return (error);
 2810                 evp = &ev;
 2811         }
 2812         return (kern_kmq_notify(td, uap->mqd, evp));
 2813 }
 2814 
 2815 static struct syscall_helper_data mq32_syscalls[] = {
 2816         SYSCALL32_INIT_HELPER(freebsd32_kmq_open),
 2817         SYSCALL32_INIT_HELPER(freebsd32_kmq_setattr),
 2818         SYSCALL32_INIT_HELPER(freebsd32_kmq_timedsend),
 2819         SYSCALL32_INIT_HELPER(freebsd32_kmq_timedreceive),
 2820         SYSCALL32_INIT_HELPER(freebsd32_kmq_notify),
 2821         SYSCALL32_INIT_HELPER_COMPAT(kmq_unlink),
 2822         SYSCALL_INIT_LAST
 2823 };
 2824 #endif
 2825 
 2826 static int
 2827 mqinit(void)
 2828 {
 2829         int error;
 2830 
 2831         error = syscall_helper_register(mq_syscalls);
 2832         if (error != 0)
 2833                 return (error);
 2834 #ifdef COMPAT_FREEBSD32
 2835         error = syscall32_helper_register(mq32_syscalls);
 2836         if (error != 0)
 2837                 return (error);
 2838 #endif
 2839         return (0);
 2840 }
 2841 
 2842 static int
 2843 mqunload(void)
 2844 {
 2845 
 2846 #ifdef COMPAT_FREEBSD32
 2847         syscall32_helper_unregister(mq32_syscalls);
 2848 #endif
 2849         syscall_helper_unregister(mq_syscalls);
 2850         return (0);
 2851 }
 2852 
 2853 static int
 2854 mq_modload(struct module *module, int cmd, void *arg)
 2855 {
 2856         int error = 0;
 2857 
 2858         error = vfs_modevent(module, cmd, arg);
 2859         if (error != 0)
 2860                 return (error);
 2861 
 2862         switch (cmd) {
 2863         case MOD_LOAD:
 2864                 error = mqinit();
 2865                 if (error != 0)
 2866                         mqunload();
 2867                 break;
 2868         case MOD_UNLOAD:
 2869                 error = mqunload();
 2870                 break;
 2871         default:
 2872                 break;
 2873         }
 2874         return (error);
 2875 }
 2876 
 2877 static moduledata_t mqueuefs_mod = {
 2878         "mqueuefs",
 2879         mq_modload,
 2880         &mqueuefs_vfsconf
 2881 };
 2882 DECLARE_MODULE(mqueuefs, mqueuefs_mod, SI_SUB_VFS, SI_ORDER_MIDDLE);
 2883 MODULE_VERSION(mqueuefs, 1);

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