sys/kern/sys_socket.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1990, 1993
   3  *      The Regents of the University of California.  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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)sys_socket.c        8.1 (Berkeley) 6/10/93
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "opt_mac.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/file.h>
  40 #include <sys/filedesc.h>
  41 #include <sys/proc.h>
  42 #include <sys/protosw.h>
  43 #include <sys/sigio.h>
  44 #include <sys/signal.h>
  45 #include <sys/signalvar.h>
  46 #include <sys/socket.h>
  47 #include <sys/socketvar.h>
  48 #include <sys/filio.h>                  /* XXX */
  49 #include <sys/sockio.h>
  50 #include <sys/stat.h>
  51 #include <sys/uio.h>
  52 #include <sys/ucred.h>
  53
  54 #include <net/if.h>
  55 #include <net/route.h>
  56
  57 #include <security/mac/mac_framework.h>
  58
  59 struct fileops  socketops = {
  60         .fo_read = soo_read,
  61         .fo_write = soo_write,
  62         .fo_truncate = soo_truncate,
  63         .fo_ioctl = soo_ioctl,
  64         .fo_poll = soo_poll,
  65         .fo_kqfilter = soo_kqfilter,
  66         .fo_stat = soo_stat,
  67         .fo_close = soo_close,
  68         .fo_flags = DFLAG_PASSABLE
  69 };
  70
  71 /* ARGSUSED */
  72 int
  73 soo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
  74     int flags, struct thread *td)
  75 {
  76         struct socket *so = fp->f_data;
  77 #ifdef MAC
  78         int error;
  79
  80         SOCK_LOCK(so);
  81         error = mac_socket_check_receive(active_cred, so);
  82         SOCK_UNLOCK(so);
  83         if (error)
  84                 return (error);
  85 #endif
  86         return (soreceive(so, 0, uio, 0, 0, 0));
  87 }
  88
  89 /* ARGSUSED */
  90 int
  91 soo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
  92     int flags, struct thread *td)
  93 {
  94         struct socket *so = fp->f_data;
  95         int error;
  96
  97 #ifdef MAC
  98         SOCK_LOCK(so);
  99         error = mac_socket_check_send(active_cred, so);
 100         SOCK_UNLOCK(so);
 101         if (error)
 102                 return (error);
 103 #endif
 104         error = sosend(so, 0, uio, 0, 0, 0, uio->uio_td);
 105         if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0) {
 106                 PROC_LOCK(uio->uio_td->td_proc);
 107                 psignal(uio->uio_td->td_proc, SIGPIPE);
 108                 PROC_UNLOCK(uio->uio_td->td_proc);
 109         }
 110         return (error);
 111 }
 112
 113 int
 114 soo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
 115     struct thread *td)
 116 {
 117
 118         return (EINVAL);
 119 }
 120
 121 int
 122 soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
 123     struct thread *td)
 124 {
 125         struct socket *so = fp->f_data;
 126         int error = 0;
 127
 128         switch (cmd) {
 129         case FIONBIO:
 130                 SOCK_LOCK(so);
 131                 if (*(int *)data)
 132                         so->so_state |= SS_NBIO;
 133                 else
 134                         so->so_state &= ~SS_NBIO;
 135                 SOCK_UNLOCK(so);
 136                 break;
 137
 138         case FIOASYNC:
 139                 /*
 140                  * XXXRW: This code separately acquires SOCK_LOCK(so) and
 141                  * SOCKBUF_LOCK(&so->so_rcv) even though they are the same
 142                  * mutex to avoid introducing the assumption that they are
 143                  * the same.
 144                  */
 145                 if (*(int *)data) {
 146                         SOCK_LOCK(so);
 147                         so->so_state |= SS_ASYNC;
 148                         SOCK_UNLOCK(so);
 149                         SOCKBUF_LOCK(&so->so_rcv);
 150                         so->so_rcv.sb_flags |= SB_ASYNC;
 151                         SOCKBUF_UNLOCK(&so->so_rcv);
 152                         SOCKBUF_LOCK(&so->so_snd);
 153                         so->so_snd.sb_flags |= SB_ASYNC;
 154                         SOCKBUF_UNLOCK(&so->so_snd);
 155                 } else {
 156                         SOCK_LOCK(so);
 157                         so->so_state &= ~SS_ASYNC;
 158                         SOCK_UNLOCK(so);
 159                         SOCKBUF_LOCK(&so->so_rcv);
 160                         so->so_rcv.sb_flags &= ~SB_ASYNC;
 161                         SOCKBUF_UNLOCK(&so->so_rcv);
 162                         SOCKBUF_LOCK(&so->so_snd);
 163                         so->so_snd.sb_flags &= ~SB_ASYNC;
 164                         SOCKBUF_UNLOCK(&so->so_snd);
 165                 }
 166                 break;
 167
 168         case FIONREAD:
 169                 /* Unlocked read. */
 170                 *(int *)data = so->so_rcv.sb_cc;
 171                 break;
 172
 173         case FIOSETOWN:
 174                 error = fsetown(*(int *)data, &so->so_sigio);
 175                 break;
 176
 177         case FIOGETOWN:
 178                 *(int *)data = fgetown(&so->so_sigio);
 179                 break;
 180
 181         case SIOCSPGRP:
 182                 error = fsetown(-(*(int *)data), &so->so_sigio);
 183                 break;
 184
 185         case SIOCGPGRP:
 186                 *(int *)data = -fgetown(&so->so_sigio);
 187                 break;
 188
 189         case SIOCATMARK:
 190                 /* Unlocked read. */
 191                 *(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
 192                 break;
 193         default:
 194                 /*
 195                  * Interface/routing/protocol specific ioctls: interface and
 196                  * routing ioctls should have a different entry since a
 197                  * socket is unnecessary.
 198                  */
 199                 if (IOCGROUP(cmd) == 'i')
 200                         error = ifioctl(so, cmd, data, td);
 201                 else if (IOCGROUP(cmd) == 'r')
 202                         error = rtioctl_fib(cmd, data, so->so_fibnum);
 203                 else
 204                         error = ((*so->so_proto->pr_usrreqs->pru_control)
 205                             (so, cmd, data, 0, td));
 206                 break;
 207         }
 208         return (error);
 209 }
 210
 211 int
 212 soo_poll(struct file *fp, int events, struct ucred *active_cred,
 213     struct thread *td)
 214 {
 215         struct socket *so = fp->f_data;
 216 #ifdef MAC
 217         int error;
 218
 219         SOCK_LOCK(so);
 220         error = mac_socket_check_poll(active_cred, so);
 221         SOCK_UNLOCK(so);
 222         if (error)
 223                 return (error);
 224 #endif
 225         return (sopoll(so, events, fp->f_cred, td));
 226 }
 227
 228 int
 229 soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
 230     struct thread *td)
 231 {
 232         struct socket *so = fp->f_data;
 233 #ifdef MAC
 234         int error;
 235 #endif
 236
 237         bzero((caddr_t)ub, sizeof (*ub));
 238         ub->st_mode = S_IFSOCK;
 239 #ifdef MAC
 240         SOCK_LOCK(so);
 241         error = mac_socket_check_stat(active_cred, so);
 242         SOCK_UNLOCK(so);
 243         if (error)
 244                 return (error);
 245 #endif
 246         /*
 247          * If SBS_CANTRCVMORE is set, but there's still data left in the
 248          * receive buffer, the socket is still readable.
 249          *
 250          * XXXRW: perhaps should lock socket buffer so st_size result is
 251          * consistent.
 252          */
 253         /* Unlocked read. */
 254         if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
 255             so->so_rcv.sb_cc != 0)
 256                 ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
 257         if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
 258                 ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
 259         ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
 260         ub->st_uid = so->so_cred->cr_uid;
 261         ub->st_gid = so->so_cred->cr_gid;
 262         return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);
 263 }
 264
 265 /*
 266  * API socket close on file pointer.  We call soclose() to close the socket
 267  * (including initiating closing protocols).  soclose() will sorele() the
 268  * file reference but the actual socket will not go away until the socket's
 269  * ref count hits 0.
 270  */
 271 /* ARGSUSED */
 272 int
 273 soo_close(struct file *fp, struct thread *td)
 274 {
 275         int error = 0;
 276         struct socket *so;
 277
 278         so = fp->f_data;
 279         fp->f_ops = &badfileops;
 280         fp->f_data = NULL;
 281
 282         if (so)
 283                 error = soclose(so);
 284         return (error);
 285 }