external/bsd/tmux/dist/compat/imsg.c

   1 /* Id */
   2 /*      $OpenBSD: imsg.c,v 1.3 2010/05/26 13:56:07 nicm Exp $   */
   3
   4 /*
   5  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #include <sys/param.h>
  21 #include <sys/socket.h>
  22 #include <sys/uio.h>
  23
  24 #include <errno.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <strings.h>
  28 #include <unistd.h>
  29
  30 #include "tmux.h"
  31
  32 int      imsg_get_fd(struct imsgbuf *);
  33
  34 void
  35 imsg_init(struct imsgbuf *ibuf, int fd)
  36 {
  37         msgbuf_init(&ibuf->w);
  38         bzero(&ibuf->r, sizeof(ibuf->r));
  39         ibuf->fd = fd;
  40         ibuf->w.fd = fd;
  41         ibuf->pid = getpid();
  42         TAILQ_INIT(&ibuf->fds);
  43 }
  44
  45 ssize_t
  46 imsg_read(struct imsgbuf *ibuf)
  47 {
  48         struct msghdr            msg;
  49         struct cmsghdr          *cmsg;
  50         union {
  51                 struct cmsghdr hdr;
  52                 char    buf[CMSG_SPACE(sizeof(int) * 16)];
  53         } cmsgbuf;
  54         struct iovec             iov;
  55         ssize_t                  n;
  56         int                      fd;
  57         struct imsg_fd          *ifd;
  58
  59         bzero(&msg, sizeof(msg));
  60
  61         iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
  62         iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
  63         msg.msg_iov = &iov;
  64         msg.msg_iovlen = 1;
  65         msg.msg_control = &cmsgbuf.buf;
  66         msg.msg_controllen = CMSG_SPACE(sizeof(int) * 16);
  67
  68         if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
  69                 if (errno != EINTR && errno != EAGAIN) {
  70                         return (-1);
  71                 }
  72                 return (-2);
  73         }
  74
  75         ibuf->r.wpos += n;
  76
  77         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
  78             cmsg = CMSG_NXTHDR(&msg, cmsg)) {
  79                 if (cmsg->cmsg_level == SOL_SOCKET &&
  80                     cmsg->cmsg_type == SCM_RIGHTS) {
  81                         fd = (*(int *)CMSG_DATA(cmsg));
  82                         if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL) {
  83                                 close(fd);
  84                                 return (-1);
  85                         }
  86                         ifd->fd = fd;
  87                         TAILQ_INSERT_TAIL(&ibuf->fds, ifd, entry);
  88                 }
  89                 /* we do not handle other ctl data level */
  90         }
  91
  92         return (n);
  93 }
  94
  95 ssize_t
  96 imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
  97 {
  98         size_t                   av, left, datalen;
  99
 100         av = ibuf->r.wpos;
 101
 102         if (IMSG_HEADER_SIZE > av)
 103                 return (0);
 104
 105         memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
 106         if (imsg->hdr.len < IMSG_HEADER_SIZE ||
 107             imsg->hdr.len > MAX_IMSGSIZE) {
 108                 errno = ERANGE;
 109                 return (-1);
 110         }
 111         if (imsg->hdr.len > av)
 112                 return (0);
 113         datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
 114         ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
 115         if ((imsg->data = malloc(datalen)) == NULL && datalen != 0)
 116                 return (-1);
 117
 118         if (imsg->hdr.flags & IMSGF_HASFD)
 119                 imsg->fd = imsg_get_fd(ibuf);
 120         else
 121                 imsg->fd = -1;
 122
 123         memcpy(imsg->data, ibuf->r.rptr, datalen);
 124
 125         if (imsg->hdr.len < av) {
 126                 left = av - imsg->hdr.len;
 127                 memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
 128                 ibuf->r.wpos = left;
 129         } else
 130                 ibuf->r.wpos = 0;
 131
 132         return (datalen + IMSG_HEADER_SIZE);
 133 }
 134
 135 int
 136 imsg_compose(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
 137     pid_t pid, int fd, void *data, u_int16_t datalen)
 138 {
 139         struct ibuf     *wbuf;
 140
 141         if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
 142                 return (-1);
 143
 144         if (imsg_add(wbuf, data, datalen) == -1)
 145                 return (-1);
 146
 147         wbuf->fd = fd;
 148
 149         imsg_close(ibuf, wbuf);
 150
 151         return (1);
 152 }
 153
 154 int
 155 imsg_composev(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
 156     pid_t pid, int fd, const struct iovec *iov, int iovcnt)
 157 {
 158         struct ibuf     *wbuf;
 159         int              i, datalen = 0;
 160
 161         for (i = 0; i < iovcnt; i++)
 162                 datalen += iov[i].iov_len;
 163
 164         if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
 165                 return (-1);
 166
 167         for (i = 0; i < iovcnt; i++)
 168                 if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
 169                         return (-1);
 170
 171         wbuf->fd = fd;
 172
 173         imsg_close(ibuf, wbuf);
 174
 175         return (1);
 176 }
 177
 178 /* ARGSUSED */
 179 struct ibuf *
 180 imsg_create(struct imsgbuf *ibuf, u_int32_t type, u_int32_t peerid,
 181     pid_t pid, u_int16_t datalen)
 182 {
 183         struct ibuf     *wbuf;
 184         struct imsg_hdr  hdr;
 185
 186         datalen += IMSG_HEADER_SIZE;
 187         if (datalen > MAX_IMSGSIZE) {
 188                 errno = ERANGE;
 189                 return (NULL);
 190         }
 191
 192         hdr.type = type;
 193         hdr.flags = 0;
 194         hdr.peerid = peerid;
 195         if ((hdr.pid = pid) == 0)
 196                 hdr.pid = ibuf->pid;
 197         if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
 198                 return (NULL);
 199         }
 200         if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
 201                 return (NULL);
 202
 203         return (wbuf);
 204 }
 205
 206 int
 207 imsg_add(struct ibuf *msg, void *data, u_int16_t datalen)
 208 {
 209         if (datalen)
 210                 if (ibuf_add(msg, data, datalen) == -1) {
 211                         ibuf_free(msg);
 212                         return (-1);
 213                 }
 214         return (datalen);
 215 }
 216
 217 void
 218 imsg_close(struct imsgbuf *ibuf, struct ibuf *msg)
 219 {
 220         struct imsg_hdr *hdr;
 221
 222         hdr = (struct imsg_hdr *)msg->buf;
 223
 224         hdr->flags &= ~IMSGF_HASFD;
 225         if (msg->fd != -1)
 226                 hdr->flags |= IMSGF_HASFD;
 227
 228         hdr->len = (u_int16_t)msg->wpos;
 229
 230         ibuf_close(&ibuf->w, msg);
 231 }
 232
 233 void
 234 imsg_free(struct imsg *imsg)
 235 {
 236         free(imsg->data);
 237 }
 238
 239 int
 240 imsg_get_fd(struct imsgbuf *ibuf)
 241 {
 242         int              fd;
 243         struct imsg_fd  *ifd;
 244
 245         if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
 246                 return (-1);
 247
 248         fd = ifd->fd;
 249         TAILQ_REMOVE(&ibuf->fds, ifd, entry);
 250         free(ifd);
 251
 252         return (fd);
 253 }
 254
 255 int
 256 imsg_flush(struct imsgbuf *ibuf)
 257 {
 258         while (ibuf->w.queued)
 259                 if (msgbuf_write(&ibuf->w) < 0)
 260                         return (-1);
 261         return (0);
 262 }
 263
 264 void
 265 imsg_clear(struct imsgbuf *ibuf)
 266 {
 267         int     fd;
 268
 269         msgbuf_clear(&ibuf->w);
 270         while ((fd = imsg_get_fd(ibuf)) != -1)
 271                 close(fd);
 272 }