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 } 273