1 /* Id */ 2 /* $OpenBSD: imsg-buffer.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 ibuf_realloc(struct ibuf *, size_t); 33 void ibuf_enqueue(struct msgbuf *, struct ibuf *); 34 void ibuf_dequeue(struct msgbuf *, struct ibuf *); 35 36 struct ibuf * 37 ibuf_open(size_t len) 38 { 39 struct ibuf *buf; 40 41 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL) 42 return (NULL); 43 if ((buf->buf = malloc(len)) == NULL) { 44 free(buf); 45 return (NULL); 46 } 47 buf->size = buf->max = len; 48 buf->fd = -1; 49 50 return (buf); 51 } 52 53 struct ibuf * 54 ibuf_dynamic(size_t len, size_t max) 55 { 56 struct ibuf *buf; 57 58 if (max < len) 59 return (NULL); 60 61 if ((buf = ibuf_open(len)) == NULL) 62 return (NULL); 63 64 if (max > 0) 65 buf->max = max; 66 67 return (buf); 68 } 69 70 int 71 ibuf_realloc(struct ibuf *buf, size_t len) 72 { 73 u_char *b; 74 75 /* on static buffers max is eq size and so the following fails */ 76 if (buf->wpos + len > buf->max) { 77 errno = ENOMEM; 78 return (-1); 79 } 80 81 b = realloc(buf->buf, buf->wpos + len); 82 if (b == NULL) 83 return (-1); 84 buf->buf = b; 85 buf->size = buf->wpos + len; 86 87 return (0); 88 } 89 90 int 91 ibuf_add(struct ibuf *buf, const void *data, size_t len) 92 { 93 if (buf->wpos + len > buf->size) 94 if (ibuf_realloc(buf, len) == -1) 95 return (-1); 96 97 memcpy(buf->buf + buf->wpos, data, len); 98 buf->wpos += len; 99 return (0); 100 } 101 102 void * 103 ibuf_reserve(struct ibuf *buf, size_t len) 104 { 105 void *b; 106 107 if (buf->wpos + len > buf->size) 108 if (ibuf_realloc(buf, len) == -1) 109 return (NULL); 110 111 b = buf->buf + buf->wpos; 112 buf->wpos += len; 113 return (b); 114 } 115 116 void * 117 ibuf_seek(struct ibuf *buf, size_t pos, size_t len) 118 { 119 /* only allowed to seek in already written parts */ 120 if (pos + len > buf->wpos) 121 return (NULL); 122 123 return (buf->buf + pos); 124 } 125 126 size_t 127 ibuf_size(struct ibuf *buf) 128 { 129 return (buf->wpos); 130 } 131 132 size_t 133 ibuf_left(struct ibuf *buf) 134 { 135 return (buf->max - buf->wpos); 136 } 137 138 void 139 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf) 140 { 141 ibuf_enqueue(msgbuf, buf); 142 } 143 144 int 145 ibuf_write(struct msgbuf *msgbuf) 146 { 147 struct iovec iov[IOV_MAX]; 148 struct ibuf *buf; 149 unsigned int i = 0; 150 ssize_t n; 151 152 bzero(&iov, sizeof(iov)); 153 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) { 154 if (i >= IOV_MAX) 155 break; 156 iov[i].iov_base = buf->buf + buf->rpos; 157 iov[i].iov_len = buf->wpos - buf->rpos; 158 i++; 159 } 160 161 if ((n = writev(msgbuf->fd, iov, i)) == -1) { 162 if (errno == EAGAIN || errno == ENOBUFS || 163 errno == EINTR) /* try later */ 164 return (0); 165 else 166 return (-1); 167 } 168 169 if (n == 0) { /* connection closed */ 170 errno = 0; 171 return (-2); 172 } 173 174 msgbuf_drain(msgbuf, n); 175 176 return (0); 177 } 178 179 void 180 ibuf_free(struct ibuf *buf) 181 { 182 free(buf->buf); 183 free(buf); 184 } 185 186 void 187 msgbuf_init(struct msgbuf *msgbuf) 188 { 189 msgbuf->queued = 0; 190 msgbuf->fd = -1; 191 TAILQ_INIT(&msgbuf->bufs); 192 } 193 194 void 195 msgbuf_drain(struct msgbuf *msgbuf, size_t n) 196 { 197 struct ibuf *buf, *next; 198 199 for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0; 200 buf = next) { 201 next = TAILQ_NEXT(buf, entry); 202 if (buf->rpos + n >= buf->wpos) { 203 n -= buf->wpos - buf->rpos; 204 ibuf_dequeue(msgbuf, buf); 205 } else { 206 buf->rpos += n; 207 n = 0; 208 } 209 } 210 } 211 212 void 213 msgbuf_clear(struct msgbuf *msgbuf) 214 { 215 struct ibuf *buf; 216 217 while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL) 218 ibuf_dequeue(msgbuf, buf); 219 } 220 221 int 222 msgbuf_write(struct msgbuf *msgbuf) 223 { 224 struct iovec iov[IOV_MAX]; 225 struct ibuf *buf; 226 unsigned int i = 0; 227 ssize_t n; 228 struct msghdr msg; 229 struct cmsghdr *cmsg; 230 union { 231 struct cmsghdr hdr; 232 char buf[CMSG_SPACE(sizeof(int))]; 233 } cmsgbuf; 234 235 bzero(&iov, sizeof(iov)); 236 bzero(&msg, sizeof(msg)); 237 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) { 238 if (i >= IOV_MAX) 239 break; 240 iov[i].iov_base = buf->buf + buf->rpos; 241 iov[i].iov_len = buf->wpos - buf->rpos; 242 i++; 243 if (buf->fd != -1) 244 break; 245 } 246 247 msg.msg_iov = iov; 248 msg.msg_iovlen = i; 249 250 if (buf != NULL && buf->fd != -1) { 251 msg.msg_control = (caddr_t)&cmsgbuf.buf; 252 msg.msg_controllen = CMSG_SPACE(sizeof(int)); 253 cmsg = CMSG_FIRSTHDR(&msg); 254 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 255 cmsg->cmsg_level = SOL_SOCKET; 256 cmsg->cmsg_type = SCM_RIGHTS; 257 *(int *)CMSG_DATA(cmsg) = buf->fd; 258 } 259 260 if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) { 261 if (errno == EAGAIN || errno == ENOBUFS || 262 errno == EINTR) /* try later */ 263 return (0); 264 else 265 return (-1); 266 } 267 268 if (n == 0) { /* connection closed */ 269 errno = 0; 270 return (-2); 271 } 272 273 /* 274 * assumption: fd got sent if sendmsg sent anything 275 * this works because fds are passed one at a time 276 */ 277 if (buf != NULL && buf->fd != -1) { 278 close(buf->fd); 279 buf->fd = -1; 280 } 281 282 msgbuf_drain(msgbuf, n); 283 284 return (0); 285 } 286 287 void 288 ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf) 289 { 290 TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry); 291 msgbuf->queued++; 292 } 293 294 void 295 ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf) 296 { 297 TAILQ_REMOVE(&msgbuf->bufs, buf, entry); 298 299 if (buf->fd != -1) 300 close(buf->fd); 301 302 msgbuf->queued--; 303 ibuf_free(buf); 304 } 305