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
imsg_init(struct imsgbuf * ibuf,int fd)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
imsg_read(struct imsgbuf * ibuf)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
imsg_get(struct imsgbuf * ibuf,struct imsg * imsg)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
imsg_compose(struct imsgbuf * ibuf,u_int32_t type,u_int32_t peerid,pid_t pid,int fd,void * data,u_int16_t datalen)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
imsg_composev(struct imsgbuf * ibuf,u_int32_t type,u_int32_t peerid,pid_t pid,int fd,const struct iovec * iov,int iovcnt)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 *
imsg_create(struct imsgbuf * ibuf,u_int32_t type,u_int32_t peerid,pid_t pid,u_int16_t datalen)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
imsg_add(struct ibuf * msg,void * data,u_int16_t datalen)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
imsg_close(struct imsgbuf * ibuf,struct ibuf * msg)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
imsg_free(struct imsg * imsg)234 imsg_free(struct imsg *imsg)
235 {
236 free(imsg->data);
237 }
238
239 int
imsg_get_fd(struct imsgbuf * ibuf)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
imsg_flush(struct imsgbuf * ibuf)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
imsg_clear(struct imsgbuf * ibuf)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