1 /* $OpenBSD: imsg.c,v 1.16 2017/12/14 09:27:44 kettenis Exp $ */
4 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 #include <sys/types.h>
22 #include <sys/socket.h>
32 int imsg_fd_overhead = 0;
34 static int imsg_get_fd(struct imsgbuf *);
37 imsg_init(struct imsgbuf *ibuf, int fd)
39 msgbuf_init(&ibuf->w);
40 memset(&ibuf->r, 0, sizeof(ibuf->r));
44 TAILQ_INIT(&ibuf->fds);
48 imsg_read(struct imsgbuf *ibuf)
54 char buf[CMSG_SPACE(sizeof(int) * 1)];
61 memset(&msg, 0, sizeof(msg));
62 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
64 iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
65 iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
68 msg.msg_control = &cmsgbuf.buf;
69 msg.msg_controllen = sizeof(cmsgbuf.buf);
71 if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
75 if (getdtablecount() + imsg_fd_overhead +
76 (int)((CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int))
83 if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
91 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
92 cmsg = CMSG_NXTHDR(&msg, cmsg)) {
93 if (cmsg->cmsg_level == SOL_SOCKET &&
94 cmsg->cmsg_type == SCM_RIGHTS) {
99 * We only accept one file descriptor. Due to C
100 * padding rules, our control buffer might contain
101 * more than one fd, and we must close them.
103 j = ((char *)cmsg + cmsg->cmsg_len -
104 (char *)CMSG_DATA(cmsg)) / sizeof(int);
105 for (i = 0; i < j; i++) {
106 fd = ((int *)CMSG_DATA(cmsg))[i];
109 TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
116 /* we do not handle other ctl data level */
125 imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
127 size_t av, left, datalen;
131 if (IMSG_HEADER_SIZE > av)
134 memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
135 if (imsg->hdr.len < IMSG_HEADER_SIZE ||
136 imsg->hdr.len > MAX_IMSGSIZE) {
140 if (imsg->hdr.len > av)
142 datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
143 ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
146 else if ((imsg->data = malloc(datalen)) == NULL)
149 if (imsg->hdr.flags & IMSGF_HASFD)
150 imsg->fd = imsg_get_fd(ibuf);
154 memcpy(imsg->data, ibuf->r.rptr, datalen);
156 if (imsg->hdr.len < av) {
157 left = av - imsg->hdr.len;
158 memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
163 return (datalen + IMSG_HEADER_SIZE);
167 imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
168 int fd, const void *data, uint16_t datalen)
172 if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
175 if (imsg_add(wbuf, data, datalen) == -1)
180 imsg_close(ibuf, wbuf);
186 imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
187 int fd, const struct iovec *iov, int iovcnt)
192 for (i = 0; i < iovcnt; i++)
193 datalen += iov[i].iov_len;
195 if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
198 for (i = 0; i < iovcnt; i++)
199 if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
204 imsg_close(ibuf, wbuf);
211 imsg_create(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
217 datalen += IMSG_HEADER_SIZE;
218 if (datalen > MAX_IMSGSIZE) {
226 if ((hdr.pid = pid) == 0)
228 if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
231 if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
238 imsg_add(struct ibuf *msg, const void *data, uint16_t datalen)
241 if (ibuf_add(msg, data, datalen) == -1) {
249 imsg_close(struct imsgbuf *ibuf, struct ibuf *msg)
251 struct imsg_hdr *hdr;
253 hdr = (struct imsg_hdr *)msg->buf;
255 hdr->flags &= ~IMSGF_HASFD;
257 hdr->flags |= IMSGF_HASFD;
259 hdr->len = (uint16_t)msg->wpos;
261 ibuf_close(&ibuf->w, msg);
265 imsg_free(struct imsg *imsg)
267 freezero(imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE);
271 imsg_get_fd(struct imsgbuf *ibuf)
276 if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
280 TAILQ_REMOVE(&ibuf->fds, ifd, entry);
287 imsg_flush(struct imsgbuf *ibuf)
289 while (ibuf->w.queued)
290 if (msgbuf_write(&ibuf->w) <= 0)
296 imsg_clear(struct imsgbuf *ibuf)
300 msgbuf_clear(&ibuf->w);
301 while ((fd = imsg_get_fd(ibuf)) != -1)