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.
19 #include <sys/types.h>
20 #include <sys/socket.h>
28 #include "got_compat.h"
31 int imsg_fd_overhead = 0;
33 static int imsg_get_fd(struct imsgbuf *);
36 imsg_init(struct imsgbuf *ibuf, int fd)
38 msgbuf_init(&ibuf->w);
39 memset(&ibuf->r, 0, sizeof(ibuf->r));
43 TAILQ_INIT(&ibuf->fds);
47 imsg_read(struct imsgbuf *ibuf)
53 char buf[CMSG_SPACE(sizeof(int) * 1)];
60 memset(&msg, 0, sizeof(msg));
61 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
63 iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
64 iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
67 msg.msg_control = &cmsgbuf.buf;
68 msg.msg_controllen = sizeof(cmsgbuf.buf);
70 if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
74 if (getdtablecount() + imsg_fd_overhead +
75 (int)((CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int))
82 if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
90 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
91 cmsg = CMSG_NXTHDR(&msg, cmsg)) {
92 if (cmsg->cmsg_level == SOL_SOCKET &&
93 cmsg->cmsg_type == SCM_RIGHTS) {
98 * We only accept one file descriptor. Due to C
99 * padding rules, our control buffer might contain
100 * more than one fd, and we must close them.
102 j = ((char *)cmsg + cmsg->cmsg_len -
103 (char *)CMSG_DATA(cmsg)) / sizeof(int);
104 for (i = 0; i < j; i++) {
105 fd = ((int *)CMSG_DATA(cmsg))[i];
108 TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
115 /* we do not handle other ctl data level */
124 imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
126 size_t av, left, datalen;
130 if (IMSG_HEADER_SIZE > av)
133 memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
134 if (imsg->hdr.len < IMSG_HEADER_SIZE ||
135 imsg->hdr.len > MAX_IMSGSIZE) {
139 if (imsg->hdr.len > av)
141 datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
142 ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
145 else if ((imsg->data = malloc(datalen)) == NULL)
148 if (imsg->hdr.flags & IMSGF_HASFD)
149 imsg->fd = imsg_get_fd(ibuf);
153 memcpy(imsg->data, ibuf->r.rptr, datalen);
155 if (imsg->hdr.len < av) {
156 left = av - imsg->hdr.len;
157 memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
162 return (datalen + IMSG_HEADER_SIZE);
166 imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
167 int fd, const void *data, uint16_t datalen)
171 if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
174 if (imsg_add(wbuf, data, datalen) == -1)
179 imsg_close(ibuf, wbuf);
185 imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
186 int fd, const struct iovec *iov, int iovcnt)
191 for (i = 0; i < iovcnt; i++)
192 datalen += iov[i].iov_len;
194 if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
197 for (i = 0; i < iovcnt; i++)
198 if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
203 imsg_close(ibuf, wbuf);
210 imsg_create(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
216 datalen += IMSG_HEADER_SIZE;
217 if (datalen > MAX_IMSGSIZE) {
225 if ((hdr.pid = pid) == 0)
227 if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
230 if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
237 imsg_add(struct ibuf *msg, const void *data, uint16_t datalen)
240 if (ibuf_add(msg, data, datalen) == -1) {
248 imsg_close(struct imsgbuf *ibuf, struct ibuf *msg)
250 struct imsg_hdr *hdr;
252 hdr = (struct imsg_hdr *)msg->buf;
254 hdr->flags &= ~IMSGF_HASFD;
256 hdr->flags |= IMSGF_HASFD;
258 hdr->len = (uint16_t)msg->wpos;
260 ibuf_close(&ibuf->w, msg);
264 imsg_free(struct imsg *imsg)
266 freezero(imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE);
270 imsg_get_fd(struct imsgbuf *ibuf)
275 if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
279 TAILQ_REMOVE(&ibuf->fds, ifd, entry);
286 imsg_flush(struct imsgbuf *ibuf)
288 while (ibuf->w.queued)
289 if (msgbuf_write(&ibuf->w) <= 0)
295 imsg_clear(struct imsgbuf *ibuf)
299 msgbuf_clear(&ibuf->w);
300 while ((fd = imsg_get_fd(ibuf)) != -1)