1 b0003f58 2021-03-08 op /* $OpenBSD: imsg.c,v 1.16 2017/12/14 09:27:44 kettenis Exp $ */
4 b0003f58 2021-03-08 op * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
6 b0003f58 2021-03-08 op * Permission to use, copy, modify, and distribute this software for any
7 b0003f58 2021-03-08 op * purpose with or without fee is hereby granted, provided that the above
8 b0003f58 2021-03-08 op * copyright notice and this permission notice appear in all copies.
10 b0003f58 2021-03-08 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 b0003f58 2021-03-08 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 b0003f58 2021-03-08 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 b0003f58 2021-03-08 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 b0003f58 2021-03-08 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 b0003f58 2021-03-08 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 b0003f58 2021-03-08 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 b0003f58 2021-03-08 op #include <sys/types.h>
20 b0003f58 2021-03-08 op #include <sys/socket.h>
21 b0003f58 2021-03-08 op #include <sys/uio.h>
23 b0003f58 2021-03-08 op #include <errno.h>
24 b0003f58 2021-03-08 op #include <stdlib.h>
25 b0003f58 2021-03-08 op #include <string.h>
26 b0003f58 2021-03-08 op #include <unistd.h>
28 b0003f58 2021-03-08 op #include "imsg.h"
30 b0003f58 2021-03-08 op int imsg_fd_overhead = 0;
32 b0003f58 2021-03-08 op static int imsg_get_fd(struct imsgbuf *);
35 b0003f58 2021-03-08 op imsg_init(struct imsgbuf *ibuf, int fd)
37 b0003f58 2021-03-08 op msgbuf_init(&ibuf->w);
38 b0003f58 2021-03-08 op memset(&ibuf->r, 0, sizeof(ibuf->r));
39 b0003f58 2021-03-08 op ibuf->fd = fd;
40 b0003f58 2021-03-08 op ibuf->w.fd = fd;
41 b0003f58 2021-03-08 op ibuf->pid = getpid();
42 b0003f58 2021-03-08 op TAILQ_INIT(&ibuf->fds);
46 b0003f58 2021-03-08 op imsg_read(struct imsgbuf *ibuf)
48 b0003f58 2021-03-08 op struct msghdr msg;
49 b0003f58 2021-03-08 op struct cmsghdr *cmsg;
51 b0003f58 2021-03-08 op struct cmsghdr hdr;
52 b0003f58 2021-03-08 op char buf[CMSG_SPACE(sizeof(int) * 1)];
54 b0003f58 2021-03-08 op struct iovec iov;
55 b0003f58 2021-03-08 op ssize_t n = -1;
57 b0003f58 2021-03-08 op struct imsg_fd *ifd;
59 b0003f58 2021-03-08 op memset(&msg, 0, sizeof(msg));
60 b0003f58 2021-03-08 op memset(&cmsgbuf, 0, sizeof(cmsgbuf));
62 b0003f58 2021-03-08 op iov.iov_base = ibuf->r.buf + ibuf->r.wpos;
63 b0003f58 2021-03-08 op iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos;
64 b0003f58 2021-03-08 op msg.msg_iov = &iov;
65 b0003f58 2021-03-08 op msg.msg_iovlen = 1;
66 b0003f58 2021-03-08 op msg.msg_control = &cmsgbuf.buf;
67 b0003f58 2021-03-08 op msg.msg_controllen = sizeof(cmsgbuf.buf);
69 b0003f58 2021-03-08 op if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL)
73 b0003f58 2021-03-08 op if (getdtablecount() + imsg_fd_overhead +
74 b0003f58 2021-03-08 op (int)((CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int))
75 b0003f58 2021-03-08 op >= getdtablesize()) {
76 b0003f58 2021-03-08 op errno = EAGAIN;
81 b0003f58 2021-03-08 op if ((n = recvmsg(ibuf->fd, &msg, 0)) == -1) {
82 b0003f58 2021-03-08 op if (errno == EINTR)
87 b0003f58 2021-03-08 op ibuf->r.wpos += n;
89 b0003f58 2021-03-08 op for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
90 b0003f58 2021-03-08 op cmsg = CMSG_NXTHDR(&msg, cmsg)) {
91 b0003f58 2021-03-08 op if (cmsg->cmsg_level == SOL_SOCKET &&
92 b0003f58 2021-03-08 op cmsg->cmsg_type == SCM_RIGHTS) {
97 b0003f58 2021-03-08 op * We only accept one file descriptor. Due to C
98 b0003f58 2021-03-08 op * padding rules, our control buffer might contain
99 b0003f58 2021-03-08 op * more than one fd, and we must close them.
101 b0003f58 2021-03-08 op j = ((char *)cmsg + cmsg->cmsg_len -
102 b0003f58 2021-03-08 op (char *)CMSG_DATA(cmsg)) / sizeof(int);
103 b0003f58 2021-03-08 op for (i = 0; i < j; i++) {
104 b0003f58 2021-03-08 op fd = ((int *)CMSG_DATA(cmsg))[i];
105 b0003f58 2021-03-08 op if (ifd != NULL) {
106 b0003f58 2021-03-08 op ifd->fd = fd;
107 b0003f58 2021-03-08 op TAILQ_INSERT_TAIL(&ibuf->fds, ifd,
114 b0003f58 2021-03-08 op /* we do not handle other ctl data level */
123 b0003f58 2021-03-08 op imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
125 b0003f58 2021-03-08 op size_t av, left, datalen;
127 b0003f58 2021-03-08 op av = ibuf->r.wpos;
129 b0003f58 2021-03-08 op if (IMSG_HEADER_SIZE > av)
132 b0003f58 2021-03-08 op memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
133 b0003f58 2021-03-08 op if (imsg->hdr.len < IMSG_HEADER_SIZE ||
134 b0003f58 2021-03-08 op imsg->hdr.len > MAX_IMSGSIZE) {
135 b0003f58 2021-03-08 op errno = ERANGE;
138 b0003f58 2021-03-08 op if (imsg->hdr.len > av)
140 b0003f58 2021-03-08 op datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
141 b0003f58 2021-03-08 op ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
142 b0003f58 2021-03-08 op if (datalen == 0)
143 b0003f58 2021-03-08 op imsg->data = NULL;
144 b0003f58 2021-03-08 op else if ((imsg->data = malloc(datalen)) == NULL)
147 b0003f58 2021-03-08 op if (imsg->hdr.flags & IMSGF_HASFD)
148 b0003f58 2021-03-08 op imsg->fd = imsg_get_fd(ibuf);
150 b0003f58 2021-03-08 op imsg->fd = -1;
152 b0003f58 2021-03-08 op memcpy(imsg->data, ibuf->r.rptr, datalen);
154 b0003f58 2021-03-08 op if (imsg->hdr.len < av) {
155 b0003f58 2021-03-08 op left = av - imsg->hdr.len;
156 b0003f58 2021-03-08 op memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
157 b0003f58 2021-03-08 op ibuf->r.wpos = left;
159 b0003f58 2021-03-08 op ibuf->r.wpos = 0;
161 b0003f58 2021-03-08 op return (datalen + IMSG_HEADER_SIZE);
165 b0003f58 2021-03-08 op imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
166 b0003f58 2021-03-08 op int fd, const void *data, uint16_t datalen)
168 b0003f58 2021-03-08 op struct ibuf *wbuf;
170 b0003f58 2021-03-08 op if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
173 b0003f58 2021-03-08 op if (imsg_add(wbuf, data, datalen) == -1)
176 b0003f58 2021-03-08 op wbuf->fd = fd;
178 b0003f58 2021-03-08 op imsg_close(ibuf, wbuf);
184 b0003f58 2021-03-08 op imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
185 b0003f58 2021-03-08 op int fd, const struct iovec *iov, int iovcnt)
187 b0003f58 2021-03-08 op struct ibuf *wbuf;
188 b0003f58 2021-03-08 op int i, datalen = 0;
190 b0003f58 2021-03-08 op for (i = 0; i < iovcnt; i++)
191 b0003f58 2021-03-08 op datalen += iov[i].iov_len;
193 b0003f58 2021-03-08 op if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
196 b0003f58 2021-03-08 op for (i = 0; i < iovcnt; i++)
197 b0003f58 2021-03-08 op if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1)
200 b0003f58 2021-03-08 op wbuf->fd = fd;
202 b0003f58 2021-03-08 op imsg_close(ibuf, wbuf);
207 b0003f58 2021-03-08 op /* ARGSUSED */
208 b0003f58 2021-03-08 op struct ibuf *
209 b0003f58 2021-03-08 op imsg_create(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, pid_t pid,
210 b0003f58 2021-03-08 op uint16_t datalen)
212 b0003f58 2021-03-08 op struct ibuf *wbuf;
213 b0003f58 2021-03-08 op struct imsg_hdr hdr;
215 b0003f58 2021-03-08 op datalen += IMSG_HEADER_SIZE;
216 b0003f58 2021-03-08 op if (datalen > MAX_IMSGSIZE) {
217 b0003f58 2021-03-08 op errno = ERANGE;
218 b0003f58 2021-03-08 op return (NULL);
221 b0003f58 2021-03-08 op hdr.type = type;
222 b0003f58 2021-03-08 op hdr.flags = 0;
223 b0003f58 2021-03-08 op hdr.peerid = peerid;
224 b0003f58 2021-03-08 op if ((hdr.pid = pid) == 0)
225 b0003f58 2021-03-08 op hdr.pid = ibuf->pid;
226 b0003f58 2021-03-08 op if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) {
227 b0003f58 2021-03-08 op return (NULL);
229 b0003f58 2021-03-08 op if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
230 b0003f58 2021-03-08 op return (NULL);
232 b0003f58 2021-03-08 op return (wbuf);
236 b0003f58 2021-03-08 op imsg_add(struct ibuf *msg, const void *data, uint16_t datalen)
239 b0003f58 2021-03-08 op if (ibuf_add(msg, data, datalen) == -1) {
240 b0003f58 2021-03-08 op ibuf_free(msg);
243 b0003f58 2021-03-08 op return (datalen);
247 b0003f58 2021-03-08 op imsg_close(struct imsgbuf *ibuf, struct ibuf *msg)
249 b0003f58 2021-03-08 op struct imsg_hdr *hdr;
251 b0003f58 2021-03-08 op hdr = (struct imsg_hdr *)msg->buf;
253 b0003f58 2021-03-08 op hdr->flags &= ~IMSGF_HASFD;
254 b0003f58 2021-03-08 op if (msg->fd != -1)
255 b0003f58 2021-03-08 op hdr->flags |= IMSGF_HASFD;
257 b0003f58 2021-03-08 op hdr->len = (uint16_t)msg->wpos;
259 b0003f58 2021-03-08 op ibuf_close(&ibuf->w, msg);
263 b0003f58 2021-03-08 op imsg_free(struct imsg *imsg)
265 b0003f58 2021-03-08 op freezero(imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE);
269 b0003f58 2021-03-08 op imsg_get_fd(struct imsgbuf *ibuf)
272 b0003f58 2021-03-08 op struct imsg_fd *ifd;
274 b0003f58 2021-03-08 op if ((ifd = TAILQ_FIRST(&ibuf->fds)) == NULL)
277 b0003f58 2021-03-08 op fd = ifd->fd;
278 b0003f58 2021-03-08 op TAILQ_REMOVE(&ibuf->fds, ifd, entry);
285 b0003f58 2021-03-08 op imsg_flush(struct imsgbuf *ibuf)
287 b0003f58 2021-03-08 op while (ibuf->w.queued)
288 b0003f58 2021-03-08 op if (msgbuf_write(&ibuf->w) <= 0)
294 b0003f58 2021-03-08 op imsg_clear(struct imsgbuf *ibuf)
298 b0003f58 2021-03-08 op msgbuf_clear(&ibuf->w);
299 b0003f58 2021-03-08 op while ((fd = imsg_get_fd(ibuf)) != -1)