1 /* $OpenBSD: imsg.c,v 1.23 2023/12/12 15:47:41 claudio Exp $ */
4 * Copyright (c) 2023 Claudio Jeker <claudio@openbsd.org>
5 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
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.
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.
20 #include <sys/types.h>
21 #include <sys/socket.h>
33 TAILQ_ENTRY(imsg_fd
) entry
;
37 int imsg_fd_overhead
= 0;
39 static int imsg_dequeue_fd(struct imsgbuf
*);
42 imsg_init(struct imsgbuf
*imsgbuf
, int fd
)
44 msgbuf_init(&imsgbuf
->w
);
45 memset(&imsgbuf
->r
, 0, sizeof(imsgbuf
->r
));
48 imsgbuf
->pid
= getpid();
49 TAILQ_INIT(&imsgbuf
->fds
);
53 imsg_read(struct imsgbuf
*imsgbuf
)
59 char buf
[CMSG_SPACE(sizeof(int) * 1)];
66 memset(&msg
, 0, sizeof(msg
));
67 memset(&cmsgbuf
, 0, sizeof(cmsgbuf
));
69 iov
.iov_base
= imsgbuf
->r
.buf
+ imsgbuf
->r
.wpos
;
70 iov
.iov_len
= sizeof(imsgbuf
->r
.buf
) - imsgbuf
->r
.wpos
;
73 msg
.msg_control
= &cmsgbuf
.buf
;
74 msg
.msg_controllen
= sizeof(cmsgbuf
.buf
);
76 if ((ifd
= calloc(1, sizeof(struct imsg_fd
))) == NULL
)
80 if (getdtablecount() + imsg_fd_overhead
+
81 (int)((CMSG_SPACE(sizeof(int))-CMSG_SPACE(0))/sizeof(int))
88 if ((n
= recvmsg(imsgbuf
->fd
, &msg
, 0)) == -1) {
96 for (cmsg
= CMSG_FIRSTHDR(&msg
); cmsg
!= NULL
;
97 cmsg
= CMSG_NXTHDR(&msg
, cmsg
)) {
98 if (cmsg
->cmsg_level
== SOL_SOCKET
&&
99 cmsg
->cmsg_type
== SCM_RIGHTS
) {
104 * We only accept one file descriptor. Due to C
105 * padding rules, our control buffer might contain
106 * more than one fd, and we must close them.
108 j
= ((char *)cmsg
+ cmsg
->cmsg_len
-
109 (char *)CMSG_DATA(cmsg
)) / sizeof(int);
110 for (i
= 0; i
< j
; i
++) {
111 fd
= ((int *)CMSG_DATA(cmsg
))[i
];
114 TAILQ_INSERT_TAIL(&imsgbuf
->fds
, ifd
,
121 /* we do not handle other ctl data level */
130 imsg_get(struct imsgbuf
*imsgbuf
, struct imsg
*imsg
)
133 size_t av
, left
, datalen
;
135 av
= imsgbuf
->r
.wpos
;
137 if (IMSG_HEADER_SIZE
> av
)
140 memcpy(&m
.hdr
, imsgbuf
->r
.buf
, sizeof(m
.hdr
));
141 if (m
.hdr
.len
< IMSG_HEADER_SIZE
||
142 m
.hdr
.len
> MAX_IMSGSIZE
) {
153 datalen
= m
.hdr
.len
- IMSG_HEADER_SIZE
;
154 imsgbuf
->r
.rptr
= imsgbuf
->r
.buf
+ IMSG_HEADER_SIZE
;
156 if ((m
.buf
= ibuf_open(datalen
)) == NULL
)
158 if (ibuf_add(m
.buf
, imsgbuf
->r
.rptr
, datalen
) == -1) {
159 /* this should never fail */
163 m
.data
= ibuf_data(m
.buf
);
166 if (m
.hdr
.flags
& IMSGF_HASFD
)
167 m
.fd
= imsg_dequeue_fd(imsgbuf
);
169 if (m
.hdr
.len
< av
) {
170 left
= av
- m
.hdr
.len
;
171 memmove(&imsgbuf
->r
.buf
, imsgbuf
->r
.buf
+ m
.hdr
.len
, left
);
172 imsgbuf
->r
.wpos
= left
;
177 return (datalen
+ IMSG_HEADER_SIZE
);
181 imsg_get_ibuf(struct imsg
*imsg
, struct ibuf
*ibuf
)
183 if (imsg
->buf
== NULL
) {
187 return ibuf_get_ibuf(imsg
->buf
, ibuf_size(imsg
->buf
), ibuf
);
191 imsg_get_data(struct imsg
*imsg
, void *data
, size_t len
)
197 if (imsg
->buf
== NULL
|| ibuf_size(imsg
->buf
) != len
) {
201 return ibuf_get(imsg
->buf
, data
, len
);
205 imsg_get_fd(struct imsg
*imsg
)
214 imsg_get_id(struct imsg
*imsg
)
216 return (imsg
->hdr
.peerid
);
220 imsg_get_len(struct imsg
*imsg
)
222 if (imsg
->buf
== NULL
)
224 return ibuf_size(imsg
->buf
);
228 imsg_get_pid(struct imsg
*imsg
)
230 return (imsg
->hdr
.pid
);
234 imsg_get_type(struct imsg
*imsg
)
236 return (imsg
->hdr
.type
);
240 imsg_compose(struct imsgbuf
*imsgbuf
, uint32_t type
, uint32_t id
, pid_t pid
,
241 int fd
, const void *data
, size_t datalen
)
245 if ((wbuf
= imsg_create(imsgbuf
, type
, id
, pid
, datalen
)) == NULL
)
248 if (imsg_add(wbuf
, data
, datalen
) == -1)
251 ibuf_fd_set(wbuf
, fd
);
252 imsg_close(imsgbuf
, wbuf
);
258 imsg_composev(struct imsgbuf
*imsgbuf
, uint32_t type
, uint32_t id
, pid_t pid
,
259 int fd
, const struct iovec
*iov
, int iovcnt
)
265 for (i
= 0; i
< iovcnt
; i
++)
266 datalen
+= iov
[i
].iov_len
;
268 if ((wbuf
= imsg_create(imsgbuf
, type
, id
, pid
, datalen
)) == NULL
)
271 for (i
= 0; i
< iovcnt
; i
++)
272 if (imsg_add(wbuf
, iov
[i
].iov_base
, iov
[i
].iov_len
) == -1)
275 ibuf_fd_set(wbuf
, fd
);
276 imsg_close(imsgbuf
, wbuf
);
282 * Enqueue imsg with payload from ibuf buf. fd passing is not possible
283 * with this function.
286 imsg_compose_ibuf(struct imsgbuf
*imsgbuf
, uint32_t type
, uint32_t id
,
287 pid_t pid
, struct ibuf
*buf
)
289 struct ibuf
*hdrbuf
= NULL
;
293 if (ibuf_size(buf
) + IMSG_HEADER_SIZE
> MAX_IMSGSIZE
) {
299 hdr
.len
= ibuf_size(buf
) + IMSG_HEADER_SIZE
;
302 if ((hdr
.pid
= pid
) == 0)
303 hdr
.pid
= imsgbuf
->pid
;
305 if ((hdrbuf
= ibuf_open(IMSG_HEADER_SIZE
)) == NULL
)
307 if (imsg_add(hdrbuf
, &hdr
, sizeof(hdr
)) == -1)
310 ibuf_close(&imsgbuf
->w
, hdrbuf
);
311 ibuf_close(&imsgbuf
->w
, buf
);
323 * Forward imsg to another channel. Any attached fd is closed.
326 imsg_forward(struct imsgbuf
*imsgbuf
, struct imsg
*msg
)
336 if (msg
->buf
!= NULL
) {
337 ibuf_rewind(msg
->buf
);
338 len
= ibuf_size(msg
->buf
);
341 if ((wbuf
= imsg_create(imsgbuf
, msg
->hdr
.type
, msg
->hdr
.peerid
,
342 msg
->hdr
.pid
, len
)) == NULL
)
345 if (msg
->buf
!= NULL
) {
346 if (ibuf_add_buf(wbuf
, msg
->buf
) == -1) {
352 imsg_close(imsgbuf
, wbuf
);
357 imsg_create(struct imsgbuf
*imsgbuf
, uint32_t type
, uint32_t id
, pid_t pid
,
363 datalen
+= IMSG_HEADER_SIZE
;
364 if (datalen
> MAX_IMSGSIZE
) {
372 if ((hdr
.pid
= pid
) == 0)
373 hdr
.pid
= imsgbuf
->pid
;
374 if ((wbuf
= ibuf_dynamic(datalen
, MAX_IMSGSIZE
)) == NULL
) {
377 if (imsg_add(wbuf
, &hdr
, sizeof(hdr
)) == -1)
384 imsg_add(struct ibuf
*msg
, const void *data
, size_t datalen
)
387 if (ibuf_add(msg
, data
, datalen
) == -1) {
395 imsg_close(struct imsgbuf
*imsgbuf
, struct ibuf
*msg
)
397 struct imsg_hdr
*hdr
;
399 hdr
= (struct imsg_hdr
*)msg
->buf
;
401 hdr
->flags
&= ~IMSGF_HASFD
;
402 if (ibuf_fd_avail(msg
))
403 hdr
->flags
|= IMSGF_HASFD
;
404 hdr
->len
= ibuf_size(msg
);
406 ibuf_close(&imsgbuf
->w
, msg
);
410 imsg_free(struct imsg
*imsg
)
412 ibuf_free(imsg
->buf
);
416 imsg_dequeue_fd(struct imsgbuf
*imsgbuf
)
421 if ((ifd
= TAILQ_FIRST(&imsgbuf
->fds
)) == NULL
)
425 TAILQ_REMOVE(&imsgbuf
->fds
, ifd
, entry
);
432 imsg_flush(struct imsgbuf
*imsgbuf
)
434 while (imsgbuf
->w
.queued
)
435 if (msgbuf_write(&imsgbuf
->w
) <= 0)
441 imsg_clear(struct imsgbuf
*imsgbuf
)
445 msgbuf_clear(&imsgbuf
->w
);
446 while ((fd
= imsg_dequeue_fd(imsgbuf
)) != -1)