1 /* $OpenBSD: imsg-buffer.c,v 1.16 2023/06/19 17:19:50 claudio 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>
29 #include "got_compat.h"
32 static int ibuf_realloc(struct ibuf *, size_t);
33 static void ibuf_enqueue(struct msgbuf *, struct ibuf *);
34 static void ibuf_dequeue(struct msgbuf *, struct ibuf *);
35 static void msgbuf_drain(struct msgbuf *, size_t);
46 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
48 if ((buf->buf = calloc(len, 1)) == NULL) {
52 buf->size = buf->max = len;
59 ibuf_dynamic(size_t len, size_t max)
68 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
71 if ((buf->buf = calloc(len, 1)) == NULL) {
84 ibuf_realloc(struct ibuf *buf, size_t len)
88 /* on static buffers max is eq size and so the following fails */
89 if (len > SIZE_MAX - buf->wpos || buf->wpos + len > buf->max) {
94 b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
98 buf->size = buf->wpos + len;
104 ibuf_reserve(struct ibuf *buf, size_t len)
108 if (len > SIZE_MAX - buf->wpos) {
113 if (buf->wpos + len > buf->size)
114 if (ibuf_realloc(buf, len) == -1)
117 b = buf->buf + buf->wpos;
124 ibuf_add(struct ibuf *buf, const void *data, size_t len)
128 if ((b = ibuf_reserve(buf, len)) == NULL)
131 memcpy(b, data, len);
136 ibuf_add_buf(struct ibuf *buf, const struct ibuf *from)
138 return ibuf_add(buf, from->buf, from->wpos);
142 ibuf_add_n8(struct ibuf *buf, uint64_t value)
146 if (value > UINT8_MAX) {
151 return ibuf_add(buf, &v, sizeof(v));
155 ibuf_add_n16(struct ibuf *buf, uint64_t value)
159 if (value > UINT16_MAX) {
164 return ibuf_add(buf, &v, sizeof(v));
168 ibuf_add_n32(struct ibuf *buf, uint64_t value)
172 if (value > UINT32_MAX) {
177 return ibuf_add(buf, &v, sizeof(v));
181 ibuf_add_n64(struct ibuf *buf, uint64_t value)
183 value = htobe64(value);
184 return ibuf_add(buf, &value, sizeof(value));
188 ibuf_add_zero(struct ibuf *buf, size_t len)
192 if ((b = ibuf_reserve(buf, len)) == NULL)
198 ibuf_seek(struct ibuf *buf, size_t pos, size_t len)
200 /* only allowed to seek in already written parts */
201 if (len > SIZE_MAX - pos || pos + len > buf->wpos) {
206 return (buf->buf + pos);
210 ibuf_set(struct ibuf *buf, size_t pos, const void *data, size_t len)
214 if ((b = ibuf_seek(buf, pos, len)) == NULL)
217 memcpy(b, data, len);
222 ibuf_set_n8(struct ibuf *buf, size_t pos, uint64_t value)
226 if (value > UINT8_MAX) {
231 return (ibuf_set(buf, pos, &v, sizeof(v)));
235 ibuf_set_n16(struct ibuf *buf, size_t pos, uint64_t value)
239 if (value > UINT16_MAX) {
244 return (ibuf_set(buf, pos, &v, sizeof(v)));
248 ibuf_set_n32(struct ibuf *buf, size_t pos, uint64_t value)
252 if (value > UINT32_MAX) {
257 return (ibuf_set(buf, pos, &v, sizeof(v)));
261 ibuf_set_n64(struct ibuf *buf, size_t pos, uint64_t value)
263 value = htobe64(value);
264 return (ibuf_set(buf, pos, &value, sizeof(value)));
268 ibuf_data(struct ibuf *buf)
274 ibuf_size(struct ibuf *buf)
280 ibuf_left(struct ibuf *buf)
282 return (buf->max - buf->wpos);
286 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
288 ibuf_enqueue(msgbuf, buf);
292 ibuf_free(struct ibuf *buf)
300 freezero(buf->buf, buf->size);
305 ibuf_fd_avail(struct ibuf *buf)
307 return (buf->fd != -1);
311 ibuf_fd_get(struct ibuf *buf)
323 ibuf_fd_set(struct ibuf *buf, int fd)
331 ibuf_write(struct msgbuf *msgbuf)
333 struct iovec iov[IOV_MAX];
338 memset(&iov, 0, sizeof(iov));
339 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
342 iov[i].iov_base = buf->buf + buf->rpos;
343 iov[i].iov_len = buf->wpos - buf->rpos;
348 if ((n = writev(msgbuf->fd, iov, i)) == -1) {
351 if (errno == ENOBUFS)
356 if (n == 0) { /* connection closed */
361 msgbuf_drain(msgbuf, n);
367 msgbuf_init(struct msgbuf *msgbuf)
371 TAILQ_INIT(&msgbuf->bufs);
375 msgbuf_drain(struct msgbuf *msgbuf, size_t n)
377 struct ibuf *buf, *next;
379 for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
381 next = TAILQ_NEXT(buf, entry);
382 if (n >= buf->wpos - buf->rpos) {
383 n -= buf->wpos - buf->rpos;
384 ibuf_dequeue(msgbuf, buf);
393 msgbuf_clear(struct msgbuf *msgbuf)
397 while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
398 ibuf_dequeue(msgbuf, buf);
402 msgbuf_write(struct msgbuf *msgbuf)
404 struct iovec iov[IOV_MAX];
405 struct ibuf *buf, *buf0 = NULL;
409 struct cmsghdr *cmsg;
412 char buf[CMSG_SPACE(sizeof(int))];
415 memset(&iov, 0, sizeof(iov));
416 memset(&msg, 0, sizeof(msg));
417 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
418 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
421 if (i > 0 && buf->fd != -1)
423 iov[i].iov_base = buf->buf + buf->rpos;
424 iov[i].iov_len = buf->wpos - buf->rpos;
434 msg.msg_control = (caddr_t)&cmsgbuf.buf;
435 msg.msg_controllen = sizeof(cmsgbuf.buf);
436 cmsg = CMSG_FIRSTHDR(&msg);
437 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
438 cmsg->cmsg_level = SOL_SOCKET;
439 cmsg->cmsg_type = SCM_RIGHTS;
440 *(int *)CMSG_DATA(cmsg) = buf0->fd;
444 if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
447 if (errno == ENOBUFS)
452 if (n == 0) { /* connection closed */
458 * assumption: fd got sent if sendmsg sent anything
459 * this works because fds are passed one at a time
466 msgbuf_drain(msgbuf, n);
472 ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
474 TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
479 ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
481 TAILQ_REMOVE(&msgbuf->bufs, buf, entry);