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 "../config.h"
21 #include <sys/types.h>
22 #include <sys/socket.h>
33 static int ibuf_realloc(struct ibuf *, size_t);
34 static void ibuf_enqueue(struct msgbuf *, struct ibuf *);
35 static void ibuf_dequeue(struct msgbuf *, struct ibuf *);
36 static void msgbuf_drain(struct msgbuf *, size_t);
47 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
49 if ((buf->buf = calloc(len, 1)) == NULL) {
53 buf->size = buf->max = len;
60 ibuf_dynamic(size_t len, size_t max)
69 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
72 if ((buf->buf = calloc(len, 1)) == NULL) {
85 ibuf_realloc(struct ibuf *buf, size_t len)
89 /* on static buffers max is eq size and so the following fails */
90 if (len > SIZE_MAX - buf->wpos || buf->wpos + len > buf->max) {
95 b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
99 buf->size = buf->wpos + len;
105 ibuf_reserve(struct ibuf *buf, size_t len)
109 if (len > SIZE_MAX - buf->wpos) {
114 if (buf->wpos + len > buf->size)
115 if (ibuf_realloc(buf, len) == -1)
118 b = buf->buf + buf->wpos;
125 ibuf_add(struct ibuf *buf, const void *data, size_t len)
129 if ((b = ibuf_reserve(buf, len)) == NULL)
132 memcpy(b, data, len);
137 ibuf_add_buf(struct ibuf *buf, const struct ibuf *from)
139 return ibuf_add(buf, from->buf, from->wpos);
143 ibuf_add_n8(struct ibuf *buf, uint64_t value)
147 if (value > UINT8_MAX) {
152 return ibuf_add(buf, &v, sizeof(v));
156 ibuf_add_n16(struct ibuf *buf, uint64_t value)
160 if (value > UINT16_MAX) {
165 return ibuf_add(buf, &v, sizeof(v));
169 ibuf_add_n32(struct ibuf *buf, uint64_t value)
173 if (value > UINT32_MAX) {
178 return ibuf_add(buf, &v, sizeof(v));
182 ibuf_add_n64(struct ibuf *buf, uint64_t value)
184 value = htobe64(value);
185 return ibuf_add(buf, &value, sizeof(value));
189 ibuf_add_zero(struct ibuf *buf, size_t len)
193 if ((b = ibuf_reserve(buf, len)) == NULL)
199 ibuf_seek(struct ibuf *buf, size_t pos, size_t len)
201 /* only allowed to seek in already written parts */
202 if (len > SIZE_MAX - pos || pos + len > buf->wpos) {
207 return (buf->buf + pos);
211 ibuf_set(struct ibuf *buf, size_t pos, const void *data, size_t len)
215 if ((b = ibuf_seek(buf, pos, len)) == NULL)
218 memcpy(b, data, len);
223 ibuf_set_n8(struct ibuf *buf, size_t pos, uint64_t value)
227 if (value > UINT8_MAX) {
232 return (ibuf_set(buf, pos, &v, sizeof(v)));
236 ibuf_set_n16(struct ibuf *buf, size_t pos, uint64_t value)
240 if (value > UINT16_MAX) {
245 return (ibuf_set(buf, pos, &v, sizeof(v)));
249 ibuf_set_n32(struct ibuf *buf, size_t pos, uint64_t value)
253 if (value > UINT32_MAX) {
258 return (ibuf_set(buf, pos, &v, sizeof(v)));
262 ibuf_set_n64(struct ibuf *buf, size_t pos, uint64_t value)
264 value = htobe64(value);
265 return (ibuf_set(buf, pos, &value, sizeof(value)));
269 ibuf_data(struct ibuf *buf)
275 ibuf_size(struct ibuf *buf)
281 ibuf_left(struct ibuf *buf)
283 return (buf->max - buf->wpos);
287 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
289 ibuf_enqueue(msgbuf, buf);
293 ibuf_free(struct ibuf *buf)
301 freezero(buf->buf, buf->size);
306 ibuf_fd_avail(struct ibuf *buf)
308 return (buf->fd != -1);
312 ibuf_fd_get(struct ibuf *buf)
324 ibuf_fd_set(struct ibuf *buf, int fd)
332 ibuf_write(struct msgbuf *msgbuf)
334 struct iovec iov[IOV_MAX];
339 memset(&iov, 0, sizeof(iov));
340 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
343 iov[i].iov_base = buf->buf + buf->rpos;
344 iov[i].iov_len = buf->wpos - buf->rpos;
349 if ((n = writev(msgbuf->fd, iov, i)) == -1) {
352 if (errno == ENOBUFS)
357 if (n == 0) { /* connection closed */
362 msgbuf_drain(msgbuf, n);
368 msgbuf_init(struct msgbuf *msgbuf)
372 TAILQ_INIT(&msgbuf->bufs);
376 msgbuf_drain(struct msgbuf *msgbuf, size_t n)
378 struct ibuf *buf, *next;
380 for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
382 next = TAILQ_NEXT(buf, entry);
383 if (n >= buf->wpos - buf->rpos) {
384 n -= buf->wpos - buf->rpos;
385 ibuf_dequeue(msgbuf, buf);
394 msgbuf_clear(struct msgbuf *msgbuf)
398 while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
399 ibuf_dequeue(msgbuf, buf);
403 msgbuf_write(struct msgbuf *msgbuf)
405 struct iovec iov[IOV_MAX];
406 struct ibuf *buf, *buf0 = NULL;
410 struct cmsghdr *cmsg;
413 char buf[CMSG_SPACE(sizeof(int))];
416 memset(&iov, 0, sizeof(iov));
417 memset(&msg, 0, sizeof(msg));
418 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
419 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
422 if (i > 0 && buf->fd != -1)
424 iov[i].iov_base = buf->buf + buf->rpos;
425 iov[i].iov_len = buf->wpos - buf->rpos;
435 msg.msg_control = (caddr_t)&cmsgbuf.buf;
436 msg.msg_controllen = sizeof(cmsgbuf.buf);
437 cmsg = CMSG_FIRSTHDR(&msg);
438 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
439 cmsg->cmsg_level = SOL_SOCKET;
440 cmsg->cmsg_type = SCM_RIGHTS;
441 *(int *)CMSG_DATA(cmsg) = buf0->fd;
445 if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
448 if (errno == ENOBUFS)
453 if (n == 0) { /* connection closed */
459 * assumption: fd got sent if sendmsg sent anything
460 * this works because fds are passed one at a time
467 msgbuf_drain(msgbuf, n);
473 ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
475 TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
480 ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
482 TAILQ_REMOVE(&msgbuf->bufs, buf, entry);