1 /* $OpenBSD: imsg-buffer.c,v 1.13 2021/03/31 17:42:24 eric 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.
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 *);
42 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
44 if ((buf->buf = malloc(len)) == NULL) {
48 buf->size = buf->max = len;
55 ibuf_dynamic(size_t len, size_t max)
62 if ((buf = ibuf_open(len)) == NULL)
72 ibuf_realloc(struct ibuf *buf, size_t len)
76 /* on static buffers max is eq size and so the following fails */
77 if (buf->wpos + len > buf->max) {
82 b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
86 buf->size = buf->wpos + len;
92 ibuf_add(struct ibuf *buf, const void *data, size_t len)
94 if (buf->wpos + len > buf->size)
95 if (ibuf_realloc(buf, len) == -1)
98 memcpy(buf->buf + buf->wpos, data, len);
104 ibuf_reserve(struct ibuf *buf, size_t len)
108 if (buf->wpos + len > buf->size)
109 if (ibuf_realloc(buf, len) == -1)
112 b = buf->buf + buf->wpos;
118 ibuf_seek(struct ibuf *buf, size_t pos, size_t len)
120 /* only allowed to seek in already written parts */
121 if (pos + len > buf->wpos)
124 return (buf->buf + pos);
128 ibuf_size(struct ibuf *buf)
134 ibuf_left(struct ibuf *buf)
136 return (buf->max - buf->wpos);
140 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
142 ibuf_enqueue(msgbuf, buf);
146 ibuf_write(struct msgbuf *msgbuf)
148 struct iovec iov[IOV_MAX];
153 memset(&iov, 0, sizeof(iov));
154 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
157 iov[i].iov_base = buf->buf + buf->rpos;
158 iov[i].iov_len = buf->wpos - buf->rpos;
163 if ((n = writev(msgbuf->fd, iov, i)) == -1) {
166 if (errno == ENOBUFS)
171 if (n == 0) { /* connection closed */
176 msgbuf_drain(msgbuf, n);
182 ibuf_free(struct ibuf *buf)
186 freezero(buf->buf, buf->size);
191 msgbuf_init(struct msgbuf *msgbuf)
195 TAILQ_INIT(&msgbuf->bufs);
199 msgbuf_drain(struct msgbuf *msgbuf, size_t n)
201 struct ibuf *buf, *next;
203 for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
205 next = TAILQ_NEXT(buf, entry);
206 if (buf->rpos + n >= buf->wpos) {
207 n -= buf->wpos - buf->rpos;
208 ibuf_dequeue(msgbuf, buf);
217 msgbuf_clear(struct msgbuf *msgbuf)
221 while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
222 ibuf_dequeue(msgbuf, buf);
226 msgbuf_write(struct msgbuf *msgbuf)
228 struct iovec iov[IOV_MAX];
229 struct ibuf *buf, *buf0 = NULL;
233 struct cmsghdr *cmsg;
236 char buf[CMSG_SPACE(sizeof(int))];
239 memset(&iov, 0, sizeof(iov));
240 memset(&msg, 0, sizeof(msg));
241 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
242 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
245 if (i > 0 && buf->fd != -1)
247 iov[i].iov_base = buf->buf + buf->rpos;
248 iov[i].iov_len = buf->wpos - buf->rpos;
258 msg.msg_control = (caddr_t)&cmsgbuf.buf;
259 msg.msg_controllen = sizeof(cmsgbuf.buf);
260 cmsg = CMSG_FIRSTHDR(&msg);
261 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
262 cmsg->cmsg_level = SOL_SOCKET;
263 cmsg->cmsg_type = SCM_RIGHTS;
264 *(int *)CMSG_DATA(cmsg) = buf0->fd;
268 if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
271 if (errno == ENOBUFS)
276 if (n == 0) { /* connection closed */
282 * assumption: fd got sent if sendmsg sent anything
283 * this works because fds are passed one at a time
290 msgbuf_drain(msgbuf, n);
296 ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
298 TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
303 ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
305 TAILQ_REMOVE(&msgbuf->bufs, buf, entry);