1 /* $OpenBSD: imsg-buffer.c,v 1.11 2017/12/14 09:27:44 kettenis 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"
31 static int ibuf_realloc(struct ibuf *, size_t);
32 static void ibuf_enqueue(struct msgbuf *, struct ibuf *);
33 static void ibuf_dequeue(struct msgbuf *, struct ibuf *);
40 if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
42 if ((buf->buf = malloc(len)) == NULL) {
46 buf->size = buf->max = len;
53 ibuf_dynamic(size_t len, size_t max)
60 if ((buf = ibuf_open(len)) == NULL)
70 ibuf_realloc(struct ibuf *buf, size_t len)
74 /* on static buffers max is eq size and so the following fails */
75 if (buf->wpos + len > buf->max) {
80 b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
84 buf->size = buf->wpos + len;
90 ibuf_add(struct ibuf *buf, const void *data, size_t len)
92 if (buf->wpos + len > buf->size)
93 if (ibuf_realloc(buf, len) == -1)
96 memcpy(buf->buf + buf->wpos, data, len);
102 ibuf_reserve(struct ibuf *buf, size_t len)
106 if (buf->wpos + len > buf->size)
107 if (ibuf_realloc(buf, len) == -1)
110 b = buf->buf + buf->wpos;
116 ibuf_seek(struct ibuf *buf, size_t pos, size_t len)
118 /* only allowed to seek in already written parts */
119 if (pos + len > buf->wpos)
122 return (buf->buf + pos);
126 ibuf_size(struct ibuf *buf)
132 ibuf_left(struct ibuf *buf)
134 return (buf->max - buf->wpos);
138 ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
140 ibuf_enqueue(msgbuf, buf);
144 ibuf_write(struct msgbuf *msgbuf)
146 struct iovec iov[IOV_MAX];
151 memset(&iov, 0, sizeof(iov));
152 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
155 iov[i].iov_base = buf->buf + buf->rpos;
156 iov[i].iov_len = buf->wpos - buf->rpos;
161 if ((n = writev(msgbuf->fd, iov, i)) == -1) {
164 if (errno == ENOBUFS)
169 if (n == 0) { /* connection closed */
174 msgbuf_drain(msgbuf, n);
180 ibuf_free(struct ibuf *buf)
184 freezero(buf->buf, buf->size);
189 msgbuf_init(struct msgbuf *msgbuf)
193 TAILQ_INIT(&msgbuf->bufs);
197 msgbuf_drain(struct msgbuf *msgbuf, size_t n)
199 struct ibuf *buf, *next;
201 for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
203 next = TAILQ_NEXT(buf, entry);
204 if (buf->rpos + n >= buf->wpos) {
205 n -= buf->wpos - buf->rpos;
206 ibuf_dequeue(msgbuf, buf);
215 msgbuf_clear(struct msgbuf *msgbuf)
219 while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
220 ibuf_dequeue(msgbuf, buf);
224 msgbuf_write(struct msgbuf *msgbuf)
226 struct iovec iov[IOV_MAX];
231 struct cmsghdr *cmsg;
234 char buf[CMSG_SPACE(sizeof(int))];
237 memset(&iov, 0, sizeof(iov));
238 memset(&msg, 0, sizeof(msg));
239 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
240 TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
243 iov[i].iov_base = buf->buf + buf->rpos;
244 iov[i].iov_len = buf->wpos - buf->rpos;
253 if (buf != NULL && buf->fd != -1) {
254 msg.msg_control = (caddr_t)&cmsgbuf.buf;
255 msg.msg_controllen = sizeof(cmsgbuf.buf);
256 cmsg = CMSG_FIRSTHDR(&msg);
257 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
258 cmsg->cmsg_level = SOL_SOCKET;
259 cmsg->cmsg_type = SCM_RIGHTS;
260 *(int *)CMSG_DATA(cmsg) = buf->fd;
264 if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
267 if (errno == ENOBUFS)
272 if (n == 0) { /* connection closed */
278 * assumption: fd got sent if sendmsg sent anything
279 * this works because fds are passed one at a time
281 if (buf != NULL && buf->fd != -1) {
286 msgbuf_drain(msgbuf, n);
292 ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
294 TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
299 ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
301 TAILQ_REMOVE(&msgbuf->bufs, buf, entry);