1 f229e009 2023-07-02 op /*	$OpenBSD: imsg-buffer.c,v 1.16 2023/06/19 17:19:50 claudio Exp $	*/
  2 bbcba3ed 2022-01-10 op 
  3 bbcba3ed 2022-01-10 op /*
  4 bbcba3ed 2022-01-10 op  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
  5 bbcba3ed 2022-01-10 op  *
  6 bbcba3ed 2022-01-10 op  * Permission to use, copy, modify, and distribute this software for any
  7 bbcba3ed 2022-01-10 op  * purpose with or without fee is hereby granted, provided that the above
  8 bbcba3ed 2022-01-10 op  * copyright notice and this permission notice appear in all copies.
  9 bbcba3ed 2022-01-10 op  *
 10 bbcba3ed 2022-01-10 op  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 11 bbcba3ed 2022-01-10 op  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 12 bbcba3ed 2022-01-10 op  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 13 bbcba3ed 2022-01-10 op  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 14 bbcba3ed 2022-01-10 op  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 15 bbcba3ed 2022-01-10 op  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 16 bbcba3ed 2022-01-10 op  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 17 bbcba3ed 2022-01-10 op  */
 18 bbcba3ed 2022-01-10 op 
 19 bbcba3ed 2022-01-10 op #include "compat.h"
 20 bbcba3ed 2022-01-10 op 
 21 bbcba3ed 2022-01-10 op #include <sys/types.h>
 22 bbcba3ed 2022-01-10 op #include <sys/socket.h>
 23 bbcba3ed 2022-01-10 op #include <sys/uio.h>
 24 bbcba3ed 2022-01-10 op 
 25 bbcba3ed 2022-01-10 op #include <limits.h>
 26 bbcba3ed 2022-01-10 op #include <errno.h>
 27 bbcba3ed 2022-01-10 op #include <stdlib.h>
 28 bbcba3ed 2022-01-10 op #include <string.h>
 29 bbcba3ed 2022-01-10 op #include <unistd.h>
 30 bbcba3ed 2022-01-10 op 
 31 bbcba3ed 2022-01-10 op #include "imsg.h"
 32 bbcba3ed 2022-01-10 op 
 33 bbcba3ed 2022-01-10 op static int	ibuf_realloc(struct ibuf *, size_t);
 34 bbcba3ed 2022-01-10 op static void	ibuf_enqueue(struct msgbuf *, struct ibuf *);
 35 bbcba3ed 2022-01-10 op static void	ibuf_dequeue(struct msgbuf *, struct ibuf *);
 36 f229e009 2023-07-02 op static void	msgbuf_drain(struct msgbuf *, size_t);
 37 bbcba3ed 2022-01-10 op 
 38 bbcba3ed 2022-01-10 op struct ibuf *
 39 bbcba3ed 2022-01-10 op ibuf_open(size_t len)
 40 bbcba3ed 2022-01-10 op {
 41 bbcba3ed 2022-01-10 op 	struct ibuf	*buf;
 42 bbcba3ed 2022-01-10 op 
 43 f229e009 2023-07-02 op 	if (len == 0) {
 44 f229e009 2023-07-02 op 		errno = EINVAL;
 45 f229e009 2023-07-02 op 		return (NULL);
 46 f229e009 2023-07-02 op 	}
 47 bbcba3ed 2022-01-10 op 	if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
 48 bbcba3ed 2022-01-10 op 		return (NULL);
 49 f229e009 2023-07-02 op 	if ((buf->buf = calloc(len, 1)) == NULL) {
 50 bbcba3ed 2022-01-10 op 		free(buf);
 51 bbcba3ed 2022-01-10 op 		return (NULL);
 52 bbcba3ed 2022-01-10 op 	}
 53 bbcba3ed 2022-01-10 op 	buf->size = buf->max = len;
 54 bbcba3ed 2022-01-10 op 	buf->fd = -1;
 55 bbcba3ed 2022-01-10 op 
 56 bbcba3ed 2022-01-10 op 	return (buf);
 57 bbcba3ed 2022-01-10 op }
 58 bbcba3ed 2022-01-10 op 
 59 bbcba3ed 2022-01-10 op struct ibuf *
 60 bbcba3ed 2022-01-10 op ibuf_dynamic(size_t len, size_t max)
 61 bbcba3ed 2022-01-10 op {
 62 bbcba3ed 2022-01-10 op 	struct ibuf	*buf;
 63 bbcba3ed 2022-01-10 op 
 64 f229e009 2023-07-02 op 	if (max < len) {
 65 f229e009 2023-07-02 op 		errno = EINVAL;
 66 bbcba3ed 2022-01-10 op 		return (NULL);
 67 f229e009 2023-07-02 op 	}
 68 bbcba3ed 2022-01-10 op 
 69 f229e009 2023-07-02 op 	if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
 70 bbcba3ed 2022-01-10 op 		return (NULL);
 71 f229e009 2023-07-02 op 	if (len > 0) {
 72 f229e009 2023-07-02 op 		if ((buf->buf = calloc(len, 1)) == NULL) {
 73 f229e009 2023-07-02 op 			free(buf);
 74 f229e009 2023-07-02 op 			return (NULL);
 75 f229e009 2023-07-02 op 		}
 76 f229e009 2023-07-02 op 	}
 77 f229e009 2023-07-02 op 	buf->size = len;
 78 f229e009 2023-07-02 op 	buf->max = max;
 79 f229e009 2023-07-02 op 	buf->fd = -1;
 80 bbcba3ed 2022-01-10 op 
 81 bbcba3ed 2022-01-10 op 	return (buf);
 82 bbcba3ed 2022-01-10 op }
 83 bbcba3ed 2022-01-10 op 
 84 bbcba3ed 2022-01-10 op static int
 85 bbcba3ed 2022-01-10 op ibuf_realloc(struct ibuf *buf, size_t len)
 86 bbcba3ed 2022-01-10 op {
 87 bbcba3ed 2022-01-10 op 	unsigned char	*b;
 88 bbcba3ed 2022-01-10 op 
 89 bbcba3ed 2022-01-10 op 	/* on static buffers max is eq size and so the following fails */
 90 f229e009 2023-07-02 op 	if (len > SIZE_MAX - buf->wpos || buf->wpos + len > buf->max) {
 91 bbcba3ed 2022-01-10 op 		errno = ERANGE;
 92 bbcba3ed 2022-01-10 op 		return (-1);
 93 bbcba3ed 2022-01-10 op 	}
 94 bbcba3ed 2022-01-10 op 
 95 bbcba3ed 2022-01-10 op 	b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
 96 bbcba3ed 2022-01-10 op 	if (b == NULL)
 97 bbcba3ed 2022-01-10 op 		return (-1);
 98 bbcba3ed 2022-01-10 op 	buf->buf = b;
 99 bbcba3ed 2022-01-10 op 	buf->size = buf->wpos + len;
100 bbcba3ed 2022-01-10 op 
101 bbcba3ed 2022-01-10 op 	return (0);
102 bbcba3ed 2022-01-10 op }
103 bbcba3ed 2022-01-10 op 
104 bbcba3ed 2022-01-10 op void *
105 bbcba3ed 2022-01-10 op ibuf_reserve(struct ibuf *buf, size_t len)
106 bbcba3ed 2022-01-10 op {
107 bbcba3ed 2022-01-10 op 	void	*b;
108 bbcba3ed 2022-01-10 op 
109 f229e009 2023-07-02 op 	if (len > SIZE_MAX - buf->wpos) {
110 f229e009 2023-07-02 op 		errno = ERANGE;
111 f229e009 2023-07-02 op 		return (NULL);
112 f229e009 2023-07-02 op 	}
113 f229e009 2023-07-02 op 
114 bbcba3ed 2022-01-10 op 	if (buf->wpos + len > buf->size)
115 bbcba3ed 2022-01-10 op 		if (ibuf_realloc(buf, len) == -1)
116 bbcba3ed 2022-01-10 op 			return (NULL);
117 bbcba3ed 2022-01-10 op 
118 bbcba3ed 2022-01-10 op 	b = buf->buf + buf->wpos;
119 bbcba3ed 2022-01-10 op 	buf->wpos += len;
120 f229e009 2023-07-02 op 	memset(b, 0, len);
121 bbcba3ed 2022-01-10 op 	return (b);
122 bbcba3ed 2022-01-10 op }
123 bbcba3ed 2022-01-10 op 
124 f229e009 2023-07-02 op int
125 f229e009 2023-07-02 op ibuf_add(struct ibuf *buf, const void *data, size_t len)
126 f229e009 2023-07-02 op {
127 f229e009 2023-07-02 op 	void *b;
128 f229e009 2023-07-02 op 
129 f229e009 2023-07-02 op 	if ((b = ibuf_reserve(buf, len)) == NULL)
130 f229e009 2023-07-02 op 		return (-1);
131 f229e009 2023-07-02 op 
132 f229e009 2023-07-02 op 	memcpy(b, data, len);
133 f229e009 2023-07-02 op 	return (0);
134 f229e009 2023-07-02 op }
135 f229e009 2023-07-02 op 
136 f229e009 2023-07-02 op int
137 f229e009 2023-07-02 op ibuf_add_buf(struct ibuf *buf, const struct ibuf *from)
138 f229e009 2023-07-02 op {
139 f229e009 2023-07-02 op 	return ibuf_add(buf, from->buf, from->wpos);
140 f229e009 2023-07-02 op }
141 f229e009 2023-07-02 op 
142 f229e009 2023-07-02 op int
143 f229e009 2023-07-02 op ibuf_add_n8(struct ibuf *buf, uint64_t value)
144 f229e009 2023-07-02 op {
145 f229e009 2023-07-02 op 	uint8_t v;
146 f229e009 2023-07-02 op 
147 f229e009 2023-07-02 op 	if (value > UINT8_MAX) {
148 f229e009 2023-07-02 op 		errno = EINVAL;
149 f229e009 2023-07-02 op 		return (-1);
150 f229e009 2023-07-02 op 	}
151 f229e009 2023-07-02 op 	v = value;
152 f229e009 2023-07-02 op 	return ibuf_add(buf, &v, sizeof(v));
153 f229e009 2023-07-02 op }
154 f229e009 2023-07-02 op 
155 f229e009 2023-07-02 op int
156 f229e009 2023-07-02 op ibuf_add_n16(struct ibuf *buf, uint64_t value)
157 f229e009 2023-07-02 op {
158 f229e009 2023-07-02 op 	uint16_t v;
159 f229e009 2023-07-02 op 
160 f229e009 2023-07-02 op 	if (value > UINT16_MAX) {
161 f229e009 2023-07-02 op 		errno = EINVAL;
162 f229e009 2023-07-02 op 		return (-1);
163 f229e009 2023-07-02 op 	}
164 f229e009 2023-07-02 op 	v = htobe16(value);
165 f229e009 2023-07-02 op 	return ibuf_add(buf, &v, sizeof(v));
166 f229e009 2023-07-02 op }
167 f229e009 2023-07-02 op 
168 f229e009 2023-07-02 op int
169 f229e009 2023-07-02 op ibuf_add_n32(struct ibuf *buf, uint64_t value)
170 f229e009 2023-07-02 op {
171 f229e009 2023-07-02 op 	uint32_t v;
172 f229e009 2023-07-02 op 
173 f229e009 2023-07-02 op 	if (value > UINT32_MAX) {
174 f229e009 2023-07-02 op 		errno = EINVAL;
175 f229e009 2023-07-02 op 		return (-1);
176 f229e009 2023-07-02 op 	}
177 f229e009 2023-07-02 op 	v = htobe32(value);
178 f229e009 2023-07-02 op 	return ibuf_add(buf, &v, sizeof(v));
179 f229e009 2023-07-02 op }
180 f229e009 2023-07-02 op 
181 f229e009 2023-07-02 op int
182 f229e009 2023-07-02 op ibuf_add_n64(struct ibuf *buf, uint64_t value)
183 f229e009 2023-07-02 op {
184 f229e009 2023-07-02 op 	value = htobe64(value);
185 f229e009 2023-07-02 op 	return ibuf_add(buf, &value, sizeof(value));
186 f229e009 2023-07-02 op }
187 f229e009 2023-07-02 op 
188 f229e009 2023-07-02 op int
189 f229e009 2023-07-02 op ibuf_add_zero(struct ibuf *buf, size_t len)
190 f229e009 2023-07-02 op {
191 f229e009 2023-07-02 op 	void *b;
192 f229e009 2023-07-02 op 
193 f229e009 2023-07-02 op 	if ((b = ibuf_reserve(buf, len)) == NULL)
194 f229e009 2023-07-02 op 		return (-1);
195 f229e009 2023-07-02 op 	return (0);
196 f229e009 2023-07-02 op }
197 f229e009 2023-07-02 op 
198 bbcba3ed 2022-01-10 op void *
199 bbcba3ed 2022-01-10 op ibuf_seek(struct ibuf *buf, size_t pos, size_t len)
200 bbcba3ed 2022-01-10 op {
201 bbcba3ed 2022-01-10 op 	/* only allowed to seek in already written parts */
202 f229e009 2023-07-02 op 	if (len > SIZE_MAX - pos || pos + len > buf->wpos) {
203 f229e009 2023-07-02 op 		errno = ERANGE;
204 bbcba3ed 2022-01-10 op 		return (NULL);
205 f229e009 2023-07-02 op 	}
206 bbcba3ed 2022-01-10 op 
207 bbcba3ed 2022-01-10 op 	return (buf->buf + pos);
208 bbcba3ed 2022-01-10 op }
209 bbcba3ed 2022-01-10 op 
210 f229e009 2023-07-02 op int
211 f229e009 2023-07-02 op ibuf_set(struct ibuf *buf, size_t pos, const void *data, size_t len)
212 f229e009 2023-07-02 op {
213 f229e009 2023-07-02 op 	void *b;
214 f229e009 2023-07-02 op 
215 f229e009 2023-07-02 op 	if ((b = ibuf_seek(buf, pos, len)) == NULL)
216 f229e009 2023-07-02 op 		return (-1);
217 f229e009 2023-07-02 op 
218 f229e009 2023-07-02 op 	memcpy(b, data, len);
219 f229e009 2023-07-02 op 	return (0);
220 f229e009 2023-07-02 op }
221 f229e009 2023-07-02 op 
222 f229e009 2023-07-02 op int
223 f229e009 2023-07-02 op ibuf_set_n8(struct ibuf *buf, size_t pos, uint64_t value)
224 f229e009 2023-07-02 op {
225 f229e009 2023-07-02 op 	uint8_t v;
226 f229e009 2023-07-02 op 
227 f229e009 2023-07-02 op 	if (value > UINT8_MAX) {
228 f229e009 2023-07-02 op 		errno = EINVAL;
229 f229e009 2023-07-02 op 		return (-1);
230 f229e009 2023-07-02 op 	}
231 f229e009 2023-07-02 op 	v = value;
232 f229e009 2023-07-02 op 	return (ibuf_set(buf, pos, &v, sizeof(v)));
233 f229e009 2023-07-02 op }
234 f229e009 2023-07-02 op 
235 f229e009 2023-07-02 op int
236 f229e009 2023-07-02 op ibuf_set_n16(struct ibuf *buf, size_t pos, uint64_t value)
237 f229e009 2023-07-02 op {
238 f229e009 2023-07-02 op 	uint16_t v;
239 f229e009 2023-07-02 op 
240 f229e009 2023-07-02 op 	if (value > UINT16_MAX) {
241 f229e009 2023-07-02 op 		errno = EINVAL;
242 f229e009 2023-07-02 op 		return (-1);
243 f229e009 2023-07-02 op 	}
244 f229e009 2023-07-02 op 	v = htobe16(value);
245 f229e009 2023-07-02 op 	return (ibuf_set(buf, pos, &v, sizeof(v)));
246 f229e009 2023-07-02 op }
247 f229e009 2023-07-02 op 
248 f229e009 2023-07-02 op int
249 f229e009 2023-07-02 op ibuf_set_n32(struct ibuf *buf, size_t pos, uint64_t value)
250 f229e009 2023-07-02 op {
251 f229e009 2023-07-02 op 	uint32_t v;
252 f229e009 2023-07-02 op 
253 f229e009 2023-07-02 op 	if (value > UINT32_MAX) {
254 f229e009 2023-07-02 op 		errno = EINVAL;
255 f229e009 2023-07-02 op 		return (-1);
256 f229e009 2023-07-02 op 	}
257 f229e009 2023-07-02 op 	v = htobe32(value);
258 f229e009 2023-07-02 op 	return (ibuf_set(buf, pos, &v, sizeof(v)));
259 f229e009 2023-07-02 op }
260 f229e009 2023-07-02 op 
261 f229e009 2023-07-02 op int
262 f229e009 2023-07-02 op ibuf_set_n64(struct ibuf *buf, size_t pos, uint64_t value)
263 f229e009 2023-07-02 op {
264 f229e009 2023-07-02 op 	value = htobe64(value);
265 f229e009 2023-07-02 op 	return (ibuf_set(buf, pos, &value, sizeof(value)));
266 f229e009 2023-07-02 op }
267 f229e009 2023-07-02 op 
268 f229e009 2023-07-02 op void *
269 f229e009 2023-07-02 op ibuf_data(struct ibuf *buf)
270 f229e009 2023-07-02 op {
271 f229e009 2023-07-02 op 	return (buf->buf);
272 f229e009 2023-07-02 op }
273 f229e009 2023-07-02 op 
274 bbcba3ed 2022-01-10 op size_t
275 bbcba3ed 2022-01-10 op ibuf_size(struct ibuf *buf)
276 bbcba3ed 2022-01-10 op {
277 bbcba3ed 2022-01-10 op 	return (buf->wpos);
278 bbcba3ed 2022-01-10 op }
279 bbcba3ed 2022-01-10 op 
280 bbcba3ed 2022-01-10 op size_t
281 bbcba3ed 2022-01-10 op ibuf_left(struct ibuf *buf)
282 bbcba3ed 2022-01-10 op {
283 bbcba3ed 2022-01-10 op 	return (buf->max - buf->wpos);
284 bbcba3ed 2022-01-10 op }
285 bbcba3ed 2022-01-10 op 
286 bbcba3ed 2022-01-10 op void
287 bbcba3ed 2022-01-10 op ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
288 bbcba3ed 2022-01-10 op {
289 bbcba3ed 2022-01-10 op 	ibuf_enqueue(msgbuf, buf);
290 bbcba3ed 2022-01-10 op }
291 bbcba3ed 2022-01-10 op 
292 f229e009 2023-07-02 op void
293 f229e009 2023-07-02 op ibuf_free(struct ibuf *buf)
294 f229e009 2023-07-02 op {
295 f229e009 2023-07-02 op 	if (buf == NULL)
296 f229e009 2023-07-02 op 		return;
297 f229e009 2023-07-02 op #ifdef NOTYET
298 f229e009 2023-07-02 op 	if (buf->fd != -1)
299 f229e009 2023-07-02 op 		close(buf->fd);
300 f229e009 2023-07-02 op #endif
301 f229e009 2023-07-02 op 	freezero(buf->buf, buf->size);
302 f229e009 2023-07-02 op 	free(buf);
303 f229e009 2023-07-02 op }
304 f229e009 2023-07-02 op 
305 bbcba3ed 2022-01-10 op int
306 f229e009 2023-07-02 op ibuf_fd_avail(struct ibuf *buf)
307 f229e009 2023-07-02 op {
308 f229e009 2023-07-02 op 	return (buf->fd != -1);
309 f229e009 2023-07-02 op }
310 f229e009 2023-07-02 op 
311 f229e009 2023-07-02 op int
312 f229e009 2023-07-02 op ibuf_fd_get(struct ibuf *buf)
313 f229e009 2023-07-02 op {
314 f229e009 2023-07-02 op 	int fd;
315 f229e009 2023-07-02 op 
316 f229e009 2023-07-02 op 	fd = buf->fd;
317 f229e009 2023-07-02 op #ifdef NOTYET
318 f229e009 2023-07-02 op 	buf->fd = -1;
319 f229e009 2023-07-02 op #endif
320 f229e009 2023-07-02 op 	return (fd);
321 f229e009 2023-07-02 op }
322 f229e009 2023-07-02 op 
323 f229e009 2023-07-02 op void
324 f229e009 2023-07-02 op ibuf_fd_set(struct ibuf *buf, int fd)
325 f229e009 2023-07-02 op {
326 f229e009 2023-07-02 op 	if (buf->fd != -1)
327 f229e009 2023-07-02 op 		close(buf->fd);
328 f229e009 2023-07-02 op 	buf->fd = fd;
329 f229e009 2023-07-02 op }
330 f229e009 2023-07-02 op 
331 f229e009 2023-07-02 op int
332 bbcba3ed 2022-01-10 op ibuf_write(struct msgbuf *msgbuf)
333 bbcba3ed 2022-01-10 op {
334 bbcba3ed 2022-01-10 op 	struct iovec	 iov[IOV_MAX];
335 bbcba3ed 2022-01-10 op 	struct ibuf	*buf;
336 bbcba3ed 2022-01-10 op 	unsigned int	 i = 0;
337 bbcba3ed 2022-01-10 op 	ssize_t	n;
338 bbcba3ed 2022-01-10 op 
339 bbcba3ed 2022-01-10 op 	memset(&iov, 0, sizeof(iov));
340 bbcba3ed 2022-01-10 op 	TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
341 bbcba3ed 2022-01-10 op 		if (i >= IOV_MAX)
342 bbcba3ed 2022-01-10 op 			break;
343 bbcba3ed 2022-01-10 op 		iov[i].iov_base = buf->buf + buf->rpos;
344 bbcba3ed 2022-01-10 op 		iov[i].iov_len = buf->wpos - buf->rpos;
345 bbcba3ed 2022-01-10 op 		i++;
346 bbcba3ed 2022-01-10 op 	}
347 bbcba3ed 2022-01-10 op 
348 bbcba3ed 2022-01-10 op again:
349 bbcba3ed 2022-01-10 op 	if ((n = writev(msgbuf->fd, iov, i)) == -1) {
350 bbcba3ed 2022-01-10 op 		if (errno == EINTR)
351 bbcba3ed 2022-01-10 op 			goto again;
352 bbcba3ed 2022-01-10 op 		if (errno == ENOBUFS)
353 bbcba3ed 2022-01-10 op 			errno = EAGAIN;
354 bbcba3ed 2022-01-10 op 		return (-1);
355 bbcba3ed 2022-01-10 op 	}
356 bbcba3ed 2022-01-10 op 
357 bbcba3ed 2022-01-10 op 	if (n == 0) {			/* connection closed */
358 bbcba3ed 2022-01-10 op 		errno = 0;
359 bbcba3ed 2022-01-10 op 		return (0);
360 bbcba3ed 2022-01-10 op 	}
361 bbcba3ed 2022-01-10 op 
362 bbcba3ed 2022-01-10 op 	msgbuf_drain(msgbuf, n);
363 bbcba3ed 2022-01-10 op 
364 bbcba3ed 2022-01-10 op 	return (1);
365 bbcba3ed 2022-01-10 op }
366 bbcba3ed 2022-01-10 op 
367 bbcba3ed 2022-01-10 op void
368 bbcba3ed 2022-01-10 op msgbuf_init(struct msgbuf *msgbuf)
369 bbcba3ed 2022-01-10 op {
370 bbcba3ed 2022-01-10 op 	msgbuf->queued = 0;
371 bbcba3ed 2022-01-10 op 	msgbuf->fd = -1;
372 bbcba3ed 2022-01-10 op 	TAILQ_INIT(&msgbuf->bufs);
373 bbcba3ed 2022-01-10 op }
374 bbcba3ed 2022-01-10 op 
375 f229e009 2023-07-02 op static void
376 bbcba3ed 2022-01-10 op msgbuf_drain(struct msgbuf *msgbuf, size_t n)
377 bbcba3ed 2022-01-10 op {
378 bbcba3ed 2022-01-10 op 	struct ibuf	*buf, *next;
379 bbcba3ed 2022-01-10 op 
380 bbcba3ed 2022-01-10 op 	for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
381 bbcba3ed 2022-01-10 op 	    buf = next) {
382 bbcba3ed 2022-01-10 op 		next = TAILQ_NEXT(buf, entry);
383 f229e009 2023-07-02 op 		if (n >= buf->wpos - buf->rpos) {
384 bbcba3ed 2022-01-10 op 			n -= buf->wpos - buf->rpos;
385 bbcba3ed 2022-01-10 op 			ibuf_dequeue(msgbuf, buf);
386 bbcba3ed 2022-01-10 op 		} else {
387 bbcba3ed 2022-01-10 op 			buf->rpos += n;
388 bbcba3ed 2022-01-10 op 			n = 0;
389 bbcba3ed 2022-01-10 op 		}
390 bbcba3ed 2022-01-10 op 	}
391 bbcba3ed 2022-01-10 op }
392 bbcba3ed 2022-01-10 op 
393 bbcba3ed 2022-01-10 op void
394 bbcba3ed 2022-01-10 op msgbuf_clear(struct msgbuf *msgbuf)
395 bbcba3ed 2022-01-10 op {
396 bbcba3ed 2022-01-10 op 	struct ibuf	*buf;
397 bbcba3ed 2022-01-10 op 
398 bbcba3ed 2022-01-10 op 	while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
399 bbcba3ed 2022-01-10 op 		ibuf_dequeue(msgbuf, buf);
400 bbcba3ed 2022-01-10 op }
401 bbcba3ed 2022-01-10 op 
402 bbcba3ed 2022-01-10 op int
403 bbcba3ed 2022-01-10 op msgbuf_write(struct msgbuf *msgbuf)
404 bbcba3ed 2022-01-10 op {
405 bbcba3ed 2022-01-10 op 	struct iovec	 iov[IOV_MAX];
406 f229e009 2023-07-02 op 	struct ibuf	*buf, *buf0 = NULL;
407 bbcba3ed 2022-01-10 op 	unsigned int	 i = 0;
408 bbcba3ed 2022-01-10 op 	ssize_t		 n;
409 bbcba3ed 2022-01-10 op 	struct msghdr	 msg;
410 bbcba3ed 2022-01-10 op 	struct cmsghdr	*cmsg;
411 bbcba3ed 2022-01-10 op 	union {
412 bbcba3ed 2022-01-10 op 		struct cmsghdr	hdr;
413 bbcba3ed 2022-01-10 op 		char		buf[CMSG_SPACE(sizeof(int))];
414 bbcba3ed 2022-01-10 op 	} cmsgbuf;
415 bbcba3ed 2022-01-10 op 
416 bbcba3ed 2022-01-10 op 	memset(&iov, 0, sizeof(iov));
417 bbcba3ed 2022-01-10 op 	memset(&msg, 0, sizeof(msg));
418 bbcba3ed 2022-01-10 op 	memset(&cmsgbuf, 0, sizeof(cmsgbuf));
419 bbcba3ed 2022-01-10 op 	TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
420 bbcba3ed 2022-01-10 op 		if (i >= IOV_MAX)
421 bbcba3ed 2022-01-10 op 			break;
422 f229e009 2023-07-02 op 		if (i > 0 && buf->fd != -1)
423 f229e009 2023-07-02 op 			break;
424 bbcba3ed 2022-01-10 op 		iov[i].iov_base = buf->buf + buf->rpos;
425 bbcba3ed 2022-01-10 op 		iov[i].iov_len = buf->wpos - buf->rpos;
426 bbcba3ed 2022-01-10 op 		i++;
427 bbcba3ed 2022-01-10 op 		if (buf->fd != -1)
428 f229e009 2023-07-02 op 			buf0 = buf;
429 bbcba3ed 2022-01-10 op 	}
430 bbcba3ed 2022-01-10 op 
431 bbcba3ed 2022-01-10 op 	msg.msg_iov = iov;
432 bbcba3ed 2022-01-10 op 	msg.msg_iovlen = i;
433 bbcba3ed 2022-01-10 op 
434 f229e009 2023-07-02 op 	if (buf0 != NULL) {
435 bbcba3ed 2022-01-10 op 		msg.msg_control = (caddr_t)&cmsgbuf.buf;
436 bbcba3ed 2022-01-10 op 		msg.msg_controllen = sizeof(cmsgbuf.buf);
437 bbcba3ed 2022-01-10 op 		cmsg = CMSG_FIRSTHDR(&msg);
438 bbcba3ed 2022-01-10 op 		cmsg->cmsg_len = CMSG_LEN(sizeof(int));
439 bbcba3ed 2022-01-10 op 		cmsg->cmsg_level = SOL_SOCKET;
440 bbcba3ed 2022-01-10 op 		cmsg->cmsg_type = SCM_RIGHTS;
441 f229e009 2023-07-02 op 		*(int *)CMSG_DATA(cmsg) = buf0->fd;
442 bbcba3ed 2022-01-10 op 	}
443 bbcba3ed 2022-01-10 op 
444 bbcba3ed 2022-01-10 op again:
445 bbcba3ed 2022-01-10 op 	if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
446 bbcba3ed 2022-01-10 op 		if (errno == EINTR)
447 bbcba3ed 2022-01-10 op 			goto again;
448 bbcba3ed 2022-01-10 op 		if (errno == ENOBUFS)
449 bbcba3ed 2022-01-10 op 			errno = EAGAIN;
450 bbcba3ed 2022-01-10 op 		return (-1);
451 bbcba3ed 2022-01-10 op 	}
452 bbcba3ed 2022-01-10 op 
453 bbcba3ed 2022-01-10 op 	if (n == 0) {			/* connection closed */
454 bbcba3ed 2022-01-10 op 		errno = 0;
455 bbcba3ed 2022-01-10 op 		return (0);
456 bbcba3ed 2022-01-10 op 	}
457 bbcba3ed 2022-01-10 op 
458 bbcba3ed 2022-01-10 op 	/*
459 bbcba3ed 2022-01-10 op 	 * assumption: fd got sent if sendmsg sent anything
460 bbcba3ed 2022-01-10 op 	 * this works because fds are passed one at a time
461 bbcba3ed 2022-01-10 op 	 */
462 f229e009 2023-07-02 op 	if (buf0 != NULL) {
463 f229e009 2023-07-02 op 		close(buf0->fd);
464 f229e009 2023-07-02 op 		buf0->fd = -1;
465 bbcba3ed 2022-01-10 op 	}
466 bbcba3ed 2022-01-10 op 
467 bbcba3ed 2022-01-10 op 	msgbuf_drain(msgbuf, n);
468 bbcba3ed 2022-01-10 op 
469 bbcba3ed 2022-01-10 op 	return (1);
470 bbcba3ed 2022-01-10 op }
471 bbcba3ed 2022-01-10 op 
472 bbcba3ed 2022-01-10 op static void
473 bbcba3ed 2022-01-10 op ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
474 bbcba3ed 2022-01-10 op {
475 bbcba3ed 2022-01-10 op 	TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
476 bbcba3ed 2022-01-10 op 	msgbuf->queued++;
477 bbcba3ed 2022-01-10 op }
478 bbcba3ed 2022-01-10 op 
479 bbcba3ed 2022-01-10 op static void
480 bbcba3ed 2022-01-10 op ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
481 bbcba3ed 2022-01-10 op {
482 bbcba3ed 2022-01-10 op 	TAILQ_REMOVE(&msgbuf->bufs, buf, entry);
483 bbcba3ed 2022-01-10 op 
484 f229e009 2023-07-02 op 	if (buf->fd != -1) {
485 bbcba3ed 2022-01-10 op 		close(buf->fd);
486 f229e009 2023-07-02 op 		buf->fd = -1;
487 f229e009 2023-07-02 op 	}
488 bbcba3ed 2022-01-10 op 
489 bbcba3ed 2022-01-10 op 	msgbuf->queued--;
490 bbcba3ed 2022-01-10 op 	ibuf_free(buf);
491 bbcba3ed 2022-01-10 op }