[dragonfly.git] / sbin / dhclient / privsep.c

/*	$OpenBSD: src/sbin/dhclient/privsep.c,v 1.16 2011/04/04 11:14:52 krw Exp $	*/

/*
 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE, ABUSE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "dhcpd.h"
#include "privsep.h"

struct buf *
buf_open(size_t len)
{
	struct buf	*buf;

	if ((buf = calloc(1, sizeof(struct buf))) == NULL)
		error("buf_open: %m");
	if ((buf->buf = malloc(len)) == NULL) {
		free(buf);
		error("buf_open: %m");
	}
	buf->size = len;

	return (buf);
}

void
buf_add(struct buf *buf, void *data, size_t len)
{
	if (len == 0)
		return;

	if (buf->wpos + len > buf->size)
		error("buf_add: %m");

	memcpy(buf->buf + buf->wpos, data, len);
	buf->wpos += len;
}

void
buf_close(int sock, struct buf *buf)
{
	ssize_t	n;

	do {
		n = write(sock, buf->buf + buf->rpos, buf->size - buf->rpos);
		if (n == 0)			/* connection closed */
			error("buf_close (connection closed)");
		if (n != -1 && n < buf->size - buf->rpos)
			error("buf_close (short write): %m");

	} while (n == -1 && (errno == EAGAIN || errno == EINTR));

	if (n == -1)
		error("buf_close: %m");

	free(buf->buf);
	free(buf);
}

void
buf_read(int sock, void *buf, size_t nbytes)
{
	ssize_t	n;

	do {
		n = read(sock, buf, nbytes);
		if (n == 0) {			/* connection closed */
#ifdef DEBUG
			debug("buf_read (connection closed)");
#endif
			exit(1);
		}
		if (n != -1 && n < nbytes)
			error("buf_read (short read): %m");
	} while (n == -1 && (errno == EINTR || errno == EAGAIN));

	if (n == -1)
		error("buf_read: %m");
}

void
dispatch_imsg(int fd)
{
	struct imsg_hdr		 hdr;
	char			*reason, *filename,
				*servername, *prefix;
	size_t			 reason_len, filename_len,
				 servername_len, prefix_len, totlen;
	struct client_lease	 lease;
	int			 ret, i, optlen;
	struct buf		*buf;

	buf_read(fd, &hdr, sizeof(hdr));

	switch (hdr.code) {
	case IMSG_SCRIPT_INIT:
		if (hdr.len < sizeof(hdr) + sizeof(size_t))
			error("corrupted message received");
		buf_read(fd, &reason_len, sizeof(reason_len));
		if (hdr.len < reason_len + sizeof(hdr) + sizeof(size_t) ||
		    reason_len == SIZE_T_MAX)
			error("corrupted message received");
		if (reason_len > 0) {
			if ((reason = calloc(1, reason_len + 1)) == NULL)
				error("%m");
			buf_read(fd, reason, reason_len);
		} else
			reason = NULL;

		priv_script_init(reason);
		free(reason);
		break;
	case IMSG_SCRIPT_WRITE_PARAMS:
		bzero(&lease, sizeof lease);
		totlen = sizeof(hdr) + sizeof(lease) + sizeof(size_t);
		if (hdr.len < totlen)
			error("corrupted message received");
		buf_read(fd, &lease, sizeof(lease));

		buf_read(fd, &filename_len, sizeof(filename_len));
		totlen += filename_len + sizeof(size_t);
		if (hdr.len < totlen || filename_len == SIZE_T_MAX)
			error("corrupted message received");
		if (filename_len > 0) {
			if ((filename = calloc(1, filename_len + 1)) == NULL)
				error("%m");
			buf_read(fd, filename, filename_len);
		} else
			filename = NULL;

		buf_read(fd, &servername_len, sizeof(servername_len));
		totlen += servername_len + sizeof(size_t);
		if (hdr.len < totlen || servername_len == SIZE_T_MAX)
			error("corrupted message received");
		if (servername_len > 0) {
			if ((servername =
			    calloc(1, servername_len + 1)) == NULL)
				error("%m");
			buf_read(fd, servername, servername_len);
		} else
			servername = NULL;

		buf_read(fd, &prefix_len, sizeof(prefix_len));
		totlen += prefix_len;
		if (hdr.len < totlen || prefix_len == SIZE_T_MAX)
			error("corrupted message received");
		if (prefix_len > 0) {
			if ((prefix = calloc(1, prefix_len + 1)) == NULL)
				error("%m");
			buf_read(fd, prefix, prefix_len);
		} else
			prefix = NULL;

		for (i = 0; i < 256; i++) {
			totlen += sizeof(optlen);
			if (hdr.len < totlen)
				error("corrupted message received");
			buf_read(fd, &optlen, sizeof(optlen));
			lease.options[i].data = NULL;
			lease.options[i].len = optlen;
			if (optlen > 0) {
				totlen += optlen;
				if (hdr.len < totlen || optlen == SIZE_T_MAX)
					error("corrupted message received");
				lease.options[i].data =
				    calloc(1, optlen + 1);
				if (lease.options[i].data == NULL)
				    error("%m");
				buf_read(fd, lease.options[i].data, optlen);
			}
		}
		lease.server_name = servername;
		lease.filename = filename;

		priv_script_write_params(prefix, &lease);

		free(servername);
		free(filename);
		free(prefix);
		for (i = 0; i < 256; i++)
			if (lease.options[i].len > 0)
				free(lease.options[i].data);
		break;
	case IMSG_SCRIPT_GO:
		if (hdr.len != sizeof(hdr))
			error("corrupted message received");

		ret = priv_script_go();

		hdr.code = IMSG_SCRIPT_GO_RET;
		hdr.len = sizeof(struct imsg_hdr) + sizeof(int);
		if ((buf = buf_open(hdr.len)) == NULL)
			error("buf_open: %m");
		buf_add(buf, &hdr, sizeof(hdr));
		buf_add(buf, &ret, sizeof(ret));
		buf_close(fd, buf);
		break;
	default:
		error("received unknown message, code %d", hdr.code);
	}
}
Commit	Line	Data
f155048f	1	/* $OpenBSD: src/sbin/dhclient/privsep.c,v 1.16 2011/04/04 11:14:52 krw Exp $ */
846204b6 HT	2
	3	/*
	4	* Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
	5	*
	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.
	9	*
	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 MIND, USE, DATA OR PROFITS, WHETHER IN
	15	* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
	16	* OF OR IN CONNECTION WITH THE USE, ABUSE OR PERFORMANCE OF THIS SOFTWARE.
	17	*/
	18
	19	#include "dhcpd.h"
	20	#include "privsep.h"
	21
	22	struct buf *
	23	buf_open(size_t len)
	24	{
	25	struct buf *buf;
	26
	27	if ((buf = calloc(1, sizeof(struct buf))) == NULL)
	28	error("buf_open: %m");
	29	if ((buf->buf = malloc(len)) == NULL) {
	30	free(buf);
	31	error("buf_open: %m");
	32	}
	33	buf->size = len;
	34
	35	return (buf);
	36	}
	37
	38	void
	39	buf_add(struct buf buf, void data, size_t len)
	40	{
	41	if (len == 0)
	42	return;
	43
	44	if (buf->wpos + len > buf->size)
	45	error("buf_add: %m");
	46
	47	memcpy(buf->buf + buf->wpos, data, len);
	48	buf->wpos += len;
	49	}
	50
	51	void
	52	buf_close(int sock, struct buf *buf)
	53	{
	54	ssize_t n;
	55
	56	do {
	57	n = write(sock, buf->buf + buf->rpos, buf->size - buf->rpos);
	58	if (n == 0) /* connection closed */
	59	error("buf_close (connection closed)");
	60	if (n != -1 && n < buf->size - buf->rpos)
	61	error("buf_close (short write): %m");
	62
	63	} while (n == -1 && (errno == EAGAIN \|\| errno == EINTR));
	64
	65	if (n == -1)
66	error("buf_close: %m");
67
68	free(buf->buf);
69	free(buf);
70	}
71
72	void
73	buf_read(int sock, void *buf, size_t nbytes)
74	{
75	ssize_t n;
76
77	do {
78	n = read(sock, buf, nbytes);
79	if (n == 0) { /* connection closed */
84c21dc9	80	#ifdef DEBUG
846204b6	81	debug("buf_read (connection closed)");
84c21dc9	82	#endif
846204b6 HT	83	exit(1);
	84	}
	85	if (n != -1 && n < nbytes)
	86	error("buf_read (short read): %m");
	87	} while (n == -1 && (errno == EINTR \|\| errno == EAGAIN));
	88
	89	if (n == -1)
	90	error("buf_read: %m");
	91	}
	92
	93	void
	94	dispatch_imsg(int fd)
	95	{
	96	struct imsg_hdr hdr;
f155048f	97	char reason, filename,
846204b6	98	servername, prefix;
f155048f	99	size_t reason_len, filename_len,
846204b6 HT	100	servername_len, prefix_len, totlen;
	101	struct client_lease lease;
	102	int ret, i, optlen;
	103	struct buf *buf;
	104
	105	buf_read(fd, &hdr, sizeof(hdr));
	106
	107	switch (hdr.code) {
	108	case IMSG_SCRIPT_INIT:
	109	if (hdr.len < sizeof(hdr) + sizeof(size_t))
	110	error("corrupted message received");
846204b6	111	buf_read(fd, &reason_len, sizeof(reason_len));
f155048f	112	if (hdr.len < reason_len + sizeof(hdr) + sizeof(size_t) \|\|
846204b6 HT	113	reason_len == SIZE_T_MAX)
	114	error("corrupted message received");
	115	if (reason_len > 0) {
	116	if ((reason = calloc(1, reason_len + 1)) == NULL)
	117	error("%m");
	118	buf_read(fd, reason, reason_len);
	119	} else
	120	reason = NULL;
	121
f155048f	122	priv_script_init(reason);
846204b6	123	free(reason);
846204b6 HT	124	break;
	125	case IMSG_SCRIPT_WRITE_PARAMS:
	126	bzero(&lease, sizeof lease);
	127	totlen = sizeof(hdr) + sizeof(lease) + sizeof(size_t);
	128	if (hdr.len < totlen)
	129	error("corrupted message received");
	130	buf_read(fd, &lease, sizeof(lease));
	131
	132	buf_read(fd, &filename_len, sizeof(filename_len));
	133	totlen += filename_len + sizeof(size_t);
	134	if (hdr.len < totlen \|\| filename_len == SIZE_T_MAX)
	135	error("corrupted message received");
	136	if (filename_len > 0) {
	137	if ((filename = calloc(1, filename_len + 1)) == NULL)
	138	error("%m");
	139	buf_read(fd, filename, filename_len);
	140	} else
	141	filename = NULL;
	142
	143	buf_read(fd, &servername_len, sizeof(servername_len));
	144	totlen += servername_len + sizeof(size_t);
	145	if (hdr.len < totlen \|\| servername_len == SIZE_T_MAX)
	146	error("corrupted message received");
	147	if (servername_len > 0) {
	148	if ((servername =
	149	calloc(1, servername_len + 1)) == NULL)
	150	error("%m");
	151	buf_read(fd, servername, servername_len);
	152	} else
	153	servername = NULL;
	154
	155	buf_read(fd, &prefix_len, sizeof(prefix_len));
	156	totlen += prefix_len;
	157	if (hdr.len < totlen \|\| prefix_len == SIZE_T_MAX)
	158	error("corrupted message received");
	159	if (prefix_len > 0) {
	160	if ((prefix = calloc(1, prefix_len + 1)) == NULL)
	161	error("%m");
	162	buf_read(fd, prefix, prefix_len);
	163	} else
	164	prefix = NULL;
	165
	166	for (i = 0; i < 256; i++) {
	167	totlen += sizeof(optlen);
	168	if (hdr.len < totlen)
	169	error("corrupted message received");
	170	buf_read(fd, &optlen, sizeof(optlen));
	171	lease.options[i].data = NULL;
	172	lease.options[i].len = optlen;
	173	if (optlen > 0) {
	174	totlen += optlen;
	175	if (hdr.len < totlen \|\| optlen == SIZE_T_MAX)
	176	error("corrupted message received");
	177	lease.options[i].data =
	178	calloc(1, optlen + 1);
	179	if (lease.options[i].data == NULL)
	180	error("%m");
	181	buf_read(fd, lease.options[i].data, optlen);
	182	}
	183	}
	184	lease.server_name = servername;
	185	lease.filename = filename;
	186
	187	priv_script_write_params(prefix, &lease);
188
189	free(servername);
190	free(filename);
191	free(prefix);
192	for (i = 0; i < 256; i++)
193	if (lease.options[i].len > 0)
194	free(lease.options[i].data);
195	break;
196	case IMSG_SCRIPT_GO:
197	if (hdr.len != sizeof(hdr))
198	error("corrupted message received");
199
200	ret = priv_script_go();
201
202	hdr.code = IMSG_SCRIPT_GO_RET;
203	hdr.len = sizeof(struct imsg_hdr) + sizeof(int);
204	if ((buf = buf_open(hdr.len)) == NULL)
205	error("buf_open: %m");
206	buf_add(buf, &hdr, sizeof(hdr));
207	buf_add(buf, &ret, sizeof(ret));
208	buf_close(fd, buf);
209	break;
210	default:
211	error("received unknown message, code %d", hdr.code);
212	}
213	}