summaryrefslogtreecommitdiff
path: root/udev_utils_run.c
blob: cf633661e4b1e29ce20433bc446f408be797cd8c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
/*
 * udev_utils_run.c - execute programs from udev and read its output
 *
 * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License as published by the
 *	Free Software Foundation version 2 of the License.
 * 
 *	This program is distributed in the hope that it will be useful, but
 *	WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *	General Public License for more details.
 * 
 *	You should have received a copy of the GNU General Public License along
 *	with this program; if not, write to the Free Software Foundation, Inc.,
 *	675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */


#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/select.h>

#include "udev_libc_wrapper.h"
#include "udev.h"
#include "logging.h"
#include "udev_utils.h"
#include "list.h"


int pass_env_to_socket(const char *sockname, const char *devpath, const char *action)
{
	int sock;
	struct sockaddr_un saddr;
	socklen_t addrlen;
	char buf[2048];
	size_t bufpos = 0;
	int i;
	int retval;

	dbg("pass environment to socket '%s'", sockname);
	sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
	memset(&saddr, 0x00, sizeof(struct sockaddr_un));
	saddr.sun_family = AF_LOCAL;
	/* only abstract namespace is supported */
	strcpy(&saddr.sun_path[1], sockname);
	addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;

	bufpos = snprintf(buf, sizeof(buf)-1, "%s@%s", action, devpath);
	bufpos++;
	for (i = 0; environ[i] != NULL && bufpos < sizeof(buf); i++) {
		bufpos += strlcpy(&buf[bufpos], environ[i], sizeof(buf) - bufpos-1);
		bufpos++;
	}

	retval = sendto(sock, &buf, bufpos, 0, (struct sockaddr *)&saddr, addrlen);
	if (retval != -1)
		retval = 0;

	close(sock);
	return retval;
}

int run_program(const char *command, const char *subsystem,
		char *result, size_t ressize, size_t *reslen, int dbg)
{
	int retval = 0;
	int status;
	int outpipe[2] = {-1, -1};
	int errpipe[2] = {-1, -1};
	pid_t pid;
	char *pos;
	char arg[PATH_SIZE];
	char *argv[(sizeof(arg) / 2) + 1];
	int devnull;
	int i;

	strlcpy(arg, command, sizeof(arg));
	i = 0;
	if (strchr(arg, ' ')) {
		pos = arg;
		while (pos != NULL) {
			if (pos[0] == '\'') {
				/* don't separate if in apostrophes */
				pos++;
				argv[i] = strsep(&pos, "\'");
				while (pos && pos[0] == ' ')
					pos++;
			} else {
				argv[i] = strsep(&pos, " ");
			}
			dbg("arg[%i] '%s'", i, argv[i]);
			i++;
		}
		argv[i] = NULL;
		dbg("execute '%s' with parsed arguments", arg);
	} else {
		argv[0] = arg;
		argv[1] = (char *) subsystem;
		argv[2] = NULL;
		dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
	}

	/* prepare pipes from child to parent */
	if (result || dbg) {
		if (pipe(outpipe) != 0) {
			err("pipe failed");
			return -1;
		}
	}
	if (dbg) {
		if (pipe(errpipe) != 0) {
			err("pipe failed");
			return -1;
		}
	}

	pid = fork();
	switch(pid) {
	case 0:
		/* child closes parent ends of pipes */
		if (outpipe[0] > 0)
			close(outpipe[0]);
		if (errpipe[0] > 0)
			close(errpipe[0]);

		/* discard child output or connect to pipe */
		devnull = open("/dev/null", O_RDWR);
		if (devnull > 0) {
			dup2(devnull, STDIN_FILENO);
			if (outpipe[1] < 0)
				dup2(devnull, STDOUT_FILENO);
			if (errpipe[1] < 0)
				dup2(devnull, STDERR_FILENO);
			close(devnull);
		} else
			err("open /dev/null failed");
		if (outpipe[1] > 0)
			dup2(outpipe[1], STDOUT_FILENO);
		if (errpipe[1] > 0)
			dup2(errpipe[1], STDERR_FILENO);
		execv(arg, argv);

		/* we should never reach this */
		err("exec of program failed");
		_exit(1);
	case -1:
		err("fork of '%s' failed", arg);
		return -1;
	default:
		/* read from child if requested */
		if (outpipe[0] > 0 || errpipe[0] > 0) {
			ssize_t count;
			size_t respos = 0;

			/* parent closes child ends of pipes */
			if (outpipe[1] > 0)
				close(outpipe[1]);
			if (errpipe[1] > 0)
				close(errpipe[1]);

			/* read child output */
			while (outpipe[0] > 0 || errpipe[0] > 0) {
				int fdcount;
				fd_set readfds;

				FD_ZERO(&readfds);
				if (outpipe[0] > 0)
					FD_SET(outpipe[0], &readfds);
				if (errpipe[0] > 0)
					FD_SET(errpipe[0], &readfds);
				fdcount = select(UDEV_MAX(outpipe[0], errpipe[0])+1, &readfds, NULL, NULL, NULL);
				if (fdcount < 0) {
					if (errno == EINTR)
						continue;
					retval = -1;
					break;
				}

				/* get stdout */
				if (outpipe[0] > 0 && FD_ISSET(outpipe[0], &readfds)) {
					char inbuf[1024];

					count = read(outpipe[0], inbuf, sizeof(inbuf)-1);
					if (count <= 0) {
						close(outpipe[0]);
						outpipe[0] = -1;
						if (count < 0) {
							err("stdin read failed with '%s'", strerror(errno));
							retval = -1;
						}
						continue;
					}
					inbuf[count] = '\0';
					dbg("stdout: '%s'", inbuf);

					if (result) {
						if (respos + count >= ressize) {
							err("ressize %ld too short", (long)ressize);
							retval = -1;
							continue;
						}
						memcpy(&result[respos], inbuf, count);
						respos += count;
					}
				}

				/* get stderr */
				if (errpipe[0] > 0 && FD_ISSET(errpipe[0], &readfds)) {
					char errbuf[1024];

					count = read(errpipe[0], errbuf, sizeof(errbuf)-1);
					if (count <= 0) {
						close(errpipe[0]);
						errpipe[0] = -1;
						if (count < 0)
							err("stderr read failed with '%s'", strerror(errno));
						continue;
					}
					errbuf[count] = '\0';
					dbg("stderr: '%s'", errbuf);
				}
			}
			if (outpipe[0] > 0)
				close(outpipe[0]);
			if (errpipe[0] > 0)
				close(errpipe[0]);

			/* return the childs stdout string */
			if (result) {
				result[respos] = '\0';
				dbg("result='%s'", result);
				if (reslen)
					*reslen = respos;
			}
		}
		waitpid(pid, &status, 0);
		if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
			dbg("exec program status 0x%x", status);
			retval = -1;
		}
	}

	return retval;
}