1 /***
2 This file is part of libdaemon.
3
4 Copyright 2003-2008 Lennart Poettering
5
6 Permission is hereby granted, free of charge, to any person obtaining a copy
7 of this software and associated documentation files (the "Software"), to deal
8 in the Software without restriction, including without limitation the rights
9 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 copies of the Software, and to permit persons to whom the Software is
11 furnished to do so, subject to the following conditions:
12
13 The above copyright notice and this permission notice shall be included in
14 all copies or substantial portions of the Software.
15
16 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 SOFTWARE.
23
24 ***/
25
26 #ifdef HAVE_CONFIG_H
27 #include <config.h>
28 #endif
29
30 #include <sys/types.h>
31 #include <unistd.h>
32 #include <string.h>
33 #include <errno.h>
34 #include <sys/stat.h>
35 #include <stdlib.h>
36 #include <signal.h>
37 #include <sys/wait.h>
38 #include <limits.h>
39 #include <fcntl.h>
40 #include <stdio.h>
41 #include <stdarg.h>
42 #include <assert.h>
43
44 #include "dlog.h"
45 #include "dsignal.h"
46 #include "dfork.h"
47 #include "dexec.h"
48
49 #define MAX_ARGS 64
50
daemon_execv(const char * dir,int * ret,const char * prog,va_list ap)51 int daemon_execv(const char *dir, int *ret, const char *prog, va_list ap) {
52 pid_t pid;
53 int p[2];
54 unsigned n = 0;
55 static char buf[256];
56 int sigfd, r;
57 fd_set fds;
58 int saved_errno;
59
60 assert(daemon_signal_fd() >= 0);
61
62 if (pipe(p) < 0) {
63 daemon_log(LOG_ERR, "pipe() failed: %s", strerror(errno));
64 return -1;
65 }
66
67 if ((pid = fork()) < 0) {
68 daemon_log(LOG_ERR, "fork() failed: %s", strerror(errno));
69
70 saved_errno = errno;
71 close(p[0]);
72 close(p[1]);
73 errno = saved_errno;
74
75 return -1;
76
77 } else if (pid == 0) {
78 char *args[MAX_ARGS];
79 int i;
80
81 if (p[1] != 1)
82 if (dup2(p[1], 1) < 0) {
83 daemon_log(LOG_ERR, "dup2: %s", strerror(errno));
84 goto fail;
85 }
86
87 if (p[1] != 2)
88 if (dup2(p[1], 2) < 0) {
89 daemon_log(LOG_ERR, "dup2: %s", strerror(errno));
90 goto fail;
91 }
92
93
94 if (p[0] > 2)
95 close(p[0]);
96
97 if (p[1] > 2)
98 close(p[1]);
99
100 close(0);
101
102 if (open("/dev/null", O_RDONLY) != 0) {
103 daemon_log(LOG_ERR, "Unable to open /dev/null as STDIN");
104 goto fail;
105 }
106
107 daemon_close_all(-1);
108 daemon_reset_sigs(-1);
109 daemon_unblock_sigs(-1);
110
111 umask(0022); /* Set up a sane umask */
112
113 if (dir && chdir(dir) < 0) {
114 daemon_log(LOG_WARNING, "Failed to change to directory '%s'", dir);
115 chdir("/");
116 }
117
118 for (i = 0; i < MAX_ARGS-1; i++)
119 if (!(args[i] = va_arg(ap, char*)))
120 break;
121 args[i] = NULL;
122
123 execv(prog, args);
124
125 daemon_log(LOG_ERR, "execv(%s) failed: %s", prog, strerror(errno));
126
127 fail:
128
129 _exit(EXIT_FAILURE);
130 }
131
132 close(p[1]);
133
134 FD_ZERO(&fds);
135 FD_SET(p[0], &fds);
136 sigfd = daemon_signal_fd();
137 FD_SET(sigfd, &fds);
138
139 n = 0;
140
141 for (;;) {
142 fd_set qfds = fds;
143
144 if (select(FD_SETSIZE, &qfds, NULL, NULL, NULL) < 0) {
145
146 if (errno == EINTR)
147 continue;
148
149 daemon_log(LOG_ERR, "select() failed: %s", strerror(errno));
150
151 saved_errno = errno;
152 close(p[0]);
153 errno = saved_errno;
154 return -1;
155 }
156
157 if (FD_ISSET(p[0], &qfds)) {
158 char c;
159
160 if (read(p[0], &c, 1) != 1)
161 break;
162
163 buf[n] = c;
164
165 if (c == '\n' || n >= sizeof(buf) - 2) {
166 if (c != '\n') n++;
167 buf[n] = 0;
168
169 if (buf[0])
170 daemon_log(LOG_INFO, "client: %s", buf);
171
172 n = 0;
173 } else
174 n++;
175 }
176
177 if (FD_ISSET(sigfd, &qfds)) {
178 int sig;
179
180 if ((sig = daemon_signal_next()) < 0) {
181 saved_errno = errno;
182 close(p[0]);
183 errno = saved_errno;
184 return -1;
185 }
186
187 if (sig != SIGCHLD) {
188 daemon_log(LOG_WARNING, "Killing child.");
189 kill(pid, SIGTERM);
190 }
191 }
192 }
193
194 if (n > 0) {
195 buf[n] = 0;
196 daemon_log(LOG_WARNING, "client: %s", buf);
197 }
198
199 close(p[0]);
200
201 for (;;) {
202 if (waitpid(pid, &r, 0) < 0) {
203
204 if (errno == EINTR)
205 continue;
206
207 daemon_log(LOG_ERR, "waitpid(): %s", strerror(errno));
208 return -1;
209 } else {
210 if (!WIFEXITED(r)) {
211 errno = ECANCELED;
212 return -1;
213 }
214
215 if (ret)
216 *ret = WEXITSTATUS(r);
217
218 return 0;
219 }
220 }
221 }
222
daemon_exec(const char * dir,int * ret,const char * prog,...)223 int daemon_exec(const char *dir, int *ret, const char *prog, ...) {
224 va_list ap;
225 int r;
226
227 va_start(ap, prog);
228 r = daemon_execv(dir, ret, prog, ap);
229 va_end(ap);
230
231 return r;
232 }
233