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 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 } 222 223 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
