udev_utils_run.c

   1 /*
   2  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  *      This program is free software; you can redistribute it and/or modify it
   5  *      under the terms of the GNU General Public License as published by the
   6  *      Free Software Foundation version 2 of the License.
   7  *
   8  *      This program is distributed in the hope that it will be useful, but
   9  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  *      General Public License for more details.
  12  *
  13  *      You should have received a copy of the GNU General Public License along
  14  *      with this program; if not, write to the Free Software Foundation, Inc.,
  15  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16  *
  17  */
  18
  19
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <ctype.h>
  27 #include <syslog.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30 #include <sys/wait.h>
  31 #include <sys/select.h>
  32
  33 #include "udev.h"
  34
  35 extern char **environ;
  36
  37 int pass_env_to_socket(const char *sockname, const char *devpath, const char *action)
  38 {
  39         int sock;
  40         struct sockaddr_un saddr;
  41         socklen_t addrlen;
  42         char buf[2048];
  43         size_t bufpos = 0;
  44         int i;
  45         ssize_t count;
  46         int retval = 0;
  47
  48         dbg("pass environment to socket '%s'", sockname);
  49         sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
  50         memset(&saddr, 0x00, sizeof(struct sockaddr_un));
  51         saddr.sun_family = AF_LOCAL;
  52         /* abstract namespace only */
  53         strcpy(&saddr.sun_path[1], sockname);
  54         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
  55
  56         bufpos = snprintf(buf, sizeof(buf)-1, "%s@%s", action, devpath);
  57         bufpos++;
  58         for (i = 0; environ[i] != NULL && bufpos < sizeof(buf); i++) {
  59                 bufpos += strlcpy(&buf[bufpos], environ[i], sizeof(buf) - bufpos-1);
  60                 bufpos++;
  61         }
  62
  63         count = sendto(sock, &buf, bufpos, 0, (struct sockaddr *)&saddr, addrlen);
  64         if (count < 0)
  65                 retval = -1;
  66         info("passed %zi bytes to socket '%s', ", count, sockname);
  67
  68         close(sock);
  69         return retval;
  70 }
  71
  72 int run_program(const char *command, const char *subsystem,
  73                 char *result, size_t ressize, size_t *reslen)
  74 {
  75         int status;
  76         int outpipe[2] = {-1, -1};
  77         int errpipe[2] = {-1, -1};
  78         pid_t pid;
  79         char arg[PATH_SIZE];
  80         char program[PATH_SIZE];
  81         char *argv[(sizeof(arg) / 2) + 1];
  82         int devnull;
  83         int i;
  84         int retval = 0;
  85
  86         /* build argv from comand */
  87         strlcpy(arg, command, sizeof(arg));
  88         i = 0;
  89         if (strchr(arg, ' ') != NULL) {
  90                 char *pos = arg;
  91
  92                 while (pos != NULL) {
  93                         if (pos[0] == '\'') {
  94                                 /* don't separate if in apostrophes */
  95                                 pos++;
  96                                 argv[i] = strsep(&pos, "\'");
  97                                 while (pos != NULL && pos[0] == ' ')
  98                                         pos++;
  99                         } else {
 100                                 argv[i] = strsep(&pos, " ");
 101                         }
 102                         dbg("arg[%i] '%s'", i, argv[i]);
 103                         i++;
 104                 }
 105                 argv[i] = NULL;
 106         } else {
 107                 argv[0] = arg;
 108                 argv[1] = NULL;
 109         }
 110         info("'%s'", command);
 111
 112         /* prepare pipes from child to parent */
 113         if (result != NULL || udev_log_priority >= LOG_INFO) {
 114                 if (pipe(outpipe) != 0) {
 115                         err("pipe failed: %s", strerror(errno));
 116                         return -1;
 117                 }
 118         }
 119         if (udev_log_priority >= LOG_INFO) {
 120                 if (pipe(errpipe) != 0) {
 121                         err("pipe failed: %s", strerror(errno));
 122                         return -1;
 123                 }
 124         }
 125
 126         /* allow programs in /lib/udev called without the path */
 127         if (strchr(argv[0], '/') == NULL) {
 128                 strlcpy(program, "/lib/udev/", sizeof(program));
 129                 strlcat(program, argv[0], sizeof(program));
 130                 argv[0] = program;
 131         }
 132
 133         pid = fork();
 134         switch(pid) {
 135         case 0:
 136                 /* child closes parent ends of pipes */
 137                 if (outpipe[READ_END] > 0)
 138                         close(outpipe[READ_END]);
 139                 if (errpipe[READ_END] > 0)
 140                         close(errpipe[READ_END]);
 141
 142                 /* discard child output or connect to pipe */
 143                 devnull = open("/dev/null", O_RDWR);
 144                 if (devnull > 0) {
 145                         dup2(devnull, STDIN_FILENO);
 146                         if (outpipe[WRITE_END] < 0)
 147                                 dup2(devnull, STDOUT_FILENO);
 148                         if (errpipe[WRITE_END] < 0)
 149                                 dup2(devnull, STDERR_FILENO);
 150                         close(devnull);
 151                 } else
 152                         err("open /dev/null failed: %s", strerror(errno));
 153                 if (outpipe[WRITE_END] > 0) {
 154                         dup2(outpipe[WRITE_END], STDOUT_FILENO);
 155                         close(outpipe[WRITE_END]);
 156                 }
 157                 if (errpipe[WRITE_END] > 0) {
 158                         dup2(errpipe[WRITE_END], STDERR_FILENO);
 159                         close(errpipe[WRITE_END]);
 160                 }
 161                 execv(argv[0], argv);
 162                 if (errno == ENOENT || errno == ENOTDIR) {
 163                         /* may be on a filesytem which is not mounted right now */
 164                         info("program '%s' not found", argv[0]);
 165                 } else {
 166                         /* other problems */
 167                         err("exec of program '%s' failed", argv[0]);
 168                 }
 169                 _exit(1);
 170         case -1:
 171                 err("fork of '%s' failed: %s", argv[0], strerror(errno));
 172                 return -1;
 173         default:
 174                 /* read from child if requested */
 175                 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 176                         ssize_t count;
 177                         size_t respos = 0;
 178
 179                         /* parent closes child ends of pipes */
 180                         if (outpipe[WRITE_END] > 0)
 181                                 close(outpipe[WRITE_END]);
 182                         if (errpipe[WRITE_END] > 0)
 183                                 close(errpipe[WRITE_END]);
 184
 185                         /* read child output */
 186                         while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 187                                 int fdcount;
 188                                 fd_set readfds;
 189
 190                                 FD_ZERO(&readfds);
 191                                 if (outpipe[READ_END] > 0)
 192                                         FD_SET(outpipe[READ_END], &readfds);
 193                                 if (errpipe[READ_END] > 0)
 194                                         FD_SET(errpipe[READ_END], &readfds);
 195                                 fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
 196                                 if (fdcount < 0) {
 197                                         if (errno == EINTR)
 198                                                 continue;
 199                                         retval = -1;
 200                                         break;
 201                                 }
 202
 203                                 /* get stdout */
 204                                 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
 205                                         char inbuf[1024];
 206                                         char *pos;
 207                                         char *line;
 208
 209                                         count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
 210                                         if (count <= 0) {
 211                                                 close(outpipe[READ_END]);
 212                                                 outpipe[READ_END] = -1;
 213                                                 if (count < 0) {
 214                                                         err("stdin read failed: %s", strerror(errno));
 215                                                         retval = -1;
 216                                                 }
 217                                                 continue;
 218                                         }
 219                                         inbuf[count] = '\0';
 220
 221                                         /* store result for rule processing */
 222                                         if (result) {
 223                                                 if (respos + count < ressize) {
 224                                                         memcpy(&result[respos], inbuf, count);
 225                                                         respos += count;
 226                                                 } else {
 227                                                         err("ressize %ld too short", (long)ressize);
 228                                                         retval = -1;
 229                                                 }
 230                                         }
 231                                         pos = inbuf;
 232                                         while ((line = strsep(&pos, "\n")))
 233                                                 if (pos || line[0] != '\0')
 234                                                         info("'%s' (stdout) '%s'", argv[0], line);
 235                                 }
 236
 237                                 /* get stderr */
 238                                 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
 239                                         char errbuf[1024];
 240                                         char *pos;
 241                                         char *line;
 242
 243                                         count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
 244                                         if (count <= 0) {
 245                                                 close(errpipe[READ_END]);
 246                                                 errpipe[READ_END] = -1;
 247                                                 if (count < 0)
 248                                                         err("stderr read failed: %s", strerror(errno));
 249                                                 continue;
 250                                         }
 251                                         errbuf[count] = '\0';
 252                                         pos = errbuf;
 253                                         while ((line = strsep(&pos, "\n")))
 254                                                 if (pos || line[0] != '\0')
 255                                                         info("'%s' (stderr) '%s'", argv[0], line);
 256                                 }
 257                         }
 258                         if (outpipe[READ_END] > 0)
 259                                 close(outpipe[READ_END]);
 260                         if (errpipe[READ_END] > 0)
 261                                 close(errpipe[READ_END]);
 262
 263                         /* return the childs stdout string */
 264                         if (result) {
 265                                 result[respos] = '\0';
 266                                 dbg("result='%s'", result);
 267                                 if (reslen)
 268                                         *reslen = respos;
 269                         }
 270                 }
 271                 waitpid(pid, &status, 0);
 272                 if (WIFEXITED(status)) {
 273                         info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));
 274                         if (WEXITSTATUS(status) != 0)
 275                                 retval = -1;
 276                 } else {
 277                         err("'%s' abnormal exit", argv[0]);
 278                         retval = -1;
 279                 }
 280         }
 281
 282         return retval;
 283 }