udev_utils_run.c

   1 /*
   2  * udev_utils_run.c - execute programs from udev and read its output
   3  *
   4  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  *      This program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  *
  10  *      This program is distributed in the hope that it will be useful, but
  11  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *      General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License along
  16  *      with this program; if not, write to the Free Software Foundation, Inc.,
  17  *      675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  */
  20
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <ctype.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <sys/wait.h>
  32 #include <sys/select.h>
  33 #include <unistd.h>
  34
  35 #include "udev.h"
  36
  37 extern char **environ;
  38
  39 int pass_env_to_socket(const char *sockname, const char *devpath, const char *action)
  40 {
  41         int sock;
  42         struct sockaddr_un saddr;
  43         socklen_t addrlen;
  44         char buf[2048];
  45         size_t bufpos = 0;
  46         int i;
  47         ssize_t count;
  48         int retval = 0;
  49
  50         dbg("pass environment to socket '%s'", sockname);
  51         sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
  52         memset(&saddr, 0x00, sizeof(struct sockaddr_un));
  53         saddr.sun_family = AF_LOCAL;
  54         /* only abstract namespace is supported */
  55         strcpy(&saddr.sun_path[1], sockname);
  56         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
  57
  58         bufpos = snprintf(buf, sizeof(buf)-1, "%s@%s", action, devpath);
  59         bufpos++;
  60         for (i = 0; environ[i] != NULL && bufpos < sizeof(buf); i++) {
  61                 bufpos += strlcpy(&buf[bufpos], environ[i], sizeof(buf) - bufpos-1);
  62                 bufpos++;
  63         }
  64
  65         count = sendto(sock, &buf, bufpos, 0, (struct sockaddr *)&saddr, addrlen);
  66         if (count < 0)
  67                 retval = -1;
  68         info("passed %zi bytes to socket '%s', ", count, sockname);
  69
  70         close(sock);
  71         return retval;
  72 }
  73
  74 int run_program(const char *command, const char *subsystem,
  75                 char *result, size_t ressize, size_t *reslen, int log)
  76 {
  77         int retval = 0;
  78         int status;
  79         int outpipe[2] = {-1, -1};
  80         int errpipe[2] = {-1, -1};
  81         pid_t pid;
  82         char arg[PATH_SIZE];
  83         char program[PATH_SIZE];
  84         char *argv[(sizeof(arg) / 2) + 1];
  85         int devnull;
  86         int i;
  87
  88         strlcpy(arg, command, sizeof(arg));
  89         i = 0;
  90         if (strchr(arg, ' ')) {
  91                 char *pos = arg;
  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 && 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                 info("'%s'", command);
 107         } else {
 108                 argv[0] = arg;
 109                 argv[1] = (char *) subsystem;
 110                 argv[2] = NULL;
 111                 info("'%s' '%s'", arg, argv[1]);
 112         }
 113
 114         /* prepare pipes from child to parent */
 115         if (result || log) {
 116                 if (pipe(outpipe) != 0) {
 117                         err("pipe failed: %s", strerror(errno));
 118                         return -1;
 119                 }
 120         }
 121         if (log) {
 122                 if (pipe(errpipe) != 0) {
 123                         err("pipe failed: %s", strerror(errno));
 124                         return -1;
 125                 }
 126         }
 127
 128         /* allow programs in /lib/udev called without the path */
 129         if (strchr(argv[0], '/') == NULL) {
 130                 strlcpy(program, "/lib/udev/", sizeof(program));
 131                 strlcat(program, argv[0], sizeof(program));
 132                 argv[0] = program;
 133         }
 134
 135         pid = fork();
 136         switch(pid) {
 137         case 0:
 138                 /* child closes parent ends of pipes */
 139                 if (outpipe[READ_END] > 0)
 140                         close(outpipe[READ_END]);
 141                 if (errpipe[READ_END] > 0)
 142                         close(errpipe[READ_END]);
 143
 144                 /* discard child output or connect to pipe */
 145                 devnull = open("/dev/null", O_RDWR);
 146                 if (devnull > 0) {
 147                         dup2(devnull, STDIN_FILENO);
 148                         if (outpipe[WRITE_END] < 0)
 149                                 dup2(devnull, STDOUT_FILENO);
 150                         if (errpipe[WRITE_END] < 0)
 151                                 dup2(devnull, STDERR_FILENO);
 152                         close(devnull);
 153                 } else
 154                         err("open /dev/null failed: %s", strerror(errno));
 155                 if (outpipe[WRITE_END] > 0)
 156                         dup2(outpipe[WRITE_END], STDOUT_FILENO);
 157                 if (errpipe[WRITE_END] > 0)
 158                         dup2(errpipe[WRITE_END], STDERR_FILENO);
 159                 execv(argv[0], argv);
 160
 161                 /* we should never reach this */
 162                 err("exec of program '%s' failed", argv[0]);
 163                 _exit(1);
 164         case -1:
 165                 err("fork of '%s' failed: %s", argv[0], strerror(errno));
 166                 return -1;
 167         default:
 168                 /* read from child if requested */
 169                 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 170                         ssize_t count;
 171                         size_t respos = 0;
 172
 173                         /* parent closes child ends of pipes */
 174                         if (outpipe[WRITE_END] > 0)
 175                                 close(outpipe[WRITE_END]);
 176                         if (errpipe[WRITE_END] > 0)
 177                                 close(errpipe[WRITE_END]);
 178
 179                         /* read child output */
 180                         while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 181                                 int fdcount;
 182                                 fd_set readfds;
 183
 184                                 FD_ZERO(&readfds);
 185                                 if (outpipe[READ_END] > 0)
 186                                         FD_SET(outpipe[READ_END], &readfds);
 187                                 if (errpipe[READ_END] > 0)
 188                                         FD_SET(errpipe[READ_END], &readfds);
 189                                 fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
 190                                 if (fdcount < 0) {
 191                                         if (errno == EINTR)
 192                                                 continue;
 193                                         retval = -1;
 194                                         break;
 195                                 }
 196
 197                                 /* get stdout */
 198                                 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
 199                                         char inbuf[1024];
 200                                         char *pos;
 201                                         char *line;
 202
 203                                         count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
 204                                         if (count <= 0) {
 205                                                 close(outpipe[READ_END]);
 206                                                 outpipe[READ_END] = -1;
 207                                                 if (count < 0) {
 208                                                         err("stdin read failed: %s", strerror(errno));
 209                                                         retval = -1;
 210                                                 }
 211                                                 continue;
 212                                         }
 213                                         inbuf[count] = '\0';
 214
 215                                         /* store result for rule processing */
 216                                         if (result) {
 217                                                 if (respos + count < ressize) {
 218                                                         memcpy(&result[respos], inbuf, count);
 219                                                         respos += count;
 220                                                 } else {
 221                                                         err("ressize %ld too short", (long)ressize);
 222                                                         retval = -1;
 223                                                 }
 224                                         }
 225                                         pos = inbuf;
 226                                         while ((line = strsep(&pos, "\n")))
 227                                                 if (pos || line[0] != '\0')
 228                                                         info("'%s' (stdout) '%s'", argv[0], line);
 229                                 }
 230
 231                                 /* get stderr */
 232                                 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
 233                                         char errbuf[1024];
 234                                         char *pos;
 235                                         char *line;
 236
 237                                         count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
 238                                         if (count <= 0) {
 239                                                 close(errpipe[READ_END]);
 240                                                 errpipe[READ_END] = -1;
 241                                                 if (count < 0)
 242                                                         err("stderr read failed: %s", strerror(errno));
 243                                                 continue;
 244                                         }
 245                                         errbuf[count] = '\0';
 246                                         pos = errbuf;
 247                                         while ((line = strsep(&pos, "\n")))
 248                                                 if (pos || line[0] != '\0')
 249                                                         info("'%s' (stderr) '%s'", argv[0], line);
 250                                 }
 251                         }
 252                         if (outpipe[READ_END] > 0)
 253                                 close(outpipe[READ_END]);
 254                         if (errpipe[READ_END] > 0)
 255                                 close(errpipe[READ_END]);
 256
 257                         /* return the childs stdout string */
 258                         if (result) {
 259                                 result[respos] = '\0';
 260                                 dbg("result='%s'", result);
 261                                 if (reslen)
 262                                         *reslen = respos;
 263                         }
 264                 }
 265                 waitpid(pid, &status, 0);
 266                 if (WIFEXITED(status)) {
 267                         info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));
 268                         if (WEXITSTATUS(status) != 0)
 269                                 retval = -1;
 270                 } else {
 271                         err("'%s' abnormal exit", argv[0]);
 272                         retval = -1;
 273                 }
 274         }
 275
 276         return retval;
 277 }