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 <sys/socket.h>
  28 #include <sys/un.h>
  29 #include <sys/wait.h>
  30 #include <sys/select.h>
  31
  32 #include "udev.h"
  33
  34 extern char **environ;
  35
  36 int pass_env_to_socket(const char *sockname, const char *devpath, const char *action)
  37 {
  38         int sock;
  39         struct sockaddr_un saddr;
  40         socklen_t addrlen;
  41         char buf[2048];
  42         size_t bufpos = 0;
  43         int i;
  44         ssize_t count;
  45         int retval = 0;
  46
  47         dbg("pass environment to socket '%s'", sockname);
  48         sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
  49         memset(&saddr, 0x00, sizeof(struct sockaddr_un));
  50         saddr.sun_family = AF_LOCAL;
  51         /* abstract namespace only */
  52         strcpy(&saddr.sun_path[1], sockname);
  53         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
  54
  55         bufpos = snprintf(buf, sizeof(buf)-1, "%s@%s", action, devpath);
  56         bufpos++;
  57         for (i = 0; environ[i] != NULL && bufpos < sizeof(buf); i++) {
  58                 bufpos += strlcpy(&buf[bufpos], environ[i], sizeof(buf) - bufpos-1);
  59                 bufpos++;
  60         }
  61
  62         count = sendto(sock, &buf, bufpos, 0, (struct sockaddr *)&saddr, addrlen);
  63         if (count < 0)
  64                 retval = -1;
  65         info("passed %zi bytes to socket '%s', ", count, sockname);
  66
  67         close(sock);
  68         return retval;
  69 }
  70
  71 int run_program(const char *command, const char *subsystem,
  72                 char *result, size_t ressize, size_t *reslen, int log)
  73 {
  74         int retval = 0;
  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
  85         /* build argv from comand */
  86         strlcpy(arg, command, sizeof(arg));
  87         i = 0;
  88         if (strchr(arg, ' ') != NULL) {
  89                 char *pos = arg;
  90
  91                 while (pos != NULL) {
  92                         if (pos[0] == '\'') {
  93                                 /* don't separate if in apostrophes */
  94                                 pos++;
  95                                 argv[i] = strsep(&pos, "\'");
  96                                 while (pos != NULL && pos[0] == ' ')
  97                                         pos++;
  98                         } else {
  99                                 argv[i] = strsep(&pos, " ");
 100                         }
 101                         dbg("arg[%i] '%s'", i, argv[i]);
 102                         i++;
 103                 }
 104                 argv[i] = NULL;
 105         } else {
 106                 argv[0] = arg;
 107                 argv[1] = NULL;
 108         }
 109         info("'%s'", command);
 110
 111         /* prepare pipes from child to parent */
 112         if (result || log) {
 113                 if (pipe(outpipe) != 0) {
 114                         err("pipe failed: %s", strerror(errno));
 115                         return -1;
 116                 }
 117         }
 118         if (log) {
 119                 if (pipe(errpipe) != 0) {
 120                         err("pipe failed: %s", strerror(errno));
 121                         return -1;
 122                 }
 123         }
 124
 125         /* allow programs in /lib/udev called without the path */
 126         if (strchr(argv[0], '/') == NULL) {
 127                 strlcpy(program, "/lib/udev/", sizeof(program));
 128                 strlcat(program, argv[0], sizeof(program));
 129                 argv[0] = program;
 130         }
 131
 132         pid = fork();
 133         switch(pid) {
 134         case 0:
 135                 /* child closes parent ends of pipes */
 136                 if (outpipe[READ_END] > 0)
 137                         close(outpipe[READ_END]);
 138                 if (errpipe[READ_END] > 0)
 139                         close(errpipe[READ_END]);
 140
 141                 /* discard child output or connect to pipe */
 142                 devnull = open("/dev/null", O_RDWR);
 143                 if (devnull > 0) {
 144                         dup2(devnull, STDIN_FILENO);
 145                         if (outpipe[WRITE_END] < 0)
 146                                 dup2(devnull, STDOUT_FILENO);
 147                         if (errpipe[WRITE_END] < 0)
 148                                 dup2(devnull, STDERR_FILENO);
 149                         close(devnull);
 150                 } else
 151                         err("open /dev/null failed: %s", strerror(errno));
 152                 if (outpipe[WRITE_END] > 0) {
 153                         dup2(outpipe[WRITE_END], STDOUT_FILENO);
 154                         close(outpipe[WRITE_END]);
 155                 }
 156                 if (errpipe[WRITE_END] > 0) {
 157                         dup2(errpipe[WRITE_END], STDERR_FILENO);
 158                         close(errpipe[WRITE_END]);
 159                 }
 160                 execv(argv[0], argv);
 161
 162                 /* we should never reach this */
 163                 err("exec of program '%s' failed", argv[0]);
 164                 _exit(1);
 165         case -1:
 166                 err("fork of '%s' failed: %s", argv[0], strerror(errno));
 167                 return -1;
 168         default:
 169                 /* read from child if requested */
 170                 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 171                         ssize_t count;
 172                         size_t respos = 0;
 173
 174                         /* parent closes child ends of pipes */
 175                         if (outpipe[WRITE_END] > 0)
 176                                 close(outpipe[WRITE_END]);
 177                         if (errpipe[WRITE_END] > 0)
 178                                 close(errpipe[WRITE_END]);
 179
 180                         /* read child output */
 181                         while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 182                                 int fdcount;
 183                                 fd_set readfds;
 184
 185                                 FD_ZERO(&readfds);
 186                                 if (outpipe[READ_END] > 0)
 187                                         FD_SET(outpipe[READ_END], &readfds);
 188                                 if (errpipe[READ_END] > 0)
 189                                         FD_SET(errpipe[READ_END], &readfds);
 190                                 fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
 191                                 if (fdcount < 0) {
 192                                         if (errno == EINTR)
 193                                                 continue;
 194                                         retval = -1;
 195                                         break;
 196                                 }
 197
 198                                 /* get stdout */
 199                                 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
 200                                         char inbuf[1024];
 201                                         char *pos;
 202                                         char *line;
 203
 204                                         count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
 205                                         if (count <= 0) {
 206                                                 close(outpipe[READ_END]);
 207                                                 outpipe[READ_END] = -1;
 208                                                 if (count < 0) {
 209                                                         err("stdin read failed: %s", strerror(errno));
 210                                                         retval = -1;
 211                                                 }
 212                                                 continue;
 213                                         }
 214                                         inbuf[count] = '\0';
 215
 216                                         /* store result for rule processing */
 217                                         if (result) {
 218                                                 if (respos + count < ressize) {
 219                                                         memcpy(&result[respos], inbuf, count);
 220                                                         respos += count;
 221                                                 } else {
 222                                                         err("ressize %ld too short", (long)ressize);
 223                                                         retval = -1;
 224                                                 }
 225                                         }
 226                                         pos = inbuf;
 227                                         while ((line = strsep(&pos, "\n")))
 228                                                 if (pos || line[0] != '\0')
 229                                                         info("'%s' (stdout) '%s'", argv[0], line);
 230                                 }
 231
 232                                 /* get stderr */
 233                                 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
 234                                         char errbuf[1024];
 235                                         char *pos;
 236                                         char *line;
 237
 238                                         count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
 239                                         if (count <= 0) {
 240                                                 close(errpipe[READ_END]);
 241                                                 errpipe[READ_END] = -1;
 242                                                 if (count < 0)
 243                                                         err("stderr read failed: %s", strerror(errno));
 244                                                 continue;
 245                                         }
 246                                         errbuf[count] = '\0';
 247                                         pos = errbuf;
 248                                         while ((line = strsep(&pos, "\n")))
 249                                                 if (pos || line[0] != '\0')
 250                                                         info("'%s' (stderr) '%s'", argv[0], line);
 251                                 }
 252                         }
 253                         if (outpipe[READ_END] > 0)
 254                                 close(outpipe[READ_END]);
 255                         if (errpipe[READ_END] > 0)
 256                                 close(errpipe[READ_END]);
 257
 258                         /* return the childs stdout string */
 259                         if (result) {
 260                                 result[respos] = '\0';
 261                                 dbg("result='%s'", result);
 262                                 if (reslen)
 263                                         *reslen = respos;
 264                         }
 265                 }
 266                 waitpid(pid, &status, 0);
 267                 if (WIFEXITED(status)) {
 268                         info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));
 269                         if (WEXITSTATUS(status) != 0)
 270                                 retval = -1;
 271                 } else {
 272                         err("'%s' abnormal exit", argv[0]);
 273                         retval = -1;
 274                 }
 275         }
 276
 277         return retval;
 278 }