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
  34 #include "udev_libc_wrapper.h"
  35 #include "udev.h"
  36 #include "logging.h"
  37 #include "udev_utils.h"
  38 #include "list.h"
  39
  40
  41 int pass_env_to_socket(const char *sockname, const char *devpath, const char *action)
  42 {
  43         int sock;
  44         struct sockaddr_un saddr;
  45         socklen_t addrlen;
  46         char buf[2048];
  47         size_t bufpos = 0;
  48         int i;
  49         ssize_t count;
  50         int retval = 0;
  51
  52         dbg("pass environment to socket '%s'", sockname);
  53         sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
  54         memset(&saddr, 0x00, sizeof(struct sockaddr_un));
  55         saddr.sun_family = AF_LOCAL;
  56         /* only abstract namespace is supported */
  57         strcpy(&saddr.sun_path[1], sockname);
  58         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
  59
  60         bufpos = snprintf(buf, sizeof(buf)-1, "%s@%s", action, devpath);
  61         bufpos++;
  62         for (i = 0; environ[i] != NULL && bufpos < sizeof(buf); i++) {
  63                 bufpos += strlcpy(&buf[bufpos], environ[i], sizeof(buf) - bufpos-1);
  64                 bufpos++;
  65         }
  66
  67         count = sendto(sock, &buf, bufpos, 0, (struct sockaddr *)&saddr, addrlen);
  68         if (count < 0)
  69                 retval = -1;
  70         info("passed %zi bytes to socket '%s', ", count, sockname);
  71
  72         close(sock);
  73         return retval;
  74 }
  75
  76 int run_program(const char *command, const char *subsystem,
  77                 char *result, size_t ressize, size_t *reslen, int log)
  78 {
  79         int retval = 0;
  80         int status;
  81         int outpipe[2] = {-1, -1};
  82         int errpipe[2] = {-1, -1};
  83         pid_t pid;
  84         char arg[PATH_SIZE];
  85         char program[PATH_SIZE];
  86         char *argv[(sizeof(arg) / 2) + 1];
  87         int devnull;
  88         int i;
  89
  90         strlcpy(arg, command, sizeof(arg));
  91         i = 0;
  92         if (strchr(arg, ' ')) {
  93                 char *pos = arg;
  94                 while (pos != NULL) {
  95                         if (pos[0] == '\'') {
  96                                 /* don't separate if in apostrophes */
  97                                 pos++;
  98                                 argv[i] = strsep(&pos, "\'");
  99                                 while (pos && pos[0] == ' ')
 100                                         pos++;
 101                         } else {
 102                                 argv[i] = strsep(&pos, " ");
 103                         }
 104                         dbg("arg[%i] '%s'", i, argv[i]);
 105                         i++;
 106                 }
 107                 argv[i] = NULL;
 108                 info("'%s'", command);
 109         } else {
 110                 argv[0] = arg;
 111                 argv[1] = (char *) subsystem;
 112                 argv[2] = NULL;
 113                 info("'%s' '%s'", arg, argv[1]);
 114         }
 115
 116         /* prepare pipes from child to parent */
 117         if (result || log) {
 118                 if (pipe(outpipe) != 0) {
 119                         err("pipe failed: %s", strerror(errno));
 120                         return -1;
 121                 }
 122         }
 123         if (log) {
 124                 if (pipe(errpipe) != 0) {
 125                         err("pipe failed: %s", strerror(errno));
 126                         return -1;
 127                 }
 128         }
 129
 130         /* allow programs in /lib/udev called without the path */
 131         if (strchr(argv[0], '/') == NULL) {
 132                 strlcpy(program, "/lib/udev/", sizeof(program));
 133                 strlcat(program, argv[0], sizeof(program));
 134                 argv[0] = program;
 135         }
 136
 137         pid = fork();
 138         switch(pid) {
 139         case 0:
 140                 /* child closes parent ends of pipes */
 141                 if (outpipe[READ_END] > 0)
 142                         close(outpipe[READ_END]);
 143                 if (errpipe[READ_END] > 0)
 144                         close(errpipe[READ_END]);
 145
 146                 /* discard child output or connect to pipe */
 147                 devnull = open("/dev/null", O_RDWR);
 148                 if (devnull > 0) {
 149                         dup2(devnull, STDIN_FILENO);
 150                         if (outpipe[WRITE_END] < 0)
 151                                 dup2(devnull, STDOUT_FILENO);
 152                         if (errpipe[WRITE_END] < 0)
 153                                 dup2(devnull, STDERR_FILENO);
 154                         close(devnull);
 155                 } else
 156                         err("open /dev/null failed: %s", strerror(errno));
 157                 if (outpipe[WRITE_END] > 0)
 158                         dup2(outpipe[WRITE_END], STDOUT_FILENO);
 159                 if (errpipe[WRITE_END] > 0)
 160                         dup2(errpipe[WRITE_END], STDERR_FILENO);
 161                 execv(argv[0], argv);
 162
 163                 /* we should never reach this */
 164                 err("exec of program '%s' failed", argv[0]);
 165                 _exit(1);
 166         case -1:
 167                 err("fork of '%s' failed: %s", argv[0], strerror(errno));
 168                 return -1;
 169         default:
 170                 /* read from child if requested */
 171                 if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 172                         ssize_t count;
 173                         size_t respos = 0;
 174
 175                         /* parent closes child ends of pipes */
 176                         if (outpipe[WRITE_END] > 0)
 177                                 close(outpipe[WRITE_END]);
 178                         if (errpipe[WRITE_END] > 0)
 179                                 close(errpipe[WRITE_END]);
 180
 181                         /* read child output */
 182                         while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) {
 183                                 int fdcount;
 184                                 fd_set readfds;
 185
 186                                 FD_ZERO(&readfds);
 187                                 if (outpipe[READ_END] > 0)
 188                                         FD_SET(outpipe[READ_END], &readfds);
 189                                 if (errpipe[READ_END] > 0)
 190                                         FD_SET(errpipe[READ_END], &readfds);
 191                                 fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL);
 192                                 if (fdcount < 0) {
 193                                         if (errno == EINTR)
 194                                                 continue;
 195                                         retval = -1;
 196                                         break;
 197                                 }
 198
 199                                 /* get stdout */
 200                                 if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) {
 201                                         char inbuf[1024];
 202                                         char *pos;
 203                                         char *line;
 204
 205                                         count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1);
 206                                         if (count <= 0) {
 207                                                 close(outpipe[READ_END]);
 208                                                 outpipe[READ_END] = -1;
 209                                                 if (count < 0) {
 210                                                         err("stdin read failed: %s", strerror(errno));
 211                                                         retval = -1;
 212                                                 }
 213                                                 continue;
 214                                         }
 215                                         inbuf[count] = '\0';
 216
 217                                         /* store result for rule processing */
 218                                         if (result) {
 219                                                 if (respos + count < ressize) {
 220                                                         memcpy(&result[respos], inbuf, count);
 221                                                         respos += count;
 222                                                 } else {
 223                                                         err("ressize %ld too short", (long)ressize);
 224                                                         retval = -1;
 225                                                 }
 226                                         }
 227                                         pos = inbuf;
 228                                         while ((line = strsep(&pos, "\n")))
 229                                                 if (pos || line[0] != '\0')
 230                                                         info("'%s' (stdout) '%s'", argv[0], line);
 231                                 }
 232
 233                                 /* get stderr */
 234                                 if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
 235                                         char errbuf[1024];
 236                                         char *pos;
 237                                         char *line;
 238
 239                                         count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1);
 240                                         if (count <= 0) {
 241                                                 close(errpipe[READ_END]);
 242                                                 errpipe[READ_END] = -1;
 243                                                 if (count < 0)
 244                                                         err("stderr read failed: %s", strerror(errno));
 245                                                 continue;
 246                                         }
 247                                         errbuf[count] = '\0';
 248                                         pos = errbuf;
 249                                         while ((line = strsep(&pos, "\n")))
 250                                                 if (pos || line[0] != '\0')
 251                                                         info("'%s' (stderr) '%s'", argv[0], line);
 252                                 }
 253                         }
 254                         if (outpipe[READ_END] > 0)
 255                                 close(outpipe[READ_END]);
 256                         if (errpipe[READ_END] > 0)
 257                                 close(errpipe[READ_END]);
 258
 259                         /* return the childs stdout string */
 260                         if (result) {
 261                                 result[respos] = '\0';
 262                                 dbg("result='%s'", result);
 263                                 if (reslen)
 264                                         *reslen = respos;
 265                         }
 266                 }
 267                 waitpid(pid, &status, 0);
 268                 if (WIFEXITED(status)) {
 269                         info("'%s' returned with status %i", argv[0], WEXITSTATUS(status));
 270                         if (WEXITSTATUS(status) != 0)
 271                                 retval = -1;
 272                 } else {
 273                         err("'%s' abnormal exit", argv[0]);
 274                         retval = -1;
 275                 }
 276         }
 277
 278         return retval;
 279 }