-static int execute_program_pipe(const char *command, const char *subsystem, char *value, int len)
-{
- int retval;
- int count;
- int status;
- int pipefds[2];
- pid_t pid;
- char *pos;
- char arg[PATH_SIZE];
- char *argv[(sizeof(arg) / 2) + 1];
- int devnull;
- int i;
-
- strlcpy(arg, command, sizeof(arg));
- i = 0;
- if (strchr(arg, ' ')) {
- pos = arg;
- while (pos != NULL) {
- if (pos[0] == '\'') {
- /* don't separate if in apostrophes */
- pos++;
- argv[i] = strsep(&pos, "\'");
- while (pos && pos[0] == ' ')
- pos++;
- } else {
- argv[i] = strsep(&pos, " ");
- }
- dbg("arg[%i] '%s'", i, argv[i]);
- i++;
- }
- argv[i] = NULL;
- dbg("execute '%s' with parsed arguments", arg);
- } else {
- argv[0] = arg;
- argv[1] = (char *) subsystem;
- argv[2] = NULL;
- dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]);
- }
-
- retval = pipe(pipefds);
- if (retval != 0) {
- err("pipe failed");
- return -1;
- }
-
- pid = fork();
- switch(pid) {
- case 0:
- /* child dup2 write side of pipe to STDOUT */
- devnull = open("/dev/null", O_RDWR);
- if (devnull >= 0) {
- dup2(devnull, STDIN_FILENO);
- dup2(devnull, STDERR_FILENO);
- close(devnull);
- }
- dup2(pipefds[1], STDOUT_FILENO);
- retval = execv(arg, argv);
- err("exec of program failed");
- _exit(1);
- case -1:
- err("fork of '%s' failed", arg);
- retval = -1;
- break;
- default:
- /* parent reads from pipefds[0] */
- close(pipefds[1]);
- retval = 0;
- i = 0;
- while (1) {
- count = read(pipefds[0], value + i, len - i-1);
- if (count < 0) {
- err("read failed with '%s'", strerror(errno));
- retval = -1;
- }
-
- if (count == 0)
- break;
-
- i += count;
- if (i >= len-1) {
- err("result len %d too short", len);
- retval = -1;
- break;
- }
- }
- value[i] = '\0';
-
- close(pipefds[0]);
- waitpid(pid, &status, 0);
-
- if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
- dbg("exec program status 0x%x", status);
- retval = -1;
- }
- }
-
- if (!retval) {
- remove_trailing_char(value, '\n');
- dbg("result is '%s'", value);
- replace_untrusted_chars(value);
- } else
- value[0] = '\0';
-
- return retval;
-}
-