diff options
Diffstat (limited to 'udev/udev-util.c')
| -rw-r--r-- | udev/udev-util.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/udev/udev-util.c b/udev/udev-util.c index 59c4d194dd..d17a151966 100644 --- a/udev/udev-util.c +++ b/udev/udev-util.c @@ -25,6 +25,7 @@ #include <ctype.h> #include <pwd.h> #include <grp.h> +#include <sys/wait.h> #include "udev.h" @@ -158,3 +159,215 @@ extern gid_t lookup_group(struct udev *udev, const char *group) return gid; } + +int run_program(struct udev *udev, const char *command, char **envp, + char *result, size_t ressize, size_t *reslen) +{ + int status; + int outpipe[2] = {-1, -1}; + int errpipe[2] = {-1, -1}; + pid_t pid; + char arg[UTIL_PATH_SIZE]; + char program[UTIL_PATH_SIZE]; + char *argv[(sizeof(arg) / 2) + 1]; + int devnull; + int i; + int err = 0; + + /* build argv from command */ + util_strlcpy(arg, command, sizeof(arg)); + i = 0; + if (strchr(arg, ' ') != NULL) { + char *pos = arg; + + while (pos != NULL && pos[0] != '\0') { + if (pos[0] == '\'') { + /* do not separate quotes */ + pos++; + argv[i] = strsep(&pos, "\'"); + while (pos != NULL && pos[0] == ' ') + pos++; + } else { + argv[i] = strsep(&pos, " "); + } + dbg(udev, "arg[%i] '%s'\n", i, argv[i]); + i++; + } + argv[i] = NULL; + } else { + argv[0] = arg; + argv[1] = NULL; + } + info(udev, "'%s'\n", command); + + /* prepare pipes from child to parent */ + if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) { + if (pipe(outpipe) != 0) { + err(udev, "pipe failed: %m\n"); + return -1; + } + } + if (udev_get_log_priority(udev) >= LOG_INFO) { + if (pipe(errpipe) != 0) { + err(udev, "pipe failed: %m\n"); + return -1; + } + } + + /* allow programs in /lib/udev/ to be called without the path */ + if (strchr(argv[0], '/') == NULL) { + util_strlcpy(program, UDEV_PREFIX "/lib/udev/", sizeof(program)); + util_strlcat(program, argv[0], sizeof(program)); + argv[0] = program; + } + + pid = fork(); + switch(pid) { + case 0: + /* child closes parent ends of pipes */ + if (outpipe[READ_END] > 0) + close(outpipe[READ_END]); + if (errpipe[READ_END] > 0) + close(errpipe[READ_END]); + + /* discard child output or connect to pipe */ + devnull = open("/dev/null", O_RDWR); + if (devnull > 0) { + dup2(devnull, STDIN_FILENO); + if (outpipe[WRITE_END] < 0) + dup2(devnull, STDOUT_FILENO); + if (errpipe[WRITE_END] < 0) + dup2(devnull, STDERR_FILENO); + close(devnull); + } else + err(udev, "open /dev/null failed: %m\n"); + if (outpipe[WRITE_END] > 0) { + dup2(outpipe[WRITE_END], STDOUT_FILENO); + close(outpipe[WRITE_END]); + } + if (errpipe[WRITE_END] > 0) { + dup2(errpipe[WRITE_END], STDERR_FILENO); + close(errpipe[WRITE_END]); + } + execve(argv[0], argv, envp); + if (errno == ENOENT || errno == ENOTDIR) { + /* may be on a filesytem which is not mounted right now */ + info(udev, "program '%s' not found\n", argv[0]); + } else { + /* other problems */ + err(udev, "exec of program '%s' failed\n", argv[0]); + } + _exit(1); + case -1: + err(udev, "fork of '%s' failed: %m\n", argv[0]); + return -1; + default: + /* read from child if requested */ + if (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) { + ssize_t count; + size_t respos = 0; + + /* parent closes child ends of pipes */ + if (outpipe[WRITE_END] > 0) + close(outpipe[WRITE_END]); + if (errpipe[WRITE_END] > 0) + close(errpipe[WRITE_END]); + + /* read child output */ + while (outpipe[READ_END] > 0 || errpipe[READ_END] > 0) { + int fdcount; + fd_set readfds; + + FD_ZERO(&readfds); + if (outpipe[READ_END] > 0) + FD_SET(outpipe[READ_END], &readfds); + if (errpipe[READ_END] > 0) + FD_SET(errpipe[READ_END], &readfds); + fdcount = select(UDEV_MAX(outpipe[READ_END], errpipe[READ_END])+1, &readfds, NULL, NULL, NULL); + if (fdcount < 0) { + if (errno == EINTR) + continue; + err = -1; + break; + } + + /* get stdout */ + if (outpipe[READ_END] > 0 && FD_ISSET(outpipe[READ_END], &readfds)) { + char inbuf[1024]; + char *pos; + char *line; + + count = read(outpipe[READ_END], inbuf, sizeof(inbuf)-1); + if (count <= 0) { + close(outpipe[READ_END]); + outpipe[READ_END] = -1; + if (count < 0) { + err(udev, "stdin read failed: %m\n"); + err = -1; + } + continue; + } + inbuf[count] = '\0'; + + /* store result for rule processing */ + if (result) { + if (respos + count < ressize) { + memcpy(&result[respos], inbuf, count); + respos += count; + } else { + err(udev, "ressize %ld too short\n", (long)ressize); + err = -1; + } + } + pos = inbuf; + while ((line = strsep(&pos, "\n"))) + if (pos || line[0] != '\0') + info(udev, "'%s' (stdout) '%s'\n", argv[0], line); + } + + /* get stderr */ + if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) { + char errbuf[1024]; + char *pos; + char *line; + + count = read(errpipe[READ_END], errbuf, sizeof(errbuf)-1); + if (count <= 0) { + close(errpipe[READ_END]); + errpipe[READ_END] = -1; + if (count < 0) + err(udev, "stderr read failed: %m\n"); + continue; + } + errbuf[count] = '\0'; + pos = errbuf; + while ((line = strsep(&pos, "\n"))) + if (pos || line[0] != '\0') + info(udev, "'%s' (stderr) '%s'\n", argv[0], line); + } + } + if (outpipe[READ_END] > 0) + close(outpipe[READ_END]); + if (errpipe[READ_END] > 0) + close(errpipe[READ_END]); + + /* return the childs stdout string */ + if (result) { + result[respos] = '\0'; + dbg(udev, "result='%s'\n", result); + if (reslen) + *reslen = respos; + } + } + waitpid(pid, &status, 0); + if (WIFEXITED(status)) { + info(udev, "'%s' returned with status %i\n", argv[0], WEXITSTATUS(status)); + if (WEXITSTATUS(status) != 0) + err = -1; + } else { + err(udev, "'%s' abnormal exit\n", argv[0]); + err = -1; + } + } + return err; +} |