#include <ctype.h>
#include <pwd.h>
#include <grp.h>
+#include <sys/prctl.h>
+#include <sys/epoll.h>
#include <sys/wait.h>
#include <sys/param.h>
return 0;
}
+static int run_program_exec(struct udev *udev, int fd_stdout, int fd_stderr,
+ char *const argv[], char **envp, const sigset_t *sigmask)
+{
+ int err;
+ int fd;
+
+ /* discard child output or connect to pipe */
+ fd = open("/dev/null", O_RDWR);
+ if (fd >= 0) {
+ dup2(fd, STDIN_FILENO);
+ if (fd_stdout < 0)
+ dup2(fd, STDOUT_FILENO);
+ if (fd_stderr < 0)
+ dup2(fd, STDERR_FILENO);
+ close(fd);
+ } else {
+ err(udev, "open /dev/null failed: %m\n");
+ }
+
+ /* connect pipes to std{out,err} */
+ if (fd_stdout >= 0) {
+ dup2(fd_stdout, STDOUT_FILENO);
+ close(fd_stdout);
+ }
+ if (fd_stderr >= 0) {
+ dup2(fd_stderr, STDERR_FILENO);
+ close(fd_stderr);
+ }
+
+ /* terminate child in case parent goes away */
+ prctl(PR_SET_PDEATHSIG, SIGTERM);
+
+ /* restore original udev sigmask before exec */
+ if (sigmask)
+ sigprocmask(SIG_SETMASK, sigmask, NULL);
+
+ execve(argv[0], argv, envp);
+
+ /* exec failed */
+ err = -errno;
+ if (err == -ENOENT || err == -ENOTDIR) {
+ /* may be on a filesystem 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]);
+ }
+ return err;
+}
+
+static int run_program_read(struct udev *udev, int fd_stdout, int fd_stderr,
+ char *const argv[], char *result, size_t ressize, size_t *reslen)
+{
+ size_t respos = 0;
+ int fd_ep = -1;
+ struct epoll_event ep_outpipe;
+ struct epoll_event ep_errpipe;
+ int err = 0;
+
+ /* read from child if requested */
+ if (fd_stdout < 0 && fd_stderr < 0)
+ return 0;
+
+ fd_ep = epoll_create1(EPOLL_CLOEXEC);
+ if (fd_ep < 0) {
+ err = -errno;
+ err(udev, "error creating epoll fd: %m\n");
+ goto out;
+ }
+
+ if (fd_stdout >= 0) {
+ memset(&ep_outpipe, 0, sizeof(struct epoll_event));
+ ep_outpipe.events = EPOLLIN;
+ ep_outpipe.data.ptr = &fd_stdout;
+ if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
+ err(udev, "fail to add fd to epoll: %m\n");
+ goto out;
+ }
+ }
+
+ if (fd_stderr >= 0) {
+ memset(&ep_errpipe, 0, sizeof(struct epoll_event));
+ ep_errpipe.events = EPOLLIN;
+ ep_errpipe.data.ptr = &fd_stderr;
+ if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
+ err(udev, "fail to add fd to epoll: %m\n");
+ goto out;
+ }
+ }
+
+ /* read child output */
+ while (fd_stdout >= 0 || fd_stderr >= 0) {
+ int fdcount;
+ struct epoll_event ev[4];
+ int i;
+
+ fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
+ if (fdcount < 0) {
+ if (errno == EINTR)
+ continue;
+ err(udev, "failed to poll: %m\n");
+ err = -errno;
+ goto out;
+ }
+
+ for (i = 0; i < fdcount; i++) {
+ int *fd = (int *)ev[i].data.ptr;
+
+ if (ev[i].events & EPOLLIN) {
+ ssize_t count;
+ char buf[4096];
+
+ count = read(*fd, buf, sizeof(buf)-1);
+ if (count <= 0)
+ continue;
+ buf[count] = '\0';
+
+ /* store stdout result */
+ if (result != NULL && *fd == fd_stdout) {
+ if (respos + count < ressize) {
+ memcpy(&result[respos], buf, count);
+ respos += count;
+ } else {
+ err(udev, "ressize %zd too short\n", ressize);
+ err = -ENOBUFS;
+ }
+ }
+
+ /* log debug output only if we watch stderr */
+ if (fd_stderr >= 0) {
+ char *pos;
+ char *line;
+
+ pos = buf;
+ while ((line = strsep(&pos, "\n"))) {
+ if (pos != NULL || line[0] != '\0')
+ info(udev, "'%s'(%s) '%s'\n", argv[0], *fd == fd_stdout ? "out" : "err" , line);
+ }
+ }
+ } else if (ev[i].events & EPOLLHUP) {
+ if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
+ err = -errno;
+ err(udev, "failed to remove fd from epoll: %m\n");
+ goto out;
+ }
+ *fd = -1;
+ }
+ }
+ }
+
+ /* return the child's stdout string */
+ if (result != NULL) {
+ result[respos] = '\0';
+ dbg(udev, "result='%s'\n", result);
+ if (reslen != NULL)
+ *reslen = respos;
+ }
+out:
+ if (fd_ep >= 0)
+ close(fd_ep);
+ return err;
+}
+
int util_run_program(struct udev *udev, const char *command, char **envp,
char *result, size_t ressize, size_t *reslen,
const sigset_t *sigmask)
char arg[UTIL_PATH_SIZE];
char program[UTIL_PATH_SIZE];
char *argv[((sizeof(arg) + 1) / 2) + 1];
- int devnull;
int i;
int err = 0;
argv[1] = NULL;
}
- /* prepare pipes from child to parent */
+ /* pipes from child to parent */
if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
- if (pipe(outpipe) != 0) {
+ if (pipe2(outpipe, O_NONBLOCK) != 0) {
+ err = -errno;
err(udev, "pipe failed: %m\n");
- return -1;
+ goto out;
}
}
if (udev_get_log_priority(udev) >= LOG_INFO) {
- if (pipe(errpipe) != 0) {
+ if (pipe2(errpipe, O_NONBLOCK) != 0) {
+ err = -errno;
err(udev, "pipe failed: %m\n");
- return -1;
+ goto out;
}
}
pid = fork();
switch(pid) {
case 0:
- /* child closes parent ends of pipes */
- if (outpipe[READ_END] > 0)
+ /* child closes parent's 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]);
+ outpipe[READ_END] = -1;
}
- if (errpipe[WRITE_END] > 0) {
- dup2(errpipe[WRITE_END], STDERR_FILENO);
- close(errpipe[WRITE_END]);
+ if (errpipe[READ_END] >= 0) {
+ close(errpipe[READ_END]);
+ errpipe[READ_END] = -1;
}
- if (sigmask)
- sigprocmask(SIG_SETMASK, sigmask, NULL);
+ err = run_program_exec(udev, outpipe[WRITE_END], errpipe[WRITE_END], argv, envp, sigmask);
- execve(argv[0], argv, envp);
- if (errno == ENOENT || errno == ENOTDIR) {
- /* may be on a filesystem 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;
+ err = -1;
+ goto out;
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(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);
- }
+ /* parent closed child's ends of pipes */
+ if (outpipe[WRITE_END] >= 0) {
+ close(outpipe[WRITE_END]);
+ outpipe[WRITE_END] = -1;
+ }
+ if (errpipe[WRITE_END] >= 0) {
+ close(errpipe[WRITE_END]);
+ errpipe[WRITE_END] = -1;
+ }
- /* get stderr */
- if (errpipe[READ_END] > 0 && FD_ISSET(errpipe[READ_END], &readfds)) {
- char errbuf[1024];
- char *pos;
- char *line;
+ err = run_program_read(udev, outpipe[READ_END], errpipe[READ_END], argv, result, ressize, reslen);
- 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 child's 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 exitcode %i\n", command, WEXITSTATUS(status));
err = -1;
}
}
+
+out:
+ if (outpipe[READ_END] >= 0)
+ close(outpipe[READ_END]);
+ if (outpipe[WRITE_END] >= 0)
+ close(outpipe[WRITE_END]);
+ if (errpipe[READ_END] >= 0)
+ close(errpipe[READ_END]);
+ if (errpipe[WRITE_END] >= 0)
+ close(errpipe[WRITE_END]);
return err;
}
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