diff options
| -rw-r--r-- | libudev/libudev-util-private.c | 335 |
1 files changed, 201 insertions, 134 deletions
diff --git a/libudev/libudev-util-private.c b/libudev/libudev-util-private.c index c7ad20eb74..87b9edbc71 100644 --- a/libudev/libudev-util-private.c +++ b/libudev/libudev-util-private.c @@ -19,6 +19,8 @@ #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> @@ -259,6 +261,169 @@ int util_resolve_subsys_kernel(struct udev *udev, const char *string, 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) @@ -270,7 +435,6 @@ int util_run_program(struct udev *udev, const char *command, char **envp, char arg[UTIL_PATH_SIZE]; char program[UTIL_PATH_SIZE]; char *argv[((sizeof(arg) + 1) / 2) + 1]; - int devnull; int i; int err = 0; @@ -305,17 +469,19 @@ int util_run_program(struct udev *udev, const char *command, char **envp, 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; } } @@ -328,145 +494,36 @@ int util_run_program(struct udev *udev, const char *command, char **envp, 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)); @@ -477,5 +534,15 @@ int util_run_program(struct udev *udev, const char *command, char **envp, 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; } |