/* * Copyright (C) 2003-2013 Kay Sievers <kay@vrfy.org> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <stdlib.h> #include <stdio.h> #include <stddef.h> #include <unistd.h> #include <fcntl.h> #include <errno.h> #include <ctype.h> #include <string.h> #include <time.h> #include <net/if.h> #include <sys/prctl.h> #include <sys/poll.h> #include <sys/epoll.h> #include <sys/wait.h> #include <sys/signalfd.h> #include "udev.h" #include "rtnl-util.h" struct udev_event *udev_event_new(struct udev_device *dev) { struct udev *udev = udev_device_get_udev(dev); struct udev_event *event; event = calloc(1, sizeof(struct udev_event)); if (event == NULL) return NULL; event->dev = dev; event->udev = udev; udev_list_init(udev, &event->run_list, false); udev_list_init(udev, &event->seclabel_list, false); event->fd_signal = -1; event->birth_usec = now(CLOCK_MONOTONIC); event->timeout_usec = 30 * 1000 * 1000; return event; } void udev_event_unref(struct udev_event *event) { if (event == NULL) return; udev_list_cleanup(&event->run_list); udev_list_cleanup(&event->seclabel_list); free(event->program_result); free(event->name); free(event); } size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size) { struct udev_device *dev = event->dev; enum subst_type { SUBST_UNKNOWN, SUBST_DEVNODE, SUBST_ATTR, SUBST_ENV, SUBST_KERNEL, SUBST_KERNEL_NUMBER, SUBST_DRIVER, SUBST_DEVPATH, SUBST_ID, SUBST_MAJOR, SUBST_MINOR, SUBST_RESULT, SUBST_PARENT, SUBST_NAME, SUBST_LINKS, SUBST_ROOT, SUBST_SYS, }; static const struct subst_map { const char *name; const char fmt; enum subst_type type; } map[] = { { .name = "devnode", .fmt = 'N', .type = SUBST_DEVNODE }, { .name = "tempnode", .fmt = 'N', .type = SUBST_DEVNODE }, { .name = "attr", .fmt = 's', .type = SUBST_ATTR }, { .name = "sysfs", .fmt = 's', .type = SUBST_ATTR }, { .name = "env", .fmt = 'E', .type = SUBST_ENV }, { .name = "kernel", .fmt = 'k', .type = SUBST_KERNEL }, { .name = "number", .fmt = 'n', .type = SUBST_KERNEL_NUMBER }, { .name = "driver", .fmt = 'd', .type = SUBST_DRIVER }, { .name = "devpath", .fmt = 'p', .type = SUBST_DEVPATH }, { .name = "id", .fmt = 'b', .type = SUBST_ID }, { .name = "major", .fmt = 'M', .type = SUBST_MAJOR }, { .name = "minor", .fmt = 'm', .type = SUBST_MINOR }, { .name = "result", .fmt = 'c', .type = SUBST_RESULT }, { .name = "parent", .fmt = 'P', .type = SUBST_PARENT }, { .name = "name", .fmt = 'D', .type = SUBST_NAME }, { .name = "links", .fmt = 'L', .type = SUBST_LINKS }, { .name = "root", .fmt = 'r', .type = SUBST_ROOT }, { .name = "sys", .fmt = 'S', .type = SUBST_SYS }, }; const char *from; char *s; size_t l; from = src; s = dest; l = size; for (;;) { enum subst_type type = SUBST_UNKNOWN; char attrbuf[UTIL_PATH_SIZE]; char *attr = NULL; while (from[0] != '\0') { if (from[0] == '$') { /* substitute named variable */ unsigned int i; if (from[1] == '$') { from++; goto copy; } for (i = 0; i < ELEMENTSOF(map); i++) { if (startswith(&from[1], map[i].name)) { type = map[i].type; from += strlen(map[i].name)+1; goto subst; } } } else if (from[0] == '%') { /* substitute format char */ unsigned int i; if (from[1] == '%') { from++; goto copy; } for (i = 0; i < ELEMENTSOF(map); i++) { if (from[1] == map[i].fmt) { type = map[i].type; from += 2; goto subst; } } } copy: /* copy char */ if (l == 0) goto out; s[0] = from[0]; from++; s++; l--; } goto out; subst: /* extract possible $format{attr} */ if (from[0] == '{') { unsigned int i; from++; for (i = 0; from[i] != '}'; i++) { if (from[i] == '\0') { log_error("missing closing brace for format '%s'\n", src); goto out; } } if (i >= sizeof(attrbuf)) goto out; memcpy(attrbuf, from, i); attrbuf[i] = '\0'; from += i+1; attr = attrbuf; } else { attr = NULL; } switch (type) { case SUBST_DEVPATH: l = strpcpy(&s, l, udev_device_get_devpath(dev)); break; case SUBST_KERNEL: l = strpcpy(&s, l, udev_device_get_sysname(dev)); break; case SUBST_KERNEL_NUMBER: if (udev_device_get_sysnum(dev) == NULL) break; l = strpcpy(&s, l, udev_device_get_sysnum(dev)); break; case SUBST_ID: if (event->dev_parent == NULL) break; l = strpcpy(&s, l, udev_device_get_sysname(event->dev_parent)); break; case SUBST_DRIVER: { const char *driver; if (event->dev_parent == NULL) break; driver = udev_device_get_driver(event->dev_parent); if (driver == NULL) break; l = strpcpy(&s, l, driver); break; } case SUBST_MAJOR: { char num[UTIL_PATH_SIZE]; sprintf(num, "%d", major(udev_device_get_devnum(dev))); l = strpcpy(&s, l, num); break; } case SUBST_MINOR: { char num[UTIL_PATH_SIZE]; sprintf(num, "%d", minor(udev_device_get_devnum(dev))); l = strpcpy(&s, l, num); break; } case SUBST_RESULT: { char *rest; int i; if (event->program_result == NULL) break; /* get part part of the result string */ i = 0; if (attr != NULL) i = strtoul(attr, &rest, 10); if (i > 0) { char result[UTIL_PATH_SIZE]; char tmp[UTIL_PATH_SIZE]; char *cpos; strscpy(result, sizeof(result), event->program_result); cpos = result; while (--i) { while (cpos[0] != '\0' && !isspace(cpos[0])) cpos++; while (isspace(cpos[0])) cpos++; } if (i > 0) { log_error("requested part of result string not found\n"); break; } strscpy(tmp, sizeof(tmp), cpos); /* %{2+}c copies the whole string from the second part on */ if (rest[0] != '+') { cpos = strchr(tmp, ' '); if (cpos) cpos[0] = '\0'; } l = strpcpy(&s, l, tmp); } else { l = strpcpy(&s, l, event->program_result); } break; } case SUBST_ATTR: { const char *value = NULL; char vbuf[UTIL_NAME_SIZE]; size_t len; int count; if (attr == NULL) { log_error("missing file parameter for attr\n"); break; } /* try to read the value specified by "[dmi/id]product_name" */ if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0) value = vbuf; /* try to read the attribute the device */ if (value == NULL) value = udev_device_get_sysattr_value(event->dev, attr); /* try to read the attribute of the parent device, other matches have selected */ if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev) value = udev_device_get_sysattr_value(event->dev_parent, attr); if (value == NULL) break; /* strip trailing whitespace, and replace unwanted characters */ if (value != vbuf) strscpy(vbuf, sizeof(vbuf), value); len = strlen(vbuf); while (len > 0 && isspace(vbuf[--len])) vbuf[len] = '\0'; count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT); if (count > 0) log_debug("%i character(s) replaced\n" , count); l = strpcpy(&s, l, vbuf); break; } case SUBST_PARENT: { struct udev_device *dev_parent; const char *devnode; dev_parent = udev_device_get_parent(event->dev); if (dev_parent == NULL) break; devnode = udev_device_get_devnode(dev_parent); if (devnode != NULL) l = strpcpy(&s, l, devnode + strlen("/dev/")); break; } case SUBST_DEVNODE: if (udev_device_get_devnode(dev) != NULL) l = strpcpy(&s, l, udev_device_get_devnode(dev)); break; case SUBST_NAME: if (event->name != NULL) l = strpcpy(&s, l, event->name); else if (udev_device_get_devnode(dev) != NULL) l = strpcpy(&s, l, udev_device_get_devnode(dev) + strlen("/dev/")); else l = strpcpy(&s, l, udev_device_get_sysname(dev)); break; case SUBST_LINKS: { struct udev_list_entry *list_entry; list_entry = udev_device_get_devlinks_list_entry(dev); if (list_entry == NULL) break; l = strpcpy(&s, l, udev_list_entry_get_name(list_entry) + strlen("/dev/")); udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry)) l = strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry) + strlen("/dev/"), NULL); break; } case SUBST_ROOT: l = strpcpy(&s, l, "/dev"); break; case SUBST_SYS: l = strpcpy(&s, l, "/sys"); break; case SUBST_ENV: if (attr == NULL) { break; } else { const char *value; value = udev_device_get_property_value(event->dev, attr); if (value == NULL) break; l = strpcpy(&s, l, value); break; } default: log_error("unknown substitution type=%i\n", type); break; } } out: s[0] = '\0'; return l; } static int spawn_exec(struct udev_event *event, const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask, int fd_stdout, int fd_stderr) { 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 { log_error("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; log_error("failed to execute '%s' '%s': %m\n", argv[0], cmd); return err; } static void spawn_read(struct udev_event *event, const char *cmd, int fd_stdout, int fd_stderr, char *result, size_t ressize) { size_t respos = 0; int fd_ep = -1; struct epoll_event ep_outpipe, ep_errpipe; /* read from child if requested */ if (fd_stdout < 0 && fd_stderr < 0) return; fd_ep = epoll_create1(EPOLL_CLOEXEC); if (fd_ep < 0) { log_error("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) { log_error("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) { log_error("fail to add fd to epoll: %m\n"); goto out; } } /* read child output */ while (fd_stdout >= 0 || fd_stderr >= 0) { int timeout; int fdcount; struct epoll_event ev[4]; int i; if (event->timeout_usec > 0) { usec_t age_usec; age_usec = now(CLOCK_MONOTONIC) - event->birth_usec; if (age_usec >= event->timeout_usec) { log_error("timeout '%s'\n", cmd); goto out; } timeout = ((event->timeout_usec - age_usec) / 1000) + 1000; } else { timeout = -1; } fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout); if (fdcount < 0) { if (errno == EINTR) continue; log_error("failed to poll: %m\n"); goto out; } if (fdcount == 0) { log_error("timeout '%s'\n", cmd); 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 { log_error("'%s' ressize %zd too short\n", cmd, ressize); } } /* 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') log_debug("'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line); } } } else if (ev[i].events & EPOLLHUP) { if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) { log_error("failed to remove fd from epoll: %m\n"); goto out; } *fd = -1; } } } /* return the child's stdout string */ if (result != NULL) result[respos] = '\0'; out: if (fd_ep >= 0) close(fd_ep); } static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid) { struct pollfd pfd[1]; int err = 0; pfd[0].events = POLLIN; pfd[0].fd = event->fd_signal; while (pid > 0) { int timeout; int fdcount; if (event->timeout_usec > 0) { usec_t age_usec; age_usec = now(CLOCK_MONOTONIC) - event->birth_usec; if (age_usec >= event->timeout_usec) timeout = 1000; else timeout = ((event->timeout_usec - age_usec) / 1000) + 1000; } else { timeout = -1; } fdcount = poll(pfd, 1, timeout); if (fdcount < 0) { if (errno == EINTR) continue; err = -errno; log_error("failed to poll: %m\n"); goto out; } if (fdcount == 0) { log_error("timeout: killing '%s' [%u]\n", cmd, pid); kill(pid, SIGKILL); } if (pfd[0].revents & POLLIN) { struct signalfd_siginfo fdsi; int status; ssize_t size; size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo)); if (size != sizeof(struct signalfd_siginfo)) continue; switch (fdsi.ssi_signo) { case SIGTERM: event->sigterm = true; break; case SIGCHLD: if (waitpid(pid, &status, WNOHANG) < 0) break; if (WIFEXITED(status)) { log_debug("'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status)); if (WEXITSTATUS(status) != 0) err = -1; } else if (WIFSIGNALED(status)) { log_error("'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status))); err = -1; } else if (WIFSTOPPED(status)) { log_error("'%s' [%u] stopped\n", cmd, pid); err = -1; } else if (WIFCONTINUED(status)) { log_error("'%s' [%u] continued\n", cmd, pid); err = -1; } else { log_error("'%s' [%u] exit with status 0x%04x\n", cmd, pid, status); err = -1; } pid = 0; break; } } } out: return err; } int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[]) { int i = 0; char *pos; if (strchr(cmd, ' ') == NULL) { argv[i++] = cmd; goto out; } pos = cmd; while (pos != NULL && pos[0] != '\0') { if (pos[0] == '\'') { /* do not separate quotes */ pos++; argv[i] = strsep(&pos, "\'"); if (pos != NULL) while (pos[0] == ' ') pos++; } else { argv[i] = strsep(&pos, " "); if (pos != NULL) while (pos[0] == ' ') pos++; } i++; } out: argv[i] = NULL; if (argc) *argc = i; return 0; } int udev_event_spawn(struct udev_event *event, const char *cmd, char **envp, const sigset_t *sigmask, char *result, size_t ressize) { struct udev *udev = event->udev; int outpipe[2] = {-1, -1}; int errpipe[2] = {-1, -1}; pid_t pid; char arg[UTIL_PATH_SIZE]; char *argv[128]; char program[UTIL_PATH_SIZE]; int err = 0; strscpy(arg, sizeof(arg), cmd); udev_build_argv(event->udev, arg, NULL, argv); /* pipes from child to parent */ if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) { if (pipe2(outpipe, O_NONBLOCK) != 0) { err = -errno; log_error("pipe failed: %m\n"); goto out; } } if (udev_get_log_priority(udev) >= LOG_INFO) { if (pipe2(errpipe, O_NONBLOCK) != 0) { err = -errno; log_error("pipe failed: %m\n"); goto out; } } /* allow programs in /usr/lib/udev/ to be called without the path */ if (argv[0][0] != '/') { strscpyl(program, sizeof(program), UDEVLIBEXECDIR "/", argv[0], NULL); argv[0] = program; } pid = fork(); switch(pid) { case 0: /* child closes parent's ends of pipes */ if (outpipe[READ_END] >= 0) { close(outpipe[READ_END]); outpipe[READ_END] = -1; } if (errpipe[READ_END] >= 0) { close(errpipe[READ_END]); errpipe[READ_END] = -1; } log_debug("starting '%s'\n", cmd); spawn_exec(event, cmd, argv, envp, sigmask, outpipe[WRITE_END], errpipe[WRITE_END]); _exit(2 ); case -1: log_error("fork of '%s' failed: %m\n", cmd); err = -1; goto out; default: /* 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; } spawn_read(event, cmd, outpipe[READ_END], errpipe[READ_END], result, ressize); err = spawn_wait(event, cmd, pid); } 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; } static int rename_netif(struct udev_event *event) { struct udev_device *dev = event->dev; _cleanup_sd_rtnl_unref_ sd_rtnl *rtnl = NULL; char name[IFNAMSIZ]; const char *oldname; int r; oldname = udev_device_get_sysname(dev); log_debug("changing net interface name from '%s' to '%s'\n", oldname, event->name); strscpy(name, IFNAMSIZ, event->name); r = sd_rtnl_open(0, &rtnl); if (r < 0) return r; r = rtnl_set_link_name(rtnl, udev_device_get_ifindex(dev), name); if (r < 0) log_error("error changing net interface name %s to %s: %s", oldname, name, strerror(-r)); else print_kmsg("renamed network interface %s to %s", oldname, name); return r; } int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules, const sigset_t *sigmask) { struct udev_device *dev = event->dev; int err = 0; if (udev_device_get_subsystem(dev) == NULL) return -1; if (streq(udev_device_get_action(dev), "remove")) { udev_device_read_db(dev, NULL); udev_device_delete_db(dev); udev_device_tag_index(dev, NULL, false); if (major(udev_device_get_devnum(dev)) != 0) udev_watch_end(event->udev, dev); udev_rules_apply_to_event(rules, event, sigmask); if (major(udev_device_get_devnum(dev)) != 0) udev_node_remove(dev); } else { event->dev_db = udev_device_new(event->udev); if (event->dev_db != NULL) { udev_device_set_syspath(event->dev_db, udev_device_get_syspath(dev)); udev_device_set_subsystem(event->dev_db, udev_device_get_subsystem(dev)); udev_device_read_db(event->dev_db, NULL); udev_device_set_info_loaded(event->dev_db); /* disable watch during event processing */ if (major(udev_device_get_devnum(dev)) != 0) udev_watch_end(event->udev, event->dev_db); } udev_rules_apply_to_event(rules, event, sigmask); /* rename a new network interface, if needed */ if (udev_device_get_ifindex(dev) > 0 && streq(udev_device_get_action(dev), "add") && event->name != NULL && !streq(event->name, udev_device_get_sysname(dev))) { char syspath[UTIL_PATH_SIZE]; char *pos; err = rename_netif(event); if (err == 0) { log_debug("renamed netif to '%s'\n", event->name); /* remember old name */ udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev)); /* now change the devpath, because the kernel device name has changed */ strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev)); pos = strrchr(syspath, '/'); if (pos != NULL) { pos++; strscpy(pos, sizeof(syspath) - (pos - syspath), event->name); udev_device_set_syspath(event->dev, syspath); udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev)); log_debug("changed devpath to '%s'\n", udev_device_get_devpath(dev)); } } } if (major(udev_device_get_devnum(dev)) > 0) { bool apply; /* remove/update possible left-over symlinks from old database entry */ if (event->dev_db != NULL) udev_node_update_old_links(dev, event->dev_db); if (!event->owner_set) event->uid = udev_device_get_devnode_uid(dev); if (!event->group_set) event->gid = udev_device_get_devnode_gid(dev); if (!event->mode_set) { if (udev_device_get_devnode_mode(dev) > 0) { /* kernel supplied value */ event->mode = udev_device_get_devnode_mode(dev); } else if (event->gid > 0) { /* default 0660 if a group is assigned */ event->mode = 0660; } else { /* default 0600 */ event->mode = 0600; } } apply = streq(udev_device_get_action(dev), "add") || event->owner_set || event->group_set || event->mode_set; udev_node_add(dev, apply, event->mode, event->uid, event->gid, &event->seclabel_list); } /* preserve old, or get new initialization timestamp */ if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0) udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db)); else if (udev_device_get_usec_initialized(event->dev) == 0) udev_device_set_usec_initialized(event->dev, now(CLOCK_MONOTONIC)); /* (re)write database file */ udev_device_update_db(dev); udev_device_tag_index(dev, event->dev_db, true); udev_device_set_is_initialized(dev); udev_device_unref(event->dev_db); event->dev_db = NULL; } return err; } void udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask) { struct udev_list_entry *list_entry; udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) { const char *cmd = udev_list_entry_get_name(list_entry); enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry); if (builtin_cmd < UDEV_BUILTIN_MAX) { char command[UTIL_PATH_SIZE]; udev_event_apply_format(event, cmd, command, sizeof(command)); udev_builtin_run(event->dev, builtin_cmd, command, false); } else { char program[UTIL_PATH_SIZE]; char **envp; if (event->exec_delay > 0) { log_debug("delay execution of '%s'\n", program); sleep(event->exec_delay); } udev_event_apply_format(event, cmd, program, sizeof(program)); envp = udev_device_get_properties_envp(event->dev); udev_event_spawn(event, program, envp, sigmask, NULL, 0); } } }