/* SPDX-License-Identifier: GPL-2.0+ */ #include #include #include #include #include #include #include #include #include #include "libudev.h" #include "sd-device.h" #include "alloc-util.h" #include "device-util.h" #include "fd-util.h" #include "format-util.h" #include "hashmap.h" #include "libudev-private.h" #include "set.h" #include "string-util.h" #include "udevadm.h" static bool udev_exit = false; static bool arg_show_property = false; static bool arg_print_kernel = false; static bool arg_print_udev = false; static Set *arg_tag_filter = NULL; static Hashmap *arg_subsystem_filter = NULL; static void sig_handler(int signum) { if (IN_SET(signum, SIGINT, SIGTERM)) udev_exit = true; } static int receive_and_print_device(struct udev_monitor *monitor, const char *source) { const char *action = NULL, *devpath = NULL, *subsystem = NULL; _cleanup_(sd_device_unrefp) sd_device *device = NULL; struct timespec ts; int r; r = udev_monitor_receive_sd_device(monitor, &device); if (r < 0) return log_debug_errno(r, "Failed to receive device from %s, ignoring: %m", source); (void) sd_device_get_property_value(device, "ACTION", &action); (void) sd_device_get_devpath(device, &devpath); (void) sd_device_get_subsystem(device, &subsystem); assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0); printf("%-6s[%"PRI_TIME".%06"PRI_NSEC"] %-8s %s (%s)\n", source, ts.tv_sec, (nsec_t)ts.tv_nsec/1000, action, devpath, subsystem); if (arg_show_property) { const char *key, *value; FOREACH_DEVICE_PROPERTY(device, key, value) printf("%s=%s\n", key, value); printf("\n"); } return 0; } static int setup_monitor(const char *sender, int fd_epoll, struct udev_monitor **ret) { _cleanup_(udev_monitor_unrefp) struct udev_monitor *monitor = NULL; const char *subsystem, *devtype, *tag; struct epoll_event ep = {}; Iterator i; int fd, r; monitor = udev_monitor_new_from_netlink(NULL, sender); if (!monitor) return log_error_errno(errno, "Failed to create netlink socket: %m"); r = udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024); if (r < 0) return log_error_errno(r, "Failed to set receive buffer size: %m"); fd = udev_monitor_get_fd(monitor); if (fd < 0) return log_error_errno(r, "Failed to get socket fd for monitoring: %m"); HASHMAP_FOREACH_KEY(devtype, subsystem, arg_subsystem_filter, i) { r = udev_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, devtype); if (r < 0) return log_error_errno(r, "Failed to apply subsystem filter '%s%s%s': %m", subsystem, devtype ? "/" : "", strempty(devtype)); } SET_FOREACH(tag, arg_tag_filter, i) { r = udev_monitor_filter_add_match_tag(monitor, tag); if (r < 0) return log_error_errno(r, "Failed to apply tag filter '%s': %m", tag); } r = udev_monitor_enable_receiving(monitor); if (r < 0) return log_error_errno(r, "Failed to subscribe %s events: %m", sender); ep = (struct epoll_event) { .events = EPOLLIN, .data.fd = fd, }; if (epoll_ctl(fd_epoll, EPOLL_CTL_ADD, fd, &ep) < 0) return log_error_errno(errno, "Failed to add fd to epoll: %m"); *ret = TAKE_PTR(monitor); return fd; } static int help(void) { printf("%s monitor [OPTIONS]\n\n" "Listen to kernel and udev events.\n\n" " -h --help Show this help\n" " -V --version Show package version\n" " -p --property Print the event properties\n" " -k --kernel Print kernel uevents\n" " -u --udev Print udev events\n" " -s --subsystem-match=SUBSYSTEM[/DEVTYPE] Filter events by subsystem\n" " -t --tag-match=TAG Filter events by tag\n" , program_invocation_short_name); return 0; } static int parse_argv(int argc, char *argv[]) { static const struct option options[] = { { "property", no_argument, NULL, 'p' }, { "environment", no_argument, NULL, 'e' }, /* alias for -p */ { "kernel", no_argument, NULL, 'k' }, { "udev", no_argument, NULL, 'u' }, { "subsystem-match", required_argument, NULL, 's' }, { "tag-match", required_argument, NULL, 't' }, { "version", no_argument, NULL, 'V' }, { "help", no_argument, NULL, 'h' }, {} }; int r, c; while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0) switch (c) { case 'p': case 'e': arg_show_property = true; break; case 'k': arg_print_kernel = true; break; case 'u': arg_print_udev = true; break; case 's': { _cleanup_free_ char *subsystem = NULL, *devtype = NULL; const char *slash; slash = strchr(optarg, '/'); if (slash) { devtype = strdup(devtype + 1); if (!devtype) return -ENOMEM; subsystem = strndup(optarg, devtype - optarg); } else subsystem = strdup(optarg); if (!subsystem) return -ENOMEM; r = hashmap_ensure_allocated(&arg_subsystem_filter, NULL); if (r < 0) return r; r = hashmap_put(arg_subsystem_filter, subsystem, devtype); if (r < 0) return r; subsystem = devtype = NULL; break; } case 't': { _cleanup_free_ char *tag = NULL; r = set_ensure_allocated(&arg_tag_filter, &string_hash_ops); if (r < 0) return r; tag = strdup(optarg); if (!tag) return -ENOMEM; r = set_put(arg_tag_filter, tag); if (r < 0) return r; tag = NULL; break; } case 'V': return version(); case 'h': return help(); case '?': return -EINVAL; default: assert_not_reached("Unknown option."); } if (!arg_print_kernel && !arg_print_udev) { arg_print_kernel = true; arg_print_udev = true; } return 1; } int monitor_main(int argc, char *argv[], void *userdata) { _cleanup_(udev_monitor_unrefp) struct udev_monitor *kernel_monitor = NULL, *udev_monitor = NULL; int fd_kernel = -1, fd_udev = -1; _cleanup_close_ int fd_ep = -1; struct sigaction act; sigset_t mask; int r; r = parse_argv(argc, argv); if (r <= 0) goto finalize; /* set signal handlers */ act = (struct sigaction) { .sa_handler = sig_handler, .sa_flags = SA_RESTART, }; assert_se(sigaction(SIGINT, &act, NULL) == 0); assert_se(sigaction(SIGTERM, &act, NULL) == 0); assert_se(sigemptyset(&mask) == 0); assert_se(sigaddset(&mask, SIGINT) == 0); assert_se(sigaddset(&mask, SIGTERM) == 0); assert_se(sigprocmask(SIG_UNBLOCK, &mask, NULL) == 0); /* Callers are expecting to see events as they happen: Line buffering */ setlinebuf(stdout); fd_ep = epoll_create1(EPOLL_CLOEXEC); if (fd_ep < 0) { r = log_error_errno(errno, "Failed to create epoll fd: %m"); goto finalize; } printf("monitor will print the received events for:\n"); if (arg_print_udev) { fd_udev = setup_monitor("udev", fd_ep, &udev_monitor); if (fd_udev < 0) { r = fd_udev; goto finalize; } printf("UDEV - the event which udev sends out after rule processing\n"); } if (arg_print_kernel) { fd_kernel = setup_monitor("kernel", fd_ep, &kernel_monitor); if (fd_kernel < 0) { r = fd_kernel; goto finalize; } printf("KERNEL - the kernel uevent\n"); } printf("\n"); while (!udev_exit) { struct epoll_event ev[4]; int fdcount, i; fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1); if (fdcount < 0) { if (errno != EINTR) log_debug_errno(errno, "Failed to receive uevent message, ignoring: %m"); continue; } for (i = 0; i < fdcount; i++) if (ev[i].data.fd == fd_kernel && ev[i].events & EPOLLIN) (void) receive_and_print_device(kernel_monitor, "KERNEL"); else if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) (void) receive_and_print_device(udev_monitor, "UDEV"); } r = 0; finalize: hashmap_free_free_free(arg_subsystem_filter); set_free_free(arg_tag_filter); return r; }