/* SPDX-License-Identifier: GPL-2.0+ */ /* * */ #include #include #include #include #include #include #include #include #include #include "fd-util.h" #include "format-util.h" #include "udev-util.h" #include "udev.h" #include "udevadm-util.h" static bool udev_exit; static void sig_handler(int signum) { if (IN_SET(signum, SIGINT, SIGTERM)) udev_exit = true; } static void print_device(struct udev_device *device, const char *source, int prop) { struct timespec ts; 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, udev_device_get_action(device), udev_device_get_devpath(device), udev_device_get_subsystem(device)); if (prop) { struct udev_list_entry *list_entry; udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(device)) printf("%s=%s\n", udev_list_entry_get_name(list_entry), udev_list_entry_get_value(list_entry)); printf("\n"); } } static void 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); } static int adm_monitor(struct udev *udev, int argc, char *argv[]) { struct sigaction act = {}; sigset_t mask; bool prop = false; bool print_kernel = false; bool print_udev = false; _cleanup_(udev_list_cleanup) struct udev_list subsystem_match_list; _cleanup_(udev_list_cleanup) struct udev_list tag_match_list; _cleanup_(udev_monitor_unrefp) struct udev_monitor *udev_monitor = NULL; _cleanup_(udev_monitor_unrefp) struct udev_monitor *kernel_monitor = NULL; _cleanup_close_ int fd_ep = -1; int fd_kernel = -1, fd_udev = -1; struct epoll_event ep_kernel, ep_udev; int c; 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' }, {} }; udev_list_init(udev, &subsystem_match_list, true); udev_list_init(udev, &tag_match_list, true); while ((c = getopt_long(argc, argv, "pekus:t:Vh", options, NULL)) >= 0) switch (c) { case 'p': case 'e': prop = true; break; case 'k': print_kernel = true; break; case 'u': print_udev = true; break; case 's': { char subsys[UTIL_NAME_SIZE]; char *devtype; strscpy(subsys, sizeof(subsys), optarg); devtype = strchr(subsys, '/'); if (devtype != NULL) { devtype[0] = '\0'; devtype++; } udev_list_entry_add(&subsystem_match_list, subsys, devtype); break; } case 't': udev_list_entry_add(&tag_match_list, optarg, NULL); break; case 'V': print_version(); return 0; case 'h': help(); return 0; default: return 1; } if (!print_kernel && !print_udev) { print_kernel = true; print_udev = true; } /* set signal handlers */ act.sa_handler = sig_handler; act.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) { log_error_errno(errno, "error creating epoll fd: %m"); return 1; } printf("monitor will print the received events for:\n"); if (print_udev) { struct udev_list_entry *entry; udev_monitor = udev_monitor_new_from_netlink(udev, "udev"); if (udev_monitor == NULL) { fprintf(stderr, "error: unable to create netlink socket\n"); return 1; } udev_monitor_set_receive_buffer_size(udev_monitor, 128*1024*1024); fd_udev = udev_monitor_get_fd(udev_monitor); udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) { const char *subsys = udev_list_entry_get_name(entry); const char *devtype = udev_list_entry_get_value(entry); if (udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, subsys, devtype) < 0) fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys); } udev_list_entry_foreach(entry, udev_list_get_entry(&tag_match_list)) { const char *tag = udev_list_entry_get_name(entry); if (udev_monitor_filter_add_match_tag(udev_monitor, tag) < 0) fprintf(stderr, "error: unable to apply tag filter '%s'\n", tag); } if (udev_monitor_enable_receiving(udev_monitor) < 0) { fprintf(stderr, "error: unable to subscribe to udev events\n"); return 2; } memzero(&ep_udev, sizeof(struct epoll_event)); ep_udev.events = EPOLLIN; ep_udev.data.fd = fd_udev; if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0) { log_error_errno(errno, "fail to add fd to epoll: %m"); return 2; } printf("UDEV - the event which udev sends out after rule processing\n"); } if (print_kernel) { struct udev_list_entry *entry; kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel"); if (kernel_monitor == NULL) { fprintf(stderr, "error: unable to create netlink socket\n"); return 3; } udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024); fd_kernel = udev_monitor_get_fd(kernel_monitor); udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) { const char *subsys = udev_list_entry_get_name(entry); if (udev_monitor_filter_add_match_subsystem_devtype(kernel_monitor, subsys, NULL) < 0) fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys); } if (udev_monitor_enable_receiving(kernel_monitor) < 0) { fprintf(stderr, "error: unable to subscribe to kernel events\n"); return 4; } memzero(&ep_kernel, sizeof(struct epoll_event)); ep_kernel.events = EPOLLIN; ep_kernel.data.fd = fd_kernel; if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_kernel, &ep_kernel) < 0) { log_error_errno(errno, "fail to add fd to epoll: %m"); return 5; } printf("KERNEL - the kernel uevent\n"); } printf("\n"); while (!udev_exit) { int fdcount; struct epoll_event ev[4]; int i; fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1); if (fdcount < 0) { if (errno != EINTR) fprintf(stderr, "error receiving uevent message: %m\n"); continue; } for (i = 0; i < fdcount; i++) { if (ev[i].data.fd == fd_kernel && ev[i].events & EPOLLIN) { struct udev_device *device; device = udev_monitor_receive_device(kernel_monitor); if (device == NULL) continue; print_device(device, "KERNEL", prop); udev_device_unref(device); } else if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) { struct udev_device *device; device = udev_monitor_receive_device(udev_monitor); if (device == NULL) continue; print_device(device, "UDEV", prop); udev_device_unref(device); } } } return 0; } const struct udevadm_cmd udevadm_monitor = { .name = "monitor", .cmd = adm_monitor, .help = "Listen to kernel and udev events", };