1 /* $OpenBSD: hotplugd.c,v 1.15 2019/04/30 17:05:15 mestre Exp $ */ 2 /* 3 * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 /* 19 * Devices hot plugging daemon. 20 */ 21 22 #include <sys/types.h> 23 #include <sys/device.h> 24 #include <sys/hotplug.h> 25 #include <sys/wait.h> 26 27 #include <err.h> 28 #include <errno.h> 29 #include <fcntl.h> 30 #include <libgen.h> 31 #include <signal.h> 32 #include <stdarg.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <syslog.h> 37 #include <unistd.h> 38 39 #define _PATH_DEV_HOTPLUG "/dev/hotplug" 40 #define _PATH_ETC_HOTPLUG "/etc/hotplug" 41 #define _PATH_ETC_HOTPLUG_ATTACH _PATH_ETC_HOTPLUG "/attach" 42 #define _PATH_ETC_HOTPLUG_DETACH _PATH_ETC_HOTPLUG "/detach" 43 #define _LOG_TAG "hotplugd" 44 #define _LOG_FACILITY LOG_DAEMON 45 #define _LOG_OPT (LOG_NDELAY | LOG_PID) 46 47 volatile sig_atomic_t quit = 0; 48 char *device = _PATH_DEV_HOTPLUG; 49 int devfd = -1; 50 51 void exec_script(const char *, int, char *); 52 53 void sigchild(int); 54 void sigquit(int); 55 __dead void usage(void); 56 57 int 58 main(int argc, char *argv[]) 59 { 60 int ch; 61 struct sigaction sact; 62 struct hotplug_event he; 63 64 while ((ch = getopt(argc, argv, "d:")) != -1) 65 switch (ch) { 66 case 'd': 67 device = optarg; 68 break; 69 case '?': 70 default: 71 usage(); 72 /* NOTREACHED */ 73 } 74 75 argc -= optind; 76 argv += optind; 77 if (argc > 0) 78 usage(); 79 80 if (unveil(device, "r") == -1) 81 err(1, "unveil"); 82 if (unveil(_PATH_ETC_HOTPLUG_ATTACH, "rx") == -1) 83 err(1, "unveil"); 84 if (unveil(_PATH_ETC_HOTPLUG_DETACH, "rx") == -1) 85 err(1, "unveil"); 86 if (pledge("stdio rpath proc exec", NULL) == -1) 87 err(1, "pledge"); 88 89 if ((devfd = open(device, O_RDONLY | O_CLOEXEC)) == -1) 90 err(1, "%s", device); 91 92 bzero(&sact, sizeof(sact)); 93 sigemptyset(&sact.sa_mask); 94 sact.sa_flags = 0; 95 sact.sa_handler = sigquit; 96 sigaction(SIGINT, &sact, NULL); 97 sigaction(SIGQUIT, &sact, NULL); 98 sigaction(SIGTERM, &sact, NULL); 99 sact.sa_handler = SIG_IGN; 100 sigaction(SIGHUP, &sact, NULL); 101 sact.sa_handler = sigchild; 102 sact.sa_flags = SA_NOCLDSTOP; 103 sigaction(SIGCHLD, &sact, NULL); 104 105 openlog(_LOG_TAG, _LOG_OPT, _LOG_FACILITY); 106 if (daemon(0, 0) == -1) 107 err(1, "daemon"); 108 109 syslog(LOG_INFO, "started"); 110 111 while (!quit) { 112 if (read(devfd, &he, sizeof(he)) == -1) { 113 if (errno == EINTR) 114 /* ignore */ 115 continue; 116 syslog(LOG_ERR, "read: %m"); 117 exit(1); 118 } 119 120 switch (he.he_type) { 121 case HOTPLUG_DEVAT: 122 syslog(LOG_INFO, "%s attached, class %d", 123 he.he_devname, he.he_devclass); 124 exec_script(_PATH_ETC_HOTPLUG_ATTACH, he.he_devclass, 125 he.he_devname); 126 break; 127 case HOTPLUG_DEVDT: 128 syslog(LOG_INFO, "%s detached, class %d", 129 he.he_devname, he.he_devclass); 130 exec_script(_PATH_ETC_HOTPLUG_DETACH, he.he_devclass, 131 he.he_devname); 132 break; 133 default: 134 syslog(LOG_NOTICE, "unknown event (0x%x)", he.he_type); 135 } 136 } 137 138 syslog(LOG_INFO, "terminated"); 139 140 closelog(); 141 close(devfd); 142 143 return (0); 144 } 145 146 void 147 exec_script(const char *file, int class, char *name) 148 { 149 char strclass[8]; 150 pid_t pid; 151 152 snprintf(strclass, sizeof(strclass), "%d", class); 153 154 if (access(file, X_OK | R_OK) == -1) { 155 if (errno != ENOENT) 156 syslog(LOG_ERR, "%s: %m", file); 157 return; 158 } 159 160 if ((pid = fork()) == -1) { 161 syslog(LOG_ERR, "fork: %m"); 162 return; 163 } 164 if (pid == 0) { 165 /* child process */ 166 execl(file, basename(file), strclass, name, (char *)NULL); 167 syslog(LOG_ERR, "execl %s: %m", file); 168 _exit(1); 169 /* NOTREACHED */ 170 } 171 } 172 173 /* ARGSUSED */ 174 void 175 sigchild(int signum) 176 { 177 struct syslog_data sdata = SYSLOG_DATA_INIT; 178 int saved_errno, status; 179 pid_t pid; 180 181 saved_errno = errno; 182 183 sdata.log_tag = _LOG_TAG; 184 sdata.log_fac = _LOG_FACILITY; 185 sdata.log_stat = _LOG_OPT; 186 187 while ((pid = waitpid(WAIT_ANY, &status, WNOHANG)) != 0) { 188 if (pid == -1) { 189 if (errno == EINTR) 190 continue; 191 if (errno != ECHILD) 192 syslog_r(LOG_ERR, &sdata, "waitpid: %m"); 193 break; 194 } 195 196 if (WIFEXITED(status)) { 197 if (WEXITSTATUS(status) != 0) { 198 syslog_r(LOG_NOTICE, &sdata, 199 "child exit status: %d", 200 WEXITSTATUS(status)); 201 } 202 } else { 203 syslog_r(LOG_NOTICE, &sdata, 204 "child is terminated abnormally"); 205 } 206 } 207 208 errno = saved_errno; 209 } 210 211 /* ARGSUSED */ 212 void 213 sigquit(int signum) 214 { 215 quit = 1; 216 } 217 218 __dead void 219 usage(void) 220 { 221 extern char *__progname; 222 223 fprintf(stderr, "usage: %s [-d device]\n", __progname); 224 exit(1); 225 } 226