LXR busybox/util-linux/acpid.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * simple ACPI events listener
   4 *
   5 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
   6 *
   7 * Licensed under GPLv2, see file LICENSE in this source tree.
   8 */
   9//config:config ACPID
  10//config:       bool "acpid (9 kb)"
  11//config:       default y
  12//config:       help
  13//config:       acpid listens to ACPI events coming either in textual form from
  14//config:       /proc/acpi/event (though it is marked deprecated it is still widely
  15//config:       used and _is_ a standard) or in binary form from specified evdevs
  16//config:       (just use /dev/input/event*).
  17//config:
  18//config:       It parses the event to retrieve ACTION and a possible PARAMETER.
  19//config:       It then spawns /etc/acpi/<ACTION>[/<PARAMETER>] either via run-parts
  20//config:       (if the resulting path is a directory) or directly as an executable.
  21//config:
  22//config:       N.B. acpid relies on run-parts so have the latter installed.
  23//config:
  24//config:config FEATURE_ACPID_COMPAT
  25//config:       bool "Accept and ignore redundant options"
  26//config:       default y
  27//config:       depends on ACPID
  28//config:       help
  29//config:       Accept and ignore compatibility options -g -m -s -S -v.
  30
  31//applet:IF_ACPID(APPLET(acpid, BB_DIR_SBIN, BB_SUID_DROP))
  32
  33//kbuild:lib-$(CONFIG_ACPID) += acpid.o
  34
  35//usage:#define acpid_trivial_usage
  36//usage:       "[-df] [-c CONFDIR] [-l LOGFILE] [-a ACTIONFILE] [-M MAPFILE] [-e PROC_EVENT_FILE] [-p PIDFILE]"
  37//usage:#define acpid_full_usage "\n\n"
  38//usage:       "Listen to ACPI events and spawn specific helpers on event arrival\n"
  39//usage:     "\n        -d      Log to stderr, not log file (implies -f)"
  40//usage:     "\n        -f      Run in foreground"
  41//usage:     "\n        -c DIR  Config directory [/etc/acpi]"
  42//usage:     "\n        -e FILE /proc event file [/proc/acpi/event]"
  43//usage:     "\n        -l FILE Log file [/var/log/acpid.log]"
  44//usage:        IF_FEATURE_PIDFILE(
  45//usage:     "\n        -p FILE Pid file [" CONFIG_PID_FILE_PATH "/acpid.pid]"
  46//usage:        )
  47//usage:     "\n        -a FILE Action file [/etc/acpid.conf]"
  48//usage:     "\n        -M FILE Map file [/etc/acpi.map]"
  49//usage:        IF_FEATURE_ACPID_COMPAT(
  50//usage:     "\n\nAccept and ignore compatibility options -g -m -s -S -v"
  51//usage:        )
  52//usage:
  53//usage:#define acpid_example_usage
  54//usage:       "Without -e option, acpid uses all /dev/input/event* files\n"
  55//usage:       "# acpid\n"
  56//usage:       "# acpid -l /var/log/my-acpi-log\n"
  57//usage:       "# acpid -e /proc/acpi/event\n"
  58
  59#include "libbb.h"
  60#include <syslog.h>
  61#include <linux/input.h>
  62
  63#ifndef EV_SW
  64# define EV_SW         0x05
  65#endif
  66#ifndef EV_KEY
  67# define EV_KEY        0x01
  68#endif
  69#ifndef SW_LID
  70# define SW_LID        0x00
  71#endif
  72#ifndef SW_RFKILL_ALL
  73# define SW_RFKILL_ALL 0x03
  74#endif
  75#ifndef KEY_POWER
  76# define KEY_POWER      116     /* SC System Power Down */
  77#endif
  78#ifndef KEY_SLEEP
  79# define KEY_SLEEP      142     /* SC System Sleep */
  80#endif
  81
  82enum {
  83        OPT_c = (1 << 0),
  84        OPT_d = (1 << 1),
  85        OPT_e = (1 << 2),
  86        OPT_f = (1 << 3),
  87        OPT_l = (1 << 4),
  88        OPT_a = (1 << 5),
  89        OPT_M = (1 << 6),
  90        OPT_p = (1 << 7) * ENABLE_FEATURE_PIDFILE,
  91};
  92
  93struct acpi_event {
  94        const char *s_type;
  95        uint16_t n_type;
  96        const char *s_code;
  97        uint16_t n_code;
  98        uint32_t value;
  99        const char *desc;
 100};
 101
 102static const struct acpi_event f_evt_tab[] ALIGN_PTR = {
 103        { "EV_KEY", 0x01, "KEY_POWER", 116, 1, "button/power PWRF 00000080" },
 104        { "EV_KEY", 0x01, "KEY_POWER", 116, 1, "button/power PWRB 00000080" },
 105        { "EV_SW", 0x05, "SW_LID", 0x00, 1, "button/lid LID0 00000080" },
 106};
 107
 108struct acpi_action {
 109        const char *key;
 110        const char *action;
 111};
 112
 113static const struct acpi_action f_act_tab[] ALIGN_PTR = {
 114        { "PWRF", "PWRF/00000080" },
 115        { "LID0", "LID/00000080" },
 116};
 117
 118struct globals {
 119        struct acpi_action *act_tab;
 120        int n_act;
 121        struct acpi_event *evt_tab;
 122        int n_evt;
 123} FIX_ALIASING;
 124#define G (*ptr_to_globals)
 125#define act_tab         (G.act_tab)
 126#define n_act           (G.n_act  )
 127#define evt_tab         (G.evt_tab)
 128#define n_evt           (G.n_evt  )
 129#define INIT_G() do { \
 130        SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 131} while (0)
 132
 133/*
 134 * acpid listens to ACPI events coming either in textual form
 135 * from /proc/acpi/event (though it is marked deprecated,
 136 * it is still widely used and _is_ a standard) or in binary form
 137 * from specified evdevs (just use /dev/input/event*).
 138 * It parses the event to retrieve ACTION and a possible PARAMETER.
 139 * It then spawns /etc/acpi/<ACTION>[/<PARAMETER>] either via run-parts
 140 * (if the resulting path is a directory) or directly.
 141 * If the resulting path does not exist it logs it via perror
 142 * and continues listening.
 143 */
 144
 145static void process_event(const char *event)
 146{
 147        struct stat st;
 148        char *handler = xasprintf("./%s", event);
 149        const char *args[] = { "run-parts", handler, NULL };
 150
 151        // log the event
 152        bb_simple_error_msg(event);
 153
 154        // spawn handler
 155        // N.B. run-parts would require scripts to have #!/bin/sh
 156        // handler is directory? -> use run-parts
 157        // handler is file? -> run it directly
 158        if (0 == stat(event, &st))
 159                spawn((char **)args + (0==(st.st_mode & S_IFDIR)));
 160        else
 161                bb_simple_perror_msg(event);
 162
 163        free(handler);
 164}
 165
 166static const char *find_action(struct input_event *ev, const char *buf)
 167{
 168        const char *action = NULL;
 169        int i;
 170
 171        // map event
 172        for (i = 0; i < n_evt; i++) {
 173                if (ev) {
 174                        if (ev->type == evt_tab[i].n_type && ev->code == evt_tab[i].n_code && ev->value == evt_tab[i].value) {
 175                                action = evt_tab[i].desc;
 176                                break;
 177                        }
 178                }
 179
 180                if (buf) {
 181                        if (is_prefixed_with(evt_tab[i].desc, buf)) {
 182                                action = evt_tab[i].desc;
 183                                break;
 184                        }
 185                }
 186        }
 187
 188        // get action
 189        if (action) {
 190                for (i = 0; i < n_act; i++) {
 191                        if (strstr(action, act_tab[i].key)) {
 192                                action = act_tab[i].action;
 193                                break;
 194                        }
 195                }
 196        }
 197
 198        return action;
 199}
 200
 201static void parse_conf_file(const char *filename)
 202{
 203        parser_t *parser;
 204        char *tokens[2];
 205
 206        parser = config_open2(filename, fopen_for_read);
 207
 208        if (parser) {
 209                while (config_read(parser, tokens, 2, 2, "# \t", PARSE_NORMAL)) {
 210                        act_tab = xrealloc_vector(act_tab, 1, n_act);
 211                        act_tab[n_act].key = xstrdup(tokens[0]);
 212                        act_tab[n_act].action = xstrdup(tokens[1]);
 213                        n_act++;
 214                }
 215                config_close(parser);
 216        } else {
 217                act_tab = (void*)f_act_tab;
 218                n_act = ARRAY_SIZE(f_act_tab);
 219        }
 220}
 221
 222static void parse_map_file(const char *filename)
 223{
 224        parser_t *parser;
 225        char *tokens[6];
 226
 227        parser = config_open2(filename, fopen_for_read);
 228
 229        if (parser) {
 230                while (config_read(parser, tokens, 6, 6, "# \t", PARSE_NORMAL)) {
 231                        evt_tab = xrealloc_vector(evt_tab, 1, n_evt);
 232                        evt_tab[n_evt].s_type = xstrdup(tokens[0]);
 233                        evt_tab[n_evt].n_type = xstrtou(tokens[1], 16);
 234                        evt_tab[n_evt].s_code = xstrdup(tokens[2]);
 235                        evt_tab[n_evt].n_code = xatou16(tokens[3]);
 236                        evt_tab[n_evt].value = xatoi_positive(tokens[4]);
 237                        evt_tab[n_evt].desc = xstrdup(tokens[5]);
 238                        n_evt++;
 239                }
 240                config_close(parser);
 241        } else {
 242                evt_tab = (void*)f_evt_tab;
 243                n_evt = ARRAY_SIZE(f_evt_tab);
 244        }
 245}
 246
 247/*
 248 * acpid [-c conf_dir] [-r conf_file ] [-a map_file ] [-l log_file] [-e proc_event_file]
 249 */
 250
 251int acpid_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 252int acpid_main(int argc UNUSED_PARAM, char **argv)
 253{
 254        int nfd;
 255        int opts;
 256        struct pollfd *pfd;
 257        const char *opt_dir = "/etc/acpi";
 258        const char *opt_input = "/dev/input/event";
 259        const char *opt_logfile = "/var/log/acpid.log";
 260        const char *opt_action = "/etc/acpid.conf";
 261        const char *opt_map = "/etc/acpi.map";
 262#if ENABLE_FEATURE_PIDFILE
 263        const char *opt_pidfile = CONFIG_PID_FILE_PATH "/acpid.pid";
 264#endif
 265
 266        INIT_G();
 267
 268        opts = getopt32(argv, "^"
 269                "c:de:fl:a:M:"
 270                IF_FEATURE_PIDFILE("p:")
 271                IF_FEATURE_ACPID_COMPAT("g:m:s:S:v")
 272                "\0"
 273                "df:e--e",
 274                &opt_dir, &opt_input, &opt_logfile, &opt_action, &opt_map
 275                IF_FEATURE_PIDFILE(, &opt_pidfile)
 276                IF_FEATURE_ACPID_COMPAT(, NULL, NULL, NULL, NULL)
 277        );
 278
 279        if (!(opts & OPT_f)) {
 280                /* No -f "Foreground", we go to background */
 281                bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
 282        }
 283
 284        if (!(opts & OPT_d)) {
 285                /* No -d "Debug", we log to log file.
 286                 * This includes any output from children.
 287                 */
 288                xmove_fd(xopen(opt_logfile, O_WRONLY | O_CREAT | O_APPEND), STDOUT_FILENO);
 289                xdup2(STDOUT_FILENO, STDERR_FILENO);
 290                /* Also, acpid's messages (but not children) will go to syslog too */
 291                openlog(applet_name, LOG_PID, LOG_DAEMON);
 292                logmode = LOGMODE_SYSLOG | LOGMODE_STDIO;
 293        }
 294        /* else: -d "Debug", log is not redirected */
 295
 296        parse_conf_file(opt_action);
 297        parse_map_file(opt_map);
 298
 299        xchdir(opt_dir);
 300
 301        /* We spawn children but don't wait for them. Prevent zombies: */
 302        bb_signals((1 << SIGCHLD), SIG_IGN);
 303        // If you enable this, (1) explain why, (2)
 304        // make sure while(poll) loop below is still interruptible
 305        // by SIGTERM et al:
 306        //bb_signals(BB_FATAL_SIGS, record_signo);
 307
 308        pfd = NULL;
 309        nfd = 0;
 310        while (1) {
 311                int fd;
 312                char *dev_event;
 313
 314                dev_event = xasprintf((opts & OPT_e) ? "%s" : "%s%u", opt_input, nfd);
 315                fd = open(dev_event, O_RDONLY | O_NONBLOCK);
 316                if (fd < 0) {
 317                        if (nfd == 0)
 318                                bb_simple_perror_msg_and_die(dev_event);
 319                        break;
 320                }
 321                free(dev_event);
 322                pfd = xrealloc_vector(pfd, 1, nfd);
 323                pfd[nfd].fd = fd;
 324                pfd[nfd].events = POLLIN;
 325                nfd++;
 326        }
 327
 328        write_pidfile(opt_pidfile);
 329
 330        while (safe_poll(pfd, nfd, -1) > 0) {
 331                int i;
 332                for (i = 0; i < nfd; i++) {
 333                        const char *event;
 334
 335                        if (!(pfd[i].revents & POLLIN)) {
 336                                if (pfd[i].revents == 0)
 337                                        continue; /* this fd has nothing */
 338
 339                                /* Likely POLLERR, POLLHUP, POLLNVAL.
 340                                 * Do not listen on this fd anymore.
 341                                 */
 342                                close(pfd[i].fd);
 343                                nfd--;
 344                                for (; i < nfd; i++)
 345                                        pfd[i].fd = pfd[i + 1].fd;
 346                                break; /* do poll() again */
 347                        }
 348
 349                        event = NULL;
 350                        if (option_mask32 & OPT_e) {
 351                                char *buf;
 352                                int len;
 353
 354                                buf = xmalloc_reads(pfd[i].fd, NULL);
 355                                /* buf = "button/power PWRB 00000080 00000000" */
 356                                len = strlen(buf) - 9;
 357                                if (len >= 0)
 358                                        buf[len] = '\0';
 359                                event = find_action(NULL, buf);
 360                                free(buf);
 361                        } else {
 362                                struct input_event ev;
 363
 364                                if (sizeof(ev) != full_read(pfd[i].fd, &ev, sizeof(ev)))
 365                                        continue;
 366
 367                                if (ev.value != 1 && ev.value != 0)
 368                                        continue;
 369
 370                                event = find_action(&ev, NULL);
 371                        }
 372                        if (!event)
 373                                continue;
 374                        /* spawn event handler */
 375                        process_event(event);
 376                }
 377        }
 378
 379        if (ENABLE_FEATURE_CLEAN_UP) {
 380                while (nfd--)
 381                        close(pfd[nfd].fd);
 382                free(pfd);
 383        }
 384        remove_pidfile(opt_pidfile);
 385
 386        return EXIT_SUCCESS;
 387}
 388