service/trigger.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <sys/stat.h>
  16 #include <sys/socket.h>
  17 #include <sys/types.h>
  18
  19 #include <linux/types.h>
  20 #include <linux/netlink.h>
  21
  22 #include <libubox/blobmsg_json.h>
  23 #include <libubox/json_script.h>
  24 #include <libubox/runqueue.h>
  25 #include <libubox/ustream.h>
  26 #include <libubox/uloop.h>
  27
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <libgen.h>
  32
  33 #include "../procd.h"
  34
  35 struct trigger {
  36         struct list_head list;
  37
  38         char *type;
  39
  40         int pending;
  41         int remove;
  42         int timeout;
  43
  44         void *id;
  45
  46         struct blob_attr *rule;
  47         struct blob_attr *data;
  48         struct uloop_timeout delay;
  49
  50         struct json_script_ctx jctx;
  51 };
  52
  53 struct job;
  54 struct cmd {
  55         char *name;
  56         void (*handler)(struct job *job, struct blob_attr *exec, struct blob_attr *env);
  57 };
  58
  59 struct job {
  60         struct runqueue_process proc;
  61         struct cmd *cmd;
  62         struct trigger *trigger;
  63         struct blob_attr *exec;
  64         struct blob_attr *env;
  65 };
  66
  67 static LIST_HEAD(triggers);
  68 static struct runqueue q;
  69
  70 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
  71 {
  72         return NULL;
  73 }
  74
  75 static struct json_script_file *
  76 rule_load_script(struct json_script_ctx *ctx, const char *name)
  77 {
  78         struct trigger *t = container_of(ctx, struct trigger, jctx);
  79
  80         return json_script_file_from_blobmsg(t->type, t->rule, blob_pad_len(t->rule));
  81 }
  82
  83 static void q_job_run(struct runqueue *q, struct runqueue_task *t)
  84 {
  85         struct job *j = container_of(t, struct job, proc.task);
  86
  87         DEBUG(4, "handle event %s\n", j->cmd->name);
  88         j->cmd->handler(j, j->exec, j->env);
  89 }
  90
  91 static void trigger_free(struct trigger *t)
  92 {
  93         json_script_free(&t->jctx);
  94         uloop_timeout_cancel(&t->delay);
  95         free(t->data);
  96         list_del(&t->list);
  97         free(t);
  98 }
  99
 100 static void q_job_complete(struct runqueue *q, struct runqueue_task *p)
 101 {
 102         struct job *j = container_of(p, struct job, proc.task);
 103
 104         if (j->trigger->remove) {
 105                 trigger_free(j->trigger);
 106         } else {
 107                 j->trigger->pending = 0;
 108         }
 109         free(j);
 110 }
 111
 112 static void add_job(struct trigger *t, struct cmd *cmd, struct blob_attr *exec, struct blob_attr *data)
 113 {
 114         static const struct runqueue_task_type job_type = {
 115                 .run = q_job_run,
 116                 .cancel = runqueue_process_cancel_cb,
 117                 .kill = runqueue_process_kill_cb,
 118         };
 119         struct blob_attr *d, *e;
 120         struct job *j = calloc_a(sizeof(*j), &e, blob_pad_len(exec), &d, blob_pad_len(data));
 121
 122         j->env = d;
 123         j->exec = e;
 124         j->cmd = cmd;
 125         j->trigger = t;
 126         j->proc.task.type = &job_type;
 127         j->proc.task.complete = q_job_complete;
 128         t->pending = 1;
 129
 130         memcpy(j->exec, exec, blob_pad_len(exec));
 131         memcpy(j->env, data, blob_pad_len(data));
 132
 133         runqueue_task_add(&q, &j->proc.task, false);
 134 }
 135
 136 static void _setenv(const char *key, const char *val)
 137 {
 138         char _key[32];
 139
 140         snprintf(_key, sizeof(_key), "PARAM_%s", key);
 141         setenv(_key, val, 1);
 142 }
 143
 144 static void handle_run_script(struct job *j, struct blob_attr *exec, struct blob_attr *env)
 145 {
 146         char *argv[8];
 147         struct blob_attr *cur;
 148         int rem;
 149         int i = 0;
 150         pid_t pid;
 151
 152         pid = fork();
 153         if (pid < 0)
 154                 return;
 155
 156         if (pid) {
 157                 runqueue_process_add(&q, &j->proc, pid);
 158                 return;
 159         }
 160
 161         if (debug < 3) {
 162                 close(STDIN_FILENO);
 163                 close(STDOUT_FILENO);
 164                 close(STDERR_FILENO);
 165         }
 166
 167         _setenv("type", j->trigger->type);
 168         blobmsg_for_each_attr(cur, j->env, rem)
 169                 _setenv(blobmsg_name(cur), blobmsg_data(cur));
 170
 171         blobmsg_for_each_attr(cur, j->exec, rem) {
 172                 argv[i] = blobmsg_data(cur);
 173                 i++;
 174                 if (i == 7)
 175                         break;
 176         }
 177
 178         if (i > 0) {
 179                 argv[i] = NULL;
 180                 execvp(argv[0], &argv[0]);
 181         }
 182
 183         exit(1);
 184 }
 185
 186 static struct cmd handlers[] = {
 187         {
 188                 .name = "run_script",
 189                 .handler = handle_run_script,
 190         },
 191 };
 192
 193 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 194                                 struct blob_attr *exec, struct blob_attr *vars)
 195 {
 196         struct trigger *t = container_of(ctx, struct trigger, jctx);
 197         int i;
 198
 199         if (t->pending)
 200                 return;
 201
 202         for (i = 0; i < ARRAY_SIZE(handlers); i++) {
 203                 if (!strcmp(handlers[i].name, name)) {
 204                         add_job(t, &handlers[i], exec, vars);
 205                         break;
 206                 }
 207         }
 208 }
 209
 210 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 211                                 struct blob_attr *context)
 212 {
 213         char *s;
 214
 215         s = blobmsg_format_json(context, false);
 216         ERROR("ERROR: %s in block: %s\n", msg, s);
 217         free(s);
 218 }
 219
 220 static void q_empty(struct runqueue *q)
 221 {
 222 }
 223
 224 static void trigger_delay_cb(struct uloop_timeout *tout)
 225 {
 226         struct trigger *t = container_of(tout, struct trigger, delay);
 227
 228         json_script_run(&t->jctx, "foo", t->data);
 229         free(t->data);
 230         t->data = NULL;
 231 }
 232
 233 static struct trigger* _trigger_add(char *type, struct blob_attr *rule, int timeout, void *id)
 234 {
 235         char *_t;
 236         struct blob_attr *_r;
 237         struct trigger *t = calloc_a(sizeof(*t), &_t, strlen(type) + 1, &_r, blob_pad_len(rule));
 238
 239         t->type = _t;
 240         t->rule = _r;
 241         t->delay.cb = trigger_delay_cb;
 242         t->timeout = timeout;
 243         t->pending = 0;
 244         t->remove = 0;
 245         t->id = id;
 246         t->jctx.handle_var = rule_handle_var,
 247         t->jctx.handle_error = rule_handle_error,
 248         t->jctx.handle_command = rule_handle_command,
 249         t->jctx.handle_file = rule_load_script,
 250
 251         strcpy(t->type, type);
 252         memcpy(t->rule, rule, blob_pad_len(rule));
 253
 254         list_add(&t->list, &triggers);
 255         json_script_init(&t->jctx);
 256
 257         return t;
 258 }
 259
 260 void trigger_add(struct blob_attr *rule, void *id)
 261 {
 262         struct blob_attr *cur;
 263         int rem;
 264
 265         blobmsg_for_each_attr(cur, rule, rem) {
 266                 struct blob_attr *_cur, *type = NULL, *script = NULL, *timeout = NULL;
 267                 int _rem;
 268                 int i = 0;
 269
 270                 if (blobmsg_type(cur) != BLOBMSG_TYPE_ARRAY)
 271                         continue;
 272
 273                 blobmsg_for_each_attr(_cur, cur, _rem) {
 274                         switch (i++) {
 275                         case 0:
 276                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_STRING)
 277                                         type = _cur;
 278                                 break;
 279
 280                         case 1:
 281                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_ARRAY)
 282                                         script = _cur;
 283                                 break;
 284
 285                         case 2:
 286                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_INT32)
 287                                         timeout = _cur;
 288                                 break;
 289                         }
 290                 }
 291
 292                 if (type && script) {
 293                         int t = 0;
 294
 295                         if (timeout)
 296                                 t = blobmsg_get_u32(timeout);
 297                         _trigger_add(blobmsg_get_string(type), script, t, id);
 298                 }
 299         }
 300 }
 301
 302 void trigger_del(void *id)
 303 {
 304         struct trigger *t, *n;
 305
 306         list_for_each_entry_safe(t, n, &triggers, list) {
 307                 if (t->id != id)
 308                         continue;
 309
 310                 if (t->pending) {
 311                         t->remove = 1;
 312                         continue;
 313                 }
 314
 315                 trigger_free(t);
 316         }
 317 }
 318
 319 void trigger_init(void)
 320 {
 321         runqueue_init(&q);
 322         q.empty_cb = q_empty;
 323         q.max_running_tasks = 1;
 324 }
 325
 326 static bool trigger_match(const char *event, const char *match)
 327 {
 328         char *wildcard = strstr(match, ".*");
 329         if (wildcard)
 330                 return !strncmp(event, match, wildcard - match);
 331         return !strcmp(event, match);
 332 }
 333
 334 void trigger_event(const char *type, struct blob_attr *data)
 335 {
 336         struct trigger *t;
 337
 338         list_for_each_entry(t, &triggers, list) {
 339                 if (t->remove)
 340                         continue;
 341                 if (trigger_match(type, t->type)) {
 342                         if (t->timeout) {
 343                                 free(t->data);
 344                                 t->data = blob_memdup(data);
 345                                 uloop_timeout_set(&t->delay, t->timeout);
 346                         } else {
 347                                 json_script_run(&t->jctx, "foo", data);
 348                         }
 349                 }
 350         }
 351 }