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         free(t->data);
  94         list_del(&t->list);
  95         free(t);
  96 }
  97
  98 static void q_job_complete(struct runqueue *q, struct runqueue_task *p)
  99 {
 100         struct job *j = container_of(p, struct job, proc.task);
 101
 102         if (j->trigger->remove) {
 103                 trigger_free(j->trigger);
 104         } else {
 105                 j->trigger->pending = 0;
 106         }
 107         free(j);
 108 }
 109
 110 static void add_job(struct trigger *t, struct cmd *cmd, struct blob_attr *exec, struct blob_attr *data)
 111 {
 112         static const struct runqueue_task_type job_type = {
 113                 .run = q_job_run,
 114                 .cancel = runqueue_process_cancel_cb,
 115                 .kill = runqueue_process_kill_cb,
 116         };
 117         struct blob_attr *d, *e;
 118         struct job *j = calloc_a(sizeof(*j), &e, blob_pad_len(exec), &d, blob_pad_len(data));
 119
 120         j->env = d;
 121         j->exec = e;
 122         j->cmd = cmd;
 123         j->trigger = t;
 124         j->proc.task.type = &job_type;
 125         j->proc.task.complete = q_job_complete;
 126         t->pending = 1;
 127
 128         memcpy(j->exec, exec, blob_pad_len(exec));
 129         memcpy(j->env, data, blob_pad_len(data));
 130
 131         runqueue_task_add(&q, &j->proc.task, false);
 132 }
 133
 134 static void _setenv(const char *key, const char *val)
 135 {
 136         char _key[32];
 137
 138         snprintf(_key, sizeof(_key), "PARAM_%s", key);
 139         setenv(_key, val, 1);
 140 }
 141
 142 static void handle_run_script(struct job *j, struct blob_attr *exec, struct blob_attr *env)
 143 {
 144         char *argv[8];
 145         struct blob_attr *cur;
 146         int rem;
 147         int i = 0;
 148         pid_t pid;
 149
 150         pid = fork();
 151         if (pid < 0)
 152                 return;
 153
 154         if (pid) {
 155                 runqueue_process_add(&q, &j->proc, pid);
 156                 return;
 157         }
 158
 159         if (debug < 3) {
 160                 close(STDIN_FILENO);
 161                 close(STDOUT_FILENO);
 162                 close(STDERR_FILENO);
 163         }
 164
 165         _setenv("type", j->trigger->type);
 166         blobmsg_for_each_attr(cur, j->env, rem)
 167                 _setenv(blobmsg_name(cur), blobmsg_data(cur));
 168
 169         blobmsg_for_each_attr(cur, j->exec, rem) {
 170                 argv[i] = blobmsg_data(cur);
 171                 i++;
 172                 if (i == 7)
 173                         break;
 174         }
 175
 176         if (i > 0) {
 177                 argv[i] = NULL;
 178                 execvp(argv[0], &argv[0]);
 179         }
 180
 181         exit(1);
 182 }
 183
 184 static struct cmd handlers[] = {
 185         {
 186                 .name = "run_script",
 187                 .handler = handle_run_script,
 188         },
 189 };
 190
 191 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 192                                 struct blob_attr *exec, struct blob_attr *vars)
 193 {
 194         struct trigger *t = container_of(ctx, struct trigger, jctx);
 195         int i;
 196
 197         if (t->pending)
 198                 return;
 199
 200         for (i = 0; i < ARRAY_SIZE(handlers); i++) {
 201                 if (!strcmp(handlers[i].name, name)) {
 202                         add_job(t, &handlers[i], exec, vars);
 203                         break;
 204                 }
 205         }
 206 }
 207
 208 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 209                                 struct blob_attr *context)
 210 {
 211         char *s;
 212
 213         s = blobmsg_format_json(context, false);
 214         ERROR("ERROR: %s in block: %s\n", msg, s);
 215         free(s);
 216 }
 217
 218 static void q_empty(struct runqueue *q)
 219 {
 220 }
 221
 222 static void trigger_delay_cb(struct uloop_timeout *tout)
 223 {
 224         struct trigger *t = container_of(tout, struct trigger, delay);
 225
 226         json_script_run(&t->jctx, "foo", t->data);
 227         free(t->data);
 228         t->data = NULL;
 229 }
 230
 231 static struct trigger* _trigger_add(char *type, struct blob_attr *rule, int timeout, void *id)
 232 {
 233         char *_t;
 234         struct blob_attr *_r;
 235         struct trigger *t = calloc_a(sizeof(*t), &_t, strlen(type) + 1, &_r, blob_pad_len(rule));
 236
 237         t->type = _t;
 238         t->rule = _r;
 239         t->delay.cb = trigger_delay_cb;
 240         t->timeout = timeout;
 241         t->pending = 0;
 242         t->remove = 0;
 243         t->id = id;
 244         t->jctx.handle_var = rule_handle_var,
 245         t->jctx.handle_error = rule_handle_error,
 246         t->jctx.handle_command = rule_handle_command,
 247         t->jctx.handle_file = rule_load_script,
 248
 249         strcpy(t->type, type);
 250         memcpy(t->rule, rule, blob_pad_len(rule));
 251
 252         list_add(&t->list, &triggers);
 253         json_script_init(&t->jctx);
 254
 255         return t;
 256 }
 257
 258 void trigger_add(struct blob_attr *rule, void *id)
 259 {
 260         struct blob_attr *cur;
 261         int rem;
 262
 263         blobmsg_for_each_attr(cur, rule, rem) {
 264                 struct blob_attr *_cur, *type = NULL, *script = NULL, *timeout = NULL;
 265                 int _rem;
 266                 int i = 0;
 267
 268                 if (blobmsg_type(cur) != BLOBMSG_TYPE_ARRAY)
 269                         continue;
 270
 271                 blobmsg_for_each_attr(_cur, cur, _rem) {
 272                         switch (i++) {
 273                         case 0:
 274                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_STRING)
 275                                         type = _cur;
 276                                 break;
 277
 278                         case 1:
 279                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_ARRAY)
 280                                         script = _cur;
 281                                 break;
 282
 283                         case 2:
 284                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_INT32)
 285                                         timeout = _cur;
 286                                 break;
 287                         }
 288                 }
 289
 290                 if (type && script) {
 291                         int t = 0;
 292
 293                         if (timeout)
 294                                 t = blobmsg_get_u32(timeout);
 295                         _trigger_add(blobmsg_get_string(type), script, t, id);
 296                 }
 297         }
 298 }
 299
 300 void trigger_del(void *id)
 301 {
 302         struct trigger *t, *n;
 303
 304         list_for_each_entry_safe(t, n, &triggers, list) {
 305                 if (t->id != id)
 306                         continue;
 307
 308                 if (t->pending) {
 309                         t->remove = 1;
 310                         continue;
 311                 }
 312
 313                 trigger_free(t);
 314         }
 315 }
 316
 317 void trigger_init(void)
 318 {
 319         runqueue_init(&q);
 320         q.empty_cb = q_empty;
 321         q.max_running_tasks = 1;
 322 }
 323
 324 void trigger_event(char *type, struct blob_attr *data)
 325 {
 326         struct trigger *t;
 327
 328         list_for_each_entry(t, &triggers, list) {
 329                 if (t->pending || t->remove)
 330                         continue;
 331                 if (!strcmp(t->type, type)) {
 332                         if (t->timeout) {
 333                                 free(t->data);
 334                                 t->data = blob_memdup(data);
 335                                 uloop_timeout_set(&t->delay, t->timeout);
 336                         } else {
 337                                 json_script_run(&t->jctx, "foo", data);
 338                         }
 339                 }
 340         }
 341 }