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         uloop_timeout_cancel(&t->delay);
  94         free(t->data);
  95         list_del(&t->list);
  96         free(t);
  97 }
  98
  99 static void q_job_complete(struct runqueue *q, struct runqueue_task *p)
 100 {
 101         struct job *j = container_of(p, struct job, proc.task);
 102
 103         if (j->trigger->remove) {
 104                 trigger_free(j->trigger);
 105         } else {
 106                 j->trigger->pending = 0;
 107         }
 108         free(j);
 109 }
 110
 111 static void add_job(struct trigger *t, struct cmd *cmd, struct blob_attr *exec, struct blob_attr *data)
 112 {
 113         static const struct runqueue_task_type job_type = {
 114                 .run = q_job_run,
 115                 .cancel = runqueue_process_cancel_cb,
 116                 .kill = runqueue_process_kill_cb,
 117         };
 118         struct blob_attr *d, *e;
 119         struct job *j = calloc_a(sizeof(*j), &e, blob_pad_len(exec), &d, blob_pad_len(data));
 120
 121         j->env = d;
 122         j->exec = e;
 123         j->cmd = cmd;
 124         j->trigger = t;
 125         j->proc.task.type = &job_type;
 126         j->proc.task.complete = q_job_complete;
 127         t->pending = 1;
 128
 129         memcpy(j->exec, exec, blob_pad_len(exec));
 130         memcpy(j->env, data, blob_pad_len(data));
 131
 132         runqueue_task_add(&q, &j->proc.task, false);
 133 }
 134
 135 static void _setenv(const char *key, const char *val)
 136 {
 137         char _key[32];
 138
 139         snprintf(_key, sizeof(_key), "PARAM_%s", key);
 140         setenv(_key, val, 1);
 141 }
 142
 143 static void handle_run_script(struct job *j, struct blob_attr *exec, struct blob_attr *env)
 144 {
 145         char *argv[8];
 146         struct blob_attr *cur;
 147         int rem;
 148         int i = 0;
 149         pid_t pid;
 150
 151         pid = fork();
 152         if (pid < 0)
 153                 return;
 154
 155         if (pid) {
 156                 runqueue_process_add(&q, &j->proc, pid);
 157                 return;
 158         }
 159
 160         if (debug < 3) {
 161                 close(STDIN_FILENO);
 162                 close(STDOUT_FILENO);
 163                 close(STDERR_FILENO);
 164         }
 165
 166         _setenv("type", j->trigger->type);
 167         blobmsg_for_each_attr(cur, j->env, rem)
 168                 _setenv(blobmsg_name(cur), blobmsg_data(cur));
 169
 170         blobmsg_for_each_attr(cur, j->exec, rem) {
 171                 argv[i] = blobmsg_data(cur);
 172                 i++;
 173                 if (i == 7)
 174                         break;
 175         }
 176
 177         if (i > 0) {
 178                 argv[i] = NULL;
 179                 execvp(argv[0], &argv[0]);
 180         }
 181
 182         exit(1);
 183 }
 184
 185 static struct cmd handlers[] = {
 186         {
 187                 .name = "run_script",
 188                 .handler = handle_run_script,
 189         },
 190 };
 191
 192 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 193                                 struct blob_attr *exec, struct blob_attr *vars)
 194 {
 195         struct trigger *t = container_of(ctx, struct trigger, jctx);
 196         int i;
 197
 198         if (t->pending)
 199                 return;
 200
 201         for (i = 0; i < ARRAY_SIZE(handlers); i++) {
 202                 if (!strcmp(handlers[i].name, name)) {
 203                         add_job(t, &handlers[i], exec, vars);
 204                         break;
 205                 }
 206         }
 207 }
 208
 209 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 210                                 struct blob_attr *context)
 211 {
 212         char *s;
 213
 214         s = blobmsg_format_json(context, false);
 215         ERROR("ERROR: %s in block: %s\n", msg, s);
 216         free(s);
 217 }
 218
 219 static void q_empty(struct runqueue *q)
 220 {
 221 }
 222
 223 static void trigger_delay_cb(struct uloop_timeout *tout)
 224 {
 225         struct trigger *t = container_of(tout, struct trigger, delay);
 226
 227         json_script_run(&t->jctx, "foo", t->data);
 228         free(t->data);
 229         t->data = NULL;
 230 }
 231
 232 static struct trigger* _trigger_add(char *type, struct blob_attr *rule, int timeout, void *id)
 233 {
 234         char *_t;
 235         struct blob_attr *_r;
 236         struct trigger *t = calloc_a(sizeof(*t), &_t, strlen(type) + 1, &_r, blob_pad_len(rule));
 237
 238         t->type = _t;
 239         t->rule = _r;
 240         t->delay.cb = trigger_delay_cb;
 241         t->timeout = timeout;
 242         t->pending = 0;
 243         t->remove = 0;
 244         t->id = id;
 245         t->jctx.handle_var = rule_handle_var,
 246         t->jctx.handle_error = rule_handle_error,
 247         t->jctx.handle_command = rule_handle_command,
 248         t->jctx.handle_file = rule_load_script,
 249
 250         strcpy(t->type, type);
 251         memcpy(t->rule, rule, blob_pad_len(rule));
 252
 253         list_add(&t->list, &triggers);
 254         json_script_init(&t->jctx);
 255
 256         return t;
 257 }
 258
 259 void trigger_add(struct blob_attr *rule, void *id)
 260 {
 261         struct blob_attr *cur;
 262         int rem;
 263
 264         blobmsg_for_each_attr(cur, rule, rem) {
 265                 struct blob_attr *_cur, *type = NULL, *script = NULL, *timeout = NULL;
 266                 int _rem;
 267                 int i = 0;
 268
 269                 if (blobmsg_type(cur) != BLOBMSG_TYPE_ARRAY)
 270                         continue;
 271
 272                 blobmsg_for_each_attr(_cur, cur, _rem) {
 273                         switch (i++) {
 274                         case 0:
 275                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_STRING)
 276                                         type = _cur;
 277                                 break;
 278
 279                         case 1:
 280                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_ARRAY)
 281                                         script = _cur;
 282                                 break;
 283
 284                         case 2:
 285                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_INT32)
 286                                         timeout = _cur;
 287                                 break;
 288                         }
 289                 }
 290
 291                 if (type && script) {
 292                         int t = 0;
 293
 294                         if (timeout)
 295                                 t = blobmsg_get_u32(timeout);
 296                         _trigger_add(blobmsg_get_string(type), script, t, id);
 297                 }
 298         }
 299 }
 300
 301 void trigger_del(void *id)
 302 {
 303         struct trigger *t, *n;
 304
 305         list_for_each_entry_safe(t, n, &triggers, list) {
 306                 if (t->id != id)
 307                         continue;
 308
 309                 if (t->pending) {
 310                         t->remove = 1;
 311                         continue;
 312                 }
 313
 314                 trigger_free(t);
 315         }
 316 }
 317
 318 void trigger_init(void)
 319 {
 320         runqueue_init(&q);
 321         q.empty_cb = q_empty;
 322         q.max_running_tasks = 1;
 323 }
 324
 325 void trigger_event(char *type, struct blob_attr *data)
 326 {
 327         struct trigger *t;
 328
 329         list_for_each_entry(t, &triggers, list) {
 330                 if (t->pending || t->remove)
 331                         continue;
 332                 if (!strcmp(t->type, type)) {
 333                         if (t->timeout) {
 334                                 free(t->data);
 335                                 t->data = blob_memdup(data);
 336                                 uloop_timeout_set(&t->delay, t->timeout);
 337                         } else {
 338                                 json_script_run(&t->jctx, "foo", data);
 339                         }
 340                 }
 341         }
 342 }