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         LOG("handle event %s\n", j->cmd->name);
  88         j->cmd->handler(j, j->exec, j->env);
  89 }
  90
  91 static void q_job_complete(struct runqueue *q, struct runqueue_task *p)
  92 {
  93         struct job *j = container_of(p, struct job, proc.task);
  94
  95         if (j->trigger->remove) {
  96                 list_del(&j->trigger->list);
  97                 free(&j->trigger);
  98         } else {
  99                 j->trigger->pending = 0;
 100         }
 101         free(j);
 102 }
 103
 104 static void add_job(struct trigger *t, struct cmd *cmd, struct blob_attr *exec, struct blob_attr *data)
 105 {
 106         static const struct runqueue_task_type job_type = {
 107                 .run = q_job_run,
 108                 .cancel = runqueue_process_cancel_cb,
 109                 .kill = runqueue_process_kill_cb,
 110         };
 111         struct blob_attr *d, *e;
 112         struct job *j = calloc_a(sizeof(*j), &e, blob_pad_len(exec), &d, blob_pad_len(data));
 113
 114         j->env = d;
 115         j->exec = e;
 116         j->cmd = cmd;
 117         j->trigger = t;
 118         j->proc.task.type = &job_type;
 119         j->proc.task.complete = q_job_complete;
 120         t->pending = 1;
 121
 122         memcpy(j->exec, exec, blob_pad_len(exec));
 123         memcpy(j->env, data, blob_pad_len(data));
 124
 125         runqueue_task_add(&q, &j->proc.task, false);
 126 }
 127
 128 static void _setenv(const char *key, const char *val)
 129 {
 130         char _key[32];
 131
 132         snprintf(_key, sizeof(_key), "PARAM_%s", key);
 133         setenv(_key, val, 1);
 134 }
 135
 136 static void handle_run_script(struct job *j, struct blob_attr *exec, struct blob_attr *env)
 137 {
 138         char *argv[8];
 139         struct blob_attr *cur;
 140         int rem;
 141         int i = 0;
 142         pid_t pid;
 143
 144         pid = fork();
 145         if (pid < 0)
 146                 return;
 147
 148         if (pid) {
 149                 runqueue_process_add(&q, &j->proc, pid);
 150                 return;
 151         }
 152
 153         if (debug < 2) {
 154                 close(STDIN_FILENO);
 155                 close(STDOUT_FILENO);
 156                 close(STDERR_FILENO);
 157         }
 158
 159         _setenv("type", j->trigger->type);
 160         blobmsg_for_each_attr(cur, j->env, rem)
 161                 _setenv(blobmsg_name(cur), blobmsg_data(cur));
 162
 163         blobmsg_for_each_attr(cur, j->exec, rem) {
 164                 argv[i] = blobmsg_data(cur);
 165                 i++;
 166                 if (i == 7)
 167                         break;
 168         }
 169
 170         if (i > 0) {
 171                 argv[i] = NULL;
 172                 execvp(argv[0], &argv[0]);
 173         }
 174
 175         exit(1);
 176 }
 177
 178 static struct cmd handlers[] = {
 179         {
 180                 .name = "run_script",
 181                 .handler = handle_run_script,
 182         },
 183 };
 184
 185 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 186                                 struct blob_attr *exec, struct blob_attr *vars)
 187 {
 188         struct trigger *t = container_of(ctx, struct trigger, jctx);
 189         int i;
 190
 191         if (t->pending)
 192                 return;
 193
 194         for (i = 0; i < ARRAY_SIZE(handlers); i++) {
 195                 if (!strcmp(handlers[i].name, name)) {
 196                         add_job(t, &handlers[i], exec, vars);
 197                         break;
 198                 }
 199         }
 200 }
 201
 202 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 203                                 struct blob_attr *context)
 204 {
 205         char *s;
 206
 207         s = blobmsg_format_json(context, false);
 208         ERROR("ERROR: %s in block: %s\n", msg, s);
 209         free(s);
 210 }
 211
 212 static void q_empty(struct runqueue *q)
 213 {
 214 }
 215
 216 static void trigger_delay_cb(struct uloop_timeout *tout)
 217 {
 218         struct trigger *t = container_of(tout, struct trigger, delay);
 219
 220         json_script_run(&t->jctx, "foo", t->data);
 221         free(t->data);
 222 }
 223
 224 static struct trigger* _trigger_add(char *type, struct blob_attr *rule, int timeout, void *id)
 225 {
 226         char *_t;
 227         struct blob_attr *_r;
 228         struct trigger *t = calloc_a(sizeof(*t), &_t, strlen(type) + 1, &_r, blob_pad_len(rule));
 229
 230         t->type = _t;
 231         t->rule = _r;
 232         t->delay.cb = trigger_delay_cb;
 233         t->timeout = timeout;
 234         t->pending = 0;
 235         t->remove = 0;
 236         t->id = id;
 237         t->jctx.handle_var = rule_handle_var,
 238         t->jctx.handle_error = rule_handle_error,
 239         t->jctx.handle_command = rule_handle_command,
 240         t->jctx.handle_file = rule_load_script,
 241
 242         strcpy(t->type, type);
 243         memcpy(t->rule, rule, blob_pad_len(rule));
 244
 245         list_add(&t->list, &triggers);
 246         json_script_init(&t->jctx);
 247
 248         return t;
 249 }
 250
 251 void trigger_add(struct blob_attr *rule, void *id)
 252 {
 253         struct blob_attr *cur;
 254         int rem;
 255
 256         blobmsg_for_each_attr(cur, rule, rem) {
 257                 struct blob_attr *_cur, *type = NULL, *script = NULL, *timeout = NULL;
 258                 int _rem;
 259                 int i = 0;
 260
 261                 if (blobmsg_type(cur) != BLOBMSG_TYPE_ARRAY)
 262                         continue;
 263
 264                 blobmsg_for_each_attr(_cur, cur, _rem) {
 265                         switch (i++) {
 266                         case 0:
 267                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_STRING)
 268                                         type = _cur;
 269                                 break;
 270
 271                         case 1:
 272                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_ARRAY)
 273                                         script = _cur;
 274                                 break;
 275
 276                         case 2:
 277                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_INT32)
 278                                         timeout = _cur;
 279                                 break;
 280                         }
 281                 }
 282
 283                 if (type && script) {
 284                         int t = 0;
 285
 286                         if (timeout)
 287                                 t = blobmsg_get_u32(timeout);
 288                         _trigger_add(blobmsg_get_string(type), script, t, id);
 289                 }
 290         }
 291 }
 292
 293 void trigger_del(void *id)
 294 {
 295         struct trigger *t, *n;
 296
 297         list_for_each_entry_safe(t, n, &triggers, list) {
 298                 if (t->id != id)
 299                         continue;
 300
 301                 if (t->pending) {
 302                         t->remove = 1;
 303                         continue;
 304                 }
 305                 list_del(&t->list);
 306                 free(t);
 307         }
 308 }
 309
 310 void trigger_init(void)
 311 {
 312         runqueue_init(&q);
 313         q.empty_cb = q_empty;
 314         q.max_running_tasks = 1;
 315 }
 316
 317 void trigger_event(char *type, struct blob_attr *data)
 318 {
 319         struct trigger *t;
 320
 321         list_for_each_entry(t, &triggers, list) {
 322                 if (t->pending || t->remove)
 323                         continue;
 324                 if (!strcmp(t->type, type)) {
 325                         if (t->timeout) {
 326                                 t->data = malloc(blob_pad_len(data));
 327                                 memcpy(t->data, data, blob_pad_len(data));
 328                                 uloop_timeout_set(&t->delay, t->timeout);
 329                         } else {
 330                                 json_script_run(&t->jctx, "foo", data);
 331                         }
 332                 }
 333         }
 334 }