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 <libubox/blobmsg_json.h>
  20 #include <libubox/json_script.h>
  21 #include <libubox/runqueue.h>
  22 #include <libubox/ustream.h>
  23 #include <libubox/uloop.h>
  24 #include <libubox/avl.h>
  25 #include <libubox/avl-cmp.h>
  26
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <stdlib.h>
  30 #include <libgen.h>
  31
  32 #include "../procd.h"
  33
  34 struct trigger {
  35         struct list_head list;
  36
  37         void *id;
  38         char *type;
  39         int timeout;
  40
  41         struct blob_attr *rule;
  42         struct blob_attr *data;
  43
  44         struct json_script_ctx jctx;
  45 };
  46
  47 struct trigger_command {
  48         struct avl_node avl;
  49         struct uloop_timeout delay;
  50         bool requeue;
  51
  52         struct runqueue_process proc;
  53         struct json_script_ctx jctx;
  54
  55         struct blob_attr data[];
  56 };
  57
  58 static LIST_HEAD(triggers);
  59 static RUNQUEUE(q, 1);
  60 static AVL_TREE(trigger_pending, avl_blobcmp, false, NULL);
  61
  62 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
  63 {
  64         return NULL;
  65 }
  66
  67 static struct json_script_file *
  68 rule_load_script(struct json_script_ctx *ctx, const char *name)
  69 {
  70         struct trigger *t = container_of(ctx, struct trigger, jctx);
  71
  72         if (strcmp(name, t->type) != 0)
  73                 return NULL;
  74
  75         return json_script_file_from_blobmsg(t->type, t->rule, blob_pad_len(t->rule));
  76 }
  77
  78 static void trigger_free(struct trigger *t)
  79 {
  80         json_script_free(&t->jctx);
  81         free(t->data);
  82         list_del(&t->list);
  83         free(t);
  84 }
  85
  86 static void trigger_command_complete(struct runqueue *q, struct runqueue_task *p)
  87 {
  88         struct trigger_command *cmd = container_of(p, struct trigger_command, proc.task);
  89
  90         if (cmd->requeue) {
  91                 cmd->requeue = false;
  92                 runqueue_task_add(q, p, false);
  93                 return;
  94         }
  95
  96         avl_delete(&trigger_pending, &cmd->avl);
  97         free(cmd);
  98 }
  99
 100 static void trigger_command_run(struct runqueue *q, struct runqueue_task *t)
 101 {
 102         struct trigger_command *cmd = container_of(t, struct trigger_command, proc.task);
 103         struct blob_attr *cur;
 104         char **argv;
 105         pid_t pid;
 106         int n = 0;
 107         int rem;
 108
 109         pid = fork();
 110         if (pid < 0) {
 111                 trigger_command_complete(q, t);
 112                 return;
 113         }
 114
 115         if (pid) {
 116                 runqueue_process_add(q, &cmd->proc, pid);
 117                 return;
 118         }
 119
 120         if (debug < 3) {
 121                 close(STDIN_FILENO);
 122                 close(STDOUT_FILENO);
 123                 close(STDERR_FILENO);
 124         }
 125
 126         blobmsg_for_each_attr(cur, cmd->data, rem)
 127                 n++;
 128
 129         argv = alloca((n + 1) * sizeof(*argv));
 130         n = 0;
 131         blobmsg_for_each_attr(cur, cmd->data, rem)
 132                 argv[n++] = blobmsg_get_string(cur);
 133         argv[n] = NULL;
 134
 135         if (n > 0)
 136                 execvp(argv[0], &argv[0]);
 137
 138         exit(1);
 139 }
 140
 141 static void trigger_command_start(struct uloop_timeout *timeout)
 142 {
 143         static const struct runqueue_task_type trigger_command_type = {
 144                 .run = trigger_command_run,
 145                 .cancel = runqueue_process_cancel_cb,
 146                 .kill = runqueue_process_kill_cb,
 147         };
 148         struct trigger_command *cmd = container_of(timeout, struct trigger_command, delay);
 149
 150         cmd->proc.task.type = &trigger_command_type;
 151         cmd->proc.task.complete = trigger_command_complete;
 152         runqueue_task_add(&q, &cmd->proc.task, false);
 153 }
 154
 155 static void trigger_command_add(struct trigger *t, struct blob_attr *data)
 156 {
 157         struct trigger_command *cmd;
 158         int remaining;
 159
 160         cmd = avl_find_element(&trigger_pending, data, cmd, avl);
 161         if (cmd) {
 162                 /* Command currently running? */
 163                 if (!cmd->delay.pending) {
 164                         cmd->requeue = true;
 165                         return;
 166                 }
 167
 168                 /* Extend timer if trigger timeout is bigger than remaining time */
 169                 remaining = uloop_timeout_remaining(&cmd->delay);
 170                 if (remaining < t->timeout)
 171                         uloop_timeout_set(&cmd->delay, t->timeout);
 172
 173                 return;
 174         }
 175
 176         cmd = calloc(1, sizeof(*cmd) + blob_pad_len(data));
 177         if (!cmd)
 178                 return;
 179
 180         cmd->avl.key = cmd->data;
 181         cmd->delay.cb = trigger_command_start;
 182         memcpy(cmd->data, data, blob_pad_len(data));
 183         avl_insert(&trigger_pending, &cmd->avl);
 184         uloop_timeout_set(&cmd->delay, t->timeout > 0 ? t->timeout : 1);
 185 }
 186
 187 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 188                                 struct blob_attr *exec, struct blob_attr *vars)
 189 {
 190         struct trigger *t = container_of(ctx, struct trigger, jctx);
 191
 192         if (!strcmp(name, "run_script")) {
 193                 trigger_command_add(t, exec);
 194                 return;
 195         }
 196 }
 197
 198 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 199                                 struct blob_attr *context)
 200 {
 201         char *s;
 202
 203         s = blobmsg_format_json(context, false);
 204         ERROR("ERROR: %s in block: %s\n", msg, s);
 205         free(s);
 206 }
 207
 208 static struct trigger* _trigger_add(char *type, struct blob_attr *rule, int timeout, void *id)
 209 {
 210         char *_t;
 211         struct blob_attr *_r;
 212         struct trigger *t = calloc_a(sizeof(*t), &_t, strlen(type) + 1, &_r, blob_pad_len(rule));
 213
 214         t->type = _t;
 215         t->rule = _r;
 216         t->timeout = timeout;
 217         t->id = id;
 218         t->jctx.handle_var = rule_handle_var,
 219         t->jctx.handle_error = rule_handle_error,
 220         t->jctx.handle_command = rule_handle_command,
 221         t->jctx.handle_file = rule_load_script,
 222
 223         strcpy(t->type, type);
 224         memcpy(t->rule, rule, blob_pad_len(rule));
 225
 226         list_add(&t->list, &triggers);
 227         json_script_init(&t->jctx);
 228
 229         return t;
 230 }
 231
 232 void trigger_add(struct blob_attr *rule, void *id)
 233 {
 234         struct blob_attr *cur;
 235         int rem;
 236
 237         blobmsg_for_each_attr(cur, rule, rem) {
 238                 struct blob_attr *_cur, *type = NULL, *script = NULL, *timeout = NULL;
 239                 int _rem;
 240                 int i = 0;
 241
 242                 if (blobmsg_type(cur) != BLOBMSG_TYPE_ARRAY)
 243                         continue;
 244
 245                 blobmsg_for_each_attr(_cur, cur, _rem) {
 246                         switch (i++) {
 247                         case 0:
 248                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_STRING)
 249                                         type = _cur;
 250                                 break;
 251
 252                         case 1:
 253                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_ARRAY)
 254                                         script = _cur;
 255                                 break;
 256
 257                         case 2:
 258                                 if (blobmsg_type(_cur) == BLOBMSG_TYPE_INT32)
 259                                         timeout = _cur;
 260                                 break;
 261                         }
 262                 }
 263
 264                 if (type && script) {
 265                         int t = 0;
 266
 267                         if (timeout)
 268                                 t = blobmsg_get_u32(timeout);
 269                         _trigger_add(blobmsg_get_string(type), script, t, id);
 270                 }
 271         }
 272 }
 273
 274 void trigger_del(void *id)
 275 {
 276         struct trigger *t, *n;
 277
 278         list_for_each_entry_safe(t, n, &triggers, list) {
 279                 if (t->id != id)
 280                         continue;
 281
 282                 trigger_free(t);
 283         }
 284 }
 285
 286 static bool trigger_match(const char *event, const char *match)
 287 {
 288         char *wildcard = strstr(match, ".*");
 289         if (wildcard)
 290                 return !strncmp(event, match, wildcard - match);
 291         return !strcmp(event, match);
 292 }
 293
 294 void trigger_event(const char *type, struct blob_attr *data)
 295 {
 296         struct trigger *t;
 297
 298         list_for_each_entry(t, &triggers, list) {
 299                 if (!trigger_match(type, t->type))
 300                         continue;
 301                 json_script_run(&t->jctx, t->type, data);
 302         }
 303 }