handler.c

   1 /*
   2  * netifd - network interface daemon
   3  * Copyright (C) 2012-2013 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2
   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 #define _GNU_SOURCE
  16 #include <glob.h>
  17 #include <fcntl.h>
  18 #include <stdio.h>
  19 #include <unistd.h>
  20
  21 #include "netifd.h"
  22 #include "system.h"
  23 #include "handler.h"
  24
  25 static int
  26 netifd_dir_push(int fd)
  27 {
  28         int prev_fd = open(".", O_RDONLY | O_DIRECTORY);
  29         system_fd_set_cloexec(prev_fd);
  30         if (fd >= 0)
  31                 fchdir(fd);
  32         return prev_fd;
  33 }
  34
  35 static void
  36 netifd_dir_pop(int prev_fd)
  37 {
  38         fchdir(prev_fd);
  39         close(prev_fd);
  40 }
  41
  42 int netifd_open_subdir(const char *name)
  43 {
  44         int prev_dir;
  45         int ret = -1;
  46
  47         prev_dir = netifd_dir_push(-1);
  48         if (chdir(main_path)) {
  49                 perror("chdir(main path)");
  50                 goto out;
  51         }
  52
  53         ret = open(name, O_RDONLY | O_DIRECTORY);
  54         if (ret >= 0)
  55                 system_fd_set_cloexec(ret);
  56
  57 out:
  58         netifd_dir_pop(prev_dir);
  59         return ret;
  60 }
  61
  62 static void
  63 netifd_init_script_handler(const char *name, script_dump_cb cb)
  64 {
  65         struct json_tokener *tok = NULL;
  66         json_object *obj;
  67         static char buf[512];
  68         char *start, *cmd;
  69         FILE *f;
  70         int len;
  71
  72 #define DUMP_SUFFIX     " '' dump"
  73
  74         cmd = alloca(strlen(name) + 1 + sizeof(DUMP_SUFFIX));
  75         sprintf(cmd, "%s" DUMP_SUFFIX, name);
  76
  77         f = popen(cmd, "r");
  78         if (!f)
  79                 return;
  80
  81         do {
  82                 start = fgets(buf, sizeof(buf), f);
  83                 if (!start)
  84                         continue;
  85
  86                 len = strlen(start);
  87
  88                 if (!tok)
  89                         tok = json_tokener_new();
  90
  91                 obj = json_tokener_parse_ex(tok, start, len);
  92                 if (!is_error(obj)) {
  93                         cb(name, obj);
  94                         json_object_put(obj);
  95                         json_tokener_free(tok);
  96                         tok = NULL;
  97                 } else if (start[len - 1] == '\n') {
  98                         json_tokener_free(tok);
  99                         tok = NULL;
 100                 }
 101         } while (!feof(f) && !ferror(f));
 102
 103         if (tok)
 104                 json_tokener_free(tok);
 105
 106         pclose(f);
 107 }
 108
 109 void netifd_init_script_handlers(int dir_fd, script_dump_cb cb)
 110 {
 111         glob_t g;
 112         int i, prev_fd;
 113
 114         prev_fd = netifd_dir_push(dir_fd);
 115         glob("./*.sh", 0, NULL, &g);
 116         for (i = 0; i < g.gl_pathc; i++)
 117                 netifd_init_script_handler(g.gl_pathv[i], cb);
 118         netifd_dir_pop(prev_fd);
 119 }