proto-shell.c

   1 #include <string.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <glob.h>
   5 #include <unistd.h>
   6 #include <fcntl.h>
   7
   8 #include <libubox/blobmsg_json.h>
   9
  10 #include "netifd.h"
  11 #include "interface.h"
  12 #include "interface-ip.h"
  13 #include "proto.h"
  14
  15 static LIST_HEAD(handlers);
  16 static int proto_fd;
  17
  18 struct proto_shell_handler {
  19         struct list_head list;
  20         struct proto_handler proto;
  21         struct config_param_list config;
  22         char *config_buf;
  23         char script_name[];
  24 };
  25
  26 struct proto_shell_state {
  27         struct interface_proto_state proto;
  28         struct proto_shell_handler *handler;
  29         struct blob_attr *config;
  30 };
  31
  32 static int run_script(const char **argv)
  33 {
  34         int pid, ret;
  35
  36         if ((pid = fork()) < 0)
  37                 return -1;
  38
  39         if (!pid) {
  40                 fchdir(proto_fd);
  41                 execvp(argv[0], (char **) argv);
  42                 exit(127);
  43         }
  44
  45         if (waitpid(pid, &ret, 0) == -1)
  46                 ret = -1;
  47
  48         if (ret > 0)
  49                 return -ret;
  50
  51         return 0;
  52 }
  53
  54 static int
  55 proto_shell_handler(struct interface_proto_state *proto,
  56                     enum interface_proto_cmd cmd, bool force)
  57 {
  58         struct proto_shell_state *state;
  59         struct proto_shell_handler *handler;
  60         const char *argv[5];
  61         char *config;
  62         int ret;
  63
  64         state = container_of(proto, struct proto_shell_state, proto);
  65         handler = state->handler;
  66
  67         config = blobmsg_format_json(state->config, true);
  68         if (!config)
  69                 return -1;
  70
  71         argv[0] = handler->script_name;
  72         argv[1] = handler->proto.name;
  73         argv[2] = "teardown";
  74         argv[3] = config;
  75         argv[4] = NULL;
  76
  77         switch(cmd) {
  78         case PROTO_CMD_SETUP:
  79                 argv[2] = "setup";
  80                 /* fall through */
  81         case PROTO_CMD_TEARDOWN:
  82                 ret = run_script(argv);
  83                 break;
  84         }
  85
  86         free(config);
  87
  88         return ret;
  89 }
  90
  91 static void
  92 proto_shell_free(struct interface_proto_state *proto)
  93 {
  94         struct proto_shell_state *state;
  95
  96         state = container_of(proto, struct proto_shell_state, proto);
  97         free(state->config);
  98         free(state);
  99 }
 100
 101 struct interface_proto_state *
 102 proto_shell_attach(const struct proto_handler *h, struct interface *iface,
 103                    struct blob_attr *attr)
 104 {
 105         struct proto_shell_state *state;
 106
 107         state = calloc(1, sizeof(*state));
 108         state->config = malloc(blob_pad_len(attr));
 109         if (!state->config)
 110                 goto error;
 111
 112         memcpy(state->config, attr, blob_pad_len(attr));
 113         state->proto.free = proto_shell_free;
 114         state->proto.cb = proto_shell_handler;
 115         state->handler = container_of(h, struct proto_shell_handler, proto);
 116
 117         return &state->proto;
 118
 119 error:
 120         free(state);
 121         return NULL;
 122 }
 123
 124 static json_object *
 125 check_type(json_object *obj, json_type type)
 126 {
 127         if (!obj)
 128                 return NULL;
 129
 130         if (json_object_get_type(obj) != type)
 131                 return NULL;
 132
 133         return obj;
 134 }
 135
 136 static inline json_object *
 137 get_field(json_object *obj, const char *name, json_type type)
 138 {
 139         return check_type(json_object_object_get(obj, name), type);
 140 }
 141
 142 static char *
 143 proto_shell_parse_config(struct config_param_list *config, json_object *obj)
 144 {
 145         struct blobmsg_policy *attrs;
 146         char *str_buf, *str_cur;
 147         int str_len = 0;
 148         int i;
 149
 150         attrs = calloc(1, sizeof(*attrs));
 151         if (!attrs)
 152                 return NULL;
 153
 154         config->n_params = json_object_array_length(obj);
 155         config->params = attrs;
 156         for (i = 0; i < config->n_params; i++) {
 157                 json_object *cur, *name, *type;
 158
 159                 cur = check_type(json_object_array_get_idx(obj, i), json_type_array);
 160                 if (!cur)
 161                         goto error;
 162
 163                 name = check_type(json_object_array_get_idx(cur, 0), json_type_string);
 164                 if (!name)
 165                         goto error;
 166
 167                 type = check_type(json_object_array_get_idx(cur, 1), json_type_int);
 168                 if (!type)
 169                         goto error;
 170
 171                 attrs[i].name = json_object_get_string(name);
 172                 attrs[i].type = json_object_get_int(type);
 173                 if (attrs[i].type > BLOBMSG_TYPE_LAST)
 174                         goto error;
 175
 176                 str_len += strlen(attrs[i].name + 1);
 177         }
 178
 179         str_buf = malloc(str_len);
 180         if (!str_buf)
 181                 goto error;
 182
 183         str_cur = str_buf;
 184         for (i = 0; i < config->n_params; i++) {
 185                 const char *name = attrs[i].name;
 186
 187                 attrs[i].name = str_cur;
 188                 str_cur += sprintf(str_cur, "%s", name) + 1;
 189         }
 190
 191         return str_buf;
 192
 193 error:
 194         free(attrs);
 195         config->n_params = 0;
 196         return NULL;
 197 }
 198
 199 static void
 200 proto_shell_add_handler(const char *script, json_object *obj)
 201 {
 202         struct proto_shell_handler *handler;
 203         struct proto_handler *proto;
 204         json_object *config, *tmp;
 205         const char *name;
 206         char *str;
 207
 208         if (!check_type(obj, json_type_object))
 209                 return;
 210
 211         tmp = get_field(obj, "name", json_type_string);
 212         if (!tmp)
 213                 return;
 214
 215         name = json_object_get_string(tmp);
 216
 217         handler = calloc(1, sizeof(*handler) +
 218                          strlen(script) + 1 +
 219                          strlen(name) + 1);
 220         if (!handler)
 221                 return;
 222
 223         strcpy(handler->script_name, script);
 224
 225         str = handler->script_name + strlen(handler->script_name) + 1;
 226         strcpy(str, name);
 227
 228         proto = &handler->proto;
 229         proto->name = str;
 230         proto->config_params = &handler->config;
 231         proto->attach = proto_shell_attach;
 232
 233         tmp = get_field(obj, "no-device", json_type_boolean);
 234         if (tmp && json_object_get_boolean(tmp))
 235                 handler->proto.flags |= PROTO_FLAG_NODEV;
 236
 237         config = get_field(obj, "config", json_type_array);
 238         if (config)
 239                 handler->config_buf = proto_shell_parse_config(&handler->config, config);
 240
 241         DPRINTF("Add handler for script %s: %s\n", script, proto->name);
 242         add_proto_handler(proto);
 243 }
 244
 245 static void proto_shell_add_script(const char *name)
 246 {
 247         struct json_tokener *tok = NULL;
 248         json_object *obj;
 249         static char buf[512];
 250         char *start, *end, *cmd;
 251         FILE *f;
 252         int buflen, len;
 253
 254 #define DUMP_SUFFIX     " '' dump"
 255
 256         cmd = alloca(strlen(name) + 1 + sizeof(DUMP_SUFFIX));
 257         sprintf(cmd, "%s" DUMP_SUFFIX, name);
 258
 259         f = popen(cmd, "r");
 260         if (!f)
 261                 return;
 262
 263         do {
 264                 buflen = fread(buf, 1, sizeof(buf) - 1, f);
 265                 if (buflen <= 0)
 266                         continue;
 267
 268                 start = buf;
 269                 len = buflen;
 270                 do {
 271                         end = memchr(start, '\n', len);
 272                         if (end)
 273                                 len = end - start;
 274
 275                         if (!tok)
 276                                 tok = json_tokener_new();
 277
 278                         obj = json_tokener_parse_ex(tok, start, len);
 279                         if (!is_error(obj)) {
 280                                 proto_shell_add_handler(name, obj);
 281                                 json_object_put(obj);
 282                                 json_tokener_free(tok);
 283                                 tok = NULL;
 284                         }
 285
 286                         if (end) {
 287                                 start = end + 1;
 288                                 len = buflen - (start - buf);
 289                         }
 290                 } while (len > 0);
 291         } while (!feof(f) && !ferror(f));
 292
 293         if (tok)
 294                 json_tokener_free(tok);
 295
 296         pclose(f);
 297 }
 298
 299 void __init proto_shell_init(void)
 300 {
 301         glob_t g;
 302         int main_fd;
 303         int i;
 304
 305         main_fd = open(".", O_RDONLY | O_DIRECTORY);
 306         if (main_fd < 0)
 307                 return;
 308
 309         if (chdir(main_path)) {
 310                 perror("chdir(main path)");
 311                 goto close_cur;
 312         }
 313
 314         if (chdir("./proto"))
 315                 goto close_cur;
 316
 317         proto_fd = open(".", O_RDONLY | O_DIRECTORY);
 318         if (proto_fd < 0)
 319                 goto close_cur;
 320
 321         glob("./*.sh", 0, NULL, &g);
 322         for (i = 0; i < g.gl_pathc; i++)
 323                 proto_shell_add_script(g.gl_pathv[i]);
 324
 325 close_cur:
 326         fchdir(main_fd);
 327         close(main_fd);
 328 }