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[6];
  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         if (proto->iface->main_dev.dev) {
  77                 argv[4] = proto->iface->main_dev.dev->ifname;
  78                 argv[5] = NULL;
  79         }
  80
  81         switch(cmd) {
  82         case PROTO_CMD_SETUP:
  83                 argv[2] = "setup";
  84                 /* fall through */
  85         case PROTO_CMD_TEARDOWN:
  86                 ret = run_script(argv);
  87                 break;
  88         }
  89
  90         free(config);
  91
  92         return ret;
  93 }
  94
  95 static void
  96 proto_shell_free(struct interface_proto_state *proto)
  97 {
  98         struct proto_shell_state *state;
  99
 100         state = container_of(proto, struct proto_shell_state, proto);
 101         free(state->config);
 102         free(state);
 103 }
 104
 105 struct interface_proto_state *
 106 proto_shell_attach(const struct proto_handler *h, struct interface *iface,
 107                    struct blob_attr *attr)
 108 {
 109         struct proto_shell_state *state;
 110
 111         state = calloc(1, sizeof(*state));
 112         state->config = malloc(blob_pad_len(attr));
 113         if (!state->config)
 114                 goto error;
 115
 116         memcpy(state->config, attr, blob_pad_len(attr));
 117         state->proto.free = proto_shell_free;
 118         state->proto.cb = proto_shell_handler;
 119         state->handler = container_of(h, struct proto_shell_handler, proto);
 120
 121         return &state->proto;
 122
 123 error:
 124         free(state);
 125         return NULL;
 126 }
 127
 128 static json_object *
 129 check_type(json_object *obj, json_type type)
 130 {
 131         if (!obj)
 132                 return NULL;
 133
 134         if (json_object_get_type(obj) != type)
 135                 return NULL;
 136
 137         return obj;
 138 }
 139
 140 static inline json_object *
 141 get_field(json_object *obj, const char *name, json_type type)
 142 {
 143         return check_type(json_object_object_get(obj, name), type);
 144 }
 145
 146 static char *
 147 proto_shell_parse_config(struct config_param_list *config, json_object *obj)
 148 {
 149         struct blobmsg_policy *attrs;
 150         char *str_buf, *str_cur;
 151         int str_len = 0;
 152         int i;
 153
 154         attrs = calloc(1, sizeof(*attrs));
 155         if (!attrs)
 156                 return NULL;
 157
 158         config->n_params = json_object_array_length(obj);
 159         config->params = attrs;
 160         for (i = 0; i < config->n_params; i++) {
 161                 json_object *cur, *name, *type;
 162
 163                 cur = check_type(json_object_array_get_idx(obj, i), json_type_array);
 164                 if (!cur)
 165                         goto error;
 166
 167                 name = check_type(json_object_array_get_idx(cur, 0), json_type_string);
 168                 if (!name)
 169                         goto error;
 170
 171                 type = check_type(json_object_array_get_idx(cur, 1), json_type_int);
 172                 if (!type)
 173                         goto error;
 174
 175                 attrs[i].name = json_object_get_string(name);
 176                 attrs[i].type = json_object_get_int(type);
 177                 if (attrs[i].type > BLOBMSG_TYPE_LAST)
 178                         goto error;
 179
 180                 str_len += strlen(attrs[i].name + 1);
 181         }
 182
 183         str_buf = malloc(str_len);
 184         if (!str_buf)
 185                 goto error;
 186
 187         str_cur = str_buf;
 188         for (i = 0; i < config->n_params; i++) {
 189                 const char *name = attrs[i].name;
 190
 191                 attrs[i].name = str_cur;
 192                 str_cur += sprintf(str_cur, "%s", name) + 1;
 193         }
 194
 195         return str_buf;
 196
 197 error:
 198         free(attrs);
 199         config->n_params = 0;
 200         return NULL;
 201 }
 202
 203 static void
 204 proto_shell_add_handler(const char *script, json_object *obj)
 205 {
 206         struct proto_shell_handler *handler;
 207         struct proto_handler *proto;
 208         json_object *config, *tmp;
 209         const char *name;
 210         char *str;
 211
 212         if (!check_type(obj, json_type_object))
 213                 return;
 214
 215         tmp = get_field(obj, "name", json_type_string);
 216         if (!tmp)
 217                 return;
 218
 219         name = json_object_get_string(tmp);
 220
 221         handler = calloc(1, sizeof(*handler) +
 222                          strlen(script) + 1 +
 223                          strlen(name) + 1);
 224         if (!handler)
 225                 return;
 226
 227         strcpy(handler->script_name, script);
 228
 229         str = handler->script_name + strlen(handler->script_name) + 1;
 230         strcpy(str, name);
 231
 232         proto = &handler->proto;
 233         proto->name = str;
 234         proto->config_params = &handler->config;
 235         proto->attach = proto_shell_attach;
 236
 237         tmp = get_field(obj, "no-device", json_type_boolean);
 238         if (tmp && json_object_get_boolean(tmp))
 239                 handler->proto.flags |= PROTO_FLAG_NODEV;
 240
 241         config = get_field(obj, "config", json_type_array);
 242         if (config)
 243                 handler->config_buf = proto_shell_parse_config(&handler->config, config);
 244
 245         DPRINTF("Add handler for script %s: %s\n", script, proto->name);
 246         add_proto_handler(proto);
 247 }
 248
 249 static void proto_shell_add_script(const char *name)
 250 {
 251         struct json_tokener *tok = NULL;
 252         json_object *obj;
 253         static char buf[512];
 254         char *start, *end, *cmd;
 255         FILE *f;
 256         int buflen, len;
 257
 258 #define DUMP_SUFFIX     " '' dump"
 259
 260         cmd = alloca(strlen(name) + 1 + sizeof(DUMP_SUFFIX));
 261         sprintf(cmd, "%s" DUMP_SUFFIX, name);
 262
 263         f = popen(cmd, "r");
 264         if (!f)
 265                 return;
 266
 267         do {
 268                 buflen = fread(buf, 1, sizeof(buf) - 1, f);
 269                 if (buflen <= 0)
 270                         continue;
 271
 272                 start = buf;
 273                 len = buflen;
 274                 do {
 275                         end = memchr(start, '\n', len);
 276                         if (end)
 277                                 len = end - start;
 278
 279                         if (!tok)
 280                                 tok = json_tokener_new();
 281
 282                         obj = json_tokener_parse_ex(tok, start, len);
 283                         if (!is_error(obj)) {
 284                                 proto_shell_add_handler(name, obj);
 285                                 json_object_put(obj);
 286                                 json_tokener_free(tok);
 287                                 tok = NULL;
 288                         }
 289
 290                         if (end) {
 291                                 start = end + 1;
 292                                 len = buflen - (start - buf);
 293                         }
 294                 } while (len > 0);
 295         } while (!feof(f) && !ferror(f));
 296
 297         if (tok)
 298                 json_tokener_free(tok);
 299
 300         pclose(f);
 301 }
 302
 303 void __init proto_shell_init(void)
 304 {
 305         glob_t g;
 306         int main_fd;
 307         int i;
 308
 309         main_fd = open(".", O_RDONLY | O_DIRECTORY);
 310         if (main_fd < 0)
 311                 return;
 312
 313         if (chdir(main_path)) {
 314                 perror("chdir(main path)");
 315                 goto close_cur;
 316         }
 317
 318         if (chdir("./proto"))
 319                 goto close_cur;
 320
 321         proto_fd = open(".", O_RDONLY | O_DIRECTORY);
 322         if (proto_fd < 0)
 323                 goto close_cur;
 324
 325         glob("./*.sh", 0, NULL, &g);
 326         for (i = 0; i < g.gl_pathc; i++)
 327                 proto_shell_add_script(g.gl_pathv[i]);
 328
 329 close_cur:
 330         fchdir(main_fd);
 331         close(main_fd);
 332 }