src/common/wpa_ctrl.c

   1 /*
   2  * wpa_supplicant/hostapd control interface library
   3  * Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
   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 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #ifdef CONFIG_CTRL_IFACE
  18
  19 #ifdef CONFIG_CTRL_IFACE_UNIX
  20 #include <sys/un.h>
  21 #endif /* CONFIG_CTRL_IFACE_UNIX */
  22
  23 #ifdef ANDROID
  24 #include <cutils/sockets.h>
  25 #include "private/android_filesystem_config.h"
  26 #endif /* ANDROID */
  27
  28 #include "wpa_ctrl.h"
  29 #include "common.h"
  30
  31
  32 #if defined(CONFIG_CTRL_IFACE_UNIX) || defined(CONFIG_CTRL_IFACE_UDP)
  33 #define CTRL_IFACE_SOCKET
  34 #endif /* CONFIG_CTRL_IFACE_UNIX || CONFIG_CTRL_IFACE_UDP */
  35
  36
  37 /**
  38  * struct wpa_ctrl - Internal structure for control interface library
  39  *
  40  * This structure is used by the wpa_supplicant/hostapd control interface
  41  * library to store internal data. Programs using the library should not touch
  42  * this data directly. They can only use the pointer to the data structure as
  43  * an identifier for the control interface connection and use this as one of
  44  * the arguments for most of the control interface library functions.
  45  */
  46 struct wpa_ctrl {
  47 #ifdef CONFIG_CTRL_IFACE_UDP
  48         int s;
  49         struct sockaddr_in local;
  50         struct sockaddr_in dest;
  51         char *cookie;
  52 #endif /* CONFIG_CTRL_IFACE_UDP */
  53 #ifdef CONFIG_CTRL_IFACE_UNIX
  54         int s;
  55         struct sockaddr_un local;
  56         struct sockaddr_un dest;
  57 #endif /* CONFIG_CTRL_IFACE_UNIX */
  58 #ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
  59         HANDLE pipe;
  60 #endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
  61 };
  62
  63
  64 #ifdef CONFIG_CTRL_IFACE_UNIX
  65
  66 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
  67 {
  68         struct wpa_ctrl *ctrl;
  69         static int counter = 0;
  70         int ret;
  71         size_t res;
  72         int tries = 0;
  73
  74         ctrl = os_malloc(sizeof(*ctrl));
  75         if (ctrl == NULL)
  76                 return NULL;
  77         os_memset(ctrl, 0, sizeof(*ctrl));
  78
  79         ctrl->s = socket(PF_UNIX, SOCK_DGRAM, 0);
  80         if (ctrl->s < 0) {
  81                 os_free(ctrl);
  82                 return NULL;
  83         }
  84
  85         ctrl->local.sun_family = AF_UNIX;
  86         counter++;
  87 try_again:
  88         ret = os_snprintf(ctrl->local.sun_path, sizeof(ctrl->local.sun_path),
  89                           "/tmp/wpa_ctrl_%d-%d", (int) getpid(), counter);
  90         if (ret < 0 || (size_t) ret >= sizeof(ctrl->local.sun_path)) {
  91                 close(ctrl->s);
  92                 os_free(ctrl);
  93                 return NULL;
  94         }
  95         tries++;
  96         if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
  97                     sizeof(ctrl->local)) < 0) {
  98                 if (errno == EADDRINUSE && tries < 2) {
  99                         /*
 100                          * getpid() returns unique identifier for this instance
 101                          * of wpa_ctrl, so the existing socket file must have
 102                          * been left by unclean termination of an earlier run.
 103                          * Remove the file and try again.
 104                          */
 105                         unlink(ctrl->local.sun_path);
 106                         goto try_again;
 107                 }
 108                 close(ctrl->s);
 109                 os_free(ctrl);
 110                 return NULL;
 111         }
 112
 113 #ifdef ANDROID
 114         chmod(ctrl->local.sun_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 115         chown(ctrl->local.sun_path, AID_SYSTEM, AID_WIFI);
 116         /*
 117          * If the ctrl_path isn't an absolute pathname, assume that
 118          * it's the name of a socket in the Android reserved namespace.
 119          * Otherwise, it's a normal UNIX domain socket appearing in the
 120          * filesystem.
 121          */
 122         if (ctrl_path != NULL && *ctrl_path != '/') {
 123                 char buf[21];
 124                 os_snprintf(buf, sizeof(buf), "wpa_%s", ctrl_path);
 125                 if (socket_local_client_connect(
 126                             ctrl->s, buf,
 127                             ANDROID_SOCKET_NAMESPACE_RESERVED,
 128                             SOCK_DGRAM) < 0) {
 129                         close(ctrl->s);
 130                         unlink(ctrl->local.sun_path);
 131                         os_free(ctrl);
 132                         return NULL;
 133                 }
 134                 return ctrl;
 135         }
 136 #endif /* ANDROID */
 137
 138         ctrl->dest.sun_family = AF_UNIX;
 139         res = os_strlcpy(ctrl->dest.sun_path, ctrl_path,
 140                          sizeof(ctrl->dest.sun_path));
 141         if (res >= sizeof(ctrl->dest.sun_path)) {
 142                 close(ctrl->s);
 143                 os_free(ctrl);
 144                 return NULL;
 145         }
 146         if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
 147                     sizeof(ctrl->dest)) < 0) {
 148                 close(ctrl->s);
 149                 unlink(ctrl->local.sun_path);
 150                 os_free(ctrl);
 151                 return NULL;
 152         }
 153
 154         return ctrl;
 155 }
 156
 157
 158 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 159 {
 160         if (ctrl == NULL)
 161                 return;
 162         unlink(ctrl->local.sun_path);
 163         if (ctrl->s >= 0)
 164                 close(ctrl->s);
 165         os_free(ctrl);
 166 }
 167
 168 #endif /* CONFIG_CTRL_IFACE_UNIX */
 169
 170
 171 #ifdef CONFIG_CTRL_IFACE_UDP
 172
 173 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
 174 {
 175         struct wpa_ctrl *ctrl;
 176         char buf[128];
 177         size_t len;
 178
 179         ctrl = os_malloc(sizeof(*ctrl));
 180         if (ctrl == NULL)
 181                 return NULL;
 182         os_memset(ctrl, 0, sizeof(*ctrl));
 183
 184         ctrl->s = socket(PF_INET, SOCK_DGRAM, 0);
 185         if (ctrl->s < 0) {
 186                 perror("socket");
 187                 os_free(ctrl);
 188                 return NULL;
 189         }
 190
 191         ctrl->local.sin_family = AF_INET;
 192         ctrl->local.sin_addr.s_addr = htonl((127 << 24) | 1);
 193         if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
 194                  sizeof(ctrl->local)) < 0) {
 195                 close(ctrl->s);
 196                 os_free(ctrl);
 197                 return NULL;
 198         }
 199
 200         ctrl->dest.sin_family = AF_INET;
 201         ctrl->dest.sin_addr.s_addr = htonl((127 << 24) | 1);
 202         ctrl->dest.sin_port = htons(WPA_CTRL_IFACE_PORT);
 203         if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
 204                     sizeof(ctrl->dest)) < 0) {
 205                 perror("connect");
 206                 close(ctrl->s);
 207                 os_free(ctrl);
 208                 return NULL;
 209         }
 210
 211         len = sizeof(buf) - 1;
 212         if (wpa_ctrl_request(ctrl, "GET_COOKIE", 10, buf, &len, NULL) == 0) {
 213                 buf[len] = '\0';
 214                 ctrl->cookie = os_strdup(buf);
 215         }
 216
 217         return ctrl;
 218 }
 219
 220
 221 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 222 {
 223         close(ctrl->s);
 224         os_free(ctrl->cookie);
 225         os_free(ctrl);
 226 }
 227
 228 #endif /* CONFIG_CTRL_IFACE_UDP */
 229
 230
 231 #ifdef CTRL_IFACE_SOCKET
 232 int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
 233                      char *reply, size_t *reply_len,
 234                      void (*msg_cb)(char *msg, size_t len))
 235 {
 236         struct timeval tv;
 237         int res;
 238         fd_set rfds;
 239         const char *_cmd;
 240         char *cmd_buf = NULL;
 241         size_t _cmd_len;
 242
 243 #ifdef CONFIG_CTRL_IFACE_UDP
 244         if (ctrl->cookie) {
 245                 char *pos;
 246                 _cmd_len = os_strlen(ctrl->cookie) + 1 + cmd_len;
 247                 cmd_buf = os_malloc(_cmd_len);
 248                 if (cmd_buf == NULL)
 249                         return -1;
 250                 _cmd = cmd_buf;
 251                 pos = cmd_buf;
 252                 os_strlcpy(pos, ctrl->cookie, _cmd_len);
 253                 pos += os_strlen(ctrl->cookie);
 254                 *pos++ = ' ';
 255                 os_memcpy(pos, cmd, cmd_len);
 256         } else
 257 #endif /* CONFIG_CTRL_IFACE_UDP */
 258         {
 259                 _cmd = cmd;
 260                 _cmd_len = cmd_len;
 261         }
 262
 263         if (send(ctrl->s, _cmd, _cmd_len, 0) < 0) {
 264                 os_free(cmd_buf);
 265                 return -1;
 266         }
 267         os_free(cmd_buf);
 268
 269         for (;;) {
 270                 tv.tv_sec = 10;
 271                 tv.tv_usec = 0;
 272                 FD_ZERO(&rfds);
 273                 FD_SET(ctrl->s, &rfds);
 274                 res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
 275                 if (FD_ISSET(ctrl->s, &rfds)) {
 276                         res = recv(ctrl->s, reply, *reply_len, 0);
 277                         if (res < 0)
 278                                 return res;
 279                         if (res > 0 && reply[0] == '<') {
 280                                 /* This is an unsolicited message from
 281                                  * wpa_supplicant, not the reply to the
 282                                  * request. Use msg_cb to report this to the
 283                                  * caller. */
 284                                 if (msg_cb) {
 285                                         /* Make sure the message is nul
 286                                          * terminated. */
 287                                         if ((size_t) res == *reply_len)
 288                                                 res = (*reply_len) - 1;
 289                                         reply[res] = '\0';
 290                                         msg_cb(reply, res);
 291                                 }
 292                                 continue;
 293                         }
 294                         *reply_len = res;
 295                         break;
 296                 } else {
 297                         return -2;
 298                 }
 299         }
 300         return 0;
 301 }
 302 #endif /* CTRL_IFACE_SOCKET */
 303
 304
 305 static int wpa_ctrl_attach_helper(struct wpa_ctrl *ctrl, int attach)
 306 {
 307         char buf[10];
 308         int ret;
 309         size_t len = 10;
 310
 311         ret = wpa_ctrl_request(ctrl, attach ? "ATTACH" : "DETACH", 6,
 312                                buf, &len, NULL);
 313         if (ret < 0)
 314                 return ret;
 315         if (len == 3 && os_memcmp(buf, "OK\n", 3) == 0)
 316                 return 0;
 317         return -1;
 318 }
 319
 320
 321 int wpa_ctrl_attach(struct wpa_ctrl *ctrl)
 322 {
 323         return wpa_ctrl_attach_helper(ctrl, 1);
 324 }
 325
 326
 327 int wpa_ctrl_detach(struct wpa_ctrl *ctrl)
 328 {
 329         return wpa_ctrl_attach_helper(ctrl, 0);
 330 }
 331
 332
 333 #ifdef CTRL_IFACE_SOCKET
 334
 335 int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
 336 {
 337         int res;
 338
 339         res = recv(ctrl->s, reply, *reply_len, 0);
 340         if (res < 0)
 341                 return res;
 342         *reply_len = res;
 343         return 0;
 344 }
 345
 346
 347 int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
 348 {
 349         struct timeval tv;
 350         fd_set rfds;
 351         tv.tv_sec = 0;
 352         tv.tv_usec = 0;
 353         FD_ZERO(&rfds);
 354         FD_SET(ctrl->s, &rfds);
 355         select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
 356         return FD_ISSET(ctrl->s, &rfds);
 357 }
 358
 359
 360 int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
 361 {
 362         return ctrl->s;
 363 }
 364
 365 #endif /* CTRL_IFACE_SOCKET */
 366
 367
 368 #ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
 369
 370 #ifndef WPA_SUPPLICANT_NAMED_PIPE
 371 #define WPA_SUPPLICANT_NAMED_PIPE "WpaSupplicant"
 372 #endif
 373 #define NAMED_PIPE_PREFIX TEXT("\\\\.\\pipe\\") TEXT(WPA_SUPPLICANT_NAMED_PIPE)
 374
 375 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
 376 {
 377         struct wpa_ctrl *ctrl;
 378         DWORD mode;
 379         TCHAR name[256];
 380         int i, ret;
 381
 382         ctrl = os_malloc(sizeof(*ctrl));
 383         if (ctrl == NULL)
 384                 return NULL;
 385         os_memset(ctrl, 0, sizeof(*ctrl));
 386
 387 #ifdef UNICODE
 388         if (ctrl_path == NULL)
 389                 ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX);
 390         else
 391                 ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX TEXT("-%S"),
 392                                  ctrl_path);
 393 #else /* UNICODE */
 394         if (ctrl_path == NULL)
 395                 ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX);
 396         else
 397                 ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX "-%s",
 398                                   ctrl_path);
 399 #endif /* UNICODE */
 400         if (ret < 0 || ret >= 256) {
 401                 os_free(ctrl);
 402                 return NULL;
 403         }
 404
 405         for (i = 0; i < 10; i++) {
 406                 ctrl->pipe = CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0,
 407                                         NULL, OPEN_EXISTING, 0, NULL);
 408                 /*
 409                  * Current named pipe server side in wpa_supplicant is
 410                  * re-opening the pipe for new clients only after the previous
 411                  * one is taken into use. This leaves a small window for race
 412                  * conditions when two connections are being opened at almost
 413                  * the same time. Retry if that was the case.
 414                  */
 415                 if (ctrl->pipe != INVALID_HANDLE_VALUE ||
 416                     GetLastError() != ERROR_PIPE_BUSY)
 417                         break;
 418                 WaitNamedPipe(name, 1000);
 419         }
 420         if (ctrl->pipe == INVALID_HANDLE_VALUE) {
 421                 os_free(ctrl);
 422                 return NULL;
 423         }
 424
 425         mode = PIPE_READMODE_MESSAGE;
 426         if (!SetNamedPipeHandleState(ctrl->pipe, &mode, NULL, NULL)) {
 427                 CloseHandle(ctrl->pipe);
 428                 os_free(ctrl);
 429                 return NULL;
 430         }
 431
 432         return ctrl;
 433 }
 434
 435
 436 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 437 {
 438         CloseHandle(ctrl->pipe);
 439         os_free(ctrl);
 440 }
 441
 442
 443 int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
 444                      char *reply, size_t *reply_len,
 445                      void (*msg_cb)(char *msg, size_t len))
 446 {
 447         DWORD written;
 448         DWORD readlen = *reply_len;
 449
 450         if (!WriteFile(ctrl->pipe, cmd, cmd_len, &written, NULL))
 451                 return -1;
 452
 453         if (!ReadFile(ctrl->pipe, reply, *reply_len, &readlen, NULL))
 454                 return -1;
 455         *reply_len = readlen;
 456
 457         return 0;
 458 }
 459
 460
 461 int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
 462 {
 463         DWORD len = *reply_len;
 464         if (!ReadFile(ctrl->pipe, reply, *reply_len, &len, NULL))
 465                 return -1;
 466         *reply_len = len;
 467         return 0;
 468 }
 469
 470
 471 int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
 472 {
 473         DWORD left;
 474
 475         if (!PeekNamedPipe(ctrl->pipe, NULL, 0, NULL, &left, NULL))
 476                 return -1;
 477         return left ? 1 : 0;
 478 }
 479
 480
 481 int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
 482 {
 483         return -1;
 484 }
 485
 486 #endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
 487
 488 #endif /* CONFIG_CTRL_IFACE */