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 #ifdef ANDROID
  23 #include <dirent.h>
  24 #include <linux/limits.h>
  25 #include <cutils/sockets.h>
  26 #include <cutils/memory.h>
  27 #include "private/android_filesystem_config.h"
  28 #endif
  29
  30 #include "wpa_ctrl.h"
  31 #include "common.h"
  32
  33
  34 #if defined(CONFIG_CTRL_IFACE_UNIX) || defined(CONFIG_CTRL_IFACE_UDP)
  35 #define CTRL_IFACE_SOCKET
  36 #ifdef ANDROID
  37 static const char *local_socket_dir = "/data/misc/wifi/sockets";
  38 static const char *local_socket_prefix = "wpa_ctrl_";
  39 #endif /* ANDROID */
  40 #endif /* CONFIG_CTRL_IFACE_UNIX || CONFIG_CTRL_IFACE_UDP */
  41
  42 /**
  43  * struct wpa_ctrl - Internal structure for control interface library
  44  *
  45  * This structure is used by the wpa_supplicant/hostapd control interface
  46  * library to store internal data. Programs using the library should not touch
  47  * this data directly. They can only use the pointer to the data structure as
  48  * an identifier for the control interface connection and use this as one of
  49  * the arguments for most of the control interface library functions.
  50  */
  51 struct wpa_ctrl {
  52 #ifdef CONFIG_CTRL_IFACE_UDP
  53         int s;
  54         struct sockaddr_in local;
  55         struct sockaddr_in dest;
  56         char *cookie;
  57 #endif /* CONFIG_CTRL_IFACE_UDP */
  58 #ifdef CONFIG_CTRL_IFACE_UNIX
  59         int s;
  60         struct sockaddr_un local;
  61         struct sockaddr_un dest;
  62 #endif /* CONFIG_CTRL_IFACE_UNIX */
  63 #ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
  64         HANDLE pipe;
  65 #endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
  66 };
  67
  68
  69 #ifdef CONFIG_CTRL_IFACE_UNIX
  70
  71 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
  72 {
  73         struct wpa_ctrl *ctrl;
  74         static int counter = 0;
  75
  76         ctrl = os_malloc(sizeof(*ctrl));
  77         if (ctrl == NULL)
  78                 return NULL;
  79         os_memset(ctrl, 0, sizeof(*ctrl));
  80
  81         ctrl->s = socket(PF_UNIX, SOCK_DGRAM, 0);
  82         if (ctrl->s < 0) {
  83                 os_free(ctrl);
  84                 return NULL;
  85         }
  86
  87         ctrl->local.sun_family = AF_UNIX;
  88         os_snprintf(ctrl->local.sun_path, sizeof(ctrl->local.sun_path),
  89 #ifdef ANDROID
  90                     "%s/%s%d-%d", local_socket_dir, local_socket_prefix,
  91                     getpid(), counter++);
  92 #else /* ANDROID */
  93                     "/tmp/wpa_ctrl_%d-%d", getpid(), counter++);
  94 #endif
  95         if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
  96                     sizeof(ctrl->local)) < 0) {
  97                 close(ctrl->s);
  98                 os_free(ctrl);
  99                 return NULL;
 100         }
 101
 102 #ifdef ANDROID
 103         chmod(ctrl->local.sun_path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP);
 104         chown(ctrl->local.sun_path, AID_SYSTEM, AID_WIFI);
 105         /*
 106          * If the ctrl_path isn't an absolute pathname, assume that
 107          * it's the name of a socket in the Android reserved namespace.
 108          * Otherwise, it's a normal UNIX domain socket appearing in the
 109          * filesystem.
 110          */
 111         if (ctrl_path != NULL && *ctrl_path != '/') {
 112                 os_snprintf(ctrl->dest.sun_path, sizeof(ctrl->dest.sun_path), "wpa_%s",
 113                             ctrl_path);
 114                 if (socket_local_client_connect(ctrl->s,
 115                                                 ctrl->dest.sun_path,
 116                                                 ANDROID_SOCKET_NAMESPACE_RESERVED,
 117                                                 SOCK_DGRAM) < 0) {
 118                         close(ctrl->s);
 119                         unlink(ctrl->local.sun_path);
 120                         os_free(ctrl);
 121                         return NULL;
 122                 }
 123                 return ctrl;
 124         }
 125 #endif
 126         ctrl->dest.sun_family = AF_UNIX;
 127         os_snprintf(ctrl->dest.sun_path, sizeof(ctrl->dest.sun_path), "%s",
 128                     ctrl_path);
 129         if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
 130                     sizeof(ctrl->dest)) < 0) {
 131                 close(ctrl->s);
 132                 unlink(ctrl->local.sun_path);
 133                 os_free(ctrl);
 134                 return NULL;
 135         }
 136
 137         return ctrl;
 138 }
 139
 140
 141 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 142 {
 143         unlink(ctrl->local.sun_path);
 144         close(ctrl->s);
 145         os_free(ctrl);
 146 }
 147
 148 #ifdef ANDROID
 149 /**
 150  * wpa_ctrl_cleanup() - Delete any local UNIX domain socket files that
 151  * may be left over from clients that were previously connected to
 152  * wpa_supplicant. This keeps these files from being orphaned in the
 153  * event of crashes that prevented them from being removed as part
 154  * of the normal orderly shutdown.
 155  */
 156 void wpa_ctrl_cleanup()
 157 {
 158     DIR *dir;
 159     struct dirent entry;
 160     struct dirent *result;
 161     size_t dirnamelen;
 162     int prefixlen = strlen(local_socket_prefix);
 163     size_t maxcopy;
 164     char pathname[PATH_MAX];
 165     char *namep;
 166
 167     if ((dir = opendir(local_socket_dir)) == NULL)
 168         return;
 169
 170     dirnamelen = (size_t)snprintf(pathname, sizeof(pathname), "%s/", local_socket_dir);
 171     if (dirnamelen >= sizeof(pathname)) {
 172         closedir(dir);
 173         return;
 174     }
 175     namep = pathname + dirnamelen;
 176     maxcopy = PATH_MAX-dirnamelen;
 177     while (readdir_r(dir, &entry, &result) == 0 && result != NULL) {
 178         if (strncmp(entry.d_name, local_socket_prefix, prefixlen) == 0) {
 179             if (strlcpy(namep, entry.d_name, maxcopy) < maxcopy) {
 180                 unlink(pathname);
 181             }
 182         }
 183     }
 184     closedir(dir);
 185 }
 186 #endif /* ANDROID */
 187
 188 #else /* CONFIG_CTRL_IFACE_UNIX */
 189 #ifdef ANDROID
 190 void wpa_ctrl_cleanup()
 191 {
 192 }
 193 #endif /* ANDROID */
 194 #endif /* CONFIG_CTRL_IFACE_UNIX */
 195
 196 #ifdef CONFIG_CTRL_IFACE_UDP
 197
 198 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
 199 {
 200         struct wpa_ctrl *ctrl;
 201         char buf[128];
 202         size_t len;
 203
 204         ctrl = os_malloc(sizeof(*ctrl));
 205         if (ctrl == NULL)
 206                 return NULL;
 207         os_memset(ctrl, 0, sizeof(*ctrl));
 208
 209         ctrl->s = socket(PF_INET, SOCK_DGRAM, 0);
 210         if (ctrl->s < 0) {
 211                 perror("socket");
 212                 os_free(ctrl);
 213                 return NULL;
 214         }
 215
 216         ctrl->local.sin_family = AF_INET;
 217         ctrl->local.sin_addr.s_addr = htonl((127 << 24) | 1);
 218         if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
 219                  sizeof(ctrl->local)) < 0) {
 220                 close(ctrl->s);
 221                 os_free(ctrl);
 222                 return NULL;
 223         }
 224
 225         ctrl->dest.sin_family = AF_INET;
 226         ctrl->dest.sin_addr.s_addr = htonl((127 << 24) | 1);
 227         ctrl->dest.sin_port = htons(WPA_CTRL_IFACE_PORT);
 228         if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
 229                     sizeof(ctrl->dest)) < 0) {
 230                 perror("connect");
 231                 close(ctrl->s);
 232                 os_free(ctrl);
 233                 return NULL;
 234         }
 235
 236         len = sizeof(buf) - 1;
 237         if (wpa_ctrl_request(ctrl, "GET_COOKIE", 10, buf, &len, NULL) == 0) {
 238                 buf[len] = '\0';
 239                 ctrl->cookie = strdup(buf);
 240         }
 241
 242         return ctrl;
 243 }
 244
 245
 246 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 247 {
 248         close(ctrl->s);
 249         os_free(ctrl->cookie);
 250         os_free(ctrl);
 251 }
 252
 253 #endif /* CONFIG_CTRL_IFACE_UDP */
 254
 255
 256 #ifdef CTRL_IFACE_SOCKET
 257 int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
 258                      char *reply, size_t *reply_len,
 259                      void (*msg_cb)(char *msg, size_t len))
 260 {
 261         struct timeval tv;
 262         int res;
 263         fd_set rfds;
 264         const char *_cmd;
 265         char *cmd_buf = NULL;
 266         size_t _cmd_len;
 267
 268 #ifdef CONFIG_CTRL_IFACE_UDP
 269         if (ctrl->cookie) {
 270                 char *pos;
 271                 _cmd_len = strlen(ctrl->cookie) + 1 + cmd_len;
 272                 cmd_buf = os_malloc(_cmd_len );
 273                 if (cmd_buf == NULL)
 274                         return -1;
 275                 _cmd = cmd_buf;
 276                 pos = cmd_buf;
 277                 strcpy(pos, ctrl->cookie);
 278                 pos += strlen(ctrl->cookie);
 279                 *pos++ = ' ';
 280                 memcpy(pos, cmd, cmd_len);
 281         } else
 282 #endif /* CONFIG_CTRL_IFACE_UDP */
 283         {
 284                 _cmd = cmd;
 285                 _cmd_len = cmd_len;
 286         }
 287
 288         if (send(ctrl->s, _cmd, _cmd_len, 0) < 0) {
 289                 os_free(cmd_buf);
 290                 return -1;
 291         }
 292         os_free(cmd_buf);
 293
 294         for (;;) {
 295                 tv.tv_sec = 2;
 296                 tv.tv_usec = 0;
 297                 FD_ZERO(&rfds);
 298                 FD_SET(ctrl->s, &rfds);
 299                 res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
 300                 if (FD_ISSET(ctrl->s, &rfds)) {
 301                         res = recv(ctrl->s, reply, *reply_len, 0);
 302                         if (res < 0)
 303                                 return res;
 304                         if (res > 0 && reply[0] == '<') {
 305                                 /* This is an unsolicited message from
 306                                  * wpa_supplicant, not the reply to the
 307                                  * request. Use msg_cb to report this to the
 308                                  * caller. */
 309                                 if (msg_cb) {
 310                                         /* Make sure the message is nul
 311                                          * terminated. */
 312                                         if ((size_t) res == *reply_len)
 313                                                 res = (*reply_len) - 1;
 314                                         reply[res] = '\0';
 315                                         msg_cb(reply, res);
 316                                 }
 317                                 continue;
 318                         }
 319                         *reply_len = res;
 320                         break;
 321                 } else {
 322                         return -2;
 323                 }
 324         }
 325         return 0;
 326 }
 327 #endif /* CTRL_IFACE_SOCKET */
 328
 329
 330 static int wpa_ctrl_attach_helper(struct wpa_ctrl *ctrl, int attach)
 331 {
 332         char buf[10];
 333         int ret;
 334         size_t len = 10;
 335
 336         ret = wpa_ctrl_request(ctrl, attach ? "ATTACH" : "DETACH", 6,
 337                                buf, &len, NULL);
 338         if (ret < 0)
 339                 return ret;
 340         if (len == 3 && os_memcmp(buf, "OK\n", 3) == 0)
 341                 return 0;
 342         return -1;
 343 }
 344
 345
 346 int wpa_ctrl_attach(struct wpa_ctrl *ctrl)
 347 {
 348         return wpa_ctrl_attach_helper(ctrl, 1);
 349 }
 350
 351
 352 int wpa_ctrl_detach(struct wpa_ctrl *ctrl)
 353 {
 354         return wpa_ctrl_attach_helper(ctrl, 0);
 355 }
 356
 357
 358 #ifdef CTRL_IFACE_SOCKET
 359
 360 int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
 361 {
 362         int res;
 363
 364         res = recv(ctrl->s, reply, *reply_len, 0);
 365         if (res < 0)
 366                 return res;
 367         *reply_len = res;
 368         return 0;
 369 }
 370
 371
 372 int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
 373 {
 374         struct timeval tv;
 375         fd_set rfds;
 376         tv.tv_sec = 0;
 377         tv.tv_usec = 0;
 378         FD_ZERO(&rfds);
 379         FD_SET(ctrl->s, &rfds);
 380         select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
 381         return FD_ISSET(ctrl->s, &rfds);
 382 }
 383
 384
 385 int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
 386 {
 387         return ctrl->s;
 388 }
 389
 390 #endif /* CTRL_IFACE_SOCKET */
 391
 392
 393 #ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
 394
 395 #ifndef WPA_SUPPLICANT_NAMED_PIPE
 396 #define WPA_SUPPLICANT_NAMED_PIPE "WpaSupplicant"
 397 #endif
 398 #define NAMED_PIPE_PREFIX TEXT("\\\\.\\pipe\\") TEXT(WPA_SUPPLICANT_NAMED_PIPE)
 399
 400 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
 401 {
 402         struct wpa_ctrl *ctrl;
 403         DWORD mode;
 404         TCHAR name[256];
 405         int i;
 406
 407         ctrl = os_malloc(sizeof(*ctrl));
 408         if (ctrl == NULL)
 409                 return NULL;
 410         os_memset(ctrl, 0, sizeof(*ctrl));
 411
 412 #ifdef UNICODE
 413         if (ctrl_path == NULL)
 414                 _snwprintf(name, 256, NAMED_PIPE_PREFIX);
 415         else
 416                 _snwprintf(name, 256, NAMED_PIPE_PREFIX TEXT("-%S"),
 417                            ctrl_path);
 418 #else /* UNICODE */
 419         if (ctrl_path == NULL)
 420                 os_snprintf(name, 256, NAMED_PIPE_PREFIX);
 421         else
 422                 os_snprintf(name, 256, NAMED_PIPE_PREFIX "-%s",
 423                             ctrl_path);
 424 #endif /* UNICODE */
 425
 426         for (i = 0; i < 10; i++) {
 427                 ctrl->pipe = CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0,
 428                                         NULL, OPEN_EXISTING, 0, NULL);
 429                 /*
 430                  * Current named pipe server side in wpa_supplicant is
 431                  * re-opening the pipe for new clients only after the previous
 432                  * one is taken into use. This leaves a small window for race
 433                  * conditions when two connections are being opened at almost
 434                  * the same time. Retry if that was the case.
 435                  */
 436                 if (ctrl->pipe != INVALID_HANDLE_VALUE ||
 437                     GetLastError() != ERROR_PIPE_BUSY)
 438                         break;
 439                 WaitNamedPipe(name, 1000);
 440         }
 441         if (ctrl->pipe == INVALID_HANDLE_VALUE) {
 442                 os_free(ctrl);
 443                 return NULL;
 444         }
 445
 446         mode = PIPE_READMODE_MESSAGE;
 447         if (!SetNamedPipeHandleState(ctrl->pipe, &mode, NULL, NULL)) {
 448                 CloseHandle(ctrl->pipe);
 449                 os_free(ctrl);
 450                 return NULL;
 451         }
 452
 453         return ctrl;
 454 }
 455
 456
 457 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 458 {
 459         CloseHandle(ctrl->pipe);
 460         os_free(ctrl);
 461 }
 462
 463
 464 int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
 465                      char *reply, size_t *reply_len,
 466                      void (*msg_cb)(char *msg, size_t len))
 467 {
 468         DWORD written;
 469         DWORD readlen = *reply_len;
 470
 471         if (!WriteFile(ctrl->pipe, cmd, cmd_len, &written, NULL))
 472                 return -1;
 473
 474         if (!ReadFile(ctrl->pipe, reply, *reply_len, &readlen, NULL))
 475                 return -1;
 476         *reply_len = readlen;
 477
 478         return 0;
 479 }
 480
 481
 482 int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
 483 {
 484         DWORD len = *reply_len;
 485         if (!ReadFile(ctrl->pipe, reply, *reply_len, &len, NULL))
 486                 return -1;
 487         *reply_len = len;
 488         return 0;
 489 }
 490
 491
 492 int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
 493 {
 494         DWORD left;
 495
 496         if (!PeekNamedPipe(ctrl->pipe, NULL, 0, NULL, &left, NULL))
 497                 return -1;
 498         return left ? 1 : 0;
 499 }
 500
 501
 502 int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
 503 {
 504         return ctrl->pipe;
 505 }
 506
 507 #endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
 508
 509 #endif /* CONFIG_CTRL_IFACE */