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 software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #ifdef CONFIG_CTRL_IFACE
  12
  13 #ifdef CONFIG_CTRL_IFACE_UNIX
  14 #include <sys/un.h>
  15 #include <unistd.h>
  16 #include <fcntl.h>
  17 #endif /* CONFIG_CTRL_IFACE_UNIX */
  18
  19 #ifdef ANDROID
  20 #include <dirent.h>
  21 #include <cutils/sockets.h>
  22 #include "private/android_filesystem_config.h"
  23 #endif /* ANDROID */
  24
  25 #include "wpa_ctrl.h"
  26 #include "common.h"
  27
  28
  29 #if defined(CONFIG_CTRL_IFACE_UNIX) || defined(CONFIG_CTRL_IFACE_UDP)
  30 #define CTRL_IFACE_SOCKET
  31 #endif /* CONFIG_CTRL_IFACE_UNIX || CONFIG_CTRL_IFACE_UDP */
  32
  33
  34 /**
  35  * struct wpa_ctrl - Internal structure for control interface library
  36  *
  37  * This structure is used by the wpa_supplicant/hostapd control interface
  38  * library to store internal data. Programs using the library should not touch
  39  * this data directly. They can only use the pointer to the data structure as
  40  * an identifier for the control interface connection and use this as one of
  41  * the arguments for most of the control interface library functions.
  42  */
  43 struct wpa_ctrl {
  44 #ifdef CONFIG_CTRL_IFACE_UDP
  45         int s;
  46         struct sockaddr_in local;
  47         struct sockaddr_in dest;
  48         char *cookie;
  49 #endif /* CONFIG_CTRL_IFACE_UDP */
  50 #ifdef CONFIG_CTRL_IFACE_UNIX
  51         int s;
  52         struct sockaddr_un local;
  53         struct sockaddr_un dest;
  54 #endif /* CONFIG_CTRL_IFACE_UNIX */
  55 #ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
  56         HANDLE pipe;
  57 #endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
  58 };
  59
  60
  61 #ifdef CONFIG_CTRL_IFACE_UNIX
  62
  63 #ifndef CONFIG_CTRL_IFACE_CLIENT_DIR
  64 #define CONFIG_CTRL_IFACE_CLIENT_DIR "/tmp"
  65 #endif /* CONFIG_CTRL_IFACE_CLIENT_DIR */
  66 #ifndef CONFIG_CTRL_IFACE_CLIENT_PREFIX
  67 #define CONFIG_CTRL_IFACE_CLIENT_PREFIX "wpa_ctrl_"
  68 #endif /* CONFIG_CTRL_IFACE_CLIENT_PREFIX */
  69
  70
  71 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
  72 {
  73         struct wpa_ctrl *ctrl;
  74         static int counter = 0;
  75         int ret;
  76         size_t res;
  77         int tries = 0;
  78         int flags;
  79
  80         ctrl = os_malloc(sizeof(*ctrl));
  81         if (ctrl == NULL)
  82                 return NULL;
  83         os_memset(ctrl, 0, sizeof(*ctrl));
  84
  85         ctrl->s = socket(PF_UNIX, SOCK_DGRAM, 0);
  86         if (ctrl->s < 0) {
  87                 os_free(ctrl);
  88                 return NULL;
  89         }
  90
  91         ctrl->local.sun_family = AF_UNIX;
  92         counter++;
  93 try_again:
  94         ret = os_snprintf(ctrl->local.sun_path, sizeof(ctrl->local.sun_path),
  95                           CONFIG_CTRL_IFACE_CLIENT_DIR "/"
  96                           CONFIG_CTRL_IFACE_CLIENT_PREFIX "%d-%d",
  97                           (int) getpid(), counter);
  98         if (ret < 0 || (size_t) ret >= sizeof(ctrl->local.sun_path)) {
  99                 close(ctrl->s);
 100                 os_free(ctrl);
 101                 return NULL;
 102         }
 103         tries++;
 104         if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
 105                     sizeof(ctrl->local)) < 0) {
 106                 if (errno == EADDRINUSE && tries < 2) {
 107                         /*
 108                          * getpid() returns unique identifier for this instance
 109                          * of wpa_ctrl, so the existing socket file must have
 110                          * been left by unclean termination of an earlier run.
 111                          * Remove the file and try again.
 112                          */
 113                         unlink(ctrl->local.sun_path);
 114                         goto try_again;
 115                 }
 116                 close(ctrl->s);
 117                 os_free(ctrl);
 118                 return NULL;
 119         }
 120
 121 #ifdef ANDROID
 122         chmod(ctrl->local.sun_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 123         chown(ctrl->local.sun_path, AID_SYSTEM, AID_WIFI);
 124         /*
 125          * If the ctrl_path isn't an absolute pathname, assume that
 126          * it's the name of a socket in the Android reserved namespace.
 127          * Otherwise, it's a normal UNIX domain socket appearing in the
 128          * filesystem.
 129          */
 130         if (ctrl_path != NULL && *ctrl_path != '/') {
 131                 char buf[21];
 132                 os_snprintf(buf, sizeof(buf), "wpa_%s", ctrl_path);
 133                 if (socket_local_client_connect(
 134                             ctrl->s, buf,
 135                             ANDROID_SOCKET_NAMESPACE_RESERVED,
 136                             SOCK_DGRAM) < 0) {
 137                         close(ctrl->s);
 138                         unlink(ctrl->local.sun_path);
 139                         os_free(ctrl);
 140                         return NULL;
 141                 }
 142                 return ctrl;
 143         }
 144 #endif /* ANDROID */
 145
 146         ctrl->dest.sun_family = AF_UNIX;
 147         res = os_strlcpy(ctrl->dest.sun_path, ctrl_path,
 148                          sizeof(ctrl->dest.sun_path));
 149         if (res >= sizeof(ctrl->dest.sun_path)) {
 150                 close(ctrl->s);
 151                 os_free(ctrl);
 152                 return NULL;
 153         }
 154         if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
 155                     sizeof(ctrl->dest)) < 0) {
 156                 close(ctrl->s);
 157                 unlink(ctrl->local.sun_path);
 158                 os_free(ctrl);
 159                 return NULL;
 160         }
 161
 162         /*
 163          * Make socket non-blocking so that we don't hang forever if
 164          * target dies unexpectedly.
 165          */
 166         flags = fcntl(ctrl->s, F_GETFL);
 167         if (flags >= 0) {
 168                 flags |= O_NONBLOCK;
 169                 if (fcntl(ctrl->s, F_SETFL, flags) < 0) {
 170                         perror("fcntl(ctrl->s, O_NONBLOCK)");
 171                         /* Not fatal, continue on.*/
 172                 }
 173         }
 174
 175         return ctrl;
 176 }
 177
 178
 179 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 180 {
 181         if (ctrl == NULL)
 182                 return;
 183         unlink(ctrl->local.sun_path);
 184         if (ctrl->s >= 0)
 185                 close(ctrl->s);
 186         os_free(ctrl);
 187 }
 188
 189
 190 #ifdef ANDROID
 191 /**
 192  * wpa_ctrl_cleanup() - Delete any local UNIX domain socket files that
 193  * may be left over from clients that were previously connected to
 194  * wpa_supplicant. This keeps these files from being orphaned in the
 195  * event of crashes that prevented them from being removed as part
 196  * of the normal orderly shutdown.
 197  */
 198 void wpa_ctrl_cleanup(void)
 199 {
 200         DIR *dir;
 201         struct dirent entry;
 202         struct dirent *result;
 203         size_t dirnamelen;
 204         int prefixlen = os_strlen(CONFIG_CTRL_IFACE_CLIENT_PREFIX);
 205         size_t maxcopy;
 206         char pathname[PATH_MAX];
 207         char *namep;
 208
 209         if ((dir = opendir(CONFIG_CTRL_IFACE_CLIENT_DIR)) == NULL)
 210                 return;
 211
 212         dirnamelen = (size_t) os_snprintf(pathname, sizeof(pathname), "%s/",
 213                                           CONFIG_CTRL_IFACE_CLIENT_DIR);
 214         if (dirnamelen >= sizeof(pathname)) {
 215                 closedir(dir);
 216                 return;
 217         }
 218         namep = pathname + dirnamelen;
 219         maxcopy = PATH_MAX - dirnamelen;
 220         while (readdir_r(dir, &entry, &result) == 0 && result != NULL) {
 221                 if (os_strncmp(entry.d_name, CONFIG_CTRL_IFACE_CLIENT_PREFIX,
 222                                prefixlen) == 0) {
 223                         if (os_strlcpy(namep, entry.d_name, maxcopy) < maxcopy)
 224                                 unlink(pathname);
 225                 }
 226         }
 227         closedir(dir);
 228 }
 229 #endif /* ANDROID */
 230
 231 #else /* CONFIG_CTRL_IFACE_UNIX */
 232
 233 #ifdef ANDROID
 234 void wpa_ctrl_cleanup(void)
 235 {
 236 }
 237 #endif /* ANDROID */
 238
 239 #endif /* CONFIG_CTRL_IFACE_UNIX */
 240
 241
 242 #ifdef CONFIG_CTRL_IFACE_UDP
 243
 244 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
 245 {
 246         struct wpa_ctrl *ctrl;
 247         char buf[128];
 248         size_t len;
 249
 250         ctrl = os_malloc(sizeof(*ctrl));
 251         if (ctrl == NULL)
 252                 return NULL;
 253         os_memset(ctrl, 0, sizeof(*ctrl));
 254
 255         ctrl->s = socket(PF_INET, SOCK_DGRAM, 0);
 256         if (ctrl->s < 0) {
 257                 perror("socket");
 258                 os_free(ctrl);
 259                 return NULL;
 260         }
 261
 262         ctrl->local.sin_family = AF_INET;
 263         ctrl->local.sin_addr.s_addr = htonl((127 << 24) | 1);
 264         if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
 265                  sizeof(ctrl->local)) < 0) {
 266                 close(ctrl->s);
 267                 os_free(ctrl);
 268                 return NULL;
 269         }
 270
 271         ctrl->dest.sin_family = AF_INET;
 272         ctrl->dest.sin_addr.s_addr = htonl((127 << 24) | 1);
 273         ctrl->dest.sin_port = htons(WPA_CTRL_IFACE_PORT);
 274         if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
 275                     sizeof(ctrl->dest)) < 0) {
 276                 perror("connect");
 277                 close(ctrl->s);
 278                 os_free(ctrl);
 279                 return NULL;
 280         }
 281
 282         len = sizeof(buf) - 1;
 283         if (wpa_ctrl_request(ctrl, "GET_COOKIE", 10, buf, &len, NULL) == 0) {
 284                 buf[len] = '\0';
 285                 ctrl->cookie = os_strdup(buf);
 286         }
 287
 288         return ctrl;
 289 }
 290
 291
 292 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 293 {
 294         close(ctrl->s);
 295         os_free(ctrl->cookie);
 296         os_free(ctrl);
 297 }
 298
 299 #endif /* CONFIG_CTRL_IFACE_UDP */
 300
 301
 302 #ifdef CTRL_IFACE_SOCKET
 303 int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
 304                      char *reply, size_t *reply_len,
 305                      void (*msg_cb)(char *msg, size_t len))
 306 {
 307         struct timeval tv;
 308         struct os_time started_at;
 309         int res;
 310         fd_set rfds;
 311         const char *_cmd;
 312         char *cmd_buf = NULL;
 313         size_t _cmd_len;
 314
 315 #ifdef CONFIG_CTRL_IFACE_UDP
 316         if (ctrl->cookie) {
 317                 char *pos;
 318                 _cmd_len = os_strlen(ctrl->cookie) + 1 + cmd_len;
 319                 cmd_buf = os_malloc(_cmd_len);
 320                 if (cmd_buf == NULL)
 321                         return -1;
 322                 _cmd = cmd_buf;
 323                 pos = cmd_buf;
 324                 os_strlcpy(pos, ctrl->cookie, _cmd_len);
 325                 pos += os_strlen(ctrl->cookie);
 326                 *pos++ = ' ';
 327                 os_memcpy(pos, cmd, cmd_len);
 328         } else
 329 #endif /* CONFIG_CTRL_IFACE_UDP */
 330         {
 331                 _cmd = cmd;
 332                 _cmd_len = cmd_len;
 333         }
 334
 335         errno = 0;
 336         started_at.sec = 0;
 337         started_at.usec = 0;
 338 retry_send:
 339         if (send(ctrl->s, _cmd, _cmd_len, 0) < 0) {
 340                 if (errno == EAGAIN || errno == EBUSY || errno == EWOULDBLOCK)
 341                 {
 342                         /*
 343                          * Must be a non-blocking socket... Try for a bit
 344                          * longer before giving up.
 345                          */
 346                         if (started_at.sec == 0)
 347                                 os_get_time(&started_at);
 348                         else {
 349                                 struct os_time n;
 350                                 os_get_time(&n);
 351                                 /* Try for a few seconds. */
 352                                 if (n.sec > started_at.sec + 5)
 353                                         goto send_err;
 354                         }
 355                         os_sleep(1, 0);
 356                         goto retry_send;
 357                 }
 358         send_err:
 359                 os_free(cmd_buf);
 360                 return -1;
 361         }
 362         os_free(cmd_buf);
 363
 364         for (;;) {
 365                 tv.tv_sec = 10;
 366                 tv.tv_usec = 0;
 367                 FD_ZERO(&rfds);
 368                 FD_SET(ctrl->s, &rfds);
 369                 res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
 370                 if (res < 0)
 371                         return res;
 372                 if (FD_ISSET(ctrl->s, &rfds)) {
 373                         res = recv(ctrl->s, reply, *reply_len, 0);
 374                         if (res < 0)
 375                                 return res;
 376                         if (res > 0 && reply[0] == '<') {
 377                                 /* This is an unsolicited message from
 378                                  * wpa_supplicant, not the reply to the
 379                                  * request. Use msg_cb to report this to the
 380                                  * caller. */
 381                                 if (msg_cb) {
 382                                         /* Make sure the message is nul
 383                                          * terminated. */
 384                                         if ((size_t) res == *reply_len)
 385                                                 res = (*reply_len) - 1;
 386                                         reply[res] = '\0';
 387                                         msg_cb(reply, res);
 388                                 }
 389                                 continue;
 390                         }
 391                         *reply_len = res;
 392                         break;
 393                 } else {
 394                         return -2;
 395                 }
 396         }
 397         return 0;
 398 }
 399 #endif /* CTRL_IFACE_SOCKET */
 400
 401
 402 static int wpa_ctrl_attach_helper(struct wpa_ctrl *ctrl, int attach)
 403 {
 404         char buf[10];
 405         int ret;
 406         size_t len = 10;
 407
 408         ret = wpa_ctrl_request(ctrl, attach ? "ATTACH" : "DETACH", 6,
 409                                buf, &len, NULL);
 410         if (ret < 0)
 411                 return ret;
 412         if (len == 3 && os_memcmp(buf, "OK\n", 3) == 0)
 413                 return 0;
 414         return -1;
 415 }
 416
 417
 418 int wpa_ctrl_attach(struct wpa_ctrl *ctrl)
 419 {
 420         return wpa_ctrl_attach_helper(ctrl, 1);
 421 }
 422
 423
 424 int wpa_ctrl_detach(struct wpa_ctrl *ctrl)
 425 {
 426         return wpa_ctrl_attach_helper(ctrl, 0);
 427 }
 428
 429
 430 #ifdef CTRL_IFACE_SOCKET
 431
 432 int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
 433 {
 434         int res;
 435
 436         res = recv(ctrl->s, reply, *reply_len, 0);
 437         if (res < 0)
 438                 return res;
 439         *reply_len = res;
 440         return 0;
 441 }
 442
 443
 444 int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
 445 {
 446         struct timeval tv;
 447         fd_set rfds;
 448         tv.tv_sec = 0;
 449         tv.tv_usec = 0;
 450         FD_ZERO(&rfds);
 451         FD_SET(ctrl->s, &rfds);
 452         select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
 453         return FD_ISSET(ctrl->s, &rfds);
 454 }
 455
 456
 457 int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
 458 {
 459         return ctrl->s;
 460 }
 461
 462 #endif /* CTRL_IFACE_SOCKET */
 463
 464
 465 #ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
 466
 467 #ifndef WPA_SUPPLICANT_NAMED_PIPE
 468 #define WPA_SUPPLICANT_NAMED_PIPE "WpaSupplicant"
 469 #endif
 470 #define NAMED_PIPE_PREFIX TEXT("\\\\.\\pipe\\") TEXT(WPA_SUPPLICANT_NAMED_PIPE)
 471
 472 struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
 473 {
 474         struct wpa_ctrl *ctrl;
 475         DWORD mode;
 476         TCHAR name[256];
 477         int i, ret;
 478
 479         ctrl = os_malloc(sizeof(*ctrl));
 480         if (ctrl == NULL)
 481                 return NULL;
 482         os_memset(ctrl, 0, sizeof(*ctrl));
 483
 484 #ifdef UNICODE
 485         if (ctrl_path == NULL)
 486                 ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX);
 487         else
 488                 ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX TEXT("-%S"),
 489                                  ctrl_path);
 490 #else /* UNICODE */
 491         if (ctrl_path == NULL)
 492                 ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX);
 493         else
 494                 ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX "-%s",
 495                                   ctrl_path);
 496 #endif /* UNICODE */
 497         if (ret < 0 || ret >= 256) {
 498                 os_free(ctrl);
 499                 return NULL;
 500         }
 501
 502         for (i = 0; i < 10; i++) {
 503                 ctrl->pipe = CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0,
 504                                         NULL, OPEN_EXISTING, 0, NULL);
 505                 /*
 506                  * Current named pipe server side in wpa_supplicant is
 507                  * re-opening the pipe for new clients only after the previous
 508                  * one is taken into use. This leaves a small window for race
 509                  * conditions when two connections are being opened at almost
 510                  * the same time. Retry if that was the case.
 511                  */
 512                 if (ctrl->pipe != INVALID_HANDLE_VALUE ||
 513                     GetLastError() != ERROR_PIPE_BUSY)
 514                         break;
 515                 WaitNamedPipe(name, 1000);
 516         }
 517         if (ctrl->pipe == INVALID_HANDLE_VALUE) {
 518                 os_free(ctrl);
 519                 return NULL;
 520         }
 521
 522         mode = PIPE_READMODE_MESSAGE;
 523         if (!SetNamedPipeHandleState(ctrl->pipe, &mode, NULL, NULL)) {
 524                 CloseHandle(ctrl->pipe);
 525                 os_free(ctrl);
 526                 return NULL;
 527         }
 528
 529         return ctrl;
 530 }
 531
 532
 533 void wpa_ctrl_close(struct wpa_ctrl *ctrl)
 534 {
 535         CloseHandle(ctrl->pipe);
 536         os_free(ctrl);
 537 }
 538
 539
 540 int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
 541                      char *reply, size_t *reply_len,
 542                      void (*msg_cb)(char *msg, size_t len))
 543 {
 544         DWORD written;
 545         DWORD readlen = *reply_len;
 546
 547         if (!WriteFile(ctrl->pipe, cmd, cmd_len, &written, NULL))
 548                 return -1;
 549
 550         if (!ReadFile(ctrl->pipe, reply, *reply_len, &readlen, NULL))
 551                 return -1;
 552         *reply_len = readlen;
 553
 554         return 0;
 555 }
 556
 557
 558 int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
 559 {
 560         DWORD len = *reply_len;
 561         if (!ReadFile(ctrl->pipe, reply, *reply_len, &len, NULL))
 562                 return -1;
 563         *reply_len = len;
 564         return 0;
 565 }
 566
 567
 568 int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
 569 {
 570         DWORD left;
 571
 572         if (!PeekNamedPipe(ctrl->pipe, NULL, 0, NULL, &left, NULL))
 573                 return -1;
 574         return left ? 1 : 0;
 575 }
 576
 577
 578 int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
 579 {
 580         return -1;
 581 }
 582
 583 #endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
 584
 585 #endif /* CONFIG_CTRL_IFACE */