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