Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2009 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | /* A simple implementation of PPTP Network Server (RFC 2637) which only |
| 18 | * creates a single session. The following code only handles control packets. |
| 19 | * Data packets are handled by PPPoPNS driver which can be found in Android |
| 20 | * kernel tree. */ |
| 21 | |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 22 | #include <stdbool.h> |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 23 | #include <stdio.h> |
| 24 | #include <stdlib.h> |
| 25 | #include <string.h> |
| 26 | #include <errno.h> |
| 27 | #include <sys/types.h> |
| 28 | #include <sys/socket.h> |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 29 | #include <netdb.h> |
| 30 | #include <unistd.h> |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 31 | #include <arpa/inet.h> |
Chia-chi Yeh | 0f72585 | 2011-07-18 13:57:17 -0700 | [diff] [blame] | 32 | #include <linux/netdevice.h> |
| 33 | #include <linux/if_pppox.h> |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 34 | #include <linux/types.h> |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 35 | |
| 36 | #include "mtpd.h" |
| 37 | |
| 38 | enum pptp_message { |
| 39 | SCCRQ = 1, |
| 40 | SCCRP = 2, |
| 41 | STOPCCRQ = 3, |
| 42 | STOPCCRP = 4, |
| 43 | ECHORQ = 5, |
| 44 | ECHORP = 6, |
| 45 | OCRQ = 7, |
| 46 | OCRP = 8, |
| 47 | ICRQ = 9, |
| 48 | ICRP = 10, |
| 49 | ICCN = 11, |
| 50 | CCRQ = 12, |
| 51 | CDN = 13, |
| 52 | WEN = 14, |
| 53 | SLI = 15, |
| 54 | MESSAGE_MAX = 15, |
| 55 | }; |
| 56 | |
| 57 | static char *messages[] = { |
| 58 | NULL, "SCCRQ", "SCCRP", "STOPCCRQ", "STOPCCRP", "ECHORQ", "ECHORP", |
| 59 | "OCRQ", "OCRP", "ICRQ", "ICRP", "ICCN", "CCRQ", "CDN", "WEN", "SLI", |
| 60 | }; |
| 61 | |
| 62 | static uint8_t lengths[] = { |
| 63 | 0, 156, 156, 16, 16, 16, 20, 168, 32, 220, 24, 28, 16, 148, 40, 24, |
| 64 | }; |
| 65 | |
| 66 | #define CONTROL_MESSAGE htons(1) |
| 67 | #define MAGIC_COOKIE htonl(0x1A2B3C4D) |
| 68 | #define PROTOCOL_VERSION htons(0x0100) |
| 69 | |
| 70 | #define RESULT_OK 1 |
| 71 | #define RESULT_ERROR 2 |
| 72 | |
| 73 | /* Some implementation uses 0 instead of 1, so we allow both of them. */ |
| 74 | #define ESTABLISHED(result) (result <= 1) |
| 75 | |
| 76 | #define HEADER_SIZE 8 |
| 77 | #define MIN_MESSAGE_SIZE 10 |
| 78 | |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 79 | static __be16 local; |
| 80 | static __be16 remote; |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 81 | static uint16_t state; |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 82 | static const char *remote_name; /* server host name or IP address */ |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 83 | |
| 84 | #define MAX_PACKET_LENGTH 220 |
| 85 | |
| 86 | /* We define all the fields we used in this structure. Type conversion and byte |
| 87 | * alignment are solved in one place. Although it looks a little bit ugly, it |
| 88 | * really makes life easier. */ |
| 89 | static struct packet { |
| 90 | int length; |
| 91 | int expect; |
| 92 | union { |
| 93 | uint8_t buffer[MAX_PACKET_LENGTH]; |
| 94 | struct { |
| 95 | struct __attribute__((packed)) { |
| 96 | uint16_t length; |
| 97 | uint16_t type; |
| 98 | uint32_t cookie; |
| 99 | } header; |
| 100 | uint16_t message; |
| 101 | uint16_t reserved; |
| 102 | union { |
| 103 | struct __attribute__((packed)) { |
| 104 | uint16_t protocol_version; |
| 105 | uint8_t result; |
| 106 | uint8_t error; |
| 107 | uint32_t framing; |
| 108 | uint32_t bearer; |
| 109 | uint16_t channels; |
| 110 | uint16_t firmware_revision; |
| 111 | char host[64]; |
| 112 | } sccrp, sccrq; |
| 113 | struct __attribute__((packed)) { |
| 114 | uint16_t call; |
| 115 | uint16_t serial; |
| 116 | uint32_t minimum_speed; |
| 117 | uint32_t maximum_speed; |
| 118 | uint32_t bearer; |
| 119 | uint32_t framing; |
| 120 | uint16_t window_size; |
| 121 | } ocrq; |
| 122 | struct __attribute__((packed)) { |
| 123 | uint16_t call; |
| 124 | uint16_t peer; |
| 125 | uint8_t result; |
| 126 | } ocrp, icrp; |
| 127 | struct __attribute__((packed)) { |
| 128 | uint32_t identifier; |
| 129 | uint8_t result; |
| 130 | } echorq, echorp; |
| 131 | struct __attribute__((packed)) { |
| 132 | uint16_t call; |
| 133 | } icrq, ccrq, cdn; |
| 134 | }; |
| 135 | } __attribute__((packed)); |
| 136 | } __attribute__((aligned(4))); |
| 137 | } incoming, outgoing; |
| 138 | |
| 139 | static void set_message(uint16_t message) |
| 140 | { |
| 141 | uint16_t length = lengths[message]; |
| 142 | memset(outgoing.buffer, 0, length); |
| 143 | outgoing.length = length; |
| 144 | outgoing.header.length = htons(length); |
| 145 | outgoing.header.type = CONTROL_MESSAGE; |
| 146 | outgoing.header.cookie = MAGIC_COOKIE; |
| 147 | outgoing.message = htons(message); |
| 148 | } |
| 149 | |
| 150 | static void send_packet() |
| 151 | { |
| 152 | send(the_socket, outgoing.buffer, outgoing.length, 0); |
| 153 | } |
| 154 | |
| 155 | static int recv_packet() |
| 156 | { |
| 157 | int length; |
| 158 | |
| 159 | /* We are going to read a new message if incoming.expect is 0. */ |
| 160 | if (!incoming.expect) { |
| 161 | incoming.length = 0; |
| 162 | incoming.expect = HEADER_SIZE; |
| 163 | } |
| 164 | |
| 165 | /* The longest message defined in RFC 2637 is 220 bytes, but the protocol |
| 166 | * itself allows up to 65536 bytes. Therefore we always read a complete |
| 167 | * message but only keep the first 220 bytes before passing up. */ |
| 168 | length = incoming.expect - incoming.length; |
| 169 | if (incoming.length >= MAX_PACKET_LENGTH) { |
| 170 | uint8_t buffer[length]; |
| 171 | length = recv(the_socket, buffer, length, 0); |
| 172 | } else { |
| 173 | if (incoming.expect > MAX_PACKET_LENGTH) { |
| 174 | length = MAX_PACKET_LENGTH - incoming.length; |
| 175 | } |
| 176 | length = recv(the_socket, &incoming.buffer[incoming.length], length, 0); |
| 177 | } |
| 178 | if (length == -1) { |
| 179 | if (errno == EINTR) { |
| 180 | return 0; |
| 181 | } |
| 182 | log_print(FATAL, "Recv() %s", strerror(errno)); |
| 183 | exit(NETWORK_ERROR); |
| 184 | } |
| 185 | if (length == 0) { |
| 186 | log_print(DEBUG, "Connection closed"); |
| 187 | log_print(INFO, "Remote server hung up"); |
| 188 | return -REMOTE_REQUESTED; |
| 189 | } |
| 190 | incoming.length += length; |
| 191 | |
| 192 | /* If incoming.header is valid, check cookie and update incoming.expect. */ |
| 193 | if (incoming.length == HEADER_SIZE && incoming.expect == HEADER_SIZE) { |
| 194 | if (incoming.header.cookie != MAGIC_COOKIE) { |
| 195 | log_print(DEBUG, "Loss of synchronization"); |
| 196 | log_print(ERROR, "Protocol error"); |
| 197 | return -PROTOCOL_ERROR; |
| 198 | } |
| 199 | incoming.expect = ntohs(incoming.header.length); |
| 200 | if (incoming.expect < HEADER_SIZE) { |
| 201 | log_print(DEBUG, "Invalid message length"); |
| 202 | log_print(ERROR, "Protocol error"); |
| 203 | return -PROTOCOL_ERROR; |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | /* Now we have a complete message. Reset incoming.expect. */ |
| 208 | if (incoming.length == incoming.expect) { |
| 209 | incoming.expect = 0; |
| 210 | |
| 211 | /* Return 1 if it is a control message. */ |
| 212 | if (incoming.header.type == CONTROL_MESSAGE) { |
| 213 | return 1; |
| 214 | } |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 215 | log_print(DEBUG, "Ignored non-control message (type = %u)", |
| 216 | (unsigned)ntohs(incoming.header.type)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 217 | } |
| 218 | return 0; |
| 219 | } |
| 220 | |
Chia-chi Yeh | 7b66d20 | 2011-06-28 16:39:23 -0700 | [diff] [blame] | 221 | static int pptp_connect(char **arguments) |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 222 | { |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 223 | remote_name = arguments[0]; |
| 224 | |
Chia-chi Yeh | 7b66d20 | 2011-06-28 16:39:23 -0700 | [diff] [blame] | 225 | create_socket(AF_UNSPEC, SOCK_STREAM, arguments[0], arguments[1]); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 226 | |
| 227 | log_print(DEBUG, "Sending SCCRQ"); |
| 228 | state = SCCRQ; |
| 229 | set_message(SCCRQ); |
| 230 | outgoing.sccrq.protocol_version = PROTOCOL_VERSION; |
| 231 | outgoing.sccrq.framing = htonl(3); |
| 232 | outgoing.sccrq.bearer = htonl(3); |
| 233 | outgoing.sccrq.channels = htons(1); |
| 234 | strcpy(outgoing.sccrq.host, "anonymous"); |
| 235 | send_packet(); |
| 236 | return 0; |
| 237 | } |
| 238 | |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 239 | /** |
Alistair Strachan | d799900 | 2019-05-23 17:19:07 -0700 | [diff] [blame] | 240 | * Check if upstream kernel implementation of PPTP should be used. |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 241 | * |
Alistair Strachan | d799900 | 2019-05-23 17:19:07 -0700 | [diff] [blame] | 242 | * @return true If upstream PPTP should be used, which is the case if |
| 243 | * the obsolete OPNS feature is not available. |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 244 | */ |
| 245 | static bool check_pptp(void) |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 246 | { |
Alistair Strachan | d799900 | 2019-05-23 17:19:07 -0700 | [diff] [blame] | 247 | int fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OPNS); |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 248 | |
| 249 | if (fd < 0) { |
Alistair Strachan | d799900 | 2019-05-23 17:19:07 -0700 | [diff] [blame] | 250 | return true; |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 251 | } else { |
| 252 | close(fd); |
Alistair Strachan | d799900 | 2019-05-23 17:19:07 -0700 | [diff] [blame] | 253 | return false; |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 254 | } |
| 255 | } |
| 256 | |
| 257 | /** |
| 258 | * Create OPNS session. |
| 259 | * |
| 260 | * @deprecated It will be removed soon in favor of upstream PPTP. |
| 261 | * |
| 262 | * @return PPPoX socket file descriptor |
| 263 | */ |
| 264 | static int create_pppox_opns(void) |
| 265 | { |
| 266 | int pppox; |
| 267 | |
| 268 | log_print(WARNING, "Using deprecated OPNS protocol. " |
| 269 | "Its support will be removed soon. " |
| 270 | "Please enable PPTP support in your kernel"); |
| 271 | |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 272 | log_print(INFO, "Creating PPPoX socket"); |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 273 | pppox = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OPNS); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 274 | |
| 275 | if (pppox == -1) { |
| 276 | log_print(FATAL, "Socket() %s", strerror(errno)); |
Chia-chi Yeh | 0f72585 | 2011-07-18 13:57:17 -0700 | [diff] [blame] | 277 | exit(SYSTEM_ERROR); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 278 | } else { |
| 279 | struct sockaddr_pppopns address = { |
| 280 | .sa_family = AF_PPPOX, |
Chia-chi Yeh | 0f72585 | 2011-07-18 13:57:17 -0700 | [diff] [blame] | 281 | .sa_protocol = PX_PROTO_OPNS, |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 282 | .tcp_socket = the_socket, |
| 283 | .local = local, |
| 284 | .remote = remote, |
| 285 | }; |
Chia-chi Yeh | ea299e6 | 2011-07-13 19:36:46 -0700 | [diff] [blame] | 286 | if (connect(pppox, (struct sockaddr *)&address, sizeof(address))) { |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 287 | log_print(FATAL, "Connect() %s", strerror(errno)); |
Chia-chi Yeh | 0f72585 | 2011-07-18 13:57:17 -0700 | [diff] [blame] | 288 | exit(SYSTEM_ERROR); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 289 | } |
| 290 | } |
| 291 | return pppox; |
| 292 | } |
| 293 | |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 294 | /** |
| 295 | * Get IP address by host name. |
| 296 | * |
| 297 | * @param name Host name to get IP address for |
| 298 | * |
| 299 | * @return IP address for given host name |
| 300 | */ |
| 301 | static struct in_addr get_addr_by_name(const char *name) |
| 302 | { |
| 303 | struct addrinfo hints; |
| 304 | struct addrinfo *res, *rp; |
| 305 | struct in_addr addr; |
| 306 | int err; |
| 307 | |
| 308 | memset(&hints, 0, sizeof(struct addrinfo)); |
| 309 | hints.ai_family = AF_INET; /* allow only IPv4 */ |
| 310 | hints.ai_socktype = SOCK_DGRAM; /* UDP */ |
| 311 | hints.ai_protocol = 0; /* any protocol */ |
| 312 | |
| 313 | err = getaddrinfo(name, NULL, &hints, &res); |
| 314 | if (err) { |
| 315 | log_print(FATAL, "%s: getaddrinfo: %s", __func__, gai_strerror(err)); |
| 316 | exit(SYSTEM_ERROR); |
| 317 | } |
| 318 | |
| 319 | for (rp = res; rp != NULL; rp = rp->ai_next) { |
| 320 | /* For now we only support IPv4 */ |
| 321 | if (rp->ai_family == AF_INET) { |
| 322 | addr = ((struct sockaddr_in *)rp->ai_addr)->sin_addr; |
| 323 | break; |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | if (rp == NULL) { |
| 328 | log_print(FATAL, "%s: No IPv4 addresses found", __func__); |
| 329 | freeaddrinfo(res); |
| 330 | exit(SYSTEM_ERROR); |
| 331 | } |
| 332 | |
| 333 | freeaddrinfo(res); |
| 334 | |
| 335 | return addr; |
| 336 | } |
| 337 | |
| 338 | /** |
| 339 | * Get local IP address. |
| 340 | * |
| 341 | * Make a socket connection with remote server and then call getsockname() on |
| 342 | * the connected socket. This will return the local IP address. |
| 343 | * |
| 344 | * @param remote_addr Server IP address |
| 345 | * |
| 346 | * @return Local IP address |
| 347 | */ |
| 348 | static struct in_addr get_local_addr(struct in_addr remote_addr) |
| 349 | { |
| 350 | int sock; |
| 351 | struct sockaddr_in addr; |
| 352 | socklen_t addr_len; |
| 353 | |
| 354 | addr_len = sizeof(struct sockaddr_in); |
| 355 | addr.sin_addr = remote_addr; |
| 356 | addr.sin_family = AF_INET; |
| 357 | addr.sin_port = htons(0); |
| 358 | |
| 359 | sock = socket(AF_INET, SOCK_DGRAM, 0); |
| 360 | if (sock < 0) { |
| 361 | log_print(FATAL, "%s: Socket() %s", __func__, strerror(errno)); |
| 362 | exit(SYSTEM_ERROR); |
| 363 | } |
| 364 | |
| 365 | if (connect(sock, (struct sockaddr*)&addr, sizeof(addr))) { |
| 366 | close(sock); |
| 367 | log_print(FATAL, "%s: Connect() %s", __func__, strerror(errno)); |
| 368 | exit(SYSTEM_ERROR); |
| 369 | } |
| 370 | |
| 371 | getsockname(sock, (struct sockaddr*)&addr, &addr_len); |
| 372 | close(sock); |
| 373 | |
| 374 | return addr.sin_addr; |
| 375 | } |
| 376 | |
| 377 | /** |
| 378 | * Create PPTP session. |
| 379 | * |
| 380 | * @return PPTP socket file descriptor |
| 381 | */ |
| 382 | static int create_pppox_pptp(void) |
| 383 | { |
| 384 | int pptp_fd; |
| 385 | struct sockaddr_pppox src, dst; |
| 386 | struct in_addr remote_addr; /* server IP address */ |
| 387 | struct in_addr local_addr; /* client IP address */ |
| 388 | |
| 389 | remote_addr = get_addr_by_name(remote_name); |
| 390 | local_addr = get_local_addr(remote_addr); |
| 391 | |
| 392 | src.sa_family = AF_PPPOX; |
| 393 | src.sa_protocol = PX_PROTO_PPTP; |
| 394 | src.sa_addr.pptp.call_id = ntohs(local); |
| 395 | src.sa_addr.pptp.sin_addr = local_addr; |
| 396 | |
| 397 | dst.sa_family = AF_PPPOX; |
| 398 | dst.sa_protocol = PX_PROTO_PPTP; |
| 399 | dst.sa_addr.pptp.call_id = ntohs(remote); |
| 400 | dst.sa_addr.pptp.sin_addr = remote_addr; |
| 401 | |
| 402 | pptp_fd = socket(AF_PPPOX, SOCK_STREAM, PX_PROTO_PPTP); |
| 403 | if (pptp_fd < 0) { |
| 404 | log_print(FATAL, "Failed to create PPTP socket (%s)", strerror(errno)); |
| 405 | exit(SYSTEM_ERROR); |
| 406 | } |
| 407 | |
| 408 | if (bind(pptp_fd, (struct sockaddr*)&src, sizeof(src))) { |
| 409 | log_print(FATAL, "Failed to bind PPTP socket (%s)", strerror(errno)); |
| 410 | close(pptp_fd); |
| 411 | exit(SYSTEM_ERROR); |
| 412 | } |
| 413 | |
| 414 | if (connect(pptp_fd, (struct sockaddr*)&dst, sizeof(dst))) { |
| 415 | log_print(FATAL, "Failed to connect PPTP socket (%s)", strerror(errno)); |
| 416 | close(pptp_fd); |
| 417 | exit(SYSTEM_ERROR); |
| 418 | } |
| 419 | |
| 420 | return pptp_fd; |
| 421 | } |
| 422 | |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 423 | static int pptp_process() |
| 424 | { |
| 425 | int result = recv_packet(); |
| 426 | if (result <= 0) { |
| 427 | return result; |
| 428 | } |
| 429 | |
| 430 | if (incoming.length < MIN_MESSAGE_SIZE) { |
| 431 | log_print(DEBUG, "Control message too short"); |
| 432 | return 0; |
| 433 | } |
| 434 | incoming.message = ntohs(incoming.message); |
| 435 | if (incoming.message > MESSAGE_MAX || !messages[incoming.message]) { |
| 436 | log_print(DEBUG, "Received UNKNOWN %d", incoming.message); |
| 437 | return 0; |
| 438 | } |
| 439 | if (incoming.length < lengths[incoming.message]) { |
| 440 | log_print(DEBUG, "Received %s with invalid length (length = %d)", |
Chia-chi Yeh | ea299e6 | 2011-07-13 19:36:46 -0700 | [diff] [blame] | 441 | messages[incoming.message], incoming.length); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 442 | return 0; |
| 443 | } |
| 444 | |
| 445 | switch(incoming.message) { |
| 446 | case SCCRP: |
| 447 | if (state == SCCRQ) { |
Chia-chi Yeh | ea299e6 | 2011-07-13 19:36:46 -0700 | [diff] [blame] | 448 | if (incoming.sccrp.protocol_version == PROTOCOL_VERSION && |
| 449 | ESTABLISHED(incoming.sccrp.result)) { |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 450 | while (!local) { |
| 451 | local = random(); |
| 452 | } |
| 453 | log_print(DEBUG, "Received SCCRP -> Sending OCRQ " |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 454 | "(local = %u)", (unsigned)ntohs(local)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 455 | log_print(INFO, "Tunnel established"); |
| 456 | state = OCRQ; |
| 457 | set_message(OCRQ); |
| 458 | outgoing.ocrq.call = local; |
| 459 | outgoing.ocrq.serial = random(); |
| 460 | outgoing.ocrq.minimum_speed = htonl(1000); |
| 461 | outgoing.ocrq.maximum_speed = htonl(100000000); |
| 462 | outgoing.ocrq.bearer = htonl(3); |
| 463 | outgoing.ocrq.framing = htonl(3); |
| 464 | outgoing.ocrq.window_size = htons(8192); |
| 465 | send_packet(); |
| 466 | return 0; |
| 467 | } |
| 468 | log_print(DEBUG, "Received SCCRP (result = %d)", |
Chia-chi Yeh | ea299e6 | 2011-07-13 19:36:46 -0700 | [diff] [blame] | 469 | incoming.sccrq.result); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 470 | log_print(INFO, "Remote server hung up"); |
| 471 | return -REMOTE_REQUESTED; |
| 472 | } |
| 473 | break; |
| 474 | |
| 475 | case OCRP: |
| 476 | if (state == OCRQ && incoming.ocrp.peer == local) { |
| 477 | if (ESTABLISHED(incoming.ocrp.result)) { |
| 478 | remote = incoming.ocrp.call; |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 479 | log_print(DEBUG, "Received OCRQ (remote = %u)", |
| 480 | (unsigned)ntohs(remote)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 481 | log_print(INFO, "Session established"); |
| 482 | state = OCRP; |
Sam Protsenko | 0368bbd | 2018-06-08 01:11:16 +0300 | [diff] [blame] | 483 | |
| 484 | if (check_pptp()) |
| 485 | start_pppd_pptp(create_pppox_pptp()); |
| 486 | else |
| 487 | start_pppd(create_pppox_opns()); |
| 488 | |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 489 | return 0; |
| 490 | } |
| 491 | log_print(DEBUG, "Received OCRP (result = %d)", |
Chia-chi Yeh | ea299e6 | 2011-07-13 19:36:46 -0700 | [diff] [blame] | 492 | incoming.ocrp.result); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 493 | log_print(INFO, "Remote server hung up"); |
| 494 | return -REMOTE_REQUESTED; |
| 495 | } |
| 496 | break; |
| 497 | |
| 498 | case STOPCCRQ: |
| 499 | log_print(DEBUG, "Received STOPCCRQ"); |
| 500 | log_print(INFO, "Remote server hung up"); |
| 501 | state = STOPCCRQ; |
| 502 | return -REMOTE_REQUESTED; |
| 503 | |
| 504 | case CCRQ: |
| 505 | /* According to RFC 2637 page 45, we should never receive CCRQ for |
| 506 | * outgoing calls. However, some implementation only acts as PNS and |
| 507 | * always uses CCRQ to clear a call, so here we still handle it. */ |
| 508 | if (state == OCRP && incoming.ccrq.call == remote) { |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 509 | log_print(DEBUG, "Received CCRQ (remote = %u)", |
| 510 | (unsigned)ntohs(remote)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 511 | log_print(INFO, "Remote server hung up"); |
| 512 | return -REMOTE_REQUESTED; |
| 513 | } |
| 514 | break; |
| 515 | |
| 516 | case CDN: |
| 517 | if (state == OCRP && incoming.cdn.call == remote) { |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 518 | log_print(DEBUG, "Received CDN (remote = %u)", |
| 519 | (unsigned)ntohs(remote)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 520 | log_print(INFO, "Remote server hung up"); |
| 521 | return -REMOTE_REQUESTED; |
| 522 | } |
| 523 | break; |
| 524 | |
| 525 | case ECHORQ: |
| 526 | log_print(DEBUG, "Received ECHORQ -> Sending ECHORP"); |
| 527 | set_message(ECHORP); |
| 528 | outgoing.echorp.identifier = incoming.echorq.identifier; |
| 529 | outgoing.echorp.result = RESULT_OK; |
| 530 | send_packet(); |
| 531 | return 0; |
| 532 | |
| 533 | case WEN: |
| 534 | case SLI: |
| 535 | log_print(DEBUG, "Recevied %s", messages[incoming.message]); |
| 536 | return 0; |
| 537 | |
| 538 | case ICRQ: |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 539 | log_print(DEBUG, "Received ICRQ (remote = %u, call = %u) -> " |
| 540 | "Sending ICRP with error", (unsigned)ntohs(remote), |
| 541 | (unsigned)ntohs(incoming.icrq.call)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 542 | set_message(ICRP); |
| 543 | outgoing.icrp.peer = incoming.icrq.call; |
| 544 | outgoing.icrp.result = RESULT_ERROR; |
| 545 | send_packet(); |
| 546 | return 0; |
| 547 | |
| 548 | case OCRQ: |
Sam Protsenko | 537773c | 2018-06-25 21:20:39 +0300 | [diff] [blame] | 549 | log_print(DEBUG, "Received OCRQ (remote = %u, call = %u) -> " |
| 550 | "Sending OCRP with error", (unsigned)ntohs(remote), |
| 551 | (unsigned)ntohs(incoming.ocrq.call)); |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 552 | set_message(OCRP); |
| 553 | outgoing.ocrp.peer = incoming.ocrq.call; |
| 554 | outgoing.ocrp.result = RESULT_ERROR; |
| 555 | send_packet(); |
| 556 | return 0; |
| 557 | } |
| 558 | |
| 559 | /* We reach here if we got an unexpected message. Just log it. */ |
| 560 | log_print(DEBUG, "Received UNEXPECTED %s", messages[incoming.message]); |
| 561 | return 0; |
| 562 | } |
| 563 | |
| 564 | static int pptp_timeout() |
| 565 | { |
| 566 | return 0; |
| 567 | } |
| 568 | |
| 569 | static void pptp_shutdown() |
| 570 | { |
| 571 | /* Normally we should send STOPCCRQ and wait for STOPCCRP, but this might |
| 572 | * block for a long time. Here we simply take the shortcut: do nothing. */ |
| 573 | } |
| 574 | |
| 575 | struct protocol pptp = { |
| 576 | .name = "pptp", |
Chia-chi Yeh | 7b66d20 | 2011-06-28 16:39:23 -0700 | [diff] [blame] | 577 | .arguments = 2, |
Chia-chi Yeh | 063bb92 | 2009-06-15 14:43:38 +0800 | [diff] [blame] | 578 | .usage = "<server> <port>", |
| 579 | .connect = pptp_connect, |
| 580 | .process = pptp_process, |
| 581 | .timeout = pptp_timeout, |
| 582 | .shutdown = pptp_shutdown, |
| 583 | }; |