1 /** 2 * 3 * @file tftp.c 4 * 5 * @author Logan Gunthorpe <logang@deltatee.com> 6 * Dirk Ziegelmeier <dziegel@gmx.de> 7 * 8 * @brief Trivial File Transfer Protocol (RFC 1350) 9 * 10 * Copyright (c) Deltatee Enterprises Ltd. 2013 11 * All rights reserved. 12 * 13 */ 14 15 /* 16 * Redistribution and use in source and binary forms, with or without 17 * modification,are permitted provided that the following conditions are met: 18 * 19 * 1. Redistributions of source code must retain the above copyright notice, 20 * this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright notice, 22 * this list of conditions and the following disclaimer in the documentation 23 * and/or other materials provided with the distribution. 24 * 3. The name of the author may not be used to endorse or promote products 25 * derived from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 28 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 29 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 30 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 31 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 32 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 * 38 * Author: Logan Gunthorpe <logang@deltatee.com> 39 * Dirk Ziegelmeier <dziegel@gmx.de> 40 * 41 */ 42 43 /** 44 * @defgroup tftp TFTP client/server 45 * @ingroup apps 46 * 47 * This is simple TFTP client/server for the lwIP raw API. 48 * You need to increase MEMP_NUM_SYS_TIMEOUT by one if you use TFTP! 49 */ 50 51 #include "lwip/apps/tftp_client.h" 52 #include "lwip/apps/tftp_server.h" 53 54 #if LWIP_UDP 55 56 #include "lwip/udp.h" 57 #include "lwip/timeouts.h" 58 #include "lwip/debug.h" 59 60 #define TFTP_MAX_PAYLOAD_SIZE 512 61 #define TFTP_HEADER_LENGTH 4 62 63 #define TFTP_RRQ 1 64 #define TFTP_WRQ 2 65 #define TFTP_DATA 3 66 #define TFTP_ACK 4 67 #define TFTP_ERROR 5 68 69 enum tftp_error { 70 TFTP_ERROR_FILE_NOT_FOUND = 1, 71 TFTP_ERROR_ACCESS_VIOLATION = 2, 72 TFTP_ERROR_DISK_FULL = 3, 73 TFTP_ERROR_ILLEGAL_OPERATION = 4, 74 TFTP_ERROR_UNKNOWN_TRFR_ID = 5, 75 TFTP_ERROR_FILE_EXISTS = 6, 76 TFTP_ERROR_NO_SUCH_USER = 7 77 }; 78 79 #include <string.h> 80 81 struct tftp_state { 82 const struct tftp_context *ctx; 83 void *handle; 84 struct pbuf *last_data; 85 struct udp_pcb *upcb; 86 ip_addr_t addr; 87 u16_t port; 88 int timer; 89 int last_pkt; 90 u16_t blknum; 91 u8_t retries; 92 u8_t mode_write; 93 u8_t tftp_mode; 94 }; 95 96 static struct tftp_state tftp_state; 97 98 static void tftp_tmr(void *arg); 99 100 static void 101 close_handle(void) 102 { 103 tftp_state.port = 0; 104 ip_addr_set_any(0, &tftp_state.addr); 105 106 if (tftp_state.last_data != NULL) { 107 pbuf_free(tftp_state.last_data); 108 tftp_state.last_data = NULL; 109 } 110 111 sys_untimeout(tftp_tmr, NULL); 112 113 if (tftp_state.handle) { 114 tftp_state.ctx->close(tftp_state.handle); 115 tftp_state.handle = NULL; 116 LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: closing\n")); 117 } 118 } 119 120 static struct pbuf* 121 init_packet(u16_t opcode, u16_t extra, size_t size) 122 { 123 struct pbuf* p = pbuf_alloc(PBUF_TRANSPORT, (u16_t)(TFTP_HEADER_LENGTH + size), PBUF_RAM); 124 u16_t* payload; 125 126 if (p != NULL) { 127 payload = (u16_t*) p->payload; 128 payload[0] = PP_HTONS(opcode); 129 payload[1] = lwip_htons(extra); 130 } 131 132 return p; 133 } 134 135 static err_t 136 send_request(const ip_addr_t *addr, u16_t port, u16_t opcode, const char* fname, const char* mode) 137 { 138 size_t fname_length = strlen(fname)+1; 139 size_t mode_length = strlen(mode)+1; 140 struct pbuf* p = init_packet(opcode, 0, fname_length + mode_length - 2); 141 char* payload; 142 err_t ret; 143 144 if (p == NULL) { 145 return ERR_MEM; 146 } 147 148 payload = (char*) p->payload; 149 MEMCPY(payload+2, fname, fname_length); 150 MEMCPY(payload+2+fname_length, mode, mode_length); 151 152 ret = udp_sendto(tftp_state.upcb, p, addr, port); 153 pbuf_free(p); 154 return ret; 155 } 156 157 static err_t 158 send_error(const ip_addr_t *addr, u16_t port, enum tftp_error code, const char *str) 159 { 160 int str_length = strlen(str); 161 struct pbuf *p; 162 u16_t *payload; 163 err_t ret; 164 165 p = init_packet(TFTP_ERROR, code, str_length + 1); 166 if (p == NULL) { 167 return ERR_MEM; 168 } 169 170 payload = (u16_t *) p->payload; 171 MEMCPY(&payload[2], str, str_length + 1); 172 173 ret = udp_sendto(tftp_state.upcb, p, addr, port); 174 pbuf_free(p); 175 return ret; 176 } 177 178 static err_t 179 send_ack(const ip_addr_t *addr, u16_t port, u16_t blknum) 180 { 181 struct pbuf *p; 182 err_t ret; 183 184 p = init_packet(TFTP_ACK, blknum, 0); 185 if (p == NULL) { 186 return ERR_MEM; 187 } 188 189 ret = udp_sendto(tftp_state.upcb, p, addr, port); 190 pbuf_free(p); 191 return ret; 192 } 193 194 static err_t 195 resend_data(const ip_addr_t *addr, u16_t port) 196 { 197 err_t ret; 198 struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, tftp_state.last_data->len, PBUF_RAM); 199 if (p == NULL) { 200 return ERR_MEM; 201 } 202 203 ret = pbuf_copy(p, tftp_state.last_data); 204 if (ret != ERR_OK) { 205 pbuf_free(p); 206 return ret; 207 } 208 209 ret = udp_sendto(tftp_state.upcb, p, addr, port); 210 pbuf_free(p); 211 return ret; 212 } 213 214 static void 215 send_data(const ip_addr_t *addr, u16_t port) 216 { 217 u16_t *payload; 218 int ret; 219 220 if (tftp_state.last_data != NULL) { 221 pbuf_free(tftp_state.last_data); 222 } 223 224 tftp_state.last_data = init_packet(TFTP_DATA, tftp_state.blknum, TFTP_MAX_PAYLOAD_SIZE); 225 if (tftp_state.last_data == NULL) { 226 return; 227 } 228 229 payload = (u16_t *) tftp_state.last_data->payload; 230 231 ret = tftp_state.ctx->read(tftp_state.handle, &payload[2], TFTP_MAX_PAYLOAD_SIZE); 232 if (ret < 0) { 233 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Error occurred while reading the file."); 234 close_handle(); 235 return; 236 } 237 238 pbuf_realloc(tftp_state.last_data, (u16_t)(TFTP_HEADER_LENGTH + ret)); 239 resend_data(addr, port); 240 } 241 242 static void 243 tftp_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) 244 { 245 u16_t *sbuf = (u16_t *) p->payload; 246 int opcode; 247 248 LWIP_UNUSED_ARG(arg); 249 LWIP_UNUSED_ARG(upcb); 250 251 if (((tftp_state.port != 0) && (port != tftp_state.port)) || 252 (!ip_addr_isany_val(tftp_state.addr) && !ip_addr_eq(&tftp_state.addr, addr))) { 253 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Only one connection at a time is supported"); 254 pbuf_free(p); 255 return; 256 } 257 258 opcode = sbuf[0]; 259 260 tftp_state.last_pkt = tftp_state.timer; 261 tftp_state.retries = 0; 262 263 switch (opcode) { 264 case PP_HTONS(TFTP_RRQ): /* fall through */ 265 case PP_HTONS(TFTP_WRQ): { 266 const char tftp_null = 0; 267 char filename[TFTP_MAX_FILENAME_LEN + 1]; 268 char mode[TFTP_MAX_MODE_LEN + 1]; 269 u16_t filename_end_offset; 270 u16_t mode_end_offset; 271 272 if (tftp_state.handle != NULL) { 273 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Only one connection at a time is supported"); 274 break; 275 } 276 277 if ((tftp_state.tftp_mode & LWIP_TFTP_MODE_SERVER) == 0) { 278 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "TFTP server not enabled"); 279 break; 280 } 281 282 sys_timeout(TFTP_TIMER_MSECS, tftp_tmr, NULL); 283 284 /* find \0 in pbuf -> end of filename string */ 285 filename_end_offset = pbuf_memfind(p, &tftp_null, sizeof(tftp_null), 2); 286 if ((u16_t)(filename_end_offset - 1) > sizeof(filename)) { 287 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Filename too long/not NULL terminated"); 288 break; 289 } 290 pbuf_copy_partial(p, filename, filename_end_offset - 1, 2); 291 292 /* find \0 in pbuf -> end of mode string */ 293 mode_end_offset = pbuf_memfind(p, &tftp_null, sizeof(tftp_null), filename_end_offset + 1); 294 if ((u16_t)(mode_end_offset - filename_end_offset) > sizeof(mode)) { 295 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Mode too long/not NULL terminated"); 296 break; 297 } 298 pbuf_copy_partial(p, mode, mode_end_offset - filename_end_offset, filename_end_offset + 1); 299 300 tftp_state.handle = tftp_state.ctx->open(filename, mode, opcode == PP_HTONS(TFTP_WRQ)); 301 tftp_state.blknum = 1; 302 303 if (!tftp_state.handle) { 304 send_error(addr, port, TFTP_ERROR_FILE_NOT_FOUND, "Unable to open requested file."); 305 break; 306 } 307 308 LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: %s request from ", (opcode == PP_HTONS(TFTP_WRQ)) ? "write" : "read")); 309 ip_addr_debug_print(TFTP_DEBUG | LWIP_DBG_STATE, addr); 310 LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, (" for '%s' mode '%s'\n", filename, mode)); 311 312 ip_addr_copy(tftp_state.addr, *addr); 313 tftp_state.port = port; 314 315 if (opcode == PP_HTONS(TFTP_WRQ)) { 316 tftp_state.mode_write = 1; 317 send_ack(addr, port, 0); 318 } else { 319 tftp_state.mode_write = 0; 320 send_data(addr, port); 321 } 322 323 break; 324 } 325 326 case PP_HTONS(TFTP_DATA): { 327 int ret; 328 u16_t blknum; 329 330 if (tftp_state.handle == NULL) { 331 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "No connection"); 332 break; 333 } 334 335 if (tftp_state.mode_write != 1) { 336 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Not a write connection"); 337 break; 338 } 339 340 blknum = lwip_ntohs(sbuf[1]); 341 if (blknum == tftp_state.blknum) { 342 pbuf_remove_header(p, TFTP_HEADER_LENGTH); 343 344 ret = tftp_state.ctx->write(tftp_state.handle, p); 345 if (ret < 0) { 346 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "error writing file"); 347 close_handle(); 348 } else { 349 send_ack(addr, port, blknum); 350 } 351 352 if (p->tot_len < TFTP_MAX_PAYLOAD_SIZE) { 353 close_handle(); 354 } else { 355 tftp_state.blknum++; 356 } 357 } else if ((u16_t)(blknum + 1) == tftp_state.blknum) { 358 /* retransmit of previous block, ack again (casting to u16_t to care for overflow) */ 359 send_ack(addr, port, blknum); 360 } else { 361 send_error(addr, port, TFTP_ERROR_UNKNOWN_TRFR_ID, "Wrong block number"); 362 } 363 break; 364 } 365 366 case PP_HTONS(TFTP_ACK): { 367 u16_t blknum; 368 int lastpkt; 369 370 if (tftp_state.handle == NULL) { 371 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "No connection"); 372 break; 373 } 374 375 if (tftp_state.mode_write != 0) { 376 send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Not a read connection"); 377 break; 378 } 379 380 blknum = lwip_ntohs(sbuf[1]); 381 if (blknum != tftp_state.blknum) { 382 send_error(addr, port, TFTP_ERROR_UNKNOWN_TRFR_ID, "Wrong block number"); 383 break; 384 } 385 386 lastpkt = 0; 387 388 if (tftp_state.last_data != NULL) { 389 lastpkt = tftp_state.last_data->tot_len != (TFTP_MAX_PAYLOAD_SIZE + TFTP_HEADER_LENGTH); 390 } 391 392 if (!lastpkt) { 393 tftp_state.blknum++; 394 send_data(addr, port); 395 } else { 396 close_handle(); 397 } 398 399 break; 400 } 401 case PP_HTONS(TFTP_ERROR): 402 if (tftp_state.handle != NULL) { 403 pbuf_remove_header(p, TFTP_HEADER_LENGTH); 404 tftp_state.ctx->error(tftp_state.handle, sbuf[1], (const char*)p->payload, p->len); 405 close_handle(); 406 } 407 break; 408 default: 409 send_error(addr, port, TFTP_ERROR_ILLEGAL_OPERATION, "Unknown operation"); 410 break; 411 } 412 413 pbuf_free(p); 414 } 415 416 static void 417 tftp_tmr(void *arg) 418 { 419 LWIP_UNUSED_ARG(arg); 420 421 tftp_state.timer++; 422 423 if (tftp_state.handle == NULL) { 424 return; 425 } 426 427 sys_timeout(TFTP_TIMER_MSECS, tftp_tmr, NULL); 428 429 if ((tftp_state.timer - tftp_state.last_pkt) > (TFTP_TIMEOUT_MSECS / TFTP_TIMER_MSECS)) { 430 if ((tftp_state.last_data != NULL) && (tftp_state.retries < TFTP_MAX_RETRIES)) { 431 LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: timeout, retrying\n")); 432 resend_data(&tftp_state.addr, tftp_state.port); 433 tftp_state.retries++; 434 } else { 435 LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: timeout\n")); 436 close_handle(); 437 } 438 } 439 } 440 441 /** 442 * Initialize TFTP client/server. 443 * @param mode TFTP mode (client/server) 444 * @param ctx TFTP callback struct 445 */ 446 err_t 447 tftp_init_common(u8_t mode, const struct tftp_context *ctx) 448 { 449 err_t ret; 450 451 /* LWIP_ASSERT_CORE_LOCKED(); is checked by udp_new() */ 452 struct udp_pcb *pcb = udp_new_ip_type(IPADDR_TYPE_ANY); 453 if (pcb == NULL) { 454 return ERR_MEM; 455 } 456 457 ret = udp_bind(pcb, IP_ANY_TYPE, TFTP_PORT); 458 if (ret != ERR_OK) { 459 udp_remove(pcb); 460 return ret; 461 } 462 463 tftp_state.handle = NULL; 464 tftp_state.port = 0; 465 tftp_state.ctx = ctx; 466 tftp_state.timer = 0; 467 tftp_state.last_data = NULL; 468 tftp_state.upcb = pcb; 469 tftp_state.tftp_mode = mode; 470 471 udp_recv(pcb, tftp_recv, NULL); 472 473 return ERR_OK; 474 } 475 476 /** @ingroup tftp 477 * Initialize TFTP server. 478 * @param ctx TFTP callback struct 479 */ 480 err_t 481 tftp_init_server(const struct tftp_context *ctx) 482 { 483 return tftp_init_common(LWIP_TFTP_MODE_SERVER, ctx); 484 } 485 486 /** @ingroup tftp 487 * Initialize TFTP client. 488 * @param ctx TFTP callback struct 489 */ 490 err_t 491 tftp_init_client(const struct tftp_context *ctx) 492 { 493 return tftp_init_common(LWIP_TFTP_MODE_CLIENT, ctx); 494 } 495 496 /** @ingroup tftp 497 * Deinitialize ("turn off") TFTP client/server. 498 */ 499 void tftp_cleanup(void) 500 { 501 LWIP_ASSERT("Cleanup called on non-initialized TFTP", tftp_state.upcb != NULL); 502 udp_remove(tftp_state.upcb); 503 close_handle(); 504 memset(&tftp_state, 0, sizeof(tftp_state)); 505 } 506 507 static const char * 508 mode_to_string(enum tftp_transfer_mode mode) 509 { 510 if (mode == TFTP_MODE_OCTET) { 511 return "octet"; 512 } 513 if (mode == TFTP_MODE_NETASCII) { 514 return "netascii"; 515 } 516 if (mode == TFTP_MODE_BINARY) { 517 return "binary"; 518 } 519 return NULL; 520 } 521 522 err_t 523 tftp_get(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, enum tftp_transfer_mode mode) 524 { 525 LWIP_ERROR("TFTP client is not enabled (tftp_init)", (tftp_state.tftp_mode & LWIP_TFTP_MODE_CLIENT) != 0, return ERR_VAL); 526 LWIP_ERROR("tftp_get: invalid file name", fname != NULL, return ERR_VAL); 527 LWIP_ERROR("tftp_get: invalid mode", mode <= TFTP_MODE_BINARY, return ERR_VAL); 528 529 tftp_state.handle = handle; 530 tftp_state.blknum = 1; 531 tftp_state.mode_write = 1; /* We want to receive data */ 532 return send_request(addr, port, TFTP_RRQ, fname, mode_to_string(mode)); 533 } 534 535 err_t 536 tftp_put(void* handle, const ip_addr_t *addr, u16_t port, const char* fname, enum tftp_transfer_mode mode) 537 { 538 LWIP_ERROR("TFTP client is not enabled (tftp_init)", (tftp_state.tftp_mode & LWIP_TFTP_MODE_CLIENT) != 0, return ERR_VAL); 539 LWIP_ERROR("tftp_put: invalid file name", fname != NULL, return ERR_VAL); 540 LWIP_ERROR("tftp_put: invalid mode", mode <= TFTP_MODE_BINARY, return ERR_VAL); 541 542 tftp_state.handle = handle; 543 tftp_state.blknum = 1; 544 tftp_state.mode_write = 0; /* We want to send data */ 545 return send_request(addr, port, TFTP_WRQ, fname, mode_to_string(mode)); 546 } 547 548 #endif /* LWIP_UDP */ 549