| /** |
| * |
| * @file tftp_server.c |
| * |
| * @author Logan Gunthorpe <logang@deltatee.com> |
| * Dirk Ziegelmeier <dziegel@gmx.de> |
| * |
| * @brief Trivial File Transfer Protocol (RFC 1350) |
| * |
| * Copyright (c) Deltatee Enterprises Ltd. 2013 |
| * All rights reserved. |
| * |
| */ |
| |
| /* |
| * Redistribution and use in source and binary forms, with or without |
| * modification,are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED |
| * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| * Author: Logan Gunthorpe <logang@deltatee.com> |
| * Dirk Ziegelmeier <dziegel@gmx.de> |
| * |
| */ |
| |
| /** |
| * @defgroup tftp TFTP server |
| * @ingroup apps |
| * |
| * This is simple TFTP server for the lwIP raw API. |
| */ |
| |
| #include "lwip/apps/tftp_server.h" |
| |
| #if LWIP_UDP |
| |
| #include "lwip/udp.h" |
| #include "lwip/timeouts.h" |
| #include "lwip/debug.h" |
| |
| #define TFTP_MAX_PAYLOAD_SIZE 512 |
| #define TFTP_HEADER_LENGTH 4 |
| |
| #define TFTP_RRQ 1 |
| #define TFTP_WRQ 2 |
| #define TFTP_DATA 3 |
| #define TFTP_ACK 4 |
| #define TFTP_ERROR 5 |
| |
| enum tftp_error { |
| TFTP_ERROR_FILE_NOT_FOUND = 1, |
| TFTP_ERROR_ACCESS_VIOLATION = 2, |
| TFTP_ERROR_DISK_FULL = 3, |
| TFTP_ERROR_ILLEGAL_OPERATION = 4, |
| TFTP_ERROR_UNKNOWN_TRFR_ID = 5, |
| TFTP_ERROR_FILE_EXISTS = 6, |
| TFTP_ERROR_NO_SUCH_USER = 7 |
| }; |
| |
| #include <string.h> |
| |
| struct tftp_state { |
| const struct tftp_context *ctx; |
| void *handle; |
| struct pbuf *last_data; |
| struct udp_pcb *upcb; |
| ip_addr_t addr; |
| u16_t port; |
| int timer; |
| int last_pkt; |
| u16_t blknum; |
| u8_t retries; |
| u8_t mode_write; |
| }; |
| |
| static struct tftp_state tftp_state; |
| |
| static void tftp_tmr(void *arg); |
| |
| static void |
| close_handle(void) |
| { |
| tftp_state.port = 0; |
| ip_addr_set_any(0, &tftp_state.addr); |
| |
| if (tftp_state.last_data != NULL) { |
| pbuf_free(tftp_state.last_data); |
| tftp_state.last_data = NULL; |
| } |
| |
| sys_untimeout(tftp_tmr, NULL); |
| |
| if (tftp_state.handle) { |
| tftp_state.ctx->close(tftp_state.handle); |
| tftp_state.handle = NULL; |
| LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: closing\n")); |
| } |
| } |
| |
| static void |
| send_error(const ip_addr_t *addr, u16_t port, enum tftp_error code, const char *str) |
| { |
| int str_length = strlen(str); |
| struct pbuf *p; |
| u16_t *payload; |
| |
| p = pbuf_alloc(PBUF_TRANSPORT, (u16_t)(TFTP_HEADER_LENGTH + str_length + 1), PBUF_RAM); |
| if (p == NULL) { |
| return; |
| } |
| |
| payload = (u16_t *) p->payload; |
| payload[0] = PP_HTONS(TFTP_ERROR); |
| payload[1] = lwip_htons(code); |
| MEMCPY(&payload[2], str, str_length + 1); |
| |
| udp_sendto(tftp_state.upcb, p, addr, port); |
| pbuf_free(p); |
| } |
| |
| static void |
| send_ack(u16_t blknum) |
| { |
| struct pbuf *p; |
| u16_t *payload; |
| |
| p = pbuf_alloc(PBUF_TRANSPORT, TFTP_HEADER_LENGTH, PBUF_RAM); |
| if (p == NULL) { |
| return; |
| } |
| payload = (u16_t *) p->payload; |
| |
| payload[0] = PP_HTONS(TFTP_ACK); |
| payload[1] = lwip_htons(blknum); |
| udp_sendto(tftp_state.upcb, p, &tftp_state.addr, tftp_state.port); |
| pbuf_free(p); |
| } |
| |
| static void |
| resend_data(void) |
| { |
| struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, tftp_state.last_data->len, PBUF_RAM); |
| if (p == NULL) { |
| return; |
| } |
| |
| if (pbuf_copy(p, tftp_state.last_data) != ERR_OK) { |
| pbuf_free(p); |
| return; |
| } |
| |
| udp_sendto(tftp_state.upcb, p, &tftp_state.addr, tftp_state.port); |
| pbuf_free(p); |
| } |
| |
| static void |
| send_data(void) |
| { |
| u16_t *payload; |
| int ret; |
| |
| if (tftp_state.last_data != NULL) { |
| pbuf_free(tftp_state.last_data); |
| } |
| |
| tftp_state.last_data = pbuf_alloc(PBUF_TRANSPORT, TFTP_HEADER_LENGTH + TFTP_MAX_PAYLOAD_SIZE, PBUF_RAM); |
| if (tftp_state.last_data == NULL) { |
| return; |
| } |
| |
| payload = (u16_t *) tftp_state.last_data->payload; |
| payload[0] = PP_HTONS(TFTP_DATA); |
| payload[1] = lwip_htons(tftp_state.blknum); |
| |
| ret = tftp_state.ctx->read(tftp_state.handle, &payload[2], TFTP_MAX_PAYLOAD_SIZE); |
| if (ret < 0) { |
| send_error(&tftp_state.addr, tftp_state.port, TFTP_ERROR_ACCESS_VIOLATION, "Error occured while reading the file."); |
| close_handle(); |
| return; |
| } |
| |
| pbuf_realloc(tftp_state.last_data, (u16_t)(TFTP_HEADER_LENGTH + ret)); |
| resend_data(); |
| } |
| |
| static void |
| recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) |
| { |
| u16_t *sbuf = (u16_t *) p->payload; |
| int opcode; |
| |
| LWIP_UNUSED_ARG(arg); |
| LWIP_UNUSED_ARG(upcb); |
| |
| if (((tftp_state.port != 0) && (port != tftp_state.port)) || |
| (!ip_addr_isany_val(tftp_state.addr) && !ip_addr_cmp(&tftp_state.addr, addr))) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Only one connection at a time is supported"); |
| pbuf_free(p); |
| return; |
| } |
| |
| opcode = sbuf[0]; |
| |
| tftp_state.last_pkt = tftp_state.timer; |
| tftp_state.retries = 0; |
| |
| switch (opcode) { |
| case PP_HTONS(TFTP_RRQ): /* fall through */ |
| case PP_HTONS(TFTP_WRQ): { |
| const char tftp_null = 0; |
| char filename[TFTP_MAX_FILENAME_LEN + 1]; |
| char mode[TFTP_MAX_MODE_LEN + 1]; |
| u16_t filename_end_offset; |
| u16_t mode_end_offset; |
| |
| if (tftp_state.handle != NULL) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Only one connection at a time is supported"); |
| break; |
| } |
| |
| sys_timeout(TFTP_TIMER_MSECS, tftp_tmr, NULL); |
| |
| /* find \0 in pbuf -> end of filename string */ |
| filename_end_offset = pbuf_memfind(p, &tftp_null, sizeof(tftp_null), 2); |
| if ((u16_t)(filename_end_offset - 1) > sizeof(filename)) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Filename too long/not NULL terminated"); |
| break; |
| } |
| pbuf_copy_partial(p, filename, filename_end_offset - 1, 2); |
| |
| /* find \0 in pbuf -> end of mode string */ |
| mode_end_offset = pbuf_memfind(p, &tftp_null, sizeof(tftp_null), filename_end_offset + 1); |
| if ((u16_t)(mode_end_offset - filename_end_offset) > sizeof(mode)) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Mode too long/not NULL terminated"); |
| break; |
| } |
| pbuf_copy_partial(p, mode, mode_end_offset - filename_end_offset, filename_end_offset + 1); |
| |
| tftp_state.handle = tftp_state.ctx->open(filename, mode, opcode == PP_HTONS(TFTP_WRQ)); |
| tftp_state.blknum = 1; |
| |
| if (!tftp_state.handle) { |
| send_error(addr, port, TFTP_ERROR_FILE_NOT_FOUND, "Unable to open requested file."); |
| break; |
| } |
| |
| LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: %s request from ", (opcode == PP_HTONS(TFTP_WRQ)) ? "write" : "read")); |
| ip_addr_debug_print(TFTP_DEBUG | LWIP_DBG_STATE, addr); |
| LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, (" for '%s' mode '%s'\n", filename, mode)); |
| |
| ip_addr_copy(tftp_state.addr, *addr); |
| tftp_state.port = port; |
| |
| if (opcode == PP_HTONS(TFTP_WRQ)) { |
| tftp_state.mode_write = 1; |
| send_ack(0); |
| } else { |
| tftp_state.mode_write = 0; |
| send_data(); |
| } |
| |
| break; |
| } |
| |
| case PP_HTONS(TFTP_DATA): { |
| int ret; |
| u16_t blknum; |
| |
| if (tftp_state.handle == NULL) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "No connection"); |
| break; |
| } |
| |
| if (tftp_state.mode_write != 1) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Not a write connection"); |
| break; |
| } |
| |
| blknum = lwip_ntohs(sbuf[1]); |
| if (blknum == tftp_state.blknum) { |
| pbuf_remove_header(p, TFTP_HEADER_LENGTH); |
| |
| ret = tftp_state.ctx->write(tftp_state.handle, p); |
| if (ret < 0) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "error writing file"); |
| close_handle(); |
| } else { |
| send_ack(blknum); |
| } |
| |
| if (p->tot_len < TFTP_MAX_PAYLOAD_SIZE) { |
| close_handle(); |
| } else { |
| tftp_state.blknum++; |
| } |
| } else if ((u16_t)(blknum + 1) == tftp_state.blknum) { |
| /* retransmit of previous block, ack again (casting to u16_t to care for overflow) */ |
| send_ack(blknum); |
| } else { |
| send_error(addr, port, TFTP_ERROR_UNKNOWN_TRFR_ID, "Wrong block number"); |
| } |
| break; |
| } |
| |
| case PP_HTONS(TFTP_ACK): { |
| u16_t blknum; |
| int lastpkt; |
| |
| if (tftp_state.handle == NULL) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "No connection"); |
| break; |
| } |
| |
| if (tftp_state.mode_write != 0) { |
| send_error(addr, port, TFTP_ERROR_ACCESS_VIOLATION, "Not a read connection"); |
| break; |
| } |
| |
| blknum = lwip_ntohs(sbuf[1]); |
| if (blknum != tftp_state.blknum) { |
| send_error(addr, port, TFTP_ERROR_UNKNOWN_TRFR_ID, "Wrong block number"); |
| break; |
| } |
| |
| lastpkt = 0; |
| |
| if (tftp_state.last_data != NULL) { |
| lastpkt = tftp_state.last_data->tot_len != (TFTP_MAX_PAYLOAD_SIZE + TFTP_HEADER_LENGTH); |
| } |
| |
| if (!lastpkt) { |
| tftp_state.blknum++; |
| send_data(); |
| } else { |
| close_handle(); |
| } |
| |
| break; |
| } |
| |
| default: |
| send_error(addr, port, TFTP_ERROR_ILLEGAL_OPERATION, "Unknown operation"); |
| break; |
| } |
| |
| pbuf_free(p); |
| } |
| |
| static void |
| tftp_tmr(void *arg) |
| { |
| LWIP_UNUSED_ARG(arg); |
| |
| tftp_state.timer++; |
| |
| if (tftp_state.handle == NULL) { |
| return; |
| } |
| |
| sys_timeout(TFTP_TIMER_MSECS, tftp_tmr, NULL); |
| |
| if ((tftp_state.timer - tftp_state.last_pkt) > (TFTP_TIMEOUT_MSECS / TFTP_TIMER_MSECS)) { |
| if ((tftp_state.last_data != NULL) && (tftp_state.retries < TFTP_MAX_RETRIES)) { |
| LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: timeout, retrying\n")); |
| resend_data(); |
| tftp_state.retries++; |
| } else { |
| LWIP_DEBUGF(TFTP_DEBUG | LWIP_DBG_STATE, ("tftp: timeout\n")); |
| close_handle(); |
| } |
| } |
| } |
| |
| /** @ingroup tftp |
| * Initialize TFTP server. |
| * @param ctx TFTP callback struct |
| */ |
| err_t |
| tftp_init(const struct tftp_context *ctx) |
| { |
| err_t ret; |
| |
| /* LWIP_ASSERT_CORE_LOCKED(); is checked by udp_new() */ |
| struct udp_pcb *pcb = udp_new_ip_type(IPADDR_TYPE_ANY); |
| if (pcb == NULL) { |
| return ERR_MEM; |
| } |
| |
| ret = udp_bind(pcb, IP_ANY_TYPE, TFTP_PORT); |
| if (ret != ERR_OK) { |
| udp_remove(pcb); |
| return ret; |
| } |
| |
| tftp_state.handle = NULL; |
| tftp_state.port = 0; |
| tftp_state.ctx = ctx; |
| tftp_state.timer = 0; |
| tftp_state.last_data = NULL; |
| tftp_state.upcb = pcb; |
| |
| udp_recv(pcb, recv, NULL); |
| |
| return ERR_OK; |
| } |
| |
| /** @ingroup tftp |
| * Deinitialize ("turn off") TFTP server. |
| */ |
| void tftp_cleanup(void) |
| { |
| LWIP_ASSERT("Cleanup called on non-initialized TFTP", tftp_state.upcb != NULL); |
| udp_remove(tftp_state.upcb); |
| close_handle(); |
| memset(&tftp_state, 0, sizeof(tftp_state)); |
| } |
| |
| #endif /* LWIP_UDP */ |