diff options
Diffstat (limited to 'release/src/router/busybox/networking/tftp.c')
| -rw-r--r-- | release/src/router/busybox/networking/tftp.c | 1119 |
1 files changed, 636 insertions, 483 deletions
diff --git a/release/src/router/busybox/networking/tftp.c b/release/src/router/busybox/networking/tftp.c index a1a79a09..9c78b6e1 100644 --- a/release/src/router/busybox/networking/tftp.c +++ b/release/src/router/busybox/networking/tftp.c @@ -1,58 +1,37 @@ -/* ------------------------------------------------------------------------- */ -/* tftp.c */ -/* */ -/* A simple tftp client for busybox. */ -/* Tries to follow RFC1350. */ -/* Only "octet" mode supported. */ -/* Optional blocksize negotiation (RFC2347 + RFC2348) */ -/* */ -/* Copyright (C) 2001 Magnus Damm <damm@opensource.se> */ -/* */ -/* Parts of the code based on: */ -/* */ -/* atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca> */ -/* and Remi Lefebvre <remi@debian.org> */ -/* */ -/* utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de> */ -/* */ -/* This program is free software; you can redistribute it and/or modify */ -/* it under the terms of the GNU General Public License as published by */ -/* the Free Software Foundation; either version 2 of the License, or */ -/* (at your option) any later version. */ -/* */ -/* This program is distributed in the hope that it will be useful, */ -/* but WITHOUT ANY WARRANTY; without even the implied warranty of */ -/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU */ -/* General Public License for more details. */ -/* */ -/* You should have received a copy of the GNU General Public License */ -/* along with this program; if not, write to the Free Software */ -/* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -/* */ -/* ------------------------------------------------------------------------- */ - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/types.h> -#include <sys/socket.h> -#include <sys/time.h> -#include <sys/stat.h> -#include <netdb.h> -#include <netinet/in.h> -#include <arpa/inet.h> -#include <unistd.h> -#include <fcntl.h> - -#include "busybox.h" - -//#define CONFIG_FEATURE_TFTP_DEBUG - -#define TFTP_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ -#define TFTP_TIMEOUT 5 /* seconds */ +/* vi: set sw=4 ts=4: */ +/* ------------------------------------------------------------------------- + * tftp.c + * + * A simple tftp client/server for busybox. + * Tries to follow RFC1350. + * Only "octet" mode supported. + * Optional blocksize negotiation (RFC2347 + RFC2348) + * + * Copyright (C) 2001 Magnus Damm <damm@opensource.se> + * + * Parts of the code based on: + * + * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca> + * and Remi Lefebvre <remi@debian.org> + * + * utftp: Copyright (C) 1999 Uwe Ohse <uwe@ohse.de> + * + * tftpd added by Denys Vlasenko & Vladimir Dronnikov + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + * ------------------------------------------------------------------------- */ + +#include "libbb.h" + +#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT + +#define TFTP_BLKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ +#define TFTP_BLKSIZE_DEFAULT_STR "512" +#define TFTP_TIMEOUT_MS 50 +#define TFTP_MAXTIMEOUT_MS 2000 +#define TFTP_NUM_RETRIES 12 /* number of backed-off retries */ /* opcodes we support */ - #define TFTP_RRQ 1 #define TFTP_WRQ 2 #define TFTP_DATA 3 @@ -60,528 +39,702 @@ #define TFTP_ERROR 5 #define TFTP_OACK 6 -static const char *tftp_bb_error_msg[] = { - "Undefined error", - "File not found", - "Access violation", - "Disk full or allocation error", - "Illegal TFTP operation", - "Unknown transfer ID", - "File already exists", - "No such user" +/* error codes sent over network (we use only 0, 1, 3 and 8) */ +/* generic (error message is included in the packet) */ +#define ERR_UNSPEC 0 +#define ERR_NOFILE 1 +#define ERR_ACCESS 2 +/* disk full or allocation exceeded */ +#define ERR_WRITE 3 +#define ERR_OP 4 +#define ERR_BAD_ID 5 +#define ERR_EXIST 6 +#define ERR_BAD_USER 7 +#define ERR_BAD_OPT 8 + +/* masks coming from getopt32 */ +enum { + TFTP_OPT_GET = (1 << 0), + TFTP_OPT_PUT = (1 << 1), + /* pseudo option: if set, it's tftpd */ + TFTPD_OPT = (1 << 7) * ENABLE_TFTPD, + TFTPD_OPT_r = (1 << 8) * ENABLE_TFTPD, + TFTPD_OPT_c = (1 << 9) * ENABLE_TFTPD, + TFTPD_OPT_u = (1 << 10) * ENABLE_TFTPD, +}; + +#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT +#define USE_GETPUT(...) +#define CMD_GET(cmd) 1 +#define CMD_PUT(cmd) 0 +#elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT +#define USE_GETPUT(...) +#define CMD_GET(cmd) 0 +#define CMD_PUT(cmd) 1 +#else +#define USE_GETPUT(...) __VA_ARGS__ +#define CMD_GET(cmd) ((cmd) & TFTP_OPT_GET) +#define CMD_PUT(cmd) ((cmd) & TFTP_OPT_PUT) +#endif +/* NB: in the code below + * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive + */ + + +struct globals { + /* u16 TFTP_ERROR; u16 reason; both network-endian, then error text: */ + uint8_t error_pkt[4 + 32]; + char *user_opt; + /* used in tftpd_main(), a bit big for stack: */ + char block_buf[TFTP_BLKSIZE_DEFAULT]; }; +#define G (*(struct globals*)&bb_common_bufsiz1) +#define block_buf (G.block_buf ) +#define user_opt (G.user_opt ) +#define error_pkt (G.error_pkt ) +#define INIT_G() do { } while (0) + +#define error_pkt_reason (error_pkt[3]) +#define error_pkt_str (error_pkt + 4) -const int tftp_cmd_get = 1; -const int tftp_cmd_put = 2; -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE +#if ENABLE_FEATURE_TFTP_BLOCKSIZE -static int tftp_blocksize_check(int blocksize, int bufsize) +static int tftp_blksize_check(const char *blksize_str, int maxsize) { - /* Check if the blocksize is valid: + /* Check if the blksize is valid: * RFC2348 says between 8 and 65464, * but our implementation makes it impossible - * to use blocksizes smaller than 22 octets. - */ - - if ((bufsize && (blocksize > bufsize)) || - (blocksize < 8) || (blocksize > 65464)) { - bb_error_msg("bad blocksize"); - return 0; + * to use blksizes smaller than 22 octets. */ + unsigned blksize = bb_strtou(blksize_str, NULL, 10); + if (errno + || (blksize < 24) || (blksize > maxsize) + ) { + bb_error_msg("bad blocksize '%s'", blksize_str); + return -1; } - - return blocksize; +#if ENABLE_TFTP_DEBUG + bb_error_msg("using blksize %u", blksize); +#endif + return blksize; } -static char *tftp_option_get(char *buf, int len, char *option) +static char *tftp_get_option(const char *option, char *buf, int len) { - int opt_val = 0; + int opt_val = 0; int opt_found = 0; int k; - - while (len > 0) { - /* Make sure the options are terminated correctly */ + /* buf points to: + * "opt_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */ - for (k = 0; k < len; k++) { - if (buf[k] == '\0') { - break; + while (len > 0) { + /* Make sure options are terminated correctly */ + for (k = 0; k < len; k++) { + if (buf[k] == '\0') { + goto nul_found; } } - - if (k >= len) { - break; - } - - if (opt_val == 0) { + return NULL; + nul_found: + if (opt_val == 0) { /* it's "name" part */ if (strcasecmp(buf, option) == 0) { - opt_found = 1; - } - } - else { - if (opt_found) { - return buf; + opt_found = 1; } + } else if (opt_found) { + return buf; } - + k++; - buf += k; len -= k; - opt_val ^= 1; } - + return NULL; } #endif -static inline int tftp(const int cmd, const struct hostent *host, - const char *remotefile, int localfd, const int port, int tftp_bufsize) +static int tftp_protocol( + len_and_sockaddr *our_lsa, + len_and_sockaddr *peer_lsa, + const char *local_file + USE_TFTP(, const char *remote_file) + USE_FEATURE_TFTP_BLOCKSIZE(USE_TFTPD(, void *tsize)) + USE_FEATURE_TFTP_BLOCKSIZE(, int blksize)) { - const int cmd_get = cmd & tftp_cmd_get; - const int cmd_put = cmd & tftp_cmd_put; - const int bb_tftp_num_retries = 5; - - struct sockaddr_in sa; - struct sockaddr_in from; - struct timeval tv; - socklen_t fromlen; - fd_set rfds; - char *cp; - unsigned short tmp; - int socketfd; - int len; - int opcode = 0; - int finished = 0; - int timeout = bb_tftp_num_retries; - int block_nr = 1; - -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - int want_option_ack = 0; +#if !ENABLE_TFTP +#define remote_file NULL +#endif +#if !(ENABLE_FEATURE_TFTP_BLOCKSIZE && ENABLE_TFTPD) +#define tsize NULL +#endif +#if !ENABLE_FEATURE_TFTP_BLOCKSIZE + enum { blksize = TFTP_BLKSIZE_DEFAULT }; #endif + struct pollfd pfd[1]; +#define socket_fd (pfd[0].fd) + int len; + int send_len; + USE_FEATURE_TFTP_BLOCKSIZE(smallint want_option_ack = 0;) + smallint finished = 0; + uint16_t opcode; + uint16_t block_nr; + uint16_t recv_blk; + int open_mode, local_fd; + int retries, waittime_ms; + int io_bufsize = blksize + 4; + char *cp; /* Can't use RESERVE_CONFIG_BUFFER here since the allocation * size varies meaning BUFFERS_GO_ON_STACK would fail */ - char *buf=xmalloc(tftp_bufsize + 4); - - tftp_bufsize += 4; + /* We must keep the transmit and receive buffers seperate */ + /* In case we rcv a garbage pkt and we need to rexmit the last pkt */ + char *xbuf = xmalloc(io_bufsize); + char *rbuf = xmalloc(io_bufsize); + + socket_fd = xsocket(peer_lsa->u.sa.sa_family, SOCK_DGRAM, 0); + setsockopt_reuseaddr(socket_fd); + + block_nr = 1; + cp = xbuf + 2; + + if (!ENABLE_TFTP || our_lsa) { + /* tftpd */ + + /* Create a socket which is: + * 1. bound to IP:port peer sent 1st datagram to, + * 2. connected to peer's IP:port + * This way we will answer from the IP:port peer + * expects, will not get any other packets on + * the socket, and also plain read/write will work. */ + xbind(socket_fd, &our_lsa->u.sa, our_lsa->len); + xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); + + /* Is there an error already? Send pkt and bail out */ + if (error_pkt_reason || error_pkt_str[0]) + goto send_err_pkt; + + if (CMD_GET(option_mask32)) { + /* it's upload - we must ACK 1st packet (with filename) + * as if it's "block 0" */ + block_nr = 0; + } - if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { - bb_perror_msg("socket"); - return EXIT_FAILURE; + if (user_opt) { + struct passwd *pw = xgetpwnam(user_opt); + change_identity(pw); /* initgroups, setgid, setuid */ + } } - len = sizeof(sa); - - memset(&sa, 0, len); - bind(socketfd, (struct sockaddr *)&sa, len); - - sa.sin_family = host->h_addrtype; - sa.sin_port = htons(port); - memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr, - sizeof(sa.sin_addr)); - - /* build opcode */ - - if (cmd_get) { - opcode = TFTP_RRQ; + /* Open local file (must be after changing user) */ + if (CMD_PUT(option_mask32)) { + open_mode = O_RDONLY; + } else { + open_mode = O_WRONLY | O_TRUNC | O_CREAT; +#if ENABLE_TFTPD + if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) { + /* tftpd without -c */ + open_mode = O_WRONLY | O_TRUNC; + } +#endif + } + if (!(option_mask32 & TFTPD_OPT)) { + local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO; + if (NOT_LONE_DASH(local_file)) + local_fd = xopen(local_file, open_mode); + } else { + local_fd = open(local_file, open_mode); + if (local_fd < 0) { + error_pkt_reason = ERR_NOFILE; + strcpy((char*)error_pkt_str, "can't open file"); + goto send_err_pkt; + } } - if (cmd_put) { + if (!ENABLE_TFTP || our_lsa) { +/* gcc 4.3.1 would NOT optimize it out as it should! */ +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (blksize != TFTP_BLKSIZE_DEFAULT || tsize) { + /* Create and send OACK packet. */ + /* For the download case, block_nr is still 1 - + * we expect 1st ACK from peer to be for (block_nr-1), + * that is, for "block 0" which is our OACK pkt */ + opcode = TFTP_OACK; + goto add_blksize_opt; + } +#endif + } else { +/* Removing it, or using if() statement instead of #if may lead to + * "warning: null argument where non-null required": */ +#if ENABLE_TFTP + /* tftp */ + + /* We can't (and don't really need to) bind the socket: + * we don't know from which local IP datagrams will be sent, + * but kernel will pick the same IP every time (unless routing + * table is changed), thus peer will see dgrams consistently + * coming from the same IP. + * We would like to connect the socket, but since peer's + * UDP code can be less perfect than ours, _peer's_ IP:port + * in replies may differ from IP:port we used to send + * our first packet. We can connect() only when we get + * first reply. */ + + /* build opcode */ opcode = TFTP_WRQ; + if (CMD_GET(option_mask32)) { + opcode = TFTP_RRQ; + } + /* add filename and mode */ + /* fill in packet if the filename fits into xbuf */ + len = strlen(remote_file) + 1; + if (2 + len + sizeof("octet") >= io_bufsize) { + bb_error_msg("remote filename is too long"); + goto ret; + } + strcpy(cp, remote_file); + cp += len; + /* add "mode" part of the package */ + strcpy(cp, "octet"); + cp += sizeof("octet"); + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (blksize == TFTP_BLKSIZE_DEFAULT) + goto send_pkt; + + /* Non-standard blocksize: add option to pkt */ + if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN")) { + bb_error_msg("remote filename is too long"); + goto ret; + } + want_option_ack = 1; +#endif +#endif /* ENABLE_TFTP */ + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + add_blksize_opt: +#if ENABLE_TFTPD + if (tsize) { + struct stat st; + /* add "tsize", <nul>, size, <nul> */ + strcpy(cp, "tsize"); + cp += sizeof("tsize"); + fstat(local_fd, &st); + cp += snprintf(cp, 10, "%u", (int) st.st_size) + 1; + } +#endif + if (blksize != TFTP_BLKSIZE_DEFAULT) { + /* add "blksize", <nul>, blksize, <nul> */ + strcpy(cp, "blksize"); + cp += sizeof("blksize"); + cp += snprintf(cp, 6, "%d", blksize) + 1; + } +#endif + /* First packet is built, so skip packet generation */ + goto send_pkt; } + /* Using mostly goto's - continue/break will be less clear + * in where we actually jump to */ while (1) { - - cp = buf; - - /* first create the opcode part */ - - *((unsigned short *) cp) = htons(opcode); - + /* Build ACK or DATA */ + cp = xbuf + 2; + *((uint16_t*)cp) = htons(block_nr); cp += 2; - - /* add filename and mode */ - - if ((cmd_get && (opcode == TFTP_RRQ)) || - (cmd_put && (opcode == TFTP_WRQ))) { - int too_long = 0; - - /* see if the filename fits into buf */ - /* and fill in packet */ - - len = strlen(remotefile) + 1; - - if ((cp + len) >= &buf[tftp_bufsize - 1]) { - too_long = 1; - } - else { - safe_strncpy(cp, remotefile, len); - cp += len; + block_nr++; + opcode = TFTP_ACK; + if (CMD_PUT(option_mask32)) { + opcode = TFTP_DATA; + len = full_read(local_fd, cp, blksize); + if (len < 0) { + goto send_read_err_pkt; } - - if (too_long || ((&buf[tftp_bufsize - 1] - cp) < 6)) { - bb_error_msg("too long remote-filename"); - break; - } - - /* add "mode" part of the package */ - - memcpy(cp, "octet", 6); - cp += 6; - -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - - len = tftp_bufsize - 4; /* data block size */ - - if (len != TFTP_BLOCKSIZE_DEFAULT) { - - if ((&buf[tftp_bufsize - 1] - cp) < 15) { - bb_error_msg("too long remote-filename"); - break; - } - - /* add "blksize" + number of blocks */ - - memcpy(cp, "blksize", 8); - cp += 8; - - cp += snprintf(cp, 6, "%d", len) + 1; - - want_option_ack = 1; - } -#endif - } - - /* add ack and data */ - - if ((cmd_get && (opcode == TFTP_ACK)) || - (cmd_put && (opcode == TFTP_DATA))) { - - *((unsigned short *) cp) = htons(block_nr); - - cp += 2; - - block_nr++; - - if (cmd_put && (opcode == TFTP_DATA)) { - len = read(localfd, cp, tftp_bufsize - 4); - - if (len < 0) { - bb_perror_msg("read"); - break; - } - - if (len != (tftp_bufsize - 4)) { - finished++; - } - - cp += len; + if (len != blksize) { + finished = 1; } + cp += len; } - - - /* send packet */ - - - timeout = bb_tftp_num_retries; /* re-initialize */ - do { - - len = cp - buf; - -#ifdef CONFIG_FEATURE_TFTP_DEBUG - printf("sending %u bytes\n", len); - for (cp = buf; cp < &buf[len]; cp++) - printf("%02x ", *cp); - printf("\n"); + send_pkt: + /* Send packet */ + *((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */ + send_len = cp - xbuf; + /* NB: send_len value is preserved in code below + * for potential resend */ + + retries = TFTP_NUM_RETRIES; /* re-initialize */ + waittime_ms = TFTP_TIMEOUT_MS; + + send_again: +#if ENABLE_TFTP_DEBUG + fprintf(stderr, "sending %u bytes\n", send_len); + for (cp = xbuf; cp < &xbuf[send_len]; cp++) + fprintf(stderr, "%02x ", (unsigned char) *cp); + fprintf(stderr, "\n"); #endif - if (sendto(socketfd, buf, len, 0, - (struct sockaddr *) &sa, sizeof(sa)) < 0) { - bb_perror_msg("send"); - len = -1; - break; + xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); + /* Was it final ACK? then exit */ + if (finished && (opcode == TFTP_ACK)) + goto ret; + + recv_again: + /* Receive packet */ + /*pfd[0].fd = socket_fd;*/ + pfd[0].events = POLLIN; + switch (safe_poll(pfd, 1, waittime_ms)) { + default: + /*bb_perror_msg("poll"); - done in safe_poll */ + goto ret; + case 0: + retries--; + if (retries == 0) { + bb_error_msg("timeout"); + goto ret; /* no err packet sent */ } - - if (finished && (opcode == TFTP_ACK)) { - break; + /* exponential backoff with limit */ + waittime_ms += waittime_ms/2; + if (waittime_ms > TFTP_MAXTIMEOUT_MS) { + waittime_ms = TFTP_MAXTIMEOUT_MS; } - /* receive packet */ - - memset(&from, 0, sizeof(from)); - fromlen = sizeof(from); - - tv.tv_sec = TFTP_TIMEOUT; - tv.tv_usec = 0; - - FD_ZERO(&rfds); - FD_SET(socketfd, &rfds); - - switch (select(FD_SETSIZE, &rfds, NULL, NULL, &tv)) { - case 1: - len = recvfrom(socketfd, buf, tftp_bufsize, 0, - (struct sockaddr *) &from, &fromlen); - - if (len < 0) { - bb_perror_msg("recvfrom"); - break; - } - - timeout = 0; - - if (sa.sin_port == htons(port)) { - sa.sin_port = from.sin_port; - } - if (sa.sin_port == from.sin_port) { - break; - } - - /* fall-through for bad packets! */ - /* discard the packet - treat as timeout */ - timeout = bb_tftp_num_retries; - - case 0: - bb_error_msg("timeout"); - - timeout--; - if (timeout == 0) { - len = -1; - bb_error_msg("last timeout"); - } - break; - - default: - bb_perror_msg("select"); - len = -1; + goto send_again; /* resend last sent pkt */ + case 1: + if (!our_lsa) { + /* tftp (not tftpd!) receiving 1st packet */ + our_lsa = ((void*)(ptrdiff_t)-1); /* not NULL */ + len = recvfrom(socket_fd, rbuf, io_bufsize, 0, + &peer_lsa->u.sa, &peer_lsa->len); + /* Our first dgram went to port 69 + * but reply may come from different one. + * Remember and use this new port (and IP) */ + if (len >= 0) + xconnect(socket_fd, &peer_lsa->u.sa, peer_lsa->len); + } else { + /* tftpd, or not the very first packet: + * socket is connect()ed, can just read from it. */ + /* Don't full_read()! + * This is not TCP, one read == one pkt! */ + len = safe_read(socket_fd, rbuf, io_bufsize); + } + if (len < 0) { + goto send_read_err_pkt; + } + if (len < 4) { /* too small? */ + goto recv_again; } - - } while (timeout && (len >= 0)); - - if ((finished) || (len < 0)) { - break; } - /* process received packet */ - - - opcode = ntohs(*((unsigned short *) buf)); - tmp = ntohs(*((unsigned short *) &buf[2])); - -#ifdef CONFIG_FEATURE_TFTP_DEBUG - printf("received %d bytes: %04x %04x\n", len, opcode, tmp); + /* Process recv'ed packet */ + opcode = ntohs( ((uint16_t*)rbuf)[0] ); + recv_blk = ntohs( ((uint16_t*)rbuf)[1] ); +#if ENABLE_TFTP_DEBUG + fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk); #endif - if (opcode == TFTP_ERROR) { - char *msg = NULL; - - if (buf[4] != '\0') { - msg = &buf[4]; - buf[tftp_bufsize - 1] = '\0'; - } else if (tmp < (sizeof(tftp_bb_error_msg) - / sizeof(char *))) { - - msg = (char *) tftp_bb_error_msg[tmp]; - } - - if (msg) { - bb_error_msg("server says: %s", msg); + static const char errcode_str[] ALIGN1 = + "\0" + "file not found\0" + "access violation\0" + "disk full\0" + "bad operation\0" + "unknown transfer id\0" + "file already exists\0" + "no such user\0" + "bad option"; + + const char *msg = ""; + + if (len > 4 && rbuf[4] != '\0') { + msg = &rbuf[4]; + rbuf[io_bufsize - 1] = '\0'; /* paranoia */ + } else if (recv_blk <= 8) { + msg = nth_string(errcode_str, recv_blk); } - - break; + bb_error_msg("server error: (%u) %s", recv_blk, msg); + goto ret; } -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE +#if ENABLE_FEATURE_TFTP_BLOCKSIZE if (want_option_ack) { - - want_option_ack = 0; - - if (opcode == TFTP_OACK) { - - /* server seems to support options */ - - char *res; - - res = tftp_option_get(&buf[2], len-2, - "blksize"); - - if (res) { - int blksize = atoi(res); - - if (tftp_blocksize_check(blksize, - tftp_bufsize - 4)) { - - if (cmd_put) { - opcode = TFTP_DATA; - } - else { - opcode = TFTP_ACK; - } -#ifdef CONFIG_FEATURE_TFTP_DEBUG - printf("using blksize %u\n", blksize); -#endif - tftp_bufsize = blksize + 4; - block_nr = 0; - continue; - } - } - /* FIXME: - * we should send ERROR 8 */ - bb_error_msg("bad server option"); - break; - } - - bb_error_msg("warning: blksize not supported by server" - " - reverting to 512"); - - tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4; + want_option_ack = 0; + if (opcode == TFTP_OACK) { + /* server seems to support options */ + char *res; + + res = tftp_get_option("blksize", &rbuf[2], len - 2); + if (res) { + blksize = tftp_blksize_check(res, blksize); + if (blksize < 0) { + error_pkt_reason = ERR_BAD_OPT; + goto send_err_pkt; + } + io_bufsize = blksize + 4; + /* Send ACK for OACK ("block" no: 0) */ + block_nr = 0; + continue; + } + /* rfc2347: + * "An option not acknowledged by the server + * must be ignored by the client and server + * as if it were never requested." */ + } + bb_error_msg("server only supports blocksize of 512"); + blksize = TFTP_BLKSIZE_DEFAULT; + io_bufsize = TFTP_BLKSIZE_DEFAULT + 4; } #endif - - if (cmd_get && (opcode == TFTP_DATA)) { - - if (tmp == block_nr) { - - len = write(localfd, &buf[4], len - 4); - - if (len < 0) { - bb_perror_msg("write"); - break; + /* block_nr is already advanced to next block# we expect + * to get / block# we are about to send next time */ + + if (CMD_GET(option_mask32) && (opcode == TFTP_DATA)) { + if (recv_blk == block_nr) { + int sz = full_write(local_fd, &rbuf[4], len - 4); + if (sz != len - 4) { + strcpy((char*)error_pkt_str, bb_msg_write_error); + error_pkt_reason = ERR_WRITE; + goto send_err_pkt; } - - if (len != (tftp_bufsize - 4)) { - finished++; + if (sz != blksize) { + finished = 1; } - - opcode = TFTP_ACK; + continue; /* send ACK */ + } + if (recv_blk == (block_nr - 1)) { + /* Server lost our TFTP_ACK. Resend it */ + block_nr = recv_blk; continue; } } - if (cmd_put && (opcode == TFTP_ACK)) { - - if (tmp == (block_nr - 1)) { - if (finished) { - break; - } - - opcode = TFTP_DATA; - continue; + if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) { + /* did peer ACK our last DATA pkt? */ + if (recv_blk == (uint16_t) (block_nr - 1)) { + if (finished) + goto ret; + continue; /* send next block */ } } + /* Awww... recv'd packet is not recognized! */ + goto recv_again; + /* why recv_again? - rfc1123 says: + * "The sender (i.e., the side originating the DATA packets) + * must never resend the current DATA packet on receipt + * of a duplicate ACK". + * DATA pkts are resent ONLY on timeout. + * Thus "goto send_again" will ba a bad mistake above. + * See: + * http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome + */ + } /* end of "while (1)" */ + ret: + if (ENABLE_FEATURE_CLEAN_UP) { + close(local_fd); + close(socket_fd); + free(xbuf); + free(rbuf); } - -#ifdef CONFIG_FEATURE_CLEAN_UP - close(socketfd); - - free(buf); -#endif - - return finished ? EXIT_SUCCESS : EXIT_FAILURE; + return finished == 0; /* returns 1 on failure */ + + send_read_err_pkt: + strcpy((char*)error_pkt_str, bb_msg_read_error); + send_err_pkt: + if (error_pkt_str[0]) + bb_error_msg((char*)error_pkt_str); + error_pkt[1] = TFTP_ERROR; + xsendto(socket_fd, error_pkt, 4 + 1 + strlen((char*)error_pkt_str), + &peer_lsa->u.sa, peer_lsa->len); + return EXIT_FAILURE; +#undef remote_file +#undef tsize } -int tftp_main(int argc, char **argv) +#if ENABLE_TFTP + +int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int tftp_main(int argc UNUSED_PARAM, char **argv) { - struct hostent *host = NULL; - char *localfile = NULL; - char *remotefile = NULL; - int port = 69; - int cmd = 0; - int fd = -1; - int flags = 0; - int opt; + len_and_sockaddr *peer_lsa; + const char *local_file = NULL; + const char *remote_file = NULL; +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + const char *blksize_str = TFTP_BLKSIZE_DEFAULT_STR; + int blksize; +#endif int result; - int blocksize = TFTP_BLOCKSIZE_DEFAULT; + int port; + USE_GETPUT(int opt;) + + INIT_G(); + + /* -p or -g is mandatory, and they are mutually exclusive */ + opt_complementary = "" USE_FEATURE_TFTP_GET("g:") USE_FEATURE_TFTP_PUT("p:") + USE_GETPUT("g--p:p--g:"); + + USE_GETPUT(opt =) getopt32(argv, + USE_FEATURE_TFTP_GET("g") USE_FEATURE_TFTP_PUT("p") + "l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"), + &local_file, &remote_file + USE_FEATURE_TFTP_BLOCKSIZE(, &blksize_str)); + argv += optind; + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + /* Check if the blksize is valid: + * RFC2348 says between 8 and 65464 */ + blksize = tftp_blksize_check(blksize_str, 65564); + if (blksize < 0) { + //bb_error_msg("bad block size"); + return EXIT_FAILURE; + } +#endif - /* figure out what to pass to getopt */ + if (remote_file) { + if (!local_file) { + const char *slash = strrchr(remote_file, '/'); + local_file = slash ? slash + 1 : remote_file; + } + } else { + remote_file = local_file; + } -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE -#define BS "b:" -#else -#define BS -#endif + /* Error if filename or host is not known */ + if (!remote_file || !argv[0]) + bb_show_usage(); -#ifdef CONFIG_FEATURE_TFTP_GET -#define GET "g" -#else -#define GET -#endif + port = bb_lookup_port(argv[1], "udp", 69); + peer_lsa = xhost2sockaddr(argv[0], port); -#ifdef CONFIG_FEATURE_TFTP_PUT -#define PUT "p" -#else -#define PUT +#if ENABLE_TFTP_DEBUG + fprintf(stderr, "using server '%s', remote_file '%s', local_file '%s'\n", + xmalloc_sockaddr2dotted(&peer_lsa->u.sa), + remote_file, local_file); #endif - while ((opt = getopt(argc, argv, BS GET PUT "l:r:")) != -1) { - switch (opt) { -#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE - case 'b': - blocksize = atoi(optarg); - if (!tftp_blocksize_check(blocksize, 0)) { - return EXIT_FAILURE; - } - break; -#endif -#ifdef CONFIG_FEATURE_TFTP_GET - case 'g': - cmd = tftp_cmd_get; - flags = O_WRONLY | O_CREAT; - break; -#endif -#ifdef CONFIG_FEATURE_TFTP_PUT - case 'p': - cmd = tftp_cmd_put; - flags = O_RDONLY; - break; -#endif - case 'l': - localfile = bb_xstrdup(optarg); - break; - case 'r': - remotefile = bb_xstrdup(optarg); - break; - } + result = tftp_protocol( + NULL /*our_lsa*/, peer_lsa, + local_file, remote_file + USE_FEATURE_TFTP_BLOCKSIZE(USE_TFTPD(, NULL /*tsize*/)) + USE_FEATURE_TFTP_BLOCKSIZE(, blksize) + ); + + if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) { + unlink(local_file); } + return result; +} + +#endif /* ENABLE_TFTP */ - if ((cmd == 0) || (optind == argc)) { +#if ENABLE_TFTPD +int tftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int tftpd_main(int argc UNUSED_PARAM, char **argv) +{ + len_and_sockaddr *our_lsa; + len_and_sockaddr *peer_lsa; + char *local_file, *mode; + const char *error_msg; + int opt, result, opcode; + USE_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;) + USE_FEATURE_TFTP_BLOCKSIZE(char *tsize = NULL;) + + INIT_G(); + + our_lsa = get_sock_lsa(STDIN_FILENO); + if (!our_lsa) { + /* This is confusing: + *bb_error_msg_and_die("stdin is not a socket"); + * Better: */ bb_show_usage(); + /* Help text says that tftpd must be used as inetd service, + * which is by far the most usual cause of get_sock_lsa + * failure */ } - if(localfile && strcmp(localfile, "-") == 0) { - fd = fileno((cmd==tftp_cmd_get)? stdout : stdin); + peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len); + peer_lsa->len = our_lsa->len; + + /* Shifting to not collide with TFTP_OPTs */ + opt = option_mask32 = TFTPD_OPT | (getopt32(argv, "rcu:", &user_opt) << 8); + argv += optind; + if (argv[0]) + xchdir(argv[0]); + + result = recv_from_to(STDIN_FILENO, block_buf, sizeof(block_buf), + 0 /* flags */, + &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len); + + error_msg = "malformed packet"; + opcode = ntohs(*(uint16_t*)block_buf); + if (result < 4 || result >= sizeof(block_buf) + || block_buf[result-1] != '\0' + || (USE_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */ + USE_GETPUT(&&) + USE_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */ + ) + ) { + goto err; } - if(localfile == NULL) - localfile = remotefile; - if(remotefile == NULL) - remotefile = localfile; - if (fd==-1) { - fd = open(localfile, flags, 0644); + local_file = block_buf + 2; + if (local_file[0] == '.' || strstr(local_file, "/.")) { + error_msg = "dot in file name"; + goto err; } - if (fd < 0) { - bb_perror_msg_and_die("local file"); + mode = local_file + strlen(local_file) + 1; + if (mode >= block_buf + result || strcmp(mode, "octet") != 0) { + goto err; } - - host = xgethostbyname(argv[optind]); - - if (optind + 2 == argc) { - port = atoi(argv[optind + 1]); +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + { + char *res; + char *opt_str = mode + sizeof("octet"); + int opt_len = block_buf + result - opt_str; + if (opt_len > 0) { + res = tftp_get_option("blksize", opt_str, opt_len); + if (res) { + blksize = tftp_blksize_check(res, 65564); + if (blksize < 0) { + error_pkt_reason = ERR_BAD_OPT; + /* will just send error pkt */ + goto do_proto; + } + } + /* did client ask us about file size? */ + tsize = tftp_get_option("tsize", opt_str, opt_len); + } } - -#ifdef CONFIG_FEATURE_TFTP_DEBUG - printf("using server \"%s\", remotefile \"%s\", " - "localfile \"%s\".\n", - inet_ntoa(*((struct in_addr *) host->h_addr)), - remotefile, localfile); #endif - result = tftp(cmd, host, remotefile, fd, port, blocksize); - -#ifdef CONFIG_FEATURE_CLEAN_UP - if (!(fd == fileno(stdout) || fd == fileno(stdin))) { - close(fd); + if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) { + if (opt & TFTPD_OPT_r) { + /* This would mean "disk full" - not true */ + /*error_pkt_reason = ERR_WRITE;*/ + error_msg = bb_msg_write_error; + goto err; + } + USE_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */ + } else { + USE_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */ } -#endif - return(result); + + /* NB: if error_pkt_str or error_pkt_reason is set up, + * tftp_protocol() just sends one error pkt and returns */ + + do_proto: + close(STDIN_FILENO); /* close old, possibly wildcard socket */ + /* tftp_protocol() will create new one, bound to particular local IP */ + result = tftp_protocol( + our_lsa, peer_lsa, + local_file USE_TFTP(, NULL /*remote_file*/) + USE_FEATURE_TFTP_BLOCKSIZE(, tsize) + USE_FEATURE_TFTP_BLOCKSIZE(, blksize) + ); + + return result; + err: + strcpy((char*)error_pkt_str, error_msg); + goto do_proto; } + +#endif /* ENABLE_TFTPD */ + +#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */ |