X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Ftftp.c;h=a2683971a87e6c88f9f6ef5f179b0841347efb2f;hb=1641d614fa13b87b38688bb845159493c821e476;hp=309df36b301d1a7b88a82cd278b1e0897060d1d1;hpb=6b2c23d847a0942e6dcc5735a5a5512ab1432d28;p=oweals%2Fbusybox.git diff --git a/networking/tftp.c b/networking/tftp.c index 309df36b3..a2683971a 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -1,419 +1,466 @@ -/* ------------------------------------------------------------------------- */ -/* tftp.c */ -/* */ -/* A simple tftp client for busybox. */ -/* Tries to follow RFC1350. */ -/* Only "octet" mode and 512-byte data blocks are supported. */ -/* */ -/* Copyright (C) 2001 Magnus Damm */ -/* */ -/* Parts of the code based on: */ -/* */ -/* atftp: Copyright (C) 2000 Jean-Pierre Lefebvre */ -/* and Remi Lefebvre */ -/* */ -/* utftp: Copyright (C) 1999 Uwe Ohse */ -/* */ -/* 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 -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "busybox.h" - -//#define BB_FEATURE_TFTP_DEBUG - -/* we don't need #ifdefs with these constants and optimization... */ - -#ifdef BB_FEATURE_TFTP_GET -#define BB_TFTP_GET (1 << 0) +/* vi: set sw=4 ts=4: */ +/* ------------------------------------------------------------------------- + * 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 + * + * Parts of the code based on: + * + * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre + * and Remi Lefebvre + * + * utftp: Copyright (C) 1999 Uwe Ohse + * + * 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_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */ +#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 +#define TFTP_ACK 4 +#define TFTP_ERROR 5 +#define TFTP_OACK 6 + +#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 BB_TFTP_GET 0 +#define USE_GETPUT(...) __VA_ARGS__ +/* masks coming from getpot32 */ +#define CMD_GET(cmd) ((cmd) & 1) +#define CMD_PUT(cmd) ((cmd) & 2) #endif +/* NB: in the code below + * CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive + */ -#ifdef BB_FEATURE_TFTP_PUT -#define BB_TFTP_PUT (1 << 1) -#else -#define BB_TFTP_PUT 0 -#endif -#ifdef BB_FEATURE_TFTP_DEBUG -#define BB_TFTP_DEBUG 1 -#else -#define BB_TFTP_DEBUG 0 -#endif +#if ENABLE_FEATURE_TFTP_BLOCKSIZE -#define BB_TFTP_NO_RETRIES 5 -#define BB_TFTP_TIMEOUT 5 /* seconds */ - -#define RRQ 1 /* read request */ -#define WRQ 2 /* write request */ -#define DATA 3 /* data packet */ -#define ACK 4 /* acknowledgement */ -#define ERROR 5 /* error code */ - -#define BUFSIZE (512+4) - -static const char *tftp_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" -}; - -static inline int tftp(int cmd, struct hostent *host, - char *serverfile, int localfd, int port) +static int tftp_blocksize_check(int blocksize, int bufsize) { - struct sockaddr_in sa; - int socketfd; - struct timeval tv; - fd_set rfds; - struct sockaddr_in from; - socklen_t fromlen; - char *cp; - unsigned short tmp; - int len, opcode, finished; - int timeout, block_nr; - - RESERVE_BB_BUFFER(buf, BUFSIZE); - - opcode = finished = timeout = 0; - block_nr = 1; - - if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { - perror_msg("socket"); - return EXIT_FAILURE; + /* Check if the blocksize 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 > 65564) + ) { + bb_error_msg("bad blocksize"); + return 0; } - len = sizeof(sa); - - memset(&sa, 0, len); - bind(socketfd, &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 */ + return blocksize; +} - if (cmd & BB_TFTP_GET) { - opcode = RRQ; - } +static char *tftp_option_get(char *buf, int len, const char *option) +{ + int opt_val = 0; + int opt_found = 0; + int k; + + while (len > 0) { + /* Make sure the options are terminated correctly */ + for (k = 0; k < len; k++) { + if (buf[k] == '\0') { + goto nul_found; + } + } + return NULL; + nul_found: + if (opt_val == 0) { + if (strcasecmp(buf, option) == 0) { + opt_found = 1; + } + } else if (opt_found) { + return buf; + } - if (cmd & BB_TFTP_PUT) { - opcode = WRQ; + k++; + buf += k; + len -= k; + opt_val ^= 1; } - while (1) { + return NULL; +} +#endif - /* build packet of type "opcode" */ +static int tftp( USE_GETPUT(const int cmd,) + len_and_sockaddr *peer_lsa, + const char *remotefile, const int localfd, + unsigned port, int tftp_bufsize) +{ + struct pollfd pfd[1]; +#define socketfd (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 = 1; + uint16_t recv_blk; + int retries, waittime_ms; + char *cp; + unsigned org_port; + len_and_sockaddr *const from = alloca(offsetof(len_and_sockaddr, sa) + peer_lsa->len); - cp = buf; + /* Can't use RESERVE_CONFIG_BUFFER here since the allocation + * size varies meaning BUFFERS_GO_ON_STACK would fail */ + /* 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(tftp_bufsize += 4); + char *rbuf = xmalloc(tftp_bufsize); - *((unsigned short *) cp) = htons(opcode); + port = org_port = htons(port); - cp += 2; + socketfd = xsocket(peer_lsa->sa.sa_family, SOCK_DGRAM, 0); - /* add filename and mode */ + /* build opcode */ + opcode = TFTP_WRQ; + if (CMD_GET(cmd)) { + opcode = TFTP_RRQ; + } + cp = xbuf + 2; + /* add filename and mode */ + /* fill in packet if the filename fits into xbuf */ + len = strlen(remotefile) + 1; + if (2 + len + sizeof("octet") >= tftp_bufsize) { + bb_error_msg("remote filename is too long"); + goto ret; + } + strcpy(cp, remotefile); + cp += len; + /* add "mode" part of the package */ + strcpy(cp, "octet"); + cp += sizeof("octet"); + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + len = tftp_bufsize - 4; /* data block size */ + if (len != TFTP_BLOCKSIZE_DEFAULT) { + /* rfc2348 says that 65464 is a max allowed value */ + if ((&xbuf[tftp_bufsize - 1] - cp) < sizeof("blksize NNNNN")) { + bb_error_msg("remote filename is too long"); + goto ret; + } + /* add "blksize", , blocksize */ + strcpy(cp, "blksize"); + cp += sizeof("blksize"); + cp += snprintf(cp, 6, "%d", len) + 1; + want_option_ack = 1; + } +#endif + /* First packet is built, so skip packet generation */ + goto send_pkt; - if ((BB_TFTP_GET && (opcode == RRQ)) || - (BB_TFTP_PUT && (opcode == WRQ))) { + /* Using mostly goto's - continue/break will be less clear + * in where we actually jump to */ - while (cp != &buf[BUFSIZE - 1]) { - if ((*cp = *serverfile++) == '\0') - break; - cp++; + while (1) { + /* Build ACK or DATA */ + cp = xbuf + 2; + *((uint16_t*)cp) = htons(block_nr); + cp += 2; + block_nr++; + opcode = TFTP_ACK; + if (CMD_PUT(cmd)) { + opcode = TFTP_DATA; + len = full_read(localfd, cp, tftp_bufsize - 4); + if (len < 0) { + bb_perror_msg(bb_msg_read_error); + goto ret; } - - if ((*cp != '\0') || (&buf[BUFSIZE - 1] - cp) < 7) { - error_msg("too long server-filename"); - break; + if (len != (tftp_bufsize - 4)) { + finished = 1; } - - memcpy(cp + 1, "octet", 6); - cp += 7; + cp += len; } - - /* add ack and data */ - - if ((BB_TFTP_GET && (opcode == ACK)) || - (BB_TFTP_PUT && (opcode == DATA))) { - - *((unsigned short *) cp) = htons(block_nr); - - cp += 2; - - block_nr++; - - if (BB_TFTP_PUT && (opcode == DATA)) { - len = read(localfd, cp, BUFSIZE - 4); - - if (len < 0) { - perror_msg("read"); - break; - } - - if (len != (BUFSIZE - 4)) { - finished++; - } - - cp += len; - } else if (finished) { - break; + 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_DEBUG_TFTP + 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 + xsendto(socketfd, xbuf, send_len, &peer_lsa->sa, peer_lsa->len); + /* Was it final ACK? then exit */ + if (finished && (opcode == TFTP_ACK)) + goto ret; + + recv_again: + /* Receive packet */ + /*pfd[0].fd = socketfd;*/ + pfd[0].events = POLLIN; + switch (safe_poll(pfd, 1, waittime_ms)) { + unsigned from_port; + case 1: + from->len = peer_lsa->len; + memset(&from->sa, 0, peer_lsa->len); + len = recvfrom(socketfd, rbuf, tftp_bufsize, 0, + &from->sa, &from->len); + if (len < 0) { + bb_perror_msg("recvfrom"); + goto ret; } - } - - - /* send packet */ - - - do { - - len = cp - buf; - - if (BB_TFTP_DEBUG) { - printf("sending %u bytes\n", len); - - for (cp = buf; cp < &buf[len]; cp++) - printf("%02x ", *cp); - printf("\n"); + from_port = get_nport(&from->sa); + if (port == org_port) { + /* Our first query went to port 69 + * but reply will come from different one. + * Remember and use this new port */ + port = from_port; + set_nport(peer_lsa, from_port); } - - if (sendto(socketfd, buf, len, 0, - (struct sockaddr *) &sa, sizeof(sa)) < 0) { - perror_msg("send"); - len = -1; - break; + if (port != from_port) + goto recv_again; + goto process_pkt; + case 0: + retries--; + if (retries == 0) { + bb_error_msg("timeout"); + goto ret; } - - /* receive packet */ - - - memset(&from, 0, sizeof(from)); - fromlen = sizeof(from); - - tv.tv_sec = BB_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, - BUFSIZE, 0, - (struct sockaddr *) &from, &fromlen); - - if (len < 0) { - perror_msg("recvfrom"); - break; - } - - timeout = 0; - - if (sa.sin_port == htons(port)) { - sa.sin_port = from.sin_port; - break; - } - - if (sa.sin_port == from.sin_port) { - break; - } - - /* fall-through for bad packets! */ - /* discard the packet - treat as timeout */ - - case 0: - error_msg("timeout"); - - if (!timeout) { - timeout = BB_TFTP_NO_RETRIES; - } else { - timeout--; - } - - if (!timeout) { - len = -1; - error_msg("last timeout"); - } - break; - - default: - perror_msg("select"); - len = -1; + /* exponential backoff with limit */ + waittime_ms += waittime_ms/2; + if (waittime_ms > TFTP_MAXTIMEOUT_MS) { + waittime_ms = TFTP_MAXTIMEOUT_MS; } - } while (timeout && (len >= 0)); - - if (len < 0) { - break; + goto send_again; /* resend last sent pkt */ + default: + /*bb_perror_msg("poll"); - done in safe_poll */ + goto ret; } + process_pkt: + /* Process recv'ed packet */ + opcode = ntohs( ((uint16_t*)rbuf)[0] ); + recv_blk = ntohs( ((uint16_t*)rbuf)[1] ); - /* process received packet */ - - - opcode = ntohs(*((unsigned short *) buf)); - tmp = ntohs(*((unsigned short *) &buf[2])); +#if ENABLE_DEBUG_TFTP + fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk); +#endif - if (BB_TFTP_DEBUG) { - printf("received %d bytes: %04x %04x\n", len, opcode, tmp); + if (opcode == TFTP_ERROR) { + static const char *const errcode_str[] = { + "", + "file not found", + "access violation", + "disk full", + "illegal TFTP operation", + "unknown transfer id", + "file already exists", + "no such user", + "bad option" + }; + + const char *msg = ""; + + if (rbuf[4] != '\0') { + msg = &rbuf[4]; + rbuf[tftp_bufsize - 1] = '\0'; + } else if (recv_blk < ARRAY_SIZE(errcode_str)) { + msg = errcode_str[recv_blk]; + } + bb_error_msg("server error: (%u) %s", recv_blk, msg); + goto ret; } - if (BB_TFTP_GET && (opcode == DATA)) { +#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(&rbuf[2], len - 2, "blksize"); + if (res) { + int blksize = xatoi_u(res); + if (!tftp_blocksize_check(blksize, tftp_bufsize - 4)) { + /* send ERROR 8 to server... */ + /* htons can be impossible to use in const initializer: */ + /*static const uint16_t error_8[2] = { htons(TFTP_ERROR), htons(8) };*/ + /* thus we open-code big-endian layout */ + static const uint8_t error_8[4] = { 0,TFTP_ERROR, 0,8 }; + xsendto(socketfd, error_8, 4, &peer_lsa->sa, peer_lsa->len); + bb_error_msg("server proposes bad blksize %d, exiting", blksize); + goto ret; + } +#if ENABLE_DEBUG_TFTP + fprintf(stderr, "using blksize %u\n", + blksize); +#endif + tftp_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." */ + } - if (tmp == block_nr) { - len = write(localfd, &buf[4], len - 4); + bb_error_msg("blksize is not supported by server" + " - reverting to 512"); + tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4; + } +#endif + /* block_nr is already advanced to next block# we expect + * to get / block# we are about to send next time */ + if (CMD_GET(cmd) && (opcode == TFTP_DATA)) { + if (recv_blk == block_nr) { + len = full_write(localfd, &rbuf[4], len - 4); if (len < 0) { - perror_msg("write"); - break; + bb_perror_msg(bb_msg_write_error); + goto ret; } - - if (len != (BUFSIZE - 4)) { - finished++; + if (len != (tftp_bufsize - 4)) { + finished = 1; } - - opcode = ACK; - continue; + continue; /* send ACK */ } - } - - if (BB_TFTP_PUT && (opcode == ACK)) { - - if (tmp == (block_nr - 1)) { - if (finished) { - break; - } - - opcode = DATA; + if (recv_blk == (block_nr - 1)) { + /* Server lost our TFTP_ACK. Resend it */ + block_nr = recv_blk; continue; } } - if (opcode == ERROR) { - char *msg = NULL; - - if (buf[4] != '\0') { - msg = &buf[4]; - buf[BUFSIZE - 1] = '\0'; - } else if (tmp < (sizeof(tftp_error_msg) / sizeof(char *))) { - msg = (char *) tftp_error_msg[tmp]; - } - - if (msg) { - error_msg("server says: %s", msg); + if (CMD_PUT(cmd) && (opcode == TFTP_ACK)) { + /* did server ACK our last DATA pkt? */ + if (recv_blk == (uint16_t) (block_nr - 1)) { + if (finished) + goto ret; + continue; /* send next block */ } - - break; } + /* 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 + */ } - - close(socketfd); - - return finished ? EXIT_SUCCESS : EXIT_FAILURE; + ret: + if (ENABLE_FEATURE_CLEAN_UP) { + close(socketfd); + free(xbuf); + free(rbuf); + } + return finished == 0; /* returns 1 on failure */ } +int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tftp_main(int argc, char **argv) { - char *cp, *s; - char *serverstr; - struct hostent *host; - char *serverfile; - char *localfile; - int cmd, flags, fd, bad; - - host = (void *) serverstr = serverfile = localfile = NULL; - flags = cmd = 0; - bad = 1; - - if (argc > 3) { - if (BB_TFTP_GET && (strcmp(argv[1], "get") == 0)) { - cmd = BB_TFTP_GET; - flags = O_WRONLY | O_CREAT; - serverstr = argv[2]; - localfile = argv[3]; - } - - if (BB_TFTP_PUT && (strcmp(argv[1], "put") == 0)) { - cmd = BB_TFTP_PUT; - flags = O_RDONLY; - localfile = argv[2]; - serverstr = argv[3]; + len_and_sockaddr *peer_lsa; + const char *localfile = NULL; + const char *remotefile = NULL; +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + const char *sblocksize = NULL; +#endif + int port; + USE_GETPUT(int cmd;) + int fd = -1; + int flags = 0; + int result; + int blocksize = TFTP_BLOCKSIZE_DEFAULT; + + /* -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(cmd =) getopt32(argv, + USE_FEATURE_TFTP_GET("g") USE_FEATURE_TFTP_PUT("p") + "l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"), + &localfile, &remotefile + USE_FEATURE_TFTP_BLOCKSIZE(, &sblocksize)); + argv += optind; + + flags = O_RDONLY; + if (CMD_GET(cmd)) + flags = O_WRONLY | O_CREAT | O_TRUNC; + +#if ENABLE_FEATURE_TFTP_BLOCKSIZE + if (sblocksize) { + blocksize = xatoi_u(sblocksize); + if (!tftp_blocksize_check(blocksize, 0)) { + return EXIT_FAILURE; } - } +#endif - if (!(cmd & (BB_TFTP_GET | BB_TFTP_PUT))) { - show_usage(); + if (!localfile) + localfile = remotefile; + if (!remotefile) + remotefile = localfile; + /* Error if filename or host is not known */ + if (!remotefile || !argv[0]) + bb_show_usage(); + + fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO; + if (!LONE_DASH(localfile)) { + fd = xopen(localfile, flags); } - for (cp = serverstr; *cp != '\0'; cp++) - if (*cp == ':') - break; - - if (*cp == ':') { - - serverfile = cp + 1; + port = bb_lookup_port(argv[1], "udp", 69); + peer_lsa = xhost2sockaddr(argv[0], port); - s = xstrdup(serverstr); - s[cp - serverstr] = '\0'; - - if ((host = gethostbyname(s))) { - bad = 0; - } - - free(s); - } - if (bad) { - error_msg_and_die("bad \"server:file\" combination"); - } +#if ENABLE_DEBUG_TFTP + fprintf(stderr, "using server '%s', remotefile '%s', localfile '%s'\n", + xmalloc_sockaddr2dotted(&peer_lsa->sa), + remotefile, localfile); +#endif - if (BB_TFTP_DEBUG) { - printf("using server \"%s\", serverfile \"%s\"," - "localfile \"%s\".\n", - inet_ntoa(*((struct in_addr *) host->h_addr)), - serverfile, localfile); - } + result = tftp( USE_GETPUT(cmd,) peer_lsa, remotefile, fd, port, blocksize); - if ((fd = open(localfile, flags, 0644)) < 0) { - perror_msg_and_die("local file"); + if (ENABLE_FEATURE_CLEAN_UP) + close(fd); + if (result != EXIT_SUCCESS && !LONE_DASH(localfile) && CMD_GET(cmd)) { + unlink(localfile); } - - flags = tftp(cmd, host, serverfile, fd, 69); - - close(fd); - - return flags; + return result; } + +#endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */