/* vi: set sw=4 ts=4: */ /* * 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 * * Parts of the code based on: * * atftp: Copyright (C) 2000 Jean-Pierre Lefebvre * and Remi Lefebvre * * utftp: Copyright (C) 1999 Uwe Ohse * * tftpd added by Denys Vlasenko & Vladimir Dronnikov * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ //config:config TFTP //config: bool "tftp (11 kb)" //config: default y //config: help //config: Trivial File Transfer Protocol client. TFTP is usually used //config: for simple, small transfers such as a root image //config: for a network-enabled bootloader. //config: //config:config FEATURE_TFTP_PROGRESS_BAR //config: bool "Enable progress bar" //config: default y //config: depends on TFTP //config: //config:config FEATURE_TFTP_HPA_COMPAT //config: bool "tftp-hpa compat (support -c get/put FILE)" //config: default y //config: depends on TFTP //config: //config:config TFTPD //config: bool "tftpd (10 kb)" //config: default y //config: help //config: Trivial File Transfer Protocol server. //config: It expects that stdin is a datagram socket and a packet //config: is already pending on it. It will exit after one transfer. //config: In other words: it should be run from inetd in nowait mode, //config: or from udpsvd. Example: "udpsvd -E 0 69 tftpd DIR" //config: //config:config FEATURE_TFTP_GET //config: bool "Enable 'tftp get' and/or tftpd upload code" //config: default y //config: depends on TFTP || TFTPD //config: help //config: Add support for the GET command within the TFTP client. This allows //config: a client to retrieve a file from a TFTP server. //config: Also enable upload support in tftpd, if tftpd is selected. //config: //config: Note: this option does _not_ make tftpd capable of download //config: (the usual operation people need from it)! //config: //config:config FEATURE_TFTP_PUT //config: bool "Enable 'tftp put' and/or tftpd download code" //config: default y //config: depends on TFTP || TFTPD //config: help //config: Add support for the PUT command within the TFTP client. This allows //config: a client to transfer a file to a TFTP server. //config: Also enable download support in tftpd, if tftpd is selected. //config: //config:config FEATURE_TFTP_BLOCKSIZE //config: bool "Enable 'blksize' and 'tsize' protocol options" //config: default y //config: depends on TFTP || TFTPD //config: help //config: Allow tftp to specify block size, and tftpd to understand //config: "blksize" and "tsize" options. //config: //config:config TFTP_DEBUG //config: bool "Enable debug" //config: default n //config: depends on TFTP || TFTPD //config: help //config: Make tftp[d] print debugging messages on stderr. //config: This is useful if you are diagnosing a bug in tftp[d]. //applet:#if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT //applet:IF_TFTP(APPLET(tftp, BB_DIR_USR_BIN, BB_SUID_DROP)) //applet:IF_TFTPD(APPLET(tftpd, BB_DIR_USR_SBIN, BB_SUID_DROP)) //applet:#endif //kbuild:lib-$(CONFIG_TFTP) += tftp.o //kbuild:lib-$(CONFIG_TFTPD) += tftp.o //usage:#define tftp_trivial_usage //usage: "[OPTIONS] HOST [PORT]" //usage:#define tftp_full_usage "\n\n" //usage: "Transfer a file from/to tftp server\n" //usage: "\n -l FILE Local FILE" //usage: "\n -r FILE Remote FILE" //usage: IF_FEATURE_TFTP_GET( //usage: "\n -g Get file" //usage: ) //usage: IF_FEATURE_TFTP_PUT( //usage: "\n -p Put file" //usage: ) //usage: IF_FEATURE_TFTP_BLOCKSIZE( //usage: "\n -b SIZE Transfer blocks in bytes" //usage: ) ///////: "\n -m STR Accepted and ignored ('-m binary' compat with tftp-hpa 5.2)" //usage: //usage:#define tftpd_trivial_usage //usage: "[-crl] [-u USER] [DIR]" //usage:#define tftpd_full_usage "\n\n" //usage: "Transfer a file on tftp client's request\n" //usage: "\n" //usage: "tftpd should be used as an inetd service.\n" //usage: "tftpd's line for inetd.conf:\n" //usage: " 69 dgram udp nowait root tftpd tftpd -l /files/to/serve\n" //usage: "It also can be ran from udpsvd:\n" //usage: " udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve\n" //usage: "\n -r Prohibit upload" //usage: "\n -c Allow file creation via upload" //usage: "\n -u USER Access files as USER" //usage: "\n -l Log to syslog (inetd mode requires this)" #include "libbb.h" #include "common_bufsiz.h" #include #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" /* Was 50 ms but users asked to bump it up a bit */ #define TFTP_TIMEOUT_MS 100 #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 /* 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, TFTPD_OPT_l = (1 << 11) * ENABLE_TFTPD, }; #if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT #define IF_GETPUT(...) #define CMD_GET(cmd) 1 #define CMD_PUT(cmd) 0 #elif !ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT #define IF_GETPUT(...) #define CMD_GET(cmd) 0 #define CMD_PUT(cmd) 1 #else #define IF_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]; struct passwd *pw; /* Used in tftpd_main() for initial packet */ /* Some HP PA-RISC firmware always sends fixed 516-byte requests */ char block_buf[516]; char block_buf_tail[1]; #if ENABLE_FEATURE_TFTP_PROGRESS_BAR off_t pos; off_t size; const char *file; bb_progress_t pmt; #endif } FIX_ALIASING; #define G (*(struct globals*)bb_common_bufsiz1) #define INIT_G() do { \ setup_common_bufsiz(); \ BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \ } while (0) #define G_error_pkt_reason (G.error_pkt[3]) #define G_error_pkt_str ((char*)(G.error_pkt + 4)) #if ENABLE_FEATURE_TFTP_PROGRESS_BAR && ENABLE_FEATURE_TFTP_BLOCKSIZE static void tftp_progress_update(void) { bb_progress_update(&G.pmt, 0, G.pos, G.size); } static void tftp_progress_init(void) { bb_progress_init(&G.pmt, G.file); tftp_progress_update(); } static void tftp_progress_done(void) { if (is_bb_progress_inited(&G.pmt)) { tftp_progress_update(); bb_putchar_stderr('\n'); bb_progress_free(&G.pmt); } } #else # define tftp_progress_update() ((void)0) # define tftp_progress_init() ((void)0) # define tftp_progress_done() ((void)0) #endif #if ENABLE_FEATURE_TFTP_BLOCKSIZE static int tftp_blksize_check(const char *blksize_str, int maxsize) { /* Check if the blksize is valid: * RFC2348 says between 8 and 65464, * but our implementation makes it impossible * 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; } # if ENABLE_TFTP_DEBUG bb_info_msg("using blksize %u", blksize); # endif return blksize; } static char *tftp_get_option(const char *option, char *buf, int len) { int opt_val = 0; int opt_found = 0; int k; /* buf points to: * "opt_nameopt_valopt_name2opt_val2..." */ while (len > 0) { /* Make sure 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) { /* it's "name" part */ if (strcasecmp(buf, option) == 0) { opt_found = 1; } } else if (opt_found) { return buf; } k++; buf += k; len -= k; opt_val ^= 1; } return NULL; } #endif static int tftp_protocol( /* NULL if tftp, !NULL if tftpd: */ len_and_sockaddr *our_lsa, len_and_sockaddr *peer_lsa, const char *local_file IF_TFTP(, const char *remote_file) #if !ENABLE_TFTP # define remote_file NULL #endif /* 1 for tftp; 1/0 for tftpd depending whether client asked about it: */ IF_FEATURE_TFTP_BLOCKSIZE(, int want_transfer_size) IF_FEATURE_TFTP_BLOCKSIZE(, int blksize)) { #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; IF_FEATURE_TFTP_BLOCKSIZE(smallint expect_OACK = 0;) smallint finished = 0; uint16_t opcode; uint16_t block_nr; uint16_t recv_blk; int local_fd = -1; 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. * * We must keep the transmit and receive buffers separate * in case we rcv a garbage pkt - 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); 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 (G_error_pkt_reason || G_error_pkt_str[0]) goto send_err_pkt; if (G.pw) { change_identity(G.pw); /* initgroups, setgid, setuid */ } } /* Examples of network traffic. * Note two cases when ACKs with block# of 0 are sent. * * Download without options: * tftp -> "\0\1FILENAME\0octet\0" * "\0\3\0\1FILEDATA..." <- tftpd * tftp -> "\0\4\0\1" * ... * Download with option of blksize 16384: * tftp -> "\0\1FILENAME\0octet\0blksize\00016384\0" * "\0\6blksize\00016384\0" <- tftpd * tftp -> "\0\4\0\0" * "\0\3\0\1FILEDATA..." <- tftpd * tftp -> "\0\4\0\1" * ... * Upload without options: * tftp -> "\0\2FILENAME\0octet\0" * "\0\4\0\0" <- tftpd * tftp -> "\0\3\0\1FILEDATA..." * "\0\4\0\1" <- tftpd * ... * Upload with option of blksize 16384: * tftp -> "\0\2FILENAME\0octet\0blksize\00016384\0" * "\0\6blksize\00016384\0" <- tftpd * tftp -> "\0\3\0\1FILEDATA..." * "\0\4\0\1" <- tftpd * ... */ block_nr = 1; cp = xbuf + 2; if (!ENABLE_TFTP || our_lsa) { /* tftpd */ /* Open file (must be after changing user) */ int open_mode = O_RDONLY; if (CMD_GET(option_mask32)) { open_mode = O_WRONLY | O_TRUNC | O_CREAT; if ((option_mask32 & (TFTPD_OPT+TFTPD_OPT_c)) == TFTPD_OPT) { /* tftpd without -c */ open_mode = O_WRONLY | O_TRUNC; } } local_fd = open(local_file, open_mode, 0666); if (local_fd < 0) { /* sanitize name, it came from untrusted remote side */ unsigned char *p = (void *) local_file; while (*p) { if (*p < ' ') *p = '?'; p++; } bb_perror_msg("can't open '%s'", local_file); G_error_pkt_reason = ERR_NOFILE; strcpy(G_error_pkt_str, "can't open file"); goto send_err_pkt_nomsg; } /* gcc 4.3.1 would NOT optimize it out as it should! */ #if ENABLE_FEATURE_TFTP_BLOCKSIZE if (blksize != TFTP_BLKSIZE_DEFAULT || want_transfer_size) { /* 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 if (CMD_GET(option_mask32)) { /* It's upload and we don't send OACK. * We must ACK 1st packet (with filename) * as if it is "block 0" */ block_nr = 0; } } else { /* tftp */ if (CMD_PUT(option_mask32)) { local_fd = STDIN_FILENO; if (local_file) local_fd = xopen(local_file, O_RDONLY); } /* Removing #if, 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); if (len + 3 + sizeof("octet") >= io_bufsize) { bb_simple_error_msg("remote filename is too long"); goto ret; } cp = stpcpy(cp, remote_file) + 1; /* add "mode" part of the packet */ cp = stpcpy(cp, "octet") + 1; # if ENABLE_FEATURE_TFTP_BLOCKSIZE if (blksize == TFTP_BLKSIZE_DEFAULT && !want_transfer_size) goto send_pkt; /* Need to add option to pkt */ if ((&xbuf[io_bufsize - 1] - cp) < sizeof("blksize NNNNN tsize ") + sizeof(off_t)*3) { bb_simple_error_msg("remote filename is too long"); goto ret; } expect_OACK = 1; # endif #endif /* ENABLE_TFTP */ #if ENABLE_FEATURE_TFTP_BLOCKSIZE add_blksize_opt: if (blksize != TFTP_BLKSIZE_DEFAULT) { /* add "blksize", , blksize, */ strcpy(cp, "blksize"); cp += sizeof("blksize"); cp += snprintf(cp, 6, "%d", blksize) + 1; } if (want_transfer_size) { /* add "tsize", , size, (see RFC2349) */ /* if tftp and downloading, we send "0" (local_fd is not open yet) * and this makes server to send "tsize" option with the size */ /* if tftp and uploading, we send file size (maybe dont, to not confuse old servers???) */ /* if tftpd and downloading, we are answering to client's request */ /* if tftpd and uploading: !want_transfer_size, this code is not executed */ struct stat st; strcpy(cp, "tsize"); cp += sizeof("tsize"); st.st_size = 0; if (local_fd >= 0) fstat(local_fd, &st); cp += sprintf(cp, "%"OFF_FMT"u", (off_t)st.st_size) + 1; # if ENABLE_FEATURE_TFTP_PROGRESS_BAR /* Save for progress bar. If 0 (tftp downloading), * we look at server's reply later */ G.size = st.st_size; if (remote_file && st.st_size) tftp_progress_init(); # endif } #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) { /* Build ACK or DATA */ cp = xbuf + 2; *((uint16_t*)cp) = htons(block_nr); cp += 2; 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 (len != blksize) { finished = 1; } cp += len; IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += len;) } 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 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len); #if ENABLE_FEATURE_TFTP_PROGRESS_BAR if (is_bb_progress_inited(&G.pmt)) tftp_progress_update(); #endif /* 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) { tftp_progress_done(); bb_simple_error_msg("timeout"); goto ret; /* no err packet sent */ } /* exponential backoff with limit */ waittime_ms += waittime_ms/2; if (waittime_ms > TFTP_MAXTIMEOUT_MS) { waittime_ms = TFTP_MAXTIMEOUT_MS; } 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; } } /* 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) { 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); } bb_error_msg("server error: (%u) %s", recv_blk, msg); goto ret; } #if ENABLE_FEATURE_TFTP_BLOCKSIZE if (expect_OACK) { expect_OACK = 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) { G_error_pkt_reason = ERR_BAD_OPT; goto send_err_pkt; } io_bufsize = blksize + 4; } # if ENABLE_FEATURE_TFTP_PROGRESS_BAR if (remote_file && G.size == 0) { /* if we don't know it yet */ res = tftp_get_option("tsize", &rbuf[2], len - 2); if (res) { G.size = bb_strtoull(res, NULL, 10); if (G.size) tftp_progress_init(); } } # endif if (CMD_GET(option_mask32)) { /* We'll send ACK for OACK, * such ACK has "block no" of 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 (blksize != TFTP_BLKSIZE_DEFAULT) bb_simple_error_msg("falling back to blocksize "TFTP_BLKSIZE_DEFAULT_STR); blksize = TFTP_BLKSIZE_DEFAULT; io_bufsize = TFTP_BLKSIZE_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(option_mask32) && (opcode == TFTP_DATA)) { if (recv_blk == block_nr) { int sz; if (local_fd == -1) { local_fd = STDOUT_FILENO; if (local_file) local_fd = xopen(local_file, O_WRONLY | O_TRUNC | O_CREAT); } sz = full_write(local_fd, &rbuf[4], len - 4); if (sz != len - 4) { strcpy(G_error_pkt_str, bb_msg_write_error); G_error_pkt_reason = ERR_WRITE; goto send_err_pkt; } if (sz != blksize) { finished = 1; } IF_FEATURE_TFTP_PROGRESS_BAR(G.pos += sz;) continue; /* send ACK */ } /* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */ #if 0 if (recv_blk == (block_nr - 1)) { /* Server lost our TFTP_ACK. Resend it */ block_nr = recv_blk; continue; } #endif } 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 be 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); } if (!finished) goto err; return EXIT_SUCCESS; send_read_err_pkt: strcpy(G_error_pkt_str, bb_msg_read_error); send_err_pkt: if (G_error_pkt_str[0]) bb_simple_error_msg(G_error_pkt_str); send_err_pkt_nomsg: G.error_pkt[1] = TFTP_ERROR; xsendto(socket_fd, G.error_pkt, 4 + 1 + strlen(G_error_pkt_str), &peer_lsa->u.sa, peer_lsa->len); err: if (local_fd >= 0 && CMD_GET(option_mask32) && local_file) unlink(local_file); return EXIT_FAILURE; #undef remote_file } #if ENABLE_TFTP int tftp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int tftp_main(int argc UNUSED_PARAM, char **argv) { 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 port; INIT_G(); if (ENABLE_FEATURE_TFTP_HPA_COMPAT) { /* As of 2019, common tftp client in Linux distros * is one maintained by H. Peter Anvin: * I've seen "tftp-hpa 5.2" version. * Make the following command work: * "tftp HOST [PORT] -m binary -c get/put FILE" * by mangling it into "....... -g/-p -r FILE" * and accepting and ignoring -m STR option. */ unsigned i = 1; while (argv[i]) { /* Accept not only -c, but also * -lc, -cl, -llcclcllcc etc: * "-l Literal mode (do not recognize HOST:FILE)" * since we do not recognize that syntax anyway, * might as well allow the option. */ if (argv[i][0] == '-' && strchr(argv[i], 'c') /*&& argv[i][1+strspn(argv[i]+1, "lc")] == '\0'*/ ) { if (!argv[++i]) break; if (strcmp(argv[i], "get") == 0) { argv[i-1] = (char*)"-g"; argv[i] = (char*)"-r"; break; } if (strcmp(argv[i], "put") == 0) { argv[i-1] = (char*)"-p"; argv[i] = (char*)"-r"; break; } } i++; } } getopt32(argv, "^" IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p") "l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:") IF_FEATURE_TFTP_HPA_COMPAT("m:") "\0" /* -p or -g is mandatory, and they are mutually exclusive */ IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:") IF_GETPUT("g--p:p--g:"), &local_file, &remote_file IF_FEATURE_TFTP_BLOCKSIZE(, &blksize_str) IF_FEATURE_TFTP_HPA_COMPAT(, NULL) ); 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 if (remote_file) { if (!local_file) { const char *slash = strrchr(remote_file, '/'); local_file = slash ? slash + 1 : remote_file; } } else { remote_file = local_file; } /* Error if filename or host is not known */ if (!remote_file || !argv[0]) bb_show_usage(); port = bb_lookup_port(argv[1], "udp", 69); peer_lsa = xhost2sockaddr(argv[0], port); # 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 # if ENABLE_FEATURE_TFTP_PROGRESS_BAR G.file = remote_file; # endif result = tftp_protocol( NULL /*our_lsa*/, peer_lsa, (LONE_DASH(local_file) ? NULL : local_file), remote_file IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */) IF_FEATURE_TFTP_BLOCKSIZE(, blksize) ); tftp_progress_done(); return result; } #endif /* ENABLE_TFTP */ #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 *mode, *user_opt; char *local_file = local_file; const char *error_msg; int opt, result, opcode; IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;) IF_FEATURE_TFTP_BLOCKSIZE(int want_transfer_size = 0;) 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 */ } 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:l", &user_opt) << 8); argv += optind; if (opt & TFTPD_OPT_l) { openlog(applet_name, LOG_PID, LOG_DAEMON); logmode = LOGMODE_SYSLOG; } if (opt & TFTPD_OPT_u) { /* Must be before xchroot */ G.pw = xgetpwnam(user_opt); } if (argv[0]) { xchroot(argv[0]); } result = recv_from_to(STDIN_FILENO, G.block_buf, sizeof(G.block_buf) + 1, /* ^^^ sizeof+1 to reliably detect oversized input */ 0 /* flags */, &peer_lsa->u.sa, &our_lsa->u.sa, our_lsa->len); error_msg = "malformed packet"; opcode = ntohs(*(uint16_t*)G.block_buf); if (result < 4 || result > sizeof(G.block_buf) /*|| G.block_buf[result-1] != '\0' - bug compatibility, see below */ || (IF_FEATURE_TFTP_PUT(opcode != TFTP_RRQ) /* not download */ IF_GETPUT(&&) IF_FEATURE_TFTP_GET(opcode != TFTP_WRQ) /* not upload */ ) ) { goto err; } /* Some HP PA-RISC firmware always sends fixed 516-byte requests, * with trailing garbage. * Support that by not requiring NUL to be the last byte (see above). * To make strXYZ() ops safe, force NUL termination: */ G.block_buf_tail[0] = '\0'; local_file = G.block_buf + 2; if (local_file[0] == '.' || strstr(local_file, "/.")) { error_msg = "dot in file name"; goto err; } mode = local_file + strlen(local_file) + 1; /* RFC 1350 says mode string is case independent */ if (mode >= G.block_buf + result || strcasecmp(mode, "octet") != 0) { error_msg = "mode is not 'octet'"; goto err; } # if ENABLE_FEATURE_TFTP_BLOCKSIZE { char *res; char *opt_str = mode + sizeof("octet"); int opt_len = G.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) { G_error_pkt_reason = ERR_BAD_OPT; /* will just send error pkt */ goto do_proto; } } if (opcode != TFTP_WRQ /* download? */ /* did client ask us about file size? */ && tftp_get_option("tsize", opt_str, opt_len) ) { want_transfer_size = 1; } } } # endif if (!ENABLE_FEATURE_TFTP_PUT || opcode == TFTP_WRQ) { if (opt & TFTPD_OPT_r) { /* This would mean "disk full" - not true */ /*G_error_pkt_reason = ERR_WRITE;*/ error_msg = bb_msg_write_error; goto err; } IF_GETPUT(option_mask32 |= TFTP_OPT_GET;) /* will receive file's data */ } else { IF_GETPUT(option_mask32 |= TFTP_OPT_PUT;) /* will send file's data */ } /* NB: if G_error_pkt_str or G_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 IF_TFTP(, NULL /*remote_file*/) IF_FEATURE_TFTP_BLOCKSIZE(, want_transfer_size) IF_FEATURE_TFTP_BLOCKSIZE(, blksize) ); return result; err: strcpy(G_error_pkt_str, error_msg); goto do_proto; } #endif /* ENABLE_TFTPD */ #endif /* ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT */