busybox/networking/tftp.c
Denys Vlasenko f560422fa0 Big cleanup in config help and description
Redundant help texts (one which only repeats the description)
are deleted.

Descriptions and help texts are trimmed.

Some config options are moved, even across menus.

No config option _names_ are changed.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-01-10 14:58:54 +01:00

962 lines
27 KiB
C

/* 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 <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 source tree.
*/
//config:config TFTP
//config: bool "tftp"
//config: default y
//config: help
//config: This enables the Trivial File Transfer Protocol client program. TFTP
//config: is usually used for simple, small transfers such as a root image
//config: for a network-enabled bootloader.
//config:
//config:config TFTPD
//config: bool "tftpd"
//config: default y
//config: help
//config: This enables the Trivial File Transfer Protocol server program.
//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:comment "Common options for tftp/tftpd"
//config: depends on TFTP || TFTPD
//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 FEATURE_TFTP_PROGRESS_BAR
//config: bool "Enable progress bar"
//config: default y
//config: depends on TFTP && FEATURE_TFTP_BLOCKSIZE
//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 of SIZE octets"
//usage: )
//usage:
//usage:#define tftpd_trivial_usage
//usage: "[-cr] [-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 Access files as USER"
//usage: "\n -l Log to syslog (inetd mode requires this)"
#include "libbb.h"
#include "common_bufsiz.h"
#include <syslog.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"
/* 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
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_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_error_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_name<NUL>opt_val<NUL>opt_name2<NUL>opt_val2<NUL>..." */
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 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.
*
* 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 */
}
}
/* Prepare open mode */
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
}
/* 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) */
local_fd = open(local_file, open_mode, 0666);
if (local_fd < 0) {
G_error_pkt_reason = ERR_NOFILE;
strcpy(G_error_pkt_str, "can't open file");
goto send_err_pkt;
}
/* 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 */
/* Open file (must be after changing user) */
local_fd = CMD_GET(option_mask32) ? STDOUT_FILENO : STDIN_FILENO;
if (NOT_LONE_DASH(local_file))
local_fd = xopen(local_file, open_mode);
/* 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) + 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 packet */
strcpy(cp, "octet");
cp += sizeof("octet");
# 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_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", <nul>, blksize, <nul> */
strcpy(cp, "blksize");
cp += sizeof("blksize");
cp += snprintf(cp, 6, "%d", blksize) + 1;
}
if (want_transfer_size) {
/* add "tsize", <nul>, size, <nul> (see RFC2349) */
/* if tftp and downloading, we send "0" (since we opened local_fd with O_TRUNC)
* 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;
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_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_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 = 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 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);
}
return finished == 0; /* returns 1 on failure */
send_read_err_pkt:
strcpy(G_error_pkt_str, bb_msg_read_error);
send_err_pkt:
if (G_error_pkt_str[0])
bb_error_msg("%s", G_error_pkt_str);
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);
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;
IF_GETPUT(int opt;)
INIT_G();
/* -p or -g is mandatory, and they are mutually exclusive */
opt_complementary = "" IF_FEATURE_TFTP_GET("g:") IF_FEATURE_TFTP_PUT("p:")
IF_GETPUT("g--p:p--g:");
IF_GETPUT(opt =) getopt32(argv,
IF_FEATURE_TFTP_GET("g") IF_FEATURE_TFTP_PUT("p")
"l:r:" IF_FEATURE_TFTP_BLOCKSIZE("b:"),
&local_file, &remote_file
IF_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
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,
local_file, remote_file
IF_FEATURE_TFTP_BLOCKSIZE(, 1 /* want_transfer_size */)
IF_FEATURE_TFTP_BLOCKSIZE(, blksize)
);
tftp_progress_done();
if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
unlink(local_file);
}
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) {
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 */