hush/networking/tftp.c
Rob Landley d921b2ecc0 Remove bb_ prefixes from xfuncs.c (and a few other places), consolidate
things like xasprintf() into xfuncs.c, remove xprint_file_by_name() (it only
had one user), clean up lots of #includes...  General cleanup pass.  What I've
been doing for the last couple days.

And it conflicts!  I've removed httpd.c from this checkin due to somebody else
touching that file.  It builds for me.  I have to catch a bus.  (Now you know
why I'm looking forward to Mercurial.)
2006-08-03 15:41:12 +00:00

564 lines
12 KiB
C

/* 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 <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>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
* ------------------------------------------------------------------------- */
#include "busybox.h"
#define TFTP_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
#define TFTP_TIMEOUT 5 /* seconds */
#define TFTP_NUM_RETRIES 5 /* number of retries */
static const char * const MODE_OCTET = "octet";
#define MODE_OCTET_LEN 6 /* sizeof(MODE_OCTET)*/
static const char * const OPTION_BLOCKSIZE = "blksize";
#define OPTION_BLOCKSIZE_LEN 8 /* sizeof(OPTION_BLOCKSIZE) */
/* 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
static const char *const 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"
};
#define tftp_cmd_get ENABLE_FEATURE_TFTP_GET
#if ENABLE_FEATURE_TFTP_PUT
# define tftp_cmd_put (tftp_cmd_get+ENABLE_FEATURE_TFTP_PUT)
#else
# define tftp_cmd_put 0
#endif
#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
static int tftp_blocksize_check(int blocksize, int bufsize)
{
/* 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;
}
return blocksize;
}
static char *tftp_option_get(char *buf, int len, const char * const 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') {
break;
}
}
if (k >= len) {
break;
}
if (opt_val == 0) {
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(const int cmd, const struct hostent *host,
const char *remotefile, const int localfd,
const unsigned short port, int tftp_bufsize)
{
struct sockaddr_in sa;
struct sockaddr_in from;
struct timeval tv;
socklen_t fromlen;
fd_set rfds;
int socketfd;
int len;
int opcode = 0;
int finished = 0;
int timeout = TFTP_NUM_RETRIES;
unsigned short block_nr = 1;
unsigned short tmp;
char *cp;
USE_FEATURE_TFTP_BLOCKSIZE(int want_option_ack = 0;)
/* 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);
if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
/* need to unlink the localfile, so don't use xsocket here. */
bb_perror_msg("socket");
return EXIT_FAILURE;
}
len = sizeof(sa);
memset(&sa, 0, len);
xbind(socketfd, (struct sockaddr *)&sa, len);
sa.sin_family = host->h_addrtype;
sa.sin_port = port;
memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr,
sizeof(sa.sin_addr));
/* build opcode */
if (cmd & tftp_cmd_get) {
opcode = TFTP_RRQ;
}
if (cmd & tftp_cmd_put) {
opcode = TFTP_WRQ;
}
while (1) {
cp = buf;
/* first create the opcode part */
*((unsigned short *) cp) = htons(opcode);
cp += 2;
/* add filename and mode */
if (((cmd & tftp_cmd_get) && (opcode == TFTP_RRQ)) ||
((cmd & tftp_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;
}
if (too_long || ((&buf[tftp_bufsize - 1] - cp) < MODE_OCTET_LEN)) {
bb_error_msg("remote filename too long");
break;
}
/* add "mode" part of the package */
memcpy(cp, MODE_OCTET, MODE_OCTET_LEN);
cp += MODE_OCTET_LEN;
#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("remote filename too long");
break;
}
/* add "blksize" + number of blocks */
memcpy(cp, OPTION_BLOCKSIZE, OPTION_BLOCKSIZE_LEN);
cp += OPTION_BLOCKSIZE_LEN;
cp += snprintf(cp, 6, "%d", len) + 1;
want_option_ack = 1;
}
#endif
}
/* add ack and data */
if (((cmd & tftp_cmd_get) && (opcode == TFTP_ACK)) ||
((cmd & tftp_cmd_put) && (opcode == TFTP_DATA))) {
*((unsigned short *) cp) = htons(block_nr);
cp += 2;
block_nr++;
if ((cmd & tftp_cmd_put) && (opcode == TFTP_DATA)) {
len = full_read(localfd, cp, tftp_bufsize - 4);
if (len < 0) {
bb_perror_msg(bb_msg_read_error);
break;
}
if (len != (tftp_bufsize - 4)) {
finished++;
}
cp += len;
}
}
/* send packet */
timeout = TFTP_NUM_RETRIES; /* re-initialize */
do {
len = cp - buf;
#ifdef CONFIG_DEBUG_TFTP
fprintf(stderr, "sending %u bytes\n", len);
for (cp = buf; cp < &buf[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;
}
if (finished && (opcode == TFTP_ACK)) {
break;
}
/* 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(socketfd + 1, &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 == 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 = 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;
}
} 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_DEBUG_TFTP
fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, tmp);
#endif
if (opcode == TFTP_ERROR) {
const 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 = tftp_bb_error_msg[tmp];
}
if (msg) {
bb_error_msg("server says: %s", msg);
}
break;
}
#ifdef CONFIG_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, OPTION_BLOCKSIZE);
if (res) {
int blksize = atoi(res);
if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) {
if (cmd & tftp_cmd_put) {
opcode = TFTP_DATA;
} else {
opcode = TFTP_ACK;
}
#ifdef CONFIG_DEBUG_TFTP
fprintf(stderr, "using %s %u\n", OPTION_BLOCKSIZE,
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;
}
#endif
if ((cmd & tftp_cmd_get) && (opcode == TFTP_DATA)) {
if (tmp == block_nr) {
len = full_write(localfd, &buf[4], len - 4);
if (len < 0) {
bb_perror_msg(bb_msg_write_error);
break;
}
if (len != (tftp_bufsize - 4)) {
finished++;
}
opcode = TFTP_ACK;
continue;
}
/* in case the last ack disappeared into the ether */
if (tmp == (block_nr - 1)) {
--block_nr;
opcode = TFTP_ACK;
continue;
} else if (tmp + 1 == block_nr) {
/* Server lost our TFTP_ACK. Resend it */
block_nr = tmp;
opcode = TFTP_ACK;
continue;
}
}
if ((cmd & tftp_cmd_put) && (opcode == TFTP_ACK)) {
if (tmp == (unsigned short) (block_nr - 1)) {
if (finished) {
break;
}
opcode = TFTP_DATA;
continue;
}
}
}
#ifdef CONFIG_FEATURE_CLEAN_UP
close(socketfd);
free(buf);
#endif
return finished ? EXIT_SUCCESS : EXIT_FAILURE;
}
int tftp_main(int argc, char **argv)
{
struct hostent *host = NULL;
const char *localfile = NULL;
const char *remotefile = NULL;
int port;
int cmd = 0;
int fd = -1;
int flags = 0;
int result;
int blocksize = TFTP_BLOCKSIZE_DEFAULT;
/* figure out what to pass to getopt */
#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
char *sblocksize = NULL;
#define BS "b:"
#define BS_ARG , &sblocksize
#else
#define BS
#define BS_ARG
#endif
#ifdef CONFIG_FEATURE_TFTP_GET
#define GET "g"
#define GET_COMPL ":g"
#else
#define GET
#define GET_COMPL
#endif
#ifdef CONFIG_FEATURE_TFTP_PUT
#define PUT "p"
#define PUT_COMPL ":p"
#else
#define PUT
#define PUT_COMPL
#endif
#if defined(CONFIG_FEATURE_TFTP_GET) && defined(CONFIG_FEATURE_TFTP_PUT)
bb_opt_complementally = GET_COMPL PUT_COMPL ":?g--p:p--g";
#elif defined(CONFIG_FEATURE_TFTP_GET) || defined(CONFIG_FEATURE_TFTP_PUT)
bb_opt_complementally = GET_COMPL PUT_COMPL;
#endif
cmd = bb_getopt_ulflags(argc, argv, GET PUT "l:r:" BS,
&localfile, &remotefile BS_ARG);
cmd &= (tftp_cmd_get | tftp_cmd_put);
#ifdef CONFIG_FEATURE_TFTP_GET
if (cmd == tftp_cmd_get)
flags = O_WRONLY | O_CREAT | O_TRUNC;
#endif
#ifdef CONFIG_FEATURE_TFTP_PUT
if (cmd == tftp_cmd_put)
flags = O_RDONLY;
#endif
#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
if (sblocksize) {
blocksize = atoi(sblocksize);
if (!tftp_blocksize_check(blocksize, 0)) {
return EXIT_FAILURE;
}
}
#endif
if (localfile == NULL)
localfile = remotefile;
if (remotefile == NULL)
remotefile = localfile;
if ((localfile == NULL && remotefile == NULL) || (argv[optind] == NULL))
bb_show_usage();
if (localfile == NULL || strcmp(localfile, "-") == 0) {
fd = (cmd == tftp_cmd_get) ? STDOUT_FILENO : STDIN_FILENO;
} else {
fd = open(localfile, flags, 0644); /* fail below */
}
if (fd < 0) {
bb_perror_msg_and_die("local file");
}
host = xgethostbyname(argv[optind]);
port = bb_lookup_port(argv[optind + 1], "udp", 69);
#ifdef CONFIG_DEBUG_TFTP
fprintf(stderr, "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);
if (!(fd == STDOUT_FILENO || fd == STDIN_FILENO)) {
if (ENABLE_FEATURE_CLEAN_UP)
close(fd);
if (cmd == tftp_cmd_get && result != EXIT_SUCCESS)
unlink(localfile);
}
return (result);
}