* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
* ------------------------------------------------------------------------- */
-#include "busybox.h"
-
+#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 5 /* seconds */
-#define TFTP_NUM_RETRIES 5 /* number of retries */
+#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_OACK 6
#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
-#define USE_GETPUT(a)
+#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(a)
+#define USE_GETPUT(...)
#define CMD_GET(cmd) 0
#define CMD_PUT(cmd) 1
#else
-#define USE_GETPUT(a) a
+#define USE_GETPUT(...) __VA_ARGS__
/* masks coming from getpot32 */
#define CMD_GET(cmd) ((cmd) & 1)
#define CMD_PUT(cmd) ((cmd) & 2)
#endif
-static int tftp(
-#if ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
- const int cmd,
-#endif
+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 timeval tv;
- fd_set rfds;
- int socketfd;
+ struct pollfd pfd[1];
+#define socketfd (pfd[0].fd)
int len;
int send_len;
USE_FEATURE_TFTP_BLOCKSIZE(smallint want_option_ack = 0;)
uint16_t opcode;
uint16_t block_nr = 1;
uint16_t recv_blk;
- int timeout = TFTP_NUM_RETRIES;
+ int retries, waittime_ms;
char *cp;
unsigned org_port;
/* 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;
send_pkt:
/* Send packet */
*((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
- timeout = TFTP_NUM_RETRIES; /* re-initialize */
- while (1) {
- send_len = cp - xbuf;
- /* nb: need to preserve send_len value in code below
- * for potential resend! */
+ 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");
+ 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;
+ xsendto(socketfd, xbuf, send_len, &peer_lsa->sa, peer_lsa->len);
+ /* Was it final ACK? then exit */
+ if (finished && (opcode == TFTP_ACK))
+ goto ret;
- /* Receive packet */
recv_again:
- tv.tv_sec = TFTP_TIMEOUT;
- tv.tv_usec = 0;
- FD_ZERO(&rfds);
- FD_SET(socketfd, &rfds);
- switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) {
- 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;
- }
- 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 (port != from_port)
- goto recv_again;
- goto recvd_good;
- case 0:
- timeout--;
- if (timeout == 0) {
- bb_error_msg("last timeout");
- goto ret;
- }
- bb_error_msg("last timeout" + 5);
- goto send_again; /* resend last sent pkt */
- default:
- bb_perror_msg("select");
+ /* 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;
+ }
+ 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 (port != from_port)
+ goto recv_again;
+ goto process_pkt;
+ case 0:
+ retries--;
+ if (retries == 0) {
+ bb_error_msg("timeout");
goto ret;
}
- } /* while we don't see recv packet with correct port# */
+ /* 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 */
+ default:
+ /*bb_perror_msg("poll"); - done in safe_poll */
+ goto ret;
+ }
+ process_pkt:
/* Process recv'ed packet */
- recvd_good:
opcode = ntohs( ((uint16_t*)rbuf)[0] );
recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
"unknown transfer id",
"file already exists",
"no such user",
+ "bad option"
};
- enum { NUM_ERRCODE = sizeof(errcode_str) / sizeof(errcode_str[0]) };
const char *msg = "";
if (rbuf[4] != '\0') {
msg = &rbuf[4];
rbuf[tftp_bufsize - 1] = '\0';
- } else if (recv_blk < NUM_ERRCODE) {
+ } else if (recv_blk < ARRAY_SIZE(errcode_str)) {
msg = errcode_str[recv_blk];
}
bb_error_msg("server error: (%u) %s", recv_blk, msg);
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);
- // FIXME: must also send ERROR 8 to server...
goto ret;
}
#if ENABLE_DEBUG_TFTP
blksize);
#endif
tftp_bufsize = blksize + 4;
- block_nr = 0; // TODO: explain why???
+ /* Send ACK for OACK ("block" no: 0) */
+ block_nr = 0;
continue;
}
/* rfc2347:
/* Server lost our TFTP_ACK. Resend it */
block_nr = recv_blk;
continue;
- }
+ }
}
if (CMD_PUT(cmd) && (opcode == TFTP_ACK)) {
opt_complementary = "" USE_FEATURE_TFTP_GET("g:") USE_FEATURE_TFTP_PUT("p:")
USE_GETPUT("?g--p:p--g");
- USE_GETPUT(cmd =) getopt32(argc, argv,
+ USE_GETPUT(cmd =) getopt32(argv,
USE_FEATURE_TFTP_GET("g") USE_FEATURE_TFTP_PUT("p")
"l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"),
&localfile, &remotefile
if (!remotefile || !argv[0])
bb_show_usage();
- if (LONE_DASH(localfile)) {
- fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO;
- } else {
+ fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO;
+ if (!LONE_DASH(localfile)) {
fd = xopen(localfile, flags);
}
peer_lsa = xhost2sockaddr(argv[0], port);
#if ENABLE_DEBUG_TFTP
- fprintf(stderr, "using server \"%s\", "
- "remotefile \"%s\", localfile \"%s\"\n",
- xmalloc_sockaddr2dotted(&peer_lsa->sa, peer_lsa->len),
+ fprintf(stderr, "using server '%s', remotefile '%s', localfile '%s'\n",
+ xmalloc_sockaddr2dotted(&peer_lsa->sa),
remotefile, localfile);
#endif
- result = tftp(
-#if ENABLE_FEATURE_TFTP_GET && ENABLE_FEATURE_TFTP_PUT
- cmd,
-#endif
- peer_lsa, remotefile, fd, port, blocksize);
+ result = tftp( USE_GETPUT(cmd,) peer_lsa, remotefile, fd, port, blocksize);
if (ENABLE_FEATURE_CLEAN_UP)
close(fd);
projects / oweals / busybox.git / blobdiff