tftp: code diet, and I think retransmits were broken.
function old new delta static.errcode_str - 32 +32 tftp_main 359 345 -14 tftp_bb_error_msg 32 - -32 .rodata 130931 130899 -32 tftp 1720 1558 -162 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 0/3 up/down: 32/-240) Total: -208 bytes
This commit is contained in:
Denis Vlasenko
parent
7e84e539de
commit
a04561f5f7
@ -36,17 +36,6 @@
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#define TFTP_ERROR 5
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#define TFTP_OACK 6
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static const char *const tftp_bb_error_msg[] = {
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"Undefined error",
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"File not found",
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"Access violation",
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"Disk full or allocation error",
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"Illegal TFTP operation",
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"Unknown transfer ID",
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"File already exists",
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"No such user"
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};
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#if ENABLE_FEATURE_TFTP_GET && !ENABLE_FEATURE_TFTP_PUT
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#define USE_GETPUT(a)
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#define CMD_GET(cmd) 1
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@ -62,7 +51,7 @@ static const char *const tftp_bb_error_msg[] = {
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#define CMD_PUT(cmd) ((cmd) & 2)
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#endif
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/* NB: in the code below
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* CMD_GET(cmd) and CMD_GET(cmd) are mutually exclusive
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* CMD_GET(cmd) and CMD_PUT(cmd) are mutually exclusive
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*/
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@ -86,7 +75,7 @@ static int tftp_blocksize_check(int blocksize, int bufsize)
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return blocksize;
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}
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static char *tftp_option_get(char *buf, int len, const char * const option)
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static char *tftp_option_get(char *buf, int len, const char *option)
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{
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int opt_val = 0;
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int opt_found = 0;
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@ -94,32 +83,24 @@ static char *tftp_option_get(char *buf, int len, const char * const option)
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while (len > 0) {
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/* Make sure the options are terminated correctly */
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for (k = 0; k < len; k++) {
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if (buf[k] == '\0') {
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break;
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goto nul_found;
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}
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}
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if (k >= len) {
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break;
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}
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return NULL;
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nul_found:
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if (opt_val == 0) {
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if (strcasecmp(buf, option) == 0) {
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opt_found = 1;
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}
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} else {
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if (opt_found) {
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return buf;
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}
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} else if (opt_found) {
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return buf;
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}
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k++;
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buf += k;
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len -= k;
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opt_val ^= 1;
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}
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@ -140,15 +121,15 @@ static int tftp(
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fd_set rfds;
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int socketfd;
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int len;
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int opcode = 0;
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int finished = 0;
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int timeout = TFTP_NUM_RETRIES;
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int send_len;
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USE_FEATURE_TFTP_BLOCKSIZE(smallint want_option_ack = 0;)
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smallint finished = 0;
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uint16_t opcode;
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uint16_t block_nr = 1;
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uint16_t tmp;
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uint16_t recv_blk;
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int timeout = TFTP_NUM_RETRIES;
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char *cp;
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USE_FEATURE_TFTP_BLOCKSIZE(int want_option_ack = 0;)
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unsigned org_port;
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len_and_sockaddr *const from = alloca(offsetof(len_and_sockaddr, sa) + peer_lsa->len);
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@ -168,109 +149,83 @@ static int tftp(
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if (CMD_GET(cmd)) {
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opcode = TFTP_RRQ;
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}
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while (1) {
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cp = xbuf;
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/* first create the opcode part */
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/* (this 16bit store is aligned) */
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*((uint16_t*)cp) = htons(opcode);
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cp += 2;
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/* add filename and mode */
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if (CMD_GET(cmd) ? (opcode == TFTP_RRQ) : (opcode == TFTP_WRQ)) {
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int too_long = 0;
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/* see if the filename fits into xbuf
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* and fill in packet. */
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len = strlen(remotefile) + 1;
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if ((cp + len) >= &xbuf[tftp_bufsize - 1]) {
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too_long = 1;
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} else {
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safe_strncpy(cp, remotefile, len);
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cp += len;
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}
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if (too_long || (&xbuf[tftp_bufsize - 1] - cp) < sizeof("octet")) {
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bb_error_msg("remote filename too long");
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break;
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}
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/* add "mode" part of the package */
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memcpy(cp, "octet", sizeof("octet"));
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cp += sizeof("octet");
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cp = xbuf + 2;
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/* add filename and mode */
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/* fill in packet if the filename fits into xbuf */
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len = strlen(remotefile) + 1;
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if (2 + len + sizeof("octet") >= tftp_bufsize) {
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bb_error_msg("remote filename is too long");
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goto ret;
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}
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strcpy(cp, remotefile);
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cp += len;
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/* add "mode" part of the package */
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strcpy(cp, "octet");
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cp += sizeof("octet");
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#if ENABLE_FEATURE_TFTP_BLOCKSIZE
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len = tftp_bufsize - 4; /* data block size */
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if (len != TFTP_BLOCKSIZE_DEFAULT) {
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if ((&xbuf[tftp_bufsize - 1] - cp) < 15) {
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bb_error_msg("remote filename too long");
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break;
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}
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/* add "blksize" + number of blocks */
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memcpy(cp, "blksize", sizeof("blksize"));
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cp += sizeof("blksize");
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cp += snprintf(cp, 6, "%d", len) + 1;
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want_option_ack = 1;
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}
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len = tftp_bufsize - 4; /* data block size */
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if (len != TFTP_BLOCKSIZE_DEFAULT) {
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/* rfc2348 says that 65464 is a max allowed value */
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if ((&xbuf[tftp_bufsize - 1] - cp) < sizeof("blksize NNNNN")) {
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bb_error_msg("remote filename is too long");
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goto ret;
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}
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/* add "blksize", <nul>, blocksize */
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strcpy(cp, "blksize");
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cp += sizeof("blksize");
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cp += snprintf(cp, 6, "%d", len) + 1;
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want_option_ack = 1;
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}
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#endif
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}
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/* First packet is built, so skip packet generation */
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goto send_pkt;
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/* add ack and data */
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if (CMD_GET(cmd) ? (opcode == TFTP_ACK) : (opcode == TFTP_DATA)) {
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/* TODO: unaligned access! */
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*((uint16_t*)cp) = htons(block_nr);
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cp += 2;
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block_nr++;
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if (CMD_PUT(cmd) && (opcode == TFTP_DATA)) {
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len = full_read(localfd, cp, tftp_bufsize - 4);
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if (len < 0) {
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bb_perror_msg(bb_msg_read_error);
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break;
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}
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if (len != (tftp_bufsize - 4)) {
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finished++;
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}
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cp += len;
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while (1) {
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/* Build ACK or DATA */
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cp = xbuf + 2;
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*((uint16_t*)cp) = htons(block_nr);
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cp += 2;
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block_nr++;
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opcode = TFTP_ACK;
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if (CMD_PUT(cmd)) {
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opcode = TFTP_DATA;
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len = full_read(localfd, cp, tftp_bufsize - 4);
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if (len < 0) {
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bb_perror_msg(bb_msg_read_error);
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goto ret;
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}
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if (len != (tftp_bufsize - 4)) {
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finished = 1;
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}
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cp += len;
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}
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/* send packet */
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send_pkt:
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/* Send packet */
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*((uint16_t*)xbuf) = htons(opcode); /* fill in opcode part */
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timeout = TFTP_NUM_RETRIES; /* re-initialize */
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do {
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len = cp - xbuf;
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while (1) {
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send_len = cp - xbuf;
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/* nb: need to preserve send_len value in code below
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* for potential resend! */
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send_again:
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#if ENABLE_DEBUG_TFTP
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fprintf(stderr, "sending %u bytes\n", len);
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for (cp = xbuf; cp < &xbuf[len]; cp++)
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fprintf(stderr, "sending %u bytes\n", send_len);
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for (cp = xbuf; cp < &xbuf[send_len]; cp++)
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fprintf(stderr, "%02x ", (unsigned char) *cp);
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fprintf(stderr, "\n");
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#endif
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xsendto(socketfd, xbuf, len, &peer_lsa->sa, peer_lsa->len);
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xsendto(socketfd, xbuf, send_len, &peer_lsa->sa, peer_lsa->len);
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/* Was it final ACK? then exit */
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if (finished && (opcode == TFTP_ACK))
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goto ret;
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if (finished && (opcode == TFTP_ACK)) {
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break;
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}
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/* receive packet */
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/* Receive packet */
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recv_again:
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tv.tv_sec = TFTP_TIMEOUT;
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tv.tv_usec = 0;
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FD_ZERO(&rfds);
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FD_SET(socketfd, &rfds);
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switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) {
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unsigned from_port;
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case 1:
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@ -280,7 +235,7 @@ static int tftp(
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&from->sa, &from->len);
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if (len < 0) {
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bb_perror_msg("recvfrom");
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break;
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goto ret;
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}
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from_port = get_nport(&from->sa);
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if (port == org_port) {
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@ -292,57 +247,57 @@ static int tftp(
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}
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if (port != from_port)
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goto recv_again;
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timeout = 0;
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break;
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goto recvd_good;
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case 0:
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bb_error_msg("timeout");
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timeout--;
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if (timeout == 0) {
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len = -1;
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bb_error_msg("last timeout");
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goto ret;
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}
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break;
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bb_error_msg("last timeout" + 5);
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goto send_again; /* resend last sent pkt */
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default:
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bb_perror_msg("select");
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len = -1;
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goto ret;
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}
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} /* while we don't see recv packet with correct port# */
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} while (timeout && (len >= 0));
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if (finished || (len < 0)) {
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break;
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}
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/* process received packet */
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/* (both accesses seems to be aligned) */
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/* Process recv'ed packet */
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recvd_good:
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opcode = ntohs( ((uint16_t*)rbuf)[0] );
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tmp = ntohs( ((uint16_t*)rbuf)[1] );
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recv_blk = ntohs( ((uint16_t*)rbuf)[1] );
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#if ENABLE_DEBUG_TFTP
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fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, tmp);
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fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, recv_blk);
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#endif
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if (opcode == TFTP_ERROR) {
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const char *msg = NULL;
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static const char *const errcode_str[] = {
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"",
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"file not found",
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"access violation",
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"disk full",
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"illegal TFTP operation",
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"unknown transfer id",
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"file already exists",
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"no such user",
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};
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enum { NUM_ERRCODE = sizeof(errcode_str) / sizeof(errcode_str[0]) };
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const char *msg = "";
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if (rbuf[4] != '\0') {
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msg = &rbuf[4];
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rbuf[tftp_bufsize - 1] = '\0';
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} else if (tmp < (sizeof(tftp_bb_error_msg)
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/ sizeof(char *))) {
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msg = tftp_bb_error_msg[tmp];
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} else if (recv_blk < NUM_ERRCODE) {
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msg = errcode_str[recv_blk];
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}
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if (msg) {
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bb_error_msg("server says: %s", msg);
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}
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break;
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bb_error_msg("server error: (%u) %s", recv_blk, msg);
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goto ret;
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}
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#if ENABLE_FEATURE_TFTP_BLOCKSIZE
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if (want_option_ack) {
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want_option_ack = 0;
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if (opcode == TFTP_OACK) {
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@ -350,87 +305,81 @@ static int tftp(
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char *res;
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res = tftp_option_get(&rbuf[2], len - 2, "blksize");
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if (res) {
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int blksize = xatoi_u(res);
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if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) {
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if (CMD_PUT(cmd)) {
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opcode = TFTP_DATA;
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} else {
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opcode = TFTP_ACK;
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}
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#if ENABLE_DEBUG_TFTP
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fprintf(stderr, "using blksize %u\n",
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blksize);
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#endif
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tftp_bufsize = blksize + 4;
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block_nr = 0;
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continue;
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if (!tftp_blocksize_check(blksize, tftp_bufsize - 4)) {
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bb_error_msg("server proposes bad blksize %d, exiting", blksize);
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// FIXME: must also send ERROR 8 to server...
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goto ret;
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}
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#if ENABLE_DEBUG_TFTP
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fprintf(stderr, "using blksize %u\n",
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blksize);
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#endif
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tftp_bufsize = blksize + 4;
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block_nr = 0; // TODO: explain why???
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continue;
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}
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/* FIXME:
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* we should send ERROR 8 */
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bb_error_msg("bad server option");
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break;
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/* rfc2347:
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* "An option not acknowledged by the server
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* must be ignored by the client and server
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* as if it were never requested." */
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}
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bb_error_msg("warning: blksize not supported by server"
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" - reverting to 512");
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bb_error_msg("blksize is not supported by server"
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" - reverting to 512");
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tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4;
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}
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#endif
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/* block_nr is already advanced to next block# we expect
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* to get / block# we are about to send next time */
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if (CMD_GET(cmd) && (opcode == TFTP_DATA)) {
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if (tmp == block_nr) {
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if (recv_blk == block_nr) {
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len = full_write(localfd, &rbuf[4], len - 4);
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if (len < 0) {
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bb_perror_msg(bb_msg_write_error);
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break;
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goto ret;
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}
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if (len != (tftp_bufsize - 4)) {
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finished++;
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finished = 1;
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}
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opcode = TFTP_ACK;
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continue;
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continue; /* send ACK */
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}
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/* in case the last ack disappeared into the ether */
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if (tmp == (block_nr - 1)) {
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--block_nr;
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opcode = TFTP_ACK;
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continue;
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// tmp==(block_nr-1) and (tmp+1)==block_nr is always same, I think. wtf?
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} else if (tmp + 1 == block_nr) {
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if (recv_blk == (block_nr - 1)) {
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/* Server lost our TFTP_ACK. Resend it */
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block_nr = tmp;
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opcode = TFTP_ACK;
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block_nr = recv_blk;
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continue;
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}
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}
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}
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if (CMD_PUT(cmd) && (opcode == TFTP_ACK)) {
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if (tmp == (uint16_t) (block_nr - 1)) {
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if (finished) {
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break;
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}
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opcode = TFTP_DATA;
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continue;
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/* did server ACK our last DATA pkt? */
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if (recv_blk == (uint16_t) (block_nr - 1)) {
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if (finished)
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goto ret;
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continue; /* send next block */
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}
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}
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/* Awww... recv'd packet is not recognized! */
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goto recv_again;
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/* why recv_again? - rfc1123 says:
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* "The sender (i.e., the side originating the DATA packets)
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* must never resend the current DATA packet on receipt
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* of a duplicate ACK".
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* DATA pkts are resent ONLY on timeout.
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* Thus "goto send_again" will ba a bad mistake above.
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* See:
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* http://en.wikipedia.org/wiki/Sorcerer's_Apprentice_Syndrome
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*/
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}
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ret:
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if (ENABLE_FEATURE_CLEAN_UP) {
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close(socketfd);
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free(xbuf);
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free(rbuf);
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}
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return finished ? EXIT_SUCCESS : EXIT_FAILURE;
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return finished == 0; /* returns 1 on failure */
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}
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int tftp_main(int argc, char **argv);
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@ -458,6 +407,7 @@ int tftp_main(int argc, char **argv)
|
||||
"l:r:" USE_FEATURE_TFTP_BLOCKSIZE("b:"),
|
||||
&localfile, &remotefile
|
||||
USE_FEATURE_TFTP_BLOCKSIZE(, &sblocksize));
|
||||
argv += optind;
|
||||
|
||||
flags = O_RDONLY;
|
||||
if (CMD_GET(cmd))
|
||||
@ -472,25 +422,26 @@ int tftp_main(int argc, char **argv)
|
||||
}
|
||||
#endif
|
||||
|
||||
if (localfile == NULL)
|
||||
if (!localfile)
|
||||
localfile = remotefile;
|
||||
if (remotefile == NULL)
|
||||
if (!remotefile)
|
||||
remotefile = localfile;
|
||||
if ((localfile == NULL && remotefile == NULL) || (argv[optind] == NULL))
|
||||
/* Error if filename or host is not known */
|
||||
if (!remotefile || !argv[0])
|
||||
bb_show_usage();
|
||||
|
||||
if (localfile == NULL || LONE_DASH(localfile)) {
|
||||
if (LONE_DASH(localfile)) {
|
||||
fd = CMD_GET(cmd) ? STDOUT_FILENO : STDIN_FILENO;
|
||||
} else {
|
||||
fd = xopen3(localfile, flags, 0644);
|
||||
fd = xopen(localfile, flags);
|
||||
}
|
||||
|
||||
port = bb_lookup_port(argv[optind + 1], "udp", 69);
|
||||
peer_lsa = xhost2sockaddr(argv[optind], port);
|
||||
port = bb_lookup_port(argv[1], "udp", 69);
|
||||
peer_lsa = xhost2sockaddr(argv[0], port);
|
||||
|
||||
#if ENABLE_DEBUG_TFTP
|
||||
fprintf(stderr, "using server \"%s\", "
|
||||
"remotefile \"%s\", localfile \"%s\".\n",
|
||||
"remotefile \"%s\", localfile \"%s\"\n",
|
||||
xmalloc_sockaddr2dotted(&peer_lsa->sa, peer_lsa->len),
|
||||
remotefile, localfile);
|
||||
#endif
|
||||
@ -501,11 +452,10 @@ int tftp_main(int argc, char **argv)
|
||||
#endif
|
||||
peer_lsa, remotefile, fd, port, blocksize);
|
||||
|
||||
if (fd > 1) {
|
||||
if (ENABLE_FEATURE_CLEAN_UP)
|
||||
close(fd);
|
||||
if (CMD_GET(cmd) && result != EXIT_SUCCESS)
|
||||
unlink(localfile);
|
||||
if (ENABLE_FEATURE_CLEAN_UP)
|
||||
close(fd);
|
||||
if (result != EXIT_SUCCESS && !LONE_DASH(localfile) && CMD_GET(cmd)) {
|
||||
unlink(localfile);
|
||||
}
|
||||
return result;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user