diff options
| -rw-r--r-- | networking/tftp.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/networking/tftp.c b/networking/tftp.c index a62c5d8..2d28973 100644 --- a/networking/tftp.c +++ b/networking/tftp.c @@ -144,7 +144,10 @@ static int tftp(const int cmd, const struct hostent *host, /* 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); + /* We must keep the transmit and receive buffers seperate */ + /* In case we rcv a garbage pkt and we need to rexmit the last pkt */ + char *xbuf = xmalloc(tftp_bufsize += 4); + char *rbuf = xmalloc(tftp_bufsize); if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { /* need to unlink the localfile, so don't use xsocket here. */ @@ -172,7 +175,7 @@ static int tftp(const int cmd, const struct hostent *host, while (1) { - cp = buf; + cp = xbuf; /* first create the opcode part */ *((unsigned short *) cp) = htons(opcode); @@ -184,18 +187,18 @@ static int tftp(const int cmd, const struct hostent *host, { int too_long = 0; - /* see if the filename fits into buf + /* see if the filename fits into xbuf * and fill in packet. */ len = strlen(remotefile) + 1; - if ((cp + len) >= &buf[tftp_bufsize - 1]) { + if ((cp + len) >= &xbuf[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)) { + if (too_long || ((&xbuf[tftp_bufsize - 1] - cp) < MODE_OCTET_LEN)) { bb_error_msg("remote filename too long"); break; } @@ -210,7 +213,7 @@ static int tftp(const int cmd, const struct hostent *host, if (len != TFTP_BLOCKSIZE_DEFAULT) { - if ((&buf[tftp_bufsize - 1] - cp) < 15) { + if ((&xbuf[tftp_bufsize - 1] - cp) < 15) { bb_error_msg("remote filename too long"); break; } @@ -259,15 +262,15 @@ static int tftp(const int cmd, const struct hostent *host, timeout = TFTP_NUM_RETRIES; /* re-initialize */ do { - len = cp - buf; + len = cp - xbuf; #if ENABLE_DEBUG_TFTP fprintf(stderr, "sending %u bytes\n", len); - for (cp = buf; cp < &buf[len]; cp++) + for (cp = xbuf; cp < &xbuf[len]; cp++) fprintf(stderr, "%02x ", (unsigned char) *cp); fprintf(stderr, "\n"); #endif - if (sendto(socketfd, buf, len, 0, + if (sendto(socketfd, xbuf, len, 0, (struct sockaddr *) &sa, sizeof(sa)) < 0) { bb_perror_msg("send"); len = -1; @@ -292,7 +295,7 @@ static int tftp(const int cmd, const struct hostent *host, switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) { case 1: - len = recvfrom(socketfd, buf, tftp_bufsize, 0, + len = recvfrom(socketfd, rbuf, tftp_bufsize, 0, (struct sockaddr *) &from, &fromlen); if (len < 0) { @@ -334,8 +337,8 @@ static int tftp(const int cmd, const struct hostent *host, /* process received packet */ - opcode = ntohs(*((unsigned short *) buf)); - tmp = ntohs(*((unsigned short *) &buf[2])); + opcode = ntohs(*((unsigned short *) rbuf)); + tmp = ntohs(*((unsigned short *) &rbuf[2])); #if ENABLE_DEBUG_TFTP fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, tmp); @@ -344,9 +347,9 @@ static int tftp(const int cmd, const struct hostent *host, if (opcode == TFTP_ERROR) { const char *msg = NULL; - if (buf[4] != '\0') { - msg = &buf[4]; - buf[tftp_bufsize - 1] = '\0'; + if (rbuf[4] != '\0') { + msg = &rbuf[4]; + rbuf[tftp_bufsize - 1] = '\0'; } else if (tmp < (sizeof(tftp_bb_error_msg) / sizeof(char *))) { @@ -370,7 +373,7 @@ static int tftp(const int cmd, const struct hostent *host, char *res; - res = tftp_option_get(&buf[2], len - 2, OPTION_BLOCKSIZE); + res = tftp_option_get(&rbuf[2], len - 2, OPTION_BLOCKSIZE); if (res) { int blksize = xatoi_u(res); @@ -408,7 +411,7 @@ static int tftp(const int cmd, const struct hostent *host, if (tmp == block_nr) { - len = full_write(localfd, &buf[4], len - 4); + len = full_write(localfd, &rbuf[4], len - 4); if (len < 0) { bb_perror_msg(bb_msg_write_error); @@ -450,7 +453,8 @@ static int tftp(const int cmd, const struct hostent *host, #if ENABLE_FEATURE_CLEAN_UP close(socketfd); - free(buf); + free(xbuf); + free(rbuf); #endif return finished ? EXIT_SUCCESS : EXIT_FAILURE; |