--- busybox-1.10.1/networking/tftp.c	
+++ busybox-1.10.1/networking/tftp.c	
@@ -39,7 +39,7 @@
 #define TFTP_ERROR 5
 #define TFTP_OACK  6
 
-/* error codes sent over network (we use only 0, 3 and 8) */
+/* 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
@@ -121,9 +121,8 @@
 	return blksize;
 }
 
-static char *tftp_get_blksize(char *buf, int len)
+static char *tftp_get_option(const char *option, char *buf, int len)
 {
-#define option "blksize"
 	int opt_val = 0;
 	int opt_found = 0;
 	int k;
@@ -155,7 +154,6 @@
 	}
 
 	return NULL;
-#undef option
 }
 
 #endif
@@ -165,6 +163,7 @@
 		len_and_sockaddr *peer_lsa,
 		const char *local_file,
 		USE_TFTP(const char *remote_file,)
+		USE_FEATURE_TFTP_BLOCKSIZE(void *tsize,)
 		int blksize)
 {
 #if !ENABLE_TFTP
@@ -243,9 +242,9 @@
 		if (NOT_LONE_DASH(local_file))
 			local_fd = xopen(local_file, open_mode);
 	} else {
-		local_fd = open_or_warn(local_file, open_mode);
+		local_fd = open(local_file, open_mode);
 		if (local_fd < 0) {
-			/*error_pkt_reason = ERR_NOFILE/ERR_ACCESS?*/
+			error_pkt_reason = ERR_NOFILE;
 			strcpy(error_pkt_str, "can't open file");
 			goto send_err_pkt;
 		}
@@ -253,7 +252,7 @@
 
 	if (!ENABLE_TFTP || our_lsa) {
 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
-		if (blksize != TFTP_BLKSIZE_DEFAULT) {
+		if (blksize != TFTP_BLKSIZE_DEFAULT || tsize) {
 			/* 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),
@@ -313,10 +312,20 @@
 
 #if ENABLE_FEATURE_TFTP_BLOCKSIZE
  add_blksize_opt:
-		/* add "blksize", <nul>, blksize, <nul> */
-		strcpy(cp, "blksize");
-		cp += sizeof("blksize");
-		cp += snprintf(cp, 6, "%d", blksize) + 1;
+		if (tsize) {
+			struct stat st;
+			/* add "tsize", <nul>, size, <nul> */
+			strcpy(cp, "tsize");
+			cp += sizeof("tsize");
+			fstat(local_fd,&st);
+			cp += snprintf(cp, 10, "%u", (int) st.st_size) + 1;
+		}
+		if (blksize != TFTP_BLKSIZE_DEFAULT) {
+			/* add "blksize", <nul>, blksize, <nul> */
+			strcpy(cp, "blksize");
+			cp += sizeof("blksize");
+			cp += snprintf(cp, 6, "%d", blksize) + 1;
+		}
 #endif
 		/* First packet is built, so skip packet generation */
 		goto send_pkt;
@@ -450,7 +459,7 @@
 				/* server seems to support options */
 				char *res;
 
-				res = tftp_get_blksize(&rbuf[2], len - 2);
+				res = tftp_get_option("blksize", &rbuf[2], len - 2);
 				if (res) {
 					blksize = tftp_blksize_check(res, blksize);
 					if (blksize < 0) {
@@ -596,6 +605,7 @@
 	result = tftp_protocol(
 			NULL /* our_lsa*/, peer_lsa,
 			local_file, remote_file,
+			USE_FEATURE_TFTP_BLOCKSIZE(NULL,)
 			blksize);
 
 	if (result != EXIT_SUCCESS && NOT_LONE_DASH(local_file) && CMD_GET(opt)) {
@@ -631,6 +641,7 @@
 	const char *error_msg;
 	int opt, result, opcode;
 	int blksize = TFTP_BLKSIZE_DEFAULT;
+	USE_FEATURE_TFTP_BLOCKSIZE(char *tsize = NULL;)
 
 	INIT_G();
 
@@ -676,7 +687,7 @@
 		char *opt_str = mode + sizeof("octet");
 		int opt_len = block_buf + result - opt_str;
 		if (opt_len > 0) {
-			res = tftp_get_blksize(opt_str, opt_len);
+			res = tftp_get_option("blksize", opt_str, opt_len);
 			if (res) {
 				blksize = tftp_blksize_check(res, 65564);
 				if (blksize < 0) {
@@ -685,6 +696,7 @@
 					goto do_proto;
 				}
 			}
+			tsize = tftp_get_option("tsize", opt_str, opt_len);
 		}
 	}
 #endif
@@ -710,6 +722,7 @@
 	result = tftp_protocol(
 		our_lsa, peer_lsa,
 		local_file, USE_TFTP(NULL /*remote_file*/,)
+		USE_FEATURE_TFTP_BLOCKSIZE(tsize,)
 		blksize
 	);