hush/patches/tftp_timeout_multicast.diff

Index: AUTHORS
===================================================================
RCS file: /var/cvs/busybox/AUTHORS,v
retrieving revision 1.40
diff -u -r1.40 AUTHORS
--- a/AUTHORS	9 Oct 2003 21:19:21 -0000	1.40
+++ b/AUTHORS	5 Mar 2004 15:45:47 -0000
@@ -92,6 +92,9 @@
     Original author of BusyBox in 1995, 1996. Some of his code can 
     still be found hiding here and there...
 
+John Powers <jpp@ti.com>
+    Added multicast option (rfc2090) and timeout option (rfc2349) to tftp.
+
 Tim Riker <Tim@Rikers.org>
     bug fixes, member of fan club
 
Index: include/usage.h
===================================================================
RCS file: /var/cvs/busybox/include/usage.h,v
retrieving revision 1.191
diff -u -r1.191 usage.h
--- a/include/usage.h	25 Feb 2004 10:35:55 -0000	1.191
+++ b/include/usage.h	5 Mar 2004 15:45:59 -0000
@@ -2492,6 +2492,21 @@
 #else
   #define USAGE_TFTP_BS(a)
 #endif
+#ifdef CONFIG_FEATURE_TFTP_TIMEOUT
+  #define USAGE_TFTP_TIMEOUT(a) a
+#else
+  #define USAGE_TFTP_TIMEOUT(a)
+#endif
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+  #define USAGE_TFTP_MULTICAST(a) a
+#else
+  #define USAGE_TFTP_MULTICAST(a)
+#endif
+#ifdef CONFIG_FEATURE_TFTP_DEBUG
+  #define USAGE_TFTP_DEBUG(a) a
+#else
+  #define USAGE_TFTP_DEBUG(a)
+#endif
 
 #define tftp_trivial_usage \
 	"[OPTION]... HOST [PORT]"
@@ -2508,6 +2523,16 @@
 	) \
 	USAGE_TFTP_BS( \
 	"\t-b SIZE\tTransfer blocks of SIZE octets.\n" \
+	) \
+	USAGE_TFTP_TIMEOUT( \
+	"\t-T SEC\tClient timeout SEC seconds (default: 5).\n" \
+	"\t-t SEC\tServer timeout SEC seconds\n" \
+	) \
+	USAGE_TFTP_MULTICAST( \
+	"\t-m\tMulticast get file.\n" \
+	) \
+	USAGE_TFTP_DEBUG( \
+	"\t-D\tPrint debug messages.\n" \
 	)
 #define time_trivial_usage \
 	"[OPTION]... COMMAND [ARGS...]"
Index: networking/Config.in
===================================================================
RCS file: /var/cvs/busybox/networking/Config.in,v
retrieving revision 1.27
diff -u -r1.27 Config.in
--- a/networking/Config.in	22 Feb 2004 12:25:47 -0000	1.27
+++ b/networking/Config.in	5 Mar 2004 15:45:59 -0000
@@ -522,6 +522,13 @@
 	  Add support for the GET command within the TFTP client.  This allows
 	  a client to retrieve a file from a TFTP server.
 
+config CONFIG_FEATURE_TFTP_MULTICAST
+	bool "  Enable \"multicast\" option"
+	default n
+	depends on CONFIG_FEATURE_TFTP_GET
+	help
+	  Allow the client to receive multicast file transfers.
+
 config CONFIG_FEATURE_TFTP_PUT
 	bool "  Enable \"put\" command"
 	default y
@@ -531,12 +538,19 @@
 	  a client to transfer a file to a TFTP server.
 
 config CONFIG_FEATURE_TFTP_BLOCKSIZE
-	bool "  Enable \"blocksize\" command"
+	bool "  Enable \"blksize\" option"
 	default n
 	depends on CONFIG_TFTP
 	help
 	  Allow the client to specify the desired block size for transfers.
 
+config CONFIG_FEATURE_TFTP_TIMEOUT
+	bool "  Enable \"timeout\" option"
+	default n
+	depends on CONFIG_TFTP
+	help
+	  Allow the client to negotiate timeout option with server.
+
 config CONFIG_FEATURE_TFTP_DEBUG
 	bool "  Enable debug"
 	default n
Index: networking/tftp.c
===================================================================
RCS file: /var/cvs/busybox/networking/tftp.c,v
retrieving revision 1.25
diff -u -r1.25 tftp.c
--- a/networking/tftp.c	5 Mar 2004 13:04:39 -0000	1.25
+++ b/networking/tftp.c	5 Mar 2004 15:46:00 -0000
@@ -1,11 +1,26 @@
+/* vi: set sw=4 ts=4: */
 /* ------------------------------------------------------------------------- */
 /* tftp.c                                                                    */
+/* Copyright (c) 2003, 2004 Texas Instruments                                */
+/*                                                                           */
+/* This package is free software;  you can redistribute it and/or            */
+/* modify it under the terms of the license found in the file                */
+/* named COPYING that should have accompanied this file.                     */
+/*                                                                           */
+/* THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR             */
+/* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED            */
+/* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.       */
 /*                                                                           */
 /* A simple tftp client for busybox.                                         */
 /* Tries to follow RFC1350.                                                  */
 /* Only "octet" mode supported.                                              */
 /* Optional blocksize negotiation (RFC2347 + RFC2348)                        */
 /*                                                                           */
+/* New features added at Texas Instruments, October 2003                     */
+/* Author: John Powers                                                       */
+/* Multicast option: rfc2090                                                 */
+/* Timeout option: rfc2349                                                   */
+/*                                                                           */
 /* Copyright (C) 2001 Magnus Damm <damm@opensource.se>                       */
 /*                                                                           */
 /* Parts of the code based on:                                               */
@@ -46,8 +61,20 @@
 
 #include "busybox.h"
 
+#if defined(CONFIG_FEATURE_TFTP_BLOCKSIZE) || defined(CONFIG_FEATURE_TFTP_MULTICAST) || defined(CONFIG_FEATURE_TFTP_TIMEOUT)
+  #define TFTP_OPTIONS
+#endif
+
 //#define CONFIG_FEATURE_TFTP_DEBUG
 
+#ifdef CONFIG_FEATURE_TFTP_DEBUG
+	static void printtime(void);
+	#define dprintf(fmt...) if (debug) {printtime(); printf(fmt);}
+	int debug = 0;
+#else
+	#define dprintf(fmt...)
+#endif
+
 #define TFTP_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
 #define TFTP_TIMEOUT 5             /* seconds */
 
@@ -68,12 +95,24 @@
 	"Illegal TFTP operation",
 	"Unknown transfer ID",
 	"File already exists",
-	"No such user"
+	"No such user",
+#ifdef TFTP_OPTIONS
+	"Unsupported option",
+#endif
 };
 
 const int tftp_cmd_get = 1;
 const int tftp_cmd_put = 2;
 
+
+struct tftp_option {
+	int multicast;
+	int blksize;
+	int client_timeout;
+	int server_timeout;
+};
+
+
 #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
 
 static int tftp_blocksize_check(int blocksize, int bufsize)  
@@ -93,16 +132,158 @@
 	return blocksize;
 }
 
+#endif
+
+#ifdef CONFIG_FEATURE_TFTP_TIMEOUT
+
+static int
+tftp_timeout_check(int timeout)
+{
+	/* Check if timeout seconds is valid:
+	 * RFC2349 says between 1 and 255.
+	 */
+
+	if (timeout < 1 || timeout > 255) {
+		bb_error_msg("bad timeout value");
+		return 0;
+	}
+	return timeout;
+}
+
+#endif
+
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+static int
+tftp_multicast_check(const char *opt, char **phost, unsigned short *pport, int *pactive)
+{
+	/* Option string contains comma delimited addr,port,active.
+	 * addr = multicast IP address
+	 * port = port number
+	 * active = 1 if active client
+	 *          0 if passive client
+	 *
+	 * Addr and port will be empty fields when the server notifies a
+	 * passive client that it is now the active client.
+	 *
+	 * The host address string must be freed by the caller. Neither host
+	 * nor port will be set/changed if the input fields are empty.
+	 *
+	 * If any tokenization errors occur in the opt string, the host
+	 * address string is automatically freed.
+	 *
+	 * Return 0 if any tokenization error, 1 if all parameters are good.
+	 */
+
+	char *token = NULL;
+	char *parse_buf = NULL;
+	char *tokenv = NULL;
+	char *host = NULL;
+	int port;
+	int active;
+
+	parse_buf = bb_xstrdup(opt);
+
+	dprintf("multicast option=%s\n", opt);
+
+	/* IP address */
+	if ((token = strtok_r(parse_buf, ",", &tokenv)) == NULL) {
+		dprintf("tftp_multicast_check: cannot parse IP address from %s\n", parse_buf);
+		free(parse_buf);
+		return 0;
+	}
+	if (strlen(token) > 0)
+		*phost = host = bb_xstrdup(token);
+
+	/* Port */
+	if ((token = strtok_r(NULL, ",", &tokenv)) == NULL) {
+		dprintf("tftp_multicast_check: cannot parse port number from %s\n", tokenv);
+		goto token_error;
+	}
+	if (strlen(token) > 0) {
+		port = atoi(token);
+		if (port < 0 || port > 0xFFFF) {
+			dprintf("tftp_multicast_check: bad port number (%d)\n", port);
+			goto token_error;
+		}
+		*pport = htons(port);
+	}
+
+	/* Active/passive */
+	if ((token = strtok_r(NULL, ",", &tokenv)) == NULL) {
+		dprintf("tftp_multicast_check: cannot parse active/passive from %s\n", tokenv);
+		goto token_error;
+	}
+	active = atoi(token);
+	if (active != 0 && active != 1) {
+		dprintf("tftp_multicast_check: bad active/passive flag (%d)\n", active);
+		goto token_error;
+	}
+	*pactive = active;
+
+	free(parse_buf);
+	return 1;
+
+token_error:
+	free(parse_buf);
+	if (host != NULL)
+		free(host);
+	*phost = NULL;
+	return 0;
+
+}
+
+#define VECTOR_QUANTUM_WIDTH 8
+#define VECTOR_QUANTUM_ALL_ONES ((1<<VECTOR_QUANTUM_WIDTH)-1)
+
+static void inline
+bit_set(int bit, unsigned char *vector)
+{
+	int offset = bit / VECTOR_QUANTUM_WIDTH;
+	int mask = 1 << (bit % VECTOR_QUANTUM_WIDTH);
+	vector[offset] |= mask;
+}
+
+static int inline
+bit_isset(int bit, const unsigned char *vector)
+{
+	int offset = bit / VECTOR_QUANTUM_WIDTH;
+	int mask = 1 << (bit % VECTOR_QUANTUM_WIDTH);
+	return vector[offset] & mask ? 1 : 0;
+}
+
+static int inline
+bit_lmz(const unsigned char *vector)
+{
+	/* Return number of left-most zero in bit vector */
+	const unsigned char *vp = vector;
+	int i;
+	unsigned char velem;
+
+	while (*vp == VECTOR_QUANTUM_ALL_ONES)
+		vp++;
+	velem = *vp;
+	for (i = 0; i < VECTOR_QUANTUM_WIDTH; i++) {
+		if ((velem & (1 << i)) == 0)
+			break;
+	}
+	dprintf("bit_lmz: block=%d\n", (vp - vector)*VECTOR_QUANTUM_WIDTH + i);
+	return (vp - vector)*VECTOR_QUANTUM_WIDTH + i;
+}
+
+#endif
+
+
+
+#ifdef TFTP_OPTIONS
+
 static char *tftp_option_get(char *buf, int len, char *option)  
 {
-        int opt_val = 0;
+	int opt_val = 0;
 	int opt_found = 0;
 	int k;
-  
-	while (len > 0) {
 
+	while (len > 0) {
 	        /* Make sure the options are terminated correctly */
-
 	        for (k = 0; k < len; k++) {
 		        if (buf[k] == '\0') {
 			        break;
@@ -117,9 +298,8 @@
 			if (strcasecmp(buf, option) == 0) {
 			        opt_found = 1;
 			}
-		}      
-		else {
-		        if (opt_found) {
+		} else {
+			if (opt_found) {
 				return buf;
 			}
 		}
@@ -138,7 +318,8 @@
 #endif
 
 static inline int tftp(const int cmd, const struct hostent *host,
-	const char *remotefile, int localfd, const unsigned short port, int tftp_bufsize)
+	const char *remotefile, int localfd, const unsigned short port,
+	struct tftp_option *option)
 {
 	const int cmd_get = cmd & tftp_cmd_get;
 	const int cmd_put = cmd & tftp_cmd_put;
@@ -155,18 +336,29 @@
 	int len;
 	int opcode = 0;
 	int finished = 0;
-	int timeout = bb_tftp_num_retries;
+	int retry = bb_tftp_num_retries;
 	unsigned short block_nr = 1;
 
-#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
-	int want_option_ack = 0;
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+	struct hostent *mchost;
+	struct sockaddr_in mcsa;
+	char *mchostname;
+	unsigned short mcport;
+	unsigned char *mcblockmap = NULL;
+	int master_client = 1;
+	int mcfd = -1;
+	int mcmaxblock = 0x10000;
+	int ack_oack = 0;
+#else
+	#define master_client 1
+    #define ack_oack 0
 #endif
 
 	/* 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);
+	char *buf=xmalloc(option->blksize + 4);
 
-	tftp_bufsize += 4;
+	int tftp_bufsize = option->blksize + 4;
 
 	if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
 		bb_perror_msg("socket");
@@ -183,15 +375,21 @@
 	memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr,
 		   sizeof(sa.sin_addr));
 
-	/* build opcode */
-
-	if (cmd_get) {
-		opcode = TFTP_RRQ;
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+	if (option->multicast) {
+		const int bmsize = 0x10000 / VECTOR_QUANTUM_WIDTH;
+		if ((mcfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
+			bb_perror_msg("multicast socket");
+			return EXIT_FAILURE;
+		}
+		mcblockmap = xmalloc(bmsize+1);
+		memset(mcblockmap, 0, bmsize+1);
 	}
+#endif
 
-	if (cmd_put) {
-		opcode = TFTP_WRQ;
-	}
+	/* build opcode */
+
+	opcode = cmd_get ? TFTP_RRQ : TFTP_WRQ;
 
 	while (1) {
 
@@ -203,7 +401,7 @@
 
 		cp += 2;
 
-		/* add filename and mode */
+		/* First packet of file transfer includes file name, mode, and options */
 
 		if ((cmd_get && (opcode == TFTP_RRQ)) ||
 			(cmd_put && (opcode == TFTP_WRQ))) {
@@ -223,7 +421,7 @@
 			}
 
 			if (too_long || ((&buf[tftp_bufsize - 1] - cp) < 6)) {
-				bb_error_msg("too long remote-filename");
+				bb_error_msg("too long: remote filename");
 				break;
 			}
 
@@ -238,8 +436,8 @@
 
 			if (len != TFTP_BLOCKSIZE_DEFAULT) {
 
-			        if ((&buf[tftp_bufsize - 1] - cp) < 15) {
-				        bb_error_msg("too long remote-filename");
+				if ((&buf[tftp_bufsize - 1] - cp) < 15) {
+					bb_error_msg("buffer too small for blksize option");
 					break;
 				}
 
@@ -249,16 +447,65 @@
 				cp += 8;
 
 				cp += snprintf(cp, 6, "%d", len) + 1;
+			}
+#endif
+
+
+
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+
+			if (option->multicast) {
+				if ((&buf[tftp_bufsize - 1] - cp) < 12) {
+					bb_error_msg("buffer too small for multicast option");
+					break;
+				}
+
+				/* add "multicast" option */
 
-				want_option_ack = 1;
+				memcpy(cp, "multicast\0", 11);
+				cp += 11;
+
+				option->multicast = 0;	/* turn back on when server accepts option */
+				ack_oack = 1;	/* acknowledge OACK */
 			}
+
 #endif
+
+#ifdef CONFIG_FEATURE_TFTP_TIMEOUT
+
+			if (option->server_timeout != TFTP_TIMEOUT) {
+				if ((&buf[tftp_bufsize - 1] - cp) < 12) {
+					bb_error_msg("buffer too small for timeout option");
+					break;
+				}
+
+				/* add "timeout" option */
+
+				memcpy(cp, "timeout", 8);
+				cp += 8;
+
+				cp += snprintf(cp, 4, "%d", option->server_timeout) + 1;
+			}
+#endif
+
 		}
 
 		/* add ack and data */
 
-		if ((cmd_get && (opcode == TFTP_ACK)) ||
-			(cmd_put && (opcode == TFTP_DATA))) {
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+		else if (option->multicast && opcode == TFTP_ACK) {
+			if (master_client || ack_oack) {
+				int blocknum = bit_lmz(mcblockmap);
+				*((unsigned short *) cp) = htons(blocknum);
+				cp += 2;
+				if (blocknum >= mcmaxblock)
+					finished = 1;
+				dprintf("ack block %d/%d %s\n", blocknum, mcmaxblock, finished? "finished": "");
+			}
+		}
+#endif
+		else if ((cmd_get && opcode == TFTP_ACK) ||
+			(cmd_put && opcode == TFTP_DATA)) {
 
 			*((unsigned short *) cp) = htons(block_nr);
 
@@ -275,7 +522,7 @@
 				}
 
 				if (len != (tftp_bufsize - 4)) {
-					finished++;
+					finished = 1;
 				}
 
 				cp += len;
@@ -283,82 +530,119 @@
 		}
 
 
-		/* send packet */
+		/* send packet and receive reply */
 
 
-		timeout = bb_tftp_num_retries;  /* re-initialize */
+		retry = bb_tftp_num_retries;  /* re-initialize */
 		do {
-
+			int selectrc;
 			len = cp - buf;
 
-#ifdef CONFIG_FEATURE_TFTP_DEBUG
-			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;
-			}
-
+			/* send packet */
+			if ((len > 2) && (! option->multicast || master_client || ack_oack)) {
 
-			if (finished && (opcode == TFTP_ACK)) {
-				break;
+#ifdef CONFIG_FEATURE_TFTP_DEBUG
+				dprintf("sending %u bytes\n", len);
+				for (cp = buf; cp < &buf[len]; cp++)
+					if (debug)
+						printf("%02x ", *(unsigned char *)cp);
+				if (debug)
+					printf("\n");
+#endif
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+				ack_oack = 0;
+#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 */
+			/* receive reply packet */
 
 			memset(&from, 0, sizeof(from));
 			fromlen = sizeof(from);
 
-			tv.tv_sec = TFTP_TIMEOUT;
+			tv.tv_sec = option->client_timeout;
 			tv.tv_usec = 0;
 
 			FD_ZERO(&rfds);
 			FD_SET(socketfd, &rfds);
+			dprintf("set to receive from socketfd (%d)\n", socketfd);
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+			if (option->multicast) {
+				FD_SET(mcfd, &rfds);
+				dprintf("set to receive from mcfd (%d)\n", mcfd);
+			}
+#endif
 
-			switch (select(FD_SETSIZE, &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;
+			dprintf("select\n");
+			selectrc = select(FD_SETSIZE, &rfds, NULL, NULL, &tv);
+			if (selectrc > 0) {
+				/* A packet was received */
+				if (FD_ISSET(socketfd, &rfds)) { /* Unicast packet */
+					dprintf("from socketfd\n");
+					len = recvfrom(socketfd, buf, tftp_bufsize, 0, (struct sockaddr *) &from, &fromlen);
+
+					if (len < 0) {
+						bb_perror_msg("recvfrom");
+					} else {
+						if (sa.sin_port == port) {
+							sa.sin_port = from.sin_port;
+						}
+						if (sa.sin_port == from.sin_port) {
+							retry = 0;
+						} else {
+							/* bad packet */
+							/* discard the packet - treat as timeout */
+							retry = bb_tftp_num_retries;
+							bb_error_msg("timeout");
+						}
+					}
 				}
 
-				timeout = 0;
-
-				if (sa.sin_port == port) {
-					sa.sin_port = from.sin_port;
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+				else if (option->multicast && FD_ISSET(mcfd, &rfds)) { /* Multicast packet */
+					dprintf("from mcfd\n");
+					len = recvfrom(mcfd, buf, tftp_bufsize, 0, (struct sockaddr *) &from, &fromlen);
+					if (len < 0) {
+						bb_perror_msg("multicast recvfrom");
+					} else {
+						if (mcsa.sin_port == mcport) {
+							mcsa.sin_port = from.sin_port;
+						}
+						if (mcsa.sin_port == from.sin_port) {
+							retry = 0;
+						} else {
+							retry = bb_tftp_num_retries;
+							bb_error_msg("multicast timeout");
+						}
+					}
 				}
-				if (sa.sin_port == from.sin_port) {
-					break;
-				}
-
-				/* fall-through for bad packets! */
-				/* discard the packet - treat as timeout */
-				timeout = bb_tftp_num_retries;
+#endif
 
-			case 0:
+			} else if (selectrc == 0) {
+				/* Time out */
+				dprintf("timeout\n");
 				bb_error_msg("timeout");
 
-				timeout--;
-				if (timeout == 0) {
+				retry--;
+				if (retry == 0) {
 					len = -1;
 					bb_error_msg("last timeout");
 				}
-				break;
-
-			default:
+			} else {
+				/* Error condition */
+				dprintf("error\n");
 				bb_perror_msg("select");
 				len = -1;
 			}
 
-		} while (timeout && (len >= 0));
+		} while (retry && len >= 0);
 
 		if ((finished) || (len < 0)) {
 			break;
@@ -370,9 +654,8 @@
 		opcode = ntohs(*((unsigned short *) buf));
 		tmp = ntohs(*((unsigned short *) &buf[2]));
 
-#ifdef CONFIG_FEATURE_TFTP_DEBUG
-		fprintf(stderr, "received %d bytes: %04x %04x\n", len, opcode, tmp);
-#endif
+		dprintf("received %d bytes: %04x %04x\n", len, opcode, tmp);
+		dprintf("master_client=%d\n", master_client);
 
 		if (opcode == TFTP_ERROR) {
 			char *msg = NULL;
@@ -393,55 +676,116 @@
 			break;
 		}
 
-#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
-		if (want_option_ack) {
+#ifdef TFTP_OPTIONS
 
-			 want_option_ack = 0;
+		if (opcode == TFTP_OACK) {
 
-		         if (opcode == TFTP_OACK) {
+			/* server seems to support options */
 
-			         /* server seems to support options */
+			char *res;
+			
+			block_nr = 0;		/* acknowledge option packet with block number 0 */
+			opcode = cmd_put ? TFTP_DATA : TFTP_ACK;
 
-			         char *res;
 
-				 res = tftp_option_get(&buf[2], len-2, 
-						       "blksize");
+#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
+			res = tftp_option_get(&buf[2], len-2, "blksize");
 
-				 if (res) {
-				         int blksize = atoi(res);
-			     
-					 if (tftp_blocksize_check(blksize,
-							   tftp_bufsize - 4)) {
+			if (res) {
+				int blksize = atoi(res);
 
-					         if (cmd_put) {
-				                         opcode = TFTP_DATA;
-						 }
-						 else {
-				                         opcode = TFTP_ACK;
-						 }
-#ifdef CONFIG_FEATURE_TFTP_DEBUG
-						 fprintf(stderr, "using blksize %u\n", blksize);
+				if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) {
+					dprintf("using blksize %d\n", blksize);
+					tftp_bufsize = blksize + 4;
+					free(buf);
+					buf = xmalloc(tftp_bufsize);
+				} else {
+					bb_error_msg("bad blksize %d", blksize);
+					break;
+				}
+			}
 #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;
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+			res = tftp_option_get(&buf[2], len-2, "multicast");
+
+			if (res) {
+				ack_oack = 1;
+				if (tftp_multicast_check(res, &mchostname, &mcport, &master_client)) {
+					struct ip_mreq mreq;
+					struct in_addr mcaddr;
+
+					dprintf("using multicast\n");
+
+					mchost = xgethostbyname(mchostname);
+					if (mchost) {
+						memcpy(&mcaddr, mchost->h_addr, mchost->h_length);
+						if (! IN_MULTICAST(ntohl(mcaddr.s_addr))) {
+							bb_error_msg("bad multicast address: %s", mchostname);
+							break;
+						}
+					} else {
+						bb_error_msg("bad multicast address: %s", mchostname);
+						break;
+					}
+
+					memset(&mcsa, 0, sizeof(mcsa));
+					mcsa.sin_family = AF_INET;
+					mcsa.sin_addr.s_addr = htonl(INADDR_ANY);
+					mcsa.sin_port = mcport;
+
+					bind(mcfd, (struct sockaddr *)&mcsa, sizeof(mcsa));
+
+					mreq.imr_multiaddr.s_addr = mcaddr.s_addr;
+					mreq.imr_interface.s_addr = htonl(INADDR_ANY);
+
+					if (setsockopt(mcfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
+					{
+						bb_error_msg("setsockopt");
+						break;
+					}
+
+					option->multicast = 1;
+				} else {
+					bb_error_msg("bad multicast option value: %s", res);
+					break;
+				}
+			}
+#endif
+
 		}
+		else
 #endif
 
 		if (cmd_get && (opcode == TFTP_DATA)) {
 
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+			if (option->multicast) {
+				int bn = tmp - 1;
+				/* Do I need this block? */
+				if (! bit_isset(bn, mcblockmap)) {
+					lseek(localfd, bn*(tftp_bufsize-4), SEEK_SET);
+					len = write(localfd, &buf[4], len-4);
+					if (len < 0) {
+						bb_perror_msg("write");
+						break;
+					}
+					bit_set(bn, mcblockmap);
+					if (len != (tftp_bufsize-4)) {
+						mcmaxblock = tmp;
+						dprintf("mcmaxblock=%d, (len(%d) != tftp_bufsize-4(%d))\n", mcmaxblock, len, tftp_bufsize-4);
+					}
+					opcode = TFTP_ACK;
+				}
+				/* Do not acknowledge block if I already have a copy of the block. A situation can arise when the server
+				 * and client timeout nearly simultaneously. The server retransmits the block at the same time the client
+				 * re-requests the block. From then on out, each block is transmitted twice--not a good use of bandwidth.
+				 */
+			}
+			else
+#endif
+
 			if (tmp == block_nr) {
 			    
 				len = write(localfd, &buf[4], len - 4);
@@ -452,15 +796,14 @@
 				}
 
 				if (len != (tftp_bufsize - 4)) {
-					finished++;
+					finished = 1;
 				}
 
 				opcode = TFTP_ACK;
-				continue;
 			}
 		}
 
-		if (cmd_put && (opcode == TFTP_ACK)) {
+		else if (cmd_put && opcode == TFTP_ACK) {
 
 			if (tmp == (unsigned short)(block_nr - 1)) {
 				if (finished) {
@@ -468,15 +811,19 @@
 				}
 
 				opcode = TFTP_DATA;
-				continue;
 			}
 		}
 	}
 
 #ifdef CONFIG_FEATURE_CLEAN_UP
 	close(socketfd);
+	free(buf);
+
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+	if (mcblockmap != NULL)
+		free(mcblockmap);
+#endif
 
-        free(buf);
 #endif
 
 	return finished ? EXIT_SUCCESS : EXIT_FAILURE;
@@ -487,13 +834,18 @@
 	struct hostent *host = NULL;
 	char *localfile = NULL;
 	char *remotefile = NULL;
-	int port;
+	unsigned short port;
 	int cmd = 0;
 	int fd = -1;
 	int flags = 0;
 	int opt;
 	int result;
-	int blocksize = TFTP_BLOCKSIZE_DEFAULT;
+	struct tftp_option option = {
+		.multicast		= 0,
+		.blksize		= TFTP_BLOCKSIZE_DEFAULT,
+		.client_timeout	= TFTP_TIMEOUT,
+		.server_timeout	= TFTP_TIMEOUT,
+	};
 
 	/* figure out what to pass to getopt */
 
@@ -515,13 +867,45 @@
 #define PUT 
 #endif
 
-	while ((opt = getopt(argc, argv, BS GET PUT "l:r:")) != -1) {
+#ifdef CONFIG_FEATURE_TFTP_TIMEOUT
+#define TO "T:t:"
+#else
+#define TO
+#endif
+
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+#define MC "m"
+#else
+#define MC
+#endif
+
+#ifdef CONFIG_FEATURE_TFTP_DEBUG
+#define DB "D"
+#else
+#define DB
+#endif
+
+	while ((opt = getopt(argc, argv, BS GET PUT TO MC DB "l:r:")) != -1) {
 		switch (opt) {
 #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
 		case 'b':
-			blocksize = atoi(optarg);
-			if (!tftp_blocksize_check(blocksize, 0)) {
-                                return EXIT_FAILURE;
+			option.blksize = atoi(optarg);
+			if (!tftp_blocksize_check(option.blksize, 0)) {
+				return EXIT_FAILURE;
+			}
+			break;
+#endif
+#ifdef CONFIG_FEATURE_TFTP_TIMEOUT
+		case 'T':
+			option.client_timeout = atoi(optarg);
+			if (!tftp_timeout_check(option.client_timeout)) {
+				return EXIT_FAILURE;
+			}
+			break;
+		case 't':
+			option.server_timeout = atoi(optarg);
+			if (!tftp_timeout_check(option.server_timeout)) {
+				return EXIT_FAILURE;
 			}
 			break;
 #endif
@@ -537,18 +921,34 @@
 			flags = O_RDONLY;
 			break;
 #endif
+#ifdef CONFIG_FEATURE_TFTP_MULTICAST
+		case 'm':
+			option.multicast = 1;	/* receive multicast file */
+			break;
+#endif
+#ifdef CONFIG_FEATURE_TFTP_DEBUG
+		case 'D':
+			debug = 1;
+			break;
+#endif
 		case 'l': 
 			localfile = bb_xstrdup(optarg);
 			break;
 		case 'r':
 			remotefile = bb_xstrdup(optarg);
 			break;
+		default:
+			bb_show_usage();
 		}
 	}
 
 	if ((cmd == 0) || (optind == argc)) {
 		bb_show_usage();
 	}
+	if (cmd == tftp_cmd_put && option.multicast) {
+		fprintf(stderr, "Multicast (-m) invalid option with put (-p) command\n");
+		exit(EXIT_FAILURE);
+	}
 	if(localfile && strcmp(localfile, "-") == 0) {
 	    fd = fileno((cmd==tftp_cmd_get)? stdout : stdin);
 	}
@@ -566,14 +966,12 @@
 	host = xgethostbyname(argv[optind]);
 	port = bb_lookup_port(argv[optind + 1], "udp", 69);
 
-#ifdef CONFIG_FEATURE_TFTP_DEBUG
-	fprintf(stderr, "using server \"%s\", remotefile \"%s\", "
+	dprintf("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);
+	result = tftp(cmd, host, remotefile, fd, port, &option);
 
 #ifdef CONFIG_FEATURE_CLEAN_UP
 	if (!(fd == fileno(stdout) || fd == fileno(stdin))) {
@@ -582,3 +980,18 @@
 #endif
 	return(result);
 }
+
+
+#ifdef CONFIG_FEATURE_TFTP_DEBUG
+
+#include <sys/time.h>
+
+static void
+printtime(void)
+{
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	printf("%11lu.%06lu ", tv.tv_sec, tv.tv_usec);
+}
+
+#endif