Added Magnus Damm's tftp applet to Busybox.

8 files changed, 931 insertions, 0 deletions

diff --git a/Config.h b/Config.h
index 6c849a21f..263da98d5 100644
--- a/Config.h
+++ b/Config.h
@@ -104,6 +104,7 @@
 //#define BB_TEE
 //#define BB_TEST
 //#define BB_TELNET
+#define BB_TFTP
 #define BB_TOUCH
 //#define BB_TR
 #define BB_TRUE_FALSE
@@ -312,6 +313,10 @@
 // Support for the -A -B and -C context flags in grep
 //#define BB_FEATURE_GREP_CONTEXT
 //
+// Tell tftp what commands that should be supported.
+#define BB_FEATURE_TFTP_PUT
+#define BB_FEATURE_TFTP_GET
+//
 // End of Features List
 //
 //
diff --git a/applets.h b/applets.h
index dbb234963..36817fef7 100644
--- a/applets.h
+++ b/applets.h
@@ -356,6 +356,9 @@
 #ifdef BB_TEST
 	APPLET(test, test_main, _BB_DIR_USR_BIN)
 #endif
+#ifdef BB_TFTP
+	APPLET(tftp, tftp_main, _BB_DIR_USR_BIN)
+#endif
 #ifdef BB_TOUCH
 	APPLET(touch, touch_main, _BB_DIR_BIN)
 #endif
diff --git a/applets/usage.h b/applets/usage.h
index efc943f68..db7963043 100644
--- a/applets/usage.h
+++ b/applets/usage.h
@@ -994,6 +994,30 @@
 	"Checks file types and compares values returning an exit\n" \
 	"code determined by the value of EXPRESSION."
 
+#ifdef BB_FEATURE_TFTP_GET
+  #define USAGE_TFTP_GET(a) a
+#else
+  #define USAGE_TFTP_GET(a)
+#endif
+#ifdef BB_FEATURE_TFTP_PUT
+  #define USAGE_TFTP_PUT(a) a
+#else
+  #define USAGE_TFTP_PUT(a)
+#endif
+
+#define tftp_trivial_usage \
+	"command SOURCE DEST"
+#define tftp_full_usage \
+	"Transfers a file from/to a tftp server using \"octet\" mode.\n\n" \
+	"Commands:\n" \
+        USAGE_TFTP_GET(	\
+        "\tget\tGet file from server SOURCE and store to local DEST.\n" \
+        ) \
+        USAGE_TFTP_PUT(	\
+	"\tput\tPut local file SOURCE to server DEST.\n" \
+	) \
+	"\nWhen nameing a server, use the syntax \"server:file\"."
+
 #define touch_trivial_usage \
 	"[-c] file [file ...]"
 #define touch_full_usage \
diff --git a/include/applets.h b/include/applets.h
index dbb234963..36817fef7 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -356,6 +356,9 @@
 #ifdef BB_TEST
 	APPLET(test, test_main, _BB_DIR_USR_BIN)
 #endif
+#ifdef BB_TFTP
+	APPLET(tftp, tftp_main, _BB_DIR_USR_BIN)
+#endif
 #ifdef BB_TOUCH
 	APPLET(touch, touch_main, _BB_DIR_BIN)
 #endif
diff --git a/include/usage.h b/include/usage.h
index efc943f68..db7963043 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -994,6 +994,30 @@
 	"Checks file types and compares values returning an exit\n" \
 	"code determined by the value of EXPRESSION."
 
+#ifdef BB_FEATURE_TFTP_GET
+  #define USAGE_TFTP_GET(a) a
+#else
+  #define USAGE_TFTP_GET(a)
+#endif
+#ifdef BB_FEATURE_TFTP_PUT
+  #define USAGE_TFTP_PUT(a) a
+#else
+  #define USAGE_TFTP_PUT(a)
+#endif
+
+#define tftp_trivial_usage \
+	"command SOURCE DEST"
+#define tftp_full_usage \
+	"Transfers a file from/to a tftp server using \"octet\" mode.\n\n" \
+	"Commands:\n" \
+        USAGE_TFTP_GET(	\
+        "\tget\tGet file from server SOURCE and store to local DEST.\n" \
+        ) \
+        USAGE_TFTP_PUT(	\
+	"\tput\tPut local file SOURCE to server DEST.\n" \
+	) \
+	"\nWhen nameing a server, use the syntax \"server:file\"."
+
 #define touch_trivial_usage \
 	"[-c] file [file ...]"
 #define touch_full_usage \
diff --git a/networking/tftp.c b/networking/tftp.c
new file mode 100644
index 000000000..f56d6562e
--- /dev/null
+++ b/networking/tftp.c
@@ -0,0 +1,424 @@
+/* ------------------------------------------------------------------------- */
+/* tftp.c                                                                    */
+/*                                                                           */
+/* A simple tftp client for busybox.                                         */
+/* Tries to follow RFC1350.                                                  */
+/* Only "octet" mode and 512-byte data blocks are supported.                 */
+/*                                                                           */
+/* Copyright (C) 2001 Magnus Damm <damm@opensource.se>                       */
+/*                                                                           */
+/* Parts of the code based on:                                               */
+/*                                                                           */
+/* atftp:  Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca>   */
+/*                        and Remi Lefebvre <remi@debian.org>                */
+/*                                                                           */
+/* utftp:  Copyright (C) 1999 Uwe Ohse <uwe@ohse.de>                         */
+/*                                                                           */
+/* This program is free software; you can redistribute it and/or modify      */
+/* it under the terms of the GNU General Public License as published by      */
+/* the Free Software Foundation; either version 2 of the License, or         */
+/* (at your option) any later version.                                       */
+/*                                                                           */
+/* This program is distributed in the hope that it will be useful,           */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of            */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU          */
+/* General Public License for more details.                                  */
+/*                                                                           */
+/* You should have received a copy of the GNU General Public License         */
+/* along with this program; if not, write to the Free Software               */
+/* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA   */
+/*                                                                           */
+/* ------------------------------------------------------------------------- */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "busybox.h"
+
+//#define BB_FEATURE_TFTP_DEBUG
+
+/* we don't need #ifdefs with these constants and optimization... */
+
+#ifdef BB_FEATURE_TFTP_GET
+#define BB_TFTP_GET (1 << 0)
+#else
+#define BB_TFTP_GET 0
+#endif
+
+#ifdef BB_FEATURE_TFTP_PUT
+#define BB_TFTP_PUT (1 << 1)
+#else
+#define BB_TFTP_PUT 0
+#endif
+
+#ifdef BB_FEATURE_TFTP_DEBUG
+#define BB_TFTP_DEBUG 1
+#else
+#define BB_TFTP_DEBUG 0
+#endif
+
+#define BB_TFTP_NO_RETRIES 5
+#define BB_TFTP_TIMEOUT    5	/* seconds */
+
+#define	RRQ	1			/* read request */
+#define	WRQ	2			/* write request */
+#define	DATA	3		/* data packet */
+#define	ACK	4			/* acknowledgement */
+#define	ERROR	5		/* error code */
+
+#define BUFSIZE (512+4)
+
+static const char *tftp_error_msg[] = {
+	"Undefined error",
+	"File not found",
+	"Access violation",
+	"Disk full or allocation error",
+	"Illegal TFTP operation",
+	"Unknown transfer ID",
+	"File already exists",
+	"No such user"
+};
+
+static inline int tftp(int cmd, struct hostent *host,
+					   char *serverfile, int localfd, int port)
+{
+	struct sockaddr_in sa;
+	int socketfd;
+	struct timeval tv;
+	fd_set rfds;
+	struct sockaddr_in from;
+	socklen_t fromlen;
+	char *cp;
+	unsigned short tmp;
+	int len, opcode, finished;
+	int timeout, block_nr;
+
+	RESERVE_BB_BUFFER(buf, BUFSIZE);
+
+	opcode = finished = timeout = 0;
+	block_nr = 1;
+
+	if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
+		perror_msg("socket");
+		return 1;
+	}
+
+	len = sizeof(sa);
+
+	memset(&sa, 0, len);
+	bind(socketfd, &sa, len);
+
+	sa.sin_family = host->h_addrtype;
+	sa.sin_port = htons(port);
+	memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr,
+		   sizeof(sa.sin_addr));
+
+	/* build opcode */
+
+	if (cmd & BB_TFTP_GET) {
+		opcode = RRQ;
+	}
+
+	if (cmd & BB_TFTP_PUT) {
+		opcode = WRQ;
+	}
+
+	while (1) {
+
+
+		/* build packet of type "opcode" */
+
+
+		cp = buf;
+
+		*((unsigned short *) cp) = htons(opcode);
+
+		cp += 2;
+
+		/* add filename and mode */
+
+		if ((BB_TFTP_GET && (opcode == RRQ)) ||
+			(BB_TFTP_PUT && (opcode == WRQ))) {
+
+			while (cp != &buf[BUFSIZE - 1]) {
+				if ((*cp = *serverfile++) == '\0')
+					break;
+				cp++;
+			}
+
+			if ((*cp != '\0') || (&buf[BUFSIZE - 1] - cp) < 7) {
+				error_msg("too long server-filename.\n");
+				break;
+			}
+
+			memcpy(cp + 1, "octet", 6);
+			cp += 7;
+		}
+
+		/* add ack and data */
+
+		if ((BB_TFTP_GET && (opcode == ACK)) ||
+			(BB_TFTP_PUT && (opcode == DATA))) {
+
+			*((unsigned short *) cp) = htons(block_nr);
+
+			cp += 2;
+
+			block_nr++;
+
+			if (BB_TFTP_PUT && (opcode == DATA)) {
+				len = read(localfd, cp, BUFSIZE - 4);
+
+				if (len < 0) {
+					perror_msg("read");
+					break;
+				}
+
+				if (len != (BUFSIZE - 4)) {
+					finished++;
+				}
+
+				cp += len;
+			} else if (finished) {
+				break;
+			}
+		}
+
+
+		/* send packet */
+
+
+		do {
+
+			len = cp - buf;
+
+			if (BB_TFTP_DEBUG) {
+				printf("sending %u bytes\n", len);
+
+				for (cp = buf; cp < &buf[len]; cp++)
+					printf("%02x ", *cp);
+				printf("\n");
+			}
+
+			if (sendto(socketfd, buf, len, 0,
+					   (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+				perror_msg("send()");
+				len = -1;
+				break;
+			}
+
+
+			/* receive packet */
+
+
+			memset(&from, 0, sizeof(from));
+			fromlen = sizeof(from);
+
+			tv.tv_sec = BB_TFTP_TIMEOUT;
+			tv.tv_usec = 0;
+
+			FD_ZERO(&rfds);
+			FD_SET(socketfd, &rfds);
+
+			switch (select(FD_SETSIZE, &rfds, NULL, NULL, &tv)) {
+			case 1:
+				len = recvfrom(socketfd, buf,
+							   BUFSIZE, 0,
+							   (struct sockaddr *) &from, &fromlen);
+
+				if (len < 0) {
+					perror_msg("recvfrom");
+					break;
+				}
+
+				timeout = 0;
+
+				if (sa.sin_port == htons(port)) {
+					sa.sin_port = from.sin_port;
+					break;
+				}
+
+				if (sa.sin_port == from.sin_port) {
+					break;
+				}
+
+				/* fall-through for bad packets! */
+				/* discard the packet - treat as timeout */
+
+			case 0:
+				error_msg("timeout.\n");
+
+				if (!timeout) {
+					timeout = BB_TFTP_NO_RETRIES;
+				} else {
+					timeout--;
+				}
+
+				if (!timeout) {
+					len = -1;
+					error_msg("last timeout!\n");
+				}
+				break;
+
+			default:
+				perror_msg("select");
+				len = -1;
+			}
+
+		} while (timeout && (len >= 0));
+
+		if (len < 0) {
+			break;
+		}
+
+		/* process received packet */
+
+
+		opcode = ntohs(*((unsigned short *) buf));
+		tmp = ntohs(*((unsigned short *) &buf[2]));
+
+		if (BB_TFTP_DEBUG) {
+			printf("received %d bytes: %04x %04x\n", len, opcode, tmp);
+		}
+
+		if (BB_TFTP_GET && (opcode == DATA)) {
+
+			if (tmp == block_nr) {
+				len = write(localfd, &buf[4], len - 4);
+
+				if (len < 0) {
+					perror_msg("write");
+					break;
+				}
+
+				if (len != (BUFSIZE - 4)) {
+					finished++;
+				}
+
+				opcode = ACK;
+				continue;
+			}
+		}
+
+		if (BB_TFTP_PUT && (opcode == ACK)) {
+
+			if (tmp == (block_nr - 1)) {
+				if (finished) {
+					break;
+				}
+
+				opcode = DATA;
+				continue;
+			}
+		}
+
+		if (opcode == ERROR) {
+			char *msg = NULL;
+
+			if (buf[4] != '\0') {
+				msg = &buf[4];
+				buf[BUFSIZE - 1] = '\0';
+			} else if (tmp < (sizeof(tftp_error_msg) / sizeof(char *))) {
+				msg = (char *) tftp_error_msg[tmp];
+			}
+
+			if (msg) {
+				error_msg("server says: %s.\n", msg);
+			}
+
+			break;
+		}
+	}
+
+	close(socketfd);
+
+	if (finished) {
+		return 0;
+	}
+
+	return 1;
+}
+
+int tftp_main(int argc, char **argv)
+{
+	char *cp, *s;
+	char *serverstr;
+	struct hostent *host;
+	char *serverfile;
+	char *localfile;
+	int cmd, flags, fd, bad;
+
+	host = (void *) serverstr = serverfile = localfile = NULL;
+	flags = cmd = 0;
+	bad = 1;
+
+	if (argc > 3) {
+		if (BB_TFTP_GET && (strcmp(argv[1], "get") == 0)) {
+			cmd = BB_TFTP_GET;
+			flags = O_WRONLY | O_CREAT;
+			serverstr = argv[2];
+			localfile = argv[3];
+		}
+
+		if (BB_TFTP_PUT && (strcmp(argv[1], "put") == 0)) {
+			cmd = BB_TFTP_PUT;
+			flags = O_RDONLY;
+			localfile = argv[2];
+			serverstr = argv[3];
+		}
+
+	}
+
+	if (!(cmd & (BB_TFTP_GET | BB_TFTP_PUT))) {
+		show_usage();
+	}
+
+	for (cp = serverstr; *cp != '\0'; cp++)
+		if (*cp == ':')
+			break;
+
+	if (*cp == ':') {
+
+		serverfile = cp + 1;
+
+		if ((s = strdup(serverstr))) {
+			s[cp - serverstr] = '\0';
+
+			if ((host = gethostbyname(s))) {
+				bad = 0;
+			}
+		}
+
+		free(s);
+	}
+	if (bad) {
+		perror_msg_and_die("bad \"server:file\" combination");
+	}
+
+	if (BB_TFTP_DEBUG) {
+		printf("using server \"%s\", serverfile \"%s\","
+			   "localfile \"%s\".\n",
+			   inet_ntoa(*((struct in_addr *) host->h_addr)),
+			   serverfile, localfile);
+	}
+
+	if ((fd = open(localfile, flags, 0644)) < 0) {
+		perror_msg_and_die("local file");
+	}
+
+	flags = tftp(cmd, host, serverfile, fd, 69);
+
+	close(fd);
+
+	return flags;
+}
diff --git a/tftp.c b/tftp.c
new file mode 100644
index 000000000..f56d6562e
--- /dev/null
+++ b/tftp.c
@@ -0,0 +1,424 @@
+/* ------------------------------------------------------------------------- */
+/* tftp.c                                                                    */
+/*                                                                           */
+/* A simple tftp client for busybox.                                         */
+/* Tries to follow RFC1350.                                                  */
+/* Only "octet" mode and 512-byte data blocks are supported.                 */
+/*                                                                           */
+/* Copyright (C) 2001 Magnus Damm <damm@opensource.se>                       */
+/*                                                                           */
+/* Parts of the code based on:                                               */
+/*                                                                           */
+/* atftp:  Copyright (C) 2000 Jean-Pierre Lefebvre <helix@step.polymtl.ca>   */
+/*                        and Remi Lefebvre <remi@debian.org>                */
+/*                                                                           */
+/* utftp:  Copyright (C) 1999 Uwe Ohse <uwe@ohse.de>                         */
+/*                                                                           */
+/* This program is free software; you can redistribute it and/or modify      */
+/* it under the terms of the GNU General Public License as published by      */
+/* the Free Software Foundation; either version 2 of the License, or         */
+/* (at your option) any later version.                                       */
+/*                                                                           */
+/* This program is distributed in the hope that it will be useful,           */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of            */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU          */
+/* General Public License for more details.                                  */
+/*                                                                           */
+/* You should have received a copy of the GNU General Public License         */
+/* along with this program; if not, write to the Free Software               */
+/* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA   */
+/*                                                                           */
+/* ------------------------------------------------------------------------- */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "busybox.h"
+
+//#define BB_FEATURE_TFTP_DEBUG
+
+/* we don't need #ifdefs with these constants and optimization... */
+
+#ifdef BB_FEATURE_TFTP_GET
+#define BB_TFTP_GET (1 << 0)
+#else
+#define BB_TFTP_GET 0
+#endif
+
+#ifdef BB_FEATURE_TFTP_PUT
+#define BB_TFTP_PUT (1 << 1)
+#else
+#define BB_TFTP_PUT 0
+#endif
+
+#ifdef BB_FEATURE_TFTP_DEBUG
+#define BB_TFTP_DEBUG 1
+#else
+#define BB_TFTP_DEBUG 0
+#endif
+
+#define BB_TFTP_NO_RETRIES 5
+#define BB_TFTP_TIMEOUT    5	/* seconds */
+
+#define	RRQ	1			/* read request */
+#define	WRQ	2			/* write request */
+#define	DATA	3		/* data packet */
+#define	ACK	4			/* acknowledgement */
+#define	ERROR	5		/* error code */
+
+#define BUFSIZE (512+4)
+
+static const char *tftp_error_msg[] = {
+	"Undefined error",
+	"File not found",
+	"Access violation",
+	"Disk full or allocation error",
+	"Illegal TFTP operation",
+	"Unknown transfer ID",
+	"File already exists",
+	"No such user"
+};
+
+static inline int tftp(int cmd, struct hostent *host,
+					   char *serverfile, int localfd, int port)
+{
+	struct sockaddr_in sa;
+	int socketfd;
+	struct timeval tv;
+	fd_set rfds;
+	struct sockaddr_in from;
+	socklen_t fromlen;
+	char *cp;
+	unsigned short tmp;
+	int len, opcode, finished;
+	int timeout, block_nr;
+
+	RESERVE_BB_BUFFER(buf, BUFSIZE);
+
+	opcode = finished = timeout = 0;
+	block_nr = 1;
+
+	if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
+		perror_msg("socket");
+		return 1;
+	}
+
+	len = sizeof(sa);
+
+	memset(&sa, 0, len);
+	bind(socketfd, &sa, len);
+
+	sa.sin_family = host->h_addrtype;
+	sa.sin_port = htons(port);
+	memcpy(&sa.sin_addr, (struct in_addr *) host->h_addr,
+		   sizeof(sa.sin_addr));
+
+	/* build opcode */
+
+	if (cmd & BB_TFTP_GET) {
+		opcode = RRQ;
+	}
+
+	if (cmd & BB_TFTP_PUT) {
+		opcode = WRQ;
+	}
+
+	while (1) {
+
+
+		/* build packet of type "opcode" */
+
+
+		cp = buf;
+
+		*((unsigned short *) cp) = htons(opcode);
+
+		cp += 2;
+
+		/* add filename and mode */
+
+		if ((BB_TFTP_GET && (opcode == RRQ)) ||
+			(BB_TFTP_PUT && (opcode == WRQ))) {
+
+			while (cp != &buf[BUFSIZE - 1]) {
+				if ((*cp = *serverfile++) == '\0')
+					break;
+				cp++;
+			}
+
+			if ((*cp != '\0') || (&buf[BUFSIZE - 1] - cp) < 7) {
+				error_msg("too long server-filename.\n");
+				break;
+			}
+
+			memcpy(cp + 1, "octet", 6);
+			cp += 7;
+		}
+
+		/* add ack and data */
+
+		if ((BB_TFTP_GET && (opcode == ACK)) ||
+			(BB_TFTP_PUT && (opcode == DATA))) {
+
+			*((unsigned short *) cp) = htons(block_nr);
+
+			cp += 2;
+
+			block_nr++;
+
+			if (BB_TFTP_PUT && (opcode == DATA)) {
+				len = read(localfd, cp, BUFSIZE - 4);
+
+				if (len < 0) {
+					perror_msg("read");
+					break;
+				}
+
+				if (len != (BUFSIZE - 4)) {
+					finished++;
+				}
+
+				cp += len;
+			} else if (finished) {
+				break;
+			}
+		}
+
+
+		/* send packet */
+
+
+		do {
+
+			len = cp - buf;
+
+			if (BB_TFTP_DEBUG) {
+				printf("sending %u bytes\n", len);
+
+				for (cp = buf; cp < &buf[len]; cp++)
+					printf("%02x ", *cp);
+				printf("\n");
+			}
+
+			if (sendto(socketfd, buf, len, 0,
+					   (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+				perror_msg("send()");
+				len = -1;
+				break;
+			}
+
+
+			/* receive packet */
+
+
+			memset(&from, 0, sizeof(from));
+			fromlen = sizeof(from);
+
+			tv.tv_sec = BB_TFTP_TIMEOUT;
+			tv.tv_usec = 0;
+
+			FD_ZERO(&rfds);
+			FD_SET(socketfd, &rfds);
+
+			switch (select(FD_SETSIZE, &rfds, NULL, NULL, &tv)) {
+			case 1:
+				len = recvfrom(socketfd, buf,
+							   BUFSIZE, 0,
+							   (struct sockaddr *) &from, &fromlen);
+
+				if (len < 0) {
+					perror_msg("recvfrom");
+					break;
+				}
+
+				timeout = 0;
+
+				if (sa.sin_port == htons(port)) {
+					sa.sin_port = from.sin_port;
+					break;
+				}
+
+				if (sa.sin_port == from.sin_port) {
+					break;
+				}
+
+				/* fall-through for bad packets! */
+				/* discard the packet - treat as timeout */
+
+			case 0:
+				error_msg("timeout.\n");
+
+				if (!timeout) {
+					timeout = BB_TFTP_NO_RETRIES;
+				} else {
+					timeout--;
+				}
+
+				if (!timeout) {
+					len = -1;
+					error_msg("last timeout!\n");
+				}
+				break;
+
+			default:
+				perror_msg("select");
+				len = -1;
+			}
+
+		} while (timeout && (len >= 0));
+
+		if (len < 0) {
+			break;
+		}
+
+		/* process received packet */
+
+
+		opcode = ntohs(*((unsigned short *) buf));
+		tmp = ntohs(*((unsigned short *) &buf[2]));
+
+		if (BB_TFTP_DEBUG) {
+			printf("received %d bytes: %04x %04x\n", len, opcode, tmp);
+		}
+
+		if (BB_TFTP_GET && (opcode == DATA)) {
+
+			if (tmp == block_nr) {
+				len = write(localfd, &buf[4], len - 4);
+
+				if (len < 0) {
+					perror_msg("write");
+					break;
+				}
+
+				if (len != (BUFSIZE - 4)) {
+					finished++;
+				}
+
+				opcode = ACK;
+				continue;
+			}
+		}
+
+		if (BB_TFTP_PUT && (opcode == ACK)) {
+
+			if (tmp == (block_nr - 1)) {
+				if (finished) {
+					break;
+				}
+
+				opcode = DATA;
+				continue;
+			}
+		}
+
+		if (opcode == ERROR) {
+			char *msg = NULL;
+
+			if (buf[4] != '\0') {
+				msg = &buf[4];
+				buf[BUFSIZE - 1] = '\0';
+			} else if (tmp < (sizeof(tftp_error_msg) / sizeof(char *))) {
+				msg = (char *) tftp_error_msg[tmp];
+			}
+
+			if (msg) {
+				error_msg("server says: %s.\n", msg);
+			}
+
+			break;
+		}
+	}
+
+	close(socketfd);
+
+	if (finished) {
+		return 0;
+	}
+
+	return 1;
+}
+
+int tftp_main(int argc, char **argv)
+{
+	char *cp, *s;
+	char *serverstr;
+	struct hostent *host;
+	char *serverfile;
+	char *localfile;
+	int cmd, flags, fd, bad;
+
+	host = (void *) serverstr = serverfile = localfile = NULL;
+	flags = cmd = 0;
+	bad = 1;
+
+	if (argc > 3) {
+		if (BB_TFTP_GET && (strcmp(argv[1], "get") == 0)) {
+			cmd = BB_TFTP_GET;
+			flags = O_WRONLY | O_CREAT;
+			serverstr = argv[2];
+			localfile = argv[3];
+		}
+
+		if (BB_TFTP_PUT && (strcmp(argv[1], "put") == 0)) {
+			cmd = BB_TFTP_PUT;
+			flags = O_RDONLY;
+			localfile = argv[2];
+			serverstr = argv[3];
+		}
+
+	}
+
+	if (!(cmd & (BB_TFTP_GET | BB_TFTP_PUT))) {
+		show_usage();
+	}
+
+	for (cp = serverstr; *cp != '\0'; cp++)
+		if (*cp == ':')
+			break;
+
+	if (*cp == ':') {
+
+		serverfile = cp + 1;
+
+		if ((s = strdup(serverstr))) {
+			s[cp - serverstr] = '\0';
+
+			if ((host = gethostbyname(s))) {
+				bad = 0;
+			}
+		}
+
+		free(s);
+	}
+	if (bad) {
+		perror_msg_and_die("bad \"server:file\" combination");
+	}
+
+	if (BB_TFTP_DEBUG) {
+		printf("using server \"%s\", serverfile \"%s\","
+			   "localfile \"%s\".\n",
+			   inet_ntoa(*((struct in_addr *) host->h_addr)),
+			   serverfile, localfile);
+	}
+
+	if ((fd = open(localfile, flags, 0644)) < 0) {
+		perror_msg_and_die("local file");
+	}
+
+	flags = tftp(cmd, host, serverfile, fd, 69);
+
+	close(fd);
+
+	return flags;
+}
diff --git a/usage.h b/usage.h
index efc943f68..db7963043 100644
--- a/usage.h
+++ b/usage.h
@@ -994,6 +994,30 @@
 	"Checks file types and compares values returning an exit\n" \
 	"code determined by the value of EXPRESSION."
 
+#ifdef BB_FEATURE_TFTP_GET
+  #define USAGE_TFTP_GET(a) a
+#else
+  #define USAGE_TFTP_GET(a)
+#endif
+#ifdef BB_FEATURE_TFTP_PUT
+  #define USAGE_TFTP_PUT(a) a
+#else
+  #define USAGE_TFTP_PUT(a)
+#endif
+
+#define tftp_trivial_usage \
+	"command SOURCE DEST"
+#define tftp_full_usage \
+	"Transfers a file from/to a tftp server using \"octet\" mode.\n\n" \
+	"Commands:\n" \
+        USAGE_TFTP_GET(	\
+        "\tget\tGet file from server SOURCE and store to local DEST.\n" \
+        ) \
+        USAGE_TFTP_PUT(	\
+	"\tput\tPut local file SOURCE to server DEST.\n" \
+	) \
+	"\nWhen nameing a server, use the syntax \"server:file\"."
+
 #define touch_trivial_usage \
 	"[-c] file [file ...]"
 #define touch_full_usage \