Initial revision

3 files changed, 868 insertions, 0 deletions

diff --git a/contrib/mini-slamd/COPYING b/contrib/mini-slamd/COPYING
new file mode 100644
index 00000000..a43ea212
--- /dev/null
+++ b/contrib/mini-slamd/COPYING
@@ -0,0 +1,339 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+                          675 Mass Ave, Cambridge, MA 02139, USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
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+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
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+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
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+Thus, it is not the intent of this section to claim rights or contest
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+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
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+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
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+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
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+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	Appendix: How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) 19yy  <name of author>
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) 19yy name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.
diff --git a/contrib/mini-slamd/Makefile b/contrib/mini-slamd/Makefile
new file mode 100644
index 00000000..05f1a366
--- /dev/null
+++ b/contrib/mini-slamd/Makefile
@@ -0,0 +1,8 @@
+CC=gcc
+CFLAGS=-Wall -O2
+
+mini-slamd: mini-slamd.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+clean:
+	rm -f mini-slamd
\ No newline at end of file
diff --git a/contrib/mini-slamd/mini-slamd.c b/contrib/mini-slamd/mini-slamd.c
new file mode 100644
index 00000000..7c33e22b
--- /dev/null
+++ b/contrib/mini-slamd/mini-slamd.c
@@ -0,0 +1,521 @@
+/*
+ * mini-slamd
+ * (c) 2002 Eric Biederman
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <netinet/ip.h>
+#include <netinet/in.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+
+/*
+ * To specify the default interface for multicast packets use:
+ * route add -net 224.0.0.0 netmask 240.0.0.0 dev eth1
+ * This server is stupid and does not override the default.
+ */
+
+/* Sever states.
+ *
+ * Waiting for clients.
+ * Sending data to clients.
+ * Pinging clients for data.
+ *
+ */
+#define SLAM_PORT 10000
+#define SLAM_MULTICAST_IP ((239<<24)|(255<<16)|(1<<8)|(1<<0))
+#define SLAM_MULTICAST_PORT 10000
+#define SLAM_MULTICAST_TTL 1
+#define SLAM_MULTICAST_LOOPBACK 1
+#define SLAM_MAX_CLIENTS 10
+
+#define SLAM_PING_TIMEOUT	100 /* ms */
+
+/*** Packets Formats ***
+ * Data Packet:
+ *   transaction
+ *   total bytes
+ *   block size
+ *   packet #
+ *   data
+ *
+ * Status Request Packet
+ *   transaction
+ *   total bytes
+ *   block packets
+ *
+ * Status Packet
+ *   received packets
+ *   requested packets
+ *   received packets
+ *   requested packets
+ *   ...
+ *   received packets
+ *   requested packtes
+ *   0
+ */
+
+#define MAX_HDR (7 + 7 + 7) /* transaction, total size, block size */
+#define MIN_HDR (1 + 1 + 1) /* transaction, total size, block size */
+
+#define MAX_DATA_HDR (MAX_HDR + 7) /* header, packet # */
+#define MIN_DATA_HDR (MAX_HDR + 1) /* header, packet # */
+
+/* ETH_MAX_MTU 1500 - sizeof(iphdr) 20  - sizeof(udphdr) 8 = 1472 */
+#define SLAM_MAX_NACK		(1500 - (20 + 8))
+/* ETH_MAX_MTU 1500 - sizeof(iphdr) 20  - sizeof(udphdr) 8 - MAX_HDR = 1451 */
+#define SLAM_BLOCK_SIZE		(1500 - (20 + 8 + MAX_HDR))
+
+
+/* Define how many debug messages you want 
+ * 1 - sparse but useful
+ * 2 - everything
+ */
+#ifndef DEBUG
+#define DEBUG 0
+#endif
+
+static int slam_encode(
+	unsigned char **ptr, unsigned char *end, unsigned long value)
+{
+	unsigned char *data = *ptr;
+	int bytes;
+	bytes = sizeof(value);
+	while ((bytes > 0) && ((0xff & (value >> ((bytes -1)<<3))) == 0)) {
+		bytes--;
+	}
+	if (bytes <= 0) {
+		bytes = 1;
+	}
+	if (data + bytes >= end) {
+		return -1;
+	}
+	if ((0xe0 & (value >> ((bytes -1)<<3))) == 0) {
+		/* packed together */
+		*data = (bytes << 5) | (value >> ((bytes -1)<<3));
+	} else {
+		bytes++;
+		*data = (bytes << 5);
+	}
+	bytes--;
+	data++;
+	while(bytes) {
+		*(data++) = 0xff & (value >> ((bytes -1)<<3));
+		bytes--;
+	}
+	*ptr = data;
+	return 0;
+}
+
+static unsigned long slam_decode(unsigned char **ptr, unsigned char *end, int *err)
+{
+	unsigned long value;
+	unsigned bytes;
+	if (*ptr >= end) {
+		*err = -1;
+	}
+	bytes = ((**ptr) >> 5) & 7;
+	if ((bytes == 0) || (bytes > sizeof(unsigned long))) {
+		*err = -1;
+		return 0;
+	}
+	if ((*ptr) + bytes >= end) {
+		*err =  -1;
+	}
+	value = (**ptr) & 0x1f;
+	bytes--;
+	(*ptr)++;
+	while(bytes) {
+		value <<= 8;
+		value |= **ptr;
+		(*ptr)++;
+		bytes--;
+	}
+	return value;
+}
+
+
+static struct sockaddr_in client[SLAM_MAX_CLIENTS];
+static int clients;
+
+
+void del_client(struct sockaddr_in *old)
+{
+	int i;
+	for(i = 0; i < clients; i++) {
+		if ((client[i].sin_family == old->sin_family) &&
+			(client[i].sin_addr.s_addr == old->sin_addr.s_addr) &&
+			(client[i].sin_port == old->sin_port)) {
+			memmove(&client[i], &client[i+1],
+				(clients - (i+1))*sizeof(client[0]));
+			clients--;
+		}
+	}
+}
+
+void add_client(struct sockaddr_in *new)
+{
+	del_client(new);
+	if (clients >= SLAM_MAX_CLIENTS)
+		return;
+	memcpy(&client[clients], new, sizeof(*new));
+	clients++;
+}
+
+void push_client(struct sockaddr_in *new)
+{
+	del_client(new);
+	if (clients >= SLAM_MAX_CLIENTS) {
+		clients--;
+	}
+	memmove(&client[1], &client[0], clients*sizeof(*new));
+	memcpy(&client[0], new, sizeof(*new));
+	clients++;
+}
+
+
+void next_client(struct sockaddr_in *next)
+{
+	/* Find the next client we want to ping next */
+	if (!clients) {
+		next->sin_family = AF_UNSPEC;
+		return;
+	}
+	/* Return the first client */
+	memcpy(next, &client[0], sizeof(*next));
+}
+
+int main(int argc, char **argv)
+{
+	char *filename;
+	uint8_t nack_packet[SLAM_MAX_NACK];
+	int nack_len;
+	uint8_t request_packet[MAX_HDR];
+	int request_len;
+	uint8_t data_packet[MAX_DATA_HDR +  SLAM_BLOCK_SIZE];
+	int data_len;
+	uint8_t *ptr, *end;
+	struct sockaddr_in master_client;
+	struct sockaddr_in sa_src;
+	struct sockaddr_in sa_mcast;
+	uint8_t mcast_ttl;
+	uint8_t mcast_loop;
+	int sockfd, filefd;
+	int result;
+	struct pollfd fds[1];
+	int state;
+#define STATE_PINGING      1
+#define STATE_WAITING      2
+#define STATE_RECEIVING    3
+#define STATE_TRANSMITTING 4
+	off_t size;
+	struct stat st;
+	uint64_t transaction;
+	unsigned long packet;
+	unsigned long packet_count;
+	unsigned slam_port, slam_multicast_port;
+	struct in_addr slam_multicast_ip;
+
+	slam_port = SLAM_PORT;
+	slam_multicast_port = SLAM_MULTICAST_PORT;
+	slam_multicast_ip.s_addr = htonl(SLAM_MULTICAST_IP);
+	
+	if (argc != 2) {
+		fprintf(stderr, "Bad argument count\n");
+		fprintf(stderr, "Usage: mini-slamd filename\n");
+		exit(EXIT_FAILURE);
+	}
+	filename = argv[1];
+	filefd = -1;
+	size = 0;
+	transaction = 0;
+
+	/* Setup the udp socket */
+	sockfd = socket(PF_INET, SOCK_DGRAM, 0);
+	if (sockfd < 0) {
+		fprintf(stderr, "Cannot create socket\n");
+		exit(EXIT_FAILURE);
+	}
+	memset(&sa_src, 0, sizeof(sa_src));
+	sa_src.sin_family = AF_INET;
+	sa_src.sin_port = htons(slam_port);
+	sa_src.sin_addr.s_addr = INADDR_ANY;
+
+	result = bind(sockfd, &sa_src, sizeof(sa_src));
+	if (result < 0) { 
+		fprintf(stderr, "Cannot bind socket to port %d\n", 
+			ntohs(sa_src.sin_port));
+		exit(EXIT_FAILURE);
+	}
+
+	/* Setup the multicast transmission address */
+	memset(&sa_mcast, 0, sizeof(sa_mcast));
+	sa_mcast.sin_family = AF_INET;
+	sa_mcast.sin_port = htons(slam_multicast_port);
+	sa_mcast.sin_addr.s_addr = slam_multicast_ip.s_addr;
+	if (!IN_MULTICAST(ntohl(sa_mcast.sin_addr.s_addr))) {
+		fprintf(stderr, "Not a multicast ip\n");
+		exit(EXIT_FAILURE);
+	}
+
+	/* Set the multicast ttl */
+	mcast_ttl = SLAM_MULTICAST_TTL;
+	setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL,
+		&mcast_ttl, sizeof(mcast_ttl));
+
+	/* Set the multicast loopback status */
+	mcast_loop = SLAM_MULTICAST_LOOPBACK;
+	setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &mcast_loop, sizeof(mcast_loop));
+
+
+	state = STATE_WAITING;
+	packet = 0;
+	packet_count = 0;
+	fds[0].fd = sockfd;
+	fds[0].events = POLLIN;
+	fds[0].revents = 0;
+	for(;;) {
+		switch(state) {
+		case STATE_PINGING:
+			state = STATE_WAITING;
+			next_client(&master_client);
+			if (master_client.sin_family == AF_UNSPEC) {
+				break;
+			}
+#if DEBUG
+			printf("Pinging %s:%d\n", 
+				inet_ntoa(master_client.sin_addr),
+				ntohs(master_client.sin_port));
+			fflush(stdout);
+#endif
+
+			/* Prepare the request packet, it is all header */
+			ptr = request_packet;
+			end = &request_packet[sizeof(request_packet) -1];
+			slam_encode(&ptr, end, transaction);
+			slam_encode(&ptr, end, size);
+			slam_encode(&ptr, end, SLAM_BLOCK_SIZE);
+			request_len = ptr - request_packet;
+
+			result = sendto(sockfd, request_packet, request_len, 0,
+				&master_client, sizeof(master_client));
+			/* Forget the client I just asked, when the reply
+			 * comes in we will remember it again.
+			 */
+			del_client(&master_client);
+			break;
+		case STATE_WAITING:
+		{
+			int timeout;
+			int from_len;
+			timeout = -1;
+			if (master_client.sin_family != AF_UNSPEC) {
+				timeout = SLAM_PING_TIMEOUT;
+			}
+			result = poll(fds, sizeof(fds)/sizeof(fds[0]), timeout);
+			if (result == 0) {
+				/* On a timeout try the next client */
+				state = STATE_PINGING;
+				break;
+			}
+			if (result > 0) {
+				from_len = sizeof(master_client);
+				result = recvfrom(sockfd, 
+					nack_packet, 	sizeof(nack_packet), 0,
+					&master_client, &from_len);
+				if (result < 0)
+					break;
+				nack_len = result;
+#if DEBUG
+				printf("Received Nack from %s:%d\n",
+					inet_ntoa(master_client.sin_addr),
+					ntohs(master_client.sin_port));
+				fflush(stdout);
+#endif
+#if DEBUG
+				{
+					ptr = nack_packet;
+					end = ptr + result;
+					packet = 0;
+					result = 0;
+					while(ptr < end) {
+						packet += slam_decode(&ptr, end, &result);
+						if (result < 0) break;
+						packet_count = slam_decode(&ptr, end, &result);
+						if (result < 0) break;
+						printf("%d-%d ",
+							packet, packet + packet_count -1);
+					}
+					printf("\n");
+					fflush(stdout);
+				}
+#endif
+				/* Forget this client temporarily.
+				 * If the packet appears good they will be
+				 * readded.
+				 */
+				del_client(&master_client);
+				ptr = nack_packet;
+				end = ptr + nack_len;
+				result = 0;
+				packet = slam_decode(&ptr, end, &result);
+				if (result < 0)
+					break;
+				packet_count = slam_decode(&ptr, end, &result);
+				if (result < 0)
+					break;
+				/* We appear to have a good packet, keep
+				 * this client.
+				 */
+				push_client(&master_client);
+
+				/* Reopen the file to transmit */
+				if (filefd != -1) {
+					close(filefd);
+				}
+				filefd = open(filename, O_RDONLY);
+				if (filefd < 0) {
+					fprintf(stderr, "Cannot open %s: %s\n",
+						filename, strerror(errno));
+					break;
+				}
+				size = lseek(filefd, 0, SEEK_END);
+				if (size < 0) {
+					fprintf(stderr, "Seek failed on %s: %s\n",
+						filename, strerror(errno));
+					break;
+				}
+				result = fstat(filefd, &st);
+				if (result < 0) {
+					fprintf(stderr, "Stat failed on %s: %s\n",
+						filename, strerror(errno));
+					break;
+				}
+				transaction = st.st_mtime;
+				
+				state = STATE_TRANSMITTING;
+				break;
+			}
+			break;
+		}
+		case STATE_RECEIVING:
+			/* Now clear the queue of received packets */
+		{
+			struct sockaddr_in from;
+			int from_len;
+			uint8_t dummy_packet[SLAM_MAX_NACK];
+			state = STATE_TRANSMITTING;
+			result = poll(fds, sizeof(fds)/sizeof(fds[0]), 0);
+			if (result < 1)
+				break;
+			from_len = sizeof(from);
+			result = recvfrom(sockfd, 
+				dummy_packet, sizeof(dummy_packet), 0,
+				&from, &from_len);
+			if (result <= 0)
+				break;
+#if DEBUG				
+			printf("Received Nack from %s:%d\n",
+				inet_ntoa(from.sin_addr),
+				ntohs(from.sin_port));
+			fflush(stdout);
+#endif
+			/* Receive packets until I don't get any more */
+			state = STATE_RECEIVING;
+			/* Process a  packet */
+			if (dummy_packet[0] == '\0') {
+				/* If the first byte is null it is a disconnect
+				 * packet.  
+				 */
+				del_client(&from);
+			}
+			else {
+				/* Otherwise attempt to add the client. */
+				add_client(&from);
+			}
+			break;
+		}
+		case STATE_TRANSMITTING:
+		{
+			off_t off;
+			off_t offset;
+			ssize_t bytes;
+			uint8_t *ptr2, *end2;
+
+			/* After I transmit a packet check for packets to receive. */
+			state = STATE_RECEIVING;
+
+			/* Find the packet to transmit */
+			offset = packet * SLAM_BLOCK_SIZE;
+
+			/* Seek to the desired packet */
+			off = lseek(filefd, offset, SEEK_SET);
+			if ((off < 0) || (off != offset)) {
+		 		fprintf(stderr, "Seek failed on %s:%s\n",
+					filename, strerror(errno));
+				break;
+			}
+			/* Encode the packet header */
+			ptr2 = data_packet;
+			end2 = data_packet + sizeof(data_packet);
+			slam_encode(&ptr2, end2, transaction);
+			slam_encode(&ptr2, end2, size);
+			slam_encode(&ptr2, end2, SLAM_BLOCK_SIZE);
+			slam_encode(&ptr2, end2, packet);
+			data_len = ptr2 - data_packet;
+			
+			/* Read in the data */
+			bytes = read(filefd, &data_packet[data_len], 
+				SLAM_BLOCK_SIZE);
+			if (bytes <= 0) {
+				fprintf(stderr, "Read failed on %s:%s\n",
+					filename, strerror(errno));
+				break;
+			}
+			data_len += bytes;
+			/* Write out the data */
+			result = sendto(sockfd, data_packet, data_len, 0,
+				&sa_mcast, sizeof(sa_mcast));
+			if (result != data_len) {
+				fprintf(stderr, "Send failed %s\n",
+					strerror(errno));
+				break;
+			}
+#if DEBUG > 1
+			printf("Transmitted: %d\n", packet);
+			fflush(stdout);
+#endif
+			/* Compute the next packet */
+			packet++;
+			packet_count--;
+			if (packet_count == 0) {
+				packet += slam_decode(&ptr, end, &result);
+				if (result >= 0)
+					packet_count = slam_decode(&ptr, end, &result);
+				if (result < 0) {
+					/* When a transmission is done close the file,
+					 * so it may be updated.  And then ping then start
+					 * pinging clients to get the transmission started
+					 * again.
+					 */
+					state = STATE_PINGING;
+					close(filefd);
+					filefd = -1;
+					break;
+				}
+			}
+			break;
+		}
+		}
+	}
+	return EXIT_SUCCESS;
+}