Refactor, keep tracing on stderr, corrections for iovec size and dup dgram handling.

5 files changed, 205 insertions, 126 deletions

diff --git a/mcastseed/src/dgrambuf.c b/mcastseed/src/dgrambuf.c
index b07ba1f..b19b698 100644
--- a/mcastseed/src/dgrambuf.c
+++ b/mcastseed/src/dgrambuf.c
@@ -12,6 +12,7 @@
 #include <stdio.h> /* perror() */
 #include <string.h> /* memset() */
 #include <sys/uio.h> /* writev() */
+#include <sys/param.h> /* MIN() */
 
 struct uint_pair {
 	unsigned int index;
@@ -19,17 +20,19 @@ struct uint_pair {
 };
 
 struct dgrambuf_t {
-	size_t dgram_count;
+	size_t dgram_slots;
+	size_t dgram_free_count;
 	size_t dgram_max_size;
 	size_t dgram_header_size;
 
-	struct iovec *recv_iovecs;
-	struct iovec *write_iovecs;
+	size_t iovec_slots;
+	struct iovec *iov_recv;
+	struct iovec *iov_write;
 	struct mmsghdr *msgs;
 
-	unsigned int win_base;
-	unsigned int *dgram_seq_numbers; /* Stores the decoded datagram sequence number for each dgram slot of buf */
+	unsigned int dgram_seq_base;
 	unsigned int *dgram_len;
+	unsigned int *dgram_seq_numbers; /* Stores the decoded datagram sequence number for each dgram slot of buf */
 	struct uint_pair *dgram_ordered_seq_numbers;
 
 	void *buf;
@@ -44,33 +47,40 @@ void dgrambuf_set_validate_func(dgrambuf_t dbuf, unsigned int (*func)(unsigned i
 	dbuf->validate_func = func;
 }
 
+size_t dgrambuf_free_count(const dgrambuf_t dbuf) {
+	return dbuf->dgram_free_count;
+}
+
 int dgrambuf_recvmmsg(dgrambuf_t dbuf, int sockfd) {
   void *dgram_base;
 	size_t vlen, i, dgram_index;
 	int recv_msg_count, res;
 	unsigned int seq, dgram_len;
 
-	if ( !dbuf->validate_func ) {
+	/* Buffer is full, can't receive */
+	if ( dbuf->dgram_free_count == 0 ) {
 		return -1;
 	}
 
+	/* Validate function is mandatory */
+	if ( !dbuf->validate_func ) {
+		return -2;
+	}
+
 	/* Initialize recvmmsg() syscall arguments */
-	for (i=0, vlen=0; i < dbuf->dgram_count; i++) {
+	for (i=0, vlen=0; i < dbuf->dgram_slots; i++) {
 		if ( dbuf->dgram_seq_numbers[i] == 0 ) {
-			dbuf->recv_iovecs[vlen].iov_base = dbuf->buf + i*dbuf->dgram_max_size;
-			dbuf->recv_iovecs[vlen].iov_len = dbuf->dgram_max_size;
+			dbuf->iov_recv[vlen].iov_base = dbuf->buf + i*dbuf->dgram_max_size;
+			dbuf->iov_recv[vlen].iov_len = dbuf->dgram_max_size;
 			memset(dbuf->msgs + vlen, 0, sizeof(struct mmsghdr));
-			dbuf->msgs[vlen].msg_hdr.msg_iov = dbuf->recv_iovecs + vlen;
+			dbuf->msgs[vlen].msg_hdr.msg_iov = dbuf->iov_recv + vlen;
 			dbuf->msgs[vlen].msg_hdr.msg_iovlen = 1;
 			vlen++;
+			if ( vlen == dbuf->iovec_slots )
+				break;
 		}
 	}
 
-	/* Buffer is full, can't receive */
-	if ( vlen==0 ) {
-		return -2;
-	}
-
 	/* Do the syscall */
 	recv_msg_count = recvmmsg(sockfd, dbuf->msgs, vlen, MSG_WAITFORONE, NULL);
 	if (recv_msg_count < 0) {
@@ -81,28 +91,29 @@ int dgrambuf_recvmmsg(dgrambuf_t dbuf, int sockfd) {
 	/* Check all received messages */
 	res = 1;
 	for (i=0; i<recv_msg_count; i++) {
-		dgram_base = dbuf->recv_iovecs[i].iov_base;
+		dgram_base = dbuf->iov_recv[i].iov_base;
 		dgram_index = (dgram_base - dbuf->buf) / dbuf->dgram_max_size;
 		dgram_len = dbuf->msgs[i].msg_len;
 		seq = dbuf->validate_func(dgram_len, dgram_base);
 		// TODO better feedback
 		if ( seq == 0 ) {
-			printf("#%zi invalid (%u)\n", i, seq);
+			fprintf(stderr, "dgrambuf_recvmmsg(): #%zi invalid (%u)\n", i, seq);
 			dbuf->dgram_seq_numbers[dgram_index] = 0;
 		} else if ( seq == -1 ) {
-			printf("#%zi end\n", i);
+			fprintf(stderr, "dgrambuf_recvmmsg(): #%zi end\n", i);
 			dbuf->dgram_seq_numbers[dgram_index] = 0;
 			res = 0;
-		} else if ( seq < dbuf->win_base ) {
-			printf("#%zi past (%u)\n", i, seq);
+		} else if ( seq < dbuf->dgram_seq_base ) {
+			fprintf(stderr, "dgrambuf_recvmmsg(): #%zi past (%u)\n", i, seq);
 			dbuf->dgram_seq_numbers[dgram_index] = 0;
-		} else if ( seq >= dbuf->win_base + dbuf->dgram_count ) {
-			printf("#%zi future (%u)\n", i, seq);
+		} else if ( seq >= dbuf->dgram_seq_base + dbuf->dgram_slots ) {
+			fprintf(stderr, "dgrambuf_recvmmsg(): #%zi future (%u)\n", i, seq);
 			dbuf->dgram_seq_numbers[dgram_index] = 0;
 		} else {
-			printf("#%zi valid (%u)\n", i, seq);
+			//fprintf(stderr, "dgrambuf_recvmmsg(): #%zi valid (%u)\n", i, seq);
 			dbuf->dgram_seq_numbers[dgram_index] = seq;
 			dbuf->dgram_len[dgram_index] = dgram_len;
+			dbuf->dgram_free_count--;
 		}
 	}
 
@@ -114,40 +125,52 @@ ssize_t dgrambuf_write(dgrambuf_t dbuf, int fd) {
 	unsigned int curr_seq, prev_seq, dgram_len;
 	ssize_t nwrite, total;
 
+	/* Buffer is empty, nothing to write */
+	if ( dbuf->dgram_free_count == dbuf->dgram_slots ) {
+		return -1;
+	}
+
 	/* Initialize dgram_ordered_seq_numbers from dgram_seq_numbers */
-	for (i=0; i < dbuf->dgram_count; i++) {
+	for (i=0; i < dbuf->dgram_slots; i++) {
 		dbuf->dgram_ordered_seq_numbers[i].index = i;
 		dbuf->dgram_ordered_seq_numbers[i].value = dbuf->dgram_seq_numbers[i];
 	}
 	/* Inplace sorting of dgram_ordered_seq_numbers */
-	qsort(dbuf->dgram_ordered_seq_numbers, dbuf->dgram_count, sizeof(struct uint_pair), _compare_uint_pair);
+	qsort(dbuf->dgram_ordered_seq_numbers, dbuf->dgram_slots, sizeof(struct uint_pair), _compare_uint_pair);
 	
 	/* Initialize iovecs for writev, take dgram payloads following the sequence numbers */
-	for (prev_seq=0, vlen=0, total=0, i=0; i< dbuf->dgram_count; i++) {
+	prev_seq=0, vlen=0, total=0;
+	for (i=dbuf->dgram_free_count; i < dbuf->dgram_slots; i++) {
 		curr_seq = dbuf->dgram_ordered_seq_numbers[i].value;
 
 		/* Skip empty dgram slot */
-		if ( curr_seq == 0 )
+		if ( curr_seq == 0 ) {
+			fprintf(stderr, "Oops : found empty slot (i==%zi)\n", i);
+			continue;
+		}
+
+		/* Skip if current dgram is a dup of the previous */
+		if ( curr_seq == prev_seq ) {
+			dgram_index = dbuf->dgram_ordered_seq_numbers[i].index;
+			/* Mark slot as empty */
+			dbuf->dgram_seq_numbers[dgram_index] = 0;
+			dbuf->dgram_free_count++;
 			continue;
+		}
 
 		/* Skip dgram comming from the past */
-		if ( curr_seq < dbuf->win_base ) {
+		if ( curr_seq < dbuf->dgram_seq_base ) {
 			fprintf(stderr, "Oops : found dgram from past in buffer (%u)\n", curr_seq);
 			continue;
 		}
 
-		/* Break if first dgram to write is not in buffer at all */
-		if ( ( vlen==0 ) && (curr_seq != dbuf->win_base) ) {
-			fprintf(stderr, "Oops : nothing to write, missing %u seq\n", dbuf->win_base);
+		/* Stop if first dgram to write is not in buffer at all */
+		if ( ( vlen==0 ) && (curr_seq != dbuf->dgram_seq_base) ) {
+			fprintf(stderr, "Oops : nothing to write, missing %u seq\n", dbuf->dgram_seq_base);
 			break;
 		}
 
-		/* Skip if next dgram is a dup */
-		if ( ( vlen > 0 ) && (curr_seq == prev_seq) ) {
-			continue;
-		}
-
-		/* Break if next seq dgram is missing */
+		/* Stop if current seq dgram is missing */
 		if ( ( vlen > 0 ) && (curr_seq > prev_seq+1 ) ) {
 			break;
 		}
@@ -156,87 +179,91 @@ ssize_t dgrambuf_write(dgrambuf_t dbuf, int fd) {
 		dgram_index = dbuf->dgram_ordered_seq_numbers[i].index;
 		dgram_len = dbuf->dgram_len[dgram_index] - dbuf->dgram_header_size;
 
-		dbuf->write_iovecs[vlen].iov_len = dgram_len; /* Setup iovecs */
-		dbuf->write_iovecs[vlen].iov_base = dbuf->buf + dgram_index*dbuf->dgram_max_size + dbuf->dgram_header_size;
-		dbuf->dgram_seq_numbers[dgram_index] = 0; /* Mark dgram slots about to be written out as reusable */
+		dbuf->iov_write[vlen].iov_len = dgram_len; /* Setup iovecs */
+		dbuf->iov_write[vlen].iov_base = dbuf->buf + dgram_index*dbuf->dgram_max_size + dbuf->dgram_header_size;
+		dbuf->dgram_seq_numbers[dgram_index] = 0; /* Mark dgram slots about to be written out as empty for next read */
 
 		total += dgram_len; /* Update counters */
-		vlen++;
-		dbuf->win_base = curr_seq;
+		dbuf->dgram_free_count++;
+		dbuf->dgram_seq_base = curr_seq + 1;
 		prev_seq = curr_seq;
+		vlen++;
+		/* Don't plan to write more than iovec_slots slots */
+		if ( vlen == dbuf->iovec_slots )
+			break;
 	}
 
-	/* If nothing valid to write out */
+	/* Nothing valid to write out (but buffer not empty, missing the next dgram) */
 	if ( vlen == 0 ) {
 		return -1;
 	}
 
-	nwrite = writev(fd, dbuf->write_iovecs, vlen);
+	nwrite = writev(fd, dbuf->iov_write, vlen);
 	if ( nwrite < 0 ) {
 		perror("writev()");
-		return nwrite;
-	}
-
-	if ( nwrite != total ) {
+	} else if ( nwrite != total ) {
+		//FIXME : everything break if there because all non writed data will be overwritted at next read
+		// Make a loop here could make dgrambuf_writev() unbounded in run time
 		fprintf(stderr, "writev() short\n");
-		return nwrite;
 	}
 
 	return nwrite;
 }
 
-dgrambuf_t dgrambuf_new(size_t dgram_count, size_t dgram_max_size, size_t dgram_header_size) {
+dgrambuf_t dgrambuf_new(size_t dgram_slots, size_t dgram_max_size, size_t dgram_header_size, size_t iovec_slots) {
 
 	dgrambuf_t dbuf = calloc(1, sizeof(struct dgrambuf_t));
 	if (!dbuf) goto fail0;
 
-	dbuf->dgram_count = dgram_count;
+	dbuf->dgram_slots = dgram_slots;
+	dbuf->dgram_free_count = dgram_slots;
 	dbuf->dgram_max_size = dgram_max_size;
 	dbuf->dgram_header_size = dgram_header_size;
+	dbuf->iovec_slots = MIN(iovec_slots,dgram_slots);
 
-	dbuf->recv_iovecs = calloc(dgram_count, sizeof(struct iovec));
-	if (!dbuf->recv_iovecs) goto fail1;
+	dbuf->iov_recv = calloc(iovec_slots, sizeof(struct iovec));
+	if (!dbuf->iov_recv) goto fail1;
 
-	dbuf->write_iovecs = calloc(dgram_count, sizeof(struct iovec));
-	if (!dbuf->write_iovecs) goto fail2;
+	dbuf->iov_write = calloc(iovec_slots, sizeof(struct iovec));
+	if (!dbuf->iov_write) goto fail2;
 
-	dbuf->msgs = calloc(dgram_count, sizeof(struct mmsghdr));
+	dbuf->msgs = calloc(iovec_slots, sizeof(struct mmsghdr));
 	if (!dbuf->msgs) goto fail3;
 
-	dbuf->win_base = 1;
-	dbuf->dgram_seq_numbers = calloc(dgram_count, sizeof(unsigned int));
-	if (!dbuf->dgram_seq_numbers) goto fail4;
+	dbuf->dgram_seq_base = 1;
+	dbuf->dgram_len = calloc(dgram_slots, sizeof(unsigned int));
+	if (!dbuf->dgram_len) goto fail4;
 
-	dbuf->dgram_len = calloc(dgram_count, sizeof(ssize_t));
-	if (!dbuf->dgram_len) goto fail5;
+	dbuf->dgram_seq_numbers = calloc(dgram_slots, sizeof(unsigned int));
+	if (!dbuf->dgram_seq_numbers) goto fail5;
 
-	dbuf->dgram_ordered_seq_numbers = calloc(dgram_count, sizeof(struct uint_pair));
+	dbuf->dgram_ordered_seq_numbers = calloc(dgram_slots, sizeof(struct uint_pair));
 	if (!dbuf->dgram_ordered_seq_numbers) goto fail6;
 
-	dbuf->buf = calloc(dgram_count, dgram_max_size);
+	dbuf->buf = calloc(dgram_slots, dgram_max_size);
 	if (!dbuf->buf) goto fail7;
 
 	return dbuf;
 
 fail7:  free(dbuf->dgram_ordered_seq_numbers);
-fail6:	free(dbuf->dgram_len);
-fail5:	free(dbuf->dgram_seq_numbers);
+fail6:	free(dbuf->dgram_seq_numbers);
+fail5:	free(dbuf->dgram_len);
 fail4:	free(dbuf->msgs);
-fail3:	free(dbuf->write_iovecs);
-fail2:	free(dbuf->recv_iovecs);
+fail3:	free(dbuf->iov_write);
+fail2:	free(dbuf->iov_recv);
 fail1:	free(dbuf);
-fail0:	return 0;
+fail0:	return NULL;
 }
 
 void dgrambuf_free(dgrambuf_t *dbuf) {
 	if (dbuf && *dbuf) {
 		free((*dbuf)->buf);
 		free((*dbuf)->dgram_ordered_seq_numbers);
-		free((*dbuf)->dgram_len);
 		free((*dbuf)->dgram_seq_numbers);
+		free((*dbuf)->dgram_len);
 		free((*dbuf)->msgs);
-		free((*dbuf)->write_iovecs);
-		free((*dbuf)->recv_iovecs);
+		free((*dbuf)->iov_write);
+		free((*dbuf)->iov_recv);
 		free(*dbuf);
 	}
 	*dbuf = NULL;
diff --git a/mcastseed/src/dgrambuf.h b/mcastseed/src/dgrambuf.h
index b74625d..3a94eee 100644
--- a/mcastseed/src/dgrambuf.h
+++ b/mcastseed/src/dgrambuf.h
@@ -9,9 +9,10 @@
 
 typedef struct dgrambuf_t *dgrambuf_t;
 
-dgrambuf_t dgrambuf_new(size_t dgram_count, size_t dgram_max_size, size_t dgram_header_size);
+dgrambuf_t dgrambuf_new(size_t dgram_slots, size_t dgram_max_size, size_t dgram_header_size, size_t iovec_slots);
 void dgrambuf_free(dgrambuf_t *dbuf);
 
+size_t dgrambuf_free_count(const dgrambuf_t);
 void dgrambuf_set_validate_func(dgrambuf_t dbuf, unsigned int (*func)(unsigned int, void *) );
 
 
diff --git a/mcastseed/src/mcastleech.c b/mcastseed/src/mcastleech.c
index 9315992..6760451 100644
--- a/mcastseed/src/mcastleech.c
+++ b/mcastseed/src/mcastleech.c
@@ -1,23 +1,26 @@
-/* client.c
+/*
+ * mcastleech.c - Multicast client for huge streams to be piped to other programs (partitions cloning)
+ *
+ * Copyright 2016 by Ludovic Pouzenc <ludovic@pouzenc.fr>
+ *
  * Greatly inspired from examples written by tmouse, July 2005
  * http://cboard.cprogramming.com/showthread.php?t=67469
- * Modified to run multi-platform by Christian Beier <dontmind@freeshell.org>.
  */
+#define _GNU_SOURCE /* See feature_test_macros(7) */
 
-#ifndef __MINGW32__
-#include <unistd.h>
-#endif
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
+#include <unistd.h> /* close() */
+#include <stdio.h> /* fprintf(), stderr */
+#include <stdlib.h> /* EXIT_SUCCESS */
 #include "msock.h" 
 #include "dgrambuf.h" 
 
 #define MTU 1500
 #define MULTICAST_RECV_BUF (MTU-20-8)
-#define MULTICAST_SO_RCVBUF 425984
+#define MULTICAST_SO_RCVBUF_WANTED 425984
+//XXX Make it dynamic, with the effective value of so_rcvbuf
+#define MAX_IOVEC (MULTICAST_SO_RCVBUF_WANTED / MULTICAST_RECV_BUF)
 #define DGRAM_HEADER_SIZE 8
+
 #define DEFAULT_MCAST_IP_STR "ff02::114"
 #define DEFAULT_PORT_STR "9000"
 
@@ -37,7 +40,7 @@ dgrambuf_t dgrambuf;
 
 /* Strings to print out representation of various states of the program */
 const char * const state_str[] = {
-	"exiting",
+	"start",
 	"wait_hello_and_connect_back",
 	"wait_start_and_start_job",
 	"receive_data",
@@ -49,6 +52,7 @@ const char * const state_str[] = {
 void die(char* msg);
 void usage(char *msg);
 void arg_parse(int argc, char* argv[]);
+void fsm_trace(int state);
 int get_available_mem_kb();
 void dgrambuf_init();
 uint32_t validate_data_dgram(unsigned int nread, void *recvbuf);
@@ -61,7 +65,6 @@ int receive_data();
 int finalize_job();
 int is_there_more_job();
 
-
 int main(int argc, char* argv[]) {
 	int state = 1; /* state of the "protocol" state machine */
 	int res;
@@ -71,7 +74,7 @@ int main(int argc, char* argv[]) {
 
 	/* Finite state machine */
 	while ( state > 0 ) {
-		fprintf(stderr, "Now in %s state\n", state_str[state]);
+		fsm_trace(state);
 		switch ( state ) {
 			case 1: state = (wait_hello_and_connect_back() == 0)?2:1; break;
 			case 2: state = (wait_start_and_start_job() == 0)?2:3; break;
@@ -84,6 +87,7 @@ int main(int argc, char* argv[]) {
 			case 5: state = (is_there_more_job() == 0)?2:0; break;
 		}
 	}
+	fsm_trace(state);
 
 	if ( mcast_sock > 0 ) {
 		close(mcast_sock);
@@ -115,7 +119,7 @@ int wait_hello_and_connect_back() {
 		close(mcast_sock);
 		mcast_sock = (SOCKET) -1;
 	}
-	mcast_sock = mcast_recv_socket(mcast_ip, port, MULTICAST_SO_RCVBUF);
+	mcast_sock = mcast_recv_socket(mcast_ip, port, MULTICAST_SO_RCVBUF_WANTED);
 	if(mcast_sock < 0) {
 		usage("Could not setup multicast socket. Wrong args given ?");
 	}	
@@ -187,7 +191,10 @@ void ack(uint32_t seq) {
 
 int finalize_job() {
 	//XXX Dummy test
-	dgrambuf_write(dgrambuf, 2);
+	ssize_t res;
+	while ( (res=dgrambuf_write(dgrambuf, 1)) > 0 ) {
+		fprintf(stderr, "dgrambuf_write => %zi\n", res);
+	}
 	return 0;	
 }
 int is_there_more_job() {
@@ -223,6 +230,21 @@ void arg_parse(int argc, char* argv[]) {
 	mcast_ip = (argc >= 3)?argv[2]:DEFAULT_MCAST_IP_STR;
 }
 
+void fsm_trace(int state) {
+	static int prev_state = 0;
+
+	if ( state < 0 ) {
+		fprintf(stderr, "Abnormal exit condition %i (from %s)", state, state_str[prev_state]);
+	} else	if ( prev_state != state) { 
+		if ( state == 0 ) {
+			fprintf(stderr, "Normal exit (from %s)\n",  state_str[prev_state]);
+		} else {
+			fprintf(stderr, "Now in %s (from %s)\n", state_str[state], state_str[prev_state]);
+		}
+		prev_state = state;
+	}
+}
+
 int get_available_mem_kb() {
 	char key[64];
 	int res, value, found=0;
@@ -249,23 +271,22 @@ void dgrambuf_init() {
 	size_t dgram_count;
 	int avail_mem = get_available_mem_kb();
 
-	if ( avail_mem < MULTICAST_SO_RCVBUF ) {
-		dgram_count = MULTICAST_SO_RCVBUF / MULTICAST_RECV_BUF;
+	if ( avail_mem < MULTICAST_SO_RCVBUF_WANTED ) {
+		dgram_count = MULTICAST_SO_RCVBUF_WANTED / MULTICAST_RECV_BUF;
 	} else {
 		dgram_count = avail_mem / MULTICAST_RECV_BUF / 2 * 1024;
 	}
 	//XXX Dummy
-	dgram_count = 3;
-	fprintf(stderr, "avail_mem == %i kb, dgram_count == %zi\n", avail_mem, dgram_count);
+	//dgram_count = 3;
 
 	/* Allocate dgrambuf */
-	dgrambuf = dgrambuf_new(dgram_count, MULTICAST_RECV_BUF, DGRAM_HEADER_SIZE);
+	dgrambuf = dgrambuf_new(dgram_count, MULTICAST_RECV_BUF, DGRAM_HEADER_SIZE, MAX_IOVEC);
 	if ( dgrambuf == NULL ) {
 		perror("dgrambuf_new/malloc");
 		exit(EXIT_FAILURE);
 	} 
 
-	//printf("dgrambuf_free_count() => %zi\n", dgrambuf_free_count(dgrambuf));
+	fprintf(stderr, "dgrambuf_free_count() => %zi\n", dgrambuf_free_count(dgrambuf));
 	dgrambuf_set_validate_func(dgrambuf, validate_data_dgram);
 }
 
diff --git a/mcastseed/src/mcastseed.c b/mcastseed/src/mcastseed.c
index f86af84..276ed92 100644
--- a/mcastseed/src/mcastseed.c
+++ b/mcastseed/src/mcastseed.c
@@ -1,19 +1,22 @@
-/* server.c
+/*
+ * mcastseed.c - Multicast sender for huge streams to be piped to other programs (partitions cloning)
+ *
+ * Copyright 2016 by Ludovic Pouzenc <ludovic@pouzenc.fr>
+ *
  * Greatly inspired from examples written by tmouse, July 2005
  * http://cboard.cprogramming.com/showthread.php?t=67469
- * Modified to run multi-platform by Christian Beier <dontmind@freeshell.org>.
  */
+#define _GNU_SOURCE /* See feature_test_macros(7) */
 
-#ifndef __MINGW32__
-#include <unistd.h> /* for usleep() */
-#endif
-#include <stdio.h>
-#include <stdlib.h>
+#include <unistd.h> /* close() */
+#include <stdio.h> /* fprintf(), stderr */
+#include <stdlib.h> /* atoi(), EXIT_SUCCESS */
 #include "msock.h"
 
 #define READ_BUF_LEN 256
 #define MAX_PENDING_CONNECTIONS 256
 #define MAX_CLIENTS 256
+
 #define DEFAULT_MCAST_IP_STR "ff02::114"
 #define DEFAULT_PORT_STR "9000"
 #define DEFAULT_MCAST_TTL 1
@@ -42,7 +45,7 @@ char readbuf[READ_BUF_LEN];
 
 /* Strings to print out representation of various states of the program */
 const char * const state_str[] = {
-	"exiting",
+	"start",
 	"send_hello",
 	"accept_pending_clients_or_wait_a_bit",
 	"start_job",
@@ -55,8 +58,9 @@ const char * const state_str[] = {
 void die(char* msg);
 void usage(char *msg);
 void arg_parse(int argc, char* argv[]);
-void unsetup_sockets();
+void fsm_trace(int state);
 void setup_sockets();
+void unsetup_sockets();
 
 /* Parts of the "protocol", definitions are after main() */
 int send_hello();
@@ -74,7 +78,7 @@ int main(int argc, char *argv[]) {
 
 	/* Finite state machine */
 	while ( state > 0 ) {
-		fprintf(stderr, "Now in %s state\n", state_str[state]);
+		fsm_trace(state);
 		switch ( state ) {
 			case 1: res = send_hello(); state = (res==0)?2:-1; break;
 			case 2: res = accept_pending_clients_or_wait_a_bit();
@@ -105,6 +109,7 @@ int main(int argc, char *argv[]) {
 							break;
 		}
 	}
+	fsm_trace(state);
 
 	unsetup_sockets();
 
@@ -261,24 +266,34 @@ int start_job() {
 	return 0;
 }
 
+void send_fake(char buf[], int paylen, int i) {
+	*( (uint32_t *) buf+1 ) = htonl(i);
+	snprintf(buf+29, 5, "%04i", i);
+	*( (char *) buf+33 ) = ')';
+	sendto(mcast_sock, buf, 8+paylen, 0, mcast_addr->ai_addr, mcast_addr->ai_addrlen);
+}
 
 int send_data() {
 	ssize_t nwrite;
-	char buf[] = "dataXXXXJe suis à la plage.";
+	char buf[] = "dataXXXXJe suis à la plage (XXXX).\n";
 	int paylen = strlen(buf)-8;
-	int seq = 1;
+	int i;
 
 	//XXX Dummy
-	*( (uint32_t *) buf+1 ) = htonl(3);
-	sendto(mcast_sock, buf, 8+paylen, 0, mcast_addr->ai_addr, mcast_addr->ai_addrlen);
-	*( (uint32_t *) buf+1 ) = htonl(4);
-	sendto(mcast_sock, buf, 8+paylen, 0, mcast_addr->ai_addr, mcast_addr->ai_addrlen);
-	*( (uint32_t *) buf+1 ) = htonl(2);
-	sendto(mcast_sock, buf, 8+paylen, 0, mcast_addr->ai_addr, mcast_addr->ai_addrlen);
-
-
-	*( (uint32_t *) buf+1 ) = htonl(seq);
+	send_fake(buf, paylen, 5);
+	send_fake(buf, paylen, 4);
+  for (i=6; i<=300; i+=2) {
+		send_fake(buf, paylen, i);
+	}
+  for (i=7; i<=300; i+=2) {
+		send_fake(buf, paylen, i);
+	}
+	send_fake(buf, paylen, 1);
+	send_fake(buf, paylen, 1);
+	send_fake(buf, paylen, 2);
 
+	*( (uint32_t *) buf+1 ) = htonl(3);
+	buf[22]='m', buf[23]='e', buf[24]='r'; buf[25]='.'; buf[26]='\n'; paylen = 19;
 	nwrite = sendto(mcast_sock, buf, 8+paylen, 0, mcast_addr->ai_addr, mcast_addr->ai_addrlen);
 	if ( nwrite < 0 ) {
 		perror("sendto() failed");
@@ -398,19 +413,18 @@ void arg_parse(int argc, char* argv[]) {
 		mcast_ttl = 1;
 }
 
-void unsetup_sockets() {
-	if ( ucast_sock > 0 ) {
-		close(ucast_sock);
-		ucast_sock = 0;
-	}
+void fsm_trace(int state) {
+	static int prev_state = 0;
 
-	if ( mcast_sock > 0 ) {
-		close(mcast_sock);
-		mcast_sock = 0;
-		if ( mcast_addr ) {
-			freeaddrinfo(mcast_addr);
-			mcast_addr = 0;
+	if ( state < 0 ) {
+		fprintf(stderr, "Abnormal exit condition %i (from %s)", state, state_str[prev_state]);
+	} else	if ( prev_state != state) { 
+		if ( state == 0 ) {
+			fprintf(stderr, "Normal exit (from %s)\n",  state_str[prev_state]);
+		} else {
+			fprintf(stderr, "Now in %s (from %s)\n", state_str[state], state_str[prev_state]);
 		}
+		prev_state = state;
 	}
 }
 
@@ -426,3 +440,19 @@ void setup_sockets() {
 			usage("Could not setup multicast socket. Wrong args given ?");
 }
 
+void unsetup_sockets() {
+	if ( ucast_sock > 0 ) {
+		close(ucast_sock);
+		ucast_sock = 0;
+	}
+
+	if ( mcast_sock > 0 ) {
+		close(mcast_sock);
+		mcast_sock = 0;
+		if ( mcast_addr ) {
+			freeaddrinfo(mcast_addr);
+			mcast_addr = 0;
+		}
+	}
+}
+
diff --git a/mcastseed/src/msock.c b/mcastseed/src/msock.c
index 8274710..e5df8d6 100644
--- a/mcastseed/src/msock.c
+++ b/mcastseed/src/msock.c
@@ -178,7 +178,7 @@ SOCKET mcast_recv_socket(char* multicastIP, char* multicastPort, int multicastRe
 	perror("getsockopt");
 	goto error;
     }
-    printf("tried to set socket receive buffer from %d to %d, got %d\n",
+    fprintf(stderr, "tried to set socket receive buffer from %d to %d, got %d\n",
 	   dfltrcvbuf, multicastRecvBufSize, optval);