Signal handling and statistics at exit

git-svn-id: file:///var/svn/2012-tzsp/trunk@7 147d2d3d-d0bd-48ea-923a-d90ac20f5906

1 files changed, 66 insertions, 13 deletions

diff --git a/pcap2tzsp.c b/pcap2tzsp.c
index 701944c..e548ed9 100644
--- a/pcap2tzsp.c
+++ b/pcap2tzsp.c
@@ -1,8 +1,12 @@
+/* Library dependencies :
+	libpcap (sudo apt-get install libpcap0.8-dev)
+*/
 
 /* Basics */
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <signal.h>
 
 /* Args parsing and basename() for usage */
 #include <getopt.h>
@@ -19,13 +23,15 @@
 #include <pcap.h>
 #include <sys/time.h>
 
+/* Time management (for bwlimit) */
+#include <time.h>
+
+/* Option default values (as strings) */
 #define DEFAULT_FILTER "not ( icmp[icmptype]=icmp-unreach or (udp and dst %s and port %s) )"
 #define DEFAULT_HOST "127.0.0.1"
 #define DEFAULT_PORT "37008"
 #define DEFAULT_SNAPLEN "70"
-/* 70 bytes captured packets will to sent in ~128 bytes frames when encapsulated */
 
-#define UDP_SEND_BUFLEN 1500
 /* MAX_TZSP_PAYLOAD is for not trying to send TZSP packets greater than the interface MTU 
    MAX_TZSP_PAYLOAD =  MTU - IP header - UDP header - TZSP header 
    I am assuming the following :
@@ -33,12 +39,15 @@
      - MTU is assumed to be 1500 for now
 */
 #define MAX_TZSP_PAYLOAD (1500-20-8-16)
+#define UDP_SEND_BUFLEN 1500
 #define MIN_BYTES_TO_CAPTURE 16
 #define MAX_BYTES_TO_CAPTURE (1500-20-8-16)
 
 
 /*
 TODO List
+  * Crash at exit if no -i supplied
+  * TZSP TAGPACKET_COUNT field
   * Resolution DNS host -> IP (c'est l'ip qu'il faut dans le filtre et pas le host !!)
   * Stats nombre de packets loupés ?
   * Implémenter une bwlimit en sortie (ptks/s et/ou bytes/s)
@@ -57,7 +66,8 @@ void process_packet(u_char *void_args, const struct pcap_pkthdr* pkthdr, const u
 
 /* Custom types definition */
 typedef struct _process_packet_args {
-	uint64_t pkt_count;
+	uint64_t captured_pkt_count;
+	uint64_t sent_pkt_count;
 	int udp_socket;
 	struct sockaddr_in udp_sockaddr;
 } process_packet_args_t;
@@ -74,6 +84,7 @@ static char *opt_host=NULL;
 static char *opt_port=NULL;
 static char *opt_snaplen=NULL;
 
+pcap_t *pcap_handle = NULL; 
 
 void usage(char progname[]) {
 	printf("Usage : %s [--verbose] [--brief] [-i <iface>] [-h <host>] [-p <port>] [custom_pcap_filter]\n", progname);
@@ -84,6 +95,22 @@ void usage(char progname[]) {
 	exit(1);
 }
 
+void sig_handler(int signo) {
+	static int pcap_break=0;
+
+	switch (signo) {
+		case SIGINT:
+			if (pcap_break==0) {
+				pcap_break=1;
+				//fprintf(stderr, "DEBUG : pcap_breakloop(pcap_handle);\n");
+				pcap_breakloop(pcap_handle);
+			}
+			break;
+		default:
+			fprintf(stderr, "Catched an unhandled signal : %i\n", signo);
+	}
+}
+
 int main(int argc, char *argv[]) {
 
 	/* Command line args parsing */
@@ -170,6 +197,7 @@ int main(int argc, char *argv[]) {
 	//printf ("Capture filter will be : '%s' (pcap_filter_len-j==%i)\n", pcap_filter, pcap_filter_len-j);
 
 
+	signal(SIGINT, sig_handler);
 	/* Run the capture loop */
 	capture_loop(pcap_filter);
 
@@ -186,10 +214,12 @@ int main(int argc, char *argv[]) {
 
 void capture_loop(char pcap_filter[]) { 
 
-	pcap_t *pcap_handle = NULL; 
+	//Global for signal handling
+	//pcap_t *pcap_handle = NULL; 
 	static char *pcap_device=NULL;
 	char pcap_errbuf[PCAP_ERRBUF_SIZE];
 	struct bpf_program pcap_filter_prog;
+	struct pcap_stat stat;
 	process_packet_args_t process_packet_args;
 	int snaplen;
 
@@ -213,7 +243,7 @@ void capture_loop(char pcap_filter[]) {
 		exit(12);
 	}
 
-	//Already done : memset((char *) &(process_packet_args.udp_sockaddr), 0, sockaddr_len);
+	/* Already done : memset((char *) &(process_packet_args.udp_sockaddr), 0, sockaddr_len); */
 	process_packet_args.udp_sockaddr.sin_family = AF_INET;
 	process_packet_args.udp_sockaddr.sin_port = htons(atoi(opt_port));
 	if (inet_aton(opt_host, &(process_packet_args.udp_sockaddr.sin_addr))==0) {
@@ -253,13 +283,23 @@ void capture_loop(char pcap_filter[]) {
 		exit(10);
 	}
 
-	/* Loop forever & call process_packet() for every received packet*/ 
+	/* Loop forever & call process_packet() for every received packet */ 
 	/* For valgrind tests : if ( pcap_loop(pcap_handle, 1000000, process_packet, (u_char *)&process_packet_args) == -1){ */
 	if ( pcap_loop(pcap_handle, -1, process_packet, (u_char *)&process_packet_args) == -1) {
 		fprintf(stderr, "ERROR: %s\n", pcap_geterr(pcap_handle) );
 		exit(25);
 	}
 
+	fprintf(stderr, "\n%llu packets captured\n%llu TZSP packets sent\n",
+		 process_packet_args.captured_pkt_count, process_packet_args.sent_pkt_count);
+	
+	if (pcap_stats(pcap_handle, &stat) == -1) {
+		fprintf(stderr, "ERROR: %s\n", pcap_geterr(pcap_handle) );
+		exit(26);
+	}
+	fprintf(stderr, "%u packets received by filter\n%u packets dropped by kernel\n",
+		stat.ps_recv, stat.ps_drop);
+
 	pcap_close(pcap_handle);
 	close(process_packet_args.udp_socket);
 }
@@ -271,7 +311,7 @@ void capture_loop(char pcap_filter[]) {
 void process_packet(u_char *void_args, const struct pcap_pkthdr* pkthdr, const u_char * packet) {
 
 	static time_t old_tv_sec=0;
-	static uint64_t old_pkt_count=0;
+	static uint64_t old_captured_pkt_count=0;
 
 	int res;
 	double throughput;
@@ -279,21 +319,26 @@ void process_packet(u_char *void_args, const struct pcap_pkthdr* pkthdr, const u
 	uint32_t ts; /* In network byte order */
 	uint16_t len; /* In network byte order */
 	char buf[UDP_SEND_BUFLEN];
+	/* struct timespec ts_reqsleep; For simulation */
 
 	process_packet_args_t *args=(process_packet_args_t *)void_args; 
 
-	/* Packet counting and displaying (max once by second) */
-	args->pkt_count++;
+	/* Catpured packet counting and displaying (max once by second) */
+	args->captured_pkt_count++;
 
 	if (old_tv_sec != pkthdr->ts.tv_sec) {
-		//printf("DEBUG : throughput=((double)  %llu - %llu ) / (  %u - %u )\n", args->pkt_count, old_pkt_count, pkthdr->ts.tv_sec, old_tv_sec);
-		throughput=((double) args->pkt_count - old_pkt_count ) / (pkthdr->ts.tv_sec - old_tv_sec);
-		printf("\rPacket Count: %20llu (%8.1f pkt/s)", args->pkt_count, throughput);
+		/*printf("DEBUG : throughput=((double)  %llu - %llu ) / (  %u - %u )\n",
+			args->captured_pkt_count, old_captured_pkt_count, pkthdr->ts.tv_sec, old_tv_sec);
+		*/
+		throughput=((double) args->captured_pkt_count - old_captured_pkt_count ) / (pkthdr->ts.tv_sec - old_tv_sec);
+		printf("\rPacket Count: %20llu (%8.1f pkt/s)", args->captured_pkt_count, throughput);
 		fflush(stdout);
 		old_tv_sec=pkthdr->ts.tv_sec;
-		old_pkt_count= args->pkt_count;
+		old_captured_pkt_count= args->captured_pkt_count;
 	}
 
+	//TODO : bwlimit HERE (not before, no after)
+
 	/* Variable fields for TZSP packet */
 	ts=htonl((uint32_t) pkthdr->ts.tv_sec); /* TODO : this cast is bullshit ? */
 	len=htons((uint16_t) pkthdr->len);
@@ -327,6 +372,14 @@ void process_packet(u_char *void_args, const struct pcap_pkthdr* pkthdr, const u
 	res=sendto(args->udp_socket, buf, 16+pkthdr->caplen, 0, (struct sockaddr *)&(args->udp_sockaddr), sockaddr_len);
 	if (res==-1) {
 		fprintf(stderr, "sendto() error\n");
+	} else {
+		args->sent_pkt_count++;
 	}
+
+	/* Slow sending simulation
+	ts_reqsleep.tv_sec=0;
+	ts_reqsleep.tv_nsec=10000;
+	nanosleep(&ts_reqsleep, NULL);
+	*/
 }