pping: Make parsed protocols configurable

Add command-line flags for each protocol that pping should attempt to
parse and report RTTs for (currently -T/--tcp and -C/--icmp). If no
protocol is specified assume TCP. To clarify this, output a message
before start on how ePPing has been configured (stating output format,
tracked protocols and which interface to run on).

Additionally, as the ppviz format was only designed for TCP it does
not have any field for which protocol an entry belongs to. Therefore,
emit a warning in case the user selects the ppviz format with anything
other than TCP.

Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>

Author: simosund

pping/pping.c

@@ -104,6 +104,8 @@ static const struct option long_options[] = {
 	{ "cleanup-interval", required_argument, NULL, 'c' }, // Map cleaning interval in s, 0 to disable
 	{ "format",           required_argument, NULL, 'F' }, // Which format to output in (standard/json/ppviz)
 	{ "ingress-hook",     required_argument, NULL, 'I' }, // Use tc or XDP as ingress hook
+	{ "tcp",              no_argument,       NULL, 'T' }, // Calculate and report RTTs for TCP traffic (with TCP timestamps)
+	{ "icmp",             no_argument,       NULL, 'C' }, // Calculate and report RTTs for ICMP echo-reply traffic
 	{ 0, 0, NULL, 0 }
 };
 
@@ -169,8 +171,10 @@ static int parse_arguments(int argc, char *argv[], struct pping_config *config)
 
 	config->ifindex = 0;
 	config->force = false;
+	config->bpf_config.track_tcp = false;
+	config->bpf_config.track_icmp = false;
 
-	while ((opt = getopt_long(argc, argv, "hfi:r:c:F:I:", long_options,
+	while ((opt = getopt_long(argc, argv, "hfTCi:r:c:F:I:", long_options,
 				  NULL)) != -1) {
 		switch (opt) {
 		case 'i':
@@ -235,6 +239,12 @@ static int parse_arguments(int argc, char *argv[], struct pping_config *config)
 			config->force = true;
 			config->xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
 			break;
+		case 'T':
+			config->bpf_config.track_tcp = true;
+			break;
+		case 'C':
+			config->bpf_config.track_icmp = true;
+			break;
 		case 'h':
 			printf("HELP:\n");
 			print_usage(argv);
@@ -254,6 +264,23 @@ static int parse_arguments(int argc, char *argv[], struct pping_config *config)
 	return 0;
 }
 
+const char *tracked_protocols_to_str(struct pping_config *config)
+{
+	bool tcp = config->bpf_config.track_tcp;
+	bool icmp = config->bpf_config.track_icmp;
+	return tcp && icmp ? "TCP, ICMP" : tcp ? "TCP" : "ICMP";
+}
+
+const char *output_format_to_str(enum PPING_OUTPUT_FORMAT format)
+{
+	switch (format) {
+	case PPING_OUTPUT_STANDARD: return "standard";
+	case PPING_OUTPUT_JSON: return "json";
+	case PPING_OUTPUT_PPVIZ: return "ppviz";
+	default: return "unkown format";
+	}
+}
+
 void abort_program(int sig)
 {
 	keep_running = 0;
@@ -985,6 +1012,14 @@ int main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
+	if (!config.bpf_config.track_tcp && !config.bpf_config.track_icmp)
+		config.bpf_config.track_tcp = true;
+
+	if (config.bpf_config.track_icmp &&
+	    config.output_format == PPING_OUTPUT_PPVIZ)
+		fprintf(stderr,
+			"Warning: ppviz format mainly intended for TCP traffic, but may now include ICMP traffic as well\n");
+
 	switch (config.output_format) {
 	case PPING_OUTPUT_STANDARD:
 		print_event_func = print_event_standard;
@@ -997,6 +1032,10 @@ int main(int argc, char *argv[])
 		break;
 	}
 
+	fprintf(stderr, "Starting ePPing in %s mode tracking %s on %s\n",
+		output_format_to_str(config.output_format),
+		tracked_protocols_to_str(&config), config.ifname);
+
 	err = load_attach_bpfprogs(&obj, &config);
 	if (err) {
 		fprintf(stderr,

pping/pping.h

@@ -34,6 +34,9 @@ enum __attribute__((__packed__)) flow_event_source {
 
 struct bpf_config {
 	__u64 rate_limit;
+	bool track_tcp;
+	bool track_icmp;
+	__u8 reserved[6];
 };
 
 /*

pping/pping_kern.c

@@ -286,14 +286,15 @@ static int parse_packet_identifier(struct parsing_context *ctx,
 	}
 
 	// Parse identifer from suitable protocol
-	if (p_id->flow.proto == IPPROTO_TCP)
+	if (config.track_tcp && p_id->flow.proto == IPPROTO_TCP)
 		err = parse_tcp_identifier(ctx, &saddr->port, &daddr->port, fei,
 					   &p_id->identifier);
-	else if (p_id->flow.proto == IPPROTO_ICMPV6 &&
+	else if (config.track_icmp && p_id->flow.proto == IPPROTO_ICMPV6 &&
 		 p_id->flow.ipv == AF_INET6)
 		err = parse_icmp6_identifier(ctx, &saddr->port, &daddr->port,
 					     fei, &p_id->identifier);
-	else if (p_id->flow.proto == IPPROTO_ICMP && p_id->flow.ipv == AF_INET)
+	else if (config.track_icmp && p_id->flow.proto == IPPROTO_ICMP &&
+		 p_id->flow.ipv == AF_INET)
 		err = parse_icmp_identifier(ctx, &saddr->port, &daddr->port,
 					    fei, &p_id->identifier);
 	else