traceroute6: explain all number constants

Some of these values are in kernel user api, but because includes redefine
same variable names using system headers is not an option.  While on it add
icmp types that were earlier unknown to traceroute6.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

1 files changed, 75 insertions, 35 deletions

diff --git a/traceroute6.c b/traceroute6.c
index 9e91b68..a324570 100644
--- a/traceroute6.c
+++ b/traceroute6.c
@@ -267,7 +267,47 @@
 # define SOL_IPV6 IPPROTO_IPV6
 #endif
 
-#define	MAXPACKET	65535
+enum {
+	DEFAULT_PROBES = 3,
+	DEFAULT_HOPS = 30,
+	DEFAULT_PORT = 32768 + 666,
+	DEFAULT_WAIT = 5,
+	PACKET_SIZE = 512,
+	MAXPACKET = 65535,
+
+	/*
+	 * The following are copy from linux/icmpv6.h that cannot be
+	 * included because icmp6_filter prototype is redefined in
+	 * netinet/icmp6.h header.
+	 */
+	ICMPV6_DEST_UNREACH = 1,
+	ICMPV6_PKT_TOOBIG = 2,
+	ICMPV6_TIME_EXCEED = 3,
+	ICMPV6_PARAMPROB = 4,
+	ICMPV6_ECHO_REQUEST = 128,
+	ICMPV6_ECHO_REPLY = 129,
+	ICMPV6_MGM_QUERY = 130,
+	ICMPV6_MGM_REPORT = 131,
+	ICMPV6_MGM_REDUCTION = 132,
+	ICMPV6_NI_QUERY = 139,
+	ICMPV6_NI_REPLY = 140,
+	ICMPV6_MLD2_REPORT = 143,
+	ICMPV6_DHAAD_REQUEST = 144,
+	ICMPV6_DHAAD_REPLY = 145,
+	ICMPV6_MOBILE_PREFIX_SOL = 146,
+	ICMPV6_MOBILE_PREFIX_ADV = 147,
+
+	/*
+	 * ICMP codes for neighbour discovery messages.  These are from
+	 * linux kernel source include/net/ndisc.h file.  The user api
+	 * includes does not have these values.
+	 */
+	NDISC_ROUTER_SOLICITATION = 133,
+	NDISC_ROUTER_ADVERTISEMENT = 134,
+	NDISC_NEIGHBOUR_SOLICITATION = 135,
+	NDISC_NEIGHBOUR_ADVERTISEMENT = 136,
+	NDISC_REDIRECT = 137,
+};
 
 #ifndef FD_SET
 # define NFDBITS         (8 * sizeof(fd_set))
@@ -279,7 +319,7 @@
 #endif
 
 struct run_state {
-	unsigned char packet[512];	/* last inbound (icmp) packet */
+	unsigned char packet[PACKET_SIZE];	/* last inbound (icmp) packet */
 	int icmp_sock;			/* receive (icmp) socket file descriptor */
 	int sndsock;			/* send (udp) socket file descriptor */
 	char *sendbuff;
@@ -318,7 +358,7 @@ static int wait_for_reply(struct run_state *ctl, struct sockaddr_in6 *from,
 	fd_set fds;
 	static struct timeval wait;
 	ssize_t cc = 0;
-	char cbuf[512];
+	char cbuf[PACKET_SIZE];
 
 	FD_ZERO(&fds);
 	FD_SET(ctl->icmp_sock, &fds);
@@ -431,48 +471,48 @@ static char const *pr_type(const uint8_t t)
 		/* Unknown */
 	case 0:
 		return "Error";
-	case 1:
-		/* ICMP6_DST_UNREACH: */
+	case ICMPV6_DEST_UNREACH:
 		return "Destination Unreachable";
-	case 2:
-		/* ICMP6_PACKET_TOO_BIG: */
+	case ICMPV6_PKT_TOOBIG:
 		return "Packet Too Big";
-	case 3:
-		/* ICMP6_TIME_EXCEEDED */
+	case ICMPV6_TIME_EXCEED:
 		return "Time Exceeded in Transit";
-	case 4:
-		/* ICMP6_PARAM_PROB */
+	case ICMPV6_PARAMPROB:
 		return "Parameter Problem";
-	case 128:
-		/* ICMP6_ECHO_REQUEST */
+	case ICMPV6_ECHO_REQUEST:
 		return "Echo Request";
-	case 129:
-		/* ICMP6_ECHO_REPLY */
+	case ICMPV6_ECHO_REPLY:
 		return "Echo Reply";
-	case 130:
-		/* ICMP6_MEMBERSHIP_QUERY */
+	case ICMPV6_MGM_QUERY:
 		return "Membership Query";
-	case 131:
-		/* ICMP6_MEMBERSHIP_REPORT */
+	case ICMPV6_MGM_REPORT:
 		return "Membership Report";
-	case 132:
-		/* ICMP6_MEMBERSHIP_REDUCTION */
+	case ICMPV6_MGM_REDUCTION:
 		return "Membership Reduction";
-	case 133:
-		/* ND_ROUTER_SOLICIT */
+	case NDISC_ROUTER_SOLICITATION:
 		return "Router Solicitation";
-	case 134:
-		/* ND_ROUTER_ADVERT */
+	case NDISC_ROUTER_ADVERTISEMENT:
 		return "Router Advertisement";
-	case 135:
-		/* ND_NEIGHBOR_SOLICIT */
+	case NDISC_NEIGHBOUR_SOLICITATION:
 		return "Neighbor Solicitation";
-	case 136:
-		/* ND_NEIGHBOR_ADVERT */
+	case NDISC_NEIGHBOUR_ADVERTISEMENT:
 		return "Neighbor Advertisement";
-	case 137:
-		/* ND_REDIRECT */
+	case NDISC_REDIRECT:
 		return "Redirect";
+	case ICMPV6_NI_QUERY:
+		return "Neighbor Query";
+	case ICMPV6_NI_REPLY:
+		return "Neighbor Reply";
+	case ICMPV6_MLD2_REPORT:
+		return "Multicast Listener Report packet";
+	case ICMPV6_DHAAD_REQUEST:
+		return "Home Agent Address Discovery Request Message";
+	case ICMPV6_DHAAD_REPLY:
+		return "Home Agent Address Discovery Reply message";
+	case ICMPV6_MOBILE_PREFIX_SOL:
+		return "Mobile Prefix Solicitation Message";
+	case ICMPV6_MOBILE_PREFIX_ADV:
+		return "Mobile Prefix Solicitation Advertisement";
 	default:
 		return "OUT-OF-RANGE";
 	}
@@ -584,10 +624,10 @@ static __attribute__((noreturn)) void usage(void)
 int main(int argc, char **argv)
 {
 	struct run_state ctl = {
-		.nprobes = 3,
-		.max_ttl = 30,
-		.port = 32768 + 666,
-		.waittime = 5,
+		.nprobes = DEFAULT_PROBES,
+		.max_ttl = DEFAULT_HOPS,
+		.port = DEFAULT_PORT,
+		.waittime = DEFAULT_WAIT,
 		0
 	};
 	char pa[NI_MAXHOST];