Merge pull request #2110 from msablic/pim_mtrace_group

pimd: adding querying of state to mtrace

doc/manpages/mtracebis.rst

@@ -9,17 +9,22 @@ SYNOPSIS
 ========
 |PROGRAM| |synopsis-options-hv|
 
-|PROGRAM| <multicast source>
+|PROGRAM| <multicast source> [<multicast group>]
 
 DESCRIPTION
 ===========
-|PROGRAM| is a program to initiate multicast traceroute, or "mtrace", queries.
+|PROGRAM| is a program for initiating multicast traceroute, or "mtrace", queries.
 
-The initial version of the program requires multicast source IP address and
+It can initiate two types of mtrace queries: weak and group.
-initiates a weak traceroute across the network. This tests whether the
+
-interfaces towards the source are multicast enabled. The first query sent is a
+Weak tests whether the interfaces towards the source are multicast enabled and is
-full query, capable of crossing the network all the way to the source. If this
+initiated by supplying only the multicast source address.
-fails, hop-by-hop queries are initiated.
+
+Group tests whether there is multicast routing protocol state for particular
+multicast group and is initiated by supplying mutlicast source and group.
+
+The first query sent is a full query, capable of crossing the network all the way
+to the source. If this fails, hop-by-hop queries are initiated.
 
 Hop-by-hop queries start by requesting only a response from the nearest router.
 Following that, next query is extended to the next two routers, and so on...

pimd/mtracebis.c

@@ -22,6 +22,7 @@
 #include "pim_igmp_mtrace.h"
 
 #include "checksum.h"
+#include "prefix.h"
 #include "mtracebis_routeget.h"
 
 #include <sys/select.h>
@@ -50,7 +51,8 @@
 static const char *progname;
 static void usage(void)
 {
-	fprintf(stderr, "Usage : %s <multicast source>\n", progname);
+	fprintf(stderr, "Usage : %s <multicast source> [<multicast group>]\n",
+		progname);
 }
 static void version(void)
 {
@@ -170,9 +172,21 @@ static void print_fwd_code(uint32_t fwd_code)
 static void print_rsp(struct igmp_mtrace_rsp *rsp)
 {
 	print_host(rsp->outgoing);
-	if (rsp->fwd_code == 0) {
+	if (rsp->fwd_code == 0 || rsp->fwd_code == MTRACE_FWD_CODE_REACHED_RP) {
 		print_rtg_proto(rsp->rtg_proto);
 		printf(" ");
+		if (rsp->fwd_code == MTRACE_FWD_CODE_REACHED_RP)
+			printf("(RP) ");
+		if (rsp->rtg_proto == MTRACE_RTG_PROTO_PIM) {
+			switch (rsp->src_mask) {
+			case MTRACE_SRC_MASK_GROUP:
+				printf("(*,G) ");
+				break;
+			case MTRACE_SRC_MASK_SOURCE:
+				printf("(S,G) ");
+				break;
+			}
+		}
 		print_fwd_ttl(rsp->fwd_ttl);
 	} else {
 		print_fwd_code(rsp->fwd_code);
@@ -351,6 +365,7 @@ static bool check_end(struct igmp_mtrace *mtrace, int hops)
 int main(int argc, char *const argv[])
 {
 	struct in_addr mc_source;
+	struct in_addr mc_group;
 	struct in_addr iface_addr;
 	struct in_addr gw_addr;
 	struct in_addr mtrace_addr;
@@ -370,6 +385,7 @@ int main(int argc, char *const argv[])
 	int i, j;
 	char ifname[IF_NAMESIZE];
 	char mbuf[MTRACE_BUF_LEN];
+	bool not_group;
 
 	mtrace_addr.s_addr = inet_addr("224.0.1.32");
 
@@ -385,7 +401,7 @@ int main(int argc, char *const argv[])
 	else
 		progname = argv[0];
 
-	if (argc != 2) {
+	if (argc != 2 && argc != 3) {
 		usage();
 		exit(EXIT_FAILURE);
 	}
@@ -416,11 +432,28 @@ int main(int argc, char *const argv[])
 	}
 	if (inet_pton(AF_INET, argv[1], &mc_source) != 1) {
 		usage();
-		fprintf(stderr, "%s: %s not a valid IPv4 address\n", argv[0],
+		fprintf(stderr, "%s: %s is not a valid IPv4 address\n", argv[0],
 			argv[1]);
 		exit(EXIT_FAILURE);
 	}
 
+	mc_group.s_addr = 0;
+	not_group = false;
+
+	if (argc == 3) {
+		if (inet_pton(AF_INET, argv[2], &mc_group) != 1)
+			not_group = true;
+		if (!not_group && !IPV4_CLASS_DE(ntohl(mc_group.s_addr)))
+			not_group = true;
+	}
+
+	if (not_group) {
+		usage();
+		fprintf(stderr, "%s: %s is not a valid IPv4 group address\n",
+			argv[0], argv[2]);
+		exit(EXIT_FAILURE);
+	}
+
 	ifindex = routeget(mc_source, &iface_addr, &gw_addr);
 	if (ifindex < 0) {
 		fprintf(stderr, "%s: failed to get route to source %s\n",
@@ -441,7 +474,7 @@ int main(int argc, char *const argv[])
 	mtrace.type = PIM_IGMP_MTRACE_QUERY_REQUEST;
 	mtrace.hops = hops;
 	mtrace.checksum = 0;
-	mtrace.grp_addr.s_addr = 0;
+	mtrace.grp_addr = mc_group;
 	mtrace.src_addr = mc_source;
 	mtrace.dst_addr = iface_addr;
 	mtrace.rsp_addr = unicast ? iface_addr : mtrace_addr;

pimd/pim_igmp_mtrace.c

@@ -17,6 +17,8 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+/* based on draft-ietf-idmr-traceroute-ipm-07 */
+
 #include <zebra.h>
 
 #include "pimd.h"
@@ -56,15 +58,131 @@ static struct in_addr mtrace_primary_address(struct interface *ifp)
 	return any;
 }
 
+static bool mtrace_fwd_info_weak(struct pim_instance *pim,
+				    struct igmp_mtrace *mtracep,
+				    struct igmp_mtrace_rsp *rspp,
+				    struct interface **ifpp)
+{
+	struct pim_nexthop nexthop;
+	struct interface *ifp_in;
+	struct in_addr nh_addr;
+	int ret;
+	char nexthop_str[INET_ADDRSTRLEN];
+
+	nh_addr.s_addr = 0;
+
+	memset(&nexthop, 0, sizeof(nexthop));
+
+	ret = pim_nexthop_lookup(pim, &nexthop, mtracep->src_addr, 1);
+
+	if (ret != 0) {
+		if (PIM_DEBUG_MTRACE)
+			zlog_debug("mtrace not found neighbor");
+		return false;
+	}
+
+	if (PIM_DEBUG_MTRACE)
+		zlog_debug("mtrace pim_nexthop_lookup OK");
+
+	if (PIM_DEBUG_MTRACE)
+		zlog_warn("mtrace next_hop=%s",
+			  inet_ntop(nexthop.mrib_nexthop_addr.family,
+				    &nexthop.mrib_nexthop_addr.u.prefix,
+				    nexthop_str, sizeof(nexthop_str)));
+
+	if (nexthop.mrib_nexthop_addr.family == AF_INET)
+		nh_addr = nexthop.mrib_nexthop_addr.u.prefix4;
+
+	ifp_in = nexthop.interface;
+
+	/* return interface for forwarding mtrace packets */
+	*ifpp = ifp_in;
+
+	/* 6.2.2. 4. Fill in the Incoming Interface Address... */
+	rspp->incoming = mtrace_primary_address(ifp_in);
+	rspp->prev_hop = nh_addr;
+	rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT);
+	rspp->total = htonl(MTRACE_UNKNOWN_COUNT);
+	rspp->rtg_proto = MTRACE_RTG_PROTO_PIM;
+	return true;
+}
+
+static bool mtrace_fwd_info(struct pim_instance *pim,
+			    struct igmp_mtrace *mtracep,
+			    struct igmp_mtrace_rsp *rspp,
+			    struct interface **ifpp)
+{
+	struct prefix_sg sg;
+	struct pim_upstream *up;
+	struct interface *ifp_in;
+	struct in_addr nh_addr;
+	uint32_t total;
+	char up_str[INET_ADDRSTRLEN];
+
+	memset(&sg, 0, sizeof(struct prefix_sg));
+	sg.src = mtracep->src_addr;
+	sg.grp = mtracep->grp_addr;
+
+	up = pim_upstream_find(pim, &sg);
+
+	if (!up) {
+		sg.src.s_addr = 0;
+		up = pim_upstream_find(pim, &sg);
+	}
+
+	if (!up)
+		return false;
+
+	ifp_in = up->rpf.source_nexthop.interface;
+	nh_addr = up->rpf.source_nexthop.mrib_nexthop_addr.u.prefix4;
+	total = htonl(MTRACE_UNKNOWN_COUNT);
+
+	if (PIM_DEBUG_MTRACE)
+		zlog_debug("fwd_info: upstream next hop=%s",
+			   inet_ntop(AF_INET, &(nh_addr), up_str,
+				     sizeof(up_str)));
+
+	if (up->channel_oil)
+		total = up->channel_oil->cc.pktcnt;
+
+	/* return interface for forwarding mtrace packets */
+	*ifpp = ifp_in;
+
+	/* 6.2.2. 4. Fill in the Incoming Interface Address... */
+	rspp->incoming = mtrace_primary_address(ifp_in);
+	rspp->prev_hop = nh_addr;
+	rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT);
+	rspp->total = total;
+	rspp->rtg_proto = MTRACE_RTG_PROTO_PIM;
+
+	/* 6.2.2. 4. Fill in ... S, and Src Mask */
+	if (sg.src.s_addr) {
+		rspp->s = 1;
+		rspp->src_mask = MTRACE_SRC_MASK_SOURCE;
+	} else {
+		rspp->s = 0;
+		rspp->src_mask = MTRACE_SRC_MASK_GROUP;
+	}
+
+	return true;
+}
+
+static void mtrace_rsp_set_fwd_code(struct igmp_mtrace_rsp *mtrace_rspp,
+				    enum mtrace_fwd_code fwd_code)
+{
+	if (mtrace_rspp->fwd_code == MTRACE_FWD_CODE_NO_ERROR)
+		mtrace_rspp->fwd_code = fwd_code;
+}
+
 static void mtrace_rsp_init(struct igmp_mtrace_rsp *mtrace_rspp)
 {
 	mtrace_rspp->arrival = 0;
 	mtrace_rspp->incoming.s_addr = 0;
 	mtrace_rspp->outgoing.s_addr = 0;
 	mtrace_rspp->prev_hop.s_addr = 0;
-	mtrace_rspp->in_count = MTRACE_UNKNOWN_COUNT;
+	mtrace_rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT);
-	mtrace_rspp->out_count = MTRACE_UNKNOWN_COUNT;
+	mtrace_rspp->out_count = htonl(MTRACE_UNKNOWN_COUNT);
-	mtrace_rspp->total = MTRACE_UNKNOWN_COUNT;
+	mtrace_rspp->total = htonl(MTRACE_UNKNOWN_COUNT);
 	mtrace_rspp->rtg_proto = 0;
 	mtrace_rspp->fwd_ttl = 0;
 	mtrace_rspp->mbz = 0;
@@ -394,7 +512,6 @@ static int mtrace_forward_packet(struct pim_instance *pim, struct ip *ip_hdr)
 		return mtrace_un_forward_packet(pim, ip_hdr, NULL);
 }
 
-/* 6.5 Sending Traceroute Responses */
 static int mtrace_send_mc_response(struct pim_instance *pim,
 				   struct igmp_mtrace *mtracep,
 				   size_t mtrace_len)
@@ -439,6 +556,7 @@ static int mtrace_send_mc_response(struct pim_instance *pim,
 	return ret;
 }
 
+/* 6.5 Sending Traceroute Responses */
 static int mtrace_send_response(struct pim_instance *pim,
 				struct igmp_mtrace *mtracep, size_t mtrace_len)
 {
@@ -496,7 +614,6 @@ int igmp_mtrace_recv_qry_req(struct igmp_sock *igmp, struct ip *ip_hdr,
 {
 	static uint32_t qry_id, qry_src;
 	char mtrace_buf[MTRACE_HDR_SIZE + MTRACE_MAX_HOPS * MTRACE_RSP_SIZE];
-	struct pim_nexthop nexthop;
 	struct interface *ifp;
 	struct interface *out_ifp;
 	struct pim_interface *pim_ifp;
@@ -505,12 +622,13 @@ int igmp_mtrace_recv_qry_req(struct igmp_sock *igmp, struct ip *ip_hdr,
 	struct igmp_mtrace_rsp *rspp;
 	struct in_addr nh_addr;
 	enum mtrace_fwd_code fwd_code = MTRACE_FWD_CODE_NO_ERROR;
-	int ret;
 	size_t r_len;
 	int last_rsp_ind = 0;
 	size_t mtrace_len;
 	uint16_t recv_checksum;
 	uint16_t checksum;
+	bool reached_source;
+	bool fwd_info;
 
 	ifp = igmp->interface;
 	pim_ifp = ifp->info;
@@ -575,6 +693,8 @@ int igmp_mtrace_recv_qry_req(struct igmp_sock *igmp, struct ip *ip_hdr,
 			}
 			/* Unicast query on wrong interface */
 			fwd_code = MTRACE_FWD_CODE_WRONG_IF;
+			if (PIM_DEBUG_MTRACE)
+				zlog_debug("Multicast query on wrong interface");
 		}
 		if (qry_id == mtracep->qry_id && qry_src == from.s_addr) {
 			if (PIM_DEBUG_MTRACE)
@@ -619,16 +739,19 @@ int igmp_mtrace_recv_qry_req(struct igmp_sock *igmp, struct ip *ip_hdr,
 
 	/* 6.2.2. Normal Processing */
 
-	/* 6.2.2. 1. */
+	/* 6.2.2. 1. If there is room in the current buffer? */
 
 	if (last_rsp_ind == MTRACE_MAX_HOPS) {
+		/* ...there was no room... */
 		mtracep->rsp[MTRACE_MAX_HOPS - 1].fwd_code =
 			MTRACE_FWD_CODE_NO_SPACE;
 		return mtrace_send_response(pim_ifp->pim, mtracep,
 					    igmp_msg_len);
 	}
 
-	/* calculate new mtrace mtrace lenght with extra response */
+	/* ...insert new response block... */
+
+	/* calculate new mtrace lenght with extra response */
 	mtrace_len = igmp_msg_len + sizeof(struct igmp_mtrace_rsp);
 
 	/* copy received query/request */
@@ -643,84 +766,86 @@ int igmp_mtrace_recv_qry_req(struct igmp_sock *igmp, struct ip *ip_hdr,
 	/* initialize extra response field */
 	mtrace_rsp_init(rspp);
 
+	/* carry over any error noted when receiving the query */
+	rspp->fwd_code = fwd_code;
+
+	/* ...and fill in Query Arrival Time... */
 	rspp->arrival = htonl(query_arrival_time());
 	rspp->outgoing = pim_ifp->primary_address;
 	rspp->out_count = htonl(MTRACE_UNKNOWN_COUNT);
+	rspp->fwd_ttl = 1;
 
-	/* 6.2.2. 2. Attempt to determine forwarding information */
+	/* 6.2.2. 2. Attempt to determine the forwarding information... */
 
-	nh_addr.s_addr = 0;
+	if (mtracep->grp_addr.s_addr)
-
+		fwd_info = mtrace_fwd_info(pim, mtracep, rspp, &out_ifp);
-	memset(&nexthop, 0, sizeof(nexthop));
-	ret = pim_nexthop_lookup(pim, &nexthop, mtracep->src_addr, 1);
-
-	if (ret == 0) {
-		char nexthop_str[INET_ADDRSTRLEN];
-
-		if (PIM_DEBUG_MTRACE)
-			zlog_debug("mtrace pim_nexthop_lookup OK");
-
-		if (PIM_DEBUG_MTRACE)
-			zlog_warn("mtrace next_hop=%s",
-				  inet_ntop(nexthop.mrib_nexthop_addr.family,
-					    &nexthop.mrib_nexthop_addr.u.prefix,
-					    nexthop_str, sizeof(nexthop_str)));
-
-		if (nexthop.mrib_nexthop_addr.family == AF_INET)
-			nh_addr = nexthop.mrib_nexthop_addr.u.prefix4;
-	}
-	/* 6.4 Forwarding Traceroute Requests: ... Otherwise, ... */
-	else {
-		if (PIM_DEBUG_MTRACE)
-			zlog_debug("mtrace not found neighbor");
-		if (!fwd_code)
-			rspp->fwd_code = MTRACE_FWD_CODE_NO_ROUTE;
 	else
-			rspp->fwd_code = fwd_code;
+		fwd_info = mtrace_fwd_info_weak(pim, mtracep, rspp, &out_ifp);
-		/* 6.5 Sending Traceroute Responses */
+
+	/* 6.2.2 3. If no forwarding information... */
+	if (!fwd_info) {
+		if (PIM_DEBUG_MTRACE)
+			zlog_debug("mtrace not found multicast state");
+		mtrace_rsp_set_fwd_code(rspp, MTRACE_FWD_CODE_NO_ROUTE);
+		/* 6.2.2. 3. forward the packet to requester */
 		return mtrace_send_response(pim, mtracep, mtrace_len);
 	}
 
-	out_ifp = nexthop.interface;
+	nh_addr = rspp->prev_hop;
 
-	rspp->incoming = mtrace_primary_address(out_ifp);
+	reached_source = false;
-	rspp->prev_hop = nh_addr;
-	rspp->in_count = htonl(MTRACE_UNKNOWN_COUNT);
-	rspp->total = htonl(MTRACE_UNKNOWN_COUNT);
-	rspp->rtg_proto = MTRACE_RTG_PROTO_PIM;
-	rspp->fwd_ttl = 1;
-	rspp->s = 1;
-	rspp->src_mask = 32;
 
 	if (nh_addr.s_addr == 0) {
-		/* no pim? */
+		/* no pim? i.e. 7.5.3. No Previous Hop */
 		if (!out_ifp->info) {
-			rspp->fwd_code = MTRACE_FWD_CODE_NO_MULTICAST;
+			if (PIM_DEBUG_MTRACE)
+				zlog_debug("mtrace not found incoming if w/ pim");
+			mtrace_rsp_set_fwd_code(rspp,
+						MTRACE_FWD_CODE_NO_MULTICAST);
 			return mtrace_send_response(pim, mtracep, mtrace_len);
 		}
-		/* reached source? */
+		/* reached source? i.e. 7.5.1 Arriving at source */
 		if (pim_if_connected_to_source(out_ifp, mtracep->src_addr)) {
+			reached_source = true;
 			rspp->prev_hop = mtracep->src_addr;
-			return mtrace_send_response(pim, mtracep, mtrace_len);
 		}
 		/*
 		 * 6.4 Forwarding Traceroute Requests:
-		 * Previous-hop router not known
+		 * Previous-hop router not known,
+		 * packet is sent to an appropriate multicast address
 		 */
 		inet_aton(MCAST_ALL_ROUTERS, &nh_addr);
 	}
 
+	/* 6.2.2 8. If this router is the Rendez-vous Point */
+	if (pim_rp_i_am_rp(pim, mtracep->grp_addr)) {
+		mtrace_rsp_set_fwd_code(rspp, MTRACE_FWD_CODE_REACHED_RP);
+		/* 7.7.1. PIM-SM ...RP has not performed source-specific join */
+		if (rspp->src_mask == MTRACE_SRC_MASK_GROUP)
+			return mtrace_send_response(pim, mtracep, mtrace_len);
+	}
+
+	/*
+	 * 6.4 Forwarding Traceroute Requests: the number of response
+	 * blocks exceeds number of responses, so forward to the requester.
+	 */
 	if (mtracep->hops <= (last_rsp_ind + 1))
 		return mtrace_send_response(pim, mtracep, mtrace_len);
 
+	/* 7.5.1. Arriving at source: terminate trace */
+	if (reached_source)
+		return mtrace_send_response(pim, mtracep, mtrace_len);
+
 	mtracep->checksum = 0;
 
 	mtracep->checksum = in_cksum(mtrace_buf, mtrace_len);
 
+	/* 6.4 Forwarding Traceroute Requests: response blocks less than req. */
 	return mtrace_send_packet(out_ifp, mtracep, mtrace_len, nh_addr,
 				  mtracep->grp_addr);
 }
 
+/* 6.3. Traceroute responses */
 int igmp_mtrace_recv_response(struct igmp_sock *igmp, struct ip *ip_hdr,
 			      struct in_addr from, const char *from_str,
 			      char *igmp_msg, int igmp_msg_len)

pimd/pim_igmp_mtrace.h

@@ -26,6 +26,8 @@
 
 #define MTRACE_MAX_HOPS (255)
 #define MTRACE_UNKNOWN_COUNT (0xffffffff)
+#define MTRACE_SRC_MASK_GROUP (0x3f) /* forwarding on group state (*,G) */
+#define MTRACE_SRC_MASK_SOURCE (0x20) /* i.e. 32 forwarding on (S,G) */
 
 enum mtrace_fwd_code {
 	MTRACE_FWD_CODE_NO_ERROR = 0x00,

vtysh/vtysh.c

@@ -2793,14 +2793,15 @@ ALIAS(vtysh_traceroute, vtysh_traceroute_ip_cmd, "traceroute ip WORD",
 
 DEFUN (vtysh_mtrace,
        vtysh_mtrace_cmd,
-       "mtrace WORD",
+       "mtrace WORD [WORD]",
        "Multicast trace route to multicast source\n"
-       "Multicast trace route to multicast source address\n")
+       "Multicast trace route to multicast source address\n"
+       "Multicast trace route for multicast group address\n")
 {
-	int idx = 1;
+	if (argc == 2)
-
+		execute_command("mtracebis", 1, argv[1]->arg, NULL);
-	argv_find(argv, argc, "WORD", &idx);
+	else
-	execute_command("mtracebis", 1, argv[idx]->arg, NULL);
+		execute_command("mtracebis", 2, argv[1]->arg, argv[2]->arg);
 	return CMD_SUCCESS;
 }