Merge pull request #1749 from msablic/pim_mtrace_cc

pimd: Multicast traceroute client and router

1 files changed, 371 insertions, 0 deletions

diff --git a/pimd/mtracebis.c b/pimd/mtracebis.c
new file mode 100644
index 0000000000..2032cdcfbe
--- /dev/null
+++ b/pimd/mtracebis.c
@@ -0,0 +1,371 @@
+/*
+ * Multicast Traceroute for FRRouting
+ * Copyright (C) 2018  Mladen Sablic
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifdef __linux__
+
+#include "pim_igmp_mtrace.h"
+
+#include "checksum.h"
+#include "mtracebis_routeget.h"
+
+#include <sys/select.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <net/if.h>
+
+#define MTRACEBIS_VERSION "0.1"
+#define MTRACE_TIMEOUT (5)
+
+#define IP_HDR_LEN (sizeof(struct ip))
+#define IP_RA_LEN (4)
+#define MTRACE_BUF_LEN (MTRACE_HDR_SIZE + (MTRACE_MAX_HOPS * MTRACE_RSP_SIZE))
+#define IP_AND_MTRACE_BUF_LEN (IP_HDR_LEN + IP_RA_LEN + MTRACE_BUF_LEN)
+
+static const char *progname;
+static void usage(void)
+{
+	fprintf(stderr, "Usage : %s <multicast source>\n", progname);
+}
+static void version(void)
+{
+	fprintf(stderr, "%s %s\n", progname, MTRACEBIS_VERSION);
+}
+
+static int send_query(int fd, struct in_addr to_addr,
+		      struct igmp_mtrace *mtrace)
+{
+	struct sockaddr_in to;
+	socklen_t tolen;
+	int sent;
+
+	memset(&to, 0, sizeof(to));
+	to.sin_family = AF_INET;
+	to.sin_addr = to_addr;
+	tolen = sizeof(to);
+
+	sent = sendto(fd, (char *)mtrace, sizeof(*mtrace), MSG_DONTWAIT,
+		      (struct sockaddr *)&to, tolen);
+
+	if (sent < 1)
+		return -1;
+	return 0;
+}
+
+static void print_query(struct igmp_mtrace *mtrace)
+{
+	char src_str[INET_ADDRSTRLEN];
+	char dst_str[INET_ADDRSTRLEN];
+	char grp_str[INET_ADDRSTRLEN];
+
+	printf("* Mtrace from %s to %s via group %s\n",
+	       inet_ntop(AF_INET, &mtrace->src_addr, src_str, sizeof(src_str)),
+	       inet_ntop(AF_INET, &mtrace->dst_addr, dst_str, sizeof(dst_str)),
+	       inet_ntop(AF_INET, &mtrace->grp_addr, grp_str, sizeof(grp_str)));
+}
+
+static int recv_response(int fd, long msec, int *hops)
+{
+	int recvd;
+	char mtrace_buf[IP_AND_MTRACE_BUF_LEN];
+	struct ip *ip;
+	struct igmp_mtrace *mtrace;
+	int mtrace_len;
+	int responses;
+	int i;
+	u_short sum;
+
+	recvd = recvfrom(fd, mtrace_buf, IP_AND_MTRACE_BUF_LEN, 0, NULL, 0);
+
+	if (recvd < 1) {
+		fprintf(stderr, "recvfrom error: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (recvd < (int)sizeof(struct ip)) {
+		fprintf(stderr, "no ip header\n");
+		return -1;
+	}
+
+	ip = (struct ip *)mtrace_buf;
+
+	if (ip->ip_v != 4) {
+		fprintf(stderr, "IP not version 4\n");
+		return -1;
+	}
+
+	sum = ip->ip_sum;
+	ip->ip_sum = 0;
+
+	if (sum != in_cksum(ip, ip->ip_hl * 4))
+		return -1;
+
+	mtrace = (struct igmp_mtrace *)(mtrace_buf + (4 * ip->ip_hl));
+
+	mtrace_len = ntohs(ip->ip_len) - ip->ip_hl * 4;
+
+	if (mtrace_len < (int)MTRACE_HDR_SIZE)
+		return -1;
+
+	sum = mtrace->checksum;
+	mtrace->checksum = 0;
+	if (sum != in_cksum(mtrace, mtrace_len)) {
+		fprintf(stderr, "mtrace checksum wrong\n");
+		return -1;
+	}
+
+	if (mtrace->type != PIM_IGMP_MTRACE_RESPONSE)
+		return -1;
+
+
+	responses = mtrace_len - sizeof(struct igmp_mtrace);
+	responses /= sizeof(struct igmp_mtrace_rsp);
+
+	printf("%ld ms received responses from %d hops.\n", msec, responses);
+
+	if (hops)
+		*hops = responses;
+
+	for (i = 0; i < responses; i++) {
+		struct igmp_mtrace_rsp *rsp = &mtrace->rsp[i];
+
+		if (rsp->fwd_code != 0)
+			printf("-%d fwd. code 0x%2x.\n", i, rsp->fwd_code);
+	}
+
+	return 0;
+}
+
+static int wait_for_response(int fd, int *hops)
+{
+	fd_set readfds;
+	struct timeval timeout;
+	int ret = -1;
+	long msec, rmsec, tmsec;
+
+	FD_ZERO(&readfds);
+	FD_SET(fd, &readfds);
+
+	memset(&timeout, 0, sizeof(timeout));
+
+	timeout.tv_sec = MTRACE_TIMEOUT;
+
+	tmsec = timeout.tv_sec * 1000 + timeout.tv_usec / 1000;
+	do {
+		ret = select(fd + 1, &readfds, NULL, NULL, &timeout);
+		if (ret <= 0)
+			return ret;
+		rmsec = timeout.tv_sec * 1000 + timeout.tv_usec / 1000;
+		msec = tmsec - rmsec;
+	} while (recv_response(fd, msec, hops) != 0);
+
+	return ret;
+}
+
+int main(int argc, char *const argv[])
+{
+	struct in_addr mc_source;
+	struct in_addr iface_addr;
+	struct in_addr gw_addr;
+	struct in_addr mtrace_addr;
+	struct igmp_mtrace mtrace;
+	int hops = 255;
+	int rhops;
+	int maxhops = 255;
+	int perhop = 3;
+	int ifindex;
+	int unicast = 1;
+	int ttl = 64;
+	int fd = -1;
+	int ret = -1;
+	int c;
+	int i, j;
+	char ifname[IF_NAMESIZE];
+	char ip_str[INET_ADDRSTRLEN];
+
+	mtrace_addr.s_addr = inet_addr("224.0.1.32");
+
+	uid_t uid = getuid();
+
+	if (uid != 0) {
+		printf("must run as root\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (argc <= 0)
+		progname = "mtracebis";
+	else
+		progname = argv[0];
+
+	if (argc != 2) {
+		usage();
+		exit(EXIT_FAILURE);
+	}
+
+	while (1) {
+		static struct option long_options[] = {
+			{"help", no_argument, 0, 'h'},
+			{"version", no_argument, 0, 'v'},
+			{0, 0, 0, 0} };
+		int option_index = 0;
+
+		c = getopt_long(argc, argv, "vh", long_options, &option_index);
+
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h':
+			usage();
+			exit(0);
+		case 'v':
+			version();
+			exit(0);
+		default:
+			usage();
+			exit(EXIT_FAILURE);
+		}
+	}
+	if (inet_pton(AF_INET, argv[1], &mc_source) != 1) {
+		usage();
+		fprintf(stderr, "%s: %s not a valid IPv4 address\n", argv[0],
+			argv[1]);
+		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",
+			argv[0], argv[1]);
+		exit(EXIT_FAILURE);
+	}
+
+	if (if_indextoname(ifindex, ifname) == NULL) {
+		fprintf(stderr, "%s: if_indextoname error: %s\n", argv[0],
+			strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	/* zero mtrace struct */
+	memset((char *)&mtrace, 0, sizeof(mtrace));
+
+	/* set up query */
+	mtrace.type = PIM_IGMP_MTRACE_QUERY_REQUEST;
+	mtrace.hops = hops;
+	mtrace.checksum = 0;
+	mtrace.grp_addr.s_addr = 0;
+	mtrace.src_addr = mc_source;
+	mtrace.dst_addr = iface_addr;
+	mtrace.rsp_addr = unicast ? iface_addr : mtrace_addr;
+	mtrace.rsp_ttl = ttl;
+	mtrace.qry_id = 0xffffff & time(NULL);
+
+	mtrace.checksum = in_cksum(&mtrace, sizeof(mtrace));
+
+	fd = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP);
+
+	if (fd < 1) {
+		fprintf(stderr, "%s: socket error: %s\n", argv[0],
+			strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	ret = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, ifname,
+			 strlen(ifname));
+
+	if (ret < 0) {
+		fprintf(stderr, "%s: setsockopt error: %s\n", argv[0],
+			strerror(errno));
+		ret = EXIT_FAILURE;
+		goto close_fd;
+	}
+
+	print_query(&mtrace);
+	if (send_query(fd, gw_addr, &mtrace) < 0) {
+		fprintf(stderr, "%s: sendto error: %s\n", argv[0],
+			strerror(errno));
+		ret = EXIT_FAILURE;
+		goto close_fd;
+	}
+	printf("Querying full reverse path...\n");
+	ret = wait_for_response(fd, NULL);
+	if (ret > 0) {
+		ret = 0;
+		goto close_fd;
+	}
+	if (ret < 0) {
+		fprintf(stderr, "%s: select error: %s\n", argv[0],
+			strerror(errno));
+		ret = EXIT_FAILURE;
+		goto close_fd;
+	}
+	printf(" * ");
+	printf("switching to hop-by-hop:\n");
+	printf("%3d  ? (%s)\n", 0,
+	       inet_ntop(AF_INET, &mtrace.dst_addr, ip_str, sizeof(ip_str)));
+	for (i = 1; i < maxhops; i++) {
+		printf("%3d ", -i);
+		mtrace.hops = i;
+		for (j = 0; j < perhop; j++) {
+			mtrace.qry_id++;
+			mtrace.checksum = 0;
+			mtrace.checksum = in_cksum(&mtrace, sizeof(mtrace));
+			if (send_query(fd, gw_addr, &mtrace) < 0) {
+				fprintf(stderr, "%s: sendto error: %s\n",
+					argv[0], strerror(errno));
+				ret = EXIT_FAILURE;
+				goto close_fd;
+			}
+			ret = wait_for_response(fd, &rhops);
+			if (ret > 0) {
+				if (i > rhops) {
+					ret = 0;
+					goto close_fd;
+				}
+				break;
+			}
+			printf(" *");
+		}
+		if (ret <= 0)
+			printf("\n");
+	}
+	ret = 0;
+close_fd:
+	close(fd);
+	exit(ret);
+}
+
+#else /* __linux__ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[])
+{
+	printf("%s implemented only for GNU/Linux\n", argv[0]);
+	exit(0);
+}
+
+#endif /* __linux__ */