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-rw-r--r--pimd/mtracebis.c590
1 files changed, 590 insertions, 0 deletions
diff --git a/pimd/mtracebis.c b/pimd/mtracebis.c
new file mode 100644
index 0000000..3b69964
--- /dev/null
+++ b/pimd/mtracebis.c
@@ -0,0 +1,590 @@
+/*
+ * 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
+ */
+
+#include <zebra.h>
+
+#ifdef __linux__
+
+#include "pim_igmp_mtrace.h"
+
+#include "checksum.h"
+#include "prefix.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>
+#include <unistd.h>
+#include <getopt.h>
+#include <netdb.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> [<multicast group>]\n",
+ progname);
+}
+static void version(void)
+{
+ fprintf(stderr, "%s %s\n", progname, MTRACEBIS_VERSION);
+}
+
+static void print_host(struct in_addr addr)
+{
+ struct hostent *h;
+ char buf[PREFIX_STRLEN];
+
+ h = gethostbyaddr(&addr, sizeof(addr), AF_INET);
+ if (h == NULL)
+ printf("?");
+ else
+ printf("%s", h->h_name);
+ printf(" (%s) ", inet_ntop(AF_INET, &addr, buf, sizeof(buf)));
+}
+
+static void print_line_no(int i)
+{
+ printf("%3d ", -i);
+}
+
+static const char *rtg_proto_str(enum mtrace_rtg_proto proto)
+{
+ static char buf[80];
+
+ buf[0] = '\0';
+
+ switch (proto) {
+ case MTRACE_RTG_PROTO_DVMRP:
+ return "DVMRP";
+ case MTRACE_RTG_PROTO_MOSPF:
+ return "MOSPF";
+ case MTRACE_RTG_PROTO_PIM:
+ return "PIM";
+ case MTRACE_RTG_PROTO_CBT:
+ return "CBT";
+ case MTRACE_RTG_PROTO_PIM_SPECIAL:
+ return "PIM special";
+ case MTRACE_RTG_PROTO_PIM_STATIC:
+ return "PIM static";
+ case MTRACE_RTG_PROTO_DVMRP_STATIC:
+ return "DVMRP static";
+ case MTRACE_RTG_PROTO_PIM_MBGP:
+ return "PIM MBGP";
+ case MTRACE_RTG_PROTO_CBT_SPECIAL:
+ return "CBT special";
+ case MTRACE_RTG_PROTO_CBT_STATIC:
+ return "CBT static";
+ case MTRACE_RTG_PROTO_PIM_ASSERT:
+ return "PIM assert";
+ default:
+ snprintf(buf, sizeof(buf), "unknown protocol (%d)", proto);
+ return buf;
+ }
+}
+
+static void print_rtg_proto(uint32_t rtg_proto)
+{
+ printf("%s", rtg_proto_str(rtg_proto));
+}
+
+static void print_fwd_ttl(uint32_t fwd_ttl)
+{
+ printf("thresh^ %d", fwd_ttl);
+}
+
+static const char *fwd_code_str(enum mtrace_fwd_code code)
+{
+ static char buf[80];
+
+ buf[0] = '\0';
+
+ switch (code) {
+ case MTRACE_FWD_CODE_NO_ERROR:
+ return "no error";
+ case MTRACE_FWD_CODE_WRONG_IF:
+ return "wrong interface";
+ case MTRACE_FWD_CODE_PRUNE_SENT:
+ return "prune sent";
+ case MTRACE_FWD_CODE_PRUNE_RCVD:
+ return "prune received";
+ case MTRACE_FWD_CODE_SCOPED:
+ return "scoped";
+ case MTRACE_FWD_CODE_NO_ROUTE:
+ return "no route";
+ case MTRACE_FWD_CODE_WRONG_LAST_HOP:
+ return "wrong last hop";
+ case MTRACE_FWD_CODE_NOT_FORWARDING:
+ return "not forwarding";
+ case MTRACE_FWD_CODE_REACHED_RP:
+ return "reached RP";
+ case MTRACE_FWD_CODE_RPF_IF:
+ return "RPF interface";
+ case MTRACE_FWD_CODE_NO_MULTICAST:
+ return "no multicast";
+ case MTRACE_FWD_CODE_INFO_HIDDEN:
+ return "info hidden";
+ case MTRACE_FWD_CODE_NO_SPACE:
+ return "no space";
+ case MTRACE_FWD_CODE_OLD_ROUTER:
+ return "old router";
+ case MTRACE_FWD_CODE_ADMIN_PROHIB:
+ return "admin. prohib.";
+ default:
+ snprintf(buf, sizeof(buf), "unknown fwd. code (%d)", code);
+ return buf;
+ }
+}
+
+static void print_fwd_code(uint32_t fwd_code)
+{
+ printf("%s", fwd_code_str(fwd_code));
+}
+
+static void print_rsp(struct igmp_mtrace_rsp *rsp)
+{
+ print_host(rsp->outgoing);
+ 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);
+ }
+ printf("\n");
+}
+
+static void print_dest(struct igmp_mtrace *mtrace)
+{
+ print_line_no(0);
+ print_host(mtrace->dst_addr);
+ printf("\n");
+}
+
+static void print_summary(struct igmp_mtrace *mtrace, int hops, long msec)
+{
+ int i;
+ int t = 0;
+
+ for (i = 0; i < hops; i++)
+ t += mtrace->rsp[i].fwd_ttl;
+
+ printf("Round trip time %ld ms; total ttl of %d required.\n", msec, t);
+}
+
+static void print_responses(struct igmp_mtrace *mtrace, int hops, long msec)
+{
+ int i;
+
+ print_dest(mtrace);
+
+ for (i = 0; i < hops; i++) {
+ print_line_no(i + 1);
+ print_rsp(&mtrace->rsp[i]);
+ }
+ print_summary(mtrace, hops, msec);
+}
+
+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, int *hops, struct igmp_mtrace *mtracer)
+{
+ int recvd;
+ char mtrace_buf[IP_AND_MTRACE_BUF_LEN];
+ struct ip *ip;
+ struct igmp_mtrace *mtrace;
+ int mtrace_len;
+ int responses;
+ unsigned short sum;
+ size_t mtrace_off;
+ size_t ip_len;
+
+ 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;
+
+ /* Header overflow check */
+ mtrace_off = 4 * ip->ip_hl;
+ if (mtrace_off > MTRACE_BUF_LEN)
+ return -1;
+
+ /* Underflow/overflow check */
+ ip_len = ntohs(ip->ip_len);
+ if (ip_len < mtrace_off || ip_len < MTRACE_HDR_SIZE
+ || ip_len > MTRACE_BUF_LEN)
+ return -1;
+
+ mtrace_len = ip_len - mtrace_off;
+ mtrace = (struct igmp_mtrace *)(mtrace_buf + mtrace_off);
+
+ 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);
+
+ if (responses > MTRACE_MAX_HOPS) {
+ fprintf(stderr, "mtrace too large\n");
+ return -1;
+ }
+
+ if (hops)
+ *hops = responses;
+
+ if (mtracer)
+ memcpy(mtracer, mtrace, mtrace_len);
+
+ return 0;
+}
+
+static int wait_for_response(int fd, int *hops, struct igmp_mtrace *mtrace,
+ long *ret_msec)
+{
+ fd_set readfds;
+ struct timeval timeout;
+ int ret;
+ 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, hops, mtrace) != 0);
+
+ if (ret_msec)
+ *ret_msec = msec;
+
+ return ret;
+}
+
+static bool check_end(struct igmp_mtrace *mtrace, int hops)
+{
+ return mtrace->src_addr.s_addr == mtrace->rsp[hops - 1].prev_hop.s_addr;
+}
+
+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;
+ struct igmp_mtrace mtrace;
+ struct igmp_mtrace *mtracep;
+ 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;
+ long msec;
+ 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");
+
+ 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 && argc != 3) {
+ 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 is not a valid IPv4 address\n", argv[0],
+ argv[1]);
+ exit(EXIT_FAILURE);
+ }
+
+ mc_group.s_addr = INADDR_ANY;
+ 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",
+ 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 = mc_group;
+ 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");
+ mtracep = (struct igmp_mtrace *)mbuf;
+ ret = wait_for_response(fd, &rhops, mtracep, &msec);
+ if (ret > 0) {
+ print_responses(mtracep, rhops, msec);
+ 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");
+ print_dest(&mtrace);
+ for (i = 1; i < maxhops; i++) {
+ print_line_no(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, mtracep, &msec);
+ if (ret > 0) {
+ if (check_end(mtracep, rhops)) {
+ print_rsp(&mtracep->rsp[rhops - 1]);
+ print_summary(mtracep, rhops, msec);
+ ret = 0;
+ goto close_fd;
+ }
+ if (i > rhops) {
+ printf(" * ...giving up.\n");
+ ret = 0;
+ goto close_fd;
+ }
+ print_rsp(&mtracep->rsp[rhops - 1]);
+ 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__ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 09:26:50 +0000