radvdump.c

/*
 *
 *   Authors:
 *    Lars Fenneberg		<lf@elemental.net>
 *    Marko Myllynen		<myllynen@lut.fi>
 *
 *   This software is Copyright 1996-2000 by the above mentioned author(s),
 *   All Rights Reserved.
 *
 *   The license which is distributed with this software in the file COPYRIGHT
 *   applies to this software. If your distribution is missing this file, you
 *   may request it from <reubenhwk@gmail.com>.
 *
 */

#include "config.h"
#include "includes.h"
#include "radvd.h"

static char usage_str[] = "[-vhfe] [-d level]";

#ifdef HAVE_GETOPT_LONG
struct option prog_opt[] = {
	{"debug", 1, 0, 'd'},
	{"file-format", 0, 0, 'f'},
	{"exclude-defaults", 0, 0, 'e'},
	{"version", 0, 0, 'v'},
	{"help", 0, 0, 'h'},
	{NULL, 0, 0, 0}
};
#endif

int sock = -1;

static void version(void);
static void usage(char const * pname);
static void print_ff(unsigned char *, int, struct sockaddr_in6 *, int, unsigned int, int);
static void print_preferences(int);

int main(int argc, char *argv[])
{
	int c;
	int edefs = 0;
#ifdef HAVE_GETOPT_LONG
	int opt_idx;
#endif
	char const * pname = ((pname = strrchr(argv[0], '/')) != NULL) ? pname + 1 : argv[0];

	/* parse args */
#ifdef HAVE_GETOPT_LONG
	while ((c = getopt_long(argc, argv, "d:fehv", prog_opt, &opt_idx)) > 0)
#else
	while ((c = getopt(argc, argv, "d:fehv")) > 0)
#endif
	{
		switch (c) {
		case 'd':
			set_debuglevel(atoi(optarg));
			break;
		case 'f':
			break;
		case 'e':
			edefs = 1;
			break;
		case 'v':
			version();
			break;
		case 'h':
			usage(pname);
#ifdef HAVE_GETOPT_LONG
		case ':':
			fprintf(stderr, "%s: option %s: parameter expected\n", pname, prog_opt[opt_idx].name);
			exit(1);
#endif
		case '?':
			exit(1);
		}
	}

	if (log_open(L_STDERR, pname, NULL, 0) < 0) {
		perror("log_open");
		exit(1);
	}

	/* get a raw socket for sending and receiving ICMPv6 messages */
	int sock = open_icmpv6_socket();
	if (sock < 0) {
		perror("open_icmpv6_socket");
		exit(1);
	}

	for (;;) {
		unsigned char msg[MSG_SIZE_RECV];
		int hoplimit = 0;
		struct in6_pktinfo *pkt_info = NULL;
		struct sockaddr_in6 rcv_addr;
		unsigned char chdr[CMSG_SPACE(sizeof(struct in6_pktinfo)) + CMSG_SPACE(sizeof(int))];
		int len = recv_rs_ra(sock, msg, &rcv_addr, &pkt_info, &hoplimit, chdr);
		if (len > 0) {
			struct icmp6_hdr *icmph;

			/*
			 * can this happen?
			 */

			if (len < sizeof(struct icmp6_hdr)) {
				flog(LOG_WARNING, "received icmpv6 packet with invalid length: %d", len);
				exit(1);
			}

			icmph = (struct icmp6_hdr *)msg;

			if (icmph->icmp6_type != ND_ROUTER_SOLICIT && icmph->icmp6_type != ND_ROUTER_ADVERT) {
				/*
				 *      We just want to listen to RSs and RAs
				 */

				flog(LOG_ERR, "icmpv6 filter failed");
				exit(1);
			}

			dlog(LOG_DEBUG, 4, "receiver if_index: %u", pkt_info->ipi6_ifindex);

			if (icmph->icmp6_type == ND_ROUTER_SOLICIT) {
				/* not yet */
			} else if (icmph->icmp6_type == ND_ROUTER_ADVERT)
				print_ff(msg, len, &rcv_addr, hoplimit, (unsigned int)pkt_info->ipi6_ifindex, edefs);
		} else if (len == 0) {
			flog(LOG_ERR, "received zero lenght packet");
			exit(1);
		} else {
			flog(LOG_ERR, "recv_rs_ra: %s", strerror(errno));
			exit(1);
		}
	}

	exit(0);
}

static void print_ff(unsigned char *msg, int len, struct sockaddr_in6 *addr, int hoplimit, unsigned int if_index, int edefs)
{
	/* XXX: hoplimit not being used for anything here.. */
	int orig_len = len;

	char addr_str[INET6_ADDRSTRLEN];
	addrtostr(&addr->sin6_addr, addr_str, sizeof(addr_str));
	printf("#\n# radvd configuration generated by radvdump %s\n", VERSION);
	printf("# based on Router Advertisement from %s\n", addr_str);
	char if_name[IFNAMSIZ] = { "" };
	if_indextoname(if_index, if_name);
	printf("# received by interface %s\n", if_name);
	printf("#\n\ninterface %s\n{\n\tAdvSendAdvert on;\n", if_name);

	printf("\t# Note: {Min,Max}RtrAdvInterval cannot be obtained with radvdump\n");

	struct nd_router_advert *radvert = (struct nd_router_advert *)msg;

	if (!edefs || DFLT_AdvManagedFlag != (ND_RA_FLAG_MANAGED == (radvert->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED)))
		printf("\tAdvManagedFlag %s;\n", (radvert->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) ? "on" : "off");

	if (!edefs || DFLT_AdvOtherConfigFlag != (ND_RA_FLAG_OTHER == (radvert->nd_ra_flags_reserved & ND_RA_FLAG_OTHER)))
		printf("\tAdvOtherConfigFlag %s;\n", (radvert->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) ? "on" : "off");

	if (!edefs || DFLT_AdvReachableTime != ntohl(radvert->nd_ra_reachable))
		printf("\tAdvReachableTime %u;\n", ntohl(radvert->nd_ra_reachable));

	if (!edefs || DFLT_AdvRetransTimer != ntohl(radvert->nd_ra_retransmit))
		printf("\tAdvRetransTimer %u;\n", ntohl(radvert->nd_ra_retransmit));

	if (!edefs || DFLT_AdvCurHopLimit != radvert->nd_ra_curhoplimit)
		printf("\tAdvCurHopLimit %u;\n", radvert->nd_ra_curhoplimit);

	if (!edefs || (3 * DFLT_MaxRtrAdvInterval) != ntohs(radvert->nd_ra_router_lifetime))
		printf("\tAdvDefaultLifetime %hu;\n", ntohs(radvert->nd_ra_router_lifetime));

	/* Mobile IPv6 ext */
	if (!edefs
	    || DFLT_AdvHomeAgentFlag != (ND_RA_FLAG_HOME_AGENT == (radvert->nd_ra_flags_reserved & ND_RA_FLAG_HOME_AGENT)))
		printf("\tAdvHomeAgentFlag %s;\n", (radvert->nd_ra_flags_reserved & ND_RA_FLAG_HOME_AGENT) ? "on" : "off");

	/* Route Preferences and more specific routes */
	/* XXX two middlemost bits from 8 bit field */
	if (!edefs || (((radvert->nd_ra_flags_reserved & 0x18) >> 3) & 0xff) != DFLT_AdvDefaultPreference) {
		printf("\tAdvDefaultPreference ");
		print_preferences(((radvert->nd_ra_flags_reserved & 0x18) >> 3) & 0xff);
		printf(";\n");
	}

	len -= sizeof(struct nd_router_advert);

	if (len == 0)
		return;

	uint8_t *opt_str = (uint8_t *) (msg + sizeof(struct nd_router_advert));

	while (len > 0) {

		if (len < 2) {
			flog(LOG_ERR, "trailing garbage in RA from %s", addr_str);
			break;
		}

		int optlen = (opt_str[1] << 3);

		if (optlen == 0) {
			flog(LOG_ERR, "zero length option in RA");
			break;
		} else if (optlen > len) {
			flog(LOG_ERR, "option length greater than total" " length in RA (type %d, optlen %d, len %d)",
			     (int)*opt_str, optlen, len);
			break;
		}

		switch (*opt_str) {
		case ND_OPT_MTU:{
				struct nd_opt_mtu *mtu = (struct nd_opt_mtu *)opt_str;

				if (!edefs || DFLT_AdvLinkMTU != ntohl(mtu->nd_opt_mtu_mtu))
					printf("\tAdvLinkMTU %u;\n", ntohl(mtu->nd_opt_mtu_mtu));
				break;
			}
		case ND_OPT_SOURCE_LINKADDR:
			/* XXX: !DFLT depends on current DFLT_ value */
			if (!edefs || !DFLT_AdvSourceLLAddress)
				printf("\tAdvSourceLLAddress on;\n");
			break;
			/* Mobile IPv6 ext */
		case ND_OPT_RTR_ADV_INTERVAL:
			/* XXX: !DFLT depends on current DFLT_ value */
			if (!edefs || !DFLT_AdvIntervalOpt)
				printf("\tAdvIntervalOpt on;\n");
			break;
			/* Mobile IPv6 ext */
		case ND_OPT_HOME_AGENT_INFO:{
				struct HomeAgentInfo *ha_info = (struct HomeAgentInfo *)opt_str;

				/* XXX: we check DFLT_HomeAgentInfo by interface, and it's outside
				   of context here, so we always need to print it out.. */
				printf("\tAdvHomeAgentInfo on;\n");

				/* NEMO ext */
				if (!edefs
				    || DFLT_AdvMobRtrSupportFlag != (ha_info->flags_reserved & ND_OPT_HAI_FLAG_SUPPORT_MR))
					printf("\tAdvMobRtrSupportFlag %s;\n",
					       (ha_info->flags_reserved & ND_OPT_HAI_FLAG_SUPPORT_MR) ? "on" : "off");

				if (!edefs || DFLT_HomeAgentPreference != ntohs(ha_info->preference))
					printf("\tHomeAgentPreference %hu;\n", ntohs(ha_info->preference));
				/* Hum.. */
				if (!edefs || (3 * DFLT_MaxRtrAdvInterval) != ntohs(ha_info->lifetime))
					printf("\tHomeAgentLifetime %hu;\n", ntohs(ha_info->lifetime));
				break;
			}
		case ND_OPT_TARGET_LINKADDR:
		case ND_OPT_REDIRECTED_HEADER:
			flog(LOG_ERR, "invalid option %d in RA", (int)*opt_str);
			break;
		case ND_OPT_PREFIX_INFORMATION:
			break;
		case ND_OPT_ROUTE_INFORMATION:
			break;
		case ND_OPT_RDNSS_INFORMATION:
			break;
		case ND_OPT_DNSSL_INFORMATION:
			break;
		default:
			dlog(LOG_DEBUG, 1, "unknown option %d in RA", (int)*opt_str);
			break;
		}

		len -= optlen;
		opt_str += optlen;
	}

	orig_len -= sizeof(struct nd_router_advert);

	if (orig_len == 0)
		return;

	opt_str = (uint8_t *) (msg + sizeof(struct nd_router_advert));

	while (orig_len > 0) {
		char prefix_str[INET6_ADDRSTRLEN];

		if (orig_len < 2) {
			flog(LOG_ERR, "trailing garbage in RA from %s", addr_str);
			break;
		}

		int optlen = (opt_str[1] << 3);

		if (optlen == 0) {
			flog(LOG_ERR, "zero length option in RA");
			break;
		} else if (optlen > orig_len) {
			flog(LOG_ERR, "option length greater than total" " length in RA (type %d, optlen %d, len %d)",
			     (int)*opt_str, optlen, orig_len);
			break;
		}

		switch (*opt_str) {
		case ND_OPT_PREFIX_INFORMATION:{
				struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info *)opt_str;

				addrtostr(&pinfo->nd_opt_pi_prefix, prefix_str, sizeof(prefix_str));

				printf("\n\tprefix %s/%d\n\t{\n", prefix_str, pinfo->nd_opt_pi_prefix_len);

				if (ntohl(pinfo->nd_opt_pi_valid_time) == 0xffffffff) {
					if (!edefs || DFLT_AdvValidLifetime != 0xffffffff)
						printf("\t\tAdvValidLifetime infinity; # (0xffffffff)\n");
				} else {
					if (!edefs || DFLT_AdvValidLifetime != ntohl(pinfo->nd_opt_pi_valid_time))
						printf("\t\tAdvValidLifetime %u;\n", ntohl(pinfo->nd_opt_pi_valid_time));
				}
				if (ntohl(pinfo->nd_opt_pi_preferred_time) == 0xffffffff) {
					if (!edefs || DFLT_AdvPreferredLifetime != 0xffffffff)
						printf("\t\tAdvPreferredLifetime infinity; # (0xffffffff)\n");
				} else {
					if (!edefs || DFLT_AdvPreferredLifetime != ntohl(pinfo->nd_opt_pi_preferred_time))
						printf("\t\tAdvPreferredLifetime %u;\n",
						       ntohl(pinfo->nd_opt_pi_preferred_time));
				}

				if (!edefs
				    || DFLT_AdvOnLinkFlag != (ND_OPT_PI_FLAG_ONLINK ==
							      (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK)))
					printf("\t\tAdvOnLink %s;\n",
					       (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) ? "on" : "off");

				if (!edefs
				    || DFLT_AdvAutonomousFlag != (ND_OPT_PI_FLAG_AUTO ==
								  (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO)))
					printf("\t\tAdvAutonomous %s;\n",
					       (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) ? "on" : "off");

				/* Mobile IPv6 ext */
				if (!edefs
				    || DFLT_AdvRouterAddr != (ND_OPT_PI_FLAG_RADDR ==
							      (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_RADDR)))
					printf("\t\tAdvRouterAddr %s;\n",
					       (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_RADDR) ? "on" : "off");

				printf("\t}; # End of prefix definition\n\n");
				break;
			}
		case ND_OPT_ROUTE_INFORMATION:{
				struct nd_opt_route_info_local *rinfo = (struct nd_opt_route_info_local *)opt_str;

				if (optlen == 8) {
					printf("\n\troute ::/0\n\t{\n");
				} else {
					struct in6_addr addr;
					memset(&addr, 0, sizeof(addr));
					if (rinfo->nd_opt_ri_len > 1)
						memcpy(&addr, &rinfo->nd_opt_ri_prefix, (rinfo->nd_opt_ri_len - 1) * 8);
					addrtostr(&addr, prefix_str, sizeof(prefix_str));
					printf("\n\troute %s/%d\n\t{\n", prefix_str, rinfo->nd_opt_ri_prefix_len);
				}

				if (!edefs
				    || (((radvert->nd_ra_flags_reserved & 0x18) >> 3) & 0xff) != DFLT_AdvRoutePreference) {
					printf("\t\tAdvRoutePreference ");
					print_preferences(((rinfo->nd_opt_ri_flags_reserved & 0x18) >> 3) & 0xff);
					printf(";\n");
				}

				/* XXX: we check DFLT_AdvRouteLifetime by interface, and it's outside of context here */
				if (ntohl(rinfo->nd_opt_ri_lifetime) == 0xffffffff)
					printf("\t\tAdvRouteLifetime infinity; # (0xffffffff)\n");
				else
					printf("\t\tAdvRouteLifetime %u;\n", ntohl(rinfo->nd_opt_ri_lifetime));

				printf("\t}; # End of route definition\n\n");
				break;
			}
		case ND_OPT_RDNSS_INFORMATION:{
				struct nd_opt_rdnss_info_local *rdnss_info = (struct nd_opt_rdnss_info_local *)opt_str;

				printf("\n\tRDNSS");

				addrtostr(&rdnss_info->nd_opt_rdnssi_addr1, prefix_str, sizeof(prefix_str));
				printf(" %s", prefix_str);

				if (rdnss_info->nd_opt_rdnssi_len >= 5) {
					addrtostr(&rdnss_info->nd_opt_rdnssi_addr2, prefix_str, sizeof(prefix_str));
					printf(" %s", prefix_str);
				}
				if (rdnss_info->nd_opt_rdnssi_len >= 7) {
					addrtostr(&rdnss_info->nd_opt_rdnssi_addr3, prefix_str, sizeof(prefix_str));
					printf(" %s", prefix_str);
				}

				printf("\n\t{\n");
				/* as AdvRDNSSLifetime may depend on MaxRtrAdvInterval, it could change */
				if (ntohl(rdnss_info->nd_opt_rdnssi_lifetime) == 0xffffffff)
					printf("\t\tAdvRDNSSLifetime infinity; # (0xffffffff)\n");
				else
					printf("\t\tAdvRDNSSLifetime %u;\n", ntohl(rdnss_info->nd_opt_rdnssi_lifetime));

				printf("\t}; # End of RDNSS definition\n\n");
				break;
			}
		case ND_OPT_DNSSL_INFORMATION:{
				struct nd_opt_dnssl_info_local *dnssl_info = (struct nd_opt_dnssl_info_local *)opt_str;

				printf("\n\tDNSSL");

				char suffix[256] = { "" };
				for (int offset = 0; offset < (dnssl_info->nd_opt_dnssli_len - 1) * 8;) {
					int label_len = dnssl_info->nd_opt_dnssli_suffixes[offset++];

					if (label_len == 0) {
						/*
						 * Ignore empty suffixes. They're
						 * probably just padding...
						 */
						if (suffix[0] == '\0')
							continue;

						printf(" %s", suffix);

						suffix[0] = '\0';
						continue;
					}

					if ((sizeof(suffix) - strlen(suffix)) < (label_len + 2)) {
						flog(LOG_ERR, "oversized suffix in DNSSL option from %s", addr_str);
						break;
					}

					if (suffix[0] != '\0')
						strcat(suffix, ".");
					strncat(suffix, (char *)&dnssl_info->nd_opt_dnssli_suffixes[offset], label_len);
					offset += label_len;
				}

				printf("\n\t{\n");
				/* as AdvDNSSLLifetime may depend on MaxRtrAdvInterval, it could change */
				if (ntohl(dnssl_info->nd_opt_dnssli_lifetime) == 0xffffffff)
					printf("\t\tAdvDNSSLLifetime infinity; # (0xffffffff)\n");
				else
					printf("\t\tAdvDNSSLLifetime %u;\n", ntohl(dnssl_info->nd_opt_dnssli_lifetime));

				printf("\t}; # End of DNSSL definition\n\n");
				break;
			}
		default:
			break;
		}
		orig_len -= optlen;
		opt_str += optlen;
	}

	printf("}; # End of interface definition\n");

	fflush(stdout);
}

static void print_preferences(int p)
{
	switch (p) {
	case 0:
		printf("medium");
		break;
	case 1:
		printf("high");
		break;
	case 2:
		/* reserved, ignore */
		break;
	case 3:
		printf("low");
		break;
	}
}

static void version(void)
{
	fprintf(stderr, "Version: %s\n\n", VERSION);
	fprintf(stderr, "Please send bug reports and suggestions to %s\n", CONTACT_EMAIL);
	exit(-1);
}

static void usage(char const * pname)
{
	fprintf(stderr, "usage: %s %s\n", pname, usage_str);
	exit(-1);
}