RDNSS section support more ipv6 aaddrss

RFC 6106 recommended that the number of RDNSS addresses thatshould be learned and maintained through the RDNSS RA option should be limited to three.  RFC 8106 removes that recommendation; thus, the number of RDNSS addresses to maintain is determined by an implementer's local policy.The number of RDNSS addresses to maintain is determined by the user's own profile

defaults.h

@@ -205,9 +205,7 @@ struct nd_opt_rdnss_info_local {
 	uint8_t nd_opt_rdnssi_len;
 	uint16_t nd_opt_rdnssi_pref_flag_reserved;
 	uint32_t nd_opt_rdnssi_lifetime;
-	struct in6_addr nd_opt_rdnssi_addr1;
-	struct in6_addr nd_opt_rdnssi_addr2;
-	struct in6_addr nd_opt_rdnssi_addr3;
+	struct in6_addr nd_opt_rdnssi_addr[];
 };
 /* pref/flag/reserved field : yyyyx00000000000 (big endian) - 00000000yyyyx000 (little indian); where yyyy = pref, x = flag */
 #if BYTE_ORDER == BIG_ENDIAN

gram.y

@@ -786,24 +786,15 @@ rdnssaddr	: IPV6ADDR
 				rdnss_init_defaults(rdnss, iface);
 			}
 
-			switch (rdnss->AdvRDNSSNumber) {
-				case 0:
-					memcpy(&rdnss->AdvRDNSSAddr1, $1, sizeof(struct in6_addr));
-					rdnss->AdvRDNSSNumber++;
-					break;
-				case 1:
-					memcpy(&rdnss->AdvRDNSSAddr2, $1, sizeof(struct in6_addr));
-					rdnss->AdvRDNSSNumber++;
-					break;
-				case 2:
-					memcpy(&rdnss->AdvRDNSSAddr3, $1, sizeof(struct in6_addr));
-					rdnss->AdvRDNSSNumber++;
-					break;
-				default:
-					flog(LOG_CRIT, "too many addresses in RDNSS section");
-					ABORT;
+			rdnss->AdvRDNSSNumber++;
+			rdnss->AdvRDNSSAddr =
+				realloc(rdnss->AdvRDNSSAddr,
+					rdnss->AdvRDNSSNumber * sizeof(struct in6_addr));
+			if (rdnss->AdvRDNSSAddr == NULL) {
+				flog(LOG_CRIT, "realloc failed: %s", strerror(errno));
+				ABORT;
 			}
-
+			memcpy(&rdnss->AdvRDNSSAddr[rdnss->AdvRDNSSNumber - 1], $1, sizeof(struct in6_addr));
 		}
 		;
 
@@ -1066,6 +1057,7 @@ static void cleanup(void)
 	}
 
 	if (rdnss) {
+		free(rdnss->AdvRDNSSAddr);
 		free(rdnss);
 		rdnss = 0;
 	}

interface.c

@@ -420,6 +420,7 @@ static void free_iface_list(struct Interface *iface)
 		while (rdnss) {
 			struct AdvRDNSS *next_rdnss = rdnss->next;
 
+			free(rdnss->AdvRDNSSAddr);
 			free(rdnss);
 			rdnss = next_rdnss;
 		}

process.c

@@ -322,44 +322,21 @@ static void process_ra(struct Interface *iface, unsigned char *msg, int len, str
 			break;
 		case ND_OPT_RDNSS_INFORMATION: {
 			char rdnss_str[INET6_ADDRSTRLEN];
-			struct AdvRDNSS *rdnss = 0;
 			struct nd_opt_rdnss_info_local *rdnssinfo = (struct nd_opt_rdnss_info_local *)opt_str;
 			if (len < sizeof(*rdnssinfo))
 				return;
-			int count = rdnssinfo->nd_opt_rdnssi_len;
-
-			/* Check the RNDSS addresses received */
-			switch (count) {
-			case 7:
-				rdnss = iface->AdvRDNSSList;
-				if (!check_rdnss_presence(rdnss, &rdnssinfo->nd_opt_rdnssi_addr3)) {
-					/* no match found in iface->AdvRDNSSList */
-					addrtostr(&rdnssinfo->nd_opt_rdnssi_addr3, rdnss_str, sizeof(rdnss_str));
-					flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
-					     rdnss_str, iface->props.name, addr_str);
-				}
-			/* FALLTHROUGH */
-			case 5:
-				rdnss = iface->AdvRDNSSList;
-				if (!check_rdnss_presence(rdnss, &rdnssinfo->nd_opt_rdnssi_addr2)) {
-					/* no match found in iface->AdvRDNSSList */
-					addrtostr(&rdnssinfo->nd_opt_rdnssi_addr2, rdnss_str, sizeof(rdnss_str));
-					flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
-					     rdnss_str, iface->props.name, addr_str);
-				}
-			/* FALLTHROUGH */
-			case 3:
-				rdnss = iface->AdvRDNSSList;
-				if (!check_rdnss_presence(rdnss, &rdnssinfo->nd_opt_rdnssi_addr1)) {
-					/* no match found in iface->AdvRDNSSList */
-					addrtostr(&rdnssinfo->nd_opt_rdnssi_addr1, rdnss_str, sizeof(rdnss_str));
-					flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
-					     rdnss_str, iface->props.name, addr_str);
-				}
 
-				break;
-			default:
-				flog(LOG_ERR, "invalid len %i in RDNSS option on %s from %s", count, iface->props.name, addr_str);
+			if (rdnssinfo->nd_opt_rdnssi_len > 2) {
+				for (int i = 0; i < (rdnssinfo->nd_opt_rdnssi_len - 1) / 2; i++) {
+					if (!check_rdnss_presence(iface->AdvRDNSSList, &rdnssinfo->nd_opt_rdnssi_addr[i])) {
+						addrtostr(&rdnssinfo->nd_opt_rdnssi_addr[i], rdnss_str, sizeof(rdnss_str));
+						flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
+						     rdnss_str, iface->props.name, addr_str);
+					}
+				}
+			} else {
+				flog(LOG_ERR, "invalid len %i in RDNSS option on %s from %s",
+				     rdnssinfo->nd_opt_rdnssi_len, iface->props.name, addr_str);
 			}
 
 			break;

radvd.h

@@ -198,9 +198,7 @@ struct AdvRDNSS {
 	int AdvRDNSSNumber;
 	uint32_t AdvRDNSSLifetime;
 	int FlushRDNSSFlag;
-	struct in6_addr AdvRDNSSAddr1;
-	struct in6_addr AdvRDNSSAddr2;
-	struct in6_addr AdvRDNSSAddr3;
+	struct in6_addr *AdvRDNSSAddr;
 
 	struct AdvRDNSS *next;
 };

radvdump.c

@@ -402,15 +402,8 @@ static void print_ff(unsigned char *msg, int len, struct sockaddr_in6 *addr, int
 
 			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));
+			for (int i = 0; i < (rdnss_info->nd_opt_rdnssi_len - 1) / 2; i++) {
+				addrtostr(&rdnss_info->nd_opt_rdnssi_addr[i], prefix_str, sizeof(prefix_str));
 				printf(" %s", prefix_str);
 			}
 

send.c

@@ -584,8 +584,10 @@ static struct safe_buffer_list *add_ra_options_route(struct safe_buffer_list *sb
 static struct safe_buffer_list *add_ra_options_rdnss(struct safe_buffer_list *sbl, struct Interface const *iface,
 						     struct AdvRDNSS const *rdnss, int cease_adv, struct in6_addr const *dest)
 {
+	struct safe_buffer *rdnss_addr = new_safe_buffer();
 	while (rdnss) {
 		struct nd_opt_rdnss_info_local rdnssinfo;
+		rdnss_addr->used = 0;
 
 		if (!cease_adv && !schedule_option_rdnss(dest, iface, rdnss)) {
 			rdnss = rdnss->next;
@@ -594,6 +596,12 @@ static struct safe_buffer_list *add_ra_options_rdnss(struct safe_buffer_list *sb
 
 		memset(&rdnssinfo, 0, sizeof(rdnssinfo));
 
+		size_t const bytes = sizeof(rdnssinfo) + sizeof(struct in6_addr) * rdnss->AdvRDNSSNumber;
+		if (bytes > (256 * 8)) {
+			flog(LOG_ERR, "RDNSS too long for RA option, must be < 2048 bytes.  Exiting.");
+			exit(1);
+		}
+
 		rdnssinfo.nd_opt_rdnssi_type = ND_OPT_RDNSS_INFORMATION;
 		rdnssinfo.nd_opt_rdnssi_len = 1 + 2 * rdnss->AdvRDNSSNumber;
 		rdnssinfo.nd_opt_rdnssi_pref_flag_reserved = 0;
@@ -604,16 +612,17 @@ static struct safe_buffer_list *add_ra_options_rdnss(struct safe_buffer_list *sb
 			rdnssinfo.nd_opt_rdnssi_lifetime = htonl(rdnss->AdvRDNSSLifetime);
 		}
 
-		memcpy(&rdnssinfo.nd_opt_rdnssi_addr1, &rdnss->AdvRDNSSAddr1, sizeof(struct in6_addr));
-		memcpy(&rdnssinfo.nd_opt_rdnssi_addr2, &rdnss->AdvRDNSSAddr2, sizeof(struct in6_addr));
-		memcpy(&rdnssinfo.nd_opt_rdnssi_addr3, &rdnss->AdvRDNSSAddr3, sizeof(struct in6_addr));
-
 		sbl = safe_buffer_list_append(sbl);
-		safe_buffer_append(sbl->sb, &rdnssinfo,
-				   sizeof(rdnssinfo) - (3 - rdnss->AdvRDNSSNumber) * sizeof(struct in6_addr));
+		safe_buffer_append(sbl->sb, &rdnssinfo, sizeof(rdnssinfo));
+		for (int i = 0; i < rdnss->AdvRDNSSNumber; i++) { 
+			safe_buffer_append(rdnss_addr, &rdnss->AdvRDNSSAddr[i], sizeof(struct in6_addr));
+		}
+		safe_buffer_append(sbl->sb, rdnssbuf->buffer, rdnssbuf->used);
+		safe_buffer_free(rdnssbuf);
 
 		rdnss = rdnss->next;
 	}
+	safe_buffer_free(rdnss_addr);
 
 	return sbl;
 }

util.c

@@ -187,10 +187,10 @@ void addrtostr(struct in6_addr const *addr, char *str, size_t str_size)
 int check_rdnss_presence(struct AdvRDNSS *rdnss, struct in6_addr *addr)
 {
 	while (rdnss) {
-		if (!memcmp(&rdnss->AdvRDNSSAddr1, addr, sizeof(struct in6_addr)) ||
-		    !memcmp(&rdnss->AdvRDNSSAddr2, addr, sizeof(struct in6_addr)) ||
-		    !memcmp(&rdnss->AdvRDNSSAddr3, addr, sizeof(struct in6_addr)))
-			return 1; /* rdnss address found in the list */
+		for (int i = 0; i < rdnss->AdvRDNSSNumber; i++) {
+			if (!memcmp(&rdnss->AdvRDNSSAddr[i], addr, sizeof(struct in6_addr)))
+				return 1; /* rdnss address found in the list */
+		}
 		rdnss = rdnss->next;
 	}
 	return 0;