ipv6_dhcp: Add RFC6334 AFTR-Name option support

4 files changed, 90 insertions, 1 deletions

diff --git a/accel-pppd/accel-ppp.conf.5 b/accel-pppd/accel-ppp.conf.5
index 1086a4ce..1c7fb9fd 100644
--- a/accel-pppd/accel-ppp.conf.5
+++ b/accel-pppd/accel-ppp.conf.5
@@ -73,6 +73,10 @@ IPv4 address assigning module.
 .br
 IPv6 address assigning module.
 .TP
+.BI ipv6_dhcp
+.br
+IPv6 DHCP module.
+.TP
 .BI sigchld
 Helper module to manage child processes, required by pppd_compat
 .TP
@@ -1148,6 +1152,10 @@ Specifies which Radius attribute contains pool name.
 .TP
 .BI "vendor=" vendor
 If attribute is vendor-specific then specify vendor name in this option.
+.SH [ipv6-dhcp]
+.TP
+.BI "aftr-gw=" name
+Specifies the AFTR-Name option value to be returned on DHCPv6 replies upon request from the client.
 .SH [ipv6-pool]
 .br
 Configuration of ipv6pool module.
diff --git a/accel-pppd/ipv6/dhcpv6.c b/accel-pppd/ipv6/dhcpv6.c
index 158771b1..77fc32f7 100644
--- a/accel-pppd/ipv6/dhcpv6.c
+++ b/accel-pppd/ipv6/dhcpv6.c
@@ -40,6 +40,9 @@ static int conf_pref_lifetime = 604800;
 static int conf_valid_lifetime = 2592000;
 static struct dhcpv6_opt_serverid *conf_serverid = &serverid.hdr;
 static int conf_route_via_gw = 1;
+static uint8_t *conf_aftr_gw;
+static int conf_aftr_gw_size;
+
 
 static struct in6_addr conf_dns[MAX_DNS_COUNT];
 static int conf_dns_count;
@@ -233,6 +236,11 @@ static void insert_oro(struct dhcpv6_packet *reply, struct dhcpv6_option *opt)
 				opt1 = dhcpv6_option_alloc(reply, D6_OPTION_DOMAIN_LIST, conf_dnssl_size);
 				memcpy(opt1->hdr->data, conf_dnssl, conf_dnssl_size);
 			}
+		} else if (ntohs(*ptr) == D6_OPTION_AFTR_NAME) {
+			if (conf_aftr_gw_size) {
+				opt1 = dhcpv6_option_alloc(reply, D6_OPTION_AFTR_NAME, conf_aftr_gw_size);
+				memcpy(opt1->hdr->data, conf_aftr_gw, conf_aftr_gw_size);
+			}
 		}
 	}
 }
@@ -831,6 +839,53 @@ static int dhcpv6_read(struct triton_md_handler_t *h)
 	return 0;
 }
 
+static void add_aftr_gw(const char *val)
+{
+	int n = strlen(val);
+	const char *ptr;
+	uint8_t *buf;
+
+	if (!val)
+		return;
+
+	if (val[n - 1] == '.')
+		n++;
+	else
+		n += 2;
+
+	if (n > 255) {
+		log_error("dnsv6: AFTR-Name '%s' is too long\n", val);
+		return;
+	}
+
+	if (!conf_aftr_gw)
+		conf_aftr_gw = _malloc(n);
+	else
+		conf_aftr_gw = _realloc(conf_aftr_gw, conf_aftr_gw_size + n);
+
+	buf = conf_aftr_gw + conf_aftr_gw_size;
+
+	while (1) {
+		ptr = strchr(val, '.');
+		if (!ptr)
+			ptr = strchr(val, 0);
+		if (ptr - val > 63) {
+			log_error("dnsv6: AFTR-Name '%s' is invalid\n", val);
+			return;
+		}
+		*buf = ptr - val;
+		memcpy(buf + 1, val, ptr - val);
+		buf += 1 + (ptr - val);
+		val = ptr + 1;
+		if (!*ptr || !*val) {
+			*buf = 0;
+			break;
+		}
+	}
+
+	conf_aftr_gw_size += n;
+}
+
 static void add_dnssl(const char *val)
 {
 	int n = strlen(val);
@@ -959,6 +1014,12 @@ static void load_config(void)
 	if (opt)
 		conf_route_via_gw = atoi(opt);
 
+	opt = conf_get_opt("ipv6-dhcp", "aftr-gw");
+	if (opt) {
+		add_aftr_gw(opt);
+	}
+
+
 	opt = conf_get_opt("ipv6-dhcp", "server-id");
 	if (opt)
 		id = parse_serverid(opt);
diff --git a/accel-pppd/ipv6/dhcpv6.h b/accel-pppd/ipv6/dhcpv6.h
index 32ee7154..2326e639 100644
--- a/accel-pppd/ipv6/dhcpv6.h
+++ b/accel-pppd/ipv6/dhcpv6.h
@@ -34,7 +34,7 @@
 #define D6_OPTION_DOMAIN_LIST     24
 #define D6_OPTION_IA_PD           25
 #define D6_OPTION_IAPREFIX        26
-#define D6_OPTION_IAPREFIX        26
+#define D6_OPTION_AFTR_NAME       64
 
 #define D6_SOLICIT                 1
 #define D6_ADVERTISE               2
diff --git a/accel-pppd/ipv6/dhcpv6_packet.c b/accel-pppd/ipv6/dhcpv6_packet.c
index 4173ba78..1890bc11 100644
--- a/accel-pppd/ipv6/dhcpv6_packet.c
+++ b/accel-pppd/ipv6/dhcpv6_packet.c
@@ -31,6 +31,7 @@ static void print_status(struct dhcpv6_option *opt, void (*print)(const char *fm
 static void print_reconf(struct dhcpv6_option *opt, void (*print)(const char *fmt, ...));
 static void print_dnssl(struct dhcpv6_option *opt, void (*print)(const char *fmt, ...));
 static void print_ia_prefix(struct dhcpv6_option *opt, void (*print)(const char *fmt, ...));
+static void print_aftr_gw(struct dhcpv6_option *opt, void (*print)(const char *fmt, ...));
 
 static struct dict_option known_options[] = {
 	{ D6_OPTION_CLIENTID, "Client-ID", 1, 0, print_clientid },
@@ -56,6 +57,7 @@ static struct dict_option known_options[] = {
 	{ D6_OPTION_DOMAIN_LIST, "DNSSL", 1, 0, print_dnssl },
 	{ D6_OPTION_IA_PD, "IA-PD", 1, sizeof(struct dhcpv6_opt_ia_na), print_ia_na },
 	{ D6_OPTION_IAPREFIX, "IA-Prefix", 1, sizeof(struct dhcpv6_opt_ia_prefix), print_ia_prefix },
+	{ D6_OPTION_AFTR_NAME, "AFTR-Name", 1, 0, print_aftr_gw },
 	{ 0 }
 };
 
@@ -549,6 +551,24 @@ static void print_dnssl(struct dhcpv6_option *opt, void (*print)(const char *fmt
 
 }
 
+static void print_aftr_gw(struct dhcpv6_option *opt, void (*print)(const char *fmt, ...)) {
+	int len = ntohs(opt->hdr->len);
+	int offset = 0;
+	char domain[255];
+	uint8_t label_len;
+
+	memset(domain, 0, 255);
+	while (offset < len) {
+		label_len = opt->hdr->data[offset];
+		if (label_len == 0)
+			break;
+		memcpy(&domain[offset], &opt->hdr->data[offset + 1], label_len);
+		offset += label_len;
+		domain[offset++] = '.';
+	}
+	print(" %s", domain);
+}
+
 static void print_ia_prefix(struct dhcpv6_option *opt, void (*print)(const char *fmt, ...))
 {
 	struct dhcpv6_opt_ia_prefix *o = (struct dhcpv6_opt_ia_prefix *)opt->hdr;