dhcpv6-ia: implement temporary addresses (IA_TA)

5 files changed, 88 insertions, 41 deletions

diff --git a/src/config.c b/src/config.c
index bbac334..824b30d 100644
--- a/src/config.c
+++ b/src/config.c
@@ -39,7 +39,7 @@ struct config config = {.legacy = false, .main_dhcpv4 = false,
 #define HOSTID_LEN_MAX	64
 #define HOSTID_LEN_DEFAULT HOSTID_LEN_MIN
 
-#define OAF_DHCPV6	(OAF_DHCPV6_NA | OAF_DHCPV6_PD)
+#define OAF_DHCPV6	(OAF_DHCPV6_NA | OAF_DHCPV6_PD | OAF_DHCPV6_TA)
 
 enum {
 	IFACE_ATTR_INTERFACE,
@@ -65,6 +65,7 @@ enum {
 	IFACE_ATTR_DHCPV6_ASSIGNALL,
 	IFACE_ATTR_DHCPV6_PD,
 	IFACE_ATTR_DHCPV6_NA,
+	IFACE_ATTR_DHCPV6_TA,
 	IFACE_ATTR_DHCPV6_HOSTID_LEN,
 	IFACE_ATTR_RA_DEFAULT,
 	IFACE_ATTR_RA_MANAGEMENT,
@@ -115,6 +116,7 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
 	[IFACE_ATTR_DHCPV6_ASSIGNALL] = { .name ="dhcpv6_assignall", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_DHCPV6_PD] = { .name = "dhcpv6_pd", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_DHCPV6_NA] = { .name = "dhcpv6_na", .type = BLOBMSG_TYPE_BOOL },
+	[IFACE_ATTR_DHCPV6_TA] = { .name = "dhcpv6_ta", .type = BLOBMSG_TYPE_BOOL },
 	[IFACE_ATTR_DHCPV6_HOSTID_LEN] = { .name = "dhcpv6_hostidlength", .type = BLOBMSG_TYPE_INT32 },
 	[IFACE_ATTR_PD_MANAGER] = { .name = "pd_manager", .type = BLOBMSG_TYPE_STRING },
 	[IFACE_ATTR_PD_CER] = { .name = "pd_cer", .type = BLOBMSG_TYPE_STRING },
@@ -213,6 +215,7 @@ static void set_interface_defaults(struct interface *iface)
 	iface->dhcpv6_assignall = true;
 	iface->dhcpv6_pd = true;
 	iface->dhcpv6_na = true;
+	iface->dhcpv6_ta = true;
 	iface->dhcpv6_hostid_len = HOSTID_LEN_DEFAULT;
 	iface->dns_service = true;
 	iface->ra_flags = ND_RA_FLAG_OTHER;
@@ -768,6 +771,9 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 	if ((c = tb[IFACE_ATTR_DHCPV6_NA]))
 		iface->dhcpv6_na = blobmsg_get_bool(c);
 
+	if ((c = tb[IFACE_ATTR_DHCPV6_TA]))
+		iface->dhcpv6_ta = blobmsg_get_bool(c);
+
 	if ((c = tb[IFACE_ATTR_DHCPV6_HOSTID_LEN])) {
 		uint32_t hostid_len = blobmsg_get_u32(c);
 
diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index bd4b6e1..bb13b9f 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -53,6 +53,7 @@ static struct uloop_timeout valid_until_timeout = {.cb = valid_until_cb};
 static uint32_t serial = 0;
 static uint8_t statemd5[16];
 static prng_context_t *prng;
+static uint64_t ta_seed = 0;	/* TODO initialize from stable storage, or with random value. */
 
 int dhcpv6_ia_init(void)
 {
@@ -248,12 +249,12 @@ void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
 		pref = addrs[i].preferred;
 		valid = addrs[i].valid;
 
-		if (c->flags & OAF_DHCPV6_NA) {
+		if (c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA)) {
 			if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 				continue;
 
-			addr.s6_addr32[2] = htonl(c->assigned_host_id >> 32);
-			addr.s6_addr32[3] = htonl(c->assigned_host_id & UINT32_MAX);
+			addr.s6_addr32[2] |= htonl(c->assigned_host_id >> 32);
+			addr.s6_addr32[3] |= htonl(c->assigned_host_id & UINT32_MAX);
 		} else {
 			if (!valid_prefix_length(c, addrs[i].prefix))
 				continue;
@@ -299,7 +300,7 @@ static void dhcpv6_write_ia_addr(struct in6_addr *addr, int prefix, _unused uint
 
 	inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf) - 1);
 
-	if ((ctxt->c->flags & OAF_DHCPV6_NA) && ctxt->c->hostname &&
+	if ((ctxt->c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA)) && ctxt->c->hostname &&
 	    !(ctxt->c->flags & OAF_BROKEN_HOSTNAME)) {
 		fputs(ipbuf, ctxt->fp);
 
@@ -376,7 +377,7 @@ void dhcpv6_ia_write_statefile(void)
 									(int64_t)(ctxt.c->valid_until - now + wall_time) :
 									(INFINITE_VALID(ctxt.c->valid_until) ? -1 : 0)));
 
-					if (ctxt.c->flags & OAF_DHCPV6_NA)
+					if (ctxt.c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA))
 						ctxt.buf_idx += snprintf(ctxt.buf + ctxt.buf_idx, ctxt.buf_len - ctxt.buf_idx,
 									 "%" PRIx64" %u ", ctxt.c->assigned_host_id, (unsigned)ctxt.c->length);
 					else
@@ -460,7 +461,7 @@ void dhcpv6_ia_write_statefile(void)
 static void __apply_lease(struct dhcp_assignment *a,
 		struct odhcpd_ipaddr *addrs, ssize_t addr_len, bool add)
 {
-	if (a->flags & OAF_DHCPV6_NA)
+	if (a->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA))
 		return;
 
 	for (ssize_t i = 0; i < addr_len; ++i) {
@@ -640,7 +641,7 @@ static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 	uint32_t current = 1, asize = (1 << (64 - assign->length)) - 1;
 	if (assign->assigned_subnet_id) {
 		list_for_each_entry(c, &iface->ia_assignments, head) {
-			if (c->flags & OAF_DHCPV6_NA)
+			if (c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA))
 				continue;
 
 			if (assign->assigned_subnet_id >= current && assign->assigned_subnet_id + asize < c->assigned_subnet_id) {
@@ -659,7 +660,7 @@ static bool assign_pd(struct interface *iface, struct dhcp_assignment *assign)
 	/* Fallback to a variable assignment */
 	current = 1;
 	list_for_each_entry(c, &iface->ia_assignments, head) {
-		if (c->flags & OAF_DHCPV6_NA)
+		if (c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA))
 			continue;
 
 		current = (current + asize) & (~asize);
@@ -701,14 +702,14 @@ static bool is_reserved_ipv6_iid(uint64_t iid)
 	return false;
 }
 
-static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
+static bool assign_na(struct interface *iface, struct dhcp_assignment *a, bool is_ta)
 {
 	struct dhcp_assignment *c;
 
 	/* Preconfigured assignment by static lease */
 	if (a->assigned_host_id) {
 		list_for_each_entry(c, &iface->ia_assignments, head) {
-			if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > a->assigned_host_id ) {
+			if (!(c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA)) || c->assigned_host_id > a->assigned_host_id ) {
 				list_add_tail(&a->head, &c->head);
 				return true;
 			} else if (c->assigned_host_id == a->assigned_host_id)
@@ -729,12 +730,25 @@ static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 		uint64_t try = 0;
 		uint32_t counter_be = htonl(counter);
 
-		prng_starts(prng);
-		prng_update(prng, a->clid_data, a->clid_len);
-		prng_update(prng, (const uint8_t*)&a->iaid, sizeof(a->iaid));
-		prng_update(prng, (const uint8_t*)&counter_be, sizeof(counter_be));
-		prng_update(prng, (const uint8_t*)&config.secret_key, sizeof(config.secret_key));
-		prng_finish(prng, (uint8_t*)&try);
+		if (is_ta) {
+			prng_starts(prng);
+			prng_update(prng, (const uint8_t*)&ta_seed, sizeof(ta_seed));
+			prng_update(prng, a->clid_data, a->clid_len);
+			prng_update(prng, (const uint8_t*)&is_ta, sizeof(is_ta));
+			prng_update(prng, (const uint8_t*)&a->iaid, sizeof(a->iaid));
+			prng_finish(prng, (uint8_t*)&try, (uint8_t*)&ta_seed);
+			/* TODO set leftmost 64-bits of the MD5 digest
+			   and set bit 6 (the leftmost bit is numbered
+			   0) to zero. */
+		} else {
+			prng_starts(prng);
+			prng_update(prng, a->clid_data, a->clid_len);
+			prng_update(prng, (const uint8_t*)&a->iaid, sizeof(a->iaid));
+			prng_update(prng, (const uint8_t*)&is_ta, sizeof(is_ta));
+			prng_update(prng, (const uint8_t*)&counter_be, sizeof(counter_be));
+			prng_update(prng, (const uint8_t*)&config.secret_key, sizeof(config.secret_key));
+			prng_finish(prng, (uint8_t*)&try, NULL);
+		}
 
 		try &= mask;
 
@@ -750,7 +764,7 @@ static bool assign_na(struct interface *iface, struct dhcp_assignment *a)
 			continue;
 
 		list_for_each_entry(c, &iface->ia_assignments, head) {
-			if (!(c->flags & OAF_DHCPV6_NA) || c->assigned_host_id > try) {
+			if (!(c->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA)) || c->assigned_host_id > try) {
 				a->assigned_host_id = try;
 				list_add_tail(&a->head, &c->head);
 				return true;
@@ -867,16 +881,24 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 		const struct dhcpv6_ia_hdr *ia, struct dhcp_assignment *a,
 		struct interface *iface, bool request)
 {
+	bool is_ta = ia->type == htons(DHCPV6_OPT_IA_TA);
 	struct dhcpv6_ia_hdr o_ia = {
 		.type = ia->type,
 		.len = 0,
 		.iaid = ia->iaid,
-		.t1 = 0,
-		.t2 = 0,
+		.t1 = 0,	/* not in IA_TA */
+		.t2 = 0,	/* not in IA_TA */
 	};
-	size_t ia_len = sizeof(o_ia);
+	size_t ia_hdr_len;
 	time_t now = odhcpd_time();
 
+	if (is_ta)
+		ia_hdr_len = sizeof(o_ia) - sizeof(o_ia.t1) - sizeof(o_ia.t2);
+	else
+		ia_hdr_len = sizeof(o_ia);
+
+	size_t ia_len = ia_hdr_len;
+
 	if (buflen < ia_len)
 		return 0;
 
@@ -895,7 +917,7 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 		ia_len += sizeof(o_status);
 
 		o_ia.len = htons(ia_len - 4);
-		memcpy(buf, &o_ia, sizeof(o_ia));
+		memcpy(buf, &o_ia, ia_hdr_len);
 
 		return ia_len;
 	}
@@ -973,7 +995,7 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 				ia_len += sizeof(o_ia_p);
 			}
 
-			if (a->flags & OAF_DHCPV6_NA) {
+			if (a->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA)) {
 				struct dhcpv6_ia_addr o_ia_a = {
 					.type = htons(DHCPV6_OPT_IA_ADDR),
 					.len = htons(sizeof(o_ia_a) - 4),
@@ -982,8 +1004,8 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 					.valid = htonl(prefix_valid)
 				};
 
-				o_ia_a.addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
-				o_ia_a.addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
+				o_ia_a.addr.s6_addr32[2] |= htonl(a->assigned_host_id >> 32);
+				o_ia_a.addr.s6_addr32[3] |= htonl(a->assigned_host_id & UINT32_MAX);
 
 				if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs))
 					continue;
@@ -1061,8 +1083,8 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 								ia_p->prefix == ((a->managed) ? addrs[i].prefix : a->length))
 							found = true;
 					} else {
-						addr.s6_addr32[2] = htonl(a->assigned_host_id >> 32);
-						addr.s6_addr32[3] = htonl(a->assigned_host_id & UINT32_MAX);
+						addr.s6_addr32[2] |= htonl(a->assigned_host_id >> 32);
+						addr.s6_addr32[3] |= htonl(a->assigned_host_id & UINT32_MAX);
 
 						if (!memcmp(&ia_a->addr, &addr, sizeof(addr)))
 							found = true;
@@ -1106,7 +1128,7 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 	}
 
 	o_ia.len = htons(ia_len - 4);
-	memcpy(buf, &o_ia, sizeof(o_ia));
+	memcpy(buf, &o_ia, ia_hdr_len);
 	return ia_len;
 }
 
@@ -1128,10 +1150,11 @@ static void dhcpv6_log_ia_addr(struct in6_addr *addr, int prefix, _unused uint32
 }
 
 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
-		const char *duidbuf, bool is_pd, struct dhcp_assignment *a, int code)
+		const char *duidbuf, uint16_t otype, struct dhcp_assignment *a, int code)
 {
 	const char *type = "UNKNOWN";
 	const char *status = "UNKNOWN";
+	const char *lease_type = "UNKNOWN";
 
 	switch (msgtype) {
 	case DHCPV6_MSG_SOLICIT:
@@ -1175,6 +1198,18 @@ static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 		break;
 	}
 
+	switch (otype) {
+	case DHCPV6_OPT_IA_NA:
+		lease_type = "IA_NA";
+		break;
+	case DHCPV6_OPT_IA_TA:
+		lease_type = "IA_TA";
+		break;
+	case DHCPV6_OPT_IA_PD:
+		lease_type = "IA_PD";
+		break;
+	}
+
 	char leasebuf[256] = "";
 
 	if (a) {
@@ -1185,7 +1220,7 @@ static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 		dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_log_ia_addr, &ctxt);
 	}
 
-	syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, (is_pd) ? "IA_PD" : "IA_NA",
+	syslog(LOG_INFO, "DHCPV6 %s %s from %s on %s: %s %s", type, lease_type,
 			 duidbuf, iface->name, status, leasebuf);
 }
 
@@ -1282,8 +1317,9 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 	dhcpv6_for_each_option(start, end, otype, olen, odata) {
 		bool is_pd = (otype == DHCPV6_OPT_IA_PD);
 		bool is_na = (otype == DHCPV6_OPT_IA_NA);
+		bool is_ta = (otype == DHCPV6_OPT_IA_TA);
 		bool ia_addr_present = false;
-		if (!is_pd && !is_na)
+		if (!is_pd && !is_na && !is_ta)
 			continue;
 
 		struct dhcpv6_ia_hdr *ia = (struct dhcpv6_ia_hdr*)&odata[-4];
@@ -1310,7 +1346,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 
 			if (reqlen > 64)
 				reqlen = 64;
-		} else if (is_na) {
+		} else if (is_na || is_ta) {
 			uint8_t *sdata;
 			uint16_t stype, slen;
 			dhcpv6_for_each_option(&ia[1], odata + olen, stype, slen, sdata) {
@@ -1326,7 +1362,9 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 		list_for_each_entry(c, &iface->ia_assignments, head) {
 			if ((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) &&
 			    c->iaid == ia->iaid && (INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
-			    ((is_pd && (c->flags & OAF_DHCPV6_PD)) || (is_na && (c->flags & OAF_DHCPV6_NA)))) {
+			    ((is_pd && (c->flags & OAF_DHCPV6_PD)) ||
+			     (is_na && (c->flags & OAF_DHCPV6_NA)) ||
+			     (is_ta && (c->flags & OAF_DHCPV6_TA)))) {
 				a = c;
 
 				/* Reset state */
@@ -1365,7 +1403,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 						a->iaid = ia->iaid;
 						a->length = reqlen;
 						a->peer = *addr;
-						if (is_na)
+						if (is_na || is_ta)
 							a->assigned_host_id = l ? l->hostid : 0;
 						else
 							a->assigned_subnet_id = reqhint;
@@ -1373,7 +1411,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 						a->preferred_until =  now;
 						a->dhcp_free_cb = dhcpv6_ia_free_assignment;
 						a->iface = iface;
-						a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
+						a->flags = (is_pd ? OAF_DHCPV6_PD : is_ta ? OAF_DHCPV6_TA : OAF_DHCPV6_NA);
 
 						if (first)
 							memcpy(a->key, first->key, sizeof(a->key));
@@ -1383,8 +1421,8 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 						if (is_pd && iface->dhcpv6_pd)
 							while (!(assigned = assign_pd(iface, a)) &&
 							       !a->managed_size && ++a->length <= 64);
-						else if (is_na && iface->dhcpv6_na)
-							assigned = assign_na(iface, a);
+						else if ((is_na && iface->dhcpv6_na) || (is_ta && iface->dhcpv6_ta))
+							assigned = assign_na(iface, a, is_ta);
 
 						if (l && assigned) {
 							a->flags |= OAF_STATIC;
@@ -1494,7 +1532,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 				}
 			} else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
 				a->valid_until = now - 1;
-			} else if ((a->flags & OAF_DHCPV6_NA) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
+			} else if ((a->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA)) && hdr->msg_type == DHCPV6_MSG_DECLINE) {
 				a->flags &= ~OAF_BOUND;
 
 				if (!(a->flags & OAF_STATIC) || a->lease->hostid != a->assigned_host_id) {
@@ -1518,7 +1556,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 		buf += ia_response_len;
 		buflen -= ia_response_len;
 		response_len += ia_response_len;
-		dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
+		dhcpv6_log(hdr->msg_type, iface, now, duidbuf, otype, a, status);
 	}
 
 	switch (hdr->msg_type) {
diff --git a/src/dhcpv6.h b/src/dhcpv6.h
index c96dc0d..a12c896 100644
--- a/src/dhcpv6.h
+++ b/src/dhcpv6.h
@@ -41,6 +41,7 @@
 #define DHCPV6_OPT_CLIENTID 1
 #define DHCPV6_OPT_SERVERID 2
 #define DHCPV6_OPT_IA_NA 3
+#define DHCPV6_OPT_IA_TA 4
 #define DHCPV6_OPT_IA_ADDR 5
 #define DHCPV6_OPT_ORO 6
 #define DHCPV6_OPT_STATUS 13
diff --git a/src/odhcpd.h b/src/odhcpd.h
index fff28d5..d1463e1 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -141,6 +141,7 @@ enum odhcpd_assignment_flags {
 	OAF_DHCPV4		= (1 << 4),
 	OAF_DHCPV6_NA		= (1 << 5),
 	OAF_DHCPV6_PD		= (1 << 6),
+	OAF_DHCPV6_TA		= (1 << 7),
 };
 
 struct config {
@@ -205,7 +206,7 @@ struct dhcp_assignment {
 		uint32_t assigned_subnet_id;
 	};
 	uint32_t iaid;
-	uint8_t length; // length == 128 -> IA_NA, length <= 64 -> IA_PD
+	uint8_t length; // length == 128 -> IA_NA or IA_TA, length <= 64 -> IA_PD
 
 	struct odhcpd_ipaddr *managed;
 	ssize_t managed_size;
@@ -327,6 +328,7 @@ struct interface {
 	bool dhcpv6_assignall;
 	bool dhcpv6_pd;
 	bool dhcpv6_na;
+	bool dhcpv6_ta;
 	uint32_t dhcpv6_hostid_len;
 
 	char *upstream;
diff --git a/src/ubus.c b/src/ubus.c
index 45b29a4..25c2b1b 100644
--- a/src/ubus.c
+++ b/src/ubus.c
@@ -158,7 +158,7 @@ static int handle_dhcpv6_leases(_unused struct ubus_context *ctx, _unused struct
 				blobmsg_add_string(&b, NULL, "static");
 			blobmsg_close_array(&b, m);
 
-			m = blobmsg_open_array(&b, a->flags & OAF_DHCPV6_NA ? "ipv6-addr": "ipv6-prefix");
+			m = blobmsg_open_array(&b, a->flags & (OAF_DHCPV6_NA | OAF_DHCPV6_TA) ? "ipv6-addr": "ipv6-prefix");
 			dhcpv6_ia_enum_addrs(iface, a, now, dhcpv6_blobmsg_ia_addr, NULL);
 			blobmsg_close_table(&b, m);