1 files changed, 467 insertions, 0 deletions

diff --git a/nhrpd/nhrp_nhs.c b/nhrpd/nhrp_nhs.c
new file mode 100644
index 0000000..03b4b53
--- /dev/null
+++ b/nhrpd/nhrp_nhs.c
@@ -0,0 +1,467 @@
+/* NHRP NHC nexthop server functions (registration)
+ * Copyright (c) 2014-2015 Timo Teräs
+ *
+ * This file is free software: you may copy, redistribute 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.
+ */
+
+#include "zebra.h"
+#include "zbuf.h"
+#include "memory.h"
+#include "thread.h"
+#include "nhrpd.h"
+#include "nhrp_protocol.h"
+
+DEFINE_MTYPE_STATIC(NHRPD, NHRP_NHS, "NHRP next hop server");
+DEFINE_MTYPE_STATIC(NHRPD, NHRP_REGISTRATION, "NHRP registration entries");
+
+static void nhrp_nhs_resolve(struct thread *t);
+static void nhrp_reg_send_req(struct thread *t);
+
+static void nhrp_reg_reply(struct nhrp_reqid *reqid, void *arg)
+{
+	struct nhrp_packet_parser *p = arg;
+	struct nhrp_registration *r =
+		container_of(reqid, struct nhrp_registration, reqid);
+	struct nhrp_nhs *nhs = r->nhs;
+	struct interface *ifp = nhs->ifp;
+	struct nhrp_interface *nifp = ifp->info;
+	struct nhrp_extension_header *ext;
+	struct nhrp_cie_header *cie;
+	struct nhrp_cache *c;
+	struct zbuf extpl;
+	union sockunion cie_nbma, cie_nbma_nhs, cie_proto, cie_proto_nhs,
+		*proto;
+	int ok = 0, holdtime;
+	unsigned short mtu = 0;
+
+	nhrp_reqid_free(&nhrp_packet_reqid, &r->reqid);
+
+	if (p->hdr->type != NHRP_PACKET_REGISTRATION_REPLY) {
+		debugf(NHRP_DEBUG_COMMON, "NHS: Registration failed");
+		return;
+	}
+
+	debugf(NHRP_DEBUG_COMMON, "NHS: Reg.reply received");
+
+	ok = 1;
+	while ((cie = nhrp_cie_pull(&p->payload, p->hdr, &cie_nbma, &cie_proto))
+	       != NULL) {
+		proto = sockunion_family(&cie_proto) != AF_UNSPEC
+				? &cie_proto
+				: &p->src_proto;
+		debugf(NHRP_DEBUG_COMMON, "NHS: CIE registration: %pSU: %d",
+		       proto, cie->code);
+		if (!((cie->code == NHRP_CODE_SUCCESS)
+		      || (cie->code == NHRP_CODE_ADMINISTRATIVELY_PROHIBITED
+			  && nhs->hub)))
+			ok = 0;
+		mtu = ntohs(cie->mtu);
+		debugf(NHRP_DEBUG_COMMON, "NHS: CIE MTU: %d", mtu);
+	}
+
+	if (!ok)
+		return;
+
+	/* Parse extensions */
+	sockunion_family(&nifp->nat_nbma) = AF_UNSPEC;
+	sockunion_family(&cie_nbma_nhs) = AF_UNSPEC;
+	while ((ext = nhrp_ext_pull(&p->extensions, &extpl)) != NULL) {
+		switch (htons(ext->type) & ~NHRP_EXTENSION_FLAG_COMPULSORY) {
+		case NHRP_EXTENSION_NAT_ADDRESS:
+			/* NHS adds second CIE if NAT is detected */
+			if (nhrp_cie_pull(&extpl, p->hdr, &cie_nbma, &cie_proto)
+			    && nhrp_cie_pull(&extpl, p->hdr, &cie_nbma,
+					     &cie_proto)) {
+				nifp->nat_nbma = cie_nbma;
+				debugf(NHRP_DEBUG_IF,
+				       "%s: NAT detected, real NBMA address: %pSU",
+				       ifp->name, &nifp->nbma);
+			}
+			break;
+		case NHRP_EXTENSION_RESPONDER_ADDRESS:
+			/* NHS adds its own record as responder address */
+			nhrp_cie_pull(&extpl, p->hdr, &cie_nbma_nhs,
+				      &cie_proto_nhs);
+			break;
+		}
+	}
+
+	/* Success - schedule next registration, and route NHS */
+	r->timeout = 2;
+	holdtime = nifp->afi[nhs->afi].holdtime;
+	THREAD_OFF(r->t_register);
+
+	/* RFC 2332 5.2.3 - Registration is recommend to be renewed
+	 * every one third of holdtime */
+	thread_add_timer(master, nhrp_reg_send_req, r, holdtime / 3,
+			 &r->t_register);
+
+	r->proto_addr = p->dst_proto;
+	c = nhrp_cache_get(ifp, &p->dst_proto, 1);
+	if (c)
+		nhrp_cache_update_binding(c, NHRP_CACHE_NHS, holdtime,
+					  nhrp_peer_ref(r->peer), mtu, NULL,
+					  &cie_nbma_nhs);
+}
+
+static void nhrp_reg_timeout(struct thread *t)
+{
+	struct nhrp_registration *r = THREAD_ARG(t);
+	struct nhrp_cache *c;
+
+
+	if (r->timeout >= 16 && sockunion_family(&r->proto_addr) != AF_UNSPEC) {
+		nhrp_reqid_free(&nhrp_packet_reqid, &r->reqid);
+		c = nhrp_cache_get(r->nhs->ifp, &r->proto_addr, 0);
+		if (c)
+			nhrp_cache_update_binding(c, NHRP_CACHE_NHS, -1, NULL,
+						  0, NULL, NULL);
+		sockunion_family(&r->proto_addr) = AF_UNSPEC;
+	}
+
+	r->timeout <<= 1;
+	if (r->timeout > 64) {
+		/* If registration fails repeatedly, this may be because the
+		 * IPSec connection is not working. Close the connection so it
+		 * can be re-established correctly
+		 */
+		if (r->peer && r->peer->vc && r->peer->vc->ike_uniqueid) {
+			debugf(NHRP_DEBUG_COMMON,
+			       "Terminating IPSec Connection for %d",
+			       r->peer->vc->ike_uniqueid);
+			vici_terminate_vc_by_ike_id(r->peer->vc->ike_uniqueid);
+			r->peer->vc->ike_uniqueid = 0;
+		}
+		r->timeout = 2;
+	}
+	thread_add_timer_msec(master, nhrp_reg_send_req, r, 10, &r->t_register);
+}
+
+static void nhrp_reg_peer_notify(struct notifier_block *n, unsigned long cmd)
+{
+	struct nhrp_registration *r =
+		container_of(n, struct nhrp_registration, peer_notifier);
+
+	switch (cmd) {
+	case NOTIFY_PEER_UP:
+	case NOTIFY_PEER_DOWN:
+	case NOTIFY_PEER_IFCONFIG_CHANGED:
+	case NOTIFY_PEER_MTU_CHANGED:
+		debugf(NHRP_DEBUG_COMMON, "NHS: Flush timer for %pSU",
+		       &r->peer->vc->remote.nbma);
+		THREAD_OFF(r->t_register);
+		thread_add_timer_msec(master, nhrp_reg_send_req, r, 10,
+				      &r->t_register);
+		break;
+	}
+}
+
+static void nhrp_reg_send_req(struct thread *t)
+{
+	struct nhrp_registration *r = THREAD_ARG(t);
+	struct nhrp_nhs *nhs = r->nhs;
+	struct interface *ifp = nhs->ifp;
+	struct nhrp_interface *nifp = ifp->info;
+	struct nhrp_afi_data *if_ad = &nifp->afi[nhs->afi];
+	union sockunion *dst_proto, nhs_proto;
+	struct zbuf *zb;
+	struct nhrp_packet_header *hdr;
+	struct nhrp_extension_header *ext;
+	struct nhrp_cie_header *cie;
+
+	if (!nhrp_peer_check(r->peer, 2)) {
+		debugf(NHRP_DEBUG_COMMON, "NHS: Waiting link for %pSU",
+		       &r->peer->vc->remote.nbma);
+		thread_add_timer(master, nhrp_reg_send_req, r, 120,
+				 &r->t_register);
+		return;
+	}
+
+	thread_add_timer(master, nhrp_reg_timeout, r, r->timeout,
+			 &r->t_register);
+
+	/* RFC2332 5.2.3 NHC uses it's own address as dst if NHS is unknown */
+	dst_proto = &nhs->proto_addr;
+	if (sockunion_family(dst_proto) == AF_UNSPEC)
+		dst_proto = &if_ad->addr;
+
+	debugf(NHRP_DEBUG_COMMON, "NHS: Register %pSU -> %pSU (timeout %d)",
+	       &if_ad->addr, dst_proto, r->timeout);
+
+	/* No protocol address configured for tunnel interface */
+	if (sockunion_family(&if_ad->addr) == AF_UNSPEC)
+		return;
+
+	zb = zbuf_alloc(1400);
+	hdr = nhrp_packet_push(zb, NHRP_PACKET_REGISTRATION_REQUEST,
+			       &nifp->nbma, &if_ad->addr, dst_proto);
+	hdr->hop_count = 1;
+	if (!(if_ad->flags & NHRP_IFF_REG_NO_UNIQUE))
+		hdr->flags |= htons(NHRP_FLAG_REGISTRATION_UNIQUE);
+
+	hdr->u.request_id = htonl(nhrp_reqid_alloc(&nhrp_packet_reqid,
+						   &r->reqid, nhrp_reg_reply));
+
+	/* FIXME: push CIE for each local protocol address */
+	cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, NULL, NULL);
+	/* RFC2332 5.2.1 if unique is set then prefix length must be 0xff */
+	cie->prefix_length = (if_ad->flags & NHRP_IFF_REG_NO_UNIQUE)
+				     ? 8 * sockunion_get_addrlen(dst_proto)
+				     : 0xff;
+	cie->holding_time = htons(if_ad->holdtime);
+	cie->mtu = htons(if_ad->mtu);
+
+	nhrp_ext_request(zb, hdr, ifp);
+
+	/* Cisco NAT detection extension */
+	if (sockunion_family(&r->proto_addr) != AF_UNSPEC) {
+		nhs_proto = r->proto_addr;
+	} else if (sockunion_family(&nhs->proto_addr) != AF_UNSPEC) {
+		nhs_proto = nhs->proto_addr;
+	} else {
+		/* cisco magic: If NHS is not known then use all 0s as
+		 * client protocol address in NAT Extension header
+		 */
+		memset(&nhs_proto, 0, sizeof(nhs_proto));
+		sockunion_family(&nhs_proto) = afi2family(nhs->afi);
+	}
+
+	hdr->flags |= htons(NHRP_FLAG_REGISTRATION_NAT);
+	ext = nhrp_ext_push(zb, hdr, NHRP_EXTENSION_NAT_ADDRESS);
+	/* push NHS details */
+	cie = nhrp_cie_push(zb, NHRP_CODE_SUCCESS, &r->peer->vc->remote.nbma,
+			    &nhs_proto);
+	cie->prefix_length = 8 * sockunion_get_addrlen(&if_ad->addr);
+	cie->mtu = htons(if_ad->mtu);
+	nhrp_ext_complete(zb, ext);
+
+	nhrp_packet_complete(zb, hdr);
+	nhrp_peer_send(r->peer, zb);
+	zbuf_free(zb);
+}
+
+static void nhrp_reg_delete(struct nhrp_registration *r)
+{
+	nhrp_peer_notify_del(r->peer, &r->peer_notifier);
+	nhrp_peer_unref(r->peer);
+	nhrp_reglist_del(&r->nhs->reglist_head, r);
+	THREAD_OFF(r->t_register);
+	XFREE(MTYPE_NHRP_REGISTRATION, r);
+}
+
+static struct nhrp_registration *
+nhrp_reg_by_nbma(struct nhrp_nhs *nhs, const union sockunion *nbma_addr)
+{
+	struct nhrp_registration *r;
+
+	frr_each (nhrp_reglist, &nhs->reglist_head, r)
+		if (sockunion_same(&r->peer->vc->remote.nbma, nbma_addr))
+			return r;
+	return NULL;
+}
+
+static void nhrp_nhs_resolve_cb(struct resolver_query *q, const char *errstr,
+				int n, union sockunion *addrs)
+{
+	struct nhrp_nhs *nhs = container_of(q, struct nhrp_nhs, dns_resolve);
+	struct nhrp_interface *nifp = nhs->ifp->info;
+	struct nhrp_registration *reg;
+	int i;
+
+	if (n < 0) {
+		/* Failed, retry in a moment */
+		thread_add_timer(master, nhrp_nhs_resolve, nhs, 5,
+				 &nhs->t_resolve);
+		return;
+	}
+
+	thread_add_timer(master, nhrp_nhs_resolve, nhs, 2 * 60 * 60,
+			 &nhs->t_resolve);
+
+	frr_each (nhrp_reglist, &nhs->reglist_head, reg)
+		reg->mark = 1;
+
+	nhs->hub = 0;
+	for (i = 0; i < n; i++) {
+		if (sockunion_same(&addrs[i], &nifp->nbma)) {
+			nhs->hub = 1;
+			continue;
+		}
+
+		reg = nhrp_reg_by_nbma(nhs, &addrs[i]);
+		if (reg) {
+			reg->mark = 0;
+			continue;
+		}
+
+		reg = XCALLOC(MTYPE_NHRP_REGISTRATION, sizeof(*reg));
+		reg->peer = nhrp_peer_get(nhs->ifp, &addrs[i]);
+		reg->nhs = nhs;
+		reg->timeout = 1;
+		nhrp_reglist_add_tail(&nhs->reglist_head, reg);
+		nhrp_peer_notify_add(reg->peer, &reg->peer_notifier,
+				     nhrp_reg_peer_notify);
+		thread_add_timer_msec(master, nhrp_reg_send_req, reg, 50,
+				      &reg->t_register);
+	}
+
+	frr_each_safe (nhrp_reglist, &nhs->reglist_head, reg)
+		if (reg->mark)
+			nhrp_reg_delete(reg);
+}
+
+static void nhrp_nhs_resolve(struct thread *t)
+{
+	struct nhrp_nhs *nhs = THREAD_ARG(t);
+
+	resolver_resolve(&nhs->dns_resolve, AF_INET, VRF_DEFAULT,
+			 nhs->nbma_fqdn, nhrp_nhs_resolve_cb);
+}
+
+int nhrp_nhs_add(struct interface *ifp, afi_t afi, union sockunion *proto_addr,
+		 const char *nbma_fqdn)
+{
+	struct nhrp_interface *nifp = ifp->info;
+	struct nhrp_nhs *nhs;
+
+	if (sockunion_family(proto_addr) != AF_UNSPEC
+	    && sockunion_family(proto_addr) != afi2family(afi))
+		return NHRP_ERR_PROTOCOL_ADDRESS_MISMATCH;
+
+	frr_each (nhrp_nhslist, &nifp->afi[afi].nhslist_head, nhs) {
+		if (sockunion_family(&nhs->proto_addr) != AF_UNSPEC
+		    && sockunion_family(proto_addr) != AF_UNSPEC
+		    && sockunion_same(&nhs->proto_addr, proto_addr))
+			return NHRP_ERR_ENTRY_EXISTS;
+
+		if (strcmp(nhs->nbma_fqdn, nbma_fqdn) == 0)
+			return NHRP_ERR_ENTRY_EXISTS;
+	}
+
+	nhs = XMALLOC(MTYPE_NHRP_NHS, sizeof(struct nhrp_nhs));
+
+	*nhs = (struct nhrp_nhs){
+		.afi = afi,
+		.ifp = ifp,
+		.proto_addr = *proto_addr,
+		.nbma_fqdn = strdup(nbma_fqdn),
+		.reglist_head = INIT_DLIST(nhs->reglist_head),
+	};
+	nhrp_nhslist_add_tail(&nifp->afi[afi].nhslist_head, nhs);
+	thread_add_timer_msec(master, nhrp_nhs_resolve, nhs, 1000,
+			      &nhs->t_resolve);
+
+	return NHRP_OK;
+}
+
+int nhrp_nhs_del(struct interface *ifp, afi_t afi, union sockunion *proto_addr,
+		 const char *nbma_fqdn)
+{
+	struct nhrp_interface *nifp = ifp->info;
+	struct nhrp_nhs *nhs;
+	int ret = NHRP_ERR_ENTRY_NOT_FOUND;
+
+	if (sockunion_family(proto_addr) != AF_UNSPEC
+	    && sockunion_family(proto_addr) != afi2family(afi))
+		return NHRP_ERR_PROTOCOL_ADDRESS_MISMATCH;
+
+	frr_each_safe (nhrp_nhslist, &nifp->afi[afi].nhslist_head, nhs) {
+		if (!sockunion_same(&nhs->proto_addr, proto_addr))
+			continue;
+		if (strcmp(nhs->nbma_fqdn, nbma_fqdn) != 0)
+			continue;
+
+		nhrp_nhs_free(nifp, afi, nhs);
+		ret = NHRP_OK;
+	}
+
+	return ret;
+}
+
+int nhrp_nhs_free(struct nhrp_interface *nifp, afi_t afi, struct nhrp_nhs *nhs)
+{
+	struct nhrp_registration *r;
+
+	frr_each_safe (nhrp_reglist, &nhs->reglist_head, r)
+		nhrp_reg_delete(r);
+	THREAD_OFF(nhs->t_resolve);
+	nhrp_nhslist_del(&nifp->afi[afi].nhslist_head, nhs);
+	free((void *)nhs->nbma_fqdn);
+	XFREE(MTYPE_NHRP_NHS, nhs);
+	return 0;
+}
+
+void nhrp_nhs_interface_del(struct interface *ifp)
+{
+	struct nhrp_interface *nifp = ifp->info;
+	struct nhrp_nhs *nhs;
+	afi_t afi;
+
+	for (afi = 0; afi < AFI_MAX; afi++) {
+		debugf(NHRP_DEBUG_COMMON, "Cleaning up nhs entries (%zu)",
+		       nhrp_nhslist_count(&nifp->afi[afi].nhslist_head));
+
+		frr_each_safe (nhrp_nhslist, &nifp->afi[afi].nhslist_head, nhs)
+			nhrp_nhs_free(nifp, afi, nhs);
+	}
+}
+
+void nhrp_nhs_terminate(void)
+{
+	struct vrf *vrf = vrf_lookup_by_id(VRF_DEFAULT);
+	struct interface *ifp;
+	struct nhrp_interface *nifp;
+	struct nhrp_nhs *nhs;
+	afi_t afi;
+
+	FOR_ALL_INTERFACES (vrf, ifp) {
+		nifp = ifp->info;
+		for (afi = 0; afi < AFI_MAX; afi++) {
+			frr_each_safe (nhrp_nhslist,
+				       &nifp->afi[afi].nhslist_head, nhs)
+				nhrp_nhs_free(nifp, afi, nhs);
+		}
+	}
+}
+
+void nhrp_nhs_foreach(struct interface *ifp, afi_t afi,
+		      void (*cb)(struct nhrp_nhs *, struct nhrp_registration *,
+				 void *),
+		      void *ctx)
+{
+	struct nhrp_interface *nifp = ifp->info;
+	struct nhrp_nhs *nhs;
+	struct nhrp_registration *reg;
+
+	frr_each (nhrp_nhslist, &nifp->afi[afi].nhslist_head, nhs) {
+		if (nhrp_reglist_count(&nhs->reglist_head)) {
+			frr_each (nhrp_reglist, &nhs->reglist_head, reg)
+				cb(nhs, reg, ctx);
+		} else
+			cb(nhs, 0, ctx);
+	}
+}
+
+int nhrp_nhs_match_ip(union sockunion *in_ip, struct nhrp_interface *nifp)
+{
+	int i;
+	struct nhrp_nhs *nhs;
+	struct nhrp_registration *reg;
+
+	for (i = 0; i < AFI_MAX; i++) {
+		frr_each (nhrp_nhslist, &nifp->afi[i].nhslist_head, nhs) {
+			if (!nhrp_reglist_count(&nhs->reglist_head))
+				continue;
+
+			frr_each (nhrp_reglist, &nhs->reglist_head, reg) {
+				if (!sockunion_cmp(in_ip,
+						   &reg->peer->vc->remote.nbma))
+					return 1;
+			}
+		}
+	}
+	return 0;
+}