Mesh forwarding with proxy support.

* Modified HWMP PREP/PREQ to contain a proxy entry and also changed PREP
frame processing according to amendment as following:
        o Fixed PREP to always update/create if acceptance criteria is meet;
        o PREQ processing to reply if request is for a proxy entry that is
          proxied by us;
        o Removed hwmp_discover call from PREQ, because sending a PREP will
          build the forward path, and by receving and accepting a PREQ we
          have already built the reverse path (non-proactive code);
* Disabled code for pro-active in PREP for now (will make a separate patch for
pro-active HWMP routing later)
* Added proxy information for a Mesh route, mesh gate to use and proxy seqno;
* Modified ieee80211_encap according to amendment;
* Introduced Mesh control address extension enum and removed unused struct,
also rename some structure element names.
* Modified mesh_input and added mesh_recv_* that should verify and process mesh
data frames according to 9.32 Mesh forwarding framework in amendment;
* Modified mesh_decap accordingly to changes done in mesh control AE struct;

Approved by: adrian

1 files changed, 121 insertions, 63 deletions

diff --git a/sys/net80211/ieee80211_hwmp.c b/sys/net80211/ieee80211_hwmp.c
index 3be6551..334399e 100644
--- a/sys/net80211/ieee80211_hwmp.c
+++ b/sys/net80211/ieee80211_hwmp.c
@@ -143,6 +143,8 @@ typedef uint32_t ieee80211_hwmp_seq;
 #define	HWMP_SEQ_GT(a, b)	((int32_t)((a)-(b)) > 0)
 #define	HWMP_SEQ_GEQ(a, b)	((int32_t)((a)-(b)) >= 0)
 
+#define HWMP_SEQ_MAX(a, b)	(a > b ? a : b)
+
 /*
  * Private extension of ieee80211_mesh_route.
  */
@@ -866,7 +868,7 @@ hwmp_recv_preq(struct ieee80211vap *vap, struct ieee80211_node *ni,
     const struct ieee80211_frame *wh, const struct ieee80211_meshpreq_ie *preq)
 {
 	struct ieee80211_mesh_state *ms = vap->iv_mesh;
-	struct ieee80211_mesh_route *rt = NULL;
+	struct ieee80211_mesh_route *rt = NULL; /* pro-active code */
 	struct ieee80211_mesh_route *rtorig = NULL;
 	struct ieee80211_mesh_route *rttarg = NULL;
 	struct ieee80211_hwmp_route *hrorig = NULL;
@@ -963,31 +965,44 @@ hwmp_recv_preq(struct ieee80211vap *vap, struct ieee80211_node *ni,
 
 	/*
 	 * Check if the PREQ is addressed to us.
+	 * or a Proxy currently supplied by us.
 	 */
-	if (IEEE80211_ADDR_EQ(vap->iv_myaddr, PREQ_TADDR(0))) {
-		IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
-		    "reply to %6D", preq->preq_origaddr, ":");
+	if (IEEE80211_ADDR_EQ(vap->iv_myaddr, PREQ_TADDR(0)) ||
+	    (rttarg != NULL &&
+	    rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY &&
+	    rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_VALID)) {
 		/*
-		 * Build and send a PREP frame.
+		 * When we are the target we shall update our own HWMP seq
+		 * number with max of (current and preq->seq) + 1
 		 */
+		hs->hs_seq = HWMP_SEQ_MAX(hs->hs_seq, PREQ_TSEQ(0)) + 1;
+
 		prep.prep_flags = 0;
+		if (rttarg != NULL && /* if NULL it means we are the target */
+		    rttarg->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY) {
+			IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
+			    "reply for proxy %6D", rttarg->rt_dest, ":");
+			prep.prep_flags |= IEEE80211_MESHPREP_FLAGS_AE;
+			IEEE80211_ADDR_COPY(prep.prep_target_ext_addr,
+			    rttarg->rt_dest);
+			/* update proxy seqno to HWMP seqno */
+			rttarg->rt_ext_seq = hs->hs_seq;
+		}
+		/*
+		 * Build and send a PREP frame.
+		 */
 		prep.prep_hopcount = 0;
 		prep.prep_ttl = ms->ms_ttl;
 		IEEE80211_ADDR_COPY(prep.prep_targetaddr, vap->iv_myaddr);
-		prep.prep_targetseq = ++hs->hs_seq;
+		prep.prep_targetseq = hs->hs_seq;
 		prep.prep_lifetime = preq->preq_lifetime;
 		prep.prep_metric = IEEE80211_MESHLMETRIC_INITIALVAL;
 		IEEE80211_ADDR_COPY(prep.prep_origaddr, preq->preq_origaddr);
 		prep.prep_origseq = preq->preq_origseq;
+
+		IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
+		    "reply to %6D", preq->preq_origaddr, ":");
 		hwmp_send_prep(ni, vap->iv_myaddr, wh->i_addr2, &prep);
-		/*
-		 * Build the reverse path, if we don't have it already.
-		 */
-		rt = ieee80211_mesh_rt_find(vap, preq->preq_origaddr);
-		if (rt == NULL)
-			hwmp_discover(vap, preq->preq_origaddr, NULL);
-		else if ((rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID) == 0)
-			hwmp_discover(vap, rt->rt_dest, NULL);
 		return;
 	}
 	/*
@@ -1179,15 +1194,19 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 	struct ieee80211_mesh_state *ms = vap->iv_mesh;
 	struct ieee80211_hwmp_state *hs = vap->iv_hwmp;
 	struct ieee80211_mesh_route *rt = NULL;
+	struct ieee80211_mesh_route *rtorig = NULL;
+	struct ieee80211_mesh_route *rtext = NULL;
 	struct ieee80211_hwmp_route *hr;
 	struct ieee80211com *ic = vap->iv_ic;
 	struct ifnet *ifp = vap->iv_ifp;
 	struct mbuf *m, *next;
 	uint32_t metric = 0;
+	const uint8_t *addr;
 
 	/*
-	 * Acceptance criteria: if the corresponding PREQ was not generated
-	 * by us and forwarding is disabled, discard this PREP.
+	 * Acceptance criteria: If the corresponding PREP was not generated
+	 * by us or generated by an external mac that is proxied by us
+	 * and forwarding is disabled, discard this PREP.
 	 */
 	if (ni == vap->iv_bss ||
 	    ni->ni_mlstate != IEEE80211_NODE_MESH_ESTABLISHED)
@@ -1195,10 +1214,21 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 	if (!IEEE80211_ADDR_EQ(vap->iv_myaddr, prep->prep_origaddr) &&
 	    !(ms->ms_flags & IEEE80211_MESHFLAGS_FWD))
 		return;
+	rtorig = ieee80211_mesh_rt_find(vap, prep->prep_origaddr);
+	if (rtorig != NULL &&
+	    !(rtorig->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY)) {
+		IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
+		    "received PREP(%u) for an orig(%6D) not proxied by us",
+		    prep->prep_origseq, prep->prep_origaddr, ":");
+		return;
+	}
+
+	/* PREP ACCEPTED */
 
 	IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
 	    "received PREP from %6D", prep->prep_targetaddr, ":");
 
+#if 0
 	rt = ieee80211_mesh_rt_find(vap, prep->prep_targetaddr);
 	if (rt == NULL) {
 		/*
@@ -1228,10 +1258,30 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 		}
 		return;
 	}
+#endif
+
 	/*
-	 * Sequence number validation.
+	 * If accepted shall create or update the active forwarding information
+	 * it maintains for the target mesh STA of the PREP (according to the
+	 * rules defined in 13.10.8.4). If the conditions for creating or
+	 * updating the forwarding information have not been met in those
+	 * rules, no further steps are applied to the PREP.
+	 * [OPTIONAL]: update forwarding information to TA if metric improves.
 	 */
+	rt = ieee80211_mesh_rt_find(vap, prep->prep_targetaddr);
+	if (rt == NULL) {
+		rt = ieee80211_mesh_rt_add(vap, prep->prep_targetaddr);
+		if (rt == NULL) {
+			IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
+			    "unable to add PREP path to %6D",
+			    prep->prep_targetaddr, ":");
+			vap->iv_stats.is_mesh_rtaddfailed++;
+			return;
+		}
+	}
 	hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
+	/* update path metric */
+	metric = prep->prep_metric + ms->ms_pmetric->mpm_metric(ni);
 	if ((rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID)) {
 		if (HWMP_SEQ_LT(prep->prep_targetseq, hr->hr_seq)) {
 			IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
@@ -1240,7 +1290,7 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 			    prep->prep_targetseq, hr->hr_seq);
 			return;
 		} else if (HWMP_SEQ_LEQ(prep->prep_targetseq, hr->hr_seq) &&
-		    prep->prep_metric > rt->rt_metric) {
+		    metric > rt->rt_metric) {
 			IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
 			    "discard PREP from %6D, new metric %u > %u",
 			    prep->prep_targetaddr, ":",
@@ -1249,7 +1299,21 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 		}
 	}
 
+	IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
+	    "%s path to %6D, hopcount %d:%d metric %d:%d",
+	    rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID ?
+	    "prefer" : "update",
+	    prep->prep_targetaddr, ":",
+	    rt->rt_nhops, prep->prep_hopcount,
+	    rt->rt_metric, metric);
+
 	hr->hr_seq = prep->prep_targetseq;
+	IEEE80211_ADDR_COPY(rt->rt_nexthop, ni->ni_macaddr);
+	rt->rt_metric = metric;
+	rt->rt_nhops = prep->prep_hopcount + 1;
+	ieee80211_mesh_rt_update(rt, prep->prep_lifetime);
+	rt->rt_flags |= IEEE80211_MESHRT_FLAGS_VALID; /* mark valid */
+
 	/*
 	 * If it's NOT for us, propagate the PREP.
 	 */
@@ -1265,53 +1329,45 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 		pprep.prep_ttl -= 1;
 		pprep.prep_metric += ms->ms_pmetric->mpm_metric(ni);
 		hwmp_send_prep(ni, vap->iv_myaddr, broadcastaddr, &pprep);
+
+		/* may store target external address if recevied PREP w/ AE */
+		/* precursor list for the Target Mesh STA Address is updated */
 	}
-	hr = IEEE80211_MESH_ROUTE_PRIV(rt, struct ieee80211_hwmp_route);
-	if (rt->rt_flags & IEEE80211_MESHRT_FLAGS_PROXY) {
-		/* NB: never clobber a proxy entry */;
-		IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
-		    "discard PREP for %6D, route is marked PROXY",
-		    prep->prep_targetaddr, ":");
-		vap->iv_stats.is_hwmp_proxy++;
-	/* NB: first path discovery always fails */
-	} else if (hr->hr_origseq == 0 ||
-	    prep->prep_origseq == hr->hr_origseq) {
-		/*
-		 * Check if we already have a path to this node.
-		 * If we do, check if this path reply contains a
-		 * better route.
-		 */
-		if ((rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID) == 0 ||
-		    (prep->prep_hopcount < rt->rt_nhops ||
-		     prep->prep_metric < rt->rt_metric)) {
-			hr->hr_origseq = prep->prep_origseq;
-			metric = prep->prep_metric +
-			    ms->ms_pmetric->mpm_metric(ni);
-			IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
-			    "%s path to %6D, hopcount %d:%d metric %d:%d",
-			    rt->rt_flags & IEEE80211_MESHRT_FLAGS_VALID ?
-				"prefer" : "update",
-			    prep->prep_origaddr, ":",
-			    rt->rt_nhops, prep->prep_hopcount,
-			    rt->rt_metric, prep->prep_metric);
-			IEEE80211_ADDR_COPY(rt->rt_nexthop, wh->i_addr2);
-			rt->rt_nhops = prep->prep_hopcount + 1;
-			ieee80211_mesh_rt_update(rt, prep->prep_lifetime);
-			rt->rt_metric = metric;
-			rt->rt_flags |= IEEE80211_MESHRT_FLAGS_VALID;
-		} else {
-			IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
-			    "ignore PREP for %6D, hopcount %d:%d metric %d:%d",
-			    prep->prep_targetaddr, ":",
-			    rt->rt_nhops, prep->prep_hopcount,
-			    rt->rt_metric, prep->prep_metric);
+	/* check if we received a PREP for a proxy address */
+	else if (prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE) {
+		rtext = ieee80211_mesh_rt_find(vap,
+			prep->prep_target_ext_addr);
+		if (rtext == NULL) {
+			rtext = ieee80211_mesh_rt_add(vap,
+				prep->prep_target_ext_addr);
+			if (rtext == NULL) {
+				IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
+				    "unable to add PREP path to proxy %6D",
+				    prep->prep_targetaddr, ":");
+				vap->iv_stats.is_mesh_rtaddfailed++;
+				return;
+			}
 		}
-	} else {
 		IEEE80211_NOTE(vap, IEEE80211_MSG_HWMP, ni,
-		    "discard PREP for %6D, wrong orig seqno %u != %u",
-		    prep->prep_targetaddr, ":", prep->prep_origseq,
-		    hr->hr_origseq);
-		vap->iv_stats.is_hwmp_wrongseq++;
+		    "%s path to %6D, hopcount %d:%d metric %d:%d",
+		    rtext->rt_flags & IEEE80211_MESHRT_FLAGS_VALID ?
+		    "prefer" : "update",
+		    prep->prep_target_ext_addr, ":",
+		    rtext->rt_nhops, prep->prep_hopcount,
+		    rtext->rt_metric, metric);
+
+		rtext->rt_flags = IEEE80211_MESHRT_FLAGS_PROXY |
+			IEEE80211_MESHRT_FLAGS_VALID;
+		IEEE80211_ADDR_COPY(rtext->rt_dest,
+		    prep->prep_target_ext_addr);
+		IEEE80211_ADDR_COPY(rtext->rt_mesh_gate,
+		    prep->prep_targetaddr);
+		IEEE80211_ADDR_COPY(rtext->rt_nexthop, wh->i_addr2);
+		rtext->rt_metric = metric;
+		rtext->rt_lifetime = prep->prep_lifetime;
+		rtext->rt_nhops = prep->prep_hopcount + 1;
+		rtext->rt_ext_seq = prep->prep_origseq; /* proxy seq */
+		/* proxy entries have no HWMP priv data, nullify them to be sure? */
 	}
 	/*
 	 * Check for frames queued awaiting path discovery.
@@ -1320,9 +1376,11 @@ hwmp_recv_prep(struct ieee80211vap *vap, struct ieee80211_node *ni,
 	 *     stuck back on the stageq because there won't be
 	 *     a path.
 	 */
+	addr = prep->prep_flags & IEEE80211_MESHPREP_FLAGS_AE ?
+	    prep->prep_target_ext_addr : prep->prep_targetaddr;
 	m = ieee80211_ageq_remove(&ic->ic_stageq,
 	    (struct ieee80211_node *)(uintptr_t)
-	    ieee80211_mac_hash(ic, rt->rt_dest));
+	    ieee80211_mac_hash(ic, addr)); /* either dest or ext_dest */
 	for (; m != NULL; m = next) {
 		next = m->m_nextpkt;
 		m->m_nextpkt = NULL;