ospfd: Rework ospf_read_packet into 2 functions

The indentation level for ospf_read was starting to be pretty
extremene.  Rework into 2 functions for improved readability.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

ospfd/ospf_packet.c

@@ -2937,48 +2937,44 @@ static int ospf_verify_header(struct stream *ibuf, struct ospf_interface *oi,
 	return 0;
 }
 
-/* Starting point of packet process function. */
+enum ospf_read_return_enum {
-int ospf_read(struct thread *thread)
+	OSPF_READ_ERROR,
+	OSPF_READ_CONTINUE,
+};
+
+static enum ospf_read_return_enum ospf_read_helper(struct ospf *ospf)
 {
 	int ret;
 	struct stream *ibuf;
-	struct ospf *ospf;
 	struct ospf_interface *oi;
 	struct ip *iph;
 	struct ospf_header *ospfh;
 	uint16_t length;
-	struct interface *ifp = NULL;
 	struct connected *c;
-	int32_t count = 0;
+	struct interface *ifp = NULL;
 
-	/* first of all get interface pointer. */
-	ospf = THREAD_ARG(thread);
-
-	/* prepare for next packet. */
-	thread_add_read(master, ospf_read, ospf, ospf->fd, &ospf->t_read);
-
-	while (count < ospf->write_oi_count) {
-		count++;
 	stream_reset(ospf->ibuf);
 	ibuf = ospf_recv_packet(ospf, ospf->fd, &ifp, ospf->ibuf);
 	if (ibuf == NULL)
-			return -1;
+		return OSPF_READ_ERROR;
+
 	/*
 	 * This raw packet is known to be at least as big as its
-		 * IP header.
+	 * IP header. Note that there should not be alignment problems with
-		 * Note that there should not be alignment problems with
 	 * this assignment because this is at the beginning of the
 	 * stream data buffer.
 	 */
 	iph = (struct ip *)STREAM_DATA(ibuf);
-		/* Note that sockopt_iphdrincl_swab_systoh was called in
+	/*
-		 * ospf_recv_packet. */
+	 * Note that sockopt_iphdrincl_swab_systoh was called in
-
+	 * ospf_recv_packet.
+	 */
 	if (ifp == NULL) {
-			/* Handle cases where the platform does not support
+		/*
-			 * retrieving the ifindex, and also platforms (such
+		 * Handle cases where the platform does not support
-			 * as Solaris 8) that claim to support ifindex
+		 * retrieving the ifindex, and also platforms (such as
-			 * retrieval but do not.
+		 * Solaris 8) that claim to support ifindex retrieval but do
+		 * not.
 		 */
 		c = if_lookup_address((void *)&iph->ip_src, AF_INET,
 				      ospf->vrf_id);
@@ -2991,7 +2987,7 @@ int ospf_read(struct thread *thread)
 					__PRETTY_FUNCTION__,
 					inet_ntoa(iph->ip_src),
 					ospf_get_name(ospf));
-				continue;
+			return OSPF_READ_CONTINUE;
 		}
 	}
 
@@ -3002,7 +2998,7 @@ int ospf_read(struct thread *thread)
 				"ospf_read[%s]: Dropping self-originated packet",
 				inet_ntoa(iph->ip_src));
 		}
-			continue;
+		return OSPF_READ_CONTINUE;
 	}
 
 	/*
@@ -3013,20 +3009,21 @@ int ospf_read(struct thread *thread)
 
 	ospfh = (struct ospf_header *)stream_pnt(ibuf);
 	if (MSG_OK
-		    != ospf_packet_examin(ospfh,
+	    != ospf_packet_examin(ospfh, stream_get_endp(ibuf)
-					  stream_get_endp(ibuf)
 						 - stream_get_getp(ibuf)))
-			continue;
+		return OSPF_READ_CONTINUE;
 	/* Now it is safe to access all fields of OSPF packet header. */
 
 	/* associate packet with ospf interface */
 	oi = ospf_if_lookup_recv_if(ospf, iph->ip_src, ifp);
 
-		/* ospf_verify_header() relies on a valid "oi" and thus can
+	/*
-		 * be called only after the passive/backbone/other checks
+	 * ospf_verify_header() relies on a valid "oi" and thus can be called
-		 * below are passed. These checks in turn access the fields
+	 * only after the passive/backbone/other checks below are passed.
-		 * of unverified "ospfh" structure for their own purposes and
+	 * These checks in turn access the fields of unverified "ospfh"
-		 * must remain very accurate in doing this. */
+	 * structure for their own purposes and must remain very accurate
+	 * in doing this.
+	 */
 
 	/* If incoming interface is passive one, ignore it. */
 	if (oi && OSPF_IF_PASSIVE_STATUS(oi) == OSPF_IF_PASSIVE) {
@@ -3034,14 +3031,12 @@ int ospf_read(struct thread *thread)
 
 		if (IS_DEBUG_OSPF_EVENT)
 			zlog_debug(
-					"ignoring packet from router %s sent to %s, "
+				"ignoring packet from router %s sent to %s, received on a passive interface, %s",
-					"received on a passive interface, %s",
+				inet_ntop(AF_INET, &ospfh->router_id, buf[0],
-					inet_ntop(AF_INET, &ospfh->router_id,
+					  sizeof(buf[0])),
-						  buf[0], sizeof(buf[0])),
 				inet_ntop(AF_INET, &iph->ip_dst, buf[1],
 					  sizeof(buf[1])),
-					inet_ntop(AF_INET,
+				inet_ntop(AF_INET, &oi->address->u.prefix4,
-						  &oi->address->u.prefix4,
 					  buf[2], sizeof(buf[2])));
 
 		if (iph->ip_dst.s_addr == htonl(OSPF_ALLSPFROUTERS)) {
@@ -3052,7 +3047,7 @@ int ospf_read(struct thread *thread)
 			OI_MEMBER_JOINED(oi, MEMBER_ALLROUTERS);
 			ospf_if_set_multicast(oi);
 		}
-			continue;
+		return OSPF_READ_CONTINUE;
 	}
 
 
@@ -3063,16 +3058,13 @@ int ospf_read(struct thread *thread)
 	if ((oi == NULL)
 	    || (OSPF_IS_AREA_ID_BACKBONE(ospfh->area_id)
 		&& !OSPF_IS_AREA_ID_BACKBONE(oi->area->area_id))) {
-			if ((oi = ospf_associate_packet_vl(ospf, ifp, iph,
+		if ((oi = ospf_associate_packet_vl(ospf, ifp, iph, ospfh))
-							   ospfh))
 		    == NULL) {
 			if (!ospf->instance && IS_DEBUG_OSPF_EVENT)
 				zlog_debug(
-						"Packet from [%s] received on link %s"
+					"Packet from [%s] received on link %s but no ospf_interface",
-						" but no ospf_interface",
+					inet_ntoa(iph->ip_src), ifp->name);
-						inet_ntoa(iph->ip_src),
+			return OSPF_READ_CONTINUE;
-						ifp->name);
-				return 0;
 		}
 	}
 
@@ -3082,18 +3074,16 @@ int ospf_read(struct thread *thread)
 	 */
 	else if (oi->ifp != ifp) {
 		if (IS_DEBUG_OSPF_EVENT)
-				flog_warn(
+			flog_warn(EC_OSPF_PACKET,
-					EC_OSPF_PACKET,
 				  "Packet from [%s] received on wrong link %s",
 				  inet_ntoa(iph->ip_src), ifp->name);
-			continue;
+		return OSPF_READ_CONTINUE;
 	} else if (oi->state == ISM_Down) {
 		char buf[2][INET_ADDRSTRLEN];
 
 		flog_warn(
 			EC_OSPF_PACKET,
-				"Ignoring packet from %s to %s received on interface that is "
+			"Ignoring packet from %s to %s received on interface that is down [%s]; interface flags are %s",
-				"down [%s]; interface flags are %s",
 			inet_ntop(AF_INET, &iph->ip_src, buf[0],
 				  sizeof(buf[0])),
 			inet_ntop(AF_INET, &iph->ip_dst, buf[1],
@@ -3106,7 +3096,7 @@ int ospf_read(struct thread *thread)
 			OI_MEMBER_JOINED(oi, MEMBER_DROUTERS);
 		if (oi->multicast_memberships)
 			ospf_if_set_multicast(oi);
-			continue;
+		return OSPF_READ_CONTINUE;
 	}
 
 	/*
@@ -3122,12 +3112,11 @@ int ospf_read(struct thread *thread)
 			EC_OSPF_PACKET,
 			"Dropping packet for AllDRouters from [%s] via [%s] (ISM: %s)",
 			inet_ntoa(iph->ip_src), IF_NAME(oi),
-				lookup_msg(ospf_ism_state_msg, oi->state,
+			lookup_msg(ospf_ism_state_msg, oi->state, NULL));
-					   NULL));
 		/* Try to fix multicast membership. */
 		SET_FLAG(oi->multicast_memberships, MEMBER_DROUTERS);
 		ospf_if_set_multicast(oi);
-			continue;
+		return OSPF_READ_CONTINUE;
 	}
 
 	/* Verify more OSPF header fields. */
@@ -3138,7 +3127,7 @@ int ospf_read(struct thread *thread)
 				"ospf_read[%s]: Header check failed, "
 				"dropping.",
 				inet_ntoa(iph->ip_src));
-			continue;
+		return OSPF_READ_CONTINUE;
 	}
 
 	/* Show debug receiving packet. */
@@ -3150,8 +3139,7 @@ int ospf_read(struct thread *thread)
 		}
 
 		zlog_debug("%s received from [%s] via [%s]",
-				   lookup_msg(ospf_packet_type_str, ospfh->type,
+			   lookup_msg(ospf_packet_type_str, ospfh->type, NULL),
-					      NULL),
 			   inet_ntoa(ospfh->router_id), IF_NAME(oi));
 		zlog_debug(" src [%s],", inet_ntoa(iph->ip_src));
 		zlog_debug(" dst [%s]", inet_ntoa(iph->ip_dst));
@@ -3191,6 +3179,33 @@ int ospf_read(struct thread *thread)
 			IF_NAME(oi), ospf_get_name(ospf), ospfh->type);
 		break;
 	}
+
+	return OSPF_READ_CONTINUE;
+}
+
+/* Starting point of packet process function. */
+int ospf_read(struct thread *thread)
+{
+	struct ospf *ospf;
+	int32_t count = 0;
+	enum ospf_read_return_enum ret;
+
+	/* first of all get interface pointer. */
+	ospf = THREAD_ARG(thread);
+
+	/* prepare for next packet. */
+	thread_add_read(master, ospf_read, ospf, ospf->fd, &ospf->t_read);
+
+	while (count < ospf->write_oi_count) {
+		count++;
+		ret = ospf_read_helper(ospf);
+		switch (ret) {
+		case OSPF_READ_ERROR:
+			return -1;
+			break;
+		case OSPF_READ_CONTINUE:
+			break;
+		}
 	}
 
 	return 0;