1 files changed, 622 insertions, 0 deletions

diff --git a/zebra/zebra_fpm_netlink.c b/zebra/zebra_fpm_netlink.c
new file mode 100644
index 0000000..1279762
--- /dev/null
+++ b/zebra/zebra_fpm_netlink.c
@@ -0,0 +1,622 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Code for encoding/decoding FPM messages that are in netlink format.
+ *
+ * Copyright (C) 1997, 98, 99 Kunihiro Ishiguro
+ * Copyright (C) 2012 by Open Source Routing.
+ * Copyright (C) 2012 by Internet Systems Consortium, Inc. ("ISC")
+ */
+
+#include <zebra.h>
+
+#ifdef HAVE_NETLINK
+
+#include "log.h"
+#include "rib.h"
+#include "vty.h"
+#include "prefix.h"
+
+#include "zebra/zserv.h"
+#include "zebra/zebra_router.h"
+#include "zebra/zebra_dplane.h"
+#include "zebra/zebra_ns.h"
+#include "zebra/zebra_vrf.h"
+#include "zebra/kernel_netlink.h"
+#include "zebra/rt_netlink.h"
+#include "nexthop.h"
+
+#include "zebra/zebra_fpm_private.h"
+#include "zebra/zebra_vxlan_private.h"
+#include "zebra/interface.h"
+
+/*
+ * af_addr_size
+ *
+ * The size of an address in a given address family.
+ */
+static size_t af_addr_size(uint8_t af)
+{
+	switch (af) {
+
+	case AF_INET:
+		return 4;
+	case AF_INET6:
+		return 16;
+	default:
+		assert(0);
+		return 16;
+	}
+}
+
+/*
+ * We plan to use RTA_ENCAP_TYPE attribute for VxLAN encap as well.
+ * Currently, values 0 to 8 for this attribute are used by lwtunnel_encap_types
+ * So, we cannot use these values for VxLAN encap.
+ */
+enum fpm_nh_encap_type_t {
+	FPM_NH_ENCAP_NONE = 0,
+	FPM_NH_ENCAP_VXLAN = 100,
+	FPM_NH_ENCAP_MAX,
+};
+
+/*
+ * fpm_nh_encap_type_to_str
+ */
+static const char *fpm_nh_encap_type_to_str(enum fpm_nh_encap_type_t encap_type)
+{
+	switch (encap_type) {
+	case FPM_NH_ENCAP_NONE:
+		return "none";
+
+	case FPM_NH_ENCAP_VXLAN:
+		return "VxLAN";
+
+	case FPM_NH_ENCAP_MAX:
+		return "invalid";
+	}
+
+	return "invalid";
+}
+
+struct vxlan_encap_info_t {
+	vni_t vni;
+};
+
+enum vxlan_encap_info_type_t {
+	VXLAN_VNI = 0,
+};
+
+struct fpm_nh_encap_info_t {
+	enum fpm_nh_encap_type_t encap_type;
+	union {
+		struct vxlan_encap_info_t vxlan_encap;
+	};
+};
+
+/*
+ * netlink_nh_info
+ *
+ * Holds information about a single nexthop for netlink. These info
+ * structures are transient and may contain pointers into rib
+ * data structures for convenience.
+ */
+struct netlink_nh_info {
+	/* Weight of the nexthop ( for unequal cost ECMP ) */
+	uint8_t weight;
+	uint32_t if_index;
+	union g_addr *gateway;
+
+	/*
+	 * Information from the struct nexthop from which this nh was
+	 * derived. For debug purposes only.
+	 */
+	int recursive;
+	enum nexthop_types_t type;
+	struct fpm_nh_encap_info_t encap_info;
+};
+
+/*
+ * netlink_route_info
+ *
+ * A structure for holding information for a netlink route message.
+ */
+struct netlink_route_info {
+	uint32_t nlmsg_pid;
+	uint16_t nlmsg_type;
+	uint8_t rtm_type;
+	uint32_t rtm_table;
+	uint8_t rtm_protocol;
+	uint8_t af;
+	struct prefix *prefix;
+	uint32_t *metric;
+	unsigned int num_nhs;
+
+	/*
+	 * Nexthop structures
+	 */
+	struct netlink_nh_info nhs[MULTIPATH_NUM];
+	union g_addr *pref_src;
+};
+
+/*
+ * netlink_route_info_add_nh
+ *
+ * Add information about the given nexthop to the given route info
+ * structure.
+ *
+ * Returns true if a nexthop was added, false otherwise.
+ */
+static int netlink_route_info_add_nh(struct netlink_route_info *ri,
+				     struct nexthop *nexthop,
+				     struct route_entry *re)
+{
+	struct netlink_nh_info nhi;
+	union g_addr *src;
+	struct zebra_vrf *zvrf = NULL;
+	struct interface *ifp = NULL, *link_if = NULL;
+	struct zebra_if *zif = NULL;
+	vni_t vni = 0;
+
+	memset(&nhi, 0, sizeof(nhi));
+	src = NULL;
+
+	if (ri->num_nhs >= (int)array_size(ri->nhs))
+		return 0;
+
+	nhi.recursive = nexthop->rparent ? 1 : 0;
+	nhi.type = nexthop->type;
+	nhi.if_index = nexthop->ifindex;
+	nhi.weight = nexthop->weight;
+
+	if (nexthop->type == NEXTHOP_TYPE_IPV4
+	    || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX) {
+		nhi.gateway = &nexthop->gate;
+		if (nexthop->src.ipv4.s_addr != INADDR_ANY)
+			src = &nexthop->src;
+	}
+
+	if (nexthop->type == NEXTHOP_TYPE_IPV6
+	    || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) {
+		/* Special handling for IPv4 route with IPv6 Link Local next hop
+		 */
+		if (ri->af == AF_INET)
+			nhi.gateway = &ipv4ll_gateway;
+		else
+			nhi.gateway = &nexthop->gate;
+	}
+
+	if (nexthop->type == NEXTHOP_TYPE_IFINDEX) {
+		if (nexthop->src.ipv4.s_addr != INADDR_ANY)
+			src = &nexthop->src;
+	}
+
+	if (!nhi.gateway && nhi.if_index == 0)
+		return 0;
+
+	if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_EVPN)) {
+		nhi.encap_info.encap_type = FPM_NH_ENCAP_VXLAN;
+
+		/* Extract VNI id for the nexthop SVI interface */
+		zvrf = zebra_vrf_lookup_by_id(nexthop->vrf_id);
+		if (zvrf) {
+			ifp = if_lookup_by_index_per_ns(zvrf->zns,
+							nexthop->ifindex);
+			if (ifp) {
+				zif = (struct zebra_if *)ifp->info;
+				if (zif) {
+					if (IS_ZEBRA_IF_BRIDGE(ifp))
+						link_if = ifp;
+					else if (IS_ZEBRA_IF_VLAN(ifp))
+						link_if =
+						if_lookup_by_index_per_ns(
+							zvrf->zns,
+							zif->link_ifindex);
+					if (link_if)
+						vni = vni_id_from_svi(ifp,
+								      link_if);
+				}
+			}
+		}
+
+		nhi.encap_info.vxlan_encap.vni = vni;
+	}
+
+	/*
+	 * We have a valid nhi. Copy the structure over to the route_info.
+	 */
+	ri->nhs[ri->num_nhs] = nhi;
+	ri->num_nhs++;
+
+	if (src && !ri->pref_src)
+		ri->pref_src = src;
+
+	return 1;
+}
+
+/*
+ * netlink_proto_from_route_type
+ */
+static uint8_t netlink_proto_from_route_type(int type)
+{
+	return zebra2proto(type);
+}
+
+/*
+ * netlink_route_info_fill
+ *
+ * Fill out the route information object from the given route.
+ *
+ * Returns true on success and false on failure.
+ */
+static int netlink_route_info_fill(struct netlink_route_info *ri, int cmd,
+				   rib_dest_t *dest, struct route_entry *re)
+{
+	struct nexthop *nexthop;
+
+	memset(ri, 0, sizeof(*ri));
+
+	ri->prefix = rib_dest_prefix(dest);
+	ri->af = rib_dest_af(dest);
+
+	ri->nlmsg_pid = pid;
+
+	ri->nlmsg_type = cmd;
+	ri->rtm_protocol = RTPROT_UNSPEC;
+
+	/*
+	 * An RTM_DELROUTE need not be accompanied by any nexthops,
+	 * particularly in our communication with the FPM.
+	 */
+	if (cmd == RTM_DELROUTE && !re)
+		return 1;
+
+	if (!re) {
+		zfpm_debug("%s: Expected non-NULL re pointer", __func__);
+		return 0;
+	}
+
+	ri->rtm_table = re->table;
+
+	ri->rtm_protocol = netlink_proto_from_route_type(re->type);
+	ri->rtm_type = RTN_UNICAST;
+	ri->metric = &re->metric;
+
+	for (ALL_NEXTHOPS(re->nhe->nhg, nexthop)) {
+		if (ri->num_nhs >= zrouter.multipath_num)
+			break;
+
+		if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
+			continue;
+		if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_DUPLICATE))
+			continue;
+
+		if (nexthop->type == NEXTHOP_TYPE_BLACKHOLE) {
+			switch (nexthop->bh_type) {
+			case BLACKHOLE_ADMINPROHIB:
+				ri->rtm_type = RTN_PROHIBIT;
+				break;
+			case BLACKHOLE_REJECT:
+				ri->rtm_type = RTN_UNREACHABLE;
+				break;
+			case BLACKHOLE_NULL:
+			case BLACKHOLE_UNSPEC:
+				ri->rtm_type = RTN_BLACKHOLE;
+				break;
+			}
+		}
+
+		if ((cmd == RTM_NEWROUTE
+		     && CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE))
+		    || (cmd == RTM_DELROUTE
+			&& CHECK_FLAG(re->status, ROUTE_ENTRY_INSTALLED))) {
+			netlink_route_info_add_nh(ri, nexthop, re);
+		}
+	}
+
+	if (ri->num_nhs == 0) {
+		switch (ri->rtm_type) {
+		case RTN_PROHIBIT:
+		case RTN_UNREACHABLE:
+		case RTN_BLACKHOLE:
+			break;
+		default:
+			/* If there is no useful nexthop then return. */
+			zfpm_debug(
+				"netlink_encode_route(): No useful nexthop.");
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/*
+ * netlink_route_info_encode
+ *
+ * Returns the number of bytes written to the buffer. 0 or a negative
+ * value indicates an error.
+ */
+static int netlink_route_info_encode(struct netlink_route_info *ri,
+				     char *in_buf, size_t in_buf_len)
+{
+	size_t bytelen;
+	unsigned int nexthop_num = 0;
+	size_t buf_offset;
+	struct netlink_nh_info *nhi;
+	enum fpm_nh_encap_type_t encap;
+	struct rtattr *nest, *inner_nest;
+	struct rtnexthop *rtnh;
+	struct vxlan_encap_info_t *vxlan;
+	struct in6_addr ipv6;
+
+	struct {
+		struct nlmsghdr n;
+		struct rtmsg r;
+		char buf[1];
+	} * req;
+
+	req = (void *)in_buf;
+
+	buf_offset = ((char *)req->buf) - ((char *)req);
+
+	if (in_buf_len < buf_offset) {
+		assert(0);
+		return 0;
+	}
+
+	memset(req, 0, buf_offset);
+
+	bytelen = af_addr_size(ri->af);
+
+	req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+	req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST;
+	req->n.nlmsg_pid = ri->nlmsg_pid;
+	req->n.nlmsg_type = ri->nlmsg_type;
+	req->r.rtm_family = ri->af;
+
+	/*
+	 * rtm_table field is a uchar field which can accommodate table_id less
+	 * than 256.
+	 * To support table id greater than 255, if the table_id is greater than
+	 * 255, set rtm_table to RT_TABLE_UNSPEC and add RTA_TABLE attribute
+	 * with 32 bit value as the table_id.
+	 */
+	if (ri->rtm_table < 256)
+		req->r.rtm_table = ri->rtm_table;
+	else {
+		req->r.rtm_table = RT_TABLE_UNSPEC;
+		nl_attr_put32(&req->n, in_buf_len, RTA_TABLE, ri->rtm_table);
+	}
+
+	req->r.rtm_dst_len = ri->prefix->prefixlen;
+	req->r.rtm_protocol = ri->rtm_protocol;
+	req->r.rtm_scope = RT_SCOPE_UNIVERSE;
+
+	nl_attr_put(&req->n, in_buf_len, RTA_DST, &ri->prefix->u.prefix,
+		    bytelen);
+
+	req->r.rtm_type = ri->rtm_type;
+
+	/* Metric. */
+	if (ri->metric)
+		nl_attr_put32(&req->n, in_buf_len, RTA_PRIORITY, *ri->metric);
+
+	if (ri->num_nhs == 0)
+		goto done;
+
+	if (ri->num_nhs == 1) {
+		nhi = &ri->nhs[0];
+
+		if (nhi->gateway) {
+			if (nhi->type == NEXTHOP_TYPE_IPV4_IFINDEX
+			    && ri->af == AF_INET6) {
+				ipv4_to_ipv4_mapped_ipv6(&ipv6,
+							 nhi->gateway->ipv4);
+				nl_attr_put(&req->n, in_buf_len, RTA_GATEWAY,
+					    &ipv6, bytelen);
+			} else
+				nl_attr_put(&req->n, in_buf_len, RTA_GATEWAY,
+					    nhi->gateway, bytelen);
+		}
+
+		if (nhi->if_index) {
+			nl_attr_put32(&req->n, in_buf_len, RTA_OIF,
+				      nhi->if_index);
+		}
+
+		encap = nhi->encap_info.encap_type;
+		switch (encap) {
+		case FPM_NH_ENCAP_NONE:
+		case FPM_NH_ENCAP_MAX:
+			break;
+		case FPM_NH_ENCAP_VXLAN:
+			nl_attr_put16(&req->n, in_buf_len, RTA_ENCAP_TYPE,
+				      encap);
+			vxlan = &nhi->encap_info.vxlan_encap;
+			nest = nl_attr_nest(&req->n, in_buf_len, RTA_ENCAP);
+			nl_attr_put32(&req->n, in_buf_len, VXLAN_VNI,
+				      vxlan->vni);
+			nl_attr_nest_end(&req->n, nest);
+			break;
+		}
+
+		goto done;
+	}
+
+	/*
+	 * Multipath case.
+	 */
+	nest = nl_attr_nest(&req->n, in_buf_len, RTA_MULTIPATH);
+
+	for (nexthop_num = 0; nexthop_num < ri->num_nhs; nexthop_num++) {
+		rtnh = nl_attr_rtnh(&req->n, in_buf_len);
+		nhi = &ri->nhs[nexthop_num];
+
+		if (nhi->gateway)
+			nl_attr_put(&req->n, in_buf_len, RTA_GATEWAY,
+				    nhi->gateway, bytelen);
+
+		if (nhi->if_index) {
+			rtnh->rtnh_ifindex = nhi->if_index;
+		}
+
+		rtnh->rtnh_hops = nhi->weight;
+
+		encap = nhi->encap_info.encap_type;
+		switch (encap) {
+		case FPM_NH_ENCAP_NONE:
+		case FPM_NH_ENCAP_MAX:
+			break;
+		case FPM_NH_ENCAP_VXLAN:
+			nl_attr_put16(&req->n, in_buf_len, RTA_ENCAP_TYPE,
+				      encap);
+			vxlan = &nhi->encap_info.vxlan_encap;
+			inner_nest =
+				nl_attr_nest(&req->n, in_buf_len, RTA_ENCAP);
+			nl_attr_put32(&req->n, in_buf_len, VXLAN_VNI,
+				      vxlan->vni);
+			nl_attr_nest_end(&req->n, inner_nest);
+			break;
+		}
+
+		nl_attr_rtnh_end(&req->n, rtnh);
+	}
+
+	nl_attr_nest_end(&req->n, nest);
+	assert(nest->rta_len > RTA_LENGTH(0));
+
+done:
+
+	if (ri->pref_src) {
+		nl_attr_put(&req->n, in_buf_len, RTA_PREFSRC, ri->pref_src,
+			    bytelen);
+	}
+
+	assert(req->n.nlmsg_len < in_buf_len);
+	return req->n.nlmsg_len;
+}
+
+/*
+ * zfpm_log_route_info
+ *
+ * Helper function to log the information in a route_info structure.
+ */
+static void zfpm_log_route_info(struct netlink_route_info *ri,
+				const char *label)
+{
+	struct netlink_nh_info *nhi;
+	unsigned int i;
+	char buf[PREFIX_STRLEN];
+
+	zfpm_debug("%s : %s %pFX, Proto: %s, Metric: %u", label,
+		   nl_msg_type_to_str(ri->nlmsg_type), ri->prefix,
+		   nl_rtproto_to_str(ri->rtm_protocol),
+		   ri->metric ? *ri->metric : 0);
+
+	for (i = 0; i < ri->num_nhs; i++) {
+		nhi = &ri->nhs[i];
+
+		if (nhi->gateway) {
+			if (ri->af == AF_INET)
+				inet_ntop(AF_INET, nhi->gateway, buf,
+					  sizeof(buf));
+			else
+				inet_ntop(AF_INET6, nhi->gateway, buf,
+					  sizeof(buf));
+		} else
+			strlcpy(buf, "none", sizeof(buf));
+
+		zfpm_debug("  Intf: %u, Gateway: %s, Recursive: %s, Type: %s, Encap type: %s",
+			   nhi->if_index, buf, nhi->recursive ? "yes" : "no",
+			   nexthop_type_to_str(nhi->type),
+			   fpm_nh_encap_type_to_str(nhi->encap_info.encap_type)
+			   );
+	}
+}
+
+/*
+ * zfpm_netlink_encode_route
+ *
+ * Create a netlink message corresponding to the given route in the
+ * given buffer space.
+ *
+ * Returns the number of bytes written to the buffer. 0 or a negative
+ * value indicates an error.
+ */
+int zfpm_netlink_encode_route(int cmd, rib_dest_t *dest, struct route_entry *re,
+			      char *in_buf, size_t in_buf_len)
+{
+	struct netlink_route_info ri_space, *ri;
+
+	ri = &ri_space;
+
+	if (!netlink_route_info_fill(ri, cmd, dest, re))
+		return 0;
+
+	zfpm_log_route_info(ri, __func__);
+
+	return netlink_route_info_encode(ri, in_buf, in_buf_len);
+}
+
+/*
+ * zfpm_netlink_encode_mac
+ *
+ * Create a netlink message corresponding to the given MAC.
+ *
+ * Returns the number of bytes written to the buffer. 0 or a negative
+ * value indicates an error.
+ */
+int zfpm_netlink_encode_mac(struct fpm_mac_info_t *mac, char *in_buf,
+			    size_t in_buf_len)
+{
+	size_t buf_offset;
+
+	struct macmsg {
+		struct nlmsghdr hdr;
+		struct ndmsg ndm;
+		char buf[0];
+	} *req;
+	req = (void *)in_buf;
+
+	buf_offset = offsetof(struct macmsg, buf);
+	if (in_buf_len < buf_offset)
+		return 0;
+	memset(req, 0, buf_offset);
+
+	/* Construct nlmsg header */
+	req->hdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
+	req->hdr.nlmsg_type = CHECK_FLAG(mac->fpm_flags, ZEBRA_MAC_DELETE_FPM) ?
+				RTM_DELNEIGH : RTM_NEWNEIGH;
+	req->hdr.nlmsg_flags = NLM_F_REQUEST;
+	if (req->hdr.nlmsg_type == RTM_NEWNEIGH)
+		req->hdr.nlmsg_flags |= (NLM_F_CREATE | NLM_F_REPLACE);
+
+	/* Construct ndmsg */
+	req->ndm.ndm_family = AF_BRIDGE;
+	req->ndm.ndm_ifindex = mac->vxlan_if;
+
+	req->ndm.ndm_state = NUD_REACHABLE;
+	req->ndm.ndm_flags |= NTF_SELF | NTF_MASTER;
+	if (CHECK_FLAG(mac->zebra_flags,
+		(ZEBRA_MAC_STICKY | ZEBRA_MAC_REMOTE_DEF_GW)))
+		req->ndm.ndm_state |= NUD_NOARP;
+	else
+		req->ndm.ndm_flags |= NTF_EXT_LEARNED;
+
+	/* Add attributes */
+	nl_attr_put(&req->hdr, in_buf_len, NDA_LLADDR, &mac->macaddr, 6);
+	nl_attr_put(&req->hdr, in_buf_len, NDA_DST, &mac->r_vtep_ip, 4);
+	nl_attr_put32(&req->hdr, in_buf_len, NDA_MASTER, mac->svi_if);
+	nl_attr_put32(&req->hdr, in_buf_len, NDA_VNI, mac->vni);
+
+	assert(req->hdr.nlmsg_len < in_buf_len);
+
+	zfpm_debug("Tx %s family %s ifindex %u MAC %pEA DEST %pI4",
+		   nl_msg_type_to_str(req->hdr.nlmsg_type),
+		   nl_family_to_str(req->ndm.ndm_family), req->ndm.ndm_ifindex,
+		   &mac->macaddr, &mac->r_vtep_ip);
+
+	return req->hdr.nlmsg_len;
+}
+
+#endif /* HAVE_NETLINK */