zebra: Add code to set SRv6 encap source addr in dplane

Add a bunch of set functions and associated data structure in
zebra_dplane to allow the configuration of the source address for SRv6
encap in the data plane.

Signed-off-by: Carmine Scarpitta <carmine.scarpitta@uniroma2.it>

zebra/dplane_fpm_nl.c

@@ -972,6 +972,7 @@ static int fpm_nl_enqueue(struct fpm_nl_ctx *fnc, struct zebra_dplane_ctx *ctx)
 	case DPLANE_OP_TC_FILTER_ADD:
 	case DPLANE_OP_TC_FILTER_DELETE:
 	case DPLANE_OP_TC_FILTER_UPDATE:
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
 	case DPLANE_OP_NONE:
 	case DPLANE_OP_STARTUP_STAGE:
 		break;

zebra/ge_netlink.c

@@ -111,6 +111,106 @@ int genl_resolve_family(const char *family)
 	return ge_netlink_talk(genl_parse_getfamily, &req.n, zns, false);
 }
 
+/*
+ * sr tunsrc change via netlink interface, using a dataplane context object
+ *
+ * Returns -1 on failure, 0 when the msg doesn't fit entirely in the buffer
+ * otherwise the number of bytes written to buf.
+ */
+ssize_t netlink_sr_tunsrc_set_msg_encode(int cmd, struct zebra_dplane_ctx *ctx,
+					 void *buf, size_t buflen)
+{
+	struct nlsock *nl;
+	const struct in6_addr *tunsrc_addr;
+	struct genl_request *req = buf;
+
+	if (seg6_genl_family < 0) {
+		zlog_err(
+			"Failed to set SRv6 source address: kernel does not support 'SEG6' Generic Netlink family.");
+		return -1;
+	}
+
+	tunsrc_addr = dplane_ctx_get_srv6_encap_srcaddr(ctx);
+	if (!tunsrc_addr)
+		return -1;
+
+	if (buflen < sizeof(*req))
+		return 0;
+
+	nl = kernel_netlink_nlsock_lookup(dplane_ctx_get_ns_sock(ctx));
+
+	memset(req, 0, sizeof(*req));
+
+	req->n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
+	req->n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
+
+	/* Prepare Netlink request to set tunsrc addr */
+	req->n.nlmsg_type = seg6_genl_family;
+	req->n.nlmsg_pid = nl->snl.nl_pid;
+
+	req->g.cmd = cmd;
+	req->g.version = SEG6_GENL_VERSION;
+
+	switch (cmd) {
+	case SEG6_CMD_SET_TUNSRC:
+		if (!nl_attr_put(&req->n, buflen, SEG6_ATTR_DST, tunsrc_addr,
+				 sizeof(struct in6_addr)))
+			return 0;
+		break;
+	default:
+		zlog_err("Unsupported command (%u)", cmd);
+		return -1;
+	}
+
+	return NLMSG_ALIGN(req->n.nlmsg_len);
+}
+
+ssize_t netlink_sr_tunsrc_set_msg_encoder(struct zebra_dplane_ctx *ctx,
+					  void *buf, size_t buflen)
+{
+	enum dplane_op_e op;
+	int cmd = 0;
+
+	op = dplane_ctx_get_op(ctx);
+
+	/* Call to netlink layer based on type of operation */
+	if (op == DPLANE_OP_SRV6_ENCAP_SRCADDR_SET) {
+		/* Validate */
+		if (dplane_ctx_get_srv6_encap_srcaddr(ctx) == NULL) {
+			if (IS_ZEBRA_DEBUG_KERNEL)
+				zlog_debug(
+					"sr tunsrc set failed: SRv6 encap source address not set");
+			return -1;
+		}
+
+		cmd = SEG6_CMD_SET_TUNSRC;
+	} else {
+		/* Invalid op */
+		zlog_err("Context received for kernel sr tunsrc update with incorrect OP code (%u)",
+			 op);
+		return -1;
+	}
+
+	return netlink_sr_tunsrc_set_msg_encode(cmd, ctx, buf, buflen);
+}
+
+enum netlink_msg_status
+netlink_put_sr_tunsrc_set_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx)
+{
+	enum dplane_op_e op;
+	struct zebra_ns *zns;
+	struct genl_request req;
+
+	op = dplane_ctx_get_op(ctx);
+	assert(op == DPLANE_OP_SRV6_ENCAP_SRCADDR_SET);
+
+	netlink_sr_tunsrc_set_msg_encoder(ctx, &req, sizeof(req));
+
+	zns = zebra_ns_lookup(dplane_ctx_get_ns_sock(ctx));
+
+	return ge_netlink_talk(netlink_talk_filter, &req.n, zns, false);
+}
+
 void ge_netlink_init(struct zebra_ns *zns)
 {
 	if (zns->ge_netlink_cmd.sock < 0)

zebra/ge_netlink.h

@@ -25,6 +25,15 @@ struct genl_request {
 };
 
 extern int genl_resolve_family(const char *family);
+extern ssize_t netlink_sr_tunsrc_set_msg_encode(int cmd,
+						struct zebra_dplane_ctx *ctx,
+						void *buf, size_t buflen);
+extern ssize_t netlink_sr_tunsrc_set_msg_encoder(struct zebra_dplane_ctx *ctx,
+						 void *buf, size_t buflen);
+struct nl_batch;
+extern enum netlink_msg_status
+netlink_put_sr_tunsrc_set_msg(struct nl_batch *bth,
+			      struct zebra_dplane_ctx *ctx);
 extern void ge_netlink_init(struct zebra_ns *zns);
 
 #ifdef __cplusplus

zebra/kernel_netlink.c

@@ -1648,6 +1648,9 @@ static enum netlink_msg_status nl_put_msg(struct nl_batch *bth,
 	case DPLANE_OP_TC_FILTER_DELETE:
 	case DPLANE_OP_TC_FILTER_UPDATE:
 		return netlink_put_tc_filter_update_msg(bth, ctx);
+
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
+		return netlink_put_sr_tunsrc_set_msg(bth, ctx);
 	}
 
 	return FRR_NETLINK_ERROR;

zebra/kernel_socket.c

@@ -1622,6 +1622,7 @@ void kernel_update_multi(struct dplane_ctx_list_head *ctx_list)
 		case DPLANE_OP_INTF_ADDR_ADD:
 		case DPLANE_OP_INTF_ADDR_DEL:
 		case DPLANE_OP_STARTUP_STAGE:
+		case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
 			zlog_err("Unhandled dplane data for %s",
 				 dplane_op2str(dplane_ctx_get_op(ctx)));
 			res = ZEBRA_DPLANE_REQUEST_FAILURE;

zebra/zebra_dplane.c

@@ -356,6 +356,13 @@ struct dplane_tc_filter_info {
 	uint32_t classid;
 };
 
+/*
+ * SRv6 encapsulation params context for the dataplane
+ */
+struct dplane_srv6_encap_ctx {
+	struct in6_addr srcaddr;
+};
+
 /*
  * The context block used to exchange info about route updates across
  * the boundary between the zebra main context (and pthread) and the
@@ -418,6 +425,7 @@ struct zebra_dplane_ctx {
 		struct dplane_gre_ctx gre;
 		struct dplane_netconf_info netconf;
 		enum zebra_dplane_startup_notifications spot;
+		struct dplane_srv6_encap_ctx srv6_encap;
 	} u;
 
 	/* Namespace info, used especially for netlink kernel communication */
@@ -599,6 +607,9 @@ static struct zebra_dplane_globals {
 	_Atomic uint32_t dg_tcs_in;
 	_Atomic uint32_t dg_tcs_errors;
 
+	_Atomic uint32_t dg_srv6_encap_srcaddr_set_in;
+	_Atomic uint32_t dg_srv6_encap_srcaddr_set_errors;
+
 	/* Dataplane pthread */
 	struct frr_pthread *dg_pthread;
 
@@ -861,6 +872,7 @@ static void dplane_ctx_free_internal(struct zebra_dplane_ctx *ctx)
 	case DPLANE_OP_GRE_SET:
 	case DPLANE_OP_INTF_NETCONFIG:
 	case DPLANE_OP_STARTUP_STAGE:
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
 		break;
 	}
 }
@@ -1186,6 +1198,11 @@ const char *dplane_op2str(enum dplane_op_e op)
 		break;
 	case DPLANE_OP_STARTUP_STAGE:
 		ret = "STARTUP_STAGE";
+		break;
+
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
+		ret = "SRV6_ENCAP_SRCADDR_SET";
+		break;
 	}
 
 	return ret;
@@ -2599,6 +2616,16 @@ const struct prefix *dplane_ctx_get_intf_addr(
 	return &(ctx->u.intf.prefix);
 }
 
+
+/* Accessors for SRv6 encapsulation source address information */
+const struct in6_addr *
+dplane_ctx_get_srv6_encap_srcaddr(const struct zebra_dplane_ctx *ctx)
+{
+	DPLANE_CTX_VALID(ctx);
+
+	return &(ctx->u.srv6_encap.srcaddr);
+}
+
 void dplane_ctx_set_intf_addr(struct zebra_dplane_ctx *ctx,
 			      const struct prefix *p)
 {
@@ -5872,6 +5899,60 @@ done:
 	return result;
 }
 
+/*
+ * Common helper api for SRv6 encapsulation source address set
+ */
+enum zebra_dplane_result
+dplane_srv6_encap_srcaddr_set(const struct in6_addr *addr, ns_id_t ns_id)
+{
+	enum zebra_dplane_result result = ZEBRA_DPLANE_REQUEST_FAILURE;
+	struct zebra_dplane_ctx *ctx = NULL;
+	enum dplane_op_e op = DPLANE_OP_SRV6_ENCAP_SRCADDR_SET;
+	int ret;
+	struct zebra_ns *zns;
+
+	if (!addr)
+		return result;
+
+	if (IS_ZEBRA_DEBUG_DPLANE_DETAIL) {
+		zlog_debug("init dplane ctx %s: addr %pI6", dplane_op2str(op),
+			   addr);
+	}
+
+	zns = zebra_ns_lookup(ns_id);
+	if (!zns)
+		return result;
+
+	ctx = dplane_ctx_alloc();
+
+	ctx->zd_op = op;
+	ctx->zd_status = ZEBRA_DPLANE_REQUEST_SUCCESS;
+
+	dplane_ctx_ns_init(ctx, zns, false);
+
+	/* Init the SRv6 encap source address specific data area */
+	memcpy(&ctx->u.srv6_encap.srcaddr, addr,
+	       sizeof(ctx->u.srv6_encap.srcaddr));
+
+	/* Update counter */
+	atomic_fetch_add_explicit(&zdplane_info.dg_srv6_encap_srcaddr_set_in, 1,
+				  memory_order_relaxed);
+
+	/* Enqueue context for processing */
+	ret = dplane_update_enqueue(ctx);
+
+	if (ret == AOK)
+		result = ZEBRA_DPLANE_REQUEST_QUEUED;
+	else {
+		atomic_fetch_add_explicit(&zdplane_info
+						   .dg_srv6_encap_srcaddr_set_errors,
+					  1, memory_order_relaxed);
+		if (ctx)
+			dplane_ctx_free(&ctx);
+	}
+	return result;
+}
+
 /*
  * Handler for 'show dplane'
  */
@@ -6597,6 +6678,12 @@ static void kernel_dplane_log_detail(struct zebra_dplane_ctx *ctx)
 	case DPLANE_OP_TC_FILTER_UPDATE:
 	case DPLANE_OP_STARTUP_STAGE:
 		break;
+
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
+		zlog_debug("Dplane SRv6 encap source address set op %s, addr %pI6",
+			   dplane_op2str(dplane_ctx_get_op(ctx)),
+			   &ctx->u.srv6_encap.srcaddr);
+		break;
 	}
 }
 
@@ -6767,6 +6854,13 @@ static void kernel_dplane_handle_result(struct zebra_dplane_ctx *ctx)
 	case DPLANE_OP_INTF_NETCONFIG:
 		break;
 
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
+		if (res != ZEBRA_DPLANE_REQUEST_SUCCESS)
+			atomic_fetch_add_explicit(&zdplane_info
+							   .dg_srv6_encap_srcaddr_set_errors,
+						  1, memory_order_relaxed);
+		break;
+
 	case DPLANE_OP_NONE:
 	case DPLANE_OP_STARTUP_STAGE:
 		if (res != ZEBRA_DPLANE_REQUEST_SUCCESS)

zebra/zebra_dplane.h

@@ -18,6 +18,7 @@
 #include "zebra/zserv.h"
 #include "zebra/zebra_mpls.h"
 #include "zebra/zebra_nhg.h"
+#include "zebra/ge_netlink.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -198,6 +199,9 @@ enum dplane_op_e {
 
 	/* Startup Control */
 	DPLANE_OP_STARTUP_STAGE,
+
+	/* Source address for SRv6 encapsulation */
+	DPLANE_OP_SRV6_ENCAP_SRCADDR_SET,
 };
 
 /*
@@ -664,6 +668,8 @@ bool dplane_ctx_intf_is_broadcast(const struct zebra_dplane_ctx *ctx);
 void dplane_ctx_intf_set_broadcast(struct zebra_dplane_ctx *ctx);
 const struct prefix *dplane_ctx_get_intf_addr(
 	const struct zebra_dplane_ctx *ctx);
+const struct in6_addr *
+dplane_ctx_get_srv6_encap_srcaddr(const struct zebra_dplane_ctx *ctx);
 void dplane_ctx_set_intf_addr(struct zebra_dplane_ctx *ctx,
 			      const struct prefix *p);
 bool dplane_ctx_intf_has_dest(const struct zebra_dplane_ctx *ctx);
@@ -992,6 +998,13 @@ enum zebra_dplane_result
 dplane_gre_set(struct interface *ifp, struct interface *ifp_link,
 	       unsigned int mtu, const struct zebra_l2info_gre *gre_info);
 
+/*
+ * Enqueue an SRv6 encap source address set
+ */
+enum zebra_dplane_result
+dplane_srv6_encap_srcaddr_set(const struct in6_addr *addr, ns_id_t ns_id);
+
+
 /* Forward ref of zebra_pbr_rule */
 struct zebra_pbr_rule;
 

zebra/zebra_rib.c

@@ -4961,6 +4961,7 @@ static void rib_process_dplane_results(struct event *thread)
 			case DPLANE_OP_BR_PORT_UPDATE:
 			case DPLANE_OP_NEIGH_TABLE_UPDATE:
 			case DPLANE_OP_GRE_SET:
+			case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
 			case DPLANE_OP_NONE:
 				break;
 			case DPLANE_OP_STARTUP_STAGE:

zebra/zebra_script.c

@@ -415,6 +415,7 @@ void lua_pushzebra_dplane_ctx(lua_State *L, const struct zebra_dplane_ctx *ctx)
 	case DPLANE_OP_TC_FILTER_UPDATE:
 		/* Not currently handled */
 	case DPLANE_OP_INTF_NETCONFIG: /*NYI*/
+	case DPLANE_OP_SRV6_ENCAP_SRCADDR_SET:
 	case DPLANE_OP_NONE:
 	case DPLANE_OP_STARTUP_STAGE:
 		break;