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authorNeale Ranns <neale@graphiant.com>2020-12-21 08:29:34 +0000
committerOle Tr�an <otroan@employees.org>2021-02-15 17:27:48 +0000
commit8f5fef2c78b95de1a636ce27111722b71702212a (patch)
treea0ebd0189969ccae1f0bdd7c1a9c18dd7a066f2e /src/vnet/ip/ip_path_mtu.h
parent54be0cc044f445853fae7b8995c477605250af16 (diff)
ip: Path MTU
Type: feature Support setting the MTU for a peer on an interface. The minimum value of the path and interface MTU is used at forwarding time. the path MTU is specified for a given peer, by address and table-ID. In the forwarding plane the MTU is enfored either: 1 - if the peer is attached, then the MTU is set on the peer's adjacency 2 - if the peer is not attached, it is remote, then a DPO is added to the peer's FIB entry to perform the necessary fragmentation. Signed-off-by: Neale Ranns <neale@graphiant.com> Change-Id: I8b9ea6a07868b50e97e2561f18d9335407dea7ae
Diffstat (limited to 'src/vnet/ip/ip_path_mtu.h')
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1 files changed, 126 insertions, 0 deletions
diff --git a/src/vnet/ip/ip_path_mtu.h b/src/vnet/ip/ip_path_mtu.h
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+/*
+ *------------------------------------------------------------------
+ * ip_path_mtu.h
+ *
+ * Copyright (c) 2021 Graphiant.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#include <vnet/ip/ip.h>
+
+/**
+ * @brief
+ * The Path MTU DPO. interposed in the forwarding chain of the host prefix.
+ */
+typedef struct ip_pmtu_dpo_t_
+{
+ /**
+ * The protocol of packets using this DPO
+ */
+ dpo_proto_t ipm_proto;
+
+ u8 __pad8;
+
+ /**
+ * Configured Path Mtu
+ */
+ u16 ipm_pmtu;
+
+ /**
+ * number of locks.
+ */
+ u16 ipm_locks;
+
+ /**
+ * Stacked DPO
+ */
+ dpo_id_t ipm_dpo;
+} ip_pmtu_dpo_t;
+
+/*
+ * PMTU DPOs are accessed in the data-path so they should not straddle a cache
+ * line. Align to a integer factor of a cacheline
+ */
+STATIC_ASSERT_SIZEOF (ip_pmtu_dpo_t, 2 * sizeof (u64));
+
+#define foreach_ip_pmtu_flag \
+ _ (ATTACHED, 0, "attached") \
+ _ (REMOTE, 1, "remote") \
+ _ (STALE, 2, "stale")
+
+typedef enum ip_pmtu_flags_t_
+{
+#define _(a, b, c) IP_PMTU_FLAG_##a = (1 << b),
+ foreach_ip_pmtu_flag
+#undef _
+} ip_pmtu_flags_t;
+
+/**
+ * Remote Path MTU tracking object
+ */
+typedef struct ip_pmtu_t_
+{
+ /** linkage into the FIB graph */
+ fib_node_t ipt_node;
+
+ /** Track fib entry */
+ fib_node_index_t ipt_fib_entry;
+ u32 ipt_sibling;
+ ip_pmtu_flags_t ipt_flags;
+
+ /** Configured MTU */
+ u16 ipt_cfg_pmtu;
+
+ /** MTU from the parent MTU */
+ u16 ipt_parent_pmtu;
+
+ /** operational MTU; the minimum value of the cfg and parent MTU */
+ u16 ipt_oper_pmtu;
+} ip_pmtu_t;
+
+extern int ip_path_mtu_update (const ip_address_t *nh, u32 table_id, u16 pmtu);
+
+typedef walk_rc_t (*ip_path_mtu_walk_t) (index_t ipti, void *ctx);
+
+extern void ip_path_mtu_walk (ip_path_mtu_walk_t fn, void *ctx);
+extern int ip_path_mtu_replace_begin (void);
+extern int ip_path_mtu_replace_end (void);
+
+extern u32 ip_pmtu_get_table_id (const ip_pmtu_t *ipt);
+extern void ip_pmtu_get_ip (const ip_pmtu_t *ipt, ip_address_t *ip);
+
+/**
+ * Data-plane accessor functions
+ */
+extern ip_pmtu_dpo_t *ip_pmtu_dpo_pool;
+static_always_inline ip_pmtu_dpo_t *
+ip_pmtu_dpo_get (index_t index)
+{
+ return (pool_elt_at_index (ip_pmtu_dpo_pool, index));
+}
+
+extern ip_pmtu_t *ip_pmtu_pool;
+static_always_inline ip_pmtu_t *
+ip_path_mtu_get (index_t index)
+{
+ return (pool_elt_at_index (ip_pmtu_pool, index));
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */