hash: add support for hashing infra

Type: feature

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: I3652ae275385d9b1eb1b11f418e3a7e5fef2f556

1 files changed, 203 insertions, 0 deletions

diff --git a/src/vnet/hash/crc32_5tuple.c b/src/vnet/hash/crc32_5tuple.c
new file mode 100644
index 00000000000..69ee63a59df
--- /dev/null
+++ b/src/vnet/hash/crc32_5tuple.c
@@ -0,0 +1,203 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/ip/ip4_packet.h>
+#include <vnet/ip/ip6_packet.h>
+#include <vnet/ip/ip46_address.h>
+#include <vnet/udp/udp_packet.h>
+#include <vnet/hash/hash.h>
+#include <vppinfra/crc32.h>
+
+typedef union
+{
+  struct
+  {
+    ip46_address_t src_address;
+    ip46_address_t dst_address;
+    union
+    {
+      struct
+      {
+	u16 src_port;
+	u16 dst_port;
+      };
+      u32 l4_hdr;
+    };
+  };
+  u8 as_u8[36];
+} crc32c_5tuple_key_t;
+
+static const u8 l4_mask_bits[256] = {
+  [IP_PROTOCOL_ICMP] = 16,	[IP_PROTOCOL_IGMP] = 8,
+  [IP_PROTOCOL_TCP] = 32,	[IP_PROTOCOL_UDP] = 32,
+  [IP_PROTOCOL_IPSEC_ESP] = 32, [IP_PROTOCOL_IPSEC_AH] = 32,
+  [IP_PROTOCOL_ICMP6] = 16,
+};
+
+static_always_inline void
+compute_ip6_key (ip6_header_t *ip, crc32c_5tuple_key_t *k)
+{
+  u8 pr;
+
+  /* copy 32 bytes of ip6 src and dst addresses into hash_key_t */
+  clib_memcpy_fast ((u8 *) k, (u8 *) ip + 8, sizeof (ip6_address_t) * 2);
+  pr = ip->protocol;
+  /* write l4 header */
+  k->l4_hdr = *(u32 *) ip6_next_header (ip) & pow2_mask (l4_mask_bits[pr]);
+}
+
+static_always_inline void
+compute_ip4_key (ip4_header_t *ip, crc32c_5tuple_key_t *k)
+{
+  u8 pr;
+  u64 *key = (u64 *) k;
+  /* copy 8 bytes of ip src and dst addresses into hash_key_t */
+  key[0] = 0;
+  key[1] = 0;
+  key[2] = 0;
+  key[3] = *(u64 *) ((u8 *) ip + 12);
+  pr = ip->protocol;
+  /* write l4 header */
+  k->l4_hdr = *(u32 *) ip4_next_header (ip) & pow2_mask (l4_mask_bits[pr]);
+}
+static_always_inline void
+compute_ip_key (void *p, crc32c_5tuple_key_t *key)
+{
+  if ((((u8 *) p)[0] & 0xf0) == 0x40)
+    compute_ip4_key (p, key);
+  else if ((((u8 *) p)[0] & 0xf0) == 0x60)
+    compute_ip6_key (p, key);
+}
+
+void
+vnet_crc32c_5tuple_ip_func (void **p, u32 *hash, u32 n_packets)
+{
+  u32 n_left_from = n_packets;
+
+  while (n_left_from >= 8)
+    {
+      crc32c_5tuple_key_t key[4];
+
+      clib_prefetch_load (p[4]);
+      clib_prefetch_load (p[5]);
+      clib_prefetch_load (p[6]);
+      clib_prefetch_load (p[7]);
+
+      compute_ip_key (p[0], &key[0]);
+      compute_ip_key (p[1], &key[1]);
+      compute_ip_key (p[2], &key[2]);
+      compute_ip_key (p[3], &key[3]);
+
+      hash[0] = clib_crc32c (key[0].as_u8, sizeof (key[0]));
+      hash[1] = clib_crc32c (key[1].as_u8, sizeof (key[1]));
+      hash[2] = clib_crc32c (key[2].as_u8, sizeof (key[2]));
+      hash[3] = clib_crc32c (key[3].as_u8, sizeof (key[3]));
+
+      hash += 4;
+      n_left_from -= 4;
+      p += 4;
+    }
+
+  while (n_left_from > 0)
+    {
+      crc32c_5tuple_key_t key;
+
+      compute_ip_key (p[0], &key);
+
+      hash[0] = clib_crc32c (key.as_u8, sizeof (key));
+
+      hash += 1;
+      n_left_from -= 1;
+      p += 1;
+    }
+}
+
+static_always_inline void
+compute_ethernet_key (void *p, crc32c_5tuple_key_t *key)
+{
+  u16 ethertype = 0, l2hdr_sz = 0;
+
+  ethernet_header_t *eh = (ethernet_header_t *) p;
+  ethertype = clib_net_to_host_u16 (eh->type);
+  l2hdr_sz = sizeof (ethernet_header_t);
+
+  if (ethernet_frame_is_tagged (ethertype))
+    {
+      ethernet_vlan_header_t *vlan = (ethernet_vlan_header_t *) (eh + 1);
+
+      ethertype = clib_net_to_host_u16 (vlan->type);
+      l2hdr_sz += sizeof (*vlan);
+      while (ethernet_frame_is_tagged (ethertype))
+	{
+	  vlan++;
+	  ethertype = clib_net_to_host_u16 (vlan->type);
+	  l2hdr_sz += sizeof (*vlan);
+	}
+    }
+
+  if (ethertype == ETHERNET_TYPE_IP4)
+    {
+      ip4_header_t *ip4 = (ip4_header_t *) (p + l2hdr_sz);
+      compute_ip4_key (ip4, key);
+    }
+  else if (ethertype == ETHERNET_TYPE_IP6)
+    {
+      ip6_header_t *ip6 = (ip6_header_t *) (p + l2hdr_sz);
+      compute_ip6_key (ip6, key);
+    }
+}
+
+void
+vnet_crc32c_5tuple_ethernet_func (void **p, u32 *hash, u32 n_packets)
+{
+  u32 n_left_from = n_packets;
+
+  while (n_left_from >= 8)
+    {
+      crc32c_5tuple_key_t key[4];
+
+      clib_prefetch_load (p[4]);
+      clib_prefetch_load (p[5]);
+      clib_prefetch_load (p[6]);
+      clib_prefetch_load (p[7]);
+
+      compute_ethernet_key (p[0], &key[0]);
+      compute_ethernet_key (p[1], &key[1]);
+      compute_ethernet_key (p[2], &key[2]);
+      compute_ethernet_key (p[3], &key[3]);
+
+      hash[0] = clib_crc32c (key[0].as_u8, sizeof (key[0]));
+      hash[1] = clib_crc32c (key[1].as_u8, sizeof (key[1]));
+      hash[2] = clib_crc32c (key[2].as_u8, sizeof (key[2]));
+      hash[3] = clib_crc32c (key[3].as_u8, sizeof (key[3]));
+
+      hash += 4;
+      n_left_from -= 4;
+      p += 4;
+    }
+
+  while (n_left_from > 0)
+    {
+      crc32c_5tuple_key_t key;
+
+      compute_ethernet_key (p[0], &key);
+
+      hash[0] = clib_crc32c (key.as_u8, sizeof (key));
+
+      hash += 1;
+      n_left_from -= 1;
+      p += 1;
+    }
+}
+
+VNET_REGISTER_HASH_FUNCTION (crc32c_5tuple, static) = {
+  .name = "crc32c-5tuple",
+  .description = "IPv4/IPv6 header and TCP/UDP ports",
+  .priority = 50,
+  .function[VNET_HASH_FN_TYPE_ETHERNET] = vnet_crc32c_5tuple_ethernet_func,
+  .function[VNET_HASH_FN_TYPE_IP] = vnet_crc32c_5tuple_ip_func,
+};