hash: add support for hashing infra

Type: feature

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: I3652ae275385d9b1eb1b11f418e3a7e5fef2f556
diff --git a/src/vnet/CMakeLists.txt b/src/vnet/CMakeLists.txt
index 78a2ba7..6813330 100644
--- a/src/vnet/CMakeLists.txt
+++ b/src/vnet/CMakeLists.txt
@@ -882,6 +882,19 @@
 list(APPEND VNET_API_FILES ipfix-export/ipfix_export.api)
 
 ##############################################################################
+# HASH
+##############################################################################
+list(APPEND VNET_SOURCES
+  hash/hash.c
+  hash/cli.c
+  hash/crc32_5tuple.c
+)
+
+list(APPEND VNET_HEADERS
+  hash/hash.h
+)
+
+##############################################################################
 # GSO
 ##############################################################################
 list(APPEND VNET_SOURCES
diff --git a/src/vnet/hash/FEATURE.yaml b/src/vnet/hash/FEATURE.yaml
new file mode 100644
index 0000000..1e3d23e
--- /dev/null
+++ b/src/vnet/hash/FEATURE.yaml
@@ -0,0 +1,9 @@
+---
+name: Hash infrastructure
+maintainer: Mohsin Kazmi <sykazmi@cisco.com>, Damjan Marion <damarion@cisco.com>
+features:
+  - Ethernet
+  - IP
+description: "Hash infrastructure"
+state: development
+properties: [CLI]
diff --git a/src/vnet/hash/cli.c b/src/vnet/hash/cli.c
new file mode 100644
index 0000000..47d33b9
--- /dev/null
+++ b/src/vnet/hash/cli.c
@@ -0,0 +1,33 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/hash/hash.h>
+
+static clib_error_t *
+show_hash (vlib_main_t *vm, unformat_input_t *input, vlib_cli_command_t *cmd)
+{
+  clib_error_t *error = 0;
+  vnet_hash_main_t *hm = &vnet_hash_main;
+  vnet_hash_function_registration_t *hash;
+
+  hash = hm->hash_registrations;
+
+  vlib_cli_output (vm, "%-25s%-8s%s", "Name", "Prio", "Description");
+  while (hash)
+    {
+      vlib_cli_output (vm, "%-25s%-8u%s", hash->name, hash->priority,
+		       hash->description);
+      hash = hash->next;
+    }
+
+  return (error);
+}
+
+VLIB_CLI_COMMAND (cmd_show_hash, static) = {
+  .path = "show hash",
+  .short_help = "show hash",
+  .function = show_hash,
+};
diff --git a/src/vnet/hash/crc32_5tuple.c b/src/vnet/hash/crc32_5tuple.c
new file mode 100644
index 0000000..69ee63a
--- /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,
+};
diff --git a/src/vnet/hash/hash.c b/src/vnet/hash/hash.c
new file mode 100644
index 0000000..31693c9
--- /dev/null
+++ b/src/vnet/hash/hash.c
@@ -0,0 +1,76 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/interface.h>
+#include <vnet/hash/hash.h>
+
+vnet_hash_main_t vnet_hash_main;
+
+u8 *
+format_vnet_hash (u8 *s, va_list *args)
+{
+  vnet_hash_function_registration_t *hash =
+    va_arg (*args, vnet_hash_function_registration_t *);
+
+  s = format (s, "[name: %s ", hash->name);
+  s = format (s, "priority: %u ", hash->priority);
+  s = format (s, "description: %s]", hash->description);
+  return s;
+}
+
+/**
+ * select hash func with highest priority
+ */
+vnet_hash_fn_t
+vnet_hash_default_function (vnet_hash_fn_type_t ftype)
+{
+  vnet_hash_function_registration_t *hash = vnet_hash_main.hash_registrations;
+  vnet_hash_function_registration_t *tmp_hash = hash;
+  while (hash)
+    {
+      if (hash->priority > tmp_hash->priority)
+	tmp_hash = hash;
+      hash = hash->next;
+    }
+  return tmp_hash->function[ftype];
+}
+
+vnet_hash_fn_t
+vnet_hash_function_from_name (const char *name, vnet_hash_fn_type_t ftype)
+{
+  vnet_hash_function_registration_t *hash = vnet_hash_main.hash_registrations;
+  while (hash)
+    {
+      if (strcmp (hash->name, name) == 0)
+	break;
+      hash = hash->next;
+    }
+  if (!hash)
+    return (0);
+  return hash->function[ftype];
+}
+
+vnet_hash_function_registration_t *
+vnet_hash_function_from_func (vnet_hash_fn_t fn, vnet_hash_fn_type_t ftype)
+{
+  vnet_hash_function_registration_t *hash = vnet_hash_main.hash_registrations;
+  while (hash)
+    {
+      if (hash->function[ftype] == fn)
+	break;
+      hash = hash->next;
+    }
+  return hash;
+}
+
+static clib_error_t *
+vnet_hash_init (vlib_main_t *vm)
+{
+  return (0);
+}
+
+VLIB_INIT_FUNCTION (vnet_hash_init);
diff --git a/src/vnet/hash/hash.h b/src/vnet/hash/hash.h
new file mode 100644
index 0000000..c1eb947
--- /dev/null
+++ b/src/vnet/hash/hash.h
@@ -0,0 +1,59 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#ifndef __VNET_HASH_H__
+#define __VNET_HASH_H__
+
+#include <vlib/vlib.h>
+
+#define foreach_vnet_hash_fn_types                                            \
+  _ (ETHERNET, 0, "hash-fn-ethernet")                                         \
+  _ (IP, 1, "hash-fn-ip")
+
+typedef enum
+{
+#define _(f, n, s) VNET_HASH_FN_TYPE_##f,
+  foreach_vnet_hash_fn_types
+#undef _
+    VNET_HASH_FN_TYPE_N,
+} vnet_hash_fn_type_t;
+
+typedef void (*vnet_hash_fn_t) (void **p, u32 *h, u32 n_packets);
+
+typedef struct vnet_hash_function_registration
+{
+  const char *name;
+  const char *description;
+  int priority;
+  vnet_hash_fn_t function[VNET_HASH_FN_TYPE_N];
+
+  struct vnet_hash_function_registration *next;
+} vnet_hash_function_registration_t;
+
+typedef struct
+{
+  vnet_hash_function_registration_t *hash_registrations;
+} vnet_hash_main_t;
+
+extern vnet_hash_main_t vnet_hash_main;
+
+#define VNET_REGISTER_HASH_FUNCTION(x, ...)                                   \
+  __VA_ARGS__ vnet_hash_function_registration_t __vnet_hash_function_##x;     \
+  static void __clib_constructor __vnet_hash_function_registration_##x (void) \
+  {                                                                           \
+    vnet_hash_main_t *hm = &vnet_hash_main;                                   \
+    __vnet_hash_function_##x.next = hm->hash_registrations;                   \
+    hm->hash_registrations = &__vnet_hash_function_##x;                       \
+  }                                                                           \
+  __VA_ARGS__ vnet_hash_function_registration_t __vnet_hash_function_##x
+
+vnet_hash_fn_t vnet_hash_default_function (vnet_hash_fn_type_t ftype);
+vnet_hash_fn_t vnet_hash_function_from_name (const char *name,
+					     vnet_hash_fn_type_t ftype);
+vnet_hash_function_registration_t *
+vnet_hash_function_from_func (vnet_hash_fn_t fn, vnet_hash_fn_type_t ftype);
+format_function_t format_vnet_hash;
+
+#endif