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diff --git a/lib/src/common.h b/lib/src/common.h
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+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * 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.
+ */
+
+/**
+ * @file common.c
+ * @brief Common interfaces abstracting low-level platform.
+ * details.
+ *
+ * The role of this header file is to provide an uniform interface to the
+ * different platform on top of which we build the hICN interface:
+ *  - syntax helpers
+ *  - IP address management
+ *  - protocol definition
+ *  - ...
+ *
+ * The rationale is to leverage as much as possible platform-specific code,
+ * however some level of harmonization is needed to build code on top. Whenever
+ * possible, we align to VPP structure and naming.
+ */
+
+#ifndef HICN_COMMON_H
+#define HICN_COMMON_H
+
+#include <stdint.h>
+#include <assert.h>
+
+/* Concise type definitions */
+
+typedef uint64_t u64;
+typedef uint32_t u32;
+typedef uint16_t u16;
+typedef uint8_t u8;
+
+/*
+ * Code annotations
+ *
+ * NOTE: these are defined by default in VPP.
+ */
+
+#ifndef HICN_VPP_PLUGIN
+
+#define PREDICT_FALSE(x) (x)
+#define PREDICT_TRUE(x) (x)
+#define always_inline static inline
+#define static_always_inline static inline
+#define STRUCT_SIZE_OF(type, member) sizeof(((type *)0)->member)
+#define ASSERT
+
+#define STATIC_ASSERT(x)
+
+#endif /* ! HICN_VPP_PLUGIN */
+
+/*
+ * IP address types
+ */
+
+#ifdef HICN_VPP_PLUGIN
+
+#include <vnet/ip/ip4_packet.h>	// ip4_address_t
+#include <vnet/ip/ip6_packet.h>	// ip6_address_t
+
+#else
+
+#include <netinet/in.h>
+
+typedef union
+{
+  u32 as_u32;
+  struct in_addr as_inaddr;
+} ip4_address_t;
+
+typedef union
+{
+  u64 as_u64[2];
+  u32 as_u32[4];
+  u8 as_u8[16];
+  struct in6_addr as_in6addr;
+} ip6_address_t;
+
+typedef union
+{
+  struct
+  {
+    u32 pad[3];
+    ip4_address_t ip4;
+  };
+  ip6_address_t ip6;
+} ip46_address_t;
+
+#define ip46_address_is_ip4(ip46)       (((ip46)->pad[0] | (ip46)->pad[1] | (ip46)->pad[2]) == 0)
+
+#endif /* ! HICN_VPP_PLUGIN */
+
+/**
+ * @brief Returns the family of an IP address
+ * @param [in] ip_address - IP address in presentation format
+ * @return AF_INET or AF_INET6 if successful, -1 otherwise
+ */
+int get_addr_family (const char *ip_address);
+
+/*
+ * Checksum computation
+ *
+ * NOTE: VPP provides efficient (incremental) checksum computations
+ * that we reuse, and provide alternative implementation otherwise.
+ */
+
+#ifndef HICN_VPP_PLUGIN
+
+typedef u16 ip_csum_t;
+
+/*
+ * Checksum update (incremental and non-incremental)
+ *
+ * Those functions are already defined in VPP in vnet/ip/ip_packet.h, and we
+ * borrow this code here.
+ */
+
+static_always_inline u16
+ip_csum_fold (ip_csum_t c)
+{
+  /* Reduce to 16 bits. */
+#if 0				// uword_bits == 64
+  c = (c & (ip_csum_t) 0xffffffff) + (c >> (ip_csum_t) 32);
+  c = (c & 0xffff) + (c >> 16);
+#endif
+
+  c = (c & 0xffff) + (c >> 16);
+  c = (c & 0xffff) + (c >> 16);
+
+  return c;
+}
+
+static_always_inline ip_csum_t
+ip_csum_with_carry (ip_csum_t sum, ip_csum_t x)
+{
+  ip_csum_t t = sum + x;
+  return t + (t < x);
+}
+
+/* Update checksum changing field at even byte offset from x -> 0. */
+static_always_inline ip_csum_t
+ip_csum_add_even (ip_csum_t c, ip_csum_t x)
+{
+  ip_csum_t d;
+
+  d = c - x;
+
+  /* Fold in carry from high bit. */
+  d -= d > c;
+
+  return d;
+}
+
+/* Update checksum changing field at even byte offset from 0 -> x. */
+static_always_inline ip_csum_t
+ip_csum_sub_even (ip_csum_t c, ip_csum_t x)
+{
+  return ip_csum_with_carry (c, x);
+}
+
+u32 cumulative_hash32 (const void *data, size_t len, u32 lastValue);
+u32 hash32 (const void *data, size_t len);
+u64 cumulative_hash64 (const void *data, size_t len, u64 lastValue);
+u64 hash64 (const void *data, size_t len);
+void hicn_packet_dump (uint8_t * buffer, size_t len);
+
+#endif /* ! HICN_VPP_PLUGIN */
+
+/**
+ * @brief Computes buffer checksum
+ * @param [in] addr - Pointer to buffer start
+ * @param [in] size - Size of buffer
+ * @param [in] init - Checksum initial value
+ * @return Checksum of specified buffer
+ */
+always_inline u16
+csum (const void *addr, size_t size, u16 init)
+{
+  u32 sum = init;
+  const u16 *bytes = (u16 *) addr;
+
+  while (size > 1)
+    {
+      sum += *bytes++;
+      size -= sizeof (u16);
+    }
+  if (size)
+    {
+      sum += *(const u8 *) bytes;
+    }
+  sum = (sum >> 16) + (sum & 0xffff);
+  sum += (sum >> 16);
+
+  return (u16) ~ sum;
+}
+
+/*
+ * Useful aliases
+ */
+
+/* Symmetry with IPPROTO_ICMPV6 */
+#define IPPROTO_ICMPV4 IPPROTO_ICMP
+
+/*
+ * Query IP version from packet (either 4 or 6)
+ * (version is located as same offsets in both protocol headers)
+ */
+#define HICN_IP_VERSION(packet) ((hicn_header_t *)packet)->v4.ip.version
+
+#endif /* HICN_COMMON_H */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */