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+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * ip4/packet.h: ip4 packet format
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef included_ip4_packet_h
+#define included_ip4_packet_h
+
+#include <vnet/ip/ip_packet.h> /* for ip_csum_t */
+#include <vnet/ip/tcp_packet.h> /* for tcp_header_t */
+#include <vppinfra/byte_order.h> /* for clib_net_to_host_u16 */
+
+/* IP4 address which can be accessed either as 4 bytes
+ or as a 32-bit number. */
+typedef union
+{
+ u8 data[4];
+ u32 data_u32;
+ /* Aliases. */
+ u8 as_u8[4];
+ u32 as_u32;
+} ip4_address_t;
+
+typedef struct
+{
+ /* IP address must be first for ip_interface_address_get_address() to work */
+ ip4_address_t ip4_addr;
+ u32 fib_index;
+} ip4_address_fib_t;
+
+always_inline void
+ip4_addr_fib_init (ip4_address_fib_t * addr_fib, ip4_address_t * address,
+ u32 fib_index)
+{
+ clib_memcpy (&addr_fib->ip4_addr, address, sizeof (addr_fib->ip4_addr));
+ addr_fib->fib_index = fib_index;
+}
+
+/* (src,dst) pair of addresses as found in packet header. */
+typedef struct
+{
+ ip4_address_t src, dst;
+} ip4_address_pair_t;
+
+/* If address is a valid netmask, return length of mask. */
+always_inline uword
+ip4_address_netmask_length (ip4_address_t * a)
+{
+ uword result = 0;
+ uword i;
+ for (i = 0; i < ARRAY_LEN (a->as_u8); i++)
+ {
+ switch (a->as_u8[i])
+ {
+ case 0xff:
+ result += 8;
+ break;
+ case 0xfe:
+ result += 7;
+ goto done;
+ case 0xfc:
+ result += 6;
+ goto done;
+ case 0xf8:
+ result += 5;
+ goto done;
+ case 0xf0:
+ result += 4;
+ goto done;
+ case 0xe0:
+ result += 3;
+ goto done;
+ case 0xc0:
+ result += 2;
+ goto done;
+ case 0x80:
+ result += 1;
+ goto done;
+ case 0x00:
+ result += 0;
+ goto done;
+ default:
+ /* Not a valid netmask mask. */
+ return ~0;
+ }
+ }
+done:
+ return result;
+}
+
+typedef union
+{
+ struct
+ {
+ /* 4 bit packet length (in 32bit units) and version VVVVLLLL.
+ e.g. for packets w/ no options ip_version_and_header_length == 0x45. */
+ u8 ip_version_and_header_length;
+
+ /* Type of service. */
+ u8 tos;
+
+ /* Total layer 3 packet length including this header. */
+ u16 length;
+
+ /* Fragmentation ID. */
+ u16 fragment_id;
+
+ /* 3 bits of flags and 13 bits of fragment offset (in units
+ of 8 byte quantities). */
+ u16 flags_and_fragment_offset;
+#define IP4_HEADER_FLAG_MORE_FRAGMENTS (1 << 13)
+#define IP4_HEADER_FLAG_DONT_FRAGMENT (1 << 14)
+#define IP4_HEADER_FLAG_CONGESTION (1 << 15)
+
+ /* Time to live decremented by router at each hop. */
+ u8 ttl;
+
+ /* Next level protocol packet. */
+ u8 protocol;
+
+ /* Checksum. */
+ u16 checksum;
+
+ /* Source and destination address. */
+ union
+ {
+ struct
+ {
+ ip4_address_t src_address, dst_address;
+ };
+ ip4_address_pair_t address_pair;
+ };
+ };
+
+ /* For checksumming we'll want to access IP header in word sized chunks. */
+ /* For 64 bit machines. */
+ /* *INDENT-OFF* */
+ CLIB_PACKED (struct {
+ u64 checksum_data_64[2];
+ u32 checksum_data_64_32[1];
+ });
+ /* *INDENT-ON* */
+
+ /* For 32 bit machines. */
+ /* *INDENT-OFF* */
+ CLIB_PACKED (struct {
+ u32 checksum_data_32[5];
+ });
+ /* *INDENT-ON* */
+} ip4_header_t;
+
+/* Value of ip_version_and_header_length for packets w/o options. */
+#define IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS \
+ ((4 << 4) | (sizeof (ip4_header_t) / sizeof (u32)))
+
+always_inline int
+ip4_get_fragment_offset (ip4_header_t * i)
+{
+ return clib_net_to_host_u16 (i->flags_and_fragment_offset) & 0x1fff;
+}
+
+always_inline int
+ip4_get_fragment_more (ip4_header_t * i)
+{
+ return clib_net_to_host_u16 (i->flags_and_fragment_offset) &
+ IP4_HEADER_FLAG_MORE_FRAGMENTS;
+}
+
+always_inline int
+ip4_is_fragment (ip4_header_t * i)
+{
+ return (i->flags_and_fragment_offset &
+ clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS));
+}
+
+always_inline int
+ip4_is_first_fragment (ip4_header_t * i)
+{
+ return (i->flags_and_fragment_offset &
+ clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS)) ==
+ clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
+}
+
+/* Fragment offset in bytes. */
+always_inline int
+ip4_get_fragment_offset_bytes (ip4_header_t * i)
+{
+ return 8 * ip4_get_fragment_offset (i);
+}
+
+always_inline int
+ip4_header_bytes (ip4_header_t * i)
+{
+ return sizeof (u32) * (i->ip_version_and_header_length & 0xf);
+}
+
+always_inline void *
+ip4_next_header (ip4_header_t * i)
+{
+ return (void *) i + ip4_header_bytes (i);
+}
+
+always_inline u16
+ip4_header_checksum (ip4_header_t * i)
+{
+ u16 save, csum;
+ ip_csum_t sum;
+
+ save = i->checksum;
+ i->checksum = 0;
+ sum = ip_incremental_checksum (0, i, ip4_header_bytes (i));
+ csum = ~ip_csum_fold (sum);
+
+ i->checksum = save;
+
+ /* Make checksum agree for special case where either
+ 0 or 0xffff would give same 1s complement sum. */
+ if (csum == 0 && save == 0xffff)
+ csum = save;
+
+ return csum;
+}
+
+static inline uword
+ip4_header_checksum_is_valid (ip4_header_t * i)
+{
+ return i->checksum == ip4_header_checksum (i);
+}
+
+#define ip4_partial_header_checksum_x1(ip0,sum0) \
+do { \
+ if (BITS (ip_csum_t) > 32) \
+ { \
+ sum0 = ip0->checksum_data_64[0]; \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
+ } \
+ else \
+ { \
+ sum0 = ip0->checksum_data_32[0]; \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
+ } \
+} while (0)
+
+#define ip4_partial_header_checksum_x2(ip0,ip1,sum0,sum1) \
+do { \
+ if (BITS (ip_csum_t) > 32) \
+ { \
+ sum0 = ip0->checksum_data_64[0]; \
+ sum1 = ip1->checksum_data_64[0]; \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
+ sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64[1]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
+ sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64_32[0]); \
+ } \
+ else \
+ { \
+ sum0 = ip0->checksum_data_32[0]; \
+ sum1 = ip1->checksum_data_32[0]; \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
+ sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[1]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
+ sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[2]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
+ sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[3]); \
+ sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
+ sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[4]); \
+ } \
+} while (0)
+
+always_inline uword
+ip4_address_is_multicast (ip4_address_t * a)
+{
+ return (a->data[0] & 0xf0) == 0xe0;
+}
+
+always_inline void
+ip4_multicast_address_set_for_group (ip4_address_t * a,
+ ip_multicast_group_t g)
+{
+ ASSERT ((u32) g < (1 << 28));
+ a->as_u32 = clib_host_to_net_u32 ((0xe << 28) + g);
+}
+
+always_inline void
+ip4_multicast_ethernet_address (u8 * ethernet_address, ip4_address_t * a)
+{
+ u8 *d = a->as_u8;
+
+ ethernet_address[0] = 0x01;
+ ethernet_address[1] = 0x00;
+ ethernet_address[2] = 0x5e;
+ ethernet_address[3] = d[1] & 0x7f;
+ ethernet_address[4] = d[2];
+ ethernet_address[5] = d[3];
+}
+
+always_inline void
+ip4_tcp_reply_x1 (ip4_header_t * ip0, tcp_header_t * tcp0)
+{
+ u32 src0, dst0;
+
+ src0 = ip0->src_address.data_u32;
+ dst0 = ip0->dst_address.data_u32;
+ ip0->src_address.data_u32 = dst0;
+ ip0->dst_address.data_u32 = src0;
+
+ src0 = tcp0->ports.src;
+ dst0 = tcp0->ports.dst;
+ tcp0->ports.src = dst0;
+ tcp0->ports.dst = src0;
+}
+
+always_inline void
+ip4_tcp_reply_x2 (ip4_header_t * ip0, ip4_header_t * ip1,
+ tcp_header_t * tcp0, tcp_header_t * tcp1)
+{
+ u32 src0, dst0, src1, dst1;
+
+ src0 = ip0->src_address.data_u32;
+ src1 = ip1->src_address.data_u32;
+ dst0 = ip0->dst_address.data_u32;
+ dst1 = ip1->dst_address.data_u32;
+ ip0->src_address.data_u32 = dst0;
+ ip1->src_address.data_u32 = dst1;
+ ip0->dst_address.data_u32 = src0;
+ ip1->dst_address.data_u32 = src1;
+
+ src0 = tcp0->ports.src;
+ src1 = tcp1->ports.src;
+ dst0 = tcp0->ports.dst;
+ dst1 = tcp1->ports.dst;
+ tcp0->ports.src = dst0;
+ tcp1->ports.src = dst1;
+ tcp0->ports.dst = src0;
+ tcp1->ports.dst = src1;
+}
+
+#endif /* included_ip4_packet_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */