/* * 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/tcp/tcp_packet.h> /* for tcp_header_t */ #include <vppinfra/byte_order.h> /* for clib_net_to_host_u16 */ #include <vppinfra/warnings.h> /* for WARN_OFF/WARN_ON macro */ /* 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]; u16 as_u16[2]; 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, const ip4_address_t * address, u32 fib_index) { clib_memcpy_fast (&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; typedef struct { ip4_address_t addr, mask; } ip4_address_and_mask_t; 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. */ ip_dscp_t 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))) #define IP4_ROUTER_ALERT_OPTION 20 always_inline u16 ip4_get_fragment_offset (const ip4_header_t * i) { return clib_net_to_host_u16 (i->flags_and_fragment_offset) & 0x1fff; } always_inline u16 ip4_get_fragment_more (const 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 (const 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 (const 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 (const ip4_header_t * i) { return 8 * ip4_get_fragment_offset (i); } always_inline int ip4_header_bytes (const 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); } /* Turn off array bounds check due to ip4_header_t option field operations. */ /* *INDENT-OFF* */ WARN_OFF(array-bounds) /* *INDENT-ON* */ static_always_inline u16 ip4_header_checksum_inline (ip4_header_t * i, int with_checksum) { int option_len = (i->ip_version_and_header_length & 0xf) - 5; uword sum = 0; #if uword_bits == 64 u32 *iphdr = (u32 *) i; sum += iphdr[0]; sum += iphdr[1]; sum += with_checksum ? iphdr[2] : *(u16 *) (iphdr + 2); /* skip checksum */ sum += iphdr[3]; sum += iphdr[4]; if (PREDICT_FALSE (option_len > 0)) switch (option_len) { case 10: sum += iphdr[14]; case 9: sum += iphdr[13]; case 8: sum += iphdr[12]; case 7: sum += iphdr[11]; case 6: sum += iphdr[10]; case 5: sum += iphdr[9]; case 4: sum += iphdr[8]; case 3: sum += iphdr[7]; case 2: sum += iphdr[6]; case 1: sum += iphdr[5]; default: break; } sum = ((u32) sum) + (sum >> 32); #else u16 *iphdr = (u16 *) i; sum += iphdr[0]; sum += iphdr[1]; sum += iphdr[2]; sum += iphdr[3]; sum += iphdr[4]; if (with_checksum) sum += iphdr[5]; sum += iphdr[6]; sum += iphdr[7]; sum += iphdr[8]; sum += iphdr[9]; if (PREDICT_FALSE (option_len > 0)) switch (option_len) { case 10: sum += iphdr[28]; sum += iphdr[29]; case 9: sum += iphdr[26]; sum += iphdr[27]; case 8: sum += iphdr[24]; sum += iphdr[25]; case 7: sum += iphdr[22]; sum += iphdr[23]; case 6: sum += iphdr[20]; sum += iphdr[21]; case 5: sum += iphdr[18]; sum += iphdr[19]; case 4: sum += iphdr[16]; sum += iphdr[17]; case 3: sum += iphdr[14]; sum += iphdr[15]; case 2: sum += iphdr[12]; sum += iphdr[13]; case 1: sum += iphdr[10]; sum += iphdr[11]; default: break; } #endif sum = ((u16) sum) + (sum >> 16); sum = ((u16) sum) + (sum >> 16); return ~((u16) sum); } /* *INDENT-OFF* */ WARN_ON(array-bounds) /* *INDENT-ON* */ always_inline u16 ip4_header_checksum (ip4_header_t * i) { return ip4_header_checksum_inline (i, /* with_checksum */ 0); } always_inline void ip4_header_set_dscp (ip4_header_t * ip4, ip_dscp_t dscp) { ip4->tos &= ~0xfc; /* not masking the dscp value to save th instruction * it shouldn't b necessary since the argument is an enum * whose range is therefore constrained in the CP. in the * DP it will have been taken from another packet, so again * constrained in value */ ip4->tos |= dscp << IP_PACKET_TC_FIELD_DSCP_BIT_SHIFT; } always_inline void ip4_header_set_ecn (ip4_header_t * ip4, ip_ecn_t ecn) { ip4->tos &= ~IP_PACKET_TC_FIELD_ECN_MASK; ip4->tos |= ecn; } always_inline void ip4_header_set_ecn_w_chksum (ip4_header_t * ip4, ip_ecn_t ecn) { ip_csum_t sum = ip4->checksum; u8 old = ip4->tos; u8 new = (old & ~IP_PACKET_TC_FIELD_ECN_MASK) | ecn; sum = ip_csum_update (sum, old, new, ip4_header_t, tos); ip4->checksum = ip_csum_fold (sum); ip4->tos = new; } always_inline ip_dscp_t ip4_header_get_dscp (const ip4_header_t * ip4) { return (ip4->tos >> IP_PACKET_TC_FIELD_DSCP_BIT_SHIFT); } always_inline ip_ecn_t ip4_header_get_ecn (const ip4_header_t * ip4) { return (ip4->tos & IP_PACKET_TC_FIELD_ECN_MASK); } always_inline void ip4_header_set_df (ip4_header_t * ip4) { ip4->flags_and_fragment_offset |= clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT); } always_inline void ip4_header_clear_df (ip4_header_t * ip4) { ip4->flags_and_fragment_offset &= ~clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT); } always_inline u8 ip4_header_get_df (const ip4_header_t * ip4) { return (! !(ip4->flags_and_fragment_offset & clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT))); } static inline uword ip4_header_checksum_is_valid (ip4_header_t * i) { return ip4_header_checksum_inline (i, /* with_checksum */ 1) == 0; } #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 (const ip4_address_t * a) { return (a->data[0] & 0xf0) == 0xe0; } always_inline uword ip4_address_is_global_broadcast (const ip4_address_t * a) { return (a->as_u32) == 0xffffffff; } 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, const ip4_address_t * a) { const 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->src; dst0 = tcp0->dst; tcp0->src = dst0; tcp0->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->src; src1 = tcp1->src; dst0 = tcp0->dst; dst1 = tcp1->dst; tcp0->src = dst0; tcp1->src = dst1; tcp0->dst = src0; tcp1->dst = src1; } #endif /* included_ip4_packet_h */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */