/* * Copyright (c) 2017 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 * @brief IPv4 to IPv6 translation */ #ifndef __included_ip4_to_ip6_h__ #define __included_ip4_to_ip6_h__ #include <vnet/ip/ip.h> /** * IPv4 to IPv6 set call back function type */ typedef int (*ip4_to_ip6_set_fn_t) (ip4_header_t * ip4, ip6_header_t * ip6, void *ctx); /* *INDENT-OFF* */ static u8 icmp_to_icmp6_updater_pointer_table[] = { 0, 1, 4, 4, ~0, ~0, ~0, ~0, 7, 6, ~0, ~0, 8, 8, 8, 8, 24, 24, 24, 24 }; /* *INDENT-ON* */ #define frag_id_4to6(id) (id) /** * @brief Get TCP/UDP port number or ICMP id from IPv4 packet. * * @param ip4 IPv4 header. * @param sender 1 get sender port, 0 get receiver port. * * @returns Port number on success, 0 otherwise. */ always_inline u16 ip4_get_port (ip4_header_t * ip, u8 sender) { if (ip->ip_version_and_header_length != 0x45 || ip4_get_fragment_offset (ip)) return 0; if (PREDICT_TRUE ((ip->protocol == IP_PROTOCOL_TCP) || (ip->protocol == IP_PROTOCOL_UDP))) { udp_header_t *udp = (void *) (ip + 1); return (sender) ? udp->src_port : udp->dst_port; } else if (ip->protocol == IP_PROTOCOL_ICMP) { icmp46_header_t *icmp = (void *) (ip + 1); if (icmp->type == ICMP4_echo_request || icmp->type == ICMP4_echo_reply) { return *((u16 *) (icmp + 1)); } else if (clib_net_to_host_u16 (ip->length) >= 64) { ip = (ip4_header_t *) (icmp + 2); if (PREDICT_TRUE ((ip->protocol == IP_PROTOCOL_TCP) || (ip->protocol == IP_PROTOCOL_UDP))) { udp_header_t *udp = (void *) (ip + 1); return (sender) ? udp->dst_port : udp->src_port; } else if (ip->protocol == IP_PROTOCOL_ICMP) { icmp46_header_t *icmp = (void *) (ip + 1); if (icmp->type == ICMP4_echo_request || icmp->type == ICMP4_echo_reply) { return *((u16 *) (icmp + 1)); } } } } return 0; } /** * @brief Convert type and code value from ICMP4 to ICMP6. * * @param icmp ICMP header. * @param inner_ip4 Inner IPv4 header if present, 0 otherwise. * * @returns 0 on success, non-zero value otherwise. */ always_inline int icmp_to_icmp6_header (icmp46_header_t * icmp, ip4_header_t ** inner_ip4) { *inner_ip4 = NULL; switch (icmp->type) { case ICMP4_echo_reply: icmp->type = ICMP6_echo_reply; break; case ICMP4_echo_request: icmp->type = ICMP6_echo_request; break; case ICMP4_destination_unreachable: *inner_ip4 = (ip4_header_t *) (((u8 *) icmp) + 8); switch (icmp->code) { case ICMP4_destination_unreachable_destination_unreachable_net: //0 case ICMP4_destination_unreachable_destination_unreachable_host: //1 icmp->type = ICMP6_destination_unreachable; icmp->code = ICMP6_destination_unreachable_no_route_to_destination; break; case ICMP4_destination_unreachable_protocol_unreachable: //2 icmp->type = ICMP6_parameter_problem; icmp->code = ICMP6_parameter_problem_unrecognized_next_header; break; case ICMP4_destination_unreachable_port_unreachable: //3 icmp->type = ICMP6_destination_unreachable; icmp->code = ICMP6_destination_unreachable_port_unreachable; break; case ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set: //4 icmp->type = ICMP6_packet_too_big; icmp->code = 0; { u32 advertised_mtu = clib_net_to_host_u32 (*((u32 *) (icmp + 1))); if (advertised_mtu) advertised_mtu += 20; else advertised_mtu = 1000; //FIXME ! (RFC 1191 - plateau value) //FIXME: = minimum(advertised MTU+20, MTU_of_IPv6_nexthop, (MTU_of_IPv4_nexthop)+20) *((u32 *) (icmp + 1)) = clib_host_to_net_u32 (advertised_mtu); } break; case ICMP4_destination_unreachable_source_route_failed: //5 case ICMP4_destination_unreachable_destination_network_unknown: //6 case ICMP4_destination_unreachable_destination_host_unknown: //7 case ICMP4_destination_unreachable_source_host_isolated: //8 case ICMP4_destination_unreachable_network_unreachable_for_type_of_service: //11 case ICMP4_destination_unreachable_host_unreachable_for_type_of_service: //12 icmp->type = ICMP6_destination_unreachable; icmp->code = ICMP6_destination_unreachable_no_route_to_destination; break; case ICMP4_destination_unreachable_network_administratively_prohibited: //9 case ICMP4_destination_unreachable_host_administratively_prohibited: //10 case ICMP4_destination_unreachable_communication_administratively_prohibited: //13 case ICMP4_destination_unreachable_precedence_cutoff_in_effect: //15 icmp->type = ICMP6_destination_unreachable; icmp->code = ICMP6_destination_unreachable_destination_administratively_prohibited; break; case ICMP4_destination_unreachable_host_precedence_violation: //14 default: return -1; } break; case ICMP4_time_exceeded: //11 *inner_ip4 = (ip4_header_t *) (((u8 *) icmp) + 8); icmp->type = ICMP6_time_exceeded; break; case ICMP4_parameter_problem: *inner_ip4 = (ip4_header_t *) (((u8 *) icmp) + 8); switch (icmp->code) { case ICMP4_parameter_problem_pointer_indicates_error: case ICMP4_parameter_problem_bad_length: icmp->type = ICMP6_parameter_problem; icmp->code = ICMP6_parameter_problem_erroneous_header_field; { u8 ptr = icmp_to_icmp6_updater_pointer_table[*((u8 *) (icmp + 1))]; if (ptr == 0xff) return -1; *((u32 *) (icmp + 1)) = clib_host_to_net_u32 (ptr); } break; default: //All other codes cause error return -1; } break; default: //All other types cause error return -1; break; } return 0; } /** * @brief Translate ICMP4 packet to ICMP6. * * @param p Buffer to translate. * @param fn The function to translate outer header. * @param ctx A context passed in the outer header translate function. * @param inner_fn The function to translate inner header. * @param inner_ctx A context passed in the inner header translate function. * * @returns 0 on success, non-zero value otherwise. */ always_inline int icmp_to_icmp6 (vlib_buffer_t * p, ip4_to_ip6_set_fn_t fn, void *ctx, ip4_to_ip6_set_fn_t inner_fn, void *inner_ctx) { ip4_header_t *ip4, *inner_ip4; ip6_header_t *ip6, *inner_ip6; u32 ip_len; icmp46_header_t *icmp; ip_csum_t csum; ip6_frag_hdr_t *inner_frag; u32 inner_frag_id; u32 inner_frag_offset; u8 inner_frag_more; u16 *inner_L4_checksum = 0; int rv; ip4 = vlib_buffer_get_current (p); ip_len = clib_net_to_host_u16 (ip4->length); ASSERT (ip_len <= p->current_length); icmp = (icmp46_header_t *) (ip4 + 1); if (icmp_to_icmp6_header (icmp, &inner_ip4)) return -1; if (inner_ip4) { //We have 2 headers to translate. //We need to make some room in the middle of the packet if (PREDICT_FALSE (ip4_is_fragment (inner_ip4))) { //Here it starts getting really tricky //We will add a fragmentation header in the inner packet if (!ip4_is_first_fragment (inner_ip4)) { //For now we do not handle unless it is the first fragment //Ideally we should handle the case as we are in slow path already return -1; } vlib_buffer_advance (p, -2 * (sizeof (*ip6) - sizeof (*ip4)) - sizeof (*inner_frag)); ip6 = vlib_buffer_get_current (p); clib_memcpy (u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4)), ip4, 20 + 8); ip4 = (ip4_header_t *) u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4)); icmp = (icmp46_header_t *) (ip4 + 1); inner_ip6 = (ip6_header_t *) u8_ptr_add (inner_ip4, sizeof (*ip4) - sizeof (*ip6) - sizeof (*inner_frag)); inner_frag = (ip6_frag_hdr_t *) u8_ptr_add (inner_ip6, sizeof (*inner_ip6)); ip6->payload_length = u16_net_add (ip4->length, sizeof (*ip6) - 2 * sizeof (*ip4) + sizeof (*inner_frag)); inner_frag_id = frag_id_4to6 (inner_ip4->fragment_id); inner_frag_offset = ip4_get_fragment_offset (inner_ip4); inner_frag_more = ! !(inner_ip4->flags_and_fragment_offset & clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS)); } else { vlib_buffer_advance (p, -2 * (sizeof (*ip6) - sizeof (*ip4))); ip6 = vlib_buffer_get_current (p); clib_memcpy (u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4)), ip4, 20 + 8); ip4 = (ip4_header_t *) u8_ptr_add (ip6, sizeof (*ip6) - sizeof (*ip4)); icmp = (icmp46_header_t *) u8_ptr_add (ip4, sizeof (*ip4)); inner_ip6 = (ip6_header_t *) u8_ptr_add (inner_ip4, sizeof (*ip4) - sizeof (*ip6)); ip6->payload_length = u16_net_add (ip4->length, sizeof (*ip6) - 2 * sizeof (*ip4)); inner_frag = NULL; } if (PREDICT_TRUE (inner_ip4->protocol == IP_PROTOCOL_TCP)) { inner_L4_checksum = &((tcp_header_t *) (inner_ip4 + 1))->checksum; *inner_L4_checksum = ip_csum_fold (ip_csum_sub_even (*inner_L4_checksum, *((u64 *) (&inner_ip4->src_address)))); } else if (PREDICT_TRUE (inner_ip4->protocol == IP_PROTOCOL_UDP)) { inner_L4_checksum = &((udp_header_t *) (inner_ip4 + 1))->checksum; if (*inner_L4_checksum) *inner_L4_checksum = ip_csum_fold (ip_csum_sub_even (*inner_L4_checksum, *((u64 *) (&inner_ip4->src_address)))); } else if (inner_ip4->protocol == IP_PROTOCOL_ICMP) { //We have an ICMP inside an ICMP //It needs to be translated, but not for error ICMP messages icmp46_header_t *inner_icmp = (icmp46_header_t *) (inner_ip4 + 1); //Only types ICMP4_echo_request and ICMP4_echo_reply are handled by icmp_to_icmp6_header inner_icmp->type = (inner_icmp->type == ICMP4_echo_request) ? ICMP6_echo_request : ICMP6_echo_reply; inner_L4_checksum = &inner_icmp->checksum; inner_ip4->protocol = IP_PROTOCOL_ICMP6; } else { /* To shut up Coverity */ os_panic (); } inner_ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 ((6 << 28) + (inner_ip4->tos << 20)); inner_ip6->payload_length = u16_net_add (inner_ip4->length, -sizeof (*inner_ip4)); inner_ip6->hop_limit = inner_ip4->ttl; inner_ip6->protocol = inner_ip4->protocol; if ((rv = inner_fn (inner_ip4, inner_ip6, inner_ctx)) != 0) return rv; if (PREDICT_FALSE (inner_frag != NULL)) { inner_frag->next_hdr = inner_ip6->protocol; inner_frag->identification = inner_frag_id; inner_frag->rsv = 0; inner_frag->fragment_offset_and_more = ip6_frag_hdr_offset_and_more (inner_frag_offset, inner_frag_more); inner_ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION; inner_ip6->payload_length = clib_host_to_net_u16 (clib_net_to_host_u16 (inner_ip6->payload_length) + sizeof (*inner_frag)); } csum = *inner_L4_checksum; if (inner_ip6->protocol == IP_PROTOCOL_ICMP6) { //Recompute ICMP checksum icmp46_header_t *inner_icmp = (icmp46_header_t *) (inner_ip4 + 1); inner_icmp->checksum = 0; csum = ip_csum_with_carry (0, inner_ip6->payload_length); csum = ip_csum_with_carry (csum, clib_host_to_net_u16 (inner_ip6->protocol)); csum = ip_csum_with_carry (csum, inner_ip6->src_address.as_u64[0]); csum = ip_csum_with_carry (csum, inner_ip6->src_address.as_u64[1]); csum = ip_csum_with_carry (csum, inner_ip6->dst_address.as_u64[0]); csum = ip_csum_with_carry (csum, inner_ip6->dst_address.as_u64[1]); csum = ip_incremental_checksum (csum, inner_icmp, clib_net_to_host_u16 (inner_ip6->payload_length)); inner_icmp->checksum = ~ip_csum_fold (csum); } else { /* UDP checksum is optional */ if (csum) { csum = ip_csum_add_even (csum, inner_ip6->src_address.as_u64[0]); csum = ip_csum_add_even (csum, inner_ip6->src_address.as_u64[1]); csum = ip_csum_add_even (csum, inner_ip6->dst_address.as_u64[0]); csum = ip_csum_add_even (csum, inner_ip6->dst_address.as_u64[1]); *inner_L4_checksum = ip_csum_fold (csum); } } } else { vlib_buffer_advance (p, sizeof (*ip4) - sizeof (*ip6)); ip6 = vlib_buffer_get_current (p); ip6->payload_length = clib_host_to_net_u16 (clib_net_to_host_u16 (ip4->length) - sizeof (*ip4)); } //Translate outer IPv6 ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 ((6 << 28) + (ip4->tos << 20)); ip6->hop_limit = ip4->ttl; ip6->protocol = IP_PROTOCOL_ICMP6; if ((rv = fn (ip4, ip6, ctx)) != 0) return rv; //Truncate when the packet exceeds the minimal IPv6 MTU if (p->current_length > 1280) { ip6->payload_length = clib_host_to_net_u16 (1280 - sizeof (*ip6)); p->current_length = 1280; //Looks too simple to be correct... } //Recompute ICMP checksum icmp->checksum = 0; csum = ip_csum_with_carry (0, ip6->payload_length); csum = ip_csum_with_carry (csum, clib_host_to_net_u16 (ip6->protocol)); csum = ip_csum_with_carry (csum, ip6->src_address.as_u64[0]); csum = ip_csum_with_carry (csum, ip6->src_address.as_u64[1]); csum = ip_csum_with_carry (csum, ip6->dst_address.as_u64[0]); csum = ip_csum_with_carry (csum, ip6->dst_address.as_u64[1]); csum = ip_incremental_checksum (csum, icmp, clib_net_to_host_u16 (ip6->payload_length)); icmp->checksum = ~ip_csum_fold (csum); return 0; } /** * @brief Translate IPv4 fragmented packet to IPv6. * * @param p Buffer to translate. * @param fn The function to translate header. * @param ctx A context passed in the header translate function. * * @returns 0 on success, non-zero value otherwise. */ always_inline int ip4_to_ip6_fragmented (vlib_buffer_t * p, ip4_to_ip6_set_fn_t fn, void *ctx) { ip4_header_t *ip4; ip6_header_t *ip6; ip6_frag_hdr_t *frag; int rv; ip4 = vlib_buffer_get_current (p); frag = (ip6_frag_hdr_t *) u8_ptr_add (ip4, sizeof (*ip4) - sizeof (*frag)); ip6 = (ip6_header_t *) u8_ptr_add (ip4, sizeof (*ip4) - sizeof (*frag) - sizeof (*ip6)); vlib_buffer_advance (p, sizeof (*ip4) - sizeof (*ip6) - sizeof (*frag)); //We know that the protocol was one of ICMP, TCP or UDP //because the first fragment was found and cached frag->next_hdr = (ip4->protocol == IP_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP6 : ip4->protocol; frag->identification = frag_id_4to6 (ip4->fragment_id); frag->rsv = 0; frag->fragment_offset_and_more = ip6_frag_hdr_offset_and_more (ip4_get_fragment_offset (ip4), clib_net_to_host_u16 (ip4->flags_and_fragment_offset) & IP4_HEADER_FLAG_MORE_FRAGMENTS); ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 ((6 << 28) + (ip4->tos << 20)); ip6->payload_length = clib_host_to_net_u16 (clib_net_to_host_u16 (ip4->length) - sizeof (*ip4) + sizeof (*frag)); ip6->hop_limit = ip4->ttl; ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION; if ((rv = fn (ip4, ip6, ctx)) != 0) return rv; return 0; } /** * @brief Translate IPv4 UDP/TCP packet to IPv6. * * @param p Buffer to translate. * @param fn The function to translate header. * @param ctx A context passed in the header translate function. * * @returns 0 on success, non-zero value otherwise. */ always_inline int ip4_to_ip6_tcp_udp (vlib_buffer_t * p, ip4_to_ip6_set_fn_t fn, void *ctx) { ip4_header_t *ip4; ip6_header_t *ip6; ip_csum_t csum; u16 *checksum; ip6_frag_hdr_t *frag; u32 frag_id; int rv; ip4 = vlib_buffer_get_current (p); if (ip4->protocol == IP_PROTOCOL_UDP) { udp_header_t *udp = ip4_next_header (ip4); checksum = &udp->checksum; //UDP checksum is optional over IPv4 but mandatory for IPv6 //We do not check udp->length sanity but use our safe computed value instead if (PREDICT_FALSE (!checksum)) { u16 udp_len = clib_host_to_net_u16 (ip4->length) - sizeof (*ip4); csum = ip_incremental_checksum (0, udp, udp_len); csum = ip_csum_with_carry (csum, clib_host_to_net_u16 (udp_len)); csum = ip_csum_with_carry (csum, clib_host_to_net_u16 (IP_PROTOCOL_UDP)); csum = ip_csum_with_carry (csum, *((u64 *) (&ip4->src_address))); *checksum = ~ip_csum_fold (csum); } } else { tcp_header_t *tcp = ip4_next_header (ip4); checksum = &tcp->checksum; } csum = ip_csum_sub_even (*checksum, ip4->src_address.as_u32); csum = ip_csum_sub_even (csum, ip4->dst_address.as_u32); *checksum = ip_csum_fold (csum); // Deal with fragmented packets if (PREDICT_FALSE (ip4->flags_and_fragment_offset & clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS))) { ip6 = (ip6_header_t *) u8_ptr_add (ip4, sizeof (*ip4) - sizeof (*ip6) - sizeof (*frag)); frag = (ip6_frag_hdr_t *) u8_ptr_add (ip4, sizeof (*ip4) - sizeof (*frag)); frag_id = frag_id_4to6 (ip4->fragment_id); vlib_buffer_advance (p, sizeof (*ip4) - sizeof (*ip6) - sizeof (*frag)); } else { ip6 = (ip6_header_t *) (((u8 *) ip4) + sizeof (*ip4) - sizeof (*ip6)); vlib_buffer_advance (p, sizeof (*ip4) - sizeof (*ip6)); frag = NULL; } ip6->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32 ((6 << 28) + (ip4->tos << 20)); ip6->payload_length = u16_net_add (ip4->length, -sizeof (*ip4)); ip6->hop_limit = ip4->ttl; ip6->protocol = ip4->protocol; if (PREDICT_FALSE (frag != NULL)) { frag->next_hdr = ip6->protocol; frag->identification = frag_id; frag->rsv = 0; frag->fragment_offset_and_more = ip6_frag_hdr_offset_and_more (0, 1); ip6->protocol = IP_PROTOCOL_IPV6_FRAGMENTATION; ip6->payload_length = u16_net_add (ip6->payload_length, sizeof (*frag)); } if ((rv = fn (ip4, ip6, ctx)) != 0) return rv; csum = ip_csum_add_even (*checksum, ip6->src_address.as_u64[0]); csum = ip_csum_add_even (csum, ip6->src_address.as_u64[1]); csum = ip_csum_add_even (csum, ip6->dst_address.as_u64[0]); csum = ip_csum_add_even (csum, ip6->dst_address.as_u64[1]); *checksum = ip_csum_fold (csum); return 0; } #endif /* __included_ip4_to_ip6_h__ */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */