--- /dev/null
+/*
+ * 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)
+ {
+ return -1;
+ }
+ *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);
+ csum = inner_icmp->checksum;
+ //Only types ICMP4_echo_request and ICMP4_echo_reply are handled by icmp_to_icmp6_header
+ csum = ip_csum_sub_even (csum, *((u16 *) inner_icmp));
+ inner_icmp->type = (inner_icmp->type == ICMP4_echo_request) ?
+ ICMP6_echo_request : ICMP6_echo_reply;
+ csum = ip_csum_add_even (csum, *((u16 *) inner_icmp));
+ csum =
+ ip_csum_add_even (csum, clib_host_to_net_u16 (IP_PROTOCOL_ICMP6));
+ csum =
+ ip_csum_add_even (csum, inner_ip4->length - sizeof (*inner_ip4));
+ inner_icmp->checksum = ip_csum_fold (csum);
+ inner_L4_checksum = &inner_icmp->checksum;
+ inner_ip4->protocol = IP_PROTOCOL_ICMP6;
+ }
+ else
+ {
+ /* To shut up Coverity */
+ os_panic ();
+ }
+
+ csum = *inner_L4_checksum; //Initial checksum of the inner L4 header
+
+ 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 = 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);
+
+ // 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 (csum, 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:
+ */
Code Review / vpp.git / blobdiff