diff options
Diffstat (limited to 'src/plugins/snat/nat64_in2out.c')
| -rw-r--r-- | src/plugins/snat/nat64_in2out.c | 338 |
1 files changed, 335 insertions, 3 deletions
diff --git a/src/plugins/snat/nat64_in2out.c b/src/plugins/snat/nat64_in2out.c index eba69326..fd32bfc5 100644 --- a/src/plugins/snat/nat64_in2out.c +++ b/src/plugins/snat/nat64_in2out.c @@ -21,6 +21,15 @@ #include <vnet/ip/ip6_to_ip4.h> #include <vnet/fib/fib_table.h> +/* *INDENT-OFF* */ +static u8 well_known_prefix[] = { + 0x00, 0x64, 0xff, 0x9b, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00 +}; +/* *INDENT-ON* */ + typedef struct { u32 sw_if_index; @@ -65,7 +74,8 @@ static char *nat64_in2out_error_strings[] = { typedef enum { - NAT64_IN2OUT_NEXT_LOOKUP, + NAT64_IN2OUT_NEXT_IP4_LOOKUP, + NAT64_IN2OUT_NEXT_IP6_LOOKUP, NAT64_IN2OUT_NEXT_DROP, NAT64_IN2OUT_N_NEXT, } nat64_in2out_next_t; @@ -76,6 +86,31 @@ typedef struct nat64_in2out_set_ctx_t_ vlib_main_t *vm; } nat64_in2out_set_ctx_t; +/** + * @brief Check whether is a hairpinning. + * + * If the destination IP address of the packet is an IPv4 address assigned to + * the NAT64 itself, then the packet is a hairpin packet. + * + * param dst_addr Destination address of the packet. + * + * @returns 1 if hairpinning, otherwise 0. + */ +static_always_inline int +is_hairpinning (ip6_address_t * dst_addr) +{ + nat64_main_t *nm = &nat64_main; + int i; + + for (i = 0; i < vec_len (nm->addr_pool); i++) + { + if (nm->addr_pool[i].addr.as_u32 == dst_addr->as_u32[3]) + return 1; + } + + return 0; +} + static int nat64_in2out_tcp_udp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, void *arg) @@ -145,6 +180,18 @@ nat64_in2out_tcp_udp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, ip4->dst_address.as_u32 = daddr.ip4.as_u32; + if (proto == SNAT_PROTOCOL_TCP) + { + u16 *checksum; + ip_csum_t csum; + tcp_header_t *tcp = ip6_next_header (ip6); + + checksum = &tcp->checksum; + csum = ip_csum_sub_even (*checksum, sport); + csum = ip_csum_add_even (csum, udp->src_port); + *checksum = ip_csum_fold (csum); + } + return 0; } @@ -279,6 +326,10 @@ nat64_in2out_inner_icmp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, else { udp_header_t *udp = ip6_next_header (ip6); + tcp_header_t *tcp = ip6_next_header (ip6); + u16 *checksum; + ip_csum_t csum; + u16 sport = udp->src_port; u16 dport = udp->dst_port; @@ -295,11 +346,267 @@ nat64_in2out_inner_icmp_set_cb (ip6_header_t * ip6, ip4_header_t * ip4, ip4->dst_address.as_u32 = bibe->out_addr.as_u32; udp->dst_port = bibe->out_port; ip4->src_address.as_u32 = saddr.ip4.as_u32; + + if (proto == SNAT_PROTOCOL_TCP) + checksum = &tcp->checksum; + else + checksum = &udp->checksum; + csum = ip_csum_sub_even (*checksum, dport); + csum = ip_csum_add_even (csum, udp->dst_port); + *checksum = ip_csum_fold (csum); } return 0; } +static int +nat64_in2out_tcp_udp_hairpinning (vlib_main_t * vm, vlib_buffer_t * b, + ip6_header_t * ip6) +{ + nat64_main_t *nm = &nat64_main; + nat64_db_bib_entry_t *bibe; + nat64_db_st_entry_t *ste; + ip46_address_t saddr, daddr; + u32 sw_if_index, fib_index; + udp_header_t *udp = ip6_next_header (ip6); + tcp_header_t *tcp = ip6_next_header (ip6); + snat_protocol_t proto = ip_proto_to_snat_proto (ip6->protocol); + u16 sport = udp->src_port; + u16 dport = udp->dst_port; + u16 *checksum; + ip_csum_t csum; + + sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX]; + fib_index = + fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index); + + saddr.as_u64[0] = ip6->src_address.as_u64[0]; + saddr.as_u64[1] = ip6->src_address.as_u64[1]; + daddr.as_u64[0] = ip6->dst_address.as_u64[0]; + daddr.as_u64[1] = ip6->dst_address.as_u64[1]; + + if (proto == SNAT_PROTOCOL_UDP) + checksum = &udp->checksum; + else + checksum = &tcp->checksum; + + csum = ip_csum_sub_even (*checksum, ip6->src_address.as_u64[0]); + csum = ip_csum_sub_even (csum, ip6->src_address.as_u64[1]); + csum = ip_csum_sub_even (csum, ip6->dst_address.as_u64[0]); + csum = ip_csum_sub_even (csum, ip6->dst_address.as_u64[1]); + csum = ip_csum_sub_even (csum, sport); + csum = ip_csum_sub_even (csum, dport); + + ste = + nat64_db_st_entry_find (&nm->db, &saddr, &daddr, sport, dport, proto, + fib_index, 1); + + if (ste) + { + bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index); + if (!bibe) + return -1; + } + else + { + bibe = + nat64_db_bib_entry_find (&nm->db, &saddr, sport, proto, fib_index, 1); + + if (!bibe) + { + u16 out_port; + ip4_address_t out_addr; + if (nat64_alloc_out_addr_and_port + (fib_index, proto, &out_addr, &out_port)) + return -1; + + bibe = + nat64_db_bib_entry_create (&nm->db, &ip6->src_address, &out_addr, + sport, clib_host_to_net_u16 (out_port), + fib_index, proto, 0); + if (!bibe) + return -1; + } + + ste = + nat64_db_st_entry_create (&nm->db, bibe, &ip6->dst_address, + &daddr.ip4, dport); + if (!ste) + return -1; + } + + nat64_session_reset_timeout (ste, vm); + + sport = udp->src_port = bibe->out_port; + memcpy (&ip6->src_address, well_known_prefix, sizeof (ip6_address_t)); + saddr.ip6.as_u32[3] = ip6->src_address.as_u32[3] = bibe->out_addr.as_u32; + + saddr.ip6.as_u32[0] = 0; + saddr.ip6.as_u32[1] = 0; + saddr.ip6.as_u32[2] = 0; + daddr.ip6.as_u32[0] = 0; + daddr.ip6.as_u32[1] = 0; + daddr.ip6.as_u32[2] = 0; + + ste = + nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto, 0, + 0); + + if (ste) + { + bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index); + if (!bibe) + return -1; + } + else + { + bibe = nat64_db_bib_entry_find (&nm->db, &daddr, dport, proto, 0, 0); + + if (!bibe) + return -1; + + ste = + nat64_db_st_entry_create (&nm->db, bibe, &ip6->src_address, + &saddr.ip4, sport); + } + + ip6->dst_address.as_u64[0] = bibe->in_addr.as_u64[0]; + ip6->dst_address.as_u64[1] = bibe->in_addr.as_u64[1]; + udp->dst_port = bibe->in_port; + + 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]); + csum = ip_csum_add_even (csum, udp->src_port); + csum = ip_csum_add_even (csum, udp->dst_port); + *checksum = ip_csum_fold (csum); + + return 0; +} + +static int +nat64_in2out_icmp_hairpinning (vlib_main_t * vm, vlib_buffer_t * b, + ip6_header_t * ip6) +{ + nat64_main_t *nm = &nat64_main; + nat64_db_bib_entry_t *bibe; + nat64_db_st_entry_t *ste; + icmp46_header_t *icmp = ip6_next_header (ip6); + ip6_header_t *inner_ip6; + ip46_address_t saddr, daddr; + u32 sw_if_index, fib_index; + snat_protocol_t proto; + udp_header_t *udp; + tcp_header_t *tcp; + u16 *checksum, sport, dport; + ip_csum_t csum; + + if (icmp->type == ICMP6_echo_request || icmp->type == ICMP6_echo_reply) + return -1; + + inner_ip6 = (ip6_header_t *) u8_ptr_add (icmp, 8); + + proto = ip_proto_to_snat_proto (inner_ip6->protocol); + + if (proto == SNAT_PROTOCOL_ICMP) + return -1; + + sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX]; + fib_index = + fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP6, sw_if_index); + + saddr.as_u64[0] = inner_ip6->src_address.as_u64[0]; + saddr.as_u64[1] = inner_ip6->src_address.as_u64[1]; + daddr.as_u64[0] = inner_ip6->dst_address.as_u64[0]; + daddr.as_u64[1] = inner_ip6->dst_address.as_u64[1]; + + udp = ip6_next_header (inner_ip6); + tcp = ip6_next_header (inner_ip6); + + sport = udp->src_port; + dport = udp->dst_port; + + if (proto == SNAT_PROTOCOL_UDP) + checksum = &udp->checksum; + else + checksum = &tcp->checksum; + + csum = ip_csum_sub_even (*checksum, inner_ip6->src_address.as_u64[0]); + csum = ip_csum_sub_even (csum, inner_ip6->src_address.as_u64[1]); + csum = ip_csum_sub_even (csum, inner_ip6->dst_address.as_u64[0]); + csum = ip_csum_sub_even (csum, inner_ip6->dst_address.as_u64[1]); + csum = ip_csum_sub_even (csum, sport); + csum = ip_csum_sub_even (csum, dport); + + ste = + nat64_db_st_entry_find (&nm->db, &daddr, &saddr, dport, sport, proto, + fib_index, 1); + if (!ste) + return -1; + + clib_warning (""); + bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index); + if (!bibe) + return -1; + + dport = udp->dst_port = bibe->out_port; + memcpy (&inner_ip6->dst_address, well_known_prefix, sizeof (ip6_address_t)); + daddr.ip6.as_u32[3] = inner_ip6->dst_address.as_u32[3] = + bibe->out_addr.as_u32; + + saddr.ip6.as_u32[0] = 0; + saddr.ip6.as_u32[1] = 0; + saddr.ip6.as_u32[2] = 0; + daddr.ip6.as_u32[0] = 0; + daddr.ip6.as_u32[1] = 0; + daddr.ip6.as_u32[2] = 0; + + ste = + nat64_db_st_entry_find (&nm->db, &saddr, &daddr, sport, dport, proto, 0, + 0); + if (!ste) + return -1; + + bibe = nat64_db_bib_entry_by_index (&nm->db, proto, ste->bibe_index); + if (!bibe) + return -1; + + inner_ip6->src_address.as_u64[0] = bibe->in_addr.as_u64[0]; + inner_ip6->src_address.as_u64[1] = bibe->in_addr.as_u64[1]; + udp->src_port = bibe->in_port; + + 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]); + csum = ip_csum_add_even (csum, udp->src_port); + csum = ip_csum_add_even (csum, udp->dst_port); + *checksum = ip_csum_fold (csum); + + if (!vec_len (nm->addr_pool)) + return -1; + + memcpy (&ip6->src_address, well_known_prefix, sizeof (ip6_address_t)); + ip6->src_address.as_u32[3] = nm->addr_pool[0].addr.as_u32; + ip6->dst_address.as_u64[0] = inner_ip6->src_address.as_u64[0]; + ip6->dst_address.as_u64[1] = inner_ip6->src_address.as_u64[1]; + + 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; +} + static uword nat64_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) @@ -343,7 +650,7 @@ nat64_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, ctx0.b = b0; ctx0.vm = vm; - next0 = NAT64_IN2OUT_NEXT_LOOKUP; + next0 = NAT64_IN2OUT_NEXT_IP4_LOOKUP; if (PREDICT_FALSE (ip6_parse @@ -366,6 +673,18 @@ nat64_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, if (proto0 == SNAT_PROTOCOL_ICMP) { + if (is_hairpinning (&ip60->dst_address)) + { + next0 = NAT64_IN2OUT_NEXT_IP6_LOOKUP; + if (nat64_in2out_icmp_hairpinning (vm, b0, ip60)) + { + next0 = NAT64_IN2OUT_NEXT_DROP; + b0->error = + node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION]; + } + goto trace0; + } + if (icmp6_to_icmp (b0, nat64_in2out_icmp_set_cb, &ctx0, nat64_in2out_inner_icmp_set_cb, &ctx0)) @@ -377,6 +696,18 @@ nat64_in2out_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node, } else { + if (is_hairpinning (&ip60->dst_address)) + { + next0 = NAT64_IN2OUT_NEXT_IP6_LOOKUP; + if (nat64_in2out_tcp_udp_hairpinning (vm, b0, ip60)) + { + next0 = NAT64_IN2OUT_NEXT_DROP; + b0->error = + node->errors[NAT64_IN2OUT_ERROR_NO_TRANSLATION]; + } + goto trace0; + } + if (ip6_to_ip4_tcp_udp (b0, nat64_in2out_tcp_udp_set_cb, &ctx0, 0)) { @@ -422,7 +753,8 @@ VLIB_REGISTER_NODE (nat64_in2out_node) = { /* edit / add dispositions here */ .next_nodes = { [NAT64_IN2OUT_NEXT_DROP] = "error-drop", - [NAT64_IN2OUT_NEXT_LOOKUP] = "ip4-lookup", + [NAT64_IN2OUT_NEXT_IP4_LOOKUP] = "ip4-lookup", + [NAT64_IN2OUT_NEXT_IP6_LOOKUP] = "ip6-lookup", }, }; /* *INDENT-ON* */ |