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authorMatus Fabian <matfabia@cisco.com>2017-06-15 02:28:50 -0700
committerOle Trøan <otroan@employees.org>2017-06-19 11:08:47 +0000
commit029f3d2c1c6b04a6cfef17242cb36b304025fe23 (patch)
tree5036e25543b5d43deeb15fde31135a3531d864ce /src/plugins/snat/nat64_in2out.c
parentacd4c63e3c6e70ea3f58527d9bace7c0e38df719 (diff)
NAT64: Hairpinning (VPP-699)
Change-Id: I83a6c277fa211ac2c2ca2d603650c992886af0a7 Signed-off-by: Matus Fabian <matfabia@cisco.com>
Diffstat (limited to 'src/plugins/snat/nat64_in2out.c')
-rw-r--r--src/plugins/snat/nat64_in2out.c338
1 files changed, 335 insertions, 3 deletions
diff --git a/src/plugins/snat/nat64_in2out.c b/src/plugins/snat/nat64_in2out.c
index eba6932681f..fd32bfc5be7 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* */