diff options
| -rw-r--r-- | src/plugins/acl/fa_node.c | 138 |
1 files changed, 113 insertions, 25 deletions
diff --git a/src/plugins/acl/fa_node.c b/src/plugins/acl/fa_node.c index 5fa45098559..fb23a354358 100644 --- a/src/plugins/acl/fa_node.c +++ b/src/plugins/acl/fa_node.c @@ -24,6 +24,7 @@ #include <vppinfra/bihash_template.h> #include <vppinfra/bihash_template.c> +#include <vnet/ip/icmp46_packet.h> #include "fa_node.h" #include "hash_lookup.h" @@ -39,6 +40,37 @@ typedef struct u8 action; } acl_fa_trace_t; +/* ICMPv4 invert type for stateful ACL */ +static const u8 icmp4_invmap[] = { + [ICMP4_echo_reply] = ICMP4_echo_request + 1, + [ICMP4_timestamp_reply] = ICMP4_timestamp_request + 1, + [ICMP4_information_reply] = ICMP4_information_request + 1, + [ICMP4_address_mask_reply] = ICMP4_address_mask_request + 1 +}; + +/* Supported ICMPv4 messages for session creation */ +static const u8 icmp4_valid_new[] = { + [ICMP4_echo_request] = 1, + [ICMP4_timestamp_request] = 1, + [ICMP4_information_request] = 1, + [ICMP4_address_mask_request] = 1 +}; + +/* ICMPv6 invert type for stateful ACL */ +static const u8 icmp6_invmap[] = { + [ICMP6_echo_reply - 128] = ICMP6_echo_request + 1, + [ICMP6_node_information_response - 128] = ICMP6_node_information_request + 1 +}; + +/* Supported ICMPv6 messages for session creation */ +static const u8 icmp6_valid_new[] = { + [ICMP6_echo_request - 128] = 1, + [ICMP6_node_information_request - 128] = 1 +}; + +/* IP4 and IP6 protocol numbers of ICMP */ +static u8 icmp_protos[] = { IP_PROTOCOL_ICMP, IP_PROTOCOL_ICMP6 }; + static u8 * format_fa_5tuple (u8 * s, va_list * args) { @@ -365,9 +397,6 @@ acl_fill_5tuple (acl_main_t * am, vlib_buffer_t * b0, int is_ip6, u16 ports[2]; u16 proto; - /* IP4 and IP6 protocol numbers of ICMP */ - static u8 icmp_protos[] = { IP_PROTOCOL_ICMP, IP_PROTOCOL_ICMP6 }; - if (is_l2_path) { l3_offset = ethernet_buffer_header_size(b0); @@ -529,22 +558,6 @@ acl_fill_5tuple (acl_main_t * am, vlib_buffer_t * b0, int is_ip6, } } - -/* Session keys match the packets received, and mirror the packets sent */ -static void -acl_make_5tuple_session_key (int is_input, fa_5tuple_t * p5tuple_pkt, - fa_5tuple_t * p5tuple_sess) -{ - int src_index = is_input ? 0 : 1; - int dst_index = is_input ? 1 : 0; - p5tuple_sess->addr[src_index] = p5tuple_pkt->addr[0]; - p5tuple_sess->addr[dst_index] = p5tuple_pkt->addr[1]; - p5tuple_sess->l4.as_u64 = p5tuple_pkt->l4.as_u64; - p5tuple_sess->l4.port[src_index] = p5tuple_pkt->l4.port[0]; - p5tuple_sess->l4.port[dst_index] = p5tuple_pkt->l4.port[1]; -} - - static int acl_fa_ifc_has_sessions (acl_main_t * am, int sw_if_index0) { @@ -565,6 +578,70 @@ acl_fa_ifc_has_out_acl (acl_main_t * am, int sw_if_index0) return it_has; } +/* Session keys match the packets received, and mirror the packets sent */ +static u32 +acl_make_5tuple_session_key (acl_main_t * am, int is_input, int is_ip6, + u32 sw_if_index, fa_5tuple_t * p5tuple_pkt, + fa_5tuple_t * p5tuple_sess) +{ + int src_index = is_input ? 0 : 1; + int dst_index = is_input ? 1 : 0; + u32 valid_new_sess = 1; + p5tuple_sess->addr[src_index] = p5tuple_pkt->addr[0]; + p5tuple_sess->addr[dst_index] = p5tuple_pkt->addr[1]; + p5tuple_sess->l4.as_u64 = p5tuple_pkt->l4.as_u64; + + if (PREDICT_TRUE(p5tuple_pkt->l4.proto != icmp_protos[is_ip6])) + { + p5tuple_sess->l4.port[src_index] = p5tuple_pkt->l4.port[0]; + p5tuple_sess->l4.port[dst_index] = p5tuple_pkt->l4.port[1]; + } + else + { + static const u8 * icmp_invmap[] = { icmp4_invmap, icmp6_invmap }; + static const u8 * icmp_valid_new[] = { icmp4_valid_new, icmp6_valid_new }; + static const u8 icmp_invmap_size[] = { sizeof(icmp4_invmap), + sizeof(icmp6_invmap) }; + static const u8 icmp_valid_new_size[] = { sizeof(icmp4_valid_new), + sizeof(icmp6_valid_new) }; + int type = is_ip6 ? p5tuple_pkt->l4.port[0]-128: p5tuple_pkt->l4.port[0]; + + p5tuple_sess->l4.port[0] = p5tuple_pkt->l4.port[0]; + p5tuple_sess->l4.port[1] = p5tuple_pkt->l4.port[1]; + + /* + * Invert ICMP type for valid icmp_invmap messages: + * 1) input node with outbound ACL interface + * 2) output node with inbound ACL interface + * + */ + if ((is_input && acl_fa_ifc_has_out_acl(am, sw_if_index)) || + (!is_input && acl_fa_ifc_has_in_acl(am, sw_if_index))) + { + if (type >= 0 && + type <= icmp_invmap_size[is_ip6] && + icmp_invmap[is_ip6][type]) + { + p5tuple_sess->l4.port[0] = icmp_invmap[is_ip6][type] - 1; + } + } + + /* + * ONLY ICMP messages defined in icmp4_valid_new/icmp6_valid_new table + * are allowed to create stateful ACL. + * The other messages will be forwarded without creating a reflexive ACL. + */ + if (type < 0 || + type > icmp_valid_new_size[is_ip6] || + !icmp_valid_new[is_ip6][type]) + { + valid_new_sess = 0; + } + } + + return valid_new_sess; +} + static int fa_session_get_timeout_type (acl_main_t * am, fa_session_t * sess) @@ -1016,6 +1093,7 @@ acl_fa_node_fn (vlib_main_t * vm, u32 match_acl_in_index = ~0; u32 match_rule_index = ~0; u8 error0 = 0; + u32 valid_new_sess; /* speculatively enqueue b0 to the current next frame */ bi0 = from[0]; @@ -1040,7 +1118,7 @@ acl_fa_node_fn (vlib_main_t * vm, acl_fill_5tuple (am, b0, is_ip6, is_input, is_l2_path, &fa_5tuple); fa_5tuple.l4.lsb_of_sw_if_index = sw_if_index0 & 0xffff; - acl_make_5tuple_session_key (is_input, &fa_5tuple, &kv_sess); + valid_new_sess = acl_make_5tuple_session_key (am, is_input, is_ip6, sw_if_index0, &fa_5tuple, &kv_sess); fa_5tuple.pkt.sw_if_index = sw_if_index0; fa_5tuple.pkt.is_ip6 = is_ip6; fa_5tuple.pkt.is_input = is_input; @@ -1124,11 +1202,21 @@ acl_fa_node_fn (vlib_main_t * vm, if (acl_fa_can_add_session (am, is_input, sw_if_index0)) { - fa_session_t *sess = acl_fa_add_session (am, is_input, sw_if_index0, now, - &kv_sess); - acl_fa_track_session (am, is_input, sw_if_index0, now, - sess, &fa_5tuple); - pkts_new_session += 1; + if (PREDICT_TRUE (valid_new_sess)) { + fa_session_t *sess = acl_fa_add_session (am, is_input, + sw_if_index0, + now, &kv_sess); + acl_fa_track_session (am, is_input, sw_if_index0, now, + sess, &fa_5tuple); + pkts_new_session += 1; + } else { + /* + * ICMP packets with non-icmp_valid_new type will be + * forwared without being dropped. + */ + action = 1; + pkts_acl_permit += 1; + } } else { |