lib/conntrack-icmp.c

   1 /*
   2  * Copyright (c) 2015, 2016 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18
  19 #include <errno.h>
  20 #include <sys/types.h>
  21 #include <netinet/in.h>
  22 #include <netinet/icmp6.h>
  23
  24 #include "conntrack-private.h"
  25 #include "dp-packet.h"
  26
  27 enum icmp_state {
  28     ICMPS_FIRST,
  29     ICMPS_REPLY,
  30 };
  31
  32 struct conn_icmp {
  33     struct conn up;
  34     enum icmp_state state;
  35 };
  36
  37 static const enum ct_timeout icmp_timeouts[] = {
  38     [ICMPS_FIRST] = CT_TM_ICMP_FIRST,
  39     [ICMPS_REPLY] = CT_TM_ICMP_REPLY,
  40 };
  41
  42 static struct conn_icmp *
  43 conn_icmp_cast(const struct conn *conn)
  44 {
  45     return CONTAINER_OF(conn, struct conn_icmp, up);
  46 }
  47
  48 static enum ct_update_res
  49 icmp_conn_update(struct conn *conn_, struct conntrack_bucket *ctb,
  50                  struct dp_packet *pkt OVS_UNUSED, bool reply, long long now)
  51 {
  52     struct conn_icmp *conn = conn_icmp_cast(conn_);
  53
  54     if (reply && conn->state != ICMPS_REPLY) {
  55         conn->state = ICMPS_REPLY;
  56     }
  57
  58     conn_update_expiration(ctb, &conn->up, icmp_timeouts[conn->state], now);
  59
  60     return CT_UPDATE_VALID;
  61 }
  62
  63 static bool
  64 icmp4_valid_new(struct dp_packet *pkt)
  65 {
  66     struct icmp_header *icmp = dp_packet_l4(pkt);
  67
  68     return icmp->icmp_type == ICMP4_ECHO_REQUEST
  69            || icmp->icmp_type == ICMP4_INFOREQUEST
  70            || icmp->icmp_type == ICMP4_TIMESTAMP;
  71 }
  72
  73 static bool
  74 icmp6_valid_new(struct dp_packet *pkt)
  75 {
  76     struct icmp6_header *icmp6 = dp_packet_l4(pkt);
  77
  78     return icmp6->icmp6_type == ICMP6_ECHO_REQUEST;
  79 }
  80
  81 static struct conn *
  82 icmp_new_conn(struct conntrack_bucket *ctb, struct dp_packet *pkt OVS_UNUSED,
  83                long long now)
  84 {
  85     struct conn_icmp *conn;
  86
  87     conn = xzalloc(sizeof *conn);
  88     conn->state = ICMPS_FIRST;
  89
  90     conn_init_expiration(ctb, &conn->up, icmp_timeouts[conn->state], now);
  91
  92     return &conn->up;
  93 }
  94
  95 struct ct_l4_proto ct_proto_icmp4 = {
  96     .new_conn = icmp_new_conn,
  97     .valid_new = icmp4_valid_new,
  98     .conn_update = icmp_conn_update,
  99 };
 100
 101 struct ct_l4_proto ct_proto_icmp6 = {
 102     .new_conn = icmp_new_conn,
 103     .valid_new = icmp6_valid_new,
 104     .conn_update = icmp_conn_update,
 105 };