net/ipv4/ipvs/ip_vs_proto_ah.c

   1 /*
   2  * ip_vs_proto_ah.c:    AH IPSec load balancing support for IPVS
   3  *
   4  * Version:     $Id: ip_vs_proto_ah.c,v 1.1 2003/07/04 15:04:37 wensong Exp $
   5  *
   6  * Authors:     Julian Anastasov <ja@ssi.bg>, February 2002
   7  *              Wensong Zhang <wensong@linuxvirtualserver.org>
   8  *
   9  *              This program is free software; you can redistribute it and/or
  10  *              modify it under the terms of the GNU General Public License
  11  *              version 2 as published by the Free Software Foundation;
  12  *
  13  */
  14
  15 #include <linux/in.h>
  16 #include <linux/ip.h>
  17 #include <linux/module.h>
  18 #include <linux/kernel.h>
  19 #include <linux/netfilter.h>
  20 #include <linux/netfilter_ipv4.h>
  21
  22 #include <net/ip_vs.h>
  23
  24
  25 /* TODO:
  26
  27 struct isakmp_hdr {
  28         __u8            icookie[8];
  29         __u8            rcookie[8];
  30         __u8            np;
  31         __u8            version;
  32         __u8            xchgtype;
  33         __u8            flags;
  34         __u32           msgid;
  35         __u32           length;
  36 };
  37
  38 */
  39
  40 #define PORT_ISAKMP     500
  41
  42
  43 static struct ip_vs_conn *
  44 ah_conn_in_get(const struct sk_buff *skb,
  45                struct ip_vs_protocol *pp,
  46                const struct iphdr *iph,
  47                unsigned int proto_off,
  48                int inverse)
  49 {
  50         struct ip_vs_conn *cp;
  51
  52         if (likely(!inverse)) {
  53                 cp = ip_vs_conn_in_get(IPPROTO_UDP,
  54                                        iph->saddr,
  55                                        htons(PORT_ISAKMP),
  56                                        iph->daddr,
  57                                        htons(PORT_ISAKMP));
  58         } else {
  59                 cp = ip_vs_conn_in_get(IPPROTO_UDP,
  60                                        iph->daddr,
  61                                        htons(PORT_ISAKMP),
  62                                        iph->saddr,
  63                                        htons(PORT_ISAKMP));
  64         }
  65
  66         if (!cp) {
  67                 /*
  68                  * We are not sure if the packet is from our
  69                  * service, so our conn_schedule hook should return NF_ACCEPT
  70                  */
  71                 IP_VS_DBG(12, "Unknown ISAKMP entry for outin packet "
  72                           "%s%s %u.%u.%u.%u->%u.%u.%u.%u\n",
  73                           inverse ? "ICMP+" : "",
  74                           pp->name,
  75                           NIPQUAD(iph->saddr),
  76                           NIPQUAD(iph->daddr));
  77         }
  78
  79         return cp;
  80 }
  81
  82
  83 static struct ip_vs_conn *
  84 ah_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
  85                 const struct iphdr *iph, unsigned int proto_off, int inverse)
  86 {
  87         struct ip_vs_conn *cp;
  88
  89         if (likely(!inverse)) {
  90                 cp = ip_vs_conn_out_get(IPPROTO_UDP,
  91                                         iph->saddr,
  92                                         htons(PORT_ISAKMP),
  93                                         iph->daddr,
  94                                         htons(PORT_ISAKMP));
  95         } else {
  96                 cp = ip_vs_conn_out_get(IPPROTO_UDP,
  97                                         iph->daddr,
  98                                         htons(PORT_ISAKMP),
  99                                         iph->saddr,
 100                                         htons(PORT_ISAKMP));
 101         }
 102
 103         if (!cp) {
 104                 IP_VS_DBG(12, "Unknown ISAKMP entry for inout packet "
 105                           "%s%s %u.%u.%u.%u->%u.%u.%u.%u\n",
 106                           inverse ? "ICMP+" : "",
 107                           pp->name,
 108                           NIPQUAD(iph->saddr),
 109                           NIPQUAD(iph->daddr));
 110         }
 111
 112         return cp;
 113 }
 114
 115
 116 static int
 117 ah_conn_schedule(struct sk_buff *skb,
 118                  struct ip_vs_protocol *pp,
 119                  int *verdict, struct ip_vs_conn **cpp)
 120 {
 121         /*
 122          * AH is only related traffic. Pass the packet to IP stack.
 123          */
 124         *verdict = NF_ACCEPT;
 125         return 0;
 126 }
 127
 128
 129 static void
 130 ah_debug_packet(struct ip_vs_protocol *pp, const struct sk_buff *skb,
 131                 int offset, const char *msg)
 132 {
 133         char buf[256];
 134         struct iphdr _iph, *ih;
 135
 136         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 137         if (ih == NULL)
 138                 sprintf(buf, "%s TRUNCATED", pp->name);
 139         else
 140                 sprintf(buf, "%s %u.%u.%u.%u->%u.%u.%u.%u",
 141                         pp->name, NIPQUAD(ih->saddr),
 142                         NIPQUAD(ih->daddr));
 143
 144         printk(KERN_DEBUG "IPVS: %s: %s\n", msg, buf);
 145 }
 146
 147
 148 static void ah_init(struct ip_vs_protocol *pp)
 149 {
 150         /* nothing to do now */
 151 }
 152
 153
 154 static void ah_exit(struct ip_vs_protocol *pp)
 155 {
 156         /* nothing to do now */
 157 }
 158
 159
 160 struct ip_vs_protocol ip_vs_protocol_ah = {
 161         .name =                 "AH",
 162         .protocol =             IPPROTO_AH,
 163         .num_states =           1,
 164         .dont_defrag =          1,
 165         .init =                 ah_init,
 166         .exit =                 ah_exit,
 167         .conn_schedule =        ah_conn_schedule,
 168         .conn_in_get =          ah_conn_in_get,
 169         .conn_out_get =         ah_conn_out_get,
 170         .snat_handler =         NULL,
 171         .dnat_handler =         NULL,
 172         .csum_check =           NULL,
 173         .state_transition =     NULL,
 174         .register_app =         NULL,
 175         .unregister_app =       NULL,
 176         .app_conn_bind =        NULL,
 177         .debug_packet =         ah_debug_packet,
 178         .timeout_change =       NULL,           /* ISAKMP */
 179         .set_state_timeout =    NULL,
 180 };