release/src-rt-6.x/linux/linux-2.6/net/bridge/netfilter/ebt_ip6.c

   1 /*
   2  *  ebt_ip6
   3  *
   4  *      Authors:
   5  *      Manohar Castelino <manohar.r.castelino@intel.com>
   6  *      Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
   7  *      Jan Engelhardt <jengelh@computergmbh.de>
   8  *
   9  * Summary:
  10  * This is just a modification of the IPv4 code written by
  11  * Bart De Schuymer <bdschuym@pandora.be>
  12  * with the changes required to support IPv6
  13  *
  14  *  Jan, 2008
  15  */
  16
  17 #include <linux/netfilter_bridge/ebtables.h>
  18 #include <linux/netfilter_bridge/ebt_ip6.h>
  19 #include <linux/ipv6.h>
  20 #include <net/ipv6.h>
  21 #include <linux/in.h>
  22 #include <linux/module.h>
  23 #include <net/dsfield.h>
  24
  25 union pkthdr {
  26         struct {
  27                 __be16 src;
  28                 __be16 dst;
  29         } tcpudphdr;
  30         struct {
  31                 u8 type;
  32                 u8 code;
  33         } icmphdr;
  34 };
  35
  36 static int ebt_filter_ip6(const struct sk_buff *skb,
  37    const struct net_device *in,
  38    const struct net_device *out, const void *data,
  39    unsigned int datalen)
  40 {
  41         const struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
  42         struct ipv6hdr *ih6;
  43         struct ipv6hdr _ip6h;
  44         const union pkthdr *pptr;
  45         union pkthdr _pkthdr;
  46         struct in6_addr tmp_addr;
  47         int i;
  48
  49         ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
  50         if (ih6 == NULL)
  51                 return EBT_NOMATCH;
  52         if (info->bitmask & EBT_IP6_TCLASS &&
  53            FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
  54                 return EBT_NOMATCH;
  55         for (i = 0; i < 4; i++)
  56                 tmp_addr.in6_u.u6_addr32[i] = ih6->saddr.in6_u.u6_addr32[i] &
  57                         info->smsk.in6_u.u6_addr32[i];
  58         if (info->bitmask & EBT_IP6_SOURCE &&
  59                 FWINV((ipv6_addr_cmp(&tmp_addr, &info->saddr) != 0),
  60                         EBT_IP6_SOURCE))
  61                 return EBT_NOMATCH;
  62         for (i = 0; i < 4; i++)
  63                 tmp_addr.in6_u.u6_addr32[i] = ih6->daddr.in6_u.u6_addr32[i] &
  64                         info->dmsk.in6_u.u6_addr32[i];
  65         if (info->bitmask & EBT_IP6_DEST &&
  66            FWINV((ipv6_addr_cmp(&tmp_addr, &info->daddr) != 0), EBT_IP6_DEST))
  67                 return EBT_NOMATCH;
  68         if (info->bitmask & EBT_IP6_PROTO) {
  69                 uint8_t nexthdr = ih6->nexthdr;
  70                 int offset_ph;
  71
  72                 offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr);
  73                 if (offset_ph == -1)
  74                         return EBT_NOMATCH;
  75                 if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
  76                         return EBT_NOMATCH;
  77                 if (!(info->bitmask & ( EBT_IP6_DPORT |
  78                                         EBT_IP6_SPORT | EBT_IP6_ICMP6)))
  79                         return EBT_MATCH;
  80
  81                 /* min icmpv6 headersize is 4, so sizeof(_pkthdr) is ok. */
  82                 pptr = skb_header_pointer(skb, offset_ph, sizeof(_pkthdr),
  83                                           &_pkthdr);
  84                 if (pptr == NULL)
  85                         return EBT_NOMATCH;
  86                 if (info->bitmask & EBT_IP6_DPORT) {
  87                         u16 dst = ntohs(pptr->tcpudphdr.dst);
  88                         if (FWINV(dst < info->dport[0] ||
  89                                   dst > info->dport[1], EBT_IP6_DPORT))
  90                                 return EBT_NOMATCH;
  91                 }
  92                 if (info->bitmask & EBT_IP6_SPORT) {
  93                         u16 src = ntohs(pptr->tcpudphdr.src);
  94                         if (FWINV(src < info->sport[0] ||
  95                                   src > info->sport[1], EBT_IP6_SPORT))
  96                         return EBT_NOMATCH;
  97                 }
  98                 if ((info->bitmask & EBT_IP6_ICMP6) &&
  99                      FWINV(pptr->icmphdr.type < info->icmpv6_type[0] ||
 100                            pptr->icmphdr.type > info->icmpv6_type[1] ||
 101                            pptr->icmphdr.code < info->icmpv6_code[0] ||
 102                            pptr->icmphdr.code > info->icmpv6_code[1],
 103                                                         EBT_IP6_ICMP6))
 104                         return EBT_NOMATCH;
 105         }
 106         return EBT_MATCH;
 107 }
 108
 109 static int ebt_ip6_check(const char *tablename, unsigned int hookmask,
 110    const struct ebt_entry *e, void *data, unsigned int datalen)
 111 {
 112         struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
 113
 114         if (datalen != EBT_ALIGN(sizeof(struct ebt_ip6_info)))
 115                 return -EINVAL;
 116         if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
 117                 return -EINVAL;
 118         if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
 119                 return -EINVAL;
 120         if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
 121                 if (info->invflags & EBT_IP6_PROTO)
 122                         return -EINVAL;
 123                 if (info->protocol != IPPROTO_TCP &&
 124                     info->protocol != IPPROTO_UDP &&
 125                     info->protocol != IPPROTO_UDPLITE &&
 126                     info->protocol != IPPROTO_SCTP &&
 127                     info->protocol != IPPROTO_DCCP)
 128                          return -EINVAL;
 129         }
 130         if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
 131                 return -EINVAL;
 132         if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
 133                 return -EINVAL;
 134         if (info->bitmask & EBT_IP6_ICMP6) {
 135                 if ((info->invflags & EBT_IP6_PROTO) ||
 136                      info->protocol != IPPROTO_ICMPV6)
 137                         return -EINVAL;
 138                 if (info->icmpv6_type[0] > info->icmpv6_type[1] ||
 139                     info->icmpv6_code[0] > info->icmpv6_code[1])
 140                         return -EINVAL;
 141         }
 142         return 0;
 143 }
 144
 145 static struct ebt_match filter_ip6 =
 146 {
 147         .name           = EBT_IP6_MATCH,
 148         .match          = ebt_filter_ip6,
 149         .check          = ebt_ip6_check,
 150         .me             = THIS_MODULE,
 151 };
 152
 153 static int __init ebt_ip6_init(void)
 154 {
 155         return ebt_register_match(&filter_ip6);
 156 }
 157
 158 static void __exit ebt_ip6_fini(void)
 159 {
 160         ebt_unregister_match(&filter_ip6);
 161 }
 162
 163 module_init(ebt_ip6_init);
 164 module_exit(ebt_ip6_fini);
 165 MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
 166 MODULE_LICENSE("GPL");