release/src-rt-6.x/linux/linux-2.6/include/linux/netfilter_ipv4/ip_set_getport.h

   1 #ifndef _IP_SET_GETPORT_H
   2 #define _IP_SET_GETPORT_H
   3
   4 #ifdef __KERNEL__
   5
   6 #define INVALID_PORT    (MAX_RANGE + 1)
   7
   8 /* We must handle non-linear skbs */
   9 static inline ip_set_ip_t
  10 get_port(const struct sk_buff *skb, const u_int32_t *flags)
  11 {
  12         struct iphdr *iph = ip_hdr(skb);
  13         u_int16_t offset = ntohs(iph->frag_off) & IP_OFFSET;
  14         switch (iph->protocol) {
  15         case IPPROTO_TCP: {
  16                 struct tcphdr tcph;
  17
  18                 /* See comments at tcp_match in ip_tables.c */
  19                 if (offset)
  20                         return INVALID_PORT;
  21
  22                 if (skb_copy_bits(skb, ip_hdr(skb)->ihl*4, &tcph, sizeof(tcph)) < 0)
  23                         /* No choice either */
  24                         return INVALID_PORT;
  25
  26                 return ntohs(flags[0] & IPSET_SRC ?
  27                              tcph.source : tcph.dest);
  28             }
  29         case IPPROTO_UDP: {
  30                 struct udphdr udph;
  31
  32                 if (offset)
  33                         return INVALID_PORT;
  34
  35                 if (skb_copy_bits(skb, ip_hdr(skb)->ihl*4, &udph, sizeof(udph)) < 0)
  36                         /* No choice either */
  37                         return INVALID_PORT;
  38
  39                 return ntohs(flags[0] & IPSET_SRC ?
  40                              udph.source : udph.dest);
  41             }
  42         default:
  43                 return INVALID_PORT;
  44         }
  45 }
  46 #endif                          /* __KERNEL__ */
  47
  48 #endif /*_IP_SET_GETPORT_H*/