target/linux/generic-2.4/patches/618-netfilter_multiport_backport.patch

   1 --- a/include/linux/netfilter_ipv4/ipt_multiport.h
   2 +++ b/include/linux/netfilter_ipv4/ipt_multiport.h
   3 @@ -11,11 +11,12 @@ enum ipt_multiport_flags
   4
   5  #define IPT_MULTI_PORTS        15
   6
   7 -/* Must fit inside union ipt_matchinfo: 16 bytes */
   8 -struct ipt_multiport
   9 +struct ipt_multiport_v1
  10  {
  11         u_int8_t flags;                         /* Type of comparison */
  12         u_int8_t count;                         /* Number of ports */
  13         u_int16_t ports[IPT_MULTI_PORTS];       /* Ports */
  14 +       u_int8_t pflags[IPT_MULTI_PORTS];       /* Port flags */
  15 +       u_int8_t invert;                        /* Invert flag */
  16  };
  17  #endif /*_IPT_MULTIPORT_H*/
  18 --- a/net/ipv4/netfilter/ipt_multiport.c
  19 +++ b/net/ipv4/netfilter/ipt_multiport.c
  20 @@ -1,5 +1,14 @@
  21  /* Kernel module to match one of a list of TCP/UDP ports: ports are in
  22     the same place so we can treat them as equal. */
  23 +
  24 +/* (C) 1999-2001 Paul `Rusty' Russell
  25 + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
  26 + *
  27 + * This program is free software; you can redistribute it and/or modify
  28 + * it under the terms of the GNU General Public License version 2 as
  29 + * published by the Free Software Foundation.
  30 + */
  31 +
  32  #include <linux/module.h>
  33  #include <linux/types.h>
  34  #include <linux/udp.h>
  35 @@ -8,97 +17,136 @@
  36  #include <linux/netfilter_ipv4/ipt_multiport.h>
  37  #include <linux/netfilter_ipv4/ip_tables.h>
  38
  39 +MODULE_LICENSE("GPL");
  40 +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  41 +MODULE_DESCRIPTION("iptables multiple port match module");
  42 +
  43  #if 0
  44  #define duprintf(format, args...) printk(format , ## args)
  45  #else
  46  #define duprintf(format, args...)
  47  #endif
  48
  49 +/* from linux 2.6 skbuff.h */
  50 +static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
  51 +                                      int len, void *buffer)
  52 +{
  53 +       int hlen = skb_headlen(skb);
  54 +
  55 +       if (hlen - offset >= len)
  56 +               return skb->data + offset;
  57 +
  58 +       if (skb_copy_bits(skb, offset, buffer, len) < 0)
  59 +               return NULL;
  60 +
  61 +       return buffer;
  62 +}
  63 +
  64 +
  65  /* Returns 1 if the port is matched by the test, 0 otherwise. */
  66  static inline int
  67 -ports_match(const u_int16_t *portlist, enum ipt_multiport_flags flags,
  68 -           u_int8_t count, u_int16_t src, u_int16_t dst)
  69 +ports_match_v1(const struct ipt_multiport_v1 *minfo,
  70 +              u_int16_t src, u_int16_t dst)
  71  {
  72         unsigned int i;
  73 -       for (i=0; i<count; i++) {
  74 -               if (flags != IPT_MULTIPORT_DESTINATION
  75 -                   && portlist[i] == src)
  76 -                       return 1;
  77 -
  78 -               if (flags != IPT_MULTIPORT_SOURCE
  79 -                   && portlist[i] == dst)
  80 -                       return 1;
  81 -       }
  82 +       u_int16_t s, e;
  83
  84 -       return 0;
  85 +       for (i=0; i < minfo->count; i++) {
  86 +               s = minfo->ports[i];
  87 +
  88 +               if (minfo->pflags[i]) {
  89 +                       /* range port matching */
  90 +                       e = minfo->ports[++i];
  91 +                       duprintf("src or dst matches with %d-%d?\n", s, e);
  92 +
  93 +                       if (minfo->flags == IPT_MULTIPORT_SOURCE
  94 +                           && src >= s && src <= e)
  95 +                               return 1 ^ minfo->invert;
  96 +                       if (minfo->flags == IPT_MULTIPORT_DESTINATION
  97 +                           && dst >= s && dst <= e)
  98 +                               return 1 ^ minfo->invert;
  99 +                       if (minfo->flags == IPT_MULTIPORT_EITHER
 100 +                           && ((dst >= s && dst <= e)
 101 +                               || (src >= s && src <= e)))
 102 +                               return 1 ^ minfo->invert;
 103 +               } else {
 104 +                       /* exact port matching */
 105 +                       duprintf("src or dst matches with %d?\n", s);
 106 +
 107 +                       if (minfo->flags == IPT_MULTIPORT_SOURCE
 108 +                           && src == s)
 109 +                               return 1 ^ minfo->invert;
 110 +                       if (minfo->flags == IPT_MULTIPORT_DESTINATION
 111 +                           && dst == s)
 112 +                               return 1 ^ minfo->invert;
 113 +                       if (minfo->flags == IPT_MULTIPORT_EITHER
 114 +                           && (src == s || dst == s))
 115 +                               return 1 ^ minfo->invert;
 116 +               }
 117 +       }
 118 +
 119 +       return minfo->invert;
 120  }
 121
 122  static int
 123 -match(const struct sk_buff *skb,
 124 -      const struct net_device *in,
 125 -      const struct net_device *out,
 126 -      const void *matchinfo,
 127 -      int offset,
 128 -      const void *hdr,
 129 -      u_int16_t datalen,
 130 -      int *hotdrop)
 131 +match_v1(const struct sk_buff *skb,
 132 +        const struct net_device *in,
 133 +        const struct net_device *out,
 134 +        const void *matchinfo,
 135 +        int offset,
 136 +        int *hotdrop)
 137  {
 138 -       const struct udphdr *udp = hdr;
 139 -       const struct ipt_multiport *multiinfo = matchinfo;
 140 +       u16 _ports[2], *pptr;
 141 +       const struct ipt_multiport_v1 *multiinfo = matchinfo;
 142 +
 143 +       if (offset)
 144 +               return 0;
 145
 146 -       /* Must be big enough to read ports. */
 147 -       if (offset == 0 && datalen < sizeof(struct udphdr)) {
 148 +       pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
 149 +                                 sizeof(_ports), _ports);
 150 +       if (pptr == NULL) {
 151                 /* We've been asked to examine this packet, and we
 152 -                  can't.  Hence, no choice but to drop. */
 153 -                       duprintf("ipt_multiport:"
 154 -                                " Dropping evil offset=0 tinygram.\n");
 155 -                       *hotdrop = 1;
 156 -                       return 0;
 157 +                * can't.  Hence, no choice but to drop.
 158 +                */
 159 +               duprintf("ipt_multiport:"
 160 +                        " Dropping evil offset=0 tinygram.\n");
 161 +               *hotdrop = 1;
 162 +               return 0;
 163         }
 164
 165 -       /* Must not be a fragment. */
 166 -       return !offset
 167 -               && ports_match(multiinfo->ports,
 168 -                              multiinfo->flags, multiinfo->count,
 169 -                              ntohs(udp->source), ntohs(udp->dest));
 170 +       return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
 171  }
 172
 173 -/* Called when user tries to insert an entry of this type. */
 174  static int
 175 -checkentry(const char *tablename,
 176 -          const struct ipt_ip *ip,
 177 -          void *matchinfo,
 178 -          unsigned int matchsize,
 179 -          unsigned int hook_mask)
 180 +checkentry_v1(const char *tablename,
 181 +             const struct ipt_ip *ip,
 182 +             void *matchinfo,
 183 +             unsigned int matchsize,
 184 +             unsigned int hook_mask)
 185  {
 186 -       const struct ipt_multiport *multiinfo = matchinfo;
 187 -
 188 -       if (matchsize != IPT_ALIGN(sizeof(struct ipt_multiport)))
 189 -               return 0;
 190 -
 191 -       /* Must specify proto == TCP/UDP, no unknown flags or bad count */
 192 -       return (ip->proto == IPPROTO_TCP || ip->proto == IPPROTO_UDP)
 193 -               && !(ip->invflags & IPT_INV_PROTO)
 194 -               && matchsize == IPT_ALIGN(sizeof(struct ipt_multiport))
 195 -               && (multiinfo->flags == IPT_MULTIPORT_SOURCE
 196 -                   || multiinfo->flags == IPT_MULTIPORT_DESTINATION
 197 -                   || multiinfo->flags == IPT_MULTIPORT_EITHER)
 198 -               && multiinfo->count <= IPT_MULTI_PORTS;
 199 +       return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport_v1)));
 200  }
 201
 202 -static struct ipt_match multiport_match
 203 -= { { NULL, NULL }, "multiport", &match, &checkentry, NULL, THIS_MODULE };
 204 +static struct ipt_match multiport_match_v1 = {
 205 +       .name           = "multiport",
 206 +       .match          = &match_v1,
 207 +       .checkentry     = &checkentry_v1,
 208 +       .me             = THIS_MODULE,
 209 +};
 210
 211  static int __init init(void)
 212  {
 213 -       return ipt_register_match(&multiport_match);
 214 +       int err;
 215 +
 216 +       err = ipt_register_match(&multiport_match_v1);
 217 +
 218 +       return err;
 219  }
 220
 221  static void __exit fini(void)
 222  {
 223 -       ipt_unregister_match(&multiport_match);
 224 +       ipt_unregister_match(&multiport_match_v1);
 225  }
 226
 227  module_init(init);
 228  module_exit(fini);
 229 -MODULE_LICENSE("GPL");