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

   1 diff -urN linux.old/include/linux/netfilter_ipv4/ipt_multiport.h linux.dev/include/linux/netfilter_ipv4/ipt_multiport.h
   2 --- linux.old/include/linux/netfilter_ipv4/ipt_multiport.h      2000-12-11 22:31:30.000000000 +0100
   3 +++ linux.dev/include/linux/netfilter_ipv4/ipt_multiport.h      2006-02-04 05:23:54.318518250 +0100
   4 @@ -11,11 +11,12 @@
   5
   6  #define IPT_MULTI_PORTS        15
   7
   8 -/* Must fit inside union ipt_matchinfo: 16 bytes */
   9 -struct ipt_multiport
  10 +struct ipt_multiport_v1
  11  {
  12         u_int8_t flags;                         /* Type of comparison */
  13         u_int8_t count;                         /* Number of ports */
  14         u_int16_t ports[IPT_MULTI_PORTS];       /* Ports */
  15 +       u_int8_t pflags[IPT_MULTI_PORTS];       /* Port flags */
  16 +       u_int8_t invert;                        /* Invert flag */
  17  };
  18  #endif /*_IPT_MULTIPORT_H*/
  19 diff -urN linux.old/net/ipv4/netfilter/ipt_multiport.c linux.dev/net/ipv4/netfilter/ipt_multiport.c
  20 --- linux.old/net/ipv4/netfilter/ipt_multiport.c        2003-06-13 16:51:39.000000000 +0200
  21 +++ linux.dev/net/ipv4/netfilter/ipt_multiport.c        2006-02-04 05:34:27.362081000 +0100
  22 @@ -1,5 +1,14 @@
  23  /* Kernel module to match one of a list of TCP/UDP ports: ports are in
  24     the same place so we can treat them as equal. */
  25 +
  26 +/* (C) 1999-2001 Paul `Rusty' Russell
  27 + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
  28 + *
  29 + * This program is free software; you can redistribute it and/or modify
  30 + * it under the terms of the GNU General Public License version 2 as
  31 + * published by the Free Software Foundation.
  32 + */
  33 +
  34  #include <linux/module.h>
  35  #include <linux/types.h>
  36  #include <linux/udp.h>
  37 @@ -8,97 +17,136 @@
  38  #include <linux/netfilter_ipv4/ipt_multiport.h>
  39  #include <linux/netfilter_ipv4/ip_tables.h>
  40
  41 +MODULE_LICENSE("GPL");
  42 +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
  43 +MODULE_DESCRIPTION("iptables multiple port match module");
  44 +
  45  #if 0
  46  #define duprintf(format, args...) printk(format , ## args)
  47  #else
  48  #define duprintf(format, args...)
  49  #endif
  50
  51 +/* from linux 2.6 skbuff.h */
  52 +static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
  53 +                                      int len, void *buffer)
  54 +{
  55 +       int hlen = skb_headlen(skb);
  56 +
  57 +       if (hlen - offset >= len)
  58 +               return skb->data + offset;
  59 +
  60 +       if (skb_copy_bits(skb, offset, buffer, len) < 0)
  61 +               return NULL;
  62 +
  63 +       return buffer;
  64 +}
  65 +
  66 +
  67  /* Returns 1 if the port is matched by the test, 0 otherwise. */
  68  static inline int
  69 -ports_match(const u_int16_t *portlist, enum ipt_multiport_flags flags,
  70 -           u_int8_t count, u_int16_t src, u_int16_t dst)
  71 +ports_match_v1(const struct ipt_multiport_v1 *minfo,
  72 +              u_int16_t src, u_int16_t dst)
  73  {
  74         unsigned int i;
  75 -       for (i=0; i<count; i++) {
  76 -               if (flags != IPT_MULTIPORT_DESTINATION
  77 -                   && portlist[i] == src)
  78 -                       return 1;
  79 -
  80 -               if (flags != IPT_MULTIPORT_SOURCE
  81 -                   && portlist[i] == dst)
  82 -                       return 1;
  83 -       }
  84 +       u_int16_t s, e;
  85
  86 -       return 0;
  87 +       for (i=0; i < minfo->count; i++) {
  88 +               s = minfo->ports[i];
  89 +
  90 +               if (minfo->pflags[i]) {
  91 +                       /* range port matching */
  92 +                       e = minfo->ports[++i];
  93 +                       duprintf("src or dst matches with %d-%d?\n", s, e);
  94 +
  95 +                       if (minfo->flags == IPT_MULTIPORT_SOURCE
  96 +                           && src >= s && src <= e)
  97 +                               return 1 ^ minfo->invert;
  98 +                       if (minfo->flags == IPT_MULTIPORT_DESTINATION
  99 +                           && dst >= s && dst <= e)
 100 +                               return 1 ^ minfo->invert;
 101 +                       if (minfo->flags == IPT_MULTIPORT_EITHER
 102 +                           && ((dst >= s && dst <= e)
 103 +                               || (src >= s && src <= e)))
 104 +                               return 1 ^ minfo->invert;
 105 +               } else {
 106 +                       /* exact port matching */
 107 +                       duprintf("src or dst matches with %d?\n", s);
 108 +
 109 +                       if (minfo->flags == IPT_MULTIPORT_SOURCE
 110 +                           && src == s)
 111 +                               return 1 ^ minfo->invert;
 112 +                       if (minfo->flags == IPT_MULTIPORT_DESTINATION
 113 +                           && dst == s)
 114 +                               return 1 ^ minfo->invert;
 115 +                       if (minfo->flags == IPT_MULTIPORT_EITHER
 116 +                           && (src == s || dst == s))
 117 +                               return 1 ^ minfo->invert;
 118 +               }
 119 +       }
 120 +
 121 +       return minfo->invert;
 122  }
 123
 124  static int
 125 -match(const struct sk_buff *skb,
 126 -      const struct net_device *in,
 127 -      const struct net_device *out,
 128 -      const void *matchinfo,
 129 -      int offset,
 130 -      const void *hdr,
 131 -      u_int16_t datalen,
 132 -      int *hotdrop)
 133 +match_v1(const struct sk_buff *skb,
 134 +        const struct net_device *in,
 135 +        const struct net_device *out,
 136 +        const void *matchinfo,
 137 +        int offset,
 138 +        int *hotdrop)
 139  {
 140 -       const struct udphdr *udp = hdr;
 141 -       const struct ipt_multiport *multiinfo = matchinfo;
 142 +       u16 _ports[2], *pptr;
 143 +       const struct ipt_multiport_v1 *multiinfo = matchinfo;
 144 +
 145 +       if (offset)
 146 +               return 0;
 147
 148 -       /* Must be big enough to read ports. */
 149 -       if (offset == 0 && datalen < sizeof(struct udphdr)) {
 150 +       pptr = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
 151 +                                 sizeof(_ports), _ports);
 152 +       if (pptr == NULL) {
 153                 /* We've been asked to examine this packet, and we
 154 -                  can't.  Hence, no choice but to drop. */
 155 -                       duprintf("ipt_multiport:"
 156 -                                " Dropping evil offset=0 tinygram.\n");
 157 -                       *hotdrop = 1;
 158 -                       return 0;
 159 +                * can't.  Hence, no choice but to drop.
 160 +                */
 161 +               duprintf("ipt_multiport:"
 162 +                        " Dropping evil offset=0 tinygram.\n");
 163 +               *hotdrop = 1;
 164 +               return 0;
 165         }
 166
 167 -       /* Must not be a fragment. */
 168 -       return !offset
 169 -               && ports_match(multiinfo->ports,
 170 -                              multiinfo->flags, multiinfo->count,
 171 -                              ntohs(udp->source), ntohs(udp->dest));
 172 +       return ports_match_v1(multiinfo, ntohs(pptr[0]), ntohs(pptr[1]));
 173  }
 174
 175 -/* Called when user tries to insert an entry of this type. */
 176  static int
 177 -checkentry(const char *tablename,
 178 -          const struct ipt_ip *ip,
 179 -          void *matchinfo,
 180 -          unsigned int matchsize,
 181 -          unsigned int hook_mask)
 182 +checkentry_v1(const char *tablename,
 183 +             const struct ipt_ip *ip,
 184 +             void *matchinfo,
 185 +             unsigned int matchsize,
 186 +             unsigned int hook_mask)
 187  {
 188 -       const struct ipt_multiport *multiinfo = matchinfo;
 189 -
 190 -       if (matchsize != IPT_ALIGN(sizeof(struct ipt_multiport)))
 191 -               return 0;
 192 -
 193 -       /* Must specify proto == TCP/UDP, no unknown flags or bad count */
 194 -       return (ip->proto == IPPROTO_TCP || ip->proto == IPPROTO_UDP)
 195 -               && !(ip->invflags & IPT_INV_PROTO)
 196 -               && matchsize == IPT_ALIGN(sizeof(struct ipt_multiport))
 197 -               && (multiinfo->flags == IPT_MULTIPORT_SOURCE
 198 -                   || multiinfo->flags == IPT_MULTIPORT_DESTINATION
 199 -                   || multiinfo->flags == IPT_MULTIPORT_EITHER)
 200 -               && multiinfo->count <= IPT_MULTI_PORTS;
 201 +       return (matchsize == IPT_ALIGN(sizeof(struct ipt_multiport_v1)));
 202  }
 203
 204 -static struct ipt_match multiport_match
 205 -= { { NULL, NULL }, "multiport", &match, &checkentry, NULL, THIS_MODULE };
 206 +static struct ipt_match multiport_match_v1 = {
 207 +       .name           = "multiport",
 208 +       .match          = &match_v1,
 209 +       .checkentry     = &checkentry_v1,
 210 +       .me             = THIS_MODULE,
 211 +};
 212
 213  static int __init init(void)
 214  {
 215 -       return ipt_register_match(&multiport_match);
 216 +       int err;
 217 +
 218 +       err = ipt_register_match(&multiport_match_v1);
 219 +
 220 +       return err;
 221  }
 222
 223  static void __exit fini(void)
 224  {
 225 -       ipt_unregister_match(&multiport_match);
 226 +       ipt_unregister_match(&multiport_match_v1);
 227  }
 228
 229  module_init(init);
 230  module_exit(fini);
 231 -MODULE_LICENSE("GPL");