target/linux/generic-2.6/patches/101-netfilter_layer7_pktmatch.patch

   1 Index: linux-2.6.21.5/include/linux/netfilter_ipv4/ipt_layer7.h
   2 ===================================================================
   3 --- linux-2.6.21.5.orig/include/linux/netfilter_ipv4/ipt_layer7.h       2007-07-02 00:43:58.271086750 +0200
   4 +++ linux-2.6.21.5/include/linux/netfilter_ipv4/ipt_layer7.h    2007-07-02 01:36:08.914739750 +0200
   5 @@ -21,6 +21,7 @@
   6      char protocol[MAX_PROTOCOL_LEN];
   7      char invert:1;
   8      char pattern[MAX_PATTERN_LEN];
   9 +    char pkt;
  10  };
  11
  12  #endif /* _IPT_LAYER7_H */
  13 Index: linux-2.6.21.5/net/ipv4/netfilter/ipt_layer7.c
  14 ===================================================================
  15 --- linux-2.6.21.5.orig/net/ipv4/netfilter/ipt_layer7.c 2007-07-02 01:27:54.195821750 +0200
  16 +++ linux-2.6.21.5/net/ipv4/netfilter/ipt_layer7.c      2007-07-02 01:37:01.990056750 +0200
  17 @@ -299,33 +299,34 @@
  18         }
  19  }
  20
  21 -/* add the new app data to the conntrack.  Return number of bytes added. */
  22 -static int add_data(struct ip_conntrack * master_conntrack,
  23 -                       char * app_data, int appdatalen)
  24 +static int add_datastr(char *target, int offset, char *app_data, int len)
  25  {
  26         int length = 0, i;
  27 -       int oldlength = master_conntrack->layer7.app_data_len;
  28 -
  29 -       // This is a fix for a race condition by Deti Fliegl. However, I'm not
  30 -       // clear on whether the race condition exists or whether this really
  31 -       // fixes it.  I might just be being dense... Anyway, if it's not really
  32 -       // a fix, all it does is waste a very small amount of time.
  33 -       if(!master_conntrack->layer7.app_data) return 0;
  34 +       if(!target) return 0;
  35
  36         /* Strip nulls. Make everything lower case (our regex lib doesn't
  37         do case insensitivity).  Add it to the end of the current data. */
  38 -       for(i = 0; i < maxdatalen-oldlength-1 &&
  39 -                  i < appdatalen; i++) {
  40 +       for(i = 0; i < maxdatalen-offset-1 && i < len; i++) {
  41                 if(app_data[i] != '\0') {
  42 -                       master_conntrack->layer7.app_data[length+oldlength] =
  43 +                       target[length+offset] =
  44                                 /* the kernel version of tolower mungs 'upper ascii' */
  45                                 isascii(app_data[i])? tolower(app_data[i]) : app_data[i];
  46                         length++;
  47                 }
  48         }
  49 +       target[length+offset] = '\0';
  50
  51 -       master_conntrack->layer7.app_data[length+oldlength] = '\0';
  52 -       master_conntrack->layer7.app_data_len = length + oldlength;
  53 +       return length;
  54 +}
  55 +
  56 +/* add the new app data to the conntrack.  Return number of bytes added. */
  57 +static int add_data(struct ip_conntrack * master_conntrack,
  58 +                       char * app_data, int appdatalen)
  59 +{
  60 +       int length;
  61 +
  62 +       length = add_datastr(master_conntrack->layer7.app_data, master_conntrack->layer7.app_data_len, app_data, appdatalen);
  63 +       master_conntrack->layer7.app_data_len += length;
  64
  65         return length;
  66  }
  67 @@ -343,7 +344,7 @@
  68         enum ip_conntrack_info master_ctinfo, ctinfo;
  69         struct nf_conn *master_conntrack;
  70         struct ip_conntrack *conntrack;
  71 -       unsigned char * app_data;
  72 +       unsigned char *app_data, *tmp_data;
  73         unsigned int pattern_result, appdatalen;
  74         regexp * comppattern;
  75
  76 @@ -365,8 +366,8 @@
  77                 master_conntrack = master_ct(master_conntrack);
  78
  79         /* if we've classified it or seen too many packets */
  80 -       if(TOTAL_PACKETS > num_packets ||
  81 -          master_conntrack->layer7.app_proto) {
  82 +       if(!info->pkt && (TOTAL_PACKETS > num_packets ||
  83 +               master_conntrack->layer7.app_proto)) {
  84
  85                 pattern_result = match_no_append(conntrack, master_conntrack, ctinfo, master_ctinfo, info);
  86
  87 @@ -396,6 +397,23 @@
  88         comppattern = compile_and_cache(info->pattern, info->protocol);
  89         spin_unlock_bh(&list_lock);
  90
  91 +       if (info->pkt) {
  92 +               tmp_data = kmalloc(maxdatalen, GFP_ATOMIC);
  93 +               if(!tmp_data){
  94 +                       if (net_ratelimit())
  95 +                               printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
  96 +                       return info->invert;
  97 +               }
  98 +
  99 +               tmp_data[0] = '\0';
 100 +               add_datastr(tmp_data, 0, app_data, appdatalen);
 101 +               pattern_result = ((comppattern && regexec(comppattern, tmp_data)) ? 1 : 0);
 102 +               kfree(tmp_data);
 103 +               tmp_data = NULL;
 104 +
 105 +               return (pattern_result ^ info->invert);
 106 +       }
 107 +
 108         /* On the first packet of a connection, allocate space for app data */
 109         write_lock(&ct_lock);
 110         if(TOTAL_PACKETS == 1 && !skb->cb[0] && !master_conntrack->layer7.app_data) {