target/linux/generic-2.6/patches-2.6.22/101-netfilter_layer7_pktmatch.patch

   1 Index: linux-2.6.22-rc6/include/linux/netfilter_ipv4/ipt_layer7.h
   2 ===================================================================
   3 --- linux-2.6.22-rc6.orig/include/linux/netfilter_ipv4/ipt_layer7.h     2007-07-02 03:23:28.597194750 +0200
   4 +++ linux-2.6.22-rc6/include/linux/netfilter_ipv4/ipt_layer7.h  2007-07-02 03:23:44.730203000 +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-2.6.22-rc6/net/ipv4/netfilter/ipt_layer7.c
  14 ===================================================================
  15 --- linux-2.6.22-rc6.orig/net/ipv4/netfilter/ipt_layer7.c       2007-07-02 03:23:28.609195500 +0200
  16 +++ linux-2.6.22-rc6/net/ipv4/netfilter/ipt_layer7.c    2007-07-02 03:23:54.234797000 +0200
  17 @@ -300,33 +300,34 @@
  18  }
  19
  20  /* add the new app data to the conntrack.  Return number of bytes added. */
  21 -static int add_data(struct nf_conn * master_conntrack,
  22 -                       char * app_data, int appdatalen)
  23 +static int add_datastr(char *target, int offset, char *app_data, int len)
  24  {
  25         int length = 0, i;
  26 -       int oldlength = master_conntrack->layer7.app_data_len;
  27 -
  28 -       // This is a fix for a race condition by Deti Fliegl. However, I'm not
  29 -       // clear on whether the race condition exists or whether this really
  30 -       // fixes it.  I might just be being dense... Anyway, if it's not really
  31 -       // a fix, all it does is waste a very small amount of time.
  32 -       if(!master_conntrack->layer7.app_data) return 0;
  33 +       if(!target) return 0;
  34
  35         /* Strip nulls. Make everything lower case (our regex lib doesn't
  36         do case insensitivity).  Add it to the end of the current data. */
  37 -       for(i = 0; i < maxdatalen-oldlength-1 &&
  38 -                  i < appdatalen; i++) {
  39 +       for(i = 0; i < maxdatalen-offset-1 && i < len; i++) {
  40                 if(app_data[i] != '\0') {
  41 -                       master_conntrack->layer7.app_data[length+oldlength] =
  42 +                       target[length+offset] =
  43                                 /* the kernel version of tolower mungs 'upper ascii' */
  44                                 isascii(app_data[i])? tolower(app_data[i]) : app_data[i];
  45                         length++;
  46                 }
  47         }
  48 +       target[length+offset] = '\0';
  49 +
  50 +       return length;
  51 +}
  52
  53 -       master_conntrack->layer7.app_data[length+oldlength] = '\0';
  54 -       master_conntrack->layer7.app_data_len = length + oldlength;
  55 +/* add the new app data to the conntrack.  Return number of bytes added. */
  56 +static int add_data(struct nf_conn * master_conntrack,
  57 +                       char * app_data, int appdatalen)
  58 +{
  59 +       int length;
  60
  61 +       length = add_datastr(master_conntrack->layer7.app_data, master_conntrack->layer7.app_data_len, app_data, appdatalen);
  62 +       master_conntrack->layer7.app_data_len += length;
  63         return length;
  64  }
  65
  66 @@ -343,7 +344,7 @@
  67         enum ip_conntrack_info master_ctinfo, ctinfo;
  68         struct nf_conn *master_conntrack;
  69         struct nf_conn *conntrack;
  70 -       unsigned char * app_data;
  71 +       unsigned char *app_data, *tmp_data;
  72         unsigned int pattern_result, appdatalen;
  73         regexp * comppattern;
  74
  75 @@ -365,8 +366,8 @@
  76                 master_conntrack = master_ct(master_conntrack);
  77
  78         /* if we've classified it or seen too many packets */
  79 -       if(TOTAL_PACKETS > num_packets ||
  80 -          master_conntrack->layer7.app_proto) {
  81 +       if(!info->pkt && (TOTAL_PACKETS > num_packets ||
  82 +               master_conntrack->layer7.app_proto)) {
  83
  84                 pattern_result = match_no_append(conntrack, master_conntrack, ctinfo, master_ctinfo, info);
  85
  86 @@ -396,6 +397,23 @@
  87         comppattern = compile_and_cache(info->pattern, info->protocol);
  88         spin_unlock_bh(&list_lock);
  89
  90 +       if (info->pkt) {
  91 +               tmp_data = kmalloc(maxdatalen, GFP_ATOMIC);
  92 +               if(!tmp_data){
  93 +                       if (net_ratelimit())
  94 +                               printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
  95 +                       return info->invert;
  96 +               }
  97 +
  98 +               tmp_data[0] = '\0';
  99 +               add_datastr(tmp_data, 0, app_data, appdatalen);
 100 +               pattern_result = ((comppattern && regexec(comppattern, tmp_data)) ? 1 : 0);
 101 +               kfree(tmp_data);
 102 +               tmp_data = NULL;
 103 +
 104 +               return (pattern_result ^ info->invert);
 105 +       }
 106 +
 107         /* On the first packet of a connection, allocate space for app data */
 108         write_lock(&ct_lock);
 109         if(TOTAL_PACKETS == 1 && !skb->cb[0] && !master_conntrack->layer7.app_data) {