target/linux/generic-2.6/patches-2.6.25/101-netfilter_layer7_pktmatch.patch

   1 Index: linux-2.6.24/include/linux/netfilter/xt_layer7.h
   2 ===================================================================
   3 --- linux-2.6.24.orig/include/linux/netfilter/xt_layer7.h
   4 +++ linux-2.6.24/include/linux/netfilter/xt_layer7.h
   5 @@ -8,6 +8,7 @@ struct xt_layer7_info {
   6      char protocol[MAX_PROTOCOL_LEN];
   7      char pattern[MAX_PATTERN_LEN];
   8      u_int8_t invert;
   9 +    u_int8_t pkt;
  10  };
  11
  12  #endif /* _XT_LAYER7_H */
  13 Index: linux-2.6.24/net/netfilter/xt_layer7.c
  14 ===================================================================
  15 --- linux-2.6.24.orig/net/netfilter/xt_layer7.c
  16 +++ linux-2.6.24/net/netfilter/xt_layer7.c
  17 @@ -297,34 +297,36 @@ static int match_no_append(struct nf_con
  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 +
  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                         /* the kernel version of tolower mungs 'upper ascii' */
  43 -                       master_conntrack->layer7.app_data[length+oldlength] =
  44 +                       target[length+offset] =
  45                                 isascii(app_data[i])?
  46                                         tolower(app_data[i]) : app_data[i];
  47                         length++;
  48                 }
  49         }
  50 +       target[length+offset] = '\0';
  51 +
  52 +       return length;
  53 +}
  54
  55 -       master_conntrack->layer7.app_data[length+oldlength] = '\0';
  56 -       master_conntrack->layer7.app_data_len = length + oldlength;
  57 +/* add the new app data to the conntrack.  Return number of bytes added. */
  58 +static int add_data(struct nf_conn * master_conntrack,
  59 +                    char * app_data, int appdatalen)
  60 +{
  61 +       int length;
  62
  63 +       length = add_datastr(master_conntrack->layer7.app_data, master_conntrack->layer7.app_data_len, app_data, appdatalen);
  64 +       master_conntrack->layer7.app_data_len += length;
  65         return length;
  66  }
  67
  68 @@ -411,7 +413,7 @@ match(const struct sk_buff *skbin,
  69         const struct xt_layer7_info * info = matchinfo;
  70         enum ip_conntrack_info master_ctinfo, ctinfo;
  71         struct nf_conn *master_conntrack, *conntrack;
  72 -       unsigned char * app_data;
  73 +       unsigned char *app_data, *tmp_data;
  74         unsigned int pattern_result, appdatalen;
  75         regexp * comppattern;
  76
  77 @@ -439,8 +441,8 @@ match(const struct sk_buff *skbin,
  78                 master_conntrack = master_ct(master_conntrack);
  79
  80         /* if we've classified it or seen too many packets */
  81 -       if(TOTAL_PACKETS > num_packets ||
  82 -          master_conntrack->layer7.app_proto) {
  83 +       if(!info->pkt && (TOTAL_PACKETS > num_packets ||
  84 +          master_conntrack->layer7.app_proto)) {
  85
  86                 pattern_result = match_no_append(conntrack, master_conntrack,
  87                                                  ctinfo, master_ctinfo, info);
  88 @@ -473,6 +475,25 @@ match(const struct sk_buff *skbin,
  89         /* the return value gets checked later, when we're ready to use it */
  90         comppattern = compile_and_cache(info->pattern, info->protocol);
  91
  92 +       if (info->pkt) {
  93 +               tmp_data = kmalloc(maxdatalen, GFP_ATOMIC);
  94 +               if(!tmp_data){
  95 +                       if (net_ratelimit())
  96 +                               printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
  97 +                       return info->invert;
  98 +               }
  99 +
 100 +               tmp_data[0] = '\0';
 101 +               add_datastr(tmp_data, 0, app_data, appdatalen);
 102 +               pattern_result = ((comppattern && regexec(comppattern, tmp_data)) ? 1 : 0);
 103 +
 104 +               kfree(tmp_data);
 105 +               tmp_data = NULL;
 106 +               spin_unlock_bh(&l7_lock);
 107 +
 108 +               return (pattern_result ^ info->invert);
 109 +       }
 110 +
 111         /* On the first packet of a connection, allocate space for app data */
 112         if(TOTAL_PACKETS == 1 && !skb->cb[0] &&
 113            !master_conntrack->layer7.app_data){