target/linux/generic/patches-2.6.37/601-netfilter_layer7_pktmatch.patch

   1 --- a/include/linux/netfilter/xt_layer7.h
   2 +++ b/include/linux/netfilter/xt_layer7.h
   3 @@ -8,6 +8,7 @@ struct xt_layer7_info {
   4      char protocol[MAX_PROTOCOL_LEN];
   5      char pattern[MAX_PATTERN_LEN];
   6      u_int8_t invert;
   7 +    u_int8_t pkt;
   8  };
   9
  10  #endif /* _XT_LAYER7_H */
  11 --- a/net/netfilter/xt_layer7.c
  12 +++ b/net/netfilter/xt_layer7.c
  13 @@ -314,33 +314,35 @@ static int match_no_append(struct nf_con
  14  }
  15
  16  /* add the new app data to the conntrack.  Return number of bytes added. */
  17 -static int add_data(struct nf_conn * master_conntrack,
  18 -                    char * app_data, int appdatalen)
  19 +static int add_datastr(char *target, int offset, char *app_data, int len)
  20  {
  21         int length = 0, i;
  22 -       int oldlength = master_conntrack->layer7.app_data_len;
  23 -
  24 -       /* This is a fix for a race condition by Deti Fliegl. However, I'm not
  25 -          clear on whether the race condition exists or whether this really
  26 -          fixes it.  I might just be being dense... Anyway, if it's not really
  27 -          a fix, all it does is waste a very small amount of time. */
  28 -       if(!master_conntrack->layer7.app_data) return 0;
  29 +       if (!target) return 0;
  30
  31         /* Strip nulls. Make everything lower case (our regex lib doesn't
  32         do case insensitivity).  Add it to the end of the current data. */
  33 -       for(i = 0; i < maxdatalen-oldlength-1 &&
  34 -                  i < appdatalen; i++) {
  35 +       for(i = 0; i < maxdatalen-offset-1 && i < len; i++) {
  36                 if(app_data[i] != '\0') {
  37                         /* the kernel version of tolower mungs 'upper ascii' */
  38 -                       master_conntrack->layer7.app_data[length+oldlength] =
  39 +                       target[length+offset] =
  40                                 isascii(app_data[i])?
  41                                         tolower(app_data[i]) : app_data[i];
  42                         length++;
  43                 }
  44         }
  45 +       target[length+offset] = '\0';
  46 +
  47 +       return length;
  48 +}
  49 +
  50 +/* add the new app data to the conntrack.  Return number of bytes added. */
  51 +static int add_data(struct nf_conn * master_conntrack,
  52 +                    char * app_data, int appdatalen)
  53 +{
  54 +       int length;
  55
  56 -       master_conntrack->layer7.app_data[length+oldlength] = '\0';
  57 -       master_conntrack->layer7.app_data_len = length + oldlength;
  58 +       length = add_datastr(master_conntrack->layer7.app_data, master_conntrack->layer7.app_data_len, app_data, appdatalen);
  59 +       master_conntrack->layer7.app_data_len += length;
  60
  61         return length;
  62  }
  63 @@ -438,7 +440,7 @@ match(const struct sk_buff *skbin,
  64
  65         enum ip_conntrack_info master_ctinfo, ctinfo;
  66         struct nf_conn *master_conntrack, *conntrack;
  67 -       unsigned char * app_data;
  68 +       unsigned char *app_data, *tmp_data;
  69         unsigned int pattern_result, appdatalen;
  70         regexp * comppattern;
  71
  72 @@ -466,8 +468,8 @@ match(const struct sk_buff *skbin,
  73                 master_conntrack = master_ct(master_conntrack);
  74
  75         /* if we've classified it or seen too many packets */
  76 -       if(total_acct_packets(master_conntrack) > num_packets ||
  77 -          master_conntrack->layer7.app_proto) {
  78 +       if(!info->pkt && (total_acct_packets(master_conntrack) > num_packets ||
  79 +          master_conntrack->layer7.app_proto)) {
  80
  81                 pattern_result = match_no_append(conntrack, master_conntrack,
  82                                                  ctinfo, master_ctinfo, info);
  83 @@ -500,6 +502,25 @@ match(const struct sk_buff *skbin,
  84         /* the return value gets checked later, when we're ready to use it */
  85         comppattern = compile_and_cache(info->pattern, info->protocol);
  86
  87 +       if (info->pkt) {
  88 +               tmp_data = kmalloc(maxdatalen, GFP_ATOMIC);
  89 +               if(!tmp_data){
  90 +                       if (net_ratelimit())
  91 +                               printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
  92 +                       return info->invert;
  93 +               }
  94 +
  95 +               tmp_data[0] = '\0';
  96 +               add_datastr(tmp_data, 0, app_data, appdatalen);
  97 +               pattern_result = ((comppattern && regexec(comppattern, tmp_data)) ? 1 : 0);
  98 +
  99 +               kfree(tmp_data);
 100 +               tmp_data = NULL;
 101 +               spin_unlock_bh(&l7_lock);
 102 +
 103 +               return (pattern_result ^ info->invert);
 104 +       }
 105 +
 106         /* On the first packet of a connection, allocate space for app data */
 107         if(total_acct_packets(master_conntrack) == 1 && !skb->cb[0] &&
 108            !master_conntrack->layer7.app_data){