target/linux/generic-2.6/patches-2.6.27/101-netfilter_layer7_pktmatch.patch

   1 diff --git a/include/linux/netfilter/xt_layer7.h b/include/linux/netfilter/xt_layer7.h
   2 index 147cd64..c38d3c4 100644
   3 --- a/include/linux/netfilter/xt_layer7.h
   4 +++ b/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 diff --git a/net/netfilter/xt_layer7.c b/net/netfilter/xt_layer7.c
  14 index a9b88d3..e0e962d 100644
  15 --- a/net/netfilter/xt_layer7.c
  16 +++ b/net/netfilter/xt_layer7.c
  17 @@ -314,33 +314,35 @@ static int match_no_append(struct nf_conn * conntrack,
  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                         /* the kernel version of tolower mungs 'upper ascii' */
  42 -                       master_conntrack->layer7.app_data[length+oldlength] =
  43 +                       target[length+offset] =
  44                                 isascii(app_data[i])?
  45                                         tolower(app_data[i]) : app_data[i];
  46                         length++;
  47                 }
  48         }
  49 +       target[length+offset] = '\0';
  50 +
  51 +       return length;
  52 +}
  53 +
  54 +/* add the new app data to the conntrack.  Return number of bytes added. */
  55 +static int add_data(struct nf_conn * master_conntrack,
  56 +                    char * app_data, int appdatalen)
  57 +{
  58 +       int length;
  59
  60 -       master_conntrack->layer7.app_data[length+oldlength] = '\0';
  61 -       master_conntrack->layer7.app_data_len = length + oldlength;
  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 @@ -428,7 +430,7 @@ match(const struct sk_buff *skbin,
  68         const struct xt_layer7_info * info = matchinfo;
  69         enum ip_conntrack_info master_ctinfo, ctinfo;
  70         struct nf_conn *master_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 @@ -456,8 +458,8 @@ match(const struct sk_buff *skbin,
  77                 master_conntrack = master_ct(master_conntrack);
  78
  79         /* if we've classified it or seen too many packets */
  80 -       if(total_acct_packets(master_conntrack) > num_packets ||
  81 -          master_conntrack->layer7.app_proto) {
  82 +       if(!info->pkt && (total_acct_packets(master_conntrack) > num_packets ||
  83 +          master_conntrack->layer7.app_proto)) {
  84
  85                 pattern_result = match_no_append(conntrack, master_conntrack,
  86                                                  ctinfo, master_ctinfo, info);
  87 @@ -490,6 +492,25 @@ match(const struct sk_buff *skbin,
  88         /* the return value gets checked later, when we're ready to use it */
  89         comppattern = compile_and_cache(info->pattern, info->protocol);
  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 +
 103 +               kfree(tmp_data);
 104 +               tmp_data = NULL;
 105 +               spin_unlock_bh(&l7_lock);
 106 +
 107 +               return (pattern_result ^ info->invert);
 108 +       }
 109 +
 110         /* On the first packet of a connection, allocate space for app data */
 111         if(total_acct_packets(master_conntrack) == 1 && !skb->cb[0] &&
 112            !master_conntrack->layer7.app_data){