netfilter: xt_recent: Lift restrictions on max hitcount value

Support tracking of up to 65535 packets per table entry instead of just
255 to better facilitate longer term tracking or higher throughput
scenarios.

Note how this aligns sizes of struct recent_entry's 'nstamps' and
'index' fields when 'nstamps' was larger before. This is unnecessary as
the value of 'nstamps' grows along with that of 'index' after being
initialized to 1 (see recent_entry_update()). Its value will thus never
exceed that of 'index' and therefore does not need to provide space for
larger values.

Requested-by: Fabio <pedretti.fabio@gmail.com>
Link: https://bugzilla.netfilter.org/show_bug.cgi?id=1745
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index ef93e0d3bee04c7d984af9b9f45372265642b5ac..588a5e6ad8995e498bcba9a3e9df641d4fac9ec7 100644 (file)
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -59,9 +59,9 @@ MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* fil
 /* retained for backwards compatibility */
 static unsigned int ip_pkt_list_tot __read_mostly;
 module_param(ip_pkt_list_tot, uint, 0400);
-MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
+MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 65535)");
 
-#define XT_RECENT_MAX_NSTAMPS  256
+#define XT_RECENT_MAX_NSTAMPS  65536
 
 struct recent_entry {
        struct list_head        list;
@@ -69,7 +69,7 @@ struct recent_entry {
        union nf_inet_addr      addr;
        u_int16_t               family;
        u_int8_t                ttl;
-       u_int8_t                index;
+       u_int16_t               index;
        u_int16_t               nstamps;
        unsigned long           stamps[];
 };
@@ -80,7 +80,7 @@ struct recent_table {
        union nf_inet_addr      mask;
        unsigned int            refcnt;
        unsigned int            entries;
-       u8                      nstamps_max_mask;
+       u_int16_t               nstamps_max_mask;
        struct list_head        lru_list;
        struct list_head        iphash[];
 };