diff options
Diffstat (limited to 'net/netfilter/xt_connbytes.c')
| -rw-r--r-- | net/netfilter/xt_connbytes.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/net/netfilter/xt_connbytes.c b/net/netfilter/xt_connbytes.c new file mode 100644 index 0000000..955e659 --- /dev/null +++ b/net/netfilter/xt_connbytes.c @@ -0,0 +1,145 @@ +/* Kernel module to match connection tracking byte counter. + * GPL (C) 2002 Martin Devera (devik@cdi.cz). + */ +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/skbuff.h> +#include <linux/math64.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter/xt_connbytes.h> +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_acct.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_DESCRIPTION("Xtables: Number of packets/bytes per connection matching"); +MODULE_ALIAS("ipt_connbytes"); +MODULE_ALIAS("ip6t_connbytes"); + +static bool +connbytes_mt(const struct sk_buff *skb, const struct xt_match_param *par) +{ + const struct xt_connbytes_info *sinfo = par->matchinfo; + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + u_int64_t what = 0; /* initialize to make gcc happy */ + u_int64_t bytes = 0; + u_int64_t pkts = 0; + const struct nf_conn_counter *counters; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + return false; + + counters = nf_conn_acct_find(ct); + if (!counters) + return false; + + switch (sinfo->what) { + case XT_CONNBYTES_PKTS: + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + what = counters[IP_CT_DIR_ORIGINAL].packets; + break; + case XT_CONNBYTES_DIR_REPLY: + what = counters[IP_CT_DIR_REPLY].packets; + break; + case XT_CONNBYTES_DIR_BOTH: + what = counters[IP_CT_DIR_ORIGINAL].packets; + what += counters[IP_CT_DIR_REPLY].packets; + break; + } + break; + case XT_CONNBYTES_BYTES: + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + what = counters[IP_CT_DIR_ORIGINAL].bytes; + break; + case XT_CONNBYTES_DIR_REPLY: + what = counters[IP_CT_DIR_REPLY].bytes; + break; + case XT_CONNBYTES_DIR_BOTH: + what = counters[IP_CT_DIR_ORIGINAL].bytes; + what += counters[IP_CT_DIR_REPLY].bytes; + break; + } + break; + case XT_CONNBYTES_AVGPKT: + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + bytes = counters[IP_CT_DIR_ORIGINAL].bytes; + pkts = counters[IP_CT_DIR_ORIGINAL].packets; + break; + case XT_CONNBYTES_DIR_REPLY: + bytes = counters[IP_CT_DIR_REPLY].bytes; + pkts = counters[IP_CT_DIR_REPLY].packets; + break; + case XT_CONNBYTES_DIR_BOTH: + bytes = counters[IP_CT_DIR_ORIGINAL].bytes + + counters[IP_CT_DIR_REPLY].bytes; + pkts = counters[IP_CT_DIR_ORIGINAL].packets + + counters[IP_CT_DIR_REPLY].packets; + break; + } + if (pkts != 0) + what = div64_u64(bytes, pkts); + break; + } + + if (sinfo->count.to) + return what <= sinfo->count.to && what >= sinfo->count.from; + else + return what >= sinfo->count.from; +} + +static bool connbytes_mt_check(const struct xt_mtchk_param *par) +{ + const struct xt_connbytes_info *sinfo = par->matchinfo; + + if (sinfo->what != XT_CONNBYTES_PKTS && + sinfo->what != XT_CONNBYTES_BYTES && + sinfo->what != XT_CONNBYTES_AVGPKT) + return false; + + if (sinfo->direction != XT_CONNBYTES_DIR_ORIGINAL && + sinfo->direction != XT_CONNBYTES_DIR_REPLY && + sinfo->direction != XT_CONNBYTES_DIR_BOTH) + return false; + + if (nf_ct_l3proto_try_module_get(par->family) < 0) { + printk(KERN_WARNING "can't load conntrack support for " + "proto=%u\n", par->family); + return false; + } + + return true; +} + +static void connbytes_mt_destroy(const struct xt_mtdtor_param *par) +{ + nf_ct_l3proto_module_put(par->family); +} + +static struct xt_match connbytes_mt_reg __read_mostly = { + .name = "connbytes", + .revision = 0, + .family = NFPROTO_UNSPEC, + .checkentry = connbytes_mt_check, + .match = connbytes_mt, + .destroy = connbytes_mt_destroy, + .matchsize = sizeof(struct xt_connbytes_info), + .me = THIS_MODULE, +}; + +static int __init connbytes_mt_init(void) +{ + return xt_register_match(&connbytes_mt_reg); +} + +static void __exit connbytes_mt_exit(void) +{ + xt_unregister_match(&connbytes_mt_reg); +} + +module_init(connbytes_mt_init); +module_exit(connbytes_mt_exit); |
