| /* 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/netfilter/x_tables.h> |
| #include <linux/netfilter/xt_connbytes.h> |
| #include <net/netfilter/nf_conntrack.h> |
| |
| #include <asm/div64.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| MODULE_DESCRIPTION("iptables match for matching number of pkts/bytes per connection"); |
| MODULE_ALIAS("ipt_connbytes"); |
| MODULE_ALIAS("ip6t_connbytes"); |
| |
| static bool |
| connbytes_mt(const struct sk_buff *skb, const struct net_device *in, |
| const struct net_device *out, const struct xt_match *match, |
| const void *matchinfo, int offset, unsigned int protoff, |
| bool *hotdrop) |
| { |
| const struct xt_connbytes_info *sinfo = 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 ip_conntrack_counter *counters; |
| |
| ct = nf_ct_get(skb, &ctinfo); |
| if (!ct) |
| return false; |
| counters = ct->counters; |
| |
| 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_64(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 char *tablename, const void *ip, |
| const struct xt_match *match, void *matchinfo, |
| unsigned int hook_mask) |
| { |
| const struct xt_connbytes_info *sinfo = 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(match->family) < 0) { |
| printk(KERN_WARNING "can't load conntrack support for " |
| "proto=%d\n", match->family); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static void |
| connbytes_mt_destroy(const struct xt_match *match, void *matchinfo) |
| { |
| nf_ct_l3proto_module_put(match->family); |
| } |
| |
| static struct xt_match connbytes_mt_reg[] __read_mostly = { |
| { |
| .name = "connbytes", |
| .family = AF_INET, |
| .checkentry = connbytes_mt_check, |
| .match = connbytes_mt, |
| .destroy = connbytes_mt_destroy, |
| .matchsize = sizeof(struct xt_connbytes_info), |
| .me = THIS_MODULE |
| }, |
| { |
| .name = "connbytes", |
| .family = AF_INET6, |
| .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_matches(connbytes_mt_reg, |
| ARRAY_SIZE(connbytes_mt_reg)); |
| } |
| |
| static void __exit connbytes_mt_exit(void) |
| { |
| xt_unregister_matches(connbytes_mt_reg, ARRAY_SIZE(connbytes_mt_reg)); |
| } |
| |
| module_init(connbytes_mt_init); |
| module_exit(connbytes_mt_exit); |