diff options
| -rw-r--r-- | include/linux/netfilter_ipv4/ipt_connbytes.h | 25 | ||||
| -rw-r--r-- | net/ipv4/netfilter/Kconfig | 11 | ||||
| -rw-r--r-- | net/ipv4/netfilter/Makefile | 1 | ||||
| -rw-r--r-- | net/ipv4/netfilter/ipt_connbytes.c | 166 |
4 files changed, 202 insertions, 1 deletions
diff --git a/include/linux/netfilter_ipv4/ipt_connbytes.h b/include/linux/netfilter_ipv4/ipt_connbytes.h new file mode 100644 index 00000000000..abaa65afd4e --- /dev/null +++ b/include/linux/netfilter_ipv4/ipt_connbytes.h @@ -0,0 +1,25 @@ +#ifndef _IPT_CONNBYTES_H +#define _IPT_CONNBYTES_H + +enum ipt_connbytes_what { + IPT_CONNBYTES_WHAT_PKTS, + IPT_CONNBYTES_WHAT_BYTES, + IPT_CONNBYTES_WHAT_AVGPKT, +}; + +enum ipt_connbytes_direction { + IPT_CONNBYTES_DIR_ORIGINAL, + IPT_CONNBYTES_DIR_REPLY, + IPT_CONNBYTES_DIR_BOTH, +}; + +struct ipt_connbytes_info +{ + struct { + aligned_u64 from; /* count to be matched */ + aligned_u64 to; /* count to be matched */ + } count; + u_int8_t what; /* ipt_connbytes_what */ + u_int8_t direction; /* ipt_connbytes_direction */ +}; +#endif diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index 9f5e1d769b5..3f7e6e49cbd 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -386,6 +386,16 @@ config IP_NF_MATCH_CONNMARK <file:Documentation/modules.txt>. The module will be called ipt_connmark.o. If unsure, say `N'. +config IP_NF_MATCH_CONNBYTES + tristate 'Connection byte/packet counter match support' + depends on IP_NF_CT_ACCT && IP_NF_IPTABLES + help + This option adds a `connbytes' match, which allows you to match the + number of bytes and/or packets for each direction within a connection. + + If you want to compile it as a module, say M here and read + <file:Documentation/modules.txt>. If unsure, say `N'. + config IP_NF_MATCH_HASHLIMIT tristate 'hashlimit match support' depends on IP_NF_IPTABLES @@ -723,6 +733,5 @@ config IP_NF_CONNTRACK_NETLINK help This option enables support for a netlink-based userspace interface - endmenu diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 58aa7c616e1..7c8ae858aa4 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_IP_NF_MATCH_TTL) += ipt_ttl.o obj-$(CONFIG_IP_NF_MATCH_STATE) += ipt_state.o obj-$(CONFIG_IP_NF_MATCH_CONNMARK) += ipt_connmark.o obj-$(CONFIG_IP_NF_MATCH_CONNTRACK) += ipt_conntrack.o +obj-$(CONFIG_IP_NF_MATCH_CONNBYTES) += ipt_connbytes.o obj-$(CONFIG_IP_NF_MATCH_TCPMSS) += ipt_tcpmss.o obj-$(CONFIG_IP_NF_MATCH_REALM) += ipt_realm.o obj-$(CONFIG_IP_NF_MATCH_ADDRTYPE) += ipt_addrtype.o diff --git a/net/ipv4/netfilter/ipt_connbytes.c b/net/ipv4/netfilter/ipt_connbytes.c new file mode 100644 index 00000000000..0dfb52c0e80 --- /dev/null +++ b/net/ipv4/netfilter/ipt_connbytes.c @@ -0,0 +1,166 @@ +/* Kernel module to match connection tracking byte counter. + * GPL (C) 2002 Martin Devera (devik@cdi.cz). + * + * 2004-07-20 Harald Welte <laforge@netfilter.org> + * - reimplemented to use per-connection accounting counters + * - add functionality to match number of packets + * - add functionality to match average packet size + * - add support to match directions seperately + * + */ +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netfilter_ipv4/ip_conntrack.h> +#include <linux/netfilter_ipv4/ip_tables.h> +#include <linux/netfilter_ipv4/ipt_connbytes.h> + +#include <asm/div64.h> +#include <asm/bitops.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); +MODULE_DESCRIPTION("iptables match for matching number of pkts/bytes per connection"); + +/* 64bit divisor, dividend and result. dynamic precision */ +static u_int64_t div64_64(u_int64_t divisor, u_int64_t dividend) +{ + u_int64_t result = divisor; + + if (dividend > 0xffffffff) { + int first_bit = find_first_bit((unsigned long *) ÷nd, sizeof(dividend)); + /* calculate number of bits to shift. shift exactly enough + * bits to make dividend fit in 32bits. */ + int num_shift = (64 - 32 - first_bit); + /* first bit has to be < 32, since dividend was > 0xffffffff */ + result = result >> num_shift; + dividend = dividend >> num_shift; + } + + do_div(divisor, dividend); + + return divisor; +} + +static int +match(const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const void *matchinfo, + int offset, + int *hotdrop) +{ + const struct ipt_connbytes_info *sinfo = matchinfo; + enum ip_conntrack_info ctinfo; + struct ip_conntrack *ct; + u_int64_t what = 0; /* initialize to make gcc happy */ + + if (!(ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo))) + return 0; /* no match */ + + switch (sinfo->what) { + case IPT_CONNBYTES_WHAT_PKTS: + switch (sinfo->direction) { + case IPT_CONNBYTES_DIR_ORIGINAL: + what = ct->counters[IP_CT_DIR_ORIGINAL].packets; + break; + case IPT_CONNBYTES_DIR_REPLY: + what = ct->counters[IP_CT_DIR_REPLY].packets; + break; + case IPT_CONNBYTES_DIR_BOTH: + what = ct->counters[IP_CT_DIR_ORIGINAL].packets; + what += ct->counters[IP_CT_DIR_REPLY].packets; + break; + } + break; + case IPT_CONNBYTES_WHAT_BYTES: + switch (sinfo->direction) { + case IPT_CONNBYTES_DIR_ORIGINAL: + what = ct->counters[IP_CT_DIR_ORIGINAL].bytes; + break; + case IPT_CONNBYTES_DIR_REPLY: + what = ct->counters[IP_CT_DIR_REPLY].bytes; + break; + case IPT_CONNBYTES_DIR_BOTH: + what = ct->counters[IP_CT_DIR_ORIGINAL].bytes; + what += ct->counters[IP_CT_DIR_REPLY].bytes; + break; + } + break; + case IPT_CONNBYTES_WHAT_AVGPKT: + switch (sinfo->direction) { + case IPT_CONNBYTES_DIR_ORIGINAL: + what = div64_64(ct->counters[IP_CT_DIR_ORIGINAL].bytes, + ct->counters[IP_CT_DIR_ORIGINAL].packets); + break; + case IPT_CONNBYTES_DIR_REPLY: + what = div64_64(ct->counters[IP_CT_DIR_REPLY].bytes, + ct->counters[IP_CT_DIR_REPLY].packets); + break; + case IPT_CONNBYTES_DIR_BOTH: + { + u_int64_t bytes; + u_int64_t pkts; + bytes = ct->counters[IP_CT_DIR_ORIGINAL].bytes + + ct->counters[IP_CT_DIR_REPLY].bytes; + pkts = ct->counters[IP_CT_DIR_ORIGINAL].packets+ + ct->counters[IP_CT_DIR_REPLY].packets; + + /* FIXME_THEORETICAL: what to do if sum + * overflows ? */ + + what = div64_64(bytes, pkts); + } + break; + } + break; + } + + if (sinfo->count.to) + return (what <= sinfo->count.to && what >= sinfo->count.from); + else + return (what >= sinfo->count.from); +} + +static int check(const char *tablename, + const struct ipt_ip *ip, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + const struct ipt_connbytes_info *sinfo = matchinfo; + + if (matchsize != IPT_ALIGN(sizeof(struct ipt_connbytes_info))) + return 0; + + if (sinfo->what != IPT_CONNBYTES_WHAT_PKTS && + sinfo->what != IPT_CONNBYTES_WHAT_BYTES && + sinfo->what != IPT_CONNBYTES_WHAT_AVGPKT) + return 0; + + if (sinfo->direction != IPT_CONNBYTES_DIR_ORIGINAL && + sinfo->direction != IPT_CONNBYTES_DIR_REPLY && + sinfo->direction != IPT_CONNBYTES_DIR_BOTH) + return 0; + + return 1; +} + +static struct ipt_match state_match = { + .name = "connbytes", + .match = &match, + .checkentry = &check, + .me = THIS_MODULE +}; + +static int __init init(void) +{ + return ipt_register_match(&state_match); +} + +static void __exit fini(void) +{ + ipt_unregister_match(&state_match); +} + +module_init(init); +module_exit(fini); |