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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /net/netfilter/xt_connbytes.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/netfilter/xt_connbytes.c')
-rw-r--r-- | net/netfilter/xt_connbytes.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/net/netfilter/xt_connbytes.c b/net/netfilter/xt_connbytes.c new file mode 100644 index 000000000..93cb018c3 --- /dev/null +++ b/net/netfilter/xt_connbytes.c @@ -0,0 +1,157 @@ +/* Kernel module to match connection tracking byte counter. + * GPL (C) 2002 Martin Devera (devik@cdi.cz). + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#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, struct xt_action_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_acct *acct; + const struct nf_conn_counter *counters; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + return false; + + acct = nf_conn_acct_find(ct); + if (!acct) + return false; + + counters = acct->counter; + switch (sinfo->what) { + case XT_CONNBYTES_PKTS: + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets); + break; + case XT_CONNBYTES_DIR_REPLY: + what = atomic64_read(&counters[IP_CT_DIR_REPLY].packets); + break; + case XT_CONNBYTES_DIR_BOTH: + what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets); + what += atomic64_read(&counters[IP_CT_DIR_REPLY].packets); + break; + } + break; + case XT_CONNBYTES_BYTES: + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes); + break; + case XT_CONNBYTES_DIR_REPLY: + what = atomic64_read(&counters[IP_CT_DIR_REPLY].bytes); + break; + case XT_CONNBYTES_DIR_BOTH: + what = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes); + what += atomic64_read(&counters[IP_CT_DIR_REPLY].bytes); + break; + } + break; + case XT_CONNBYTES_AVGPKT: + switch (sinfo->direction) { + case XT_CONNBYTES_DIR_ORIGINAL: + bytes = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes); + pkts = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets); + break; + case XT_CONNBYTES_DIR_REPLY: + bytes = atomic64_read(&counters[IP_CT_DIR_REPLY].bytes); + pkts = atomic64_read(&counters[IP_CT_DIR_REPLY].packets); + break; + case XT_CONNBYTES_DIR_BOTH: + bytes = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].bytes) + + atomic64_read(&counters[IP_CT_DIR_REPLY].bytes); + pkts = atomic64_read(&counters[IP_CT_DIR_ORIGINAL].packets) + + atomic64_read(&counters[IP_CT_DIR_REPLY].packets); + break; + } + if (pkts != 0) + what = div64_u64(bytes, pkts); + break; + } + + if (sinfo->count.to >= sinfo->count.from) + return what <= sinfo->count.to && what >= sinfo->count.from; + else /* inverted */ + return what < sinfo->count.to || what > sinfo->count.from; +} + +static int connbytes_mt_check(const struct xt_mtchk_param *par) +{ + const struct xt_connbytes_info *sinfo = par->matchinfo; + int ret; + + if (sinfo->what != XT_CONNBYTES_PKTS && + sinfo->what != XT_CONNBYTES_BYTES && + sinfo->what != XT_CONNBYTES_AVGPKT) + return -EINVAL; + + if (sinfo->direction != XT_CONNBYTES_DIR_ORIGINAL && + sinfo->direction != XT_CONNBYTES_DIR_REPLY && + sinfo->direction != XT_CONNBYTES_DIR_BOTH) + return -EINVAL; + + ret = nf_ct_netns_get(par->net, par->family); + if (ret < 0) + pr_info_ratelimited("cannot load conntrack support for proto=%u\n", + par->family); + + /* + * This filter cannot function correctly unless connection tracking + * accounting is enabled, so complain in the hope that someone notices. + */ + if (!nf_ct_acct_enabled(par->net)) { + pr_warn("Forcing CT accounting to be enabled\n"); + nf_ct_set_acct(par->net, true); + } + + return ret; +} + +static void connbytes_mt_destroy(const struct xt_mtdtor_param *par) +{ + nf_ct_netns_put(par->net, 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); |