diff options
Diffstat (limited to 'net/netfilter/xt_ipvs.c')
| -rw-r--r-- | net/netfilter/xt_ipvs.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/net/netfilter/xt_ipvs.c b/net/netfilter/xt_ipvs.c new file mode 100644 index 00000000000..7a4d66db95a --- /dev/null +++ b/net/netfilter/xt_ipvs.c @@ -0,0 +1,189 @@ +/* + * xt_ipvs - kernel module to match IPVS connection properties + * + * Author: Hannes Eder <heder@google.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/spinlock.h> +#include <linux/skbuff.h> +#ifdef CONFIG_IP_VS_IPV6 +#include <net/ipv6.h> +#endif +#include <linux/ip_vs.h> +#include <linux/types.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter/xt_ipvs.h> +#include <net/netfilter/nf_conntrack.h> + +#include <net/ip_vs.h> + +MODULE_AUTHOR("Hannes Eder <heder@google.com>"); +MODULE_DESCRIPTION("Xtables: match IPVS connection properties"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("ipt_ipvs"); +MODULE_ALIAS("ip6t_ipvs"); + +/* borrowed from xt_conntrack */ +static bool ipvs_mt_addrcmp(const union nf_inet_addr *kaddr, + const union nf_inet_addr *uaddr, + const union nf_inet_addr *umask, + unsigned int l3proto) +{ + if (l3proto == NFPROTO_IPV4) + return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0; +#ifdef CONFIG_IP_VS_IPV6 + else if (l3proto == NFPROTO_IPV6) + return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6, + &uaddr->in6) == 0; +#endif + else + return false; +} + +static bool +ipvs_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct xt_ipvs_mtinfo *data = par->matchinfo; + /* ipvs_mt_check ensures that family is only NFPROTO_IPV[46]. */ + const u_int8_t family = par->family; + struct ip_vs_iphdr iph; + struct ip_vs_protocol *pp; + struct ip_vs_conn *cp; + bool match = true; + + if (data->bitmask == XT_IPVS_IPVS_PROPERTY) { + match = skb->ipvs_property ^ + !!(data->invert & XT_IPVS_IPVS_PROPERTY); + goto out; + } + + /* other flags than XT_IPVS_IPVS_PROPERTY are set */ + if (!skb->ipvs_property) { + match = false; + goto out; + } + + ip_vs_fill_iphdr(family, skb_network_header(skb), &iph); + + if (data->bitmask & XT_IPVS_PROTO) + if ((iph.protocol == data->l4proto) ^ + !(data->invert & XT_IPVS_PROTO)) { + match = false; + goto out; + } + + pp = ip_vs_proto_get(iph.protocol); + if (unlikely(!pp)) { + match = false; + goto out; + } + + /* + * Check if the packet belongs to an existing entry + */ + cp = pp->conn_out_get(family, skb, pp, &iph, iph.len, 1 /* inverse */); + if (unlikely(cp == NULL)) { + match = false; + goto out; + } + + /* + * We found a connection, i.e. ct != 0, make sure to call + * __ip_vs_conn_put before returning. In our case jump to out_put_con. + */ + + if (data->bitmask & XT_IPVS_VPORT) + if ((cp->vport == data->vport) ^ + !(data->invert & XT_IPVS_VPORT)) { + match = false; + goto out_put_cp; + } + + if (data->bitmask & XT_IPVS_VPORTCTL) + if ((cp->control != NULL && + cp->control->vport == data->vportctl) ^ + !(data->invert & XT_IPVS_VPORTCTL)) { + match = false; + goto out_put_cp; + } + + if (data->bitmask & XT_IPVS_DIR) { + enum ip_conntrack_info ctinfo; + struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + + if (ct == NULL || nf_ct_is_untracked(ct)) { + match = false; + goto out_put_cp; + } + + if ((ctinfo >= IP_CT_IS_REPLY) ^ + !!(data->invert & XT_IPVS_DIR)) { + match = false; + goto out_put_cp; + } + } + + if (data->bitmask & XT_IPVS_METHOD) + if (((cp->flags & IP_VS_CONN_F_FWD_MASK) == data->fwd_method) ^ + !(data->invert & XT_IPVS_METHOD)) { + match = false; + goto out_put_cp; + } + + if (data->bitmask & XT_IPVS_VADDR) { + if (ipvs_mt_addrcmp(&cp->vaddr, &data->vaddr, + &data->vmask, family) ^ + !(data->invert & XT_IPVS_VADDR)) { + match = false; + goto out_put_cp; + } + } + +out_put_cp: + __ip_vs_conn_put(cp); +out: + pr_debug("match=%d\n", match); + return match; +} + +static int ipvs_mt_check(const struct xt_mtchk_param *par) +{ + if (par->family != NFPROTO_IPV4 +#ifdef CONFIG_IP_VS_IPV6 + && par->family != NFPROTO_IPV6 +#endif + ) { + pr_info("protocol family %u not supported\n", par->family); + return -EINVAL; + } + + return 0; +} + +static struct xt_match xt_ipvs_mt_reg __read_mostly = { + .name = "ipvs", + .revision = 0, + .family = NFPROTO_UNSPEC, + .match = ipvs_mt, + .checkentry = ipvs_mt_check, + .matchsize = XT_ALIGN(sizeof(struct xt_ipvs_mtinfo)), + .me = THIS_MODULE, +}; + +static int __init ipvs_mt_init(void) +{ + return xt_register_match(&xt_ipvs_mt_reg); +} + +static void __exit ipvs_mt_exit(void) +{ + xt_unregister_match(&xt_ipvs_mt_reg); +} + +module_init(ipvs_mt_init); +module_exit(ipvs_mt_exit); |