From 9c3e1c39679144c250dda95098333ecb5f1f407a Mon Sep 17 00:00:00 2001 From: Hannes Eder Date: Fri, 23 Jul 2010 12:42:58 +0200 Subject: [PATCH] netfilter: xt_ipvs (netfilter matcher for IPVS) This implements the kernel-space side of the netfilter matcher xt_ipvs. [ minor fixes by Simon Horman ] Signed-off-by: Hannes Eder Signed-off-by: Simon Horman [ Patrick: added xt_ipvs.h to Kbuild ] Signed-off-by: Patrick McHardy --- include/linux/netfilter/Kbuild | 1 + include/linux/netfilter/xt_ipvs.h | 27 +++++ net/netfilter/Kconfig | 10 ++ net/netfilter/Makefile | 1 + net/netfilter/ipvs/ip_vs_proto.c | 1 + net/netfilter/xt_ipvs.c | 189 ++++++++++++++++++++++++++++++ 6 files changed, 229 insertions(+) create mode 100644 include/linux/netfilter/xt_ipvs.h create mode 100644 net/netfilter/xt_ipvs.c diff --git a/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild index b93b64dc9fae..0cb62c857187 100644 --- a/include/linux/netfilter/Kbuild +++ b/include/linux/netfilter/Kbuild @@ -31,6 +31,7 @@ header-y += xt_dscp.h header-y += xt_esp.h header-y += xt_hashlimit.h header-y += xt_iprange.h +header-y += xt_ipvs.h header-y += xt_helper.h header-y += xt_length.h header-y += xt_limit.h diff --git a/include/linux/netfilter/xt_ipvs.h b/include/linux/netfilter/xt_ipvs.h new file mode 100644 index 000000000000..1167aeb7a347 --- /dev/null +++ b/include/linux/netfilter/xt_ipvs.h @@ -0,0 +1,27 @@ +#ifndef _XT_IPVS_H +#define _XT_IPVS_H + +enum { + XT_IPVS_IPVS_PROPERTY = 1 << 0, /* all other options imply this one */ + XT_IPVS_PROTO = 1 << 1, + XT_IPVS_VADDR = 1 << 2, + XT_IPVS_VPORT = 1 << 3, + XT_IPVS_DIR = 1 << 4, + XT_IPVS_METHOD = 1 << 5, + XT_IPVS_VPORTCTL = 1 << 6, + XT_IPVS_MASK = (1 << 7) - 1, + XT_IPVS_ONCE_MASK = XT_IPVS_MASK & ~XT_IPVS_IPVS_PROPERTY +}; + +struct xt_ipvs_mtinfo { + union nf_inet_addr vaddr, vmask; + __be16 vport; + __u8 l4proto; + __u8 fwd_method; + __be16 vportctl; + + __u8 invert; + __u8 bitmask; +}; + +#endif /* _XT_IPVS_H */ diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 5fb8efa84df3..551b58419df9 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -742,6 +742,16 @@ config NETFILTER_XT_MATCH_IPRANGE If unsure, say M. +config NETFILTER_XT_MATCH_IPVS + tristate '"ipvs" match support' + depends on IP_VS + depends on NETFILTER_ADVANCED + depends on NF_CONNTRACK + help + This option allows you to match against IPVS properties of a packet. + + If unsure, say N. + config NETFILTER_XT_MATCH_LENGTH tristate '"length" match support' depends on NETFILTER_ADVANCED diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 36ef8e63be1e..4366c79a6683 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -77,6 +77,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_HASHLIMIT) += xt_hashlimit.o obj-$(CONFIG_NETFILTER_XT_MATCH_HELPER) += xt_helper.o obj-$(CONFIG_NETFILTER_XT_MATCH_HL) += xt_hl.o obj-$(CONFIG_NETFILTER_XT_MATCH_IPRANGE) += xt_iprange.o +obj-$(CONFIG_NETFILTER_XT_MATCH_IPVS) += xt_ipvs.o obj-$(CONFIG_NETFILTER_XT_MATCH_LENGTH) += xt_length.o obj-$(CONFIG_NETFILTER_XT_MATCH_LIMIT) += xt_limit.o obj-$(CONFIG_NETFILTER_XT_MATCH_MAC) += xt_mac.o diff --git a/net/netfilter/ipvs/ip_vs_proto.c b/net/netfilter/ipvs/ip_vs_proto.c index 2d3d5e4b35f8..027f654799fe 100644 --- a/net/netfilter/ipvs/ip_vs_proto.c +++ b/net/netfilter/ipvs/ip_vs_proto.c @@ -98,6 +98,7 @@ struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto) return NULL; } +EXPORT_SYMBOL(ip_vs_proto_get); /* diff --git a/net/netfilter/xt_ipvs.c b/net/netfilter/xt_ipvs.c new file mode 100644 index 000000000000..7a4d66db95ae --- /dev/null +++ b/net/netfilter/xt_ipvs.c @@ -0,0 +1,189 @@ +/* + * xt_ipvs - kernel module to match IPVS connection properties + * + * Author: Hannes Eder + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#ifdef CONFIG_IP_VS_IPV6 +#include +#endif +#include +#include +#include +#include +#include +#include + +#include + +MODULE_AUTHOR("Hannes Eder "); +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); -- 2.34.1