diff options
Diffstat (limited to 'net/ipv6')
-rw-r--r-- | net/ipv6/netfilter/Kconfig | 14 | ||||
-rw-r--r-- | net/ipv6/netfilter/Makefile | 3 | ||||
-rw-r--r-- | net/ipv6/netfilter/nf_socket_ipv6.c | 151 | ||||
-rw-r--r-- | net/ipv6/netfilter/nft_fib_ipv6.c | 275 |
4 files changed, 443 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index e10a04c9cdc7..6acb2eecd986 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -25,6 +25,12 @@ config NF_CONNTRACK_IPV6 To compile it as a module, choose M here. If unsure, say N. +config NF_SOCKET_IPV6 + tristate "IPv6 socket lookup support" + help + This option enables the IPv6 socket lookup infrastructure. This + is used by the ip6tables socket match. + if NF_TABLES config NF_TABLES_IPV6 @@ -54,6 +60,14 @@ config NFT_DUP_IPV6 help This module enables IPv6 packet duplication support for nf_tables. +config NFT_FIB_IPV6 + tristate "nf_tables fib / ipv6 route lookup support" + select NFT_FIB + help + This module enables IPv6 FIB lookups, e.g. for reverse path filtering. + It also allows query of the FIB for the route type, e.g. local, unicast, + multicast or blackhole. + endif # NF_TABLES_IPV6 endif # NF_TABLES diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index b4f7d0b4e2af..fe180c96040e 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -24,6 +24,8 @@ obj-$(CONFIG_NF_NAT_MASQUERADE_IPV6) += nf_nat_masquerade_ipv6.o nf_defrag_ipv6-y := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o obj-$(CONFIG_NF_DEFRAG_IPV6) += nf_defrag_ipv6.o +obj-$(CONFIG_NF_SOCKET_IPV6) += nf_socket_ipv6.o + # logging obj-$(CONFIG_NF_LOG_IPV6) += nf_log_ipv6.o @@ -40,6 +42,7 @@ obj-$(CONFIG_NFT_REJECT_IPV6) += nft_reject_ipv6.o obj-$(CONFIG_NFT_MASQ_IPV6) += nft_masq_ipv6.o obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redir_ipv6.o obj-$(CONFIG_NFT_DUP_IPV6) += nft_dup_ipv6.o +obj-$(CONFIG_NFT_FIB_IPV6) += nft_fib_ipv6.o # matches obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o diff --git a/net/ipv6/netfilter/nf_socket_ipv6.c b/net/ipv6/netfilter/nf_socket_ipv6.c new file mode 100644 index 000000000000..ebb2bf84232a --- /dev/null +++ b/net/ipv6/netfilter/nf_socket_ipv6.c @@ -0,0 +1,151 @@ +/* + * Copyright (C) 2007-2008 BalaBit IT Ltd. + * Author: Krisztian Kovacs + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/skbuff.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/icmp.h> +#include <net/sock.h> +#include <net/inet_sock.h> +#include <net/inet6_hashtables.h> +#include <net/netfilter/ipv6/nf_defrag_ipv6.h> +#include <net/netfilter/nf_socket.h> +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif + +static int +extract_icmp6_fields(const struct sk_buff *skb, + unsigned int outside_hdrlen, + int *protocol, + const struct in6_addr **raddr, + const struct in6_addr **laddr, + __be16 *rport, + __be16 *lport, + struct ipv6hdr *ipv6_var) +{ + const struct ipv6hdr *inside_iph; + struct icmp6hdr *icmph, _icmph; + __be16 *ports, _ports[2]; + u8 inside_nexthdr; + __be16 inside_fragoff; + int inside_hdrlen; + + icmph = skb_header_pointer(skb, outside_hdrlen, + sizeof(_icmph), &_icmph); + if (icmph == NULL) + return 1; + + if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK) + return 1; + + inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), + sizeof(*ipv6_var), ipv6_var); + if (inside_iph == NULL) + return 1; + inside_nexthdr = inside_iph->nexthdr; + + inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + + sizeof(*ipv6_var), + &inside_nexthdr, &inside_fragoff); + if (inside_hdrlen < 0) + return 1; /* hjm: Packet has no/incomplete transport layer headers. */ + + if (inside_nexthdr != IPPROTO_TCP && + inside_nexthdr != IPPROTO_UDP) + return 1; + + ports = skb_header_pointer(skb, inside_hdrlen, + sizeof(_ports), &_ports); + if (ports == NULL) + return 1; + + /* the inside IP packet is the one quoted from our side, thus + * its saddr is the local address */ + *protocol = inside_nexthdr; + *laddr = &inside_iph->saddr; + *lport = ports[0]; + *raddr = &inside_iph->daddr; + *rport = ports[1]; + + return 0; +} + +static struct sock * +nf_socket_get_sock_v6(struct net *net, struct sk_buff *skb, int doff, + const u8 protocol, + const struct in6_addr *saddr, const struct in6_addr *daddr, + const __be16 sport, const __be16 dport, + const struct net_device *in) +{ + switch (protocol) { + case IPPROTO_TCP: + return inet6_lookup(net, &tcp_hashinfo, skb, doff, + saddr, sport, daddr, dport, + in->ifindex); + case IPPROTO_UDP: + return udp6_lib_lookup(net, saddr, sport, daddr, dport, + in->ifindex); + } + + return NULL; +} + +struct sock *nf_sk_lookup_slow_v6(struct net *net, const struct sk_buff *skb, + const struct net_device *indev) +{ + __be16 uninitialized_var(dport), uninitialized_var(sport); + const struct in6_addr *daddr = NULL, *saddr = NULL; + struct ipv6hdr *iph = ipv6_hdr(skb); + struct sk_buff *data_skb = NULL; + int doff = 0; + int thoff = 0, tproto; + + tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL); + if (tproto < 0) { + pr_debug("unable to find transport header in IPv6 packet, dropping\n"); + return NULL; + } + + if (tproto == IPPROTO_UDP || tproto == IPPROTO_TCP) { + struct udphdr _hdr, *hp; + + hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr); + if (hp == NULL) + return NULL; + + saddr = &iph->saddr; + sport = hp->source; + daddr = &iph->daddr; + dport = hp->dest; + data_skb = (struct sk_buff *)skb; + doff = tproto == IPPROTO_TCP ? + thoff + __tcp_hdrlen((struct tcphdr *)hp) : + thoff + sizeof(*hp); + + } else if (tproto == IPPROTO_ICMPV6) { + struct ipv6hdr ipv6_var; + + if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr, + &sport, &dport, &ipv6_var)) + return NULL; + } else { + return NULL; + } + + return nf_socket_get_sock_v6(net, data_skb, doff, tproto, saddr, daddr, + sport, dport, indev); +} +EXPORT_SYMBOL_GPL(nf_sk_lookup_slow_v6); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler"); +MODULE_DESCRIPTION("Netfilter IPv6 socket lookup infrastructure"); diff --git a/net/ipv6/netfilter/nft_fib_ipv6.c b/net/ipv6/netfilter/nft_fib_ipv6.c new file mode 100644 index 000000000000..ff1f1b6b4a4a --- /dev/null +++ b/net/ipv6/netfilter/nft_fib_ipv6.c @@ -0,0 +1,275 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <linux/netfilter_ipv6.h> +#include <net/netfilter/nf_tables_core.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/nft_fib.h> + +#include <net/ip6_fib.h> +#include <net/ip6_route.h> + +static bool fib6_is_local(const struct sk_buff *skb) +{ + const struct rt6_info *rt = (const void *)skb_dst(skb); + + return rt && (rt->rt6i_flags & RTF_LOCAL); +} + +static int get_ifindex(const struct net_device *dev) +{ + return dev ? dev->ifindex : 0; +} + +static int nft_fib6_flowi_init(struct flowi6 *fl6, const struct nft_fib *priv, + const struct nft_pktinfo *pkt, + const struct net_device *dev) +{ + const struct ipv6hdr *iph = ipv6_hdr(pkt->skb); + int lookup_flags = 0; + + if (priv->flags & NFTA_FIB_F_DADDR) { + fl6->daddr = iph->daddr; + fl6->saddr = iph->saddr; + } else { + fl6->daddr = iph->saddr; + fl6->saddr = iph->daddr; + } + + if (ipv6_addr_type(&fl6->daddr) & IPV6_ADDR_LINKLOCAL) { + lookup_flags |= RT6_LOOKUP_F_IFACE; + fl6->flowi6_oif = get_ifindex(dev ? dev : pkt->skb->dev); + } + + if (ipv6_addr_type(&fl6->saddr) & IPV6_ADDR_UNICAST) + lookup_flags |= RT6_LOOKUP_F_HAS_SADDR; + + if (priv->flags & NFTA_FIB_F_MARK) + fl6->flowi6_mark = pkt->skb->mark; + + fl6->flowlabel = (*(__be32 *)iph) & IPV6_FLOWINFO_MASK; + + return lookup_flags; +} + +static u32 __nft_fib6_eval_type(const struct nft_fib *priv, + const struct nft_pktinfo *pkt) +{ + const struct net_device *dev = NULL; + const struct nf_ipv6_ops *v6ops; + const struct nf_afinfo *afinfo; + int route_err, addrtype; + struct rt6_info *rt; + struct flowi6 fl6 = { + .flowi6_iif = LOOPBACK_IFINDEX, + .flowi6_proto = pkt->tprot, + }; + u32 ret = 0; + + afinfo = nf_get_afinfo(NFPROTO_IPV6); + if (!afinfo) + return RTN_UNREACHABLE; + + if (priv->flags & NFTA_FIB_F_IIF) + dev = pkt->in; + else if (priv->flags & NFTA_FIB_F_OIF) + dev = pkt->out; + + nft_fib6_flowi_init(&fl6, priv, pkt, dev); + + v6ops = nf_get_ipv6_ops(); + if (dev && v6ops && v6ops->chk_addr(pkt->net, &fl6.daddr, dev, true)) + ret = RTN_LOCAL; + + route_err = afinfo->route(pkt->net, (struct dst_entry **)&rt, + flowi6_to_flowi(&fl6), false); + if (route_err) + goto err; + + if (rt->rt6i_flags & RTF_REJECT) { + route_err = rt->dst.error; + dst_release(&rt->dst); + goto err; + } + + if (ipv6_anycast_destination((struct dst_entry *)rt, &fl6.daddr)) + ret = RTN_ANYCAST; + else if (!dev && rt->rt6i_flags & RTF_LOCAL) + ret = RTN_LOCAL; + + dst_release(&rt->dst); + + if (ret) + return ret; + + addrtype = ipv6_addr_type(&fl6.daddr); + + if (addrtype & IPV6_ADDR_MULTICAST) + return RTN_MULTICAST; + if (addrtype & IPV6_ADDR_UNICAST) + return RTN_UNICAST; + + return RTN_UNSPEC; + err: + switch (route_err) { + case -EINVAL: + return RTN_BLACKHOLE; + case -EACCES: + return RTN_PROHIBIT; + case -EAGAIN: + return RTN_THROW; + default: + break; + } + + return RTN_UNREACHABLE; +} + +void nft_fib6_eval_type(const struct nft_expr *expr, struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_fib *priv = nft_expr_priv(expr); + u32 *dest = ®s->data[priv->dreg]; + + *dest = __nft_fib6_eval_type(priv, pkt); +} +EXPORT_SYMBOL_GPL(nft_fib6_eval_type); + +void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_fib *priv = nft_expr_priv(expr); + const struct net_device *oif = NULL; + u32 *dest = ®s->data[priv->dreg]; + struct flowi6 fl6 = { + .flowi6_iif = LOOPBACK_IFINDEX, + .flowi6_proto = pkt->tprot, + }; + struct rt6_info *rt; + int lookup_flags; + + if (priv->flags & NFTA_FIB_F_IIF) + oif = pkt->in; + else if (priv->flags & NFTA_FIB_F_OIF) + oif = pkt->out; + + lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif); + + if (pkt->hook == NF_INET_PRE_ROUTING && fib6_is_local(pkt->skb)) { + nft_fib_store_result(dest, priv->result, pkt, LOOPBACK_IFINDEX); + return; + } + + *dest = 0; + again: + rt = (void *)ip6_route_lookup(pkt->net, &fl6, lookup_flags); + if (rt->dst.error) + goto put_rt_err; + + /* Should not see RTF_LOCAL here */ + if (rt->rt6i_flags & (RTF_REJECT | RTF_ANYCAST | RTF_LOCAL)) + goto put_rt_err; + + if (oif && oif != rt->rt6i_idev->dev) { + /* multipath route? Try again with F_IFACE */ + if ((lookup_flags & RT6_LOOKUP_F_IFACE) == 0) { + lookup_flags |= RT6_LOOKUP_F_IFACE; + fl6.flowi6_oif = oif->ifindex; + ip6_rt_put(rt); + goto again; + } + } + + switch (priv->result) { + case NFT_FIB_RESULT_OIF: + *dest = rt->rt6i_idev->dev->ifindex; + break; + case NFT_FIB_RESULT_OIFNAME: + strncpy((char *)dest, rt->rt6i_idev->dev->name, IFNAMSIZ); + break; + default: + WARN_ON_ONCE(1); + break; + } + + put_rt_err: + ip6_rt_put(rt); +} +EXPORT_SYMBOL_GPL(nft_fib6_eval); + +static struct nft_expr_type nft_fib6_type; + +static const struct nft_expr_ops nft_fib6_type_ops = { + .type = &nft_fib6_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)), + .eval = nft_fib6_eval_type, + .init = nft_fib_init, + .dump = nft_fib_dump, + .validate = nft_fib_validate, +}; + +static const struct nft_expr_ops nft_fib6_ops = { + .type = &nft_fib6_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_fib)), + .eval = nft_fib6_eval, + .init = nft_fib_init, + .dump = nft_fib_dump, + .validate = nft_fib_validate, +}; + +static const struct nft_expr_ops * +nft_fib6_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + enum nft_fib_result result; + + if (!tb[NFTA_FIB_RESULT]) + return ERR_PTR(-EINVAL); + + result = htonl(nla_get_be32(tb[NFTA_FIB_RESULT])); + + switch (result) { + case NFT_FIB_RESULT_OIF: + return &nft_fib6_ops; + case NFT_FIB_RESULT_OIFNAME: + return &nft_fib6_ops; + case NFT_FIB_RESULT_ADDRTYPE: + return &nft_fib6_type_ops; + default: + return ERR_PTR(-EOPNOTSUPP); + } +} + +static struct nft_expr_type nft_fib6_type __read_mostly = { + .name = "fib", + .select_ops = &nft_fib6_select_ops, + .policy = nft_fib_policy, + .maxattr = NFTA_FIB_MAX, + .family = NFPROTO_IPV6, + .owner = THIS_MODULE, +}; + +static int __init nft_fib6_module_init(void) +{ + return nft_register_expr(&nft_fib6_type); +} + +static void __exit nft_fib6_module_exit(void) +{ + nft_unregister_expr(&nft_fib6_type); +} +module_init(nft_fib6_module_init); +module_exit(nft_fib6_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Florian Westphal <fw@strlen.de>"); +MODULE_ALIAS_NFT_AF_EXPR(10, "fib"); |