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Diffstat (limited to 'net/ipv6/netfilter/nft_fib_ipv6.c')
-rw-r--r--net/ipv6/netfilter/nft_fib_ipv6.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/nft_fib_ipv6.c b/net/ipv6/netfilter/nft_fib_ipv6.c
new file mode 100644
index 000000000000..c947aad8bcc6
--- /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 = nft_in(pkt);
+ else if (priv->flags & NFTA_FIB_F_OIF)
+ dev = nft_out(pkt);
+
+ nft_fib6_flowi_init(&fl6, priv, pkt, dev);
+
+ v6ops = nf_get_ipv6_ops();
+ if (dev && v6ops && v6ops->chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
+ ret = RTN_LOCAL;
+
+ route_err = afinfo->route(nft_net(pkt), (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 = &regs->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 = &regs->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 = nft_in(pkt);
+ else if (priv->flags & NFTA_FIB_F_OIF)
+ oif = nft_out(pkt);
+
+ lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif);
+
+ if (nft_hook(pkt) == 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(nft_net(pkt), &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 = ntohl(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");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.