f564650106
Netfilter assumes that if the socket is present in the skb, then it can be used because that reference is cleaned up while the skb is crossing netns. We want to change that to preserve the socket reference in a future patch, so this is a preparation updating netfilter to check if the socket netns matches before use it. Signed-off-by: Flavio Leitner <fbl@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
149 lines
3.4 KiB
C
149 lines
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#include <linux/module.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables_core.h>
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#include <net/netfilter/nf_socket.h>
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#include <net/inet_sock.h>
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#include <net/tcp.h>
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struct nft_socket {
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enum nft_socket_keys key:8;
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union {
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enum nft_registers dreg:8;
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};
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};
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static void nft_socket_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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const struct nft_socket *priv = nft_expr_priv(expr);
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struct sk_buff *skb = pkt->skb;
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struct sock *sk = skb->sk;
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u32 *dest = ®s->data[priv->dreg];
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if (sk && !net_eq(nft_net(pkt), sock_net(sk)))
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sk = NULL;
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if (!sk)
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switch(nft_pf(pkt)) {
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case NFPROTO_IPV4:
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sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt));
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break;
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#if IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
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case NFPROTO_IPV6:
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sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt));
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break;
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#endif
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default:
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WARN_ON_ONCE(1);
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regs->verdict.code = NFT_BREAK;
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return;
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}
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if (!sk) {
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nft_reg_store8(dest, 0);
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return;
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}
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/* So that subsequent socket matching not to require other lookups. */
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skb->sk = sk;
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switch(priv->key) {
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case NFT_SOCKET_TRANSPARENT:
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nft_reg_store8(dest, inet_sk_transparent(sk));
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break;
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default:
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WARN_ON(1);
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regs->verdict.code = NFT_BREAK;
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}
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}
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static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = {
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[NFTA_SOCKET_KEY] = { .type = NLA_U32 },
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[NFTA_SOCKET_DREG] = { .type = NLA_U32 },
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};
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static int nft_socket_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_socket *priv = nft_expr_priv(expr);
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unsigned int len;
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if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY])
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return -EINVAL;
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switch(ctx->family) {
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case NFPROTO_IPV4:
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#if IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
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case NFPROTO_IPV6:
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#endif
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case NFPROTO_INET:
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break;
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default:
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return -EOPNOTSUPP;
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}
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priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY]));
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switch(priv->key) {
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case NFT_SOCKET_TRANSPARENT:
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len = sizeof(u8);
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break;
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default:
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return -EOPNOTSUPP;
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}
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priv->dreg = nft_parse_register(tb[NFTA_SOCKET_DREG]);
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return nft_validate_register_store(ctx, priv->dreg, NULL,
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NFT_DATA_VALUE, len);
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}
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static int nft_socket_dump(struct sk_buff *skb,
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const struct nft_expr *expr)
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{
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const struct nft_socket *priv = nft_expr_priv(expr);
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if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key)))
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return -1;
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if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg))
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return -1;
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return 0;
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}
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static struct nft_expr_type nft_socket_type;
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static const struct nft_expr_ops nft_socket_ops = {
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.type = &nft_socket_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_socket)),
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.eval = nft_socket_eval,
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.init = nft_socket_init,
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.dump = nft_socket_dump,
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};
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static struct nft_expr_type nft_socket_type __read_mostly = {
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.name = "socket",
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.ops = &nft_socket_ops,
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.policy = nft_socket_policy,
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.maxattr = NFTA_SOCKET_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_socket_module_init(void)
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{
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return nft_register_expr(&nft_socket_type);
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}
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static void __exit nft_socket_module_exit(void)
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{
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nft_unregister_expr(&nft_socket_type);
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}
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module_init(nft_socket_module_init);
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module_exit(nft_socket_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Máté Eckl");
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MODULE_DESCRIPTION("nf_tables socket match module");
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MODULE_ALIAS_NFT_EXPR("socket");
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