diff options
Diffstat (limited to 'net/netfilter/nft_socket.c')
| -rw-r--r-- | net/netfilter/nft_socket.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/net/netfilter/nft_socket.c b/net/netfilter/nft_socket.c new file mode 100644 index 000000000..f28324fd8 --- /dev/null +++ b/net/netfilter/nft_socket.c @@ -0,0 +1,291 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/module.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables_core.h> +#include <net/netfilter/nf_socket.h> +#include <net/inet_sock.h> +#include <net/tcp.h> + +struct nft_socket { + enum nft_socket_keys key:8; + u8 level; + u8 len; + union { + u8 dreg; + }; +}; + +static void nft_socket_wildcard(const struct nft_pktinfo *pkt, + struct nft_regs *regs, struct sock *sk, + u32 *dest) +{ + switch (nft_pf(pkt)) { + case NFPROTO_IPV4: + nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0); + break; +#if IS_ENABLED(CONFIG_NF_TABLES_IPV6) + case NFPROTO_IPV6: + nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr)); + break; +#endif + default: + regs->verdict.code = NFT_BREAK; + return; + } +} + +#ifdef CONFIG_SOCK_CGROUP_DATA +static noinline bool +nft_sock_get_eval_cgroupv2(u32 *dest, struct sock *sk, const struct nft_pktinfo *pkt, u32 level) +{ + struct cgroup *cgrp; + u64 cgid; + + if (!sk_fullsock(sk)) + return false; + + cgrp = cgroup_ancestor(sock_cgroup_ptr(&sk->sk_cgrp_data), level); + if (!cgrp) + return false; + + cgid = cgroup_id(cgrp); + memcpy(dest, &cgid, sizeof(u64)); + return true; +} +#endif + +static struct sock *nft_socket_do_lookup(const struct nft_pktinfo *pkt) +{ + const struct net_device *indev = nft_in(pkt); + const struct sk_buff *skb = pkt->skb; + struct sock *sk = NULL; + + if (!indev) + return NULL; + + switch (nft_pf(pkt)) { + case NFPROTO_IPV4: + sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, indev); + break; +#if IS_ENABLED(CONFIG_NF_TABLES_IPV6) + case NFPROTO_IPV6: + sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, indev); + break; +#endif + default: + WARN_ON_ONCE(1); + break; + } + + return sk; +} + +static void nft_socket_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_socket *priv = nft_expr_priv(expr); + struct sk_buff *skb = pkt->skb; + struct sock *sk = skb->sk; + u32 *dest = ®s->data[priv->dreg]; + + if (sk && !net_eq(nft_net(pkt), sock_net(sk))) + sk = NULL; + + if (!sk) + sk = nft_socket_do_lookup(pkt); + + if (!sk) { + regs->verdict.code = NFT_BREAK; + return; + } + + switch(priv->key) { + case NFT_SOCKET_TRANSPARENT: + nft_reg_store8(dest, inet_sk_transparent(sk)); + break; + case NFT_SOCKET_MARK: + if (sk_fullsock(sk)) { + *dest = READ_ONCE(sk->sk_mark); + } else { + regs->verdict.code = NFT_BREAK; + return; + } + break; + case NFT_SOCKET_WILDCARD: + if (!sk_fullsock(sk)) { + regs->verdict.code = NFT_BREAK; + return; + } + nft_socket_wildcard(pkt, regs, sk, dest); + break; +#ifdef CONFIG_SOCK_CGROUP_DATA + case NFT_SOCKET_CGROUPV2: + if (!nft_sock_get_eval_cgroupv2(dest, sk, pkt, priv->level)) { + regs->verdict.code = NFT_BREAK; + return; + } + break; +#endif + default: + WARN_ON(1); + regs->verdict.code = NFT_BREAK; + } + + if (sk != skb->sk) + sock_gen_put(sk); +} + +static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { + [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, + [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, + [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 }, +}; + +static int nft_socket_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_socket *priv = nft_expr_priv(expr); + unsigned int len; + + if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) + return -EINVAL; + + switch(ctx->family) { + case NFPROTO_IPV4: +#if IS_ENABLED(CONFIG_NF_TABLES_IPV6) + case NFPROTO_IPV6: +#endif + case NFPROTO_INET: + break; + default: + return -EOPNOTSUPP; + } + + priv->key = ntohl(nla_get_be32(tb[NFTA_SOCKET_KEY])); + switch(priv->key) { + case NFT_SOCKET_TRANSPARENT: + case NFT_SOCKET_WILDCARD: + len = sizeof(u8); + break; + case NFT_SOCKET_MARK: + len = sizeof(u32); + break; +#ifdef CONFIG_CGROUPS + case NFT_SOCKET_CGROUPV2: { + unsigned int level; + + if (!tb[NFTA_SOCKET_LEVEL]) + return -EINVAL; + + level = ntohl(nla_get_be32(tb[NFTA_SOCKET_LEVEL])); + if (level > 255) + return -EOPNOTSUPP; + + priv->level = level; + len = sizeof(u64); + break; + } +#endif + default: + return -EOPNOTSUPP; + } + + priv->len = len; + return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, + NULL, NFT_DATA_VALUE, len); +} + +static int nft_socket_dump(struct sk_buff *skb, + const struct nft_expr *expr) +{ + const struct nft_socket *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) + return -1; + if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) + return -1; + if (priv->key == NFT_SOCKET_CGROUPV2 && + nla_put_be32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level))) + return -1; + return 0; +} + +static bool nft_socket_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + const struct nft_socket *priv = nft_expr_priv(expr); + const struct nft_socket *socket; + + if (!nft_reg_track_cmp(track, expr, priv->dreg)) { + nft_reg_track_update(track, expr, priv->dreg, priv->len); + return false; + } + + socket = nft_expr_priv(track->regs[priv->dreg].selector); + if (priv->key != socket->key || + priv->dreg != socket->dreg || + priv->level != socket->level) { + nft_reg_track_update(track, expr, priv->dreg, priv->len); + return false; + } + + if (!track->regs[priv->dreg].bitwise) + return true; + + return nft_expr_reduce_bitwise(track, expr); +} + +static int nft_socket_validate(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nft_data **data) +{ + if (ctx->family != NFPROTO_IPV4 && + ctx->family != NFPROTO_IPV6 && + ctx->family != NFPROTO_INET) + return -EOPNOTSUPP; + + return nft_chain_validate_hooks(ctx->chain, + (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_LOCAL_IN) | + (1 << NF_INET_LOCAL_OUT)); +} + +static struct nft_expr_type nft_socket_type; +static const struct nft_expr_ops nft_socket_ops = { + .type = &nft_socket_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), + .eval = nft_socket_eval, + .init = nft_socket_init, + .dump = nft_socket_dump, + .validate = nft_socket_validate, + .reduce = nft_socket_reduce, +}; + +static struct nft_expr_type nft_socket_type __read_mostly = { + .name = "socket", + .ops = &nft_socket_ops, + .policy = nft_socket_policy, + .maxattr = NFTA_SOCKET_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_socket_module_init(void) +{ + return nft_register_expr(&nft_socket_type); +} + +static void __exit nft_socket_module_exit(void) +{ + nft_unregister_expr(&nft_socket_type); +} + +module_init(nft_socket_module_init); +module_exit(nft_socket_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Máté Eckl"); +MODULE_DESCRIPTION("nf_tables socket match module"); +MODULE_ALIAS_NFT_EXPR("socket"); |