From 0fabd2aa199faeb8754aee94658f2c48ccb2c8c3 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Wed, 21 Sep 2022 18:48:26 +0200 Subject: net: netfilter: add bpf_ct_set_nat_info kfunc helper Introduce bpf_ct_set_nat_info kfunc helper in order to set source and destination nat addresses/ports in a new allocated ct entry not inserted in the connection tracking table yet. Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/9567db2fdfa5bebe7b7cc5870f7a34549418b4fc.1663778601.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov --- net/netfilter/nf_conntrack_bpf.c | 47 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) (limited to 'net/netfilter') diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c index 67df64283aef..756ea818574e 100644 --- a/net/netfilter/nf_conntrack_bpf.c +++ b/net/netfilter/nf_conntrack_bpf.c @@ -17,6 +17,7 @@ #include #include #include +#include /* bpf_ct_opts - Options for CT lookup helpers * @@ -137,7 +138,6 @@ __bpf_nf_ct_alloc_entry(struct net *net, struct bpf_sock_tuple *bpf_tuple, memset(&ct->proto, 0, sizeof(ct->proto)); __nf_ct_set_timeout(ct, timeout * HZ); - ct->status |= IPS_CONFIRMED; out: if (opts->netns_id >= 0) @@ -390,6 +390,7 @@ struct nf_conn *bpf_ct_insert_entry(struct nf_conn___init *nfct_i) struct nf_conn *nfct = (struct nf_conn *)nfct_i; int err; + nfct->status |= IPS_CONFIRMED; err = nf_conntrack_hash_check_insert(nfct); if (err < 0) { nf_conntrack_free(nfct); @@ -475,6 +476,49 @@ int bpf_ct_change_status(struct nf_conn *nfct, u32 status) return nf_ct_change_status_common(nfct, status); } +/* bpf_ct_set_nat_info - Set source or destination nat address + * + * Set source or destination nat address of the newly allocated + * nf_conn before insertion. This must be invoked for referenced + * PTR_TO_BTF_ID to nf_conn___init. + * + * Parameters: + * @nfct - Pointer to referenced nf_conn object, obtained using + * bpf_xdp_ct_alloc or bpf_skb_ct_alloc. + * @addr - Nat source/destination address + * @port - Nat source/destination port. Non-positive values are + * interpreted as select a random port. + * @manip - NF_NAT_MANIP_SRC or NF_NAT_MANIP_DST + */ +int bpf_ct_set_nat_info(struct nf_conn___init *nfct, + union nf_inet_addr *addr, int port, + enum nf_nat_manip_type manip) +{ +#if ((IS_MODULE(CONFIG_NF_NAT) && IS_MODULE(CONFIG_NF_CONNTRACK)) || \ + IS_BUILTIN(CONFIG_NF_NAT)) + struct nf_conn *ct = (struct nf_conn *)nfct; + u16 proto = nf_ct_l3num(ct); + struct nf_nat_range2 range; + + if (proto != NFPROTO_IPV4 && proto != NFPROTO_IPV6) + return -EINVAL; + + memset(&range, 0, sizeof(struct nf_nat_range2)); + range.flags = NF_NAT_RANGE_MAP_IPS; + range.min_addr = *addr; + range.max_addr = range.min_addr; + if (port > 0) { + range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; + range.min_proto.all = cpu_to_be16(port); + range.max_proto.all = range.min_proto.all; + } + + return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0; +#else + return -EOPNOTSUPP; +#endif +} + __diag_pop() BTF_SET8_START(nf_ct_kfunc_set) @@ -488,6 +532,7 @@ BTF_ID_FLAGS(func, bpf_ct_set_timeout, KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_ct_change_timeout, KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_ct_set_status, KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_ct_change_status, KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_ct_set_nat_info, KF_TRUSTED_ARGS) BTF_SET8_END(nf_ct_kfunc_set) static const struct btf_kfunc_id_set nf_conntrack_kfunc_set = { -- cgit v1.2.3-59-g8ed1b