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// SPDX-License-Identifier: GPL-2.0-only /* Unstable NAT Helpers for XDP and TC-BPF hook * * These are called from the XDP and SCHED_CLS BPF programs. Note that it is * allowed to break compatibility for these functions since the interface they * are exposed through to BPF programs is explicitly unstable. */ #include <linux/bpf.h> #include <linux/btf_ids.h> #include <net/netfilter/nf_conntrack_bpf.h> #include <net/netfilter/nf_conntrack_core.h> #include <net/netfilter/nf_nat.h> __bpf_kfunc_start_defs(); /* 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 */ __bpf_kfunc int bpf_ct_set_nat_info(struct nf_conn___init *nfct, union nf_inet_addr *addr, int port, enum nf_nat_manip_type manip) { 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; } __bpf_kfunc_end_defs(); BTF_SET8_START(nf_nat_kfunc_set) BTF_ID_FLAGS(func, bpf_ct_set_nat_info, KF_TRUSTED_ARGS) BTF_SET8_END(nf_nat_kfunc_set) static const struct btf_kfunc_id_set nf_bpf_nat_kfunc_set = { .owner = THIS_MODULE, .set = &nf_nat_kfunc_set, }; int register_nf_nat_bpf(void) { int ret; ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &nf_bpf_nat_kfunc_set); if (ret) return ret; return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_bpf_nat_kfunc_set); } |