diff options
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/Makefile | 6 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_bpf.c | 74 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_core.c | 1 | ||||
| -rw-r--r-- | net/netfilter/nf_nat_bpf.c | 79 | ||||
| -rw-r--r-- | net/netfilter/nf_nat_core.c | 4 |
5 files changed, 155 insertions, 9 deletions
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 06df49ea6329..0f060d100880 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -60,6 +60,12 @@ obj-$(CONFIG_NF_NAT) += nf_nat.o nf_nat-$(CONFIG_NF_NAT_REDIRECT) += nf_nat_redirect.o nf_nat-$(CONFIG_NF_NAT_MASQUERADE) += nf_nat_masquerade.o +ifeq ($(CONFIG_NF_NAT),m) +nf_nat-$(CONFIG_DEBUG_INFO_BTF_MODULES) += nf_nat_bpf.o +else ifeq ($(CONFIG_NF_NAT),y) +nf_nat-$(CONFIG_DEBUG_INFO_BTF) += nf_nat_bpf.o +endif + # NAT helpers obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_amanda.o obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c index 1cd87b28c9b0..8639e7efd0e2 100644 --- a/net/netfilter/nf_conntrack_bpf.c +++ b/net/netfilter/nf_conntrack_bpf.c @@ -6,12 +6,14 @@ * are exposed through to BPF programs is explicitly unstable. */ +#include <linux/bpf_verifier.h> #include <linux/bpf.h> #include <linux/btf.h> +#include <linux/filter.h> +#include <linux/mutex.h> #include <linux/types.h> #include <linux/btf_ids.h> #include <linux/net_namespace.h> -#include <net/netfilter/nf_conntrack.h> #include <net/netfilter/nf_conntrack_bpf.h> #include <net/netfilter/nf_conntrack_core.h> @@ -134,7 +136,6 @@ __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) @@ -184,14 +185,58 @@ static struct nf_conn *__bpf_nf_ct_lookup(struct net *net, return ct; } +BTF_ID_LIST(btf_nf_conn_ids) +BTF_ID(struct, nf_conn) +BTF_ID(struct, nf_conn___init) + +/* Check writes into `struct nf_conn` */ +static int _nf_conntrack_btf_struct_access(struct bpf_verifier_log *log, + const struct btf *btf, + const struct btf_type *t, int off, + int size, enum bpf_access_type atype, + u32 *next_btf_id, + enum bpf_type_flag *flag) +{ + const struct btf_type *ncit; + const struct btf_type *nct; + size_t end; + + ncit = btf_type_by_id(btf, btf_nf_conn_ids[1]); + nct = btf_type_by_id(btf, btf_nf_conn_ids[0]); + + if (t != nct && t != ncit) { + bpf_log(log, "only read is supported\n"); + return -EACCES; + } + + /* `struct nf_conn` and `struct nf_conn___init` have the same layout + * so we are safe to simply merge offset checks here + */ + switch (off) { +#if defined(CONFIG_NF_CONNTRACK_MARK) + case offsetof(struct nf_conn, mark): + end = offsetofend(struct nf_conn, mark); + break; +#endif + default: + bpf_log(log, "no write support to nf_conn at off %d\n", off); + return -EACCES; + } + + if (off + size > end) { + bpf_log(log, + "write access at off %d with size %d beyond the member of nf_conn ended at %zu\n", + off, size, end); + return -EACCES; + } + + return 0; +} + __diag_push(); __diag_ignore_all("-Wmissing-prototypes", "Global functions as their definitions will be in nf_conntrack BTF"); -struct nf_conn___init { - struct nf_conn ct; -}; - /* bpf_xdp_ct_alloc - Allocate a new CT entry * * Parameters: @@ -339,6 +384,7 @@ 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); @@ -449,5 +495,19 @@ int register_nf_conntrack_bpf(void) int ret; ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &nf_conntrack_kfunc_set); - return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_kfunc_set); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_kfunc_set); + if (!ret) { + mutex_lock(&nf_conn_btf_access_lock); + nfct_btf_struct_access = _nf_conntrack_btf_struct_access; + mutex_unlock(&nf_conn_btf_access_lock); + } + + return ret; +} + +void cleanup_nf_conntrack_bpf(void) +{ + mutex_lock(&nf_conn_btf_access_lock); + nfct_btf_struct_access = NULL; + mutex_unlock(&nf_conn_btf_access_lock); } diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8208a28ea342..f97bda06d2a9 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2516,6 +2516,7 @@ static int kill_all(struct nf_conn *i, void *data) void nf_conntrack_cleanup_start(void) { + cleanup_nf_conntrack_bpf(); conntrack_gc_work.exiting = true; } diff --git a/net/netfilter/nf_nat_bpf.c b/net/netfilter/nf_nat_bpf.c new file mode 100644 index 000000000000..0fa5a0bbb0ff --- /dev/null +++ b/net/netfilter/nf_nat_bpf.c @@ -0,0 +1,79 @@ +// 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> + +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "Global functions as their definitions will be in nf_nat BTF"); + +/* 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) +{ + 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; +} + +__diag_pop() + +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); +} diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 7981be526f26..d8e6380f6337 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -16,7 +16,7 @@ #include <linux/siphash.h> #include <linux/rtnetlink.h> -#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_bpf.h> #include <net/netfilter/nf_conntrack_core.h> #include <net/netfilter/nf_conntrack_helper.h> #include <net/netfilter/nf_conntrack_seqadj.h> @@ -1152,7 +1152,7 @@ static int __init nf_nat_init(void) WARN_ON(nf_nat_hook != NULL); RCU_INIT_POINTER(nf_nat_hook, &nat_hook); - return 0; + return register_nf_nat_bpf(); } static void __exit nf_nat_cleanup(void) |