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authorFlorian Westphal <fw@strlen.de>2023-04-21 20:02:54 +0300
committerAlexei Starovoitov <ast@kernel.org>2023-04-21 21:34:14 +0300
commit84601d6ee68ae820dec97450934797046d62db4b (patch)
tree62e6218db0097a338609e4ac44766a12a5c6b783 /include/uapi
parent45cea721ea36d83969473d2abd29bcc2321cacdd (diff)
downloadlinux-84601d6ee68ae820dec97450934797046d62db4b.tar.xz
bpf: add bpf_link support for BPF_NETFILTER programs
Add bpf_link support skeleton. To keep this reviewable, no bpf program can be invoked yet, if a program is attached only a c-stub is called and not the actual bpf program. Defaults to 'y' if both netfilter and bpf syscall are enabled in kconfig. Uapi example usage: union bpf_attr attr = { }; attr.link_create.prog_fd = progfd; attr.link_create.attach_type = 0; /* unused */ attr.link_create.netfilter.pf = PF_INET; attr.link_create.netfilter.hooknum = NF_INET_LOCAL_IN; attr.link_create.netfilter.priority = -128; err = bpf(BPF_LINK_CREATE, &attr, sizeof(attr)); ... this would attach progfd to ipv4:input hook. Such hook gets removed automatically if the calling program exits. BPF_NETFILTER program invocation is added in followup change. NF_HOOK_OP_BPF enum will eventually be read from nfnetlink_hook, it allows to tell userspace which program is attached at the given hook when user runs 'nft hook list' command rather than just the priority and not-very-helpful 'this hook runs a bpf prog but I can't tell which one'. Will also be used to disallow registration of two bpf programs with same priority in a followup patch. v4: arm32 cmpxchg only supports 32bit operand s/prio/priority/ v3: restrict prog attachment to ip/ip6 for now, lets lift restrictions if more use cases pop up (arptables, ebtables, netdev ingress/egress etc). Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/20230421170300.24115-2-fw@strlen.de Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/uapi')
-rw-r--r--include/uapi/linux/bpf.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4b20a7269bee..1bb11a6ee667 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -986,6 +986,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_LSM,
BPF_PROG_TYPE_SK_LOOKUP,
BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */
+ BPF_PROG_TYPE_NETFILTER,
};
enum bpf_attach_type {
@@ -1050,6 +1051,7 @@ enum bpf_link_type {
BPF_LINK_TYPE_PERF_EVENT = 7,
BPF_LINK_TYPE_KPROBE_MULTI = 8,
BPF_LINK_TYPE_STRUCT_OPS = 9,
+ BPF_LINK_TYPE_NETFILTER = 10,
MAX_BPF_LINK_TYPE,
};
@@ -1560,6 +1562,12 @@ union bpf_attr {
*/
__u64 cookie;
} tracing;
+ struct {
+ __u32 pf;
+ __u32 hooknum;
+ __s32 priority;
+ __u32 flags;
+ } netfilter;
};
} link_create;
@@ -6410,6 +6418,12 @@ struct bpf_link_info {
struct {
__u32 map_id;
} struct_ops;
+ struct {
+ __u32 pf;
+ __u32 hooknum;
+ __s32 priority;
+ __u32 flags;
+ } netfilter;
};
} __attribute__((aligned(8)));