3007098494
This patch adds two sets of eBPF program pointers to struct cgroup.
One for such that are directly pinned to a cgroup, and one for such
that are effective for it.
To illustrate the logic behind that, assume the following example
cgroup hierarchy.
A - B - C
\ D - E
If only B has a program attached, it will be effective for B, C, D
and E. If D then attaches a program itself, that will be effective for
both D and E, and the program in B will only affect B and C. Only one
program of a given type is effective for a cgroup.
Attaching and detaching programs will be done through the bpf(2)
syscall. For now, ingress and egress inet socket filtering are the
only supported use-cases.
Signed-off-by: Daniel Mack <daniel@zonque.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
80 lines
2.1 KiB
C
80 lines
2.1 KiB
C
#ifndef _BPF_CGROUP_H
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#define _BPF_CGROUP_H
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#include <linux/bpf.h>
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#include <linux/jump_label.h>
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#include <uapi/linux/bpf.h>
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struct sock;
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struct cgroup;
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struct sk_buff;
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#ifdef CONFIG_CGROUP_BPF
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extern struct static_key_false cgroup_bpf_enabled_key;
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#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key)
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struct cgroup_bpf {
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/*
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* Store two sets of bpf_prog pointers, one for programs that are
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* pinned directly to this cgroup, and one for those that are effective
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* when this cgroup is accessed.
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*/
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struct bpf_prog *prog[MAX_BPF_ATTACH_TYPE];
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struct bpf_prog *effective[MAX_BPF_ATTACH_TYPE];
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};
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void cgroup_bpf_put(struct cgroup *cgrp);
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void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent);
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void __cgroup_bpf_update(struct cgroup *cgrp,
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struct cgroup *parent,
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struct bpf_prog *prog,
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enum bpf_attach_type type);
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/* Wrapper for __cgroup_bpf_update() protected by cgroup_mutex */
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void cgroup_bpf_update(struct cgroup *cgrp,
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struct bpf_prog *prog,
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enum bpf_attach_type type);
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int __cgroup_bpf_run_filter(struct sock *sk,
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struct sk_buff *skb,
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enum bpf_attach_type type);
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/* Wrappers for __cgroup_bpf_run_filter() guarded by cgroup_bpf_enabled. */
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#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) \
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({ \
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int __ret = 0; \
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if (cgroup_bpf_enabled) \
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__ret = __cgroup_bpf_run_filter(sk, skb, \
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BPF_CGROUP_INET_INGRESS); \
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\
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__ret; \
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})
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#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) \
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({ \
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int __ret = 0; \
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if (cgroup_bpf_enabled && sk && sk == skb->sk) { \
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typeof(sk) __sk = sk_to_full_sk(sk); \
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if (sk_fullsock(__sk)) \
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__ret = __cgroup_bpf_run_filter(__sk, skb, \
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BPF_CGROUP_INET_EGRESS); \
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} \
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__ret; \
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})
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#else
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struct cgroup_bpf {};
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static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
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static inline void cgroup_bpf_inherit(struct cgroup *cgrp,
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struct cgroup *parent) {}
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#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
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#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })
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#endif /* CONFIG_CGROUP_BPF */
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#endif /* _BPF_CGROUP_H */
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