bpf: Add new cgroup attach type to enable sock modifications
Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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committed by
David S. Miller

parent
b2cd12574a
commit
6102365876
@@ -165,3 +165,36 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk,
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return ret;
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}
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EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
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/**
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* __cgroup_bpf_run_filter_sk() - Run a program on a sock
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* @sk: sock structure to manipulate
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* @type: The type of program to be exectuted
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*
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* socket is passed is expected to be of type INET or INET6.
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*
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* The program type passed in via @type must be suitable for sock
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* filtering. No further check is performed to assert that.
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*
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* This function will return %-EPERM if any if an attached program was found
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* and if it returned != 1 during execution. In all other cases, 0 is returned.
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*/
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int __cgroup_bpf_run_filter_sk(struct sock *sk,
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enum bpf_attach_type type)
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{
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struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
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struct bpf_prog *prog;
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int ret = 0;
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rcu_read_lock();
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prog = rcu_dereference(cgrp->bpf.effective[type]);
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if (prog)
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ret = BPF_PROG_RUN(prog, sk) == 1 ? 0 : -EPERM;
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rcu_read_unlock();
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return ret;
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}
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EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
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