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>
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index af2ca8b..7b6e5d1 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -40,6 +40,9 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk,
struct sk_buff *skb,
enum bpf_attach_type type);
+int __cgroup_bpf_run_filter_sk(struct sock *sk,
+ enum bpf_attach_type type);
+
/* Wrappers for __cgroup_bpf_run_filter_skb() guarded by cgroup_bpf_enabled. */
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \
({ \
@@ -63,6 +66,16 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk,
__ret; \
})
+#define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) \
+({ \
+ int __ret = 0; \
+ if (cgroup_bpf_enabled && sk) { \
+ __ret = __cgroup_bpf_run_filter_sk(sk, \
+ BPF_CGROUP_INET_SOCK_CREATE); \
+ } \
+ __ret; \
+})
+
#else
struct cgroup_bpf {};
@@ -72,6 +85,7 @@ static inline void cgroup_bpf_inherit(struct cgroup *cgrp,
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) ({ 0; })
#endif /* CONFIG_CGROUP_BPF */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 22ac827..bfe5e31 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -101,6 +101,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_XDP,
BPF_PROG_TYPE_PERF_EVENT,
BPF_PROG_TYPE_CGROUP_SKB,
+ BPF_PROG_TYPE_CGROUP_SOCK,
BPF_PROG_TYPE_LWT_IN,
BPF_PROG_TYPE_LWT_OUT,
BPF_PROG_TYPE_LWT_XMIT,
@@ -109,6 +110,7 @@ enum bpf_prog_type {
enum bpf_attach_type {
BPF_CGROUP_INET_INGRESS,
BPF_CGROUP_INET_EGRESS,
+ BPF_CGROUP_INET_SOCK_CREATE,
__MAX_BPF_ATTACH_TYPE
};
@@ -567,6 +569,10 @@ enum bpf_ret_code {
/* >127 are reserved for prog type specific return codes */
};
+struct bpf_sock {
+ __u32 bound_dev_if;
+};
+
/* User return codes for XDP prog type.
* A valid XDP program must return one of these defined values. All other
* return codes are reserved for future use. Unknown return codes will result