Stanislav Fomichev <s...@google.com> [Thu, 2019-01-17 16:41 -0800]:
> These hooks mirror existing BPF_CGROUP_INET{4,6}_SOCK hooks (which
> trigger upon socket creation), but trigger when the socket is closed.
>
> Signed-off-by: Stanislav Fomichev <s...@google.com>
> ---
> include/linux/bpf-cgroup.h | 6 ++++++
> include/net/inet_common.h | 1 +
> include/uapi/linux/bpf.h | 2 ++
> kernel/bpf/syscall.c | 8 ++++++++
> net/core/filter.c | 7 +++++++
> net/ipv4/af_inet.c | 13 ++++++++++++-
> net/ipv6/af_inet6.c | 5 ++++-
> 7 files changed, 40 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
> index 588dd5f0bd85..31fcfe215d80 100644
> --- a/include/linux/bpf-cgroup.h
> +++ b/include/linux/bpf-cgroup.h
> @@ -176,6 +176,12 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map
> *map, void *key,
> #define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) \
> BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET_SOCK_CREATE)
>
> +#define BPF_CGROUP_RUN_PROG_INET4_SOCK_RELEASE(sk) \
> + BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET4_SOCK_RELEASE)
> +
> +#define BPF_CGROUP_RUN_PROG_INET6_SOCK_RELEASE(sk) \
> + BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET6_SOCK_RELEASE)
> +
> #define BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk)
> \
> BPF_CGROUP_RUN_SK_PROG(sk, BPF_CGROUP_INET4_POST_BIND)
These macros should also be defined for the case when CONFIG_CGROUP_BPF
is not set. See in this file below:
#define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) ({ 0; })
> diff --git a/include/net/inet_common.h b/include/net/inet_common.h
> index 975901a95c0f..0e64046afe30 100644
> --- a/include/net/inet_common.h
> +++ b/include/net/inet_common.h
> @@ -17,6 +17,7 @@ struct sockaddr;
> struct socket;
>
> int inet_release(struct socket *sock);
> +int __inet_release(struct socket *sock);
> int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
> int addr_len, int flags);
> int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 91c43884f295..8e78aa28a42e 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -186,6 +186,8 @@ enum bpf_attach_type {
> BPF_CGROUP_UDP6_SENDMSG,
> BPF_LIRC_MODE2,
> BPF_FLOW_DISSECTOR,
> + BPF_CGROUP_INET4_SOCK_RELEASE,
> + BPF_CGROUP_INET6_SOCK_RELEASE,
> __MAX_BPF_ATTACH_TYPE
> };
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index b155cd17c1bd..6fa113448580 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -1417,6 +1417,8 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type
> prog_type,
> case BPF_PROG_TYPE_CGROUP_SOCK:
> switch (expected_attach_type) {
> case BPF_CGROUP_INET_SOCK_CREATE:
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> case BPF_CGROUP_INET4_POST_BIND:
> case BPF_CGROUP_INET6_POST_BIND:
> return 0;
> @@ -1709,6 +1711,8 @@ static int bpf_prog_attach(const union bpf_attr *attr)
> ptype = BPF_PROG_TYPE_CGROUP_SKB;
> break;
> case BPF_CGROUP_INET_SOCK_CREATE:
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> case BPF_CGROUP_INET4_POST_BIND:
> case BPF_CGROUP_INET6_POST_BIND:
> ptype = BPF_PROG_TYPE_CGROUP_SOCK;
> @@ -1791,6 +1795,8 @@ static int bpf_prog_detach(const union bpf_attr *attr)
> ptype = BPF_PROG_TYPE_CGROUP_SKB;
> break;
> case BPF_CGROUP_INET_SOCK_CREATE:
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> case BPF_CGROUP_INET4_POST_BIND:
> case BPF_CGROUP_INET6_POST_BIND:
> ptype = BPF_PROG_TYPE_CGROUP_SOCK;
> @@ -1841,6 +1847,8 @@ static int bpf_prog_query(const union bpf_attr *attr,
> case BPF_CGROUP_INET_INGRESS:
> case BPF_CGROUP_INET_EGRESS:
> case BPF_CGROUP_INET_SOCK_CREATE:
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> case BPF_CGROUP_INET4_BIND:
> case BPF_CGROUP_INET6_BIND:
> case BPF_CGROUP_INET4_POST_BIND:
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 2b3b436ef545..b4da6793fdbc 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -5885,12 +5885,16 @@ static bool __sock_filter_check_attach_type(int off,
> switch (attach_type) {
> case BPF_CGROUP_INET_SOCK_CREATE:
> goto full_access;
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> + goto read_only;
> default:
> return false;
> }
> case bpf_ctx_range(struct bpf_sock, src_ip4):
> switch (attach_type) {
> case BPF_CGROUP_INET4_POST_BIND:
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> goto read_only;
> default:
> return false;
> @@ -5898,6 +5902,7 @@ static bool __sock_filter_check_attach_type(int off,
> case bpf_ctx_range_till(struct bpf_sock, src_ip6[0], src_ip6[3]):
> switch (attach_type) {
> case BPF_CGROUP_INET6_POST_BIND:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> goto read_only;
> default:
> return false;
> @@ -5906,6 +5911,8 @@ static bool __sock_filter_check_attach_type(int off,
> switch (attach_type) {
> case BPF_CGROUP_INET4_POST_BIND:
> case BPF_CGROUP_INET6_POST_BIND:
> + case BPF_CGROUP_INET4_SOCK_RELEASE:
> + case BPF_CGROUP_INET6_SOCK_RELEASE:
> goto read_only;
> default:
> return false;
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index 0dfb72c46671..b703ad242365 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -403,7 +403,7 @@ static int inet_create(struct net *net, struct socket
> *sock, int protocol,
> * function we are destroying the object and from then on nobody
> * should refer to it.
> */
> -int inet_release(struct socket *sock)
> +int __inet_release(struct socket *sock)
> {
> struct sock *sk = sock->sk;
>
> @@ -429,6 +429,17 @@ int inet_release(struct socket *sock)
> }
> return 0;
> }
> +EXPORT_SYMBOL(__inet_release);
> +
> +int inet_release(struct socket *sock)
> +{
> + struct sock *sk = sock->sk;
> +
> + if (sk && !sk->sk_kern_sock)
> + BPF_CGROUP_RUN_PROG_INET4_SOCK_RELEASE(sk);
> +
> + return __inet_release(sock);
> +}
> EXPORT_SYMBOL(inet_release);
>
> int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
> diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
> index d99753b5e39b..44c86595eba8 100644
> --- a/net/ipv6/af_inet6.c
> +++ b/net/ipv6/af_inet6.c
> @@ -464,13 +464,16 @@ int inet6_release(struct socket *sock)
> if (!sk)
> return -EINVAL;
>
> + if (!sk->sk_kern_sock)
> + BPF_CGROUP_RUN_PROG_INET6_SOCK_RELEASE(sock->sk);
Nit: s/sock->sk/sk/
> +
> /* Free mc lists */
> ipv6_sock_mc_close(sk);
>
> /* Free ac lists */
> ipv6_sock_ac_close(sk);
>
> - return inet_release(sock);
> + return __inet_release(sock);
> }
> EXPORT_SYMBOL(inet6_release);
>
> --
> 2.20.1.321.g9e740568ce-goog
>
--
Andrey Ignatov
