bpf: Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks

I have to now lock/unlock socket for the bind hook execution.
That shouldn't cause any overhead because the socket is unbound
and shouldn't receive any traffic.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/20201202172516.3483656-3-sdf@google.com

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index ed71bd1a082573ee3c579154b78fd9a6d6720f5c..72e69a0e1e8cc7cfedc2910552c93364842da377 100644 (file)
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -246,11 +246,11 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key,
        __ret;                                                                 \
 })
 
-#define BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr)                             \
-       BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_BIND)
+#define BPF_CGROUP_RUN_PROG_INET4_BIND_LOCK(sk, uaddr)                        \
+       BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET4_BIND, NULL)
 
-#define BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr)                             \
-       BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET6_BIND)
+#define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr)                        \
+       BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_BIND, NULL)
 
 #define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (cgroup_bpf_enabled && \
                                            sk->sk_prot->pre_connect)
@@ -434,8 +434,8 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map,
 #define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk) ({ 0; })
-#define BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr) ({ 0; })
-#define BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET4_BIND_LOCK(sk, uaddr) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk) ({ 0; })
 #define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) ({ 0; })

diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacfa7ffa142245d47b77699238e7132..21d91dcf0260c410f2813eacbddd107a92089a36 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6995,6 +6995,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                return &bpf_sk_storage_delete_proto;
        case BPF_FUNC_setsockopt:
                switch (prog->expected_attach_type) {
+               case BPF_CGROUP_INET4_BIND:
+               case BPF_CGROUP_INET6_BIND:
                case BPF_CGROUP_INET4_CONNECT:
                case BPF_CGROUP_INET6_CONNECT:
                        return &bpf_sock_addr_setsockopt_proto;
@@ -7003,6 +7005,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                }
        case BPF_FUNC_getsockopt:
                switch (prog->expected_attach_type) {
+               case BPF_CGROUP_INET4_BIND:
+               case BPF_CGROUP_INET6_BIND:
                case BPF_CGROUP_INET4_CONNECT:
                case BPF_CGROUP_INET6_CONNECT:
                        return &bpf_sock_addr_getsockopt_proto;

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index b7260c8cef2e5dea4c34b80e6728f85805dc40e9..b94fa8eb831bf3b18917529ef6a9263edb968592 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -450,7 +450,7 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
        /* BPF prog is run before any checks are done so that if the prog
         * changes context in a wrong way it will be caught.
         */
-       err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr);
+       err = BPF_CGROUP_RUN_PROG_INET4_BIND_LOCK(sk, uaddr);
        if (err)
                return err;
 

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index e648fbebb1670748de4b22a45356de306a0dc430..a7e3d170af51cc287a83d499299da6238b4b3f1e 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -451,7 +451,7 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
        /* BPF prog is run before any checks are done so that if the prog
         * changes context in a wrong way it will be caught.
         */
-       err = BPF_CGROUP_RUN_PROG_INET6_BIND(sk, uaddr);
+       err = BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr);
        if (err)
                return err;