From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
Currently sockmap calls into each protocol to update the struct
proto and replace it. This certainly won't work when the protocol
is implemented as a module, for example, AF_UNIX.
Introduce a new ops sk->sk_prot->update_proto(), so each protocol
can implement its own way to replace the struct proto.
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
Cc: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
---
include/linux/skmsg.h | 18 +++---------------
include/net/sock.h | 3 +++
include/net/tcp.h | 2 +-
include/net/udp.h | 2 +-
net/core/sock_map.c | 22 +++-------------------
net/ipv4/tcp_bpf.c | 20 +++++++++++++++++---
net/ipv4/tcp_ipv4.c | 3 +++
net/ipv4/udp.c | 3 +++
net/ipv4/udp_bpf.c | 14 ++++++++++++--
net/ipv6/tcp_ipv6.c | 3 +++
net/ipv6/udp.c | 3 +++
11 files changed, 52 insertions(+), 41 deletions(-)
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index cb79b1afa556..cb94d0f89c08 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -97,6 +97,7 @@ struct sk_psock {
void (*saved_close)(struct sock *sk, long timeout);
void (*saved_write_space)(struct sock *sk);
void (*saved_data_ready)(struct sock *sk);
+ int (*saved_update_proto)(struct sock *sk, bool restore);
struct proto *sk_proto;
struct sk_psock_work_state work_state;
struct work_struct work;
@@ -335,25 +336,12 @@ static inline void sk_psock_cork_free(struct sk_psock *psock)
}
}
-static inline void sk_psock_update_proto(struct sock *sk,
- struct sk_psock *psock,
- struct proto *ops)
-{
- /* Pairs with lockless read in sk_clone_lock() */
- WRITE_ONCE(sk->sk_prot, ops);
-}
-
static inline void sk_psock_restore_proto(struct sock *sk,
struct sk_psock *psock)
{
sk->sk_prot->unhash = psock->saved_unhash;
- if (inet_csk_has_ulp(sk)) {
- tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space);
- } else {
- sk->sk_write_space = psock->saved_write_space;
- /* Pairs with lockless read in sk_clone_lock() */
- WRITE_ONCE(sk->sk_prot, psock->sk_proto);
- }
+ if (psock->saved_update_proto)
+ psock->saved_update_proto(sk, true);
}
static inline void sk_psock_set_state(struct sk_psock *psock,
diff --git a/include/net/sock.h b/include/net/sock.h
index 7644ea64a376..e474a9202be8 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1184,6 +1184,9 @@ struct proto {
void (*unhash)(struct sock *sk);
void (*rehash)(struct sock *sk);
int (*get_port)(struct sock *sk, unsigned short snum);
+#ifdef CONFIG_BPF_SOCK_MAP
+ int (*update_proto)(struct sock *sk, bool restore);
+#endif
/* Keeping track of sockets in use */
#ifdef CONFIG_PROC_FS
diff --git a/include/net/tcp.h b/include/net/tcp.h
index f7591768525d..c2fff35859b6 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2183,7 +2183,7 @@ struct sk_msg;
struct sk_psock;
#ifdef CONFIG_BPF_SOCK_MAP
-struct proto *tcp_bpf_get_proto(struct sock *sk, struct sk_psock *psock);
+int tcp_bpf_update_proto(struct sock *sk, bool restore);
void tcp_bpf_clone(const struct sock *sk, struct sock *newsk);
#else
static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
diff --git a/include/net/udp.h b/include/net/udp.h
index 0ff921e6b866..e3e5dfc8e0f0 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -513,7 +513,7 @@ static inline struct sk_buff *udp_rcv_segment(struct sock *sk,
#ifdef CONFIG_BPF_SOCK_MAP
struct sk_psock;
-struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock);
+int udp_bpf_update_proto(struct sock *sk, bool restore);
#endif /* CONFIG_BPF_SOCK_MAP */
#endif /* _UDP_H */
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index f827f1ecefcc..255067e5c73a 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -181,26 +181,10 @@ static void sock_map_unref(struct sock *sk, void *link_raw)
static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
{
- struct proto *prot;
-
- switch (sk->sk_type) {
- case SOCK_STREAM:
- prot = tcp_bpf_get_proto(sk, psock);
- break;
-
- case SOCK_DGRAM:
- prot = udp_bpf_get_proto(sk, psock);
- break;
-
- default:
+ if (!sk->sk_prot->update_proto)
return -EINVAL;
- }
-
- if (IS_ERR(prot))
- return PTR_ERR(prot);
-
- sk_psock_update_proto(sk, psock, prot);
- return 0;
+ psock->saved_update_proto = sk->sk_prot->update_proto;
+ return sk->sk_prot->update_proto(sk, false);
}
static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 2252f1d90676..16e00802ccba 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -601,19 +601,33 @@ static int tcp_bpf_assert_proto_ops(struct proto *ops)
ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP;
}
-struct proto *tcp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
+int tcp_bpf_update_proto(struct sock *sk, bool restore)
{
+ struct sk_psock *psock = sk_psock(sk);
int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
+ if (restore) {
+ if (inet_csk_has_ulp(sk)) {
+ tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space);
+ } else {
+ sk->sk_write_space = psock->saved_write_space;
+ /* Pairs with lockless read in sk_clone_lock() */
+ WRITE_ONCE(sk->sk_prot, psock->sk_proto);
+ }
+ return 0;
+ }
+
if (sk->sk_family == AF_INET6) {
if (tcp_bpf_assert_proto_ops(psock->sk_proto))
- return ERR_PTR(-EINVAL);
+ return -EINVAL;
tcp_bpf_check_v6_needs_rebuild(psock->sk_proto);
}
- return &tcp_bpf_prots[family][config];
+ /* Pairs with lockless read in sk_clone_lock() */
+ WRITE_ONCE(sk->sk_prot, &tcp_bpf_prots[family][config]);
+ return 0;
}
/* If a child got cloned from a listening socket that had tcp_bpf
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 62b6fd385a47..d7c30b762cc3 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2803,6 +2803,9 @@ struct proto tcp_prot = {
.hash = inet_hash,
.unhash = inet_unhash,
.get_port = inet_csk_get_port,
+#ifdef CONFIG_BPF_SOCK_MAP
+ .update_proto = tcp_bpf_update_proto,
+#endif
.enter_memory_pressure = tcp_enter_memory_pressure,
.leave_memory_pressure = tcp_leave_memory_pressure,
.stream_memory_free = tcp_stream_memory_free,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c67e483fce41..84ab4f2e874a 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2843,6 +2843,9 @@ struct proto udp_prot = {
.unhash = udp_lib_unhash,
.rehash = udp_v4_rehash,
.get_port = udp_v4_get_port,
+#ifdef CONFIG_BPF_SOCK_MAP
+ .update_proto = udp_bpf_update_proto,
+#endif
.memory_allocated = &udp_memory_allocated,
.sysctl_mem = sysctl_udp_mem,
.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
index 7a94791efc1a..595836088e85 100644
--- a/net/ipv4/udp_bpf.c
+++ b/net/ipv4/udp_bpf.c
@@ -41,12 +41,22 @@ static int __init udp_bpf_v4_build_proto(void)
}
core_initcall(udp_bpf_v4_build_proto);
-struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
+int udp_bpf_update_proto(struct sock *sk, bool restore)
{
int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
+ struct sk_psock *psock = sk_psock(sk);
+
+ if (restore) {
+ sk->sk_write_space = psock->saved_write_space;
+ /* Pairs with lockless read in sk_clone_lock() */
+ WRITE_ONCE(sk->sk_prot, psock->sk_proto);
+ return 0;
+ }
if (sk->sk_family == AF_INET6)
udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
- return &udp_bpf_prots[family];
+ /* Pairs with lockless read in sk_clone_lock() */
+ WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]);
+ return 0;
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 8539715ff035..77b11799a3fe 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2131,6 +2131,9 @@ struct proto tcpv6_prot = {
.hash = inet6_hash,
.unhash = inet_unhash,
.get_port = inet_csk_get_port,
+#ifdef CONFIG_BPF_SOCK_MAP
+ .update_proto = tcp_bpf_update_proto,
+#endif
.enter_memory_pressure = tcp_enter_memory_pressure,
.leave_memory_pressure = tcp_leave_memory_pressure,
.stream_memory_free = tcp_stream_memory_free,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index a02ac875a923..66ebdfc83c95 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1711,6 +1711,9 @@ struct proto udpv6_prot = {
.unhash = udp_lib_unhash,
.rehash = udp_v6_rehash,
.get_port = udp_v6_get_port,
+#ifdef CONFIG_BPF_SOCK_MAP
+ .update_proto = udp_bpf_update_proto,
+#endif
.memory_allocated = &udp_memory_allocated,
.sysctl_mem = sysctl_udp_mem,
.sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
--
2.25.1
