Add basic psock hooks for UDP sockets. This allows adding and
removing sockets, as well as automatic removal on unhash and close.
Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
---
MAINTAINERS | 1 +
include/linux/udp.h | 4 ++++
net/core/sock_map.c | 47 +++++++++++++++++++++++-----------------
net/ipv4/Makefile | 1 +
net/ipv4/udp_bpf.c | 53 +++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 86 insertions(+), 20 deletions(-)
create mode 100644 net/ipv4/udp_bpf.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 2af5fa73155e..495ba52038ad 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9358,6 +9358,7 @@ F: include/linux/skmsg.h
F: net/core/skmsg.c
F: net/core/sock_map.c
F: net/ipv4/tcp_bpf.c
+F: net/ipv4/udp_bpf.c
LANTIQ / INTEL Ethernet drivers
M: Hauke Mehrtens <hauke@xxxxxxxxxx>
diff --git a/include/linux/udp.h b/include/linux/udp.h
index aa84597bdc33..d90d8fd5f73d 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -143,4 +143,8 @@ static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
+#if defined(CONFIG_NET_SOCK_MSG)
+int udp_bpf_init(struct sock *sk);
+#endif
+
#endif /* _LINUX_UDP_H */
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index c84cc9fc7f6b..f998192c425f 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -153,7 +153,7 @@ static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
rcu_read_lock();
psock = sk_psock(sk);
if (psock) {
- if (sk->sk_prot->recvmsg != tcp_bpf_recvmsg) {
+ if (sk->sk_prot->close != sock_map_close) {
psock = ERR_PTR(-EBUSY);
goto out;
}
@@ -166,6 +166,14 @@ static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
return psock;
}
+static int sock_map_init_hooks(struct sock *sk)
+{
+ if (sk->sk_type == SOCK_DGRAM)
+ return udp_bpf_init(sk);
+ else
+ return tcp_bpf_init(sk);
+}
+
static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
struct sock *sk)
{
@@ -220,7 +228,7 @@ static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
if (msg_parser)
psock_set_prog(&psock->progs.msg_parser, msg_parser);
- ret = tcp_bpf_init(sk);
+ ret = sock_map_init_hooks(sk);
if (ret < 0)
goto out_drop;
@@ -267,7 +275,7 @@ static int sock_map_link_no_progs(struct bpf_map *map, struct sock *sk)
return -ENOMEM;
init:
- ret = tcp_bpf_init(sk);
+ ret = sock_map_init_hooks(sk);
if (ret < 0)
sk_psock_put(sk, psock);
return ret;
@@ -394,9 +402,14 @@ static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
return 0;
}
+static bool sock_map_sk_is_tcp(const struct sock *sk)
+{
+ return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
+}
+
static bool sock_map_redirect_allowed(const struct sock *sk)
{
- return sk->sk_state != TCP_LISTEN;
+ return sock_map_sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
}
static int sock_map_update_common(struct bpf_map *map, u32 idx,
@@ -466,15 +479,17 @@ static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
}
+static bool sock_map_sk_is_udp(const struct sock *sk)
+{
+ return sk->sk_type == SOCK_DGRAM && sk->sk_protocol == IPPROTO_UDP;
+}
+
static bool sock_map_sk_is_suitable(const struct sock *sk)
{
- return sk->sk_type == SOCK_STREAM &&
- sk->sk_protocol == IPPROTO_TCP;
-}
+ const int tcp_flags = TCPF_ESTABLISHED | TCPF_LISTEN | TCPF_SYN_RECV;
-static bool sock_map_sk_state_allowed(const struct sock *sk)
-{
- return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
+ return (sock_map_sk_is_udp(sk) && sk_hashed(sk)) ||
+ (sock_map_sk_is_tcp(sk) && (1 << sk->sk_state) & tcp_flags);
}
static int sock_map_update_elem(struct bpf_map *map, void *key,
@@ -501,13 +516,9 @@ static int sock_map_update_elem(struct bpf_map *map, void *key,
ret = -EINVAL;
goto out;
}
- if (!sock_map_sk_is_suitable(sk)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
sock_map_sk_acquire(sk);
- if (!sock_map_sk_state_allowed(sk))
+ if (!sock_map_sk_is_suitable(sk))
ret = -EOPNOTSUPP;
else
ret = sock_map_update_common(map, idx, sk, flags);
@@ -849,13 +860,9 @@ static int sock_hash_update_elem(struct bpf_map *map, void *key,
ret = -EINVAL;
goto out;
}
- if (!sock_map_sk_is_suitable(sk)) {
- ret = -EOPNOTSUPP;
- goto out;
- }
sock_map_sk_acquire(sk);
- if (!sock_map_sk_state_allowed(sk))
+ if (!sock_map_sk_is_suitable(sk))
ret = -EOPNOTSUPP;
else
ret = sock_hash_update_common(map, key, sk, flags);
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 9d97bace13c8..48cc05d365e4 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o
+obj-$(CONFIG_NET_SOCK_MSG) += udp_bpf.o
obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
new file mode 100644
index 000000000000..e085a0648a94
--- /dev/null
+++ b/net/ipv4/udp_bpf.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */
+
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/init.h>
+#include <linux/skmsg.h>
+#include <linux/wait.h>
+#include <net/udp.h>
+
+#include <net/inet_common.h>
+
+static int udp_bpf_rebuild_protos(struct proto *prot, struct proto *base)
+{
+ *prot = *base;
+ prot->unhash = sock_map_unhash;
+ prot->close = sock_map_close;
+ return 0;
+}
+
+static struct proto *udp_bpf_choose_proto(struct proto prot[],
+ struct sk_psock *psock)
+{
+ return prot;
+}
+
+static struct proto udpv4_proto;
+static struct proto udpv6_proto;
+
+static struct sk_psock_hooks udp_psock_proto __read_mostly = {
+ .ipv4 = &udpv4_proto,
+ .ipv6 = &udpv6_proto,
+ .rebuild_proto = udp_bpf_rebuild_protos,
+ .choose_proto = udp_bpf_choose_proto,
+};
+
+static int __init udp_bpf_init_psock_hooks(void)
+{
+ return sk_psock_hooks_init(&udp_psock_proto, &udp_prot);
+}
+core_initcall(udp_bpf_init_psock_hooks);
+
+int udp_bpf_init(struct sock *sk)
+{
+ int ret;
+
+ sock_owned_by_me(sk);
+
+ rcu_read_lock();
+ ret = sk_psock_hooks_install(&udp_psock_proto, sk);
+ rcu_read_unlock();
+ return ret;
+}
--
2.20.1
