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authorLorenz Bauer <lmb@cloudflare.com>2020-03-09 11:12:38 +0000
committerDaniel Borkmann <daniel@iogearbox.net>2020-03-09 22:34:58 +0100
commitedc6741cc66059532ba621928e3f1b02a53a2f39 (patch)
treecefa40db3ea5e03a027f2ab6e0299f8e80c6a159 /net/ipv4/udp_bpf.c
parentcb21802b39632ba1fa9b31ea134d2079a47600ef (diff)
bpf: Add sockmap hooks for UDP sockets
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@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200309111243.6982-8-lmb@cloudflare.com
Diffstat (limited to 'net/ipv4/udp_bpf.c')
-rw-r--r--net/ipv4/udp_bpf.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
new file mode 100644
index 000000000000..eddd973e6575
--- /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/skmsg.h>
+#include <net/sock.h>
+#include <net/udp.h>
+
+enum {
+ UDP_BPF_IPV4,
+ UDP_BPF_IPV6,
+ UDP_BPF_NUM_PROTS,
+};
+
+static struct proto *udpv6_prot_saved __read_mostly;
+static DEFINE_SPINLOCK(udpv6_prot_lock);
+static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
+
+static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
+{
+ *prot = *base;
+ prot->unhash = sock_map_unhash;
+ prot->close = sock_map_close;
+}
+
+static void udp_bpf_check_v6_needs_rebuild(struct sock *sk, struct proto *ops)
+{
+ if (sk->sk_family == AF_INET6 &&
+ unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
+ spin_lock_bh(&udpv6_prot_lock);
+ if (likely(ops != udpv6_prot_saved)) {
+ udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
+ smp_store_release(&udpv6_prot_saved, ops);
+ }
+ spin_unlock_bh(&udpv6_prot_lock);
+ }
+}
+
+static int __init udp_bpf_v4_build_proto(void)
+{
+ udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
+ return 0;
+}
+core_initcall(udp_bpf_v4_build_proto);
+
+struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
+{
+ int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
+
+ if (!psock->sk_proto)
+ udp_bpf_check_v6_needs_rebuild(sk, READ_ONCE(sk->sk_prot));
+
+ return &udp_bpf_prots[family];
+}