From: Cong Wang <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jakub Sitnicki <[email protected]>
Cc: Lorenz Bauer <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
---
include/net/udp.h | 2 ++
net/ipv4/af_inet.c | 1 +
net/ipv4/udp.c | 34 ++++++++++++++++++++++++++++++++++
3 files changed, 37 insertions(+)
diff --git a/include/net/udp.h b/include/net/udp.h
index 5264ba1439f9..44a94cfc63b5 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -330,6 +330,8 @@ struct sock *__udp6_lib_lookup(struct net *net,
struct sk_buff *skb);
struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport);
+int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
+ sk_read_actor_t recv_actor);
/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
* possibly multiple cache miss on dequeue()
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index d8c73a848c53..df8e8e238756 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1072,6 +1072,7 @@ const struct proto_ops inet_dgram_ops = {
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.sendmsg_locked = udp_sendmsg_locked,
+ .read_sock = udp_read_sock,
.recvmsg = inet_recvmsg,
.mmap = sock_no_mmap,
.sendpage = inet_sendpage,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 93db853601d7..54f24b1d4f65 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1798,6 +1798,40 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned
int flags,
}
EXPORT_SYMBOL(__skb_recv_udp);
+int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
+ sk_read_actor_t recv_actor)
+{
+ int copied = 0;
+
+ while (1) {
+ int offset = 0, err;
+ struct sk_buff *skb;
+
+ skb = __skb_recv_udp(sk, 0, 1, &offset, &err);
+ if (!skb)
+ break;
+ if (offset < skb->len) {
+ int used;
+ size_t len;
+
+ len = skb->len - offset;
+ used = recv_actor(desc, skb, offset, len);
+ if (used <= 0) {
+ if (!copied)
+ copied = used;
+ break;
+ } else if (used <= len) {
+ copied += used;
+ offset += used;
+ }
+ }
+ if (!desc->count)
+ break;
+ }
+
+ return copied;
+}
+
/*
* This should be easy, if there is something there we
* return it, otherwise we block.
--
2.25.1
