[PATCH RFC net-next 1/6] sock: MSG_PEEK support for sk_error_queue
From: Sowmini Varadhan <hidden>
Date: 2018-01-17 12:37:22
Subsystem:
networking drivers, networking [general], networking [sockets], packet sockets, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Willem de Bruijn, Linus Torvalds, Jason Wang
Allow the application the ability to use MSG_PEEK with sk_error_queue so that it can peek and re-read message in cases where MSG_TRUNC may be encountered. Signed-off-by: Sowmini Varadhan <redacted> --- drivers/net/tun.c | 2 +- include/net/sock.h | 2 +- net/core/sock.c | 7 +++++-- net/packet/af_packet.c | 3 ++- 4 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2fba3be..cfd0e0f 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c@@ -2313,7 +2313,7 @@ static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len, } if (flags & MSG_ERRQUEUE) { ret = sock_recv_errqueue(sock->sk, m, total_len, - SOL_PACKET, TUN_TX_TIMESTAMP); + SOL_PACKET, TUN_TX_TIMESTAMP, flags); goto out; } ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
diff --git a/include/net/sock.h b/include/net/sock.h
index 73b7830..f0b6990 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -2343,7 +2343,7 @@ static inline bool sk_listener(const struct sock *sk) int sock_get_timestamp(struct sock *, struct timeval __user *); int sock_get_timestampns(struct sock *, struct timespec __user *); int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level, - int type); + int type, int flags); bool sk_ns_capable(const struct sock *sk, struct user_namespace *user_ns, int cap);
diff --git a/net/core/sock.c b/net/core/sock.c
index 72d14b2..4f52677 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c@@ -2887,7 +2887,7 @@ void sock_enable_timestamp(struct sock *sk, int flag) } int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, - int level, int type) + int level, int type, int flags) { struct sock_exterr_skb *serr; struct sk_buff *skb;
@@ -2916,7 +2916,10 @@ int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, err = copied; out_free_skb: - kfree_skb(skb); + if (likely(!(flags & MSG_PEEK))) + kfree_skb(skb); + else + skb_queue_head(&sk->sk_error_queue, skb); out: return err; }
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index ee7aa0b..4314f31 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c@@ -3294,7 +3294,8 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, if (flags & MSG_ERRQUEUE) { err = sock_recv_errqueue(sk, msg, len, - SOL_PACKET, PACKET_TX_TIMESTAMP); + SOL_PACKET, PACKET_TX_TIMESTAMP, + flags); goto out; }
--
1.7.1