| Message ID | 1618456752-139032-1-git-send-email-liyonglong@chinatelecom.cn |
|---|---|
| State | Superseded, archived |
| Commit | e7fc5d2f8302e216da05374f74a6e99b9a566669 |
| Delegated to: | Paolo Abeni |
| Headers | show |
| Series | [v2,1/2] mptcp: add MSG_PEEK support | expand |
On Thu, 2021-04-15 at 11:19 +0800, Yonglong Li wrote: > This patch adds support for MSG_PEEK flag. Packets are not removed > from the receive_queue if MSG_PEEK set in recv() system call. > > Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> > --- > net/mptcp/protocol.c | 28 ++++++++++++++++------------ > 1 file changed, 16 insertions(+), 12 deletions(-) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 0437fe4..521e67b 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -1739,12 +1739,12 @@ static void mptcp_wait_data(struct sock *sk, long *timeo) > > static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, > struct msghdr *msg, > - size_t len) > + size_t len, int flags) > { > - struct sk_buff *skb; > + struct sk_buff *skb, *tmp; > int copied = 0; > > - while ((skb = skb_peek(&msk->receive_queue)) != NULL) { > + skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { > u32 offset = MPTCP_SKB_CB(skb)->offset; > u32 data_len = skb->len - offset; > u32 count = min_t(size_t, len - copied, data_len); > @@ -1760,15 +1760,18 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, > copied += count; > > if (count < data_len) { > - MPTCP_SKB_CB(skb)->offset += count; > + if (!(flags & MSG_PEEK)) > + MPTCP_SKB_CB(skb)->offset += count; > break; > } > > - /* we will bulk release the skb memory later */ > - skb->destructor = NULL; > - msk->rmem_released += skb->truesize; > - __skb_unlink(skb, &msk->receive_queue); > - __kfree_skb(skb); > + if (!(flags & MSG_PEEK)) { > + /* we will bulk release the skb memory later */ > + skb->destructor = NULL; > + msk->rmem_released += skb->truesize; > + __skb_unlink(skb, &msk->receive_queue); > + __kfree_skb(skb); > + } > > if (copied >= len) > break; > @@ -1945,7 +1948,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > int target; > long timeo; > > - if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) > + if (flags & ~(MSG_PEEK | MSG_WAITALL | MSG_DONTWAIT)) > return -EOPNOTSUPP; Ooops... the existing code (prior to your patch) is pure nonsense here. Is probably better just drop this check entirely. Thanks! Paolo
On 2021/4/15 19:54, Paolo Abeni wrote: > On Thu, 2021-04-15 at 11:19 +0800, Yonglong Li wrote: >> This patch adds support for MSG_PEEK flag. Packets are not removed >> from the receive_queue if MSG_PEEK set in recv() system call. >> >> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> >> --- >> net/mptcp/protocol.c | 28 ++++++++++++++++------------ >> 1 file changed, 16 insertions(+), 12 deletions(-) >> >> diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c >> index 0437fe4..521e67b 100644 >> --- a/net/mptcp/protocol.c >> +++ b/net/mptcp/protocol.c >> @@ -1739,12 +1739,12 @@ static void mptcp_wait_data(struct sock *sk, long *timeo) >> >> static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, >> struct msghdr *msg, >> - size_t len) >> + size_t len, int flags) >> { >> - struct sk_buff *skb; >> + struct sk_buff *skb, *tmp; >> int copied = 0; >> >> - while ((skb = skb_peek(&msk->receive_queue)) != NULL) { >> + skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { >> u32 offset = MPTCP_SKB_CB(skb)->offset; >> u32 data_len = skb->len - offset; >> u32 count = min_t(size_t, len - copied, data_len); >> @@ -1760,15 +1760,18 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, >> copied += count; >> >> if (count < data_len) { >> - MPTCP_SKB_CB(skb)->offset += count; >> + if (!(flags & MSG_PEEK)) >> + MPTCP_SKB_CB(skb)->offset += count; >> break; >> } >> >> - /* we will bulk release the skb memory later */ >> - skb->destructor = NULL; >> - msk->rmem_released += skb->truesize; >> - __skb_unlink(skb, &msk->receive_queue); >> - __kfree_skb(skb); >> + if (!(flags & MSG_PEEK)) { >> + /* we will bulk release the skb memory later */ >> + skb->destructor = NULL; >> + msk->rmem_released += skb->truesize; >> + __skb_unlink(skb, &msk->receive_queue); >> + __kfree_skb(skb); >> + } >> >> if (copied >= len) >> break; >> @@ -1945,7 +1948,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, >> int target; >> long timeo; >> >> - if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) >> + if (flags & ~(MSG_PEEK | MSG_WAITALL | MSG_DONTWAIT)) >> return -EOPNOTSUPP; > > Ooops... the existing code (prior to your patch) is pure nonsense here. > > Is probably better just drop this check entirely. > ok, I will drop this check entirely in next patch.
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 0437fe4..521e67b 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1739,12 +1739,12 @@ static void mptcp_wait_data(struct sock *sk, long *timeo) static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, struct msghdr *msg, - size_t len) + size_t len, int flags) { - struct sk_buff *skb; + struct sk_buff *skb, *tmp; int copied = 0; - while ((skb = skb_peek(&msk->receive_queue)) != NULL) { + skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { u32 offset = MPTCP_SKB_CB(skb)->offset; u32 data_len = skb->len - offset; u32 count = min_t(size_t, len - copied, data_len); @@ -1760,15 +1760,18 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, copied += count; if (count < data_len) { - MPTCP_SKB_CB(skb)->offset += count; + if (!(flags & MSG_PEEK)) + MPTCP_SKB_CB(skb)->offset += count; break; } - /* we will bulk release the skb memory later */ - skb->destructor = NULL; - msk->rmem_released += skb->truesize; - __skb_unlink(skb, &msk->receive_queue); - __kfree_skb(skb); + if (!(flags & MSG_PEEK)) { + /* we will bulk release the skb memory later */ + skb->destructor = NULL; + msk->rmem_released += skb->truesize; + __skb_unlink(skb, &msk->receive_queue); + __kfree_skb(skb); + } if (copied >= len) break; @@ -1945,7 +1948,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int target; long timeo; - if (msg->msg_flags & ~(MSG_WAITALL | MSG_DONTWAIT)) + if (flags & ~(MSG_PEEK | MSG_WAITALL | MSG_DONTWAIT)) return -EOPNOTSUPP; mptcp_lock_sock(sk, __mptcp_splice_receive_queue(sk)); @@ -1962,7 +1965,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, while (copied < len) { int bytes_read; - bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied); + bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags); if (unlikely(bytes_read < 0)) { if (!copied) copied = bytes_read; @@ -2046,7 +2049,8 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, pr_debug("msk=%p data_ready=%d rx queue empty=%d copied=%d", msk, test_bit(MPTCP_DATA_READY, &msk->flags), skb_queue_empty_lockless(&sk->sk_receive_queue), copied); - mptcp_rcv_space_adjust(msk, copied); + if (!(flags & MSG_PEEK)) + mptcp_rcv_space_adjust(msk, copied); release_sock(sk); return copied;
This patch adds support for MSG_PEEK flag. Packets are not removed from the receive_queue if MSG_PEEK set in recv() system call. Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn> --- net/mptcp/protocol.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)