[RFC PATCH v2 11/48] tcp_bpf: Inline do_tcp_sendpages as it's now a wrapper around tcp_sendmsg

David Howells
2023-03-29T14:17:37Z

do_tcp_sendpages() is now just a small wrapper around tcp_sendmsg_locked(),
so inline it. This is part of replacing ->sendpage() with a call to
sendmsg() with MSG_SPLICE_PAGES set.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: John Fastabend <john.fastabend@gmail.com>
cc: Jakub Sitnicki <jakub@cloudflare.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: netdev@vger.kernel.org
cc: bpf@vger.kernel.org
---
net/ipv4/tcp_bpf.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index cf26d65ca389..7f17134637eb 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -72,11 +72,13 @@ static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
{
bool apply = apply_bytes;
struct scatterlist *sge;
+ struct msghdr msghdr = { .msg_flags = flags | MSG_SPLICE_PAGES, };
struct page *page;
int size, ret = 0;
u32 off;

while (1) {
+ struct bio_vec bvec;
bool has_tx_ulp;

sge = sk_msg_elem(msg, msg->sg.start);
@@ -88,16 +90,18 @@ static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
tcp_rate_check_app_limited(sk);
retry:
has_tx_ulp = tls_sw_has_ctx_tx(sk);
- if (has_tx_ulp) {
- flags |= MSG_SENDPAGE_NOPOLICY;
- ret = kernel_sendpage_locked(sk,
- page, off, size, flags);
- } else {
- ret = do_tcp_sendpages(sk, page, off, size, flags);
- }
+ if (has_tx_ulp)
+ msghdr.msg_flags |= MSG_SENDPAGE_NOPOLICY;

+ if (flags & MSG_SENDPAGE_NOTLAST)
+ msghdr.msg_flags |= MSG_MORE;
+
+ bvec_set_page(&bvec, page, size, off);
+ iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size);
+ ret = tcp_sendmsg_locked(sk, &msghdr, size);
if (ret <= 0)
return ret;
+
if (apply)
apply_bytes -= ret;
msg->sg.size -= ret;
@@ -398,7 +402,7 @@ static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
long timeo;
int flags;

- /* Don't let internal do_tcp_sendpages() flags through */
+ /* Don't let internal sendpage flags through */
flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED);
flags |= MSG_NO_SHARED_FRAGS;