[PATCH v3 42/55] tcp_bpf: Make tcp_bpf_sendpage() go through tcp_bpf_sendmsg(MSG_SPLICE_PAGES)

David Howells
2023-03-31T16:31:16Z

Translate tcp_bpf_sendpage() calls to tcp_bpf_sendmsg(MSG_SPLICE_PAGES).

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: bpf@vger.kernel.org
cc: netdev@vger.kernel.org
---
net/ipv4/tcp_bpf.c | 49 +++++++++-------------------------------------
1 file changed, 9 insertions(+), 40 deletions(-)

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 7f17134637eb..de37a4372437 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -485,49 +485,18 @@ static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset,
size_t size, int flags)
{
- struct sk_msg tmp, *msg = NULL;
- int err = 0, copied = 0;
- struct sk_psock *psock;
- bool enospc = false;
-
- psock = sk_psock_get(sk);
- if (unlikely(!psock))
- return tcp_sendpage(sk, page, offset, size, flags);
+ struct bio_vec bvec;
+ struct msghdr msg = {
+ .msg_flags = flags | MSG_SPLICE_PAGES,
+ };

- lock_sock(sk);
- if (psock->cork) {
- msg = psock->cork;
- } else {
- msg = &tmp;
- sk_msg_init(msg);
- }
+ bvec_set_page(&bvec, page, size, offset);
+ iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size);

- /* Catch case where ring is full and sendpage is stalled. */
- if (unlikely(sk_msg_full(msg)))
- goto out_err;
-
- sk_msg_page_add(msg, page, size, offset);
- sk_mem_charge(sk, size);
- copied = size;
- if (sk_msg_full(msg))
- enospc = true;
- if (psock->cork_bytes) {
- if (size > psock->cork_bytes)
- psock->cork_bytes = 0;
- else
- psock->cork_bytes -= size;
- if (psock->cork_bytes && !enospc)
- goto out_err;
- /* All cork bytes are accounted, rerun the prog. */
- psock->eval = __SK_NONE;
- psock->cork_bytes = 0;
- }
+ if (flags & MSG_SENDPAGE_NOTLAST)
+ msg.msg_flags |= MSG_MORE;

- err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags);
-out_err:
- release_sock(sk);
- sk_psock_put(sk, psock);
- return copied ? copied : err;
+ return tcp_bpf_sendmsg(sk, &msg, size);
}

enum {