Re: [PATCH 6/8] udp: Unify udp_sock_handler_splice() with udp_sock_handler()

On Tue, Dec 13, 2022 at 11:48:58PM +0100, Stefano Brivio wrote:

On Mon, 5 Dec 2022 19:14:23 +1100 David Gibson wrote:

...

These two functions now have a very similar structure, and their first part (calling recvmmsg()) is functionally identical. So, merge the two functions into one.

Signed-off-by: David Gibson --- udp.c | 86 +++++++++++++++++++---------------------------------------- 1 file changed, 28 insertions(+), 58 deletions(-)

diff --git a/udp.c b/udp.c index 7c601cc..6ccfe8c 100644 --- a/udp.c +++ b/udp.c @@ -590,52 +590,6 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n, sendmmsg(s, mmh_send + start, n, MSG_NOSIGNAL); }

-/** - * udp_sock_handler_splice() - Handler for socket mapped to "spliced" connection - * @c: Execution context - * @ref: epoll reference - * @events: epoll events bitmap - * @now: Current timestamp - */ -static void udp_sock_handler_splice(const struct ctx *c, union epoll_ref ref, - uint32_t events, const struct timespec *now) -{ - in_port_t dst = ref.r.p.udp.udp.port; - int v6 = ref.r.p.udp.udp.v6, n, i, m; - struct mmsghdr *mmh_recv; - - if (!(events & EPOLLIN)) - return; - - if (v6) - mmh_recv = udp6_l2_mh_sock; - else - mmh_recv = udp4_l2_mh_sock; - - n = recvmmsg(ref.r.s, mmh_recv, UDP_MAX_FRAMES, 0, NULL); - - if (n <= 0) - return; - - if (v6) - udp_localname6.sin6_port = htons(dst); - else - udp_localname4.sin_port = htons(dst); - - for (i = 0; i < n; i += m) { - in_port_t src = sa_port(v6, mmh_recv[i].msg_hdr.msg_name); - - for (m = 1; i + m < n; m++) { - void *mname = mmh_recv[i + m].msg_hdr.msg_name; - if (sa_port(v6, mname) != src) - break; - } - - udp_splice_sendfrom(c, i, m, src, dst, v6, ref.r.p.udp.udp.ns, - ref.r.p.udp.udp.orig, now); - } -} - /** * udp_update_hdr4() - Update headers for one IPv4 datagram * @c: Execution context @@ -945,27 +899,43 @@ void udp_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t events, { in_port_t dstport = ref.r.p.udp.udp.port; bool v6 = ref.r.p.udp.udp.v6; - struct mmsghdr *sock_mmh; + struct mmsghdr *mmh_recv; + unsigned int i, m; ssize_t n;

- if (events == EPOLLERR) + if (!(events & EPOLLIN))

Pre-existing, unrelated issue, but this reminds me: we don't handle socket errors here, and while udp_timer_one() will drop any sockets we created, eventually, it would probably be better to act right away.

Ok... I'm not sure what, if anything, you would like me to do about it, however.

Not that I have in mind a valid example of an error on UDP sockets, except perhaps if the interface goes down (but we'll handle that separately).

-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson