I apologize for dragging my feet on this review.
Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> writes:
> It's needed to provide keepalive for nbd client to track server
> availability.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> ---
>
> v3: [by Markus's comments]
>
> - Fix commit subject
> - Add comment to qapi and restrict server-side connections
> - Fix s/"keep-alive="/",keep-alive"/
>
>
> qapi/sockets.json | 6 +++++-
> util/qemu-sockets.c | 28 ++++++++++++++++++++++++++++
> 2 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/qapi/sockets.json b/qapi/sockets.json
> index fc81d8d5e8..c44af481a1 100644
> --- a/qapi/sockets.json
> +++ b/qapi/sockets.json
> @@ -53,6 +53,9 @@
> #
> # @ipv6: whether to accept IPv6 addresses, default try both IPv4 and IPv6
> #
> +# @keep-alive: enable keep-alive when connecting to this socket. Not
> supported
> +# for server-side connections. (Since 4.1)
> +#
Is "server-side connection" is an established term?
For what it's worth, "passive socket" is, see listen(2).
> # Since: 1.3
> ##
> { 'struct': 'InetSocketAddress',
> @@ -61,7 +64,8 @@
> '*numeric': 'bool',
> '*to': 'uint16',
> '*ipv4': 'bool',
> - '*ipv6': 'bool' } }
> + '*ipv6': 'bool',
> + '*keep-alive': 'bool' } }
>
> ##
> # @UnixSocketAddress:
> diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> index 8850a280a8..813063761b 100644
> --- a/util/qemu-sockets.c
> +++ b/util/qemu-sockets.c
> @@ -438,6 +438,12 @@ int inet_connect_saddr(InetSocketAddress *saddr, Error
> **errp)
> struct addrinfo *res, *e;
> int sock = -1;
>
> + if (saddr->keep_alive) {
> + error_setg(errp, "keep-alive options is not supported for
> server-side "
> + "connection");
> + return -1;
> + }
> +
> res = inet_parse_connect_saddr(saddr, errp);
> if (!res) {
> return -1;
I'm afraid you added this to the wrong function; ...
> @@ -457,6 +463,19 @@ int inet_connect_saddr(InetSocketAddress *saddr, Error
> **errp)
> }
>
> freeaddrinfo(res);
> +
> + if (saddr->keep_alive) {
... it renders this code unreachable.
I guess the "not supported for passive sockets" check should go into
inet_listen_saddr() instead.
> + int val = 1;
> + int ret = qemu_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
> + &val, sizeof(val));
> +
> + if (ret < 0) {
> + error_setg_errno(errp, errno, "Unable to set KEEPALIVE");
> + close(sock);
> + return -1;
> + }
> + }
> +
> return sock;
> }
>
> @@ -652,6 +671,15 @@ int inet_parse(InetSocketAddress *addr, const char *str,
> Error **errp)
> }
> addr->has_ipv6 = true;
> }
> + begin = strstr(optstr, ",keep-alive");
> + if (begin) {
> + if (inet_parse_flag("keep-alive", begin + strlen(",keep-alive"),
> + &addr->keep_alive, errp) < 0)
> + {
> + return -1;
> + }
> + addr->has_keep_alive = true;
> + }
> return 0;
> }
