From: Juraj Marcin <jmar...@redhat.com>
Commit aec21d3175 (qapi: Add InetSocketAddress member keep-alive)
introduces the keep-alive flag, which enables the SO_KEEPALIVE socket
option, but only on client-side sockets. However, this option is also
useful for server-side sockets, so they can check if a client is still
reachable or drop the connection otherwise.
This patch enables the SO_KEEPALIVE socket option on passive server-side
sockets if the keep-alive flag is enabled. This socket option is then
inherited by active server-side sockets communicating with connected
clients.
This patch also fixes an issue in 'qio_dns_resolver_lookup_sync_inet()'
where the keep-alive flag is not copied together with other attributes.
Signed-off-by: Juraj Marcin <jmar...@redhat.com>
---
io/dns-resolver.c | 2 ++
qapi/sockets.json | 4 ++--
util/qemu-sockets.c | 52 +++++++++++++++++++++++++--------------------
3 files changed, 33 insertions(+), 25 deletions(-)
diff --git a/io/dns-resolver.c b/io/dns-resolver.c
index 53b0e8407a..ee7403b65b 100644
--- a/io/dns-resolver.c
+++ b/io/dns-resolver.c
@@ -126,6 +126,8 @@ static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver
*resolver,
.has_mptcp = iaddr->has_mptcp,
.mptcp = iaddr->mptcp,
#endif
+ .has_keep_alive = iaddr->has_keep_alive,
+ .keep_alive = iaddr->keep_alive,
};
(*addrs)[i] = newaddr;
diff --git a/qapi/sockets.json b/qapi/sockets.json
index 6a95023315..eb50f64e3a 100644
--- a/qapi/sockets.json
+++ b/qapi/sockets.json
@@ -56,8 +56,8 @@
# @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 passive sockets. (Since 4.2)
+# @keep-alive: enable keep-alive when connecting to/listening on this socket.
+# (Since 4.2, not supported for listening sockets until 10.0)
#
# @mptcp: enable multi-path TCP. (Since 6.1)
#
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index 77477c1cd5..99357a4435 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -205,6 +205,22 @@ static int try_bind(int socket, InetSocketAddress *saddr,
struct addrinfo *e)
#endif
}
+static int inet_set_sockopts(int sock, InetSocketAddress *saddr, Error **errp)
+{
+ if (saddr->keep_alive) {
+ int keep_alive = 1;
+ int ret = setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
+ &keep_alive, sizeof(keep_alive));
+
+ if (ret < 0) {
+ error_setg_errno(errp, errno,
+ "Unable to set keep-alive option on socket");
+ return -1;
+ }
+ }
+ return 0;
+}
+
static int inet_listen_saddr(InetSocketAddress *saddr,
int port_offset,
int num,
@@ -220,12 +236,6 @@ static int inet_listen_saddr(InetSocketAddress *saddr,
int saved_errno = 0;
bool socket_created = false;
- if (saddr->keep_alive) {
- error_setg(errp, "keep-alive option is not supported for passive "
- "sockets");
- return -1;
- }
-
memset(&ai,0, sizeof(ai));
ai.ai_flags = AI_PASSIVE;
if (saddr->has_numeric && saddr->numeric) {
@@ -313,13 +323,18 @@ static int inet_listen_saddr(InetSocketAddress *saddr,
goto listen_failed;
}
} else {
- if (!listen(slisten, num)) {
+ if (listen(slisten, num)) {
+ if (errno != EADDRINUSE) {
+ error_setg_errno(errp, errno,
+ "Failed to listen on socket");
+ goto listen_failed;
+ }
+ } else {
+ if (inet_set_sockopts(slisten, saddr, errp)) {
+ goto listen_failed;
+ }
goto listen_ok;
}
- if (errno != EADDRINUSE) {
- error_setg_errno(errp, errno, "Failed to listen on
socket");
- goto listen_failed;
- }
}
/* Someone else managed to bind to the same port and beat us
* to listen on it! Socket semantics does not allow us to
@@ -474,19 +489,10 @@ int inet_connect_saddr(InetSocketAddress *saddr, Error
**errp)
error_propagate(errp, local_err);
return sock;
}
-
- if (saddr->keep_alive) {
- int val = 1;
- int ret = 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;
- }
+ if (inet_set_sockopts(sock, saddr, errp)) {
+ close(sock);
+ return -1;
}
-
return sock;
}
--
2.48.1
