[PATCH] dhcp-transport: Do not leak fds during bind

[PATCH] dhcp-transport: Do not leak fds during bind

[Denis Kenzior]

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When a lease is renewed, the transport bind operation is called.  This
can be done multiple times by dhcp_client, whenever a lease has been
obtained or renewed.  This can result in fds being leaked.

If bind operation has previously succeeded, simply return and reuse the
already created fd.
---
 ell/dhcp-transport.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ell/dhcp-transport.c b/ell/dhcp-transport.c
index 52da2db04f49..b466f136972c 100644
--- a/ell/dhcp-transport.c
+++ b/ell/dhcp-transport.c
@@ -361,6 +361,9 @@ static int _dhcp_default_transport_bind(struct dhcp_transport *s,
 	if (!transport->io)
 		return -EIO;
 
+	if (transport->udp_fd >= 0)
+		return 0;
+
 	fd = kernel_udp_socket_open(transport->ifname, saddr, transport->port);
 	if (fd < 0)
 		return fd;
@@ -552,6 +555,7 @@ struct dhcp_transport *_dhcp_default_transport_new(uint32_t ifindex,
 	transport->super.ifindex = ifindex;
 	l_strlcpy(transport->ifname, ifname, IFNAMSIZ);
 	transport->port = port;
+	transport->udp_fd = -1;
 
 	return &transport->super;
 }
-- 
2.32.0

Re: [PATCH] dhcp-transport: Do not leak fds during bind

[Denis Kenzior]

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On 5/16/22 14:55, Denis Kenzior wrote:
> When a lease is renewed, the transport bind operation is called.  This
> can be done multiple times by dhcp_client, whenever a lease has been
> obtained or renewed.  This can result in fds being leaked.
> 
> If bind operation has previously succeeded, simply return and reuse the
> already created fd.
> ---
>   ell/dhcp-transport.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 

Applied.