dhcpc: Use client IP address as source address for DHCP renew/rebind messages
RFC2131 paragraph 4.1 states DHCP messages broadcast by a client prior to
that client obtaining its IP address must have the source IP address
field in the header set to 0.
Request messages transmitted in renewing and rebinding state need to use
the obtained IP address as source IP address in the header; this behavior
lines up with other implementations like ISC dhcp client.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 2fe84e1..6c2b112 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -675,10 +675,10 @@
* client reverts to using the IP broadcast address.
*/
-static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
+static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet, uint32_t src_nip)
{
return udhcp_send_raw_packet(packet,
- /*src*/ INADDR_ANY, CLIENT_PORT,
+ /*src*/ src_nip, CLIENT_PORT,
/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
client_config.ifindex);
}
@@ -689,7 +689,7 @@
return udhcp_send_kernel_packet(packet,
ciaddr, CLIENT_PORT,
server, SERVER_PORT);
- return raw_bcast_from_client_config_ifindex(packet);
+ return raw_bcast_from_client_config_ifindex(packet, ciaddr);
}
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
@@ -715,7 +715,7 @@
add_client_options(&packet);
bb_info_msg("Sending discover...");
- return raw_bcast_from_client_config_ifindex(&packet);
+ return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
}
/* Broadcast a DHCP request message */
@@ -759,7 +759,7 @@
addr.s_addr = requested;
bb_info_msg("Sending select for %s...", inet_ntoa(addr));
- return raw_bcast_from_client_config_ifindex(&packet);
+ return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
}
/* Unicast or broadcast a DHCP renew message */
@@ -827,7 +827,7 @@
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
bb_info_msg("Sending decline...");
- return raw_bcast_from_client_config_ifindex(&packet);
+ return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
}
#endif