SymbX/systemd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dhcp-server-request: check server address in DHCPDECLINE and DHCPRELEASE

Browse Source 
Otherwise, we may do something wrong by messages for another DHCP server.
Let's silently ignore messages with unmatching server identifier.

Also, logs something when we receive DHCPRELEASE but found lease does
not match the reported address.
This commit is contained in:
Yu Watanabe
2026-05-22 04:30:34 +09:00
parent e359c6df65
commit d40d021ca5
1 changed files with 9 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libsystemd-network/dhcp-server-request.c
+9 -6
View File
@@ -364,10 +364,12 @@ static int dhcp_server_process_decline(sd_dhcp_server *server, DHCPRequest *req,
assert(server);
assert(req);
if (req->server_address != server->address)
return 0; /* The message is not for us. Let's silently ignore the packet. */
/* TODO: make sure we don't offer this address again for a while. */
log_dhcp_server(server, "DECLINE (0x%x): %s", be32toh(req->message->xid), strna(error_message));
/* TODO: make sure we don't offer this address again */
return 0;
}
@@ -375,19 +377,20 @@ static int dhcp_server_process_release(sd_dhcp_server *server, DHCPRequest *req)
assert(server);
assert(req);
log_dhcp_server(server, "RELEASE (0x%x)",
be32toh(req->message->xid));
if (req->server_address != server->address)
return 0; /* The message is not for us. Let's silently ignore the packet. */
sd_dhcp_server_lease *existing_lease = hashmap_get(server->bound_leases_by_client_id, &req->client_id);
if (!existing_lease)
return 0;
if (existing_lease->address != req->message->ciaddr)
return 0;
return -EBADMSG;
sd_dhcp_server_lease_unref(existing_lease);
dhcp_server_on_lease_change(server);
log_dhcp_server(server, "RELEASE (0x%x)", be32toh(req->message->xid));
return 0;
}