dilim/systemd
1
0 Fork 0
mirror of https://github.com/systemd/systemd.git synced 2026-11-06 05:17:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

networkd: reject special addresses in static leases

Browse Source 
Static DHCP leases currently accept the subnet and broadcast addresses
when they match a client, causing unusable addresses to be offered.

Reject both boundary addresses before a static lease is selected while
retaining support for valid addresses outside the dynamic pool.

(cherry picked from commit 7af06990f1)
(cherry picked from commit 29b529d672)
This commit is contained in:
zouge666 authored and Luca Boccassi committed 2026-11-05 14:48:10 +00:00
1 parent b79761ddc3
commit 827c47be09
2 files changed
+57
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

src/libsystemd-network/sd-dhcp-server-lease.c
+5
View File
@@ -174,6 +174,11 @@ sd_dhcp_server_lease* dhcp_server_get_static_lease(sd_dhcp_server *server, const
if ((static_lease->address & server->netmask) != server->subnet)
return NULL;
/* Check if the address is neither the subnet nor the broadcast address. */
if (static_lease->address == server->subnet ||
static_lease->address == (server->subnet | ~server->netmask))
return NULL;
/* Check if the address is different from the server address. */
if (static_lease->address == server->address)
return NULL;
src/libsystemd-network/test-dhcp-server.c
+52
View File
@@ -489,6 +489,58 @@ TEST(dhcp_server_static_lease_client_id_change) {
check_bound_lease(server, static_address, &client_id_mac);
}
TEST(dhcp_server_static_lease_special_addresses) {
_cleanup_(sd_dhcp_server_unrefp) sd_dhcp_server *server = NULL;
ASSERT_OK(sd_dhcp_server_new(&server, 4242));
ASSERT_OK(sd_dhcp_server_configure_pool(server, &(struct in_addr) { htobe32(INADDR_LOOPBACK) },
8, 0, 0));
sd_dhcp_client_id client_id_subnet = {
.size = 7,
.id.type = 1,
.id.eth.haddr = { 'A', 'B', 'C', 'D', 'E', 'G' },
};
sd_dhcp_client_id client_id_broadcast = {
.size = 7,
.id.type = 1,
.id.eth.haddr = { 'A', 'B', 'C', 'D', 'E', 'H' },
};
sd_dhcp_client_id client_id_normal = {
.size = 7,
.id.type = 1,
.id.eth.haddr = { 'A', 'B', 'C', 'D', 'E', 'I' },
};
ASSERT_OK(sd_dhcp_server_set_static_lease(
server,
&(struct in_addr) { .s_addr = server->subnet },
client_id_subnet.raw,
client_id_subnet.size,
/* hostname= */ NULL));
ASSERT_OK(sd_dhcp_server_set_static_lease(
server,
&(struct in_addr) { .s_addr = server->subnet | ~server->netmask },
client_id_broadcast.raw,
client_id_broadcast.size,
/* hostname= */ NULL));
ASSERT_OK(sd_dhcp_server_set_static_lease(
server,
&(struct in_addr) { .s_addr = htobe32(INADDR_LOOPBACK + 42) },
client_id_normal.raw,
client_id_normal.size,
/* hostname= */ NULL));
/* Static lease lookup is used while processing DHCPDISCOVER. */
DHCPRequest req = { .client_id = client_id_subnet };
ASSERT_NULL(dhcp_server_get_static_lease(server, &req));
req.client_id = client_id_broadcast;
ASSERT_NULL(dhcp_server_get_static_lease(server, &req));
req.client_id = client_id_normal;
ASSERT_NOT_NULL(dhcp_server_get_static_lease(server, &req));
}
TEST(sd_dhcp_server_set_static_lease) {
_cleanup_(sd_dhcp_server_unrefp) sd_dhcp_server *server = NULL;
ASSERT_OK(sd_dhcp_server_new(&server, 4242));