net: dhcpv4_server: Improve address pool range validation (a147ac9a) · Commits · Wenxi XU / zephyr

Not only check if the address pool belongs to the same subnet as the server, but also that it does not overlap with the server address - otherwise the server might end up assigning its own address. Signed-off-by:

Robert Lubos <robert.lubos@nordicsemi.no>

subsys/net/lib/dhcpv4/dhcpv4_server.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1224,6 +1224,13 @@ int net_dhcpv4_server_start(struct net_if iface, struct in_addr base_addr)
		return -EINVAL;
		}

		if ((htonl(server_addr->s_addr) >= htonl(base_addr->s_addr)) &&
		(htonl(server_addr->s_addr) <
		htonl(base_addr->s_addr) + CONFIG_NET_DHCPV4_SERVER_ADDR_COUNT)) {
		LOG_ERR("Address pool overlaps with server address.");
		return -EINVAL;
		}

		netmask = net_if_ipv4_get_netmask(iface);
		if (net_ipv4_is_addr_unspecified(&netmask)) {
		LOG_ERR("Failed to obtain subnet mask.");

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