dhcpv4: DHCP pool size is off-by-one

[project/odhcpd.git] / src / dhcpv4.c

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 370e1b94e805666b2074b044bec9b02b7dab37e1..679b7931d2e35e0ceb35c3ece50f1f05ed59dc79 100644 (file)
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -263,18 +263,21 @@ static int setup_dhcpv4_addresses(struct interface *iface)
        end = start = iface->dhcpv4_local.s_addr & iface->dhcpv4_mask.s_addr;
 
        /* Auto allocate ranges */
-       if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffff00) {
+       if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffff00) {           /* /24, 150 of 256, [100..249] */
                iface->dhcpv4_start_ip.s_addr = start | htonl(100);
-               iface->dhcpv4_end_ip.s_addr = end | htonl(250);
-       } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffc0) {
+               iface->dhcpv4_end_ip.s_addr = end | htonl(100 + 150 - 1);
+       } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffff80) {    /* /25, 100 of 128, [20..119] */
+               iface->dhcpv4_start_ip.s_addr = start | htonl(20);
+               iface->dhcpv4_end_ip.s_addr = end | htonl(20 + 100 - 1);
+       } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffc0) {    /* /26, 50 of 64, [10..59] */
                iface->dhcpv4_start_ip.s_addr = start | htonl(10);
-               iface->dhcpv4_end_ip.s_addr = end | htonl(60);
-       } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffe0) {
+               iface->dhcpv4_end_ip.s_addr = end | htonl(10 + 50 - 1);
+       } else if (ntohl(iface->dhcpv4_mask.s_addr) <= 0xffffffe0) {    /* /27, 20 of 32, [10..29] */
                iface->dhcpv4_start_ip.s_addr = start | htonl(10);
-               iface->dhcpv4_end_ip.s_addr = end | htonl(30);
-       } else {
+               iface->dhcpv4_end_ip.s_addr = end | htonl(10 + 20 - 1);
+       } else {                                                        /* /28, 10 of 16, [3..12] */
                iface->dhcpv4_start_ip.s_addr = start | htonl(3);
-               iface->dhcpv4_end_ip.s_addr = end | htonl(12);
+               iface->dhcpv4_end_ip.s_addr = end | htonl(3 + 10 - 1);
        }
 
        return 0;