diff options
-rw-r--r-- | src/dnsmasq/nm-dnsmasq-utils.c | 83 | ||||
-rw-r--r-- | src/dnsmasq/tests/test-dnsmasq-utils.c | 77 |
2 files changed, 101 insertions, 59 deletions
diff --git a/src/dnsmasq/nm-dnsmasq-utils.c b/src/dnsmasq/nm-dnsmasq-utils.c index e4f4324b85..cee52c3def 100644 --- a/src/dnsmasq/nm-dnsmasq-utils.c +++ b/src/dnsmasq/nm-dnsmasq-utils.c @@ -35,11 +35,12 @@ nm_dnsmasq_utils_get_range (const NMPlatformIP4Address *addr, { guint32 host = addr->address; guint8 prefix = addr->plen; - guint32 netmask = nm_utils_ip4_prefix_to_netmask (prefix); - guint32 first, last, reserved; + guint32 netmask; + guint32 first, last, mid, reserved; + const guint32 NUM = 256; - g_return_val_if_fail (out_first != NULL, FALSE); - g_return_val_if_fail (out_last != NULL, FALSE); + g_return_val_if_fail (out_first, FALSE); + g_return_val_if_fail (out_last, FALSE); if (prefix > 30) { if (out_error_desc) @@ -47,29 +48,69 @@ nm_dnsmasq_utils_get_range (const NMPlatformIP4Address *addr, return FALSE; } - /* Find the first available address *after* the local machine's IP */ - first = (host & netmask) + htonl (1); + if (prefix < 24) { + /* if the subnet is larger then /24, we partition it and treat it + * like it would be a /24. + * + * Hence, the resulting range will always be between x.x.x.1/24 + * and x.x.x.254/24, with x.x.x.0 being the network address of the + * host. + * + * In this case, only a /24 portion of the subnet is used. + * No particular reason for that, but it's unlikely that a user + * would use NetworkManager's shared method when having hundered + * of DHCP clients. So, restrict the range to the same /24 in + * which the host address lies. + */ + prefix = 24; + } + + netmask = nm_utils_ip4_prefix_to_netmask (prefix); + + /* treat addresses in host-order from here on. */ + netmask = ntohl (netmask); + host = ntohl (host); - /* Shortcut: allow a max of 253 addresses; the - htonl(1) here is to assure - * that we don't set 'last' to the broadcast address of the network. */ - if (prefix < 24) - last = (host | ~nm_utils_ip4_prefix_to_netmask (24)) - htonl (1); - else - last = (host | ~netmask) - htonl(1); + /* if host is the network or broadcast address, coerce it to + * one above or below. Usually, we wouldn't expect the user + * to pick such an address. */ + if (host == (host & netmask)) + host++; + else if (host == (host | ~netmask)) + host--; - /* Figure out which range (either above the host address or below it) - * has more addresses. Reserve some addresses for static IPs. + /* Exclude the network and broadcast address. */ + first = (host & netmask) + 1; + last = (host | ~netmask) - 1; + + /* Depending on whether host is above or below the middle of + * the subnet, the larger part if handed out. + * + * If the host is in the lower half, the range starts + * at the lower end with the host (plus reserved), until the + * broadcast address + * + * If the host is in the upper half, the range starts above + * the network-address and goes up until the host (except reserved). + * + * reserved is up to 8 addresses, 10% of the determined range. */ - if (ntohl (host) - ntohl (first) > ntohl (last) - ntohl (host)) { - /* Range below the host's IP address */ - reserved = (guint32) ((ntohl (host) - ntohl (first)) / 10); - last = host - htonl (MIN (reserved, 8)) - htonl (1); + mid = (host & netmask) | (((first + last) / 2) & ~netmask); + if (host > mid) { + /* use lower range */ + reserved = NM_MIN (((host - first) / 10), 8); + last = host - 1 - reserved; + first = NM_MAX (first, last > NUM ? last - NUM : 0); } else { - /* Range above host's IP address */ - reserved = (guint32) ((ntohl (last) - ntohl (host)) / 10); - first = host + htonl (MIN (reserved, 8)) + htonl (1); + /* use upper range */ + reserved = NM_MIN (((last - host) / 10), 8); + first = host + 1 + reserved; + last = NM_MIN (last, first < 0xFFFFFFFF - NUM ? first + NUM : 0xFFFFFFFF); } + first = htonl (first); + last = htonl (last); + nm_utils_inet4_ntop (first, out_first); nm_utils_inet4_ntop (last, out_last); diff --git a/src/dnsmasq/tests/test-dnsmasq-utils.c b/src/dnsmasq/tests/test-dnsmasq-utils.c index e62a20a016..b311ccb4a0 100644 --- a/src/dnsmasq/tests/test-dnsmasq-utils.c +++ b/src/dnsmasq/tests/test-dnsmasq-utils.c @@ -41,6 +41,7 @@ test_address_ranges (void) g_assert (!_error_desc); \ g_assert_cmpstr (_first, ==, (expected_first"")); \ g_assert_cmpstr (_last, ==, (expected_last"")); \ + g_assert_cmpint ((ntohl (nmtst_inet4_from_string (_last)) - ntohl (nmtst_inet4_from_string (_first))), <=, 244); \ } G_STMT_END #define _test_address_range_fail(addr, plen) \ @@ -58,68 +59,68 @@ test_address_ranges (void) _test_address_range_fail ("1.2.3.1", 31); - _test_address_range ("0.0.0.0", 30, "0.0.0.1", "0.0.0.247"); + _test_address_range ("0.0.0.0", 30, "0.0.0.2", "0.0.0.2"); _test_address_range ("0.0.0.1", 30, "0.0.0.2", "0.0.0.2"); _test_address_range ("0.0.0.2", 30, "0.0.0.1", "0.0.0.1"); - _test_address_range ("0.0.0.3", 30, "0.0.0.12", "0.0.0.2"); - _test_address_range ("1.2.3.0", 30, "1.2.3.1", "1.2.3.247"); + _test_address_range ("0.0.0.3", 30, "0.0.0.1", "0.0.0.1"); + _test_address_range ("1.2.3.0", 30, "1.2.3.2", "1.2.3.2"); _test_address_range ("1.2.3.1", 30, "1.2.3.2", "1.2.3.2"); _test_address_range ("1.2.3.2", 30, "1.2.3.1", "1.2.3.1"); - _test_address_range ("1.2.3.3", 30, "1.2.3.12", "1.2.3.2"); - _test_address_range ("1.2.3.4", 30, "1.2.3.5", "1.2.3.251"); + _test_address_range ("1.2.3.3", 30, "1.2.3.1", "1.2.3.1"); + _test_address_range ("1.2.3.4", 30, "1.2.3.6", "1.2.3.6"); _test_address_range ("1.2.3.5", 30, "1.2.3.6", "1.2.3.6"); _test_address_range ("1.2.3.6", 30, "1.2.3.5", "1.2.3.5"); - _test_address_range ("1.2.3.7", 30, "1.2.3.16", "1.2.3.6"); - _test_address_range ("1.2.3.8", 30, "1.2.3.9", "1.2.3.255"); + _test_address_range ("1.2.3.7", 30, "1.2.3.5", "1.2.3.5"); + _test_address_range ("1.2.3.8", 30, "1.2.3.10", "1.2.3.10"); _test_address_range ("1.2.3.9", 30, "1.2.3.10", "1.2.3.10"); - _test_address_range ("255.255.255.0", 30, "255.255.255.1", "255.255.255.247"); + _test_address_range ("255.255.255.0", 30, "255.255.255.2", "255.255.255.2"); _test_address_range ("255.255.255.1", 30, "255.255.255.2", "255.255.255.2"); _test_address_range ("255.255.255.2", 30, "255.255.255.1", "255.255.255.1"); - _test_address_range ("255.255.255.3", 30, "255.255.255.12", "255.255.255.2"); - _test_address_range ("255.255.255.248", 30, "255.255.255.249", "255.255.255.239"); + _test_address_range ("255.255.255.3", 30, "255.255.255.1", "255.255.255.1"); + _test_address_range ("255.255.255.248", 30, "255.255.255.250", "255.255.255.250"); _test_address_range ("255.255.255.249", 30, "255.255.255.250", "255.255.255.250"); _test_address_range ("255.255.255.250", 30, "255.255.255.249", "255.255.255.249"); - _test_address_range ("255.255.255.251", 30, "255.255.255.4", "255.255.255.250"); - _test_address_range ("255.255.255.252", 30, "255.255.255.253", "255.255.255.243"); + _test_address_range ("255.255.255.251", 30, "255.255.255.249", "255.255.255.249"); + _test_address_range ("255.255.255.252", 30, "255.255.255.254", "255.255.255.254"); _test_address_range ("255.255.255.253", 30, "255.255.255.254", "255.255.255.254"); _test_address_range ("255.255.255.254", 30, "255.255.255.253", "255.255.255.253"); - _test_address_range ("255.255.255.255", 30, "255.255.255.8", "255.255.255.254"); + _test_address_range ("255.255.255.255", 30, "255.255.255.253", "255.255.255.253"); - _test_address_range ("0.0.0.0", 29, "0.0.0.1", "0.0.0.247"); + _test_address_range ("0.0.0.0", 29, "0.0.0.2", "0.0.0.6"); _test_address_range ("0.0.0.1", 29, "0.0.0.2", "0.0.0.6"); _test_address_range ("0.0.0.2", 29, "0.0.0.3", "0.0.0.6"); _test_address_range ("0.0.0.3", 29, "0.0.0.4", "0.0.0.6"); _test_address_range ("0.0.0.4", 29, "0.0.0.1", "0.0.0.3"); _test_address_range ("0.0.0.5", 29, "0.0.0.1", "0.0.0.4"); _test_address_range ("0.0.0.6", 29, "0.0.0.1", "0.0.0.5"); - _test_address_range ("0.0.0.7", 29, "0.0.0.16", "0.0.0.6"); - _test_address_range ("0.0.0.8", 29, "0.0.0.9", "0.0.0.255"); + _test_address_range ("0.0.0.7", 29, "0.0.0.1", "0.0.0.5"); + _test_address_range ("0.0.0.8", 29, "0.0.0.10", "0.0.0.14"); _test_address_range ("0.0.0.9", 29, "0.0.0.10", "0.0.0.14"); - _test_address_range ("1.2.3.0", 29, "1.2.3.1", "1.2.3.247"); + _test_address_range ("1.2.3.0", 29, "1.2.3.2", "1.2.3.6"); _test_address_range ("1.2.3.1", 29, "1.2.3.2", "1.2.3.6"); _test_address_range ("1.2.3.2", 29, "1.2.3.3", "1.2.3.6"); _test_address_range ("1.2.3.3", 29, "1.2.3.4", "1.2.3.6"); _test_address_range ("1.2.3.4", 29, "1.2.3.1", "1.2.3.3"); _test_address_range ("1.2.3.5", 29, "1.2.3.1", "1.2.3.4"); _test_address_range ("1.2.3.6", 29, "1.2.3.1", "1.2.3.5"); - _test_address_range ("1.2.3.7", 29, "1.2.3.16", "1.2.3.6"); - _test_address_range ("1.2.3.8", 29, "1.2.3.9", "1.2.3.255"); + _test_address_range ("1.2.3.7", 29, "1.2.3.1", "1.2.3.5"); + _test_address_range ("1.2.3.8", 29, "1.2.3.10", "1.2.3.14"); _test_address_range ("1.2.3.9", 29, "1.2.3.10", "1.2.3.14"); - _test_address_range ("255.255.255.248", 29, "255.255.255.249", "255.255.255.239"); + _test_address_range ("255.255.255.248", 29, "255.255.255.250", "255.255.255.254"); _test_address_range ("255.255.255.249", 29, "255.255.255.250", "255.255.255.254"); _test_address_range ("255.255.255.250", 29, "255.255.255.251", "255.255.255.254"); _test_address_range ("255.255.255.251", 29, "255.255.255.252", "255.255.255.254"); _test_address_range ("255.255.255.252", 29, "255.255.255.249", "255.255.255.251"); _test_address_range ("255.255.255.253", 29, "255.255.255.249", "255.255.255.252"); _test_address_range ("255.255.255.254", 29, "255.255.255.249", "255.255.255.253"); - _test_address_range ("255.255.255.255", 29, "255.255.255.8", "255.255.255.254"); + _test_address_range ("255.255.255.255", 29, "255.255.255.249", "255.255.255.253"); _test_address_range ("1.2.3.1", 29, "1.2.3.2", "1.2.3.6"); _test_address_range ("1.2.3.1", 28, "1.2.3.3", "1.2.3.14"); _test_address_range ("1.2.3.1", 26, "1.2.3.8", "1.2.3.62"); - _test_address_range ("192.167.255.255", 24, "192.167.255.8", "192.167.255.254"); - _test_address_range ("192.168.0.0", 24, "192.168.0.1", "192.168.0.247"); + _test_address_range ("192.167.255.255", 24, "192.167.255.1", "192.167.255.245"); + _test_address_range ("192.168.0.0", 24, "192.168.0.10", "192.168.0.254"); _test_address_range ("192.168.0.1", 24, "192.168.0.10", "192.168.0.254"); _test_address_range ("192.168.0.2", 24, "192.168.0.11", "192.168.0.254"); _test_address_range ("192.168.0.99", 24, "192.168.0.108", "192.168.0.254"); @@ -129,19 +130,19 @@ test_address_ranges (void) _test_address_range ("192.168.0.129", 24, "192.168.0.1", "192.168.0.120"); _test_address_range ("192.168.0.130", 24, "192.168.0.1", "192.168.0.121"); _test_address_range ("192.168.0.254", 24, "192.168.0.1", "192.168.0.245"); - _test_address_range ("192.168.0.255", 24, "192.168.0.8", "192.168.0.254"); - _test_address_range ("192.168.1.0", 24, "192.168.1.1", "192.168.1.247"); + _test_address_range ("192.168.0.255", 24, "192.168.0.1", "192.168.0.245"); + _test_address_range ("192.168.1.0", 24, "192.168.1.10", "192.168.1.254"); _test_address_range ("192.168.1.1", 24, "192.168.1.10", "192.168.1.254"); _test_address_range ("192.168.1.2", 24, "192.168.1.11", "192.168.1.254"); _test_address_range ("192.168.1.10", 24, "192.168.1.19", "192.168.1.254"); _test_address_range ("192.168.15.253", 24, "192.168.15.1", "192.168.15.244"); _test_address_range ("192.168.15.254", 24, "192.168.15.1", "192.168.15.245"); - _test_address_range ("192.168.15.255", 24, "192.168.15.8", "192.168.15.254"); - _test_address_range ("192.168.16.0", 24, "192.168.16.1", "192.168.16.247"); + _test_address_range ("192.168.15.255", 24, "192.168.15.1", "192.168.15.245"); + _test_address_range ("192.168.16.0", 24, "192.168.16.10", "192.168.16.254"); _test_address_range ("192.168.16.1", 24, "192.168.16.10", "192.168.16.254"); - _test_address_range ("192.167.255.255", 20, "192.167.255.8", "192.167.255.254"); - _test_address_range ("192.168.0.0", 20, "192.168.0.1", "192.168.0.247"); + _test_address_range ("192.167.255.255", 20, "192.167.255.1", "192.167.255.245"); + _test_address_range ("192.168.0.0", 20, "192.168.0.10", "192.168.0.254"); _test_address_range ("192.168.0.1", 20, "192.168.0.10", "192.168.0.254"); _test_address_range ("192.168.0.2", 20, "192.168.0.11", "192.168.0.254"); _test_address_range ("192.168.0.126", 20, "192.168.0.135", "192.168.0.254"); @@ -150,15 +151,15 @@ test_address_ranges (void) _test_address_range ("192.168.0.129", 20, "192.168.0.1", "192.168.0.120"); _test_address_range ("192.168.0.130", 20, "192.168.0.1", "192.168.0.121"); _test_address_range ("192.168.0.254", 20, "192.168.0.1", "192.168.0.245"); - _test_address_range ("192.168.0.255", 20, "192.168.0.8", "192.168.0.254"); - _test_address_range ("192.168.1.0", 20, "192.168.0.1", "192.168.1.247"); - _test_address_range ("192.168.1.1", 20, "192.168.0.1", "192.168.1.248"); - _test_address_range ("192.168.1.2", 20, "192.168.0.1", "192.168.1.249"); - _test_address_range ("192.168.1.10", 20, "192.168.0.1", "192.168.1.1"); - _test_address_range ("192.168.15.253", 20, "192.168.0.1", "192.168.15.244"); - _test_address_range ("192.168.15.254", 20, "192.168.0.1", "192.168.15.245"); - _test_address_range ("192.168.15.255", 20, "192.168.15.8", "192.168.15.254"); - _test_address_range ("192.168.16.0", 20, "192.168.16.1", "192.168.16.247"); + _test_address_range ("192.168.0.255", 20, "192.168.0.1", "192.168.0.245"); + _test_address_range ("192.168.1.0", 20, "192.168.1.10", "192.168.1.254"); + _test_address_range ("192.168.1.1", 20, "192.168.1.10", "192.168.1.254"); + _test_address_range ("192.168.1.2", 20, "192.168.1.11", "192.168.1.254"); + _test_address_range ("192.168.1.10", 20, "192.168.1.19", "192.168.1.254"); + _test_address_range ("192.168.15.253", 20, "192.168.15.1", "192.168.15.244"); + _test_address_range ("192.168.15.254", 20, "192.168.15.1", "192.168.15.245"); + _test_address_range ("192.168.15.255", 20, "192.168.15.1", "192.168.15.245"); + _test_address_range ("192.168.16.0", 20, "192.168.16.10", "192.168.16.254"); _test_address_range ("192.168.16.1", 20, "192.168.16.10", "192.168.16.254"); } |