From 1cd183691735126aa3c916c3e2417e2edd104d1d Mon Sep 17 00:00:00 2001 From: iphydf Date: Mon, 27 Aug 2018 16:06:40 +0000 Subject: Avoid recursion in `ip_is_lan` and `ip_is_local`. --- toxcore/LAN_discovery.c | 103 +++++++++++++++++++++++++----------------------- 1 file changed, 54 insertions(+), 49 deletions(-) (limited to 'toxcore/LAN_discovery.c') diff --git a/toxcore/LAN_discovery.c b/toxcore/LAN_discovery.c index fd5bca34..aeeea566 100644 --- a/toxcore/LAN_discovery.c +++ b/toxcore/LAN_discovery.c @@ -272,71 +272,77 @@ static IP broadcast_ip(Family family_socket, Family family_broadcast) return ip; } +static bool ip4_is_local(IP4 ip4) +{ + /* Loopback. */ + return ip4.uint8[0] == 127; +} + /* Is IP a local ip or not. */ bool ip_is_local(IP ip) { if (net_family_is_ipv4(ip.family)) { - IP4 ip4 = ip.ip.v4; + return ip4_is_local(ip.ip.v4); + } - /* Loopback. */ - if (ip4.uint8[0] == 127) { - return 1; - } - } else { - /* embedded IPv4-in-IPv6 */ - if (ipv6_ipv4_in_v6(ip.ip.v6)) { - IP ip4; - ip4.family = net_family_ipv4; - ip4.ip.v4.uint32 = ip.ip.v6.uint32[3]; - return ip_is_local(ip4); - } + /* embedded IPv4-in-IPv6 */ + if (ipv6_ipv4_in_v6(ip.ip.v6)) { + IP4 ip4; + ip4.uint32 = ip.ip.v6.uint32[3]; + return ip4_is_local(ip4); + } - /* localhost in IPv6 (::1) */ - if (ip.ip.v6.uint64[0] == 0 && ip.ip.v6.uint32[2] == 0 && ip.ip.v6.uint32[3] == net_htonl(1)) { - return 1; - } + /* localhost in IPv6 (::1) */ + if (ip.ip.v6.uint64[0] == 0 && ip.ip.v6.uint32[2] == 0 && ip.ip.v6.uint32[3] == net_htonl(1)) { + return true; } - return 0; + return false; } -bool ip_is_lan(IP ip) +static bool ip4_is_lan(IP4 ip4) { - if (ip_is_local(ip)) { + /* 10.0.0.0 to 10.255.255.255 range. */ + if (ip4.uint8[0] == 10) { return true; } - if (net_family_is_ipv4(ip.family)) { - IP4 ip4 = ip.ip.v4; + /* 172.16.0.0 to 172.31.255.255 range. */ + if (ip4.uint8[0] == 172 && ip4.uint8[1] >= 16 && ip4.uint8[1] <= 31) { + return true; + } - /* 10.0.0.0 to 10.255.255.255 range. */ - if (ip4.uint8[0] == 10) { - return true; - } + /* 192.168.0.0 to 192.168.255.255 range. */ + if (ip4.uint8[0] == 192 && ip4.uint8[1] == 168) { + return true; + } - /* 172.16.0.0 to 172.31.255.255 range. */ - if (ip4.uint8[0] == 172 && ip4.uint8[1] >= 16 && ip4.uint8[1] <= 31) { - return true; - } + /* 169.254.1.0 to 169.254.254.255 range. */ + if (ip4.uint8[0] == 169 && ip4.uint8[1] == 254 && ip4.uint8[2] != 0 + && ip4.uint8[2] != 255) { + return true; + } - /* 192.168.0.0 to 192.168.255.255 range. */ - if (ip4.uint8[0] == 192 && ip4.uint8[1] == 168) { - return true; - } + /* RFC 6598: 100.64.0.0 to 100.127.255.255 (100.64.0.0/10) + * (shared address space to stack another layer of NAT) */ + if ((ip4.uint8[0] == 100) && ((ip4.uint8[1] & 0xC0) == 0x40)) { + return true; + } - /* 169.254.1.0 to 169.254.254.255 range. */ - if (ip4.uint8[0] == 169 && ip4.uint8[1] == 254 && ip4.uint8[2] != 0 - && ip4.uint8[2] != 255) { - return true; - } + return false; +} - /* RFC 6598: 100.64.0.0 to 100.127.255.255 (100.64.0.0/10) - * (shared address space to stack another layer of NAT) */ - if ((ip4.uint8[0] == 100) && ((ip4.uint8[1] & 0xC0) == 0x40)) { - return true; - } - } else if (net_family_is_ipv6(ip.family)) { +bool ip_is_lan(IP ip) +{ + if (ip_is_local(ip)) { + return true; + } + + if (net_family_is_ipv4(ip.family)) { + return ip4_is_lan(ip.ip.v4); + } + if (net_family_is_ipv6(ip.family)) { /* autogenerated for each interface: FE80::* (up to FEBF::*) FF02::1 is - according to RFC 4291 - multicast all-nodes link-local */ if (((ip.ip.v6.uint8[0] == 0xFF) && (ip.ip.v6.uint8[1] < 3) && (ip.ip.v6.uint8[15] == 1)) || @@ -346,10 +352,9 @@ bool ip_is_lan(IP ip) /* embedded IPv4-in-IPv6 */ if (ipv6_ipv4_in_v6(ip.ip.v6)) { - IP ip4; - ip4.family = net_family_ipv4; - ip4.ip.v4.uint32 = ip.ip.v6.uint32[3]; - return ip_is_lan(ip4); + IP4 ip4; + ip4.uint32 = ip.ip.v6.uint32[3]; + return ip4_is_lan(ip4); } } -- cgit v1.2.3