diff options
Diffstat (limited to 'src/lib/net/net.go')
| -rw-r--r-- | src/lib/net/net.go | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/lib/net/net.go b/src/lib/net/net.go index 737af520b..63074470b 100644 --- a/src/lib/net/net.go +++ b/src/lib/net/net.go @@ -300,9 +300,18 @@ func (c *connBase) SetLinger(sec int) os.Error { // only dealing with IPv4 sockets? As long as the host system // understands IPv6, it's okay to pass IPv4 addresses to the IPv6 // interface. That simplifies our code and is most general. -// If we need to build on a system without IPv6 support, setting -// preferIPv4 here should fall back to the IPv4 socket interface when possible. -const preferIPv4 = false +// Unfortunately, we need to run on kernels built without IPv6 support too. +// So probe the kernel to figure it out. +func kernelSupportsIPv6() bool { + fd, e := syscall.Socket(syscall.AF_INET6, syscall.SOCK_STREAM, syscall.IPPROTO_TCP); + if fd >= 0 { + syscall.Close(fd) + } + return e == 0 +} + +var preferIPv4 = !kernelSupportsIPv6() + func internetSocket(net, laddr, raddr string, proto int64, mode string) (fd *netFD, err os.Error) |