1 files changed, 218 insertions, 0 deletions
diff --git a/vendor/github.com/ishidawataru/sctp/ipsock_linux.go b/vendor/github.com/ishidawataru/sctp/ipsock_linux.go
new file mode 100644
index 000000000..f5632b72d
--- /dev/null
+++ b/vendor/github.com/ishidawataru/sctp/ipsock_linux.go
@@ -0,0 +1,218 @@
+package sctp
+
+import (
+	"net"
+	"os"
+	"sync"
+	"syscall"
+)
+
+//from https://github.com/golang/go
+// Boolean to int.
+func boolint(b bool) int {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+//from https://github.com/golang/go
+func ipToSockaddr(family int, ip net.IP, port int, zone string) (syscall.Sockaddr, error) {
+	switch family {
+	case syscall.AF_INET:
+		if len(ip) == 0 {
+			ip = net.IPv4zero
+		}
+		ip4 := ip.To4()
+		if ip4 == nil {
+			return nil, &net.AddrError{Err: "non-IPv4 address", Addr: ip.String()}
+		}
+		sa := &syscall.SockaddrInet4{Port: port}
+		copy(sa.Addr[:], ip4)
+		return sa, nil
+	case syscall.AF_INET6:
+		// In general, an IP wildcard address, which is either
+		// "0.0.0.0" or "::", means the entire IP addressing
+		// space. For some historical reason, it is used to
+		// specify "any available address" on some operations
+		// of IP node.
+		//
+		// When the IP node supports IPv4-mapped IPv6 address,
+		// we allow an listener to listen to the wildcard
+		// address of both IP addressing spaces by specifying
+		// IPv6 wildcard address.
+		if len(ip) == 0 || ip.Equal(net.IPv4zero) {
+			ip = net.IPv6zero
+		}
+		// We accept any IPv6 address including IPv4-mapped
+		// IPv6 address.
+		ip6 := ip.To16()
+		if ip6 == nil {
+			return nil, &net.AddrError{Err: "non-IPv6 address", Addr: ip.String()}
+		}
+		//we set ZoneId to 0, as currently we use this functon only to probe the IP capabilities of the host
+		//if real Zone handling is required, the zone cache implementation in golang/net should be pulled here
+		sa := &syscall.SockaddrInet6{Port: port, ZoneId: 0}
+		copy(sa.Addr[:], ip6)
+		return sa, nil
+	}
+	return nil, &net.AddrError{Err: "invalid address family", Addr: ip.String()}
+}
+
+//from https://github.com/golang/go
+func sockaddr(a *net.TCPAddr, family int) (syscall.Sockaddr, error) {
+	if a == nil {
+		return nil, nil
+	}
+	return ipToSockaddr(family, a.IP, a.Port, a.Zone)
+}
+
+//from https://github.com/golang/go
+type ipStackCapabilities struct {
+	sync.Once             // guards following
+	ipv4Enabled           bool
+	ipv6Enabled           bool
+	ipv4MappedIPv6Enabled bool
+}
+
+//from https://github.com/golang/go
+var ipStackCaps ipStackCapabilities
+
+//from https://github.com/golang/go
+// supportsIPv4 reports whether the platform supports IPv4 networking
+// functionality.
+func supportsIPv4() bool {
+	ipStackCaps.Once.Do(ipStackCaps.probe)
+	return ipStackCaps.ipv4Enabled
+}
+
+//from https://github.com/golang/go
+// supportsIPv6 reports whether the platform supports IPv6 networking
+// functionality.
+func supportsIPv6() bool {
+	ipStackCaps.Once.Do(ipStackCaps.probe)
+	return ipStackCaps.ipv6Enabled
+}
+
+//from https://github.com/golang/go
+// supportsIPv4map reports whether the platform supports mapping an
+// IPv4 address inside an IPv6 address at transport layer
+// protocols. See RFC 4291, RFC 4038 and RFC 3493.
+func supportsIPv4map() bool {
+	ipStackCaps.Once.Do(ipStackCaps.probe)
+	return ipStackCaps.ipv4MappedIPv6Enabled
+}
+
+//from https://github.com/golang/go
+// Probe probes IPv4, IPv6 and IPv4-mapped IPv6 communication
+// capabilities which are controlled by the IPV6_V6ONLY socket option
+// and kernel configuration.
+//
+// Should we try to use the IPv4 socket interface if we're only
+// dealing with IPv4 sockets? As long as the host system understands
+// IPv4-mapped IPv6, it's okay to pass IPv4-mapeed IPv6 addresses to
+// the IPv6 interface. That simplifies our code and is most
+// general. Unfortunately, we need to run on kernels built without
+// IPv6 support too. So probe the kernel to figure it out.
+func (p *ipStackCapabilities) probe() {
+	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
+	switch err {
+	case syscall.EAFNOSUPPORT, syscall.EPROTONOSUPPORT:
+	case nil:
+		syscall.Close(s)
+		p.ipv4Enabled = true
+	}
+	var probes = []struct {
+		laddr net.TCPAddr
+		value int
+	}{
+		// IPv6 communication capability
+		{laddr: net.TCPAddr{IP: net.IPv6loopback}, value: 1},
+		// IPv4-mapped IPv6 address communication capability
+		{laddr: net.TCPAddr{IP: net.IPv4(127, 0, 0, 1)}, value: 0},
+	}
+
+	for i := range probes {
+		s, err := syscall.Socket(syscall.AF_INET6, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
+		if err != nil {
+			continue
+		}
+		defer syscall.Close(s)
+		syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, probes[i].value)
+		sa, err := sockaddr(&(probes[i].laddr), syscall.AF_INET6)
+		if err != nil {
+			continue
+		}
+		if err := syscall.Bind(s, sa); err != nil {
+			continue
+		}
+		if i == 0 {
+			p.ipv6Enabled = true
+		} else {
+			p.ipv4MappedIPv6Enabled = true
+		}
+	}
+}
+
+//from https://github.com/golang/go
+//Change: we check the first IP address in the list of candidate SCTP IP addresses
+func (a *SCTPAddr) isWildcard() bool {
+	if a == nil {
+		return true
+	}
+	if 0 == len(a.IPAddrs) {
+		return true
+	}
+
+	return a.IPAddrs[0].IP.IsUnspecified()
+}
+
+func (a *SCTPAddr) family() int {
+	if a != nil {
+		for _, ip := range a.IPAddrs {
+			if ip.IP.To4() == nil {
+				return syscall.AF_INET6
+			}
+		}
+	}
+	return syscall.AF_INET
+}
+
+//from https://github.com/golang/go
+func favoriteAddrFamily(network string, laddr *SCTPAddr, raddr *SCTPAddr, mode string) (family int, ipv6only bool) {
+	switch network[len(network)-1] {
+	case '4':
+		return syscall.AF_INET, false
+	case '6':
+		return syscall.AF_INET6, true
+	}
+
+	if mode == "listen" && (laddr == nil || laddr.isWildcard()) {
+		if supportsIPv4map() || !supportsIPv4() {
+			return syscall.AF_INET6, false
+		}
+		if laddr == nil {
+			return syscall.AF_INET, false
+		}
+		return laddr.family(), false
+	}
+
+	if (laddr == nil || laddr.family() == syscall.AF_INET) &&
+		(raddr == nil || raddr.family() == syscall.AF_INET) {
+		return syscall.AF_INET, false
+	}
+	return syscall.AF_INET6, false
+}
+
+//from https://github.com/golang/go
+//Changes: it is for SCTP only
+func setDefaultSockopts(s int, family int, ipv6only bool) error {
+	if family == syscall.AF_INET6 {
+		// Allow both IP versions even if the OS default
+		// is otherwise. Note that some operating systems
+		// never admit this option.
+		syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, boolint(ipv6only))
+	}
+	// Allow broadcast.
+	return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1))
+}