text: // Copyright 2012 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  package ipv4
  
  // TOS returns the type-of-service field value for outgoing packets.
  func (c *genericOpt) TOS() (int, error) {
  	if !c.ok() {
  		return 0, errInvalidConn
  	}
  	so, ok := sockOpts[ssoTOS]
  	if !ok {
  		return 0, errNotImplemented
  	}
  	return so.GetInt(c.Conn)
  }
  
  // SetTOS sets the type-of-service field value for future outgoing
  // packets.
  func (c *genericOpt) SetTOS(tos int) error {
  	if !c.ok() {
  		return errInvalidConn
  	}
  	so, ok := sockOpts[ssoTOS]
  	if !ok {
  		return errNotImplemented
  	}
  	return so.SetInt(c.Conn, tos)
  }
  
  // TTL returns the time-to-live field value for outgoing packets.
  func (c *genericOpt) TTL() (int, error) {
  	if !c.ok() {
  		return 0, errInvalidConn
  	}
  	so, ok := sockOpts[ssoTTL]
  	if !ok {
  		return 0, errNotImplemented
  	}
  	return so.GetInt(c.Conn)
  }
  
  // SetTTL sets the time-to-live field value for future outgoing
  // packets.
  func (c *genericOpt) SetTTL(ttl int) error {
  	if !c.ok() {
  		return errInvalidConn
  	}
  	so, ok := sockOpts[ssoTTL]
  	if !ok {
  		return errNotImplemented
  	}
  	return so.SetInt(c.Conn, ttl)
  }
  