diff options
| -rw-r--r-- | netboot/netboot.go | 90 |
1 files changed, 50 insertions, 40 deletions
diff --git a/netboot/netboot.go b/netboot/netboot.go index 6f113b6..e771e3d 100644 --- a/netboot/netboot.go +++ b/netboot/netboot.go @@ -16,6 +16,20 @@ var sleeper = func(d time.Duration) { time.Sleep(d) } +// BootConf is a structure describes everything a host needs to know to boot over network +type BootConf struct { + // NetConf is the network configuration of the client + NetConf + + // BootfileURL is "where is the image (kernel)". + // See RFC5970 section 3.1 for IPv6 and RFC2132 section 9.5 ("Bootfile name") for IPv4 + BootfileURL string + + // BootfileParam is "what arguments should we pass (cmdline)". + // See RFC5970 section 3.2 for IPv6. + BootfileParam []string +} + // RequestNetbootv6 sends a netboot request via DHCPv6 and returns the exchanged packets. Additional modifiers // can be passed to manipulate both solicit and advertise packets. func RequestNetbootv6(ifname string, timeout time.Duration, retries int, modifiers ...dhcpv6.Modifier) ([]dhcpv6.DHCPv6, error) { @@ -81,75 +95,71 @@ func RequestNetbootv4(ifname string, timeout time.Duration, retries int, modifie // ConversationToNetconf extracts network configuration and boot file URL from a // DHCPv6 4-way conversation and returns them, or an error if any. -func ConversationToNetconf(conversation []dhcpv6.DHCPv6) (*NetConf, string, error) { - var reply dhcpv6.DHCPv6 +func ConversationToNetconf(conversation []dhcpv6.DHCPv6) (*BootConf, error) { + var advertise, reply, optionsSource dhcpv6.DHCPv6 for _, m := range conversation { - // look for a REPLY - if m.Type() == dhcpv6.MessageTypeReply { + switch m.Type() { + case dhcpv6.MessageTypeAdvertise: + advertise = m + case dhcpv6.MessageTypeReply: reply = m - break } } if reply == nil { - return nil, "", errors.New("no REPLY received") + return nil, errors.New("no REPLY received") } + + bootconf := &BootConf{} netconf, err := GetNetConfFromPacketv6(reply.(*dhcpv6.Message)) if err != nil { - return nil, "", fmt.Errorf("cannot get netconf from packet: %v", err) + return nil, fmt.Errorf("cannot get netconf from packet: %v", err) } - // look for boot file - var ( - opt dhcpv6.Option - bootfile string - ) - opt = reply.GetOneOption(dhcpv6.OptionBootfileURL) - if opt == nil { - log.Printf("no bootfile URL option found in REPLY, looking for it in ADVERTISE") - // as a fallback, look for bootfile URL in the advertise - var advertise dhcpv6.DHCPv6 - for _, m := range conversation { - // look for an ADVERTISE - if m.Type() == dhcpv6.MessageTypeAdvertise { - advertise = m - break - } - } - if advertise == nil { - return nil, "", errors.New("no ADVERTISE found") - } - opt = advertise.GetOneOption(dhcpv6.OptionBootfileURL) - if opt == nil { - return nil, "", errors.New("no bootfile URL option found in ADVERTISE") + bootconf.NetConf = *netconf + + if reply.GetOneOption(dhcpv6.OptionBootfileURL) != nil { + optionsSource = reply + } else { + log.Printf("no bootfile URL option found in REPLY, fallback to ADVERTISE's value") + if advertise.GetOneOption(dhcpv6.OptionBootfileURL) != nil { + optionsSource = advertise } } - if opt != nil { - obf := opt.(dhcpv6.OptBootFileURL) - bootfile = string(obf) + if optionsSource == nil { + return nil, errors.New("no bootfile URL option found") } - return netconf, bootfile, nil + bootconf.BootfileURL = string(optionsSource.GetOneOption(dhcpv6.OptionBootfileURL).(dhcpv6.OptBootFileURL)) + + if bootfileParamOption := optionsSource.GetOneOption(dhcpv6.OptionBootfileParam); bootfileParamOption != nil { + bootconf.BootfileParam = bootfileParamOption.(dhcpv6.OptBootFileParam) + } + return bootconf, nil } // ConversationToNetconfv4 extracts network configuration and boot file URL from a // DHCPv4 4-way conversation and returns them, or an error if any. -func ConversationToNetconfv4(conversation []*dhcpv4.DHCPv4) (*NetConf, string, error) { +func ConversationToNetconfv4(conversation []*dhcpv4.DHCPv4) (*BootConf, error) { var reply *dhcpv4.DHCPv4 - var bootFileURL string for _, m := range conversation { // look for a BootReply packet of type Offer containing the bootfile URL. // Normally both packets with Message Type OFFER or ACK do contain // the bootfile URL. if m.OpCode == dhcpv4.OpcodeBootReply && m.MessageType() == dhcpv4.MessageTypeOffer { - bootFileURL = m.BootFileName reply = m break } } if reply == nil { - return nil, "", errors.New("no OFFER with valid bootfile URL received") + return nil, errors.New("no OFFER with valid bootfile URL received") } + + bootconf := &BootConf{} netconf, err := GetNetConfFromPacketv4(reply) if err != nil { - return nil, "", fmt.Errorf("could not get netconf: %v", err) + return nil, fmt.Errorf("could not get netconf: %v", err) } - return netconf, bootFileURL, nil + bootconf.NetConf = *netconf + + bootconf.BootfileURL = reply.BootFileName + // TODO: should we support bootfile parameters here somehow? (see netconf.BootfileParam) + return bootconf, nil } |