mirror of
https://github.com/status-im/consul.git
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4f5d5020b8
* Add updated github.com/miekg/dns to go modules
* Add updated github.com/miekg/dns to vendor
* Fix github.com/miekg/dns api breakage
* Decrease size when trimming UDP packets
Need more room for the header(?), if we don't decrease the size we get an
"overflow unpacking uint32" from the dns library
* Fix dns truncate tests with api changes
* Make windows build working again. Upgrade x/sys and x/crypto and vendor
This upgrade is needed because of API breakage in x/sys introduced
by the minimal x/sys dependency of miekg/dns
This API breakage has been fixed in commit
855e68c859
55 lines
1.8 KiB
Go
55 lines
1.8 KiB
Go
package dns
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// MsgAcceptFunc is used early in the server code to accept or reject a message with RcodeFormatError.
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// It returns a MsgAcceptAction to indicate what should happen with the message.
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type MsgAcceptFunc func(dh Header) MsgAcceptAction
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// DefaultMsgAcceptFunc checks the request and will reject if:
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//
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// * isn't a request (don't respond in that case).
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// * opcode isn't OpcodeQuery or OpcodeNotify
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// * Zero bit isn't zero
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// * has more than 1 question in the question section
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// * has more than 1 RR in the Answer section
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// * has more than 0 RRs in the Authority section
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// * has more than 2 RRs in the Additional section
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var DefaultMsgAcceptFunc MsgAcceptFunc = defaultMsgAcceptFunc
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// MsgAcceptAction represents the action to be taken.
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type MsgAcceptAction int
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const (
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MsgAccept MsgAcceptAction = iota // Accept the message
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MsgReject // Reject the message with a RcodeFormatError
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MsgIgnore // Ignore the error and send nothing back.
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MsgRejectNotImplemented // Reject the message with a RcodeNotImplemented
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)
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func defaultMsgAcceptFunc(dh Header) MsgAcceptAction {
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if isResponse := dh.Bits&_QR != 0; isResponse {
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return MsgIgnore
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}
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// Don't allow dynamic updates, because then the sections can contain a whole bunch of RRs.
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opcode := int(dh.Bits>>11) & 0xF
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if opcode != OpcodeQuery && opcode != OpcodeNotify {
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return MsgRejectNotImplemented
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}
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if dh.Qdcount != 1 {
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return MsgReject
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}
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// NOTIFY requests can have a SOA in the ANSWER section. See RFC 1996 Section 3.7 and 3.11.
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if dh.Ancount > 1 {
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return MsgReject
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}
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// IXFR request could have one SOA RR in the NS section. See RFC 1995, section 3.
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if dh.Nscount > 1 {
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return MsgReject
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}
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if dh.Arcount > 2 {
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return MsgReject
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}
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return MsgAccept
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}
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