diff options
Diffstat (limited to 'vendor/github.com/jackc/pgproto3/v2/frontend.go')
-rw-r--r-- | vendor/github.com/jackc/pgproto3/v2/frontend.go | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/vendor/github.com/jackc/pgproto3/v2/frontend.go b/vendor/github.com/jackc/pgproto3/v2/frontend.go new file mode 100644 index 000000000..c33dfb084 --- /dev/null +++ b/vendor/github.com/jackc/pgproto3/v2/frontend.go @@ -0,0 +1,201 @@ +package pgproto3 + +import ( + "encoding/binary" + "errors" + "fmt" + "io" +) + +// Frontend acts as a client for the PostgreSQL wire protocol version 3. +type Frontend struct { + cr ChunkReader + w io.Writer + + // Backend message flyweights + authenticationOk AuthenticationOk + authenticationCleartextPassword AuthenticationCleartextPassword + authenticationMD5Password AuthenticationMD5Password + authenticationSASL AuthenticationSASL + authenticationSASLContinue AuthenticationSASLContinue + authenticationSASLFinal AuthenticationSASLFinal + backendKeyData BackendKeyData + bindComplete BindComplete + closeComplete CloseComplete + commandComplete CommandComplete + copyBothResponse CopyBothResponse + copyData CopyData + copyInResponse CopyInResponse + copyOutResponse CopyOutResponse + copyDone CopyDone + dataRow DataRow + emptyQueryResponse EmptyQueryResponse + errorResponse ErrorResponse + functionCallResponse FunctionCallResponse + noData NoData + noticeResponse NoticeResponse + notificationResponse NotificationResponse + parameterDescription ParameterDescription + parameterStatus ParameterStatus + parseComplete ParseComplete + readyForQuery ReadyForQuery + rowDescription RowDescription + portalSuspended PortalSuspended + + bodyLen int + msgType byte + partialMsg bool + authType uint32 +} + +// NewFrontend creates a new Frontend. +func NewFrontend(cr ChunkReader, w io.Writer) *Frontend { + return &Frontend{cr: cr, w: w} +} + +// Send sends a message to the backend. +func (f *Frontend) Send(msg FrontendMessage) error { + _, err := f.w.Write(msg.Encode(nil)) + return err +} + +func translateEOFtoErrUnexpectedEOF(err error) error { + if err == io.EOF { + return io.ErrUnexpectedEOF + } + return err +} + +// Receive receives a message from the backend. The returned message is only valid until the next call to Receive. +func (f *Frontend) Receive() (BackendMessage, error) { + if !f.partialMsg { + header, err := f.cr.Next(5) + if err != nil { + return nil, translateEOFtoErrUnexpectedEOF(err) + } + + f.msgType = header[0] + f.bodyLen = int(binary.BigEndian.Uint32(header[1:])) - 4 + f.partialMsg = true + } + + msgBody, err := f.cr.Next(f.bodyLen) + if err != nil { + return nil, translateEOFtoErrUnexpectedEOF(err) + } + + f.partialMsg = false + + var msg BackendMessage + switch f.msgType { + case '1': + msg = &f.parseComplete + case '2': + msg = &f.bindComplete + case '3': + msg = &f.closeComplete + case 'A': + msg = &f.notificationResponse + case 'c': + msg = &f.copyDone + case 'C': + msg = &f.commandComplete + case 'd': + msg = &f.copyData + case 'D': + msg = &f.dataRow + case 'E': + msg = &f.errorResponse + case 'G': + msg = &f.copyInResponse + case 'H': + msg = &f.copyOutResponse + case 'I': + msg = &f.emptyQueryResponse + case 'K': + msg = &f.backendKeyData + case 'n': + msg = &f.noData + case 'N': + msg = &f.noticeResponse + case 'R': + var err error + msg, err = f.findAuthenticationMessageType(msgBody) + if err != nil { + return nil, err + } + case 's': + msg = &f.portalSuspended + case 'S': + msg = &f.parameterStatus + case 't': + msg = &f.parameterDescription + case 'T': + msg = &f.rowDescription + case 'V': + msg = &f.functionCallResponse + case 'W': + msg = &f.copyBothResponse + case 'Z': + msg = &f.readyForQuery + default: + return nil, fmt.Errorf("unknown message type: %c", f.msgType) + } + + err = msg.Decode(msgBody) + return msg, err +} + +// Authentication message type constants. +// See src/include/libpq/pqcomm.h for all +// constants. +const ( + AuthTypeOk = 0 + AuthTypeCleartextPassword = 3 + AuthTypeMD5Password = 5 + AuthTypeSCMCreds = 6 + AuthTypeGSS = 7 + AuthTypeGSSCont = 8 + AuthTypeSSPI = 9 + AuthTypeSASL = 10 + AuthTypeSASLContinue = 11 + AuthTypeSASLFinal = 12 +) + +func (f *Frontend) findAuthenticationMessageType(src []byte) (BackendMessage, error) { + if len(src) < 4 { + return nil, errors.New("authentication message too short") + } + f.authType = binary.BigEndian.Uint32(src[:4]) + + switch f.authType { + case AuthTypeOk: + return &f.authenticationOk, nil + case AuthTypeCleartextPassword: + return &f.authenticationCleartextPassword, nil + case AuthTypeMD5Password: + return &f.authenticationMD5Password, nil + case AuthTypeSCMCreds: + return nil, errors.New("AuthTypeSCMCreds is unimplemented") + case AuthTypeGSS: + return nil, errors.New("AuthTypeGSS is unimplemented") + case AuthTypeGSSCont: + return nil, errors.New("AuthTypeGSSCont is unimplemented") + case AuthTypeSSPI: + return nil, errors.New("AuthTypeSSPI is unimplemented") + case AuthTypeSASL: + return &f.authenticationSASL, nil + case AuthTypeSASLContinue: + return &f.authenticationSASLContinue, nil + case AuthTypeSASLFinal: + return &f.authenticationSASLFinal, nil + default: + return nil, fmt.Errorf("unknown authentication type: %d", f.authType) + } +} + +// GetAuthType returns the authType used in the current state of the frontend. +// See SetAuthType for more information. +func (f *Frontend) GetAuthType() uint32 { + return f.authType +} |