func (s *sniffingRouter) RouteBackend() error {
// route the next message from backend to frotnend,
// blocking and flushing if necessary
err := s.be.Next(&s.beBuf)
if err != nil {
return err
}
if proto.IsBackendKeyData(&s.beBuf) {
beInfo, err := proto.ReadBackendKeyData(&s.beBuf)
if err != nil {
return err
}
s.backendPid = beInfo.BackendPid
s.secretKey = beInfo.SecretKey
}
var clone core.Message
clone.InitFromMessage(&s.beBuf)
s.beCh <- &clone
err = s.fe.Send(&s.beBuf)
if !s.be.HasNext() {
return s.fe.Flush()
}
return nil
}
func RejectFrontendConnection(c net.Conn) {
var message fbcore.Message
initFatalMessage(&message, "57A01", "no server connection available")
_, _ = message.WriteTo(c)
_ = c.Close()
}
func (c *FrontendConnection) sendNotification(n *pq.Notification) error {
var message fbcore.Message
buf := &bytes.Buffer{}
fbbuf.WriteInt32(buf, int32(n.BePid))
fbbuf.WriteCString(buf, n.Channel)
fbbuf.WriteCString(buf, n.Extra)
message.InitFromBytes(fbproto.MsgNotificationResponseA, buf.Bytes())
return c.WriteAndFlush(&message)
}
func initFatalMessage(message *fbcore.Message, sqlstate, errorMessage string) {
buf := &bytes.Buffer{}
buf.WriteByte('S')
fbbuf.WriteCString(buf, "FATAL")
buf.WriteByte('C')
fbbuf.WriteCString(buf, sqlstate)
buf.WriteByte('M')
fbbuf.WriteCString(buf, errorMessage)
buf.WriteByte('\x00')
message.InitFromBytes(fbproto.MsgErrorResponseE, buf.Bytes())
}
func (c *FrontendConnection) readExecuteMessage(msg *fbcore.Message) error {
statementName, err := fbbuf.ReadCString(msg.Payload())
if err != nil {
return err
}
if statementName != "" {
return fmt.Errorf("attempted to use statement name %q; only unnamed statements are supported")
}
// ignore maxRowCount
_, err = fbbuf.ReadInt32(msg.Payload())
// TODO: ensure we're at the end of the packet
return err
}
func (r trivialSelectResult) Respond(f Frontend) error {
var msg fbcore.Message
buf := &bytes.Buffer{}
fbbuf.WriteInt16(buf, 1)
fbbuf.WriteInt32(buf, 1)
buf.WriteByte('1')
msg.InitFromBytes(fbproto.MsgDataRowD, buf.Bytes())
err := f.WriteMessage(&msg)
if err != nil {
return err
}
return commandComplete("SELECT").Respond(f)
}
func (c *FrontendConnection) readBindMessage(msg *fbcore.Message) error {
portalName, err := fbbuf.ReadCString(msg.Payload())
if err != nil {
return err
}
if portalName != "" {
return fmt.Errorf("attempted to bind to a named portal %q; only the unnamed portal is supported")
}
statementName, err := fbbuf.ReadCString(msg.Payload())
if err != nil {
return err
}
if statementName != "" {
return fmt.Errorf("attempted to bind statement %q, even though it has not been parsed yet", statementName)
}
numParamFormats, err := fbbuf.ReadInt16(msg.Payload())
if err != nil {
return err
}
if numParamFormats != 0 {
return fmt.Errorf("the number of parameter formats (%d) does not match the number of parameters in the query (0)", numParamFormats)
}
numParameters, err := fbbuf.ReadInt16(msg.Payload())
if err != nil {
return err
}
if numParameters != 0 {
return fmt.Errorf("the number of parameters provided by the client (%d) does not match the number of parameters in the query (0)", numParameters)
}
// TODO: ensure we're at the end of the packet
return nil
}
func (qr errorResponse) Respond(f Frontend) error {
var message fbcore.Message
buf := &bytes.Buffer{}
buf.WriteByte('S')
fbbuf.WriteCString(buf, "ERROR")
buf.WriteByte('C')
fbbuf.WriteCString(buf, qr.sqlstate)
buf.WriteByte('M')
fbbuf.WriteCString(buf, qr.errorMessage)
buf.WriteByte('\x00')
message.InitFromBytes(fbproto.MsgErrorResponseE, buf.Bytes())
return f.WriteMessage(&message)
}
func (c *FrontendConnection) readDescribeMessage(msg *fbcore.Message) (byte, error) {
typ, err := fbbuf.ReadByte(msg.Payload())
if err != nil {
return 0, err
}
if typ != 'S' && typ != 'P' {
return 0, fmt.Errorf("invalid type %q", typ)
}
statementName, err := fbbuf.ReadCString(msg.Payload())
if err != nil {
return 0, err
}
if statementName != "" {
return 0, fmt.Errorf("tried to use statement/portal name %q; only unnamed statements and portals are supported")
}
// TODO: ensure we're at the end of the packet
return typ, nil
}
func (s *sniffingRouter) RouteFrontend() (err error) {
// route the next message from frontend to backend,
// blocking and flushing if necessary
err = s.fe.Next(&s.feBuf)
if err != nil {
return
}
var clone core.Message
clone.InitFromMessage(&s.feBuf)
s.feCh <- &clone
err = s.be.Send(&s.feBuf)
if err != nil {
return
}
if !s.fe.HasNext() {
return s.be.Flush()
}
return
}
// Process a log message, sending it to the client.
func processLogMsg(die dieCh, primary *logplexc.Client, audit *logplexc.Client,
msgInit msgInit, sr *serveRecord, exit exitFn) {
var m core.Message
for {
// Poll request to exit
select {
case <-die:
return
default:
break
}
msgInit(&m, exit)
// Refuse to handle any log message above an arbitrary
// size. Furthermore, exit the worker, closing the0
// connection, so that the client doesn't even bother
// to wait for this process to drain the oversized
// item and anything following it; these will be
// dropped. It's on the client to gracefully handle
// the error and re-connect after this happens.
if m.Size() > 1*MB {
exit("client %q sent oversized log record")
}
payload, err := m.Force()
if err != nil {
exit("could not retrieve payload of message: %v",
err)
}
var lr logRecord
parseLogRecord(&lr, payload, exit)
routeLogRecord(&lr, primary, audit, sr, exit)
}
}
func (c *FrontendConnection) discardUntilSync() error {
var message fbcore.Message
for {
err := c.stream.Next(&message)
if err != nil {
return err
}
switch message.MsgType() {
case fbproto.MsgSyncS:
_, err = message.Force()
return nil
default:
_, err = message.Force()
}
if err != nil {
return err
}
}
}
func (c *FrontendConnection) readParseMessage(msg *fbcore.Message) (queryString string, err error) {
statementName, err := fbbuf.ReadCString(msg.Payload())
if err != nil {
return "", err
}
if statementName != "" {
return "", fmt.Errorf("attempted to use statement name %q; only unnamed statements are supported")
}
queryString, err = fbbuf.ReadCString(msg.Payload())
if err != nil {
return "", err
}
numParamTypes, err := fbbuf.ReadInt16(msg.Payload())
if err != nil {
return "", err
}
if numParamTypes != 0 {
return "", fmt.Errorf("attempted to prepare a statement with %d param types", numParamTypes)
}
// TODO: ensure we're at the end of the packet
return queryString, nil
}
func (c *FrontendConnection) auth(dbcfg VirtualDatabaseConfiguration, sm *fbproto.StartupMessage) bool {
authFailed := func(sqlstate, format string, v ...interface{}) bool {
var msg fbcore.Message
message := fmt.Sprintf(format, v...)
initFatalMessage(&msg, sqlstate, message)
_ = c.WriteMessage(&msg)
_ = c.FlushStream()
return false
}
username, ok := sm.Params["user"]
if !ok {
return authFailed("08P01", `required startup parameter "user" nor present in startup packet`)
}
dbname, ok := sm.Params["database"]
if !ok {
dbname = username
}
authMethod, ok := dbcfg.FindDatabase(dbname)
if !ok {
return authFailed("3D000", "database %q does not exist", dbname)
}
switch authMethod {
case "trust":
return true
case "md5":
// handled below
default:
elog.Errorf("unrecognized authentication method %q", authMethod)
return authFailed("XX000", "internal error")
}
salt := make([]byte, 4)
_, err := rand.Read(salt)
if err != nil {
elog.Errorf("could not generate random salt: %s", err)
return authFailed("XX000", "internal error")
}
var msg fbcore.Message
buf := &bytes.Buffer{}
fbbuf.WriteInt32(buf, 5)
buf.Write(salt)
msg.InitFromBytes(fbproto.MsgAuthenticationMD5PasswordR, buf.Bytes())
err = c.WriteAndFlush(&msg)
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
err = c.stream.Next(&msg)
if err == io.EOF {
elog.Debugf("EOF during startup sequence")
return false
} else if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
if msg.MsgType() != fbproto.MsgPasswordMessageP {
return authFailed("08P01", "unexpected response %x", msg.MsgType())
}
// don't bother with messages which are clearly too big
if msg.Size() > 100 {
return authFailed("28001", "password authentication failed for user %q", username)
}
password, err := msg.Force()
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
success, err := dbcfg.MD5Auth(dbname, username, salt, password)
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
if !success {
return authFailed("28001", "password authentication failed for user %q", username)
}
return true
}
func (qr bindComplete) Respond(f Frontend) error {
var message fbcore.Message
message.InitFromBytes(fbproto.MsgBindComplete2, []byte{})
return f.WriteMessage(&message)
}
// This is the main loop for processing messages from the frontend. Note that
// we must *never* send anything directly to the connection; all communication
// must go through queryResultCh. We're also not responsible for doing any
// cleanup in any case; that'll all be handled by mainLoop.
func (c *FrontendConnection) queryProcessingMainLoop() {
var unnamedStatement FrontendQuery
var queryResult QueryResult
var sendReadyForQuery bool
sessionLoop:
for {
var message fbcore.Message
err := c.stream.Next(&message)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
queryResult = nil
sendReadyForQuery = false
switch message.MsgType() {
case fbproto.MsgParseP:
queryString, err := c.readParseMessage(&message)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
unnamedStatement, err = ParseQuery(queryString)
if err != nil {
queryResult = NewErrorResponse("42601", err.Error())
c.queryResultCh <- queryResultSync{queryResult, false}
err = c.discardUntilSync()
if err != nil {
c.setSessionError(err)
break sessionLoop
}
queryResult = NewNopResponder()
sendReadyForQuery = true
} else {
queryResult = NewParseComplete()
sendReadyForQuery = false
}
case fbproto.MsgExecuteE:
err = c.readExecuteMessage(&message)
if unnamedStatement == nil {
err = fmt.Errorf("attempted to execute the unnamed prepared statement when one does not exist")
c.setSessionError(err)
break sessionLoop
}
queryResult, err = unnamedStatement.Process(c)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
sendReadyForQuery = false
// Disallow reuse; not exactly following the protocol to the letter,
// but apps reusing the unnamed statement should not exist, either.
unnamedStatement = nil
case fbproto.MsgDescribeD:
_, err = c.readDescribeMessage(&message)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
if unnamedStatement == nil {
err = fmt.Errorf("attempted to describe the unnamed prepared statement when one does not exist")
c.setSessionError(err)
break sessionLoop
}
queryResult = unnamedStatement.Describe()
sendReadyForQuery = false
case fbproto.MsgBindB:
err = c.readBindMessage(&message)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
queryResult = NewBindComplete()
sendReadyForQuery = false
case fbproto.MsgSyncS:
queryResult = NewNopResponder()
sendReadyForQuery = true
case fbproto.MsgQueryQ:
query, err := fbproto.ReadQuery(&message)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
q, err := ParseQuery(query.Query)
if err != nil {
queryResult = NewErrorResponse("42601", err.Error())
} else {
resultDescription := q.Describe()
// Special case in SimpleQuery processing: we only send the
// Describe() response over if it's a RowDescription. This is
// somewhat magical and very weird, but that's what the upstream
// server does, so we ought to do the same thing here.
if DescriptionIsRowDescription(resultDescription) {
c.queryResultCh <- queryResultSync{resultDescription, false}
}
queryResult, err = q.Process(c)
if err != nil {
c.setSessionError(err)
break sessionLoop
}
}
sendReadyForQuery = true
// Simple Query also clears the unnamed statement; this matches
// what Postgres does.
unnamedStatement = nil
case fbproto.MsgTerminateX:
c.setSessionError(errGracefulTermination)
break sessionLoop
default:
c.setSessionError(fmt.Errorf("unrecognized frontend message type 0x%x", message.MsgType()))
break sessionLoop
}
if queryResult != nil {
c.queryResultCh <- queryResultSync{queryResult, sendReadyForQuery}
}
}
// wake mainLoop to clean up
close(c.queryResultCh)
}
func (qr noData) Respond(f Frontend) error {
var message fbcore.Message
message.InitFromBytes(fbproto.MsgNoDataN, []byte{})
return f.WriteMessage(&message)
}
func (c *FrontendConnection) startup(startupParameters map[string]string, dbcfg VirtualDatabaseConfiguration) bool {
var message fbcore.Message
var err error
for {
err = c.stream.Next(&message)
if err != nil {
elog.Logf("error while reading startup packet: %s", err)
return false
}
if fbproto.IsStartupMessage(&message) {
break
} else if fbproto.IsSSLRequest(&message) {
_, err = message.Force()
if err != nil {
elog.Logf("error while reading SSLRequest: %s", err)
return false
}
err = c.stream.SendSSLRequestResponse(fbcore.RejectSSLRequest)
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
err = c.FlushStream()
if err != nil {
elog.Logf("error during startup sequence: %s", err)
}
} else if fbproto.IsCancelRequest(&message) {
_ = c.stream.Close()
return false
} else {
elog.Warningf("unrecognized frontend message type 0x%x during startup", message.MsgType())
return false
}
}
sm, err := fbproto.ReadStartupMessage(&message)
if err != nil {
elog.Logf("error while reading startup packet: %s", err)
return false
}
if !c.auth(dbcfg, sm) {
// error already logged
_ = c.stream.Close()
return false
}
fbproto.InitAuthenticationOk(&message)
err = c.WriteMessage(&message)
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
for k, v := range startupParameters {
buf := &bytes.Buffer{}
fbbuf.WriteCString(buf, k)
fbbuf.WriteCString(buf, v)
message.InitFromBytes(fbproto.MsgParameterStatusS, buf.Bytes())
err = c.WriteMessage(&message)
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
}
fbproto.InitReadyForQuery(&message, fbproto.RfqIdle)
err = c.WriteMessage(&message)
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
err = c.FlushStream()
if err != nil {
elog.Logf("error during startup sequence: %s", err)
return false
}
return true
}
func (eqr emptyQueryResponse) Respond(f Frontend) error {
var message fbcore.Message
message.InitFromBytes(fbproto.MsgEmptyQueryResponseI, nil)
return f.WriteMessage(&message)
}
// Process the identity ('I') message, reporting the identity therein.
func processIdentMsg(msgInit msgInit, exit exitFn) string {
var m core.Message
msgInit(&m, exit)
// Read the remote system identifier string
if m.MsgType() != 'I' {
exit("expected identification ('I') message, "+
"but received %c", m.MsgType())
}
// hard-coded lengh limit, but it's very generous
if m.Size() > 10*KB {
log.Printf("oversized message string, msg size is %d",
m.Size())
}
s, err := buf.ReadCString(m.Payload())
if err != nil {
exit("couldn't read identification string: %v",
err)
}
return s
}
// Read the version message, calling exit if this is not a supported
// version.
func processVerMsg(msgInit msgInit, exit exitFn) {
var m core.Message
msgInit(&m, exit)
if m.MsgType() != 'V' {
exit("expected version ('V') message, "+
"but received %c", m.MsgType())
}
// hard-coded lengh limit, but it's very generous
if m.Size() > 10*KB {
log.Printf("oversized message string, msg size is %d",
m.Size())
}
s, err := buf.ReadCString(m.Payload())
if err != nil {
exit("couldn't read version string: %v", err)
}
if !(strings.HasPrefix(s, "PG-9.0") ||
strings.HasPrefix(s, "PG-9.1") ||
strings.HasPrefix(s, "PG-9.2") ||
strings.HasPrefix(s, "PG-9.3") ||
strings.HasPrefix(s, "PG-9.4") ||
strings.HasPrefix(s, "PG-9.5")) ||
!strings.HasSuffix(s, "/logfebe-1") {
exit("protocol version not supported: %s", s)
}
}
