diff --git a/conncheck.go b/conncheck.go
index 0ea721720..35ff1eac6 100644
--- a/conncheck.go
+++ b/conncheck.go
@@ -12,17 +12,14 @@
package mysql
import (
- "errors"
- "io"
+ "fmt"
"net"
"syscall"
-)
-var errUnexpectedRead = errors.New("unexpected read from socket")
+ "golang.org/x/sys/unix"
+)
func connCheck(conn net.Conn) error {
- var sysErr error
-
sysConn, ok := conn.(syscall.Conn)
if !ok {
return nil
@@ -32,24 +29,22 @@ func connCheck(conn net.Conn) error {
return err
}
- err = rawConn.Read(func(fd uintptr) bool {
- var buf [1]byte
- n, err := syscall.Read(int(fd), buf[:])
- switch {
- case n == 0 && err == nil:
- sysErr = io.EOF
- case n > 0:
- sysErr = errUnexpectedRead
- case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
- sysErr = nil
- default:
- sysErr = err
+ var pollErr error
+ err = rawConn.Control(func(fd uintptr) {
+ fds := []unix.PollFd{
+ {Fd: int32(fd), Events: unix.POLLIN | unix.POLLERR},
+ }
+ n, err := unix.Poll(fds, 0)
+ if err != nil {
+ pollErr = fmt.Errorf("poll: %w", err)
+ }
+ if n > 0 {
+ // fmt.Errorf("poll: %v", fds[0].Revents)
+ pollErr = errUnexpectedEvent
}
- return true
})
if err != nil {
return err
}
-
- return sysErr
+ return pollErr
}
diff --git a/go.mod b/go.mod
index 77bbb8dbf..2d95971d5 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
module github.com/go-sql-driver/mysql
go 1.18
+
+require golang.org/x/sys v0.10.0 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 000000000..55a3ff26d
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
+golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
diff --git a/packets.go b/packets.go
index 66635c55b..ad757a346 100644
--- a/packets.go
+++ b/packets.go
@@ -14,6 +14,7 @@ import (
"database/sql/driver"
"encoding/binary"
"encoding/json"
+ "errors"
"fmt"
"io"
"math"
@@ -44,12 +45,24 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
// check packet sync [8 bit]
if data[3] != mc.sequence {
+ var syncErr error
if data[3] > mc.sequence {
- return nil, ErrPktSyncMul
+ syncErr = ErrPktSyncMul
+ } else {
+ syncErr = ErrPktSync
}
- return nil, ErrPktSync
+
+ if prevData != nil {
+ return nil, syncErr
+ } else {
+ // log and ignore seqno mismatch error.
+ // MySQL sometimes sends wrong sequence no.
+ mc.cfg.Logger.Print(syncErr)
+ mc.sequence = data[3] + 1
+ }
+ } else {
+ mc.sequence++
}
- mc.sequence++
// packets with length 0 terminate a previous packet which is a
// multiple of (2^24)-1 bytes long
@@ -89,6 +102,9 @@ func (mc *mysqlConn) readPacket() ([]byte, error) {
}
}
+// used in conncheck.go
+var errUnexpectedEvent = errors.New("recieved unexpected event")
+
// Write packet buffer 'data'
func (mc *mysqlConn) writePacket(data []byte) error {
pktLen := len(data) - 4
@@ -111,18 +127,29 @@ func (mc *mysqlConn) writePacket(data []byte) error {
}
var err error
if mc.cfg.CheckConnLiveness {
- if mc.cfg.ReadTimeout != 0 {
- err = conn.SetReadDeadline(time.Now().Add(mc.cfg.ReadTimeout))
- }
- if err == nil {
- err = connCheck(conn)
+ err = connCheck(conn)
+ if err != nil {
+ if err == errUnexpectedEvent {
+ _ = conn.SetReadDeadline(time.Now().Add(time.Second))
+ var data []byte
+ data, err = mc.readPacket()
+
+ if err == nil {
+ if data[0] == iERR {
+ err = mc.handleErrorPacket(data)
+ } else {
+ err = fmt.Errorf("unexpected packet: % x", data[:128])
+ }
+ } else {
+ err = fmt.Errorf("readPacket(): %w", err)
+ }
+ }
+
+ mc.cfg.Logger.Print("checkConn() failed: ", err)
+ mc.Close()
+ return driver.ErrBadConn
}
}
- if err != nil {
- mc.cfg.Logger.Print("closing bad idle connection: ", err)
- mc.Close()
- return driver.ErrBadConn
- }
}
for {
diff --git a/packets_test.go b/packets_test.go
index f429087e9..5a6882fcc 100644
--- a/packets_test.go
+++ b/packets_test.go
@@ -11,6 +11,7 @@ package mysql
import (
"bytes"
"errors"
+ "fmt"
"net"
"testing"
"time"
@@ -132,31 +133,57 @@ func TestReadPacketSingleByte(t *testing.T) {
}
}
+type mockLogger struct {
+ bytes.Buffer
+}
+
+func (ml *mockLogger) Print(v ...any) {
+ ml.WriteString(fmt.Sprint(v...) + "\n")
+}
+
func TestReadPacketWrongSequenceID(t *testing.T) {
conn := new(mockConn)
mc := &mysqlConn{
buf: newBuffer(conn),
+ cfg: NewConfig(),
}
+ logger := &mockLogger{}
+ mc.cfg.Logger = Logger(logger)
// too low sequence id
conn.data = []byte{0x01, 0x00, 0x00, 0x00, 0xff}
conn.maxReads = 1
mc.sequence = 1
- _, err := mc.readPacket()
- if err != ErrPktSync {
- t.Errorf("expected ErrPktSync, got %v", err)
+ data, err := mc.readPacket()
+ if err != nil {
+ t.Errorf("expected nil, got %v", err)
+ }
+ if len(data) != 1 || data[0] != 0xff {
+ t.Errorf("expected [0xff], got % x", data)
+ }
+ logMsg := logger.String()
+ if logMsg != ErrPktSync.Error()+"\n" {
+ t.Errorf("expected ErrPktSync.Error(), got %q", logMsg)
}
// reset
conn.reads = 0
mc.sequence = 0
mc.buf = newBuffer(conn)
+ logger.Reset()
// too high sequence id
conn.data = []byte{0x01, 0x00, 0x00, 0x42, 0xff}
- _, err = mc.readPacket()
- if err != ErrPktSyncMul {
- t.Errorf("expected ErrPktSyncMul, got %v", err)
+ data, err = mc.readPacket()
+ if err != nil {
+ t.Errorf("expected nil, got %v", err)
+ }
+ if len(data) != 1 || data[0] != 0xff {
+ t.Errorf("expected [0xff], got % x", data)
+ }
+ logMsg = logger.String()
+ if logMsg != ErrPktSyncMul.Error()+"\n" {
+ t.Errorf("expected ErrPktSync.Error(), got %q", logMsg)
}
}