Support for custom connection attributes

AUTHORS

@@ -15,6 +15,7 @@ Aaron Hopkins <go-sql-driver at die.net>
 Arne Hormann <arnehormann at gmail.com>
 Carlos Nieto <jose.carlos at menteslibres.net>
 Chris Moos <chris at tech9computers.com>
+Daniël van Eeden <daniel.van.eeden at myname.nl>
 DisposaBoy <disposaboy at dby.me>
 Frederick Mayle <frederickmayle at gmail.com>
 Gustavo Kristic <gkristic at gmail.com>

README.md

@@ -157,6 +157,16 @@ Sets the collation used for client-server interaction on connection. In contrast
 
 A list of valid charsets for a server is retrievable with `SHOW COLLATION`.
 
+##### `connattrs`
+
+```
+Type:           comma seperated string of name/value pairs
+Valid Values:   (<name1>=<value1>,<name2>=<value2>,...)
+Default:        none
+```
+
+Sends custom connection attributes to the server.
+
 ##### `clientFoundRows`
 
 ```

connection.go

@@ -49,6 +49,7 @@ type config struct {
 	clientFoundRows   bool
 	columnsWithAlias  bool
 	interpolateParams bool
+	connattrs         map[string]string
 }
 
 // Handles parameters set in DSN after the connection is established

packets.go

@@ -16,6 +16,10 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"os"
+	"path"
+	"runtime"
+	"strconv"
 	"time"
 )
 
@@ -214,6 +218,7 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 		clientLongPassword |
 		clientTransactions |
 		clientLocalFiles |
+		clientConnectAttrs |
 		mc.flags&clientLongFlag
 
 	if mc.cfg.clientFoundRows {
@@ -228,7 +233,25 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 	// User Password
 	scrambleBuff := scramblePassword(cipher, []byte(mc.cfg.passwd))
 
+	attrs := make(map[string]string)
+	attrs["_os"] = runtime.GOOS
+	attrs["_client_name"] = "Go MySQL Driver"
+	attrs["_pid"] = strconv.Itoa(os.Getpid())
+	attrs["_platform"] = runtime.GOARCH
+	attrs["program_name"] = path.Base(os.Args[0])
+	for cfganame, cfgaval := range mc.cfg.connattrs {
+		attrs[cfganame] = cfgaval
+	}
+
+	attrlen := 0
+	for attrname, attrvalue := range attrs {
+		attrlen += len(attrname) + len(attrvalue)
+		// one byte to store attrname length and one byte to store attrvalue length
+		attrlen += 2
+	}
+
 	pktLen := 4 + 4 + 1 + 23 + len(mc.cfg.user) + 1 + 1 + len(scrambleBuff)
+	pktLen += attrlen + 1 // one byte to store the total length of attrs
 
 	// To specify a db name
 	if n := len(mc.cfg.dbname); n > 0 {
@@ -295,6 +318,19 @@ func (mc *mysqlConn) writeAuthPacket(cipher []byte) error {
 		pos += copy(data[pos:], mc.cfg.dbname)
 		data[pos] = 0x00
 	}
+	pos++
+
+	// Connection attributes
+	data[pos] = byte(attrlen)
+	pos++
+
+	for attrname, attrvalue := range attrs {
+		data[pos] = byte(len(attrname))
+		pos += 1 + copy(data[pos+1:], attrname)
+
+		data[pos] = byte(len(attrvalue))
+		pos += 1 + copy(data[pos+1:], attrvalue)
+	}
 
 	// Send Auth packet
 	return mc.writePacket(data)

utils.go

@@ -277,6 +277,17 @@ func parseDSNParams(cfg *config, params string) (err error) {
 					return fmt.Errorf("Invalid value / unknown config name: %s", value)
 				}
 			}
+		case "connattrs":
+			if cfg.connattrs == nil {
+				cfg.connattrs = make(map[string]string)
+			}
+			for _, conn_v := range strings.Split(strings.TrimSuffix(strings.TrimPrefix(value, "("),")"), ",") {
+				attr := strings.SplitN(conn_v, "=", 2)
+				if len(attr) != 2 {
+					return fmt.Errorf("Invalid connection attribute: %s", conn_v)
+				}
+				cfg.connattrs[attr[0]] = attr[1]
+			}
 
 		default:
 			// lazy init

utils_test.go

@@ -22,19 +22,20 @@ var testDSNs = []struct {
 	out string
 	loc *time.Location
 }{
-	{"username:password@protocol(address)/dbname?param=value", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"username:password@protocol(address)/dbname?param=value&columnsWithAlias=true", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:true interpolateParams:false}", time.UTC},
-	{"user@unix(/path/to/socket)/dbname?charset=utf8", "&{user:user passwd: net:unix addr:/path/to/socket dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:password@tcp(localhost:5555)/dbname?charset=utf8&tls=true", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:password@tcp(localhost:5555)/dbname?charset=utf8mb4,utf8&tls=skip-verify", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8mb4,utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:password@/dbname?loc=UTC&timeout=30s&allowAllFiles=1&clientFoundRows=true&allowOldPasswords=TRUE&collation=utf8mb4_unicode_ci", "&{user:user passwd:password net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:30000000000 collation:224 allowAllFiles:true allowOldPasswords:true clientFoundRows:true columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:p@ss(word)@tcp([de:ad:be:ef::ca:fe]:80)/dbname?loc=Local", "&{user:user passwd:p@ss(word) net:tcp addr:[de:ad:be:ef::ca:fe]:80 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.Local},
-	{"/dbname", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"@/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"user:p@/ssword@/", "&{user:user passwd:p@/ssword net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
-	{"unix/?arg=%2Fsome%2Fpath.ext", "&{user: passwd: net:unix addr:/tmp/mysql.sock dbname: params:map[arg:/some/path.ext] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false}", time.UTC},
+	{"username:password@protocol(address)/dbname?param=value", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"username:password@protocol(address)/dbname?param=value&connattrs=(c1=v1)", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[c1:v1]}", time.UTC},
+	{"username:password@protocol(address)/dbname?param=value&columnsWithAlias=true", "&{user:username passwd:password net:protocol addr:address dbname:dbname params:map[param:value] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:true interpolateParams:false connattrs:map[]}", time.UTC},
+	{"user@unix(/path/to/socket)/dbname?charset=utf8", "&{user:user passwd: net:unix addr:/path/to/socket dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"user:password@tcp(localhost:5555)/dbname?charset=utf8&tls=true", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"user:password@tcp(localhost:5555)/dbname?charset=utf8mb4,utf8&tls=skip-verify", "&{user:user passwd:password net:tcp addr:localhost:5555 dbname:dbname params:map[charset:utf8mb4,utf8] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"user:password@/dbname?loc=UTC&timeout=30s&allowAllFiles=1&clientFoundRows=true&allowOldPasswords=TRUE&collation=utf8mb4_unicode_ci", "&{user:user passwd:password net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:30000000000 collation:224 allowAllFiles:true allowOldPasswords:true clientFoundRows:true columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"user:p@ss(word)@tcp([de:ad:be:ef::ca:fe]:80)/dbname?loc=Local", "&{user:user passwd:p@ss(word) net:tcp addr:[de:ad:be:ef::ca:fe]:80 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.Local},
+	{"/dbname", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname:dbname params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"@/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"/", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"", "&{user: passwd: net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"user:p@/ssword@/", "&{user:user passwd:p@/ssword net:tcp addr:127.0.0.1:3306 dbname: params:map[] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
+	{"unix/?arg=%2Fsome%2Fpath.ext", "&{user: passwd: net:unix addr:/tmp/mysql.sock dbname: params:map[arg:/some/path.ext] loc:%p tls:<nil> timeout:0 collation:33 allowAllFiles:false allowOldPasswords:false clientFoundRows:false columnsWithAlias:false interpolateParams:false connattrs:map[]}", time.UTC},
 }
 
 func TestDSNParser(t *testing.T) {