refactor: smarter channel sleeps, better byte handling, update crypto

.golangci.yaml

@@ -112,12 +112,12 @@ issues:
       text: "package-comments"
 
 run:
-  go: '1.19'
+  go: '1.20'
   skip-dirs:
     - private
 
 output:
   uniq-by-line: false
 
 service:
-  golangci-lint-version: 1.52.x
+  golangci-lint-version: 1.54.x

channel/channel.go

@@ -17,16 +17,17 @@ const (
 	// DefaultTimeoutOpsSeconds is the default time value for operations -- 60 seconds.
 	DefaultTimeoutOpsSeconds = 60
 	// DefaultReadDelayMicroSeconds is the default value for the delay between reads of the
-	// transport -- 100 microseconds. Going very low is likely to lead to very high cpu and not
+	// transport -- 250 microseconds. Going very low is likely to lead to very high cpu and not
 	// yield any recognizable gains, so be careful changing this!
 	DefaultReadDelayMicroSeconds = 250
 	// DefaultReturnChar is the character used to send an "enter" key to the device, "\n".
 	DefaultReturnChar = "\n"
 	// DefaultPromptSearchDepth -- is the default depth to search for the prompt in the received
 	// bytes.
 	DefaultPromptSearchDepth = 1_000
-	redacted                 = "redacted"
-	readDelayDivisor         = 1_000
+
+	redacted         = "redacted"
+	readDelayDivisor = 1_000
 )
 
 var (

channel/read.go

@@ -33,9 +33,6 @@ func (c *Channel) read() {
 		// afraid to remove it!
 		b = bytes.ReplaceAll(b, []byte("\r"), []byte(""))
 
-		// trim out all the space we padded in the buffer to read into
-		b = bytes.ReplaceAll(b, []byte("\x00"), []byte(""))
-
 		if bytes.Contains(b, []byte("\x1b")) {
 			b = util.StripANSI(b)
 		}
@@ -61,6 +58,7 @@ func (c *Channel) Read() ([]byte, error) {
 	case err := <-c.Errs:
 		return nil, err
 	default:
+		time.Sleep(c.ReadDelay)
 	}
 
 	b := c.Q.Dequeue()
@@ -117,15 +115,11 @@ func (c *Channel) ReadUntilPrompt() ([]byte, error) {
 	var rb []byte
 
 	for {
-		select {
-		case err := <-c.Errs:
+		nb, err := c.Read()
+		if err != nil {
 			return nil, err
-		default:
-			time.Sleep(c.ReadDelay)
 		}
 
-		nb := c.Q.Dequeue()
-
 		if nb == nil {
 			continue
 		}
@@ -146,23 +140,21 @@ func (c *Channel) ReadUntilAnyPrompt(prompts []*regexp.Regexp) ([]byte, error) {
 	var rb []byte
 
 	for {
-		select {
-		case err := <-c.Errs:
+		nb, err := c.Read()
+		if err != nil {
 			return nil, err
-		default:
-			time.Sleep(c.ReadDelay)
 		}
 
-		nb := c.Q.Dequeue()
-
 		if nb == nil {
 			continue
 		}
 
 		rb = append(rb, nb...)
 
+		prb := c.processReadBuf(rb)
+
 		for _, p := range prompts {
-			if p.Match(rb) {
+			if p.Match(prb) {
 				c.l.Debugf("channel read %#v", string(rb))
 
 				return rb, nil
@@ -177,22 +169,18 @@ func (c *Channel) ReadUntilExplicit(b []byte) ([]byte, error) {
 	var rb []byte
 
 	for {
-		select {
-		case err := <-c.Errs:
+		nb, err := c.Read()
+		if err != nil {
 			return nil, err
-		default:
-			time.Sleep(c.ReadDelay)
 		}
 
-		nb := c.Q.Dequeue()
-
 		if nb == nil {
 			continue
 		}
 
 		rb = append(rb, nb...)
 
-		if bytes.Contains(rb, b) {
+		if bytes.Contains(c.processReadBuf(rb), b) {
 			c.l.Debugf("channel read %#v", string(rb))
 
 			return rb, nil

go.mod

@@ -6,7 +6,6 @@ require (
 	github.com/creack/pty v1.1.18
 	github.com/google/go-cmp v0.5.9
 	github.com/sirikothe/gotextfsm v1.0.1-0.20200816110946-6aa2cfd355e4
-	golang.org/x/crypto v0.6.0
-	golang.org/x/term v0.8.0 // indirect
+	golang.org/x/crypto v0.12.0
 	gopkg.in/yaml.v3 v3.0.1
 )

go.sum

@@ -7,35 +7,43 @@ github.com/sirikothe/gotextfsm v1.0.1-0.20200816110946-6aa2cfd355e4/go.mod h1:CJ
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.6.0 h1:qfktjS5LUO+fFKeJXZ+ikTRijMmljikvG68fpMMruSc=
-golang.org/x/crypto v0.6.0/go.mod h1:OFC/31mSvZgRz0V1QTNCzfAI1aIRzbiufJtkMIlEp58=
+golang.org/x/crypto v0.12.0 h1:tFM/ta59kqch6LlvYnPa0yx5a83cL2nHflFhYKvv9Yk=
+golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
 golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
+golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
-golang.org/x/term v0.8.0 h1:n5xxQn2i3PC0yLAbjTpNT85q/Kgzcr2gIoX9OrJUols=
 golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
+golang.org/x/term v0.11.0 h1:F9tnn/DA/Im8nCwm+fX+1/eBwi4qFjRT++MhtVC4ZX0=
+golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
+golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

transport/standard.go

@@ -236,9 +236,12 @@ func (t *Standard) IsAlive() bool {
 func (t *Standard) Read(n int) ([]byte, error) {
 	b := make([]byte, n)
 
-	_, err := t.reader.Read(b)
+	n, err := t.reader.Read(b)
+	if err != nil {
+		return nil, err
+	}
 
-	return b, err
+	return b[0:n], nil
 }
 
 // Write writes bytes b to the transport.

transport/system.go

@@ -216,9 +216,12 @@ func (t *System) IsAlive() bool {
 func (t *System) Read(n int) ([]byte, error) {
 	b := make([]byte, n)
 
-	_, err := t.fd.Read(b)
+	n, err := t.fd.Read(b)
+	if err != nil {
+		return nil, err
+	}
 
-	return b, err
+	return b[0:n], nil
 }
 
 // Write writes bytes b to the transport.