It used to be that if you wanted to talk directly to a network

service, you would TELNET to it, and *some* of the TELNET client
programs were broken, and would send TELNET protocol magic
sequences to the other end, even when not talking on port 23.

Now that we have varnishadm, and where netcat is widely available,
that is simply not a problem we need to keep dead code around for
any more.

bin/varnishd/mgt/mgt_cli.c

@@ -51,7 +51,6 @@
 #include "vcli_priv.h"
 #include "vcli_serve.h"
 #include "vev.h"
-#include "vlu.h"
 #include "vrnd.h"
 #include "vss.h"
 #include "vtcp.h"
@@ -388,10 +387,6 @@ mgt_cli_setup(int fdi, int fdo, int verbose, const char *ident,
 
 	cli->ident = strdup(ident);
 
-	/* Deal with TELNET options */
-	if (fdi != 0)
-		VLU_SetTelnet(cli->vlu, fdo);
-
 	if (fdi != 0 && secret_file != NULL) {
 		cli->auth = MCF_NOAUTH;
 		mgt_cli_challenge(cli);

include/vlu.h

@@ -34,6 +34,4 @@ typedef int (vlu_f)(void *, const char *);
 struct vlu *VLU_New(void *priv, vlu_f *func, unsigned bufsize);
 int VLU_Fd(int fd, struct vlu *l);
 void VLU_Destroy(struct vlu *l);
-void VLU_SetTelnet(struct vlu *l, int fd);
-
 #endif

lib/libvarnish/vlu.c

@@ -47,7 +47,6 @@ struct vlu {
 	unsigned	bufl;
 	unsigned	bufp;
 	void		*priv;
-	int		telnet;
 	vlu_f	*func;
 };
 
@@ -63,7 +62,6 @@ VLU_New(void *priv, vlu_f *func, unsigned bufsize)
 		l->func = func;
 		l->priv = priv;
 		l->bufl = bufsize - 1;
-		l->telnet = -1;
 		l->buf = malloc(l->bufl + 1L);
 		if (l->buf == NULL) {
 			FREE_OBJ(l);
@@ -73,14 +71,6 @@ VLU_New(void *priv, vlu_f *func, unsigned bufsize)
 	return (l);
 }
 
-void
-VLU_SetTelnet(struct vlu *l, int fd)
-{
-	CHECK_OBJ_NOTNULL(l, LINEUP_MAGIC);
-	assert(fd >= 0);
-	l->telnet = fd;
-}
-
 void
 VLU_Destroy(struct vlu *l)
 {
@@ -90,52 +80,6 @@ VLU_Destroy(struct vlu *l)
 	FREE_OBJ(l);
 }
 
-static int
-vlu_dotelnet(struct vlu *l, char *p)
-{
-	char *e;
-	char tno[3];
-	int i;
-
-	e = l->buf + l->bufp;
-	assert(p >= l->buf && p < e);
-	assert(*p == (char)255);
-
-	/* We need at least two characters */
-	if (p == e - 1)
-		return (1);
-
-	/* And three for will/wont/do/dont */
-	if (p[1] >= (char)251 && p[1] <= (char)254 && p == e - 2)
-		return (1);
-
-	switch (p[1]) {
-	case (char)251:	/* WILL */
-	case (char)252:	/* WONT */
-		/* Ignore these */
-		i = 3;
-		break;
-	case (char)253:	/* DO */
-	case (char)254:	/* DONT */
-		/* Return WONT for these */
-		memcpy(tno, p, 3);
-		tno[1] = (char)252;
-		if (write(l->telnet, tno, 3) != 3)
-			return (1);
-		i = 3;
-		break;
-	default:
-		/* Ignore the rest */
-		/* XXX: only p[1] >= 240 ? */
-		i = 2;
-	}
-
-	/* Remove telnet sequence from buffer */
-	memmove(p, p + i, 1 + e - (p + i));
-	l->bufp -= i;
-	return (0);
-}
-
 static int
 LineUpProcess(struct vlu *l)
 {
@@ -146,9 +90,6 @@ LineUpProcess(struct vlu *l)
 	for (p = l->buf; *p != '\0'; p = q) {
 		/* Find first CR or NL */
 		for (q = p; *q != '\0'; q++) {
-			while (l->telnet >= 0 && *q == (char)255)
-				if (vlu_dotelnet(l, q))
-					return (0);
 			if (*q == '\n' || *q == '\r')
 				break;
 		}