telnetd: correctly output 0xff char. ~100 bytes.

telnet: fix some atrocious names and style. no code changes

networking/telnet.c

@@ -93,7 +93,7 @@ static void will_charmode(void);
 static void telopt(byte c);
 static int subneg(byte c);
 
-static void iacflush(void)
+static void iac_flush(void)
 {
 	write(netfd, G.iacbuf, G.iaclen);
 	G.iaclen = 0;
@@ -108,11 +108,11 @@ static void doexit(int ev)
 	exit(ev);
 }
 
-static void conescape(void)
+static void con_escape(void)
 {
 	char b;
 
-	if (bb_got_signal)	/* came from line  mode... go raw */
+	if (bb_got_signal) /* came from line mode... go raw */
 		rawmode();
 
 	write_str(1, "\r\nConsole escape. Commands are:\r\n\n"
@@ -128,13 +128,13 @@ static void conescape(void)
 	case 'l':
 		if (!bb_got_signal) {
 			do_linemode();
-			goto rrturn;
+			goto ret;
 		}
 		break;
 	case 'c':
 		if (bb_got_signal) {
 			will_charmode();
-			goto rrturn;
+			goto ret;
 		}
 		break;
 	case 'z':
@@ -150,13 +150,12 @@ static void conescape(void)
 
 	if (bb_got_signal)
 		cookmode();
-
+ ret:
- rrturn:
 	bb_got_signal = 0;
 
 }
 
-static void handlenetoutput(int len)
+static void handle_net_output(int len)
 {
 	/* here we could do smart tricks how to handle 0xFF:s in output
 	 * stream like writing twice every sequence of FF:s (thus doing
@@ -169,19 +168,19 @@ static void handlenetoutput(int len)
 	 * first - I cannot use programs like sz/rz
 	 * second - the 0x0D is sent as one character and if the next
 	 *	char is 0x0A then it's eaten by a server side.
-	 * third - whay doy you have to make 'many write()s'?
+	 * third - why do you have to make 'many write()s'?
 	 *	I don't understand.
-	 * So I implemented it. It's realy useful for me. I hope that
+	 * So I implemented it. It's really useful for me. I hope that
-	 * others people will find it interesting too.
+	 * other people will find it interesting too.
 	 */
 
 	int i, j;
-	byte * p = (byte*)G.buf;
+	byte *p = (byte*)G.buf;
 	byte outbuf[4*DATABUFSIZE];
 
 	for (i = len, j = 0; i > 0; i--, p++) {
 		if (*p == 0x1d) {
-			conescape();
+			con_escape();
 			return;
 		}
 		outbuf[j++] = *p;
@@ -194,7 +193,7 @@ static void handlenetoutput(int len)
 		write(netfd, outbuf, j);
 }
 
-static void handlenetinput(int len)
+static void handle_net_input(int len)
 {
 	int i;
 	int cstart = 0;
@@ -207,51 +206,54 @@ static void handlenetinput(int len)
 				cstart = i;
 				G.telstate = TS_IAC;
 			}
-		} else
+			continue;
-			switch (G.telstate) {
+		}
-			case TS_0:
+		switch (G.telstate) {
-				if (c == IAC)
+		case TS_0:
-					G.telstate = TS_IAC;
+			if (c == IAC)
-				else
+				G.telstate = TS_IAC;
-					G.buf[cstart++] = c;
+			else
-				break;
+				G.buf[cstart++] = c;
+			break;
 
-			case TS_IAC:
+		case TS_IAC:
-				if (c == IAC) { /* IAC IAC -> 0xFF */
+			if (c == IAC) { /* IAC IAC -> 0xFF */
-					G.buf[cstart++] = c;
+				G.buf[cstart++] = c;
-					G.telstate = TS_0;
-					break;
-				}
-				/* else */
-				switch (c) {
-				case SB:
-					G.telstate = TS_SUB1;
-					break;
-				case DO:
-				case DONT:
-				case WILL:
-				case WONT:
-					G.telwish =  c;
-					G.telstate = TS_OPT;
-					break;
-				default:
-					G.telstate = TS_0;	/* DATA MARK must be added later */
-				}
-				break;
-			case TS_OPT: /* WILL, WONT, DO, DONT */
-				telopt(c);
 				G.telstate = TS_0;
 				break;
-			case TS_SUB1: /* Subnegotiation */
-			case TS_SUB2: /* Subnegotiation */
-				if (subneg(c))
-					G.telstate = TS_0;
-				break;
 			}
+			/* else */
+			switch (c) {
+			case SB:
+				G.telstate = TS_SUB1;
+				break;
+			case DO:
+			case DONT:
+			case WILL:
+			case WONT:
+				G.telwish =  c;
+				G.telstate = TS_OPT;
+				break;
+			default:
+				G.telstate = TS_0;	/* DATA MARK must be added later */
+			}
+			break;
+		case TS_OPT: /* WILL, WONT, DO, DONT */
+			telopt(c);
+			G.telstate = TS_0;
+			break;
+		case TS_SUB1: /* Subnegotiation */
+		case TS_SUB2: /* Subnegotiation */
+			if (subneg(c))
+				G.telstate = TS_0;
+			break;
+		}
 	}
 	if (G.telstate) {
-		if (G.iaclen) iacflush();
+		if (G.iaclen)
-		if (G.telstate == TS_0)	G.telstate = 0;
+			iac_flush();
+		if (G.telstate == TS_0)
+			G.telstate = 0;
 		len = cstart;
 	}
 
@@ -259,87 +261,87 @@ static void handlenetinput(int len)
 		write(STDOUT_FILENO, G.buf, len);
 }
 
-static void putiac(int c)
+static void put_iac(int c)
 {
 	G.iacbuf[G.iaclen++] = c;
 }
 
-static void putiac2(byte wwdd, byte c)
+static void put_iac2(byte wwdd, byte c)
 {
 	if (G.iaclen + 3 > IACBUFSIZE)
-		iacflush();
+		iac_flush();
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(wwdd);
+	put_iac(wwdd);
-	putiac(c);
+	put_iac(c);
 }
 
 #if ENABLE_FEATURE_TELNET_TTYPE
-static void putiac_subopt(byte c, char *str)
+static void put_iac_subopt(byte c, char *str)
 {
-	int	len = strlen(str) + 6;   // ( 2 + 1 + 1 + strlen + 2 )
+	int len = strlen(str) + 6;   // ( 2 + 1 + 1 + strlen + 2 )
 
 	if (G.iaclen + len > IACBUFSIZE)
-		iacflush();
+		iac_flush();
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(SB);
+	put_iac(SB);
-	putiac(c);
+	put_iac(c);
-	putiac(0);
+	put_iac(0);
 
 	while (*str)
-		putiac(*str++);
+		put_iac(*str++);
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(SE);
+	put_iac(SE);
 }
 #endif
 
 #if ENABLE_FEATURE_TELNET_AUTOLOGIN
-static void putiac_subopt_autologin(void)
+static void put_iac_subopt_autologin(void)
 {
 	int len = strlen(G.autologin) + 6;	// (2 + 1 + 1 + strlen + 2)
 	const char *user = "USER";
 
 	if (G.iaclen + len > IACBUFSIZE)
-		iacflush();
+		iac_flush();
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(SB);
+	put_iac(SB);
-	putiac(TELOPT_NEW_ENVIRON);
+	put_iac(TELOPT_NEW_ENVIRON);
-	putiac(TELQUAL_IS);
+	put_iac(TELQUAL_IS);
-	putiac(NEW_ENV_VAR);
+	put_iac(NEW_ENV_VAR);
 
 	while (*user)
-		putiac(*user++);
+		put_iac(*user++);
 
-	putiac(NEW_ENV_VALUE);
+	put_iac(NEW_ENV_VALUE);
 
 	while (*G.autologin)
-		putiac(*G.autologin++);
+		put_iac(*G.autologin++);
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(SE);
+	put_iac(SE);
 }
 #endif
 
 #if ENABLE_FEATURE_AUTOWIDTH
-static void putiac_naws(byte c, int x, int y)
+static void put_iac_naws(byte c, int x, int y)
 {
 	if (G.iaclen + 9 > IACBUFSIZE)
-		iacflush();
+		iac_flush();
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(SB);
+	put_iac(SB);
-	putiac(c);
+	put_iac(c);
 
-	putiac((x >> 8) & 0xff);
+	put_iac((x >> 8) & 0xff);
-	putiac(x & 0xff);
+	put_iac(x & 0xff);
-	putiac((y >> 8) & 0xff);
+	put_iac((y >> 8) & 0xff);
-	putiac(y & 0xff);
+	put_iac(y & 0xff);
 
-	putiac(IAC);
+	put_iac(IAC);
-	putiac(SE);
+	put_iac(SE);
 }
 #endif
 
@@ -368,9 +370,9 @@ static void will_charmode(void)
 	G.telflags |= (UF_ECHO | UF_SGA);
 	setConMode();
 
-	putiac2(DO, TELOPT_ECHO);
+	put_iac2(DO, TELOPT_ECHO);
-	putiac2(DO, TELOPT_SGA);
+	put_iac2(DO, TELOPT_SGA);
-	iacflush();
+	iac_flush();
 }
 
 static void do_linemode(void)
@@ -379,24 +381,24 @@ static void do_linemode(void)
 	G.telflags &= ~(UF_ECHO | UF_SGA);
 	setConMode();
 
-	putiac2(DONT, TELOPT_ECHO);
+	put_iac2(DONT, TELOPT_ECHO);
-	putiac2(DONT, TELOPT_SGA);
+	put_iac2(DONT, TELOPT_SGA);
-	iacflush();
+	iac_flush();
 }
 
 static void to_notsup(char c)
 {
 	if (G.telwish == WILL)
-		putiac2(DONT, c);
+		put_iac2(DONT, c);
 	else if (G.telwish == DO)
-		putiac2(WONT, c);
+		put_iac2(WONT, c);
 }
 
 static void to_echo(void)
 {
 	/* if server requests ECHO, don't agree */
 	if (G.telwish == DO) {
-		putiac2(WONT, TELOPT_ECHO);
+		put_iac2(WONT, TELOPT_ECHO);
 		return;
 	}
 	if (G.telwish == DONT)
@@ -412,9 +414,9 @@ static void to_echo(void)
 		G.telflags ^= UF_ECHO;
 
 	if (G.telflags & UF_ECHO)
-		putiac2(DO, TELOPT_ECHO);
+		put_iac2(DO, TELOPT_ECHO);
 	else
-		putiac2(DONT, TELOPT_ECHO);
+		put_iac2(DONT, TELOPT_ECHO);
 
 	setConMode();
 	write_str(1, "\r\n");  /* sudden modec */
@@ -432,9 +434,9 @@ static void to_sga(void)
 
 	G.telflags ^= UF_SGA; /* toggle */
 	if (G.telflags & UF_SGA)
-		putiac2(DO, TELOPT_SGA);
+		put_iac2(DO, TELOPT_SGA);
 	else
-		putiac2(DONT, TELOPT_SGA);
+		put_iac2(DONT, TELOPT_SGA);
 }
 
 #if ENABLE_FEATURE_TELNET_TTYPE
@@ -443,9 +445,9 @@ static void to_ttype(void)
 	/* Tell server we will (or won't) do TTYPE */
 
 	if (G.ttype)
-		putiac2(WILL, TELOPT_TTYPE);
+		put_iac2(WILL, TELOPT_TTYPE);
 	else
-		putiac2(WONT, TELOPT_TTYPE);
+		put_iac2(WONT, TELOPT_TTYPE);
 }
 #endif
 
@@ -455,9 +457,9 @@ static void to_new_environ(void)
 	/* Tell server we will (or will not) do AUTOLOGIN */
 
 	if (G.autologin)
-		putiac2(WILL, TELOPT_NEW_ENVIRON);
+		put_iac2(WILL, TELOPT_NEW_ENVIRON);
 	else
-		putiac2(WONT, TELOPT_NEW_ENVIRON);
+		put_iac2(WONT, TELOPT_NEW_ENVIRON);
 }
 #endif
 
@@ -465,7 +467,7 @@ static void to_new_environ(void)
 static void to_naws(void)
 {
 	/* Tell server we will do NAWS */
-	putiac2(WILL, TELOPT_NAWS);
+	put_iac2(WILL, TELOPT_NAWS);
 }
 #endif
 
@@ -487,7 +489,7 @@ static void telopt(byte c)
 #if ENABLE_FEATURE_AUTOWIDTH
 	case TELOPT_NAWS:
 		to_naws();
-		putiac_naws(c, G.win_width, G.win_height);
+		put_iac_naws(c, G.win_width, G.win_height);
 		break;
 #endif
 	default:
@@ -506,12 +508,12 @@ static int subneg(byte c)
 #if ENABLE_FEATURE_TELNET_TTYPE
 		else
 		if (c == TELOPT_TTYPE)
-			putiac_subopt(TELOPT_TTYPE, G.ttype);
+			put_iac_subopt(TELOPT_TTYPE, G.ttype);
 #endif
 #if ENABLE_FEATURE_TELNET_AUTOLOGIN
 		else
 		if (c == TELOPT_NEW_ENVIRON)
-			putiac_subopt_autologin();
+			put_iac_subopt_autologin();
 #endif
 		break;
 	case TS_SUB2:
@@ -611,7 +613,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
 		case -1:
 			/* error, ignore and/or log something, bay go to loop */
 			if (bb_got_signal)
-				conescape();
+				con_escape();
 			else
 				sleep(1);
 			break;
@@ -627,7 +629,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
 				if (len <= 0)
 					doexit(EXIT_SUCCESS);
 				TRACE(0, ("Read con: %d\n", len));
-				handlenetoutput(len);
+				handle_net_output(len);
 			}
 
 #ifdef USE_POLL
@@ -642,7 +644,7 @@ int telnet_main(int argc UNUSED_PARAM, char **argv)
 					doexit(EXIT_FAILURE);
 				}
 				TRACE(0, ("Read netfd (%d): %d\n", netfd, len));
-				handlenetinput(len);
+				handle_net_input(len);
 			}
 		}
 	} /* while (1) */

networking/telnetd.c

@@ -74,9 +74,6 @@ static const char *issuefile = "/etc/issue.net";
    past (bf + len) then that IAC will be left unprocessed and *processed
    will be less than len.
 
-   FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
-   what is the escape character?  We aren't handling that situation here.
-
    CR-LF ->'s CR mapping is also done here, for convenience.
 
    NB: may fail to remove iacs which wrap around buffer!
@@ -159,6 +156,47 @@ remove_iacs(struct tsession *ts, int *pnum_totty)
 	return memmove(ptr - num_totty, ptr0, num_totty);
 }
 
+/*
+ * Converting single 0xff into double on output
+ */
+static size_t iac_safe_write(int fd, const char *buf, size_t count)
+{
+	const char *oxff;
+	size_t wr, rc, total;
+
+	total = 0;
+	while (1) {
+		if (count == 0)
+			return total;
+		if (*buf == (char)0xff) {
+			rc = safe_write(fd, "\xff\xff", 2);
+			if (rc != 2)
+				break;
+			buf++;
+			total++;
+			count--;
+			continue;
+		}
+		/* count != 0, *buf != 0xff */
+		oxff = memchr(buf, 0xff, count);
+		wr = count;
+		if (oxff)
+			wr = oxff - buf;
+		rc = safe_write(fd, buf, wr);
+		if (rc != wr)
+			break;
+		buf += rc;
+		total += rc;
+		count -= rc;
+	}
+	/* here: rc - result of last short write */
+	if ((ssize_t)rc < 0) { /* error? */
+		if (total == 0)
+			return rc;
+		rc = 0;
+	}
+	return total + rc;
+}
 
 static struct tsession *
 make_new_session(
@@ -212,9 +250,15 @@ make_new_session(
 			IAC, WILL, TELOPT_ECHO,
 			IAC, WILL, TELOPT_SGA
 		};
-		memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send));
+		/* This confuses iac_safe_write(), it will try to duplicate
-		ts->rdidx2 = sizeof(iacs_to_send);
+		 * each IAC... */
-		ts->size2 = sizeof(iacs_to_send);
+		//memcpy(TS_BUF2, iacs_to_send, sizeof(iacs_to_send));
+		//ts->rdidx2 = sizeof(iacs_to_send);
+		//ts->size2 = sizeof(iacs_to_send);
+		/* So just stuff it into TCP buffer! */
+		safe_write(sock, iacs_to_send, sizeof(iacs_to_send));
+		/*ts->rdidx2 = 0; - xzalloc did it! */
+		/*ts->size2 = 0;*/
 	}
 
 	fflush(NULL); /* flush all streams */
@@ -538,7 +582,7 @@ int telnetd_main(int argc UNUSED_PARAM, char **argv)
 		if (/*ts->size2 &&*/ FD_ISSET(ts->sockfd_write, &wrfdset)) {
 			/* Write to socket from buffer 2. */
 			count = MIN(BUFSIZE - ts->wridx2, ts->size2);
-			count = safe_write(ts->sockfd_write, TS_BUF2 + ts->wridx2, count);
+			count = iac_safe_write(ts->sockfd_write, (void*)(TS_BUF2 + ts->wridx2), count);
 			if (count < 0) {
 				if (errno == EAGAIN)
 					goto skip2;