ifupdown: simple code shrink

[oweals/busybox.git] / networking / telnet.c

diff --git a/networking/telnet.c b/networking/telnet.c
index 1f0d85107ed096ce2c93a4ad3ffe8f3c55546edc..58a691916e37454a60b58c463c3d522c0726d3a1 100644 (file)
--- a/networking/telnet.c
+++ b/networking/telnet.c
@@ -26,7 +26,6 @@
 //usage:       "[-a] [-l USER] HOST [PORT]"
 //usage:#define telnet_full_usage "\n\n"
 //usage:       "Connect to telnet server\n"
-//usage:     "\nOptions:"
 //usage:     "\n       -a      Automatic login with $USER variable"
 //usage:     "\n       -l USER Automatic login as USER"
 //usage:
@@ -41,10 +40,25 @@
 #include <netinet/in.h>
 #include "libbb.h"
 
+#ifdef __BIONIC__
+/* should be in arpa/telnet.h */
+# define IAC         255  /* interpret as command: */
+# define DONT        254  /* you are not to use option */
+# define DO          253  /* please, you use option */
+# define WONT        252  /* I won't use option */
+# define WILL        251  /* I will use option */
+# define SB          250  /* interpret as subnegotiation */
+# define SE          240  /* end sub negotiation */
+# define TELOPT_ECHO   1  /* echo */
+# define TELOPT_SGA    3  /* suppress go ahead */
+# define TELOPT_TTYPE 24  /* terminal type */
+# define TELOPT_NAWS  31  /* window size */
+#endif
+
 #ifdef DOTRACE
-#define TRACE(x, y) do { if (x) printf y; } while (0)
+# define TRACE(x, y) do { if (x) printf y; } while (0)
 #else
-#define TRACE(x, y)
+# define TRACE(x, y)
 #endif
 
 enum {
@@ -172,40 +186,35 @@ static void con_escape(void)
 
 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
-        * many write()s. But I think interactive telnet application does
-        * not need to be 100% 8-bit clean, so changing every 0xff:s to
-        * 0x7f:s
-        *
-        * 2002-mar-21, Przemyslaw Czerpak (druzus@polbox.com)
-        * I don't agree.
-        * 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 - why do you have to make 'many write()s'?
-        *      I don't understand.
-        * So I implemented it. It's really useful for me. I hope that
-        * other people will find it interesting too.
-        */
        byte outbuf[2 * DATABUFSIZE];
-       byte *p = (byte*)G.buf;
-       int j = 0;
+       byte *dst = outbuf;
+       byte *src = (byte*)G.buf;
+       byte *end = src + len;
 
-       for (; len > 0; len--, p++) {
-               byte c = *p;
+       while (src < end) {
+               byte c = *src++;
                if (c == 0x1d) {
                        con_escape();
                        return;
                }
-               outbuf[j++] = c;
+               *dst = c;
                if (c == IAC)
-                       outbuf[j++] = c; /* IAC -> IAC IAC */
-               else if (c == '\r')
-                       outbuf[j++] = '\0'; /* CR -> CR NUL */
+                       *++dst = c; /* IAC -> IAC IAC */
+               else
+               if (c == '\r' || c == '\n') {
+                       /* Enter key sends '\r' in raw mode and '\n' in cooked one.
+                        *
+                        * See RFC 1123 3.3.1 Telnet End-of-Line Convention.
+                        * Using CR LF instead of other allowed possibilities
+                        * like CR NUL - easier to talk to HTTP/SMTP servers.
+                        */
+                       *dst = '\r'; /* Enter -> CR LF */
+                       *++dst = '\n';
+               }
+               dst++;
        }
-       if (j > 0)
-               full_write(netfd, outbuf, j);
+       if (dst - outbuf != 0)
+               full_write(netfd, outbuf, dst - outbuf);
 }
 
 static void handle_net_input(int len)
@@ -384,20 +393,20 @@ static void put_iac_naws(byte c, int x, int y)
 }
 #endif
 
-static char const escapecharis[] ALIGN1 = "\r\nEscape character is ";
-
 static void setConMode(void)
 {
        if (G.telflags & UF_ECHO) {
                if (G.charmode == CHM_TRY) {
                        G.charmode = CHM_ON;
-                       printf("\r\nEntering character mode%s'^]'.\r\n", escapecharis);
+                       printf("\r\nEntering %s mode"
+                               "\r\nEscape character is '^%c'.\r\n", "character", ']');
                        rawmode();
                }
        } else {
                if (G.charmode != CHM_OFF) {
                        G.charmode = CHM_OFF;
-                       printf("\r\nEntering line mode%s'^C'.\r\n", escapecharis);
+                       printf("\r\nEntering %s mode"
+                               "\r\nEscape character is '^%c'.\r\n", "line", 'C');
                        cookmode();
                }
        }