window change hack in telnetd

diff --git a/commands/telnetd/telnet.c b/commands/telnetd/telnet.c
index 90794c3f131f5104c865dbf9c57df52988afc427..0bbe6552b399a839e08efedfc13bee2e9bbaa4b3 100755 (executable)
--- a/commands/telnetd/telnet.c
+++ b/commands/telnetd/telnet.c
@@ -12,24 +12,32 @@
 #include <sys/types.h>
 #include <string.h>
 #include <fcntl.h>
+#include <errno.h>
 #include <unistd.h>
+#include <termios.h>
 #include "telnetd.h"
 #include "telnet.h"
 #include <stdio.h>
+#include <sys/ioctl.h>
+
 
 #define        IN_DATA 0
 #define        IN_CR   1
 #define        IN_IAC  2
 #define        IN_IAC2 3
+#define IN_SB  4
 
 _PROTOTYPE(static void dowill, (int c));
 _PROTOTYPE(static void dowont, (int c));
 _PROTOTYPE(static void dodo, (int c));
 _PROTOTYPE(static void dodont, (int c));
 _PROTOTYPE(static void respond, (int ack, int option));
+_PROTOTYPE(static void respond_really, (int ack, int option));
 
 #define        LASTTELOPT      TELOPT_SGA
 
+static int r_winch = 0;
+
 static int TelROpts[LASTTELOPT+1];
 static int TelLOpts[LASTTELOPT+1];
 
@@ -63,7 +71,7 @@ int len;
                if(option <= LASTTELOPT) {
                        TelROpts[option] = 1;
                        len = 3;
-               }
+               } else if(option == TELOPT_WINCH && !r_winch) { r_winch = 1; len = 3; } 
                break;
        case DONT:
                if(option <= LASTTELOPT) {
@@ -88,6 +96,15 @@ int len;
        (void) write(fdout, buf, len);
 }
 
+int set_winsize(int fd, unsigned int cols, unsigned int rows)
+{
+       struct winsize w;
+       memset(&w, 0, sizeof(w));
+       w.ws_col = cols;
+       w.ws_row = rows;
+       ioctl(fd, TIOCSWINSZ, (char *) &w);
+}
+
 int tel_in(fdout, telout, buffer, len)
 int fdout;
 int telout;
@@ -134,6 +151,9 @@ int c;
                                        InState = IN_IAC2;
                                        ThisOpt = c;
                                        break;
+                               case SB:
+                                       InState = IN_SB; 
+                                       break;
                                case EOR:
                                case SE:
                                case NOP:
@@ -144,7 +164,6 @@ int c;
                                case EC:
                                case EL:
                                case GA:
-                               case SB:
                                        break;
                                default:
                                        break;
@@ -164,6 +183,43 @@ int c;
                                case DONT:      dodont(c);      break;
                        }
                        break;
+               case IN_SB:
+               {
+                       static int winchpos = -1;
+                       /* Subnegotiation. */
+                       if(winchpos >= 0) {
+                               static unsigned int winchbuf[5], iacs = 0;
+                               winchbuf[winchpos] = c;
+                               /* IAC is escaped - unescape it. */
+                               if(c == IAC) iacs++; else { iacs = 0; winchpos++; }
+                               if(iacs == 2) { winchpos++; iacs = 0; }
+                               if(winchpos >= 4) {
+                                       /* End of WINCH data. */
+                                       set_winsize(fdout,
+                                       (winchbuf[0] << 8) | winchbuf[1],
+                                       (winchbuf[2] << 8) | winchbuf[3]);
+                                       winchpos = -1;
+                               }
+                       } else {
+                               static int lastiac = 0;
+                               switch(c) {
+                                       case TELOPT_WINCH:
+                                               /* Start listening. */
+                                               winchpos = 0;
+                                               break;
+                                       case SE:
+                                               if(lastiac) InState = IN_DATA;
+                                               break;
+                                       default:
+                                               break;
+                               }
+                               if(c == IAC) lastiac = 1;
+                               else lastiac = 0;
+
+
+                       }
+                       break;
+               }
        }
    }
 
@@ -211,9 +267,16 @@ int ack;
                TelROpts[c] = 1;
                ack = DO;
                break;
+       case TELOPT_WINCH:
+               if(r_winch) return;
+               r_winch = 1;
+               ack = DO;
+               respond_really(ack, c); 
+               return;
        default:
                ack = DONT;
    }
+
    respond(ack, c);
 }
 
@@ -259,5 +322,16 @@ unsigned char c[3];
    c[0] = IAC;
    c[1] = ack;
    c[2] = option;
-   /* write(telfdout, c, 3); */
+/*   write(telfdout, c, 3); */
+}
+
+static void respond_really(ack, option)
+int ack, option;
+{
+unsigned char c[3];
+
+   c[0] = IAC;
+   c[1] = ack;
+   c[2] = option;
+   write(telfdout, c, 3); 
 }

diff --git a/commands/telnetd/telnet.h b/commands/telnetd/telnet.h
index 668b282aa40d459264b781b06f2c0a4f902fba59..893aad8257bfcf6d2f566fb400f040b285be0f9e 100755 (executable)
--- a/commands/telnetd/telnet.h
+++ b/commands/telnetd/telnet.h
@@ -61,6 +61,7 @@
 #define        TELOPT_SNDLOC   23      /* send location                        */
 #define        TELOPT_TTYPE    24      /* terminal type                        */
 #define        TELOPT_EOR      25      /* end or record                        */
+#define        TELOPT_WINCH    31      /* window size                          */
 #define TELOPT_EXOPL   255     /* extended-options-list                */
 
 /* Sub-option qualifiers. */

diff --git a/commands/telnetd/term.c b/commands/telnetd/term.c
index 446b6ee8489eb2d13b2ac5706bcc753584314082..583f03e83ebd32a6cf209869ad9c39f691551edb 100755 (executable)
--- a/commands/telnetd/term.c
+++ b/commands/telnetd/term.c
@@ -38,6 +38,7 @@ void term_init()
   telopt(1, WILL, TELOPT_BINARY);
   telopt(1, DO,   TELOPT_BINARY);
   telopt(1, WILL, TELOPT_ECHO);
+  telopt(1, DO,   TELOPT_WINCH);
 }
 
 static int io_done = 0;