"Bye-Bye Flying Horse" patch

- a robust and clean TELNET protocol implementation
- fixed hz lib (autoconvert) utf8 buffer overflow exploit
- enabled term resizing in runtime, and even AYT!
- eliminated the flying-horse delay in connecting stage


git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@2691 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

1 files changed, 71 insertions, 26 deletions

diff --git a/mbbsd/convert.c b/mbbsd/convert.c
index ff9fef5c..a7e1ff31 100644
--- a/mbbsd/convert.c
+++ b/mbbsd/convert.c
@@ -1,11 +1,8 @@
-/* $Id: convert.c 1374 2003-11-27 14:11:40Z victor $ */
+/* $Id$ */
 #include "bbs.h"
 
 #ifdef CONVERT
 
-extern read_write_type write_type;
-extern read_write_type read_type;
-
 unsigned char *gb2big(unsigned char *, int *, int);
 unsigned char *big2gb(unsigned char *, int *, int);
 unsigned char *utf8_uni(unsigned char *, int *, int);
@@ -13,56 +10,104 @@ unsigned char *uni_utf8(unsigned char *, int *, int);
 unsigned char *uni2big(unsigned char *, int *, int);
 unsigned char *big2uni(unsigned char *, int *, int);
 
-static ssize_t gb_read(int fd, void *buf, size_t count)
+static ssize_t 
+gb_input(void *buf, ssize_t icount)
+{
+    gb2big((char *)buf, &icount, 0);
+    return icount;
+}
+
+static ssize_t 
+gb_read(int fd, void *buf, size_t count)
 {
-    int      icount = (int)read(fd, buf, count);
-    if (count > 0)
-	gb2big((char *)buf, &icount, 0);
-    return (size_t)icount;
+    ssize_t icount = read(fd, buf, count);
+    if (icount > 0)
+	    icount = gb_input(buf, icount);
+    return icount;
 }
 
-static ssize_t gb_write(int fd, void *buf, size_t count)
+static ssize_t 
+gb_write(int fd, void *buf, size_t count)
 {
     int     icount = (int)count;
     big2gb((char *)buf, &icount, 0);
-    return write(fd, buf, (size_t)icount);
+    if(icount > 0)
+	return write(fd, buf, (size_t)icount);
+    else
+	return count; /* fake */
 }
 
-static ssize_t utf8_read(int fd, void *buf, size_t count)
+static ssize_t 
+utf8_input  (void *buf, ssize_t icount) 
 {
-    count = read(fd, buf, count);
-    if (count > 0) {
-	int     icount = (int)count;
-	utf8_uni(buf, &icount, 0);
-	uni2big(buf, &icount, 0);
-	((char *)buf)[icount] = 0;
-	return (size_t)icount;
-    }
-    return count;
+    utf8_uni(buf, &icount, 0);
+    uni2big(buf, &icount, 0);
+    return icount;
+}
+
+static ssize_t 
+utf8_read(int fd, void *buf, size_t count)
+{
+    ssize_t icount = read(fd, buf, count);
+    if (icount > 0)
+	    icount = utf8_input(buf, icount);
+    return icount;
 }
 
-static ssize_t utf8_write(int fd, void *buf, size_t count)
+static ssize_t 
+utf8_write(int fd, void *buf, size_t count)
 {
     int     icount = (int)count;
-    big2uni(buf, &icount, 0);
-    uni_utf8(buf, &icount, 0);
-    ((char *)buf)[icount] = 0;
-    return write(fd, buf, (size_t)icount);
+    static char *mybuf = NULL;
+    int         cmybuf = 0;
+
+    /* utf8 output is a special case because 
+     * we need larger buffer which can be 
+     * tripple or more in size.
+     * Current implementation uses 128 for each block.
+     */
+
+    if(cmybuf < count * 4) {
+	cmybuf = (count*4+0x80) & (~0x7f) ;
+	mybuf = (char*) realloc (mybuf, cmybuf);
+    }
+    memcpy(mybuf, buf, count);
+    big2uni(mybuf, &icount, 0);
+    uni_utf8(mybuf, &icount, 0);
+    if(icount > 0)
+	return write(fd, mybuf, (size_t)icount);
+    else
+	return count; /* fake */
 }
 
+static ssize_t 
+norm_input(void *buf, ssize_t icount)
+{
+    return icount;
+}
+
+/* global function pointers */
+read_write_type write_type = (read_write_type)write;
+read_write_type read_type = read;
+convert_type    input_type = norm_input;
+
 void set_converting_type(int which)
 {
     if (which == CONV_NORMAL) {
 	read_type = read;
 	write_type = (read_write_type)write;
+	/* for speed up, NULL is better.. */
+	input_type = NULL; /* norm_input; */
     }
     else if (which == CONV_GB) {
 	read_type = gb_read;
 	write_type = gb_write;
+	input_type = gb_input;
     }
     else if (which == CONV_UTF8) {
 	read_type = utf8_read;
 	write_type = utf8_write;
+	input_type = utf8_input;
     }
 }