quakeforge/libs/util/msg.c
Bill Currie 31dd419fde [util] Reject non-shortest encoded utf-8 sequences
While chatting about utf-8, I noticed that QF doesn't ensure the input
sequences are the shortest possible encodings. It turns out that the
check is easy in that only the second byte needs to be checked if the
first byte's data bits are 0, and the second byte must have a data value
larger than that representable by the next lower leading byte.
2022-10-15 22:54:24 +09:00

591 lines
12 KiB
C

/*
msg.c
(description)
Copyright (C) 1996-1997 Id Software, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include "QF/msg.h"
#include "QF/qendian.h"
#include "QF/sys.h"
#include "compat.h"
/*
MESSAGE IO FUNCTIONS
Handles byte ordering and avoids alignment errors
*/
// writing functions ==========================================================
VISIBLE void
MSG_WriteByte (sizebuf_t *sb, int c)
{
byte *buf;
buf = SZ_GetSpace (sb, 1);
*buf = c;
}
VISIBLE void
MSG_WriteShort (sizebuf_t *sb, int c)
{
byte *buf;
buf = SZ_GetSpace (sb, 2);
*buf++ = ((unsigned int) c) & 0xff;
*buf = ((unsigned int) c) >> 8;
}
VISIBLE void
MSG_WriteShortBE (sizebuf_t *sb, int c)
{
byte *buf;
buf = SZ_GetSpace (sb, 2);
*buf++ = ((unsigned int) c) >> 8;
*buf = ((unsigned int) c) & 0xff;
}
VISIBLE void
MSG_WriteLong (sizebuf_t *sb, int c)
{
byte *buf;
buf = SZ_GetSpace (sb, 4);
*buf++ = ((unsigned int) c) & 0xff;
*buf++ = (((unsigned int) c) >> 8) & 0xff;
*buf++ = (((unsigned int) c) >> 16) & 0xff;
*buf = ((unsigned int) c) >> 24;
}
VISIBLE void
MSG_WriteLongBE (sizebuf_t *sb, int c)
{
byte *buf;
buf = SZ_GetSpace (sb, 4);
*buf++ = ((unsigned int) c) >> 24;
*buf++ = (((unsigned int) c) >> 16) & 0xff;
*buf++ = (((unsigned int) c) >> 8) & 0xff;
*buf = ((unsigned int) c) & 0xff;
}
VISIBLE void
MSG_WriteFloat (sizebuf_t *sb, float f)
{
union {
float f;
unsigned int l;
} dat;
dat.f = f;
dat.l = LittleLong (dat.l);
SZ_Write (sb, &dat.l, 4);
}
VISIBLE void
MSG_WriteString (sizebuf_t *sb, const char *s)
{
if (!s)
SZ_Write (sb, "", 1);
else
SZ_Write (sb, s, strlen (s) + 1);
}
VISIBLE void
MSG_WriteBytes (sizebuf_t *sb, const void *buf, unsigned len)
{
SZ_Write (sb, buf, len);
}
VISIBLE void
MSG_WriteCoord (sizebuf_t *sb, float coord)
{
MSG_WriteShort (sb, (int) (coord * 8.0));
}
VISIBLE void
MSG_WriteCoordV (sizebuf_t *sb, const vec3_t coord)
{
byte *buf;
unsigned int i, j;
buf = SZ_GetSpace (sb, 6);
for (i = 0; i < 3; i++) {
j = (int) (coord[i] * 8.0);
*buf++ = j & 0xff;
*buf++ = j >> 8;
}
}
VISIBLE void
MSG_WriteCoordAngleV (sizebuf_t *sb, const vec3_t coord, const vec3_t angles)
{
byte *buf;
int i, j;
buf = SZ_GetSpace (sb, 9);
for (i = 0; i < 3; i++) {
j = (int) (coord[i] * 8.0);
*buf++ = j & 0xff;
*buf++ = j >> 8;
*buf++ = ((int) (angles[i] * (256.0 / 360.0)) & 255);
}
}
VISIBLE void
MSG_WriteAngle (sizebuf_t *sb, float angle)
{
MSG_WriteByte (sb, (int) (angle * (256.0 / 360.0)) & 255);
}
VISIBLE void
MSG_WriteAngleV (sizebuf_t *sb, const vec3_t angles)
{
byte *buf;
int i;
buf = SZ_GetSpace (sb, 3);
for (i = 0; i < 3; i++) {
*buf++ = ((int) (angles[i] * (256.0 / 360.0)) & 255);
}
}
VISIBLE void
MSG_WriteAngle16 (sizebuf_t *sb, float angle)
{
MSG_WriteShort (sb, (int) (angle * (65536.0 / 360.0)) & 65535);
}
VISIBLE void
MSG_WriteAngle16V (sizebuf_t *sb, const vec3_t angles)
{
byte *buf;
int i;
unsigned short ang;
buf = SZ_GetSpace (sb, 6);
for (i = 0; i < 3; i++) {
ang = (int) (angles[i] * (65536.0 / 360.0)) & 65535;
*buf++ = ang & 0xff;
*buf++ = ang >> 8;
}
}
VISIBLE void
MSG_WriteUTF8 (sizebuf_t *sb, unsigned utf8)
{
byte *buf;
int count;
if (utf8 & 0x80000000) {
return; // invalid (FIXME die?)
} else if (utf8 & 0x7c000000) {
buf = SZ_GetSpace (sb, count = 6);
*buf++ = 0xfc | ((utf8 & 0x40000000) >> 30); // 1 bit
utf8 <<= 2;
} else if (utf8 & 0x03e00000) {
buf = SZ_GetSpace (sb, count = 5);
*buf++ = 0xf8 | ((utf8 & 0x03000000) >> 24); // 2 bits
utf8 <<= 8;
} else if (utf8 & 0x001f0000) {
buf = SZ_GetSpace (sb, count = 4);
*buf++ = 0xf0 | ((utf8 & 0x001c0000) >> 18); // 3 bits
utf8 <<= 14;
} else if (utf8 & 0x0000f800) {
buf = SZ_GetSpace (sb, count = 3);
*buf++ = 0xe0 | ((utf8 & 0x0000f000) >> 12); // 4 bits
utf8 <<= 20;
} else if (utf8 & 0x00000780) {
buf = SZ_GetSpace (sb, count = 2);
*buf++ = 0xc0 | ((utf8 & 0x000007c0) >> 6); // 5 bits
utf8 <<= 26;
} else {
buf = SZ_GetSpace (sb, count = 1);
*buf++ = utf8;
return;
}
while (--count) {
*buf++ = 0x80 | ((utf8 & 0xfc000000) >> 26);
utf8 <<= 6;
}
}
VISIBLE void
MSG_PokeShort (sizebuf_t *sb, unsigned offset, int c)
{
if (__builtin_expect (offset + 2 > sb->cursize, 0)) {
Sys_Error ("MSG_PokeShort: invalid offset %d / %d",
offset, sb->cursize);
}
byte *buf = sb->data + offset;
*buf++ = ((unsigned int) c) & 0xff;
*buf = ((unsigned int) c) >> 8;
}
VISIBLE void
MSG_PokeShortBE (sizebuf_t *sb, unsigned offset, int c)
{
if (__builtin_expect (offset + 2 > sb->cursize, 0)) {
Sys_Error ("MSG_PokeShortBE: invalid offset %d / %d",
offset, sb->cursize);
}
byte *buf = sb->data + offset;
*buf++ = ((unsigned int) c) >> 8;
*buf = ((unsigned int) c) & 0xff;
}
VISIBLE void
MSG_PokeLong (sizebuf_t *sb, unsigned offset, int c)
{
if (__builtin_expect (offset + 2 > sb->cursize, 0)) {
Sys_Error ("MSG_PokeLong: invalid offset %d / %d",
offset, sb->cursize);
}
byte *buf = sb->data + offset;
*buf++ = ((unsigned int) c) & 0xff;
*buf++ = (((unsigned int) c) >> 8) & 0xff;
*buf++ = (((unsigned int) c) >> 16) & 0xff;
*buf = ((unsigned int) c) >> 24;
}
VISIBLE void
MSG_PokeLongBE (sizebuf_t *sb, unsigned offset, int c)
{
if (__builtin_expect (offset + 2 > sb->cursize, 0)) {
Sys_Error ("MSG_PokeLongBE: invalid offset %d / %d",
offset, sb->cursize);
}
byte *buf = sb->data + offset;
*buf++ = ((unsigned int) c) >> 24;
*buf++ = (((unsigned int) c) >> 16) & 0xff;
*buf++ = (((unsigned int) c) >> 8) & 0xff;
*buf = ((unsigned int) c) & 0xff;
}
// reading functions ==========================================================
VISIBLE void
MSG_BeginReading (qmsg_t *msg)
{
msg->readcount = 0;
msg->badread = false;
}
VISIBLE unsigned
MSG_GetReadCount (qmsg_t *msg)
{
return msg->readcount;
}
VISIBLE int
MSG_ReadByte (qmsg_t *msg)
{
if (msg->readcount + 1 <= msg->message->cursize)
return (unsigned char) msg->message->data[msg->readcount++];
msg->badread = true;
return -1;
}
VISIBLE int
MSG_ReadShort (qmsg_t *msg)
{
int c;
if (msg->readcount + 2 <= msg->message->cursize) {
byte *buf = msg->message->data + msg->readcount;
c = *buf++;
c |= (*buf) << 8;
msg->readcount += 2;
return c;
}
msg->readcount = msg->message->cursize;
msg->badread = true;
return -1;
}
VISIBLE int
MSG_ReadShortBE (qmsg_t *msg)
{
int c;
if (msg->readcount + 2 <= msg->message->cursize) {
byte *buf = msg->message->data + msg->readcount;
c = (*buf++) << 8;
c |= *buf;
msg->readcount += 2;
return c;
}
msg->readcount = msg->message->cursize;
msg->badread = true;
return -1;
}
VISIBLE int
MSG_ReadLong (qmsg_t *msg)
{
int c;
if (msg->readcount + 4 <= msg->message->cursize) {
byte *buf = msg->message->data + msg->readcount;
c = *buf++;
c |= (*buf++) << 8;
c |= (*buf++) << 16;
c |= (*buf) << 24;
msg->readcount += 4;
return c;
}
msg->readcount = msg->message->cursize;
msg->badread = true;
return -1;
}
VISIBLE int
MSG_ReadLongBE (qmsg_t *msg)
{
int c;
if (msg->readcount + 4 <= msg->message->cursize) {
byte *buf = msg->message->data + msg->readcount;
c = (*buf++) << 24;
c |= (*buf++) << 16;
c |= (*buf++) << 8;
c |= *buf;
msg->readcount += 4;
return c;
}
msg->readcount = msg->message->cursize;
msg->badread = true;
return -1;
}
VISIBLE float
MSG_ReadFloat (qmsg_t *msg)
{
union {
byte b[4];
float f;
int l;
} dat;
if (msg->readcount + 4 <= msg->message->cursize) {
dat.b[0] = msg->message->data[msg->readcount];
dat.b[1] = msg->message->data[msg->readcount + 1];
dat.b[2] = msg->message->data[msg->readcount + 2];
dat.b[3] = msg->message->data[msg->readcount + 3];
msg->readcount += 4;
dat.l = LittleLong (dat.l);
return dat.f;
}
msg->readcount = msg->message->cursize;
msg->badread = true;
return -1;
}
VISIBLE const char *
MSG_ReadString (qmsg_t *msg)
{
char *string;
size_t len, maxlen;
if (msg->badread || msg->readcount + 1 > msg->message->cursize) {
msg->badread = true;
return "";
}
string = (char *) &msg->message->data[msg->readcount];
maxlen = msg->message->cursize - msg->readcount;
len = strnlen (string, maxlen);
if (len == maxlen) {
msg->readcount = msg->readcount;
msg->badread = true;
if (len + 1 > msg->badread_string_size) {
if (msg->badread_string)
free (msg->badread_string);
msg->badread_string = malloc (len + 1);
msg->badread_string_size = len + 1;
}
if (!msg->badread_string)
Sys_Error ("MSG_ReadString: out of memory");
strncpy (msg->badread_string, string, len);
msg->badread_string[len] = 0;
return msg->badread_string;
}
msg->readcount += len + 1;
return string;
}
VISIBLE int
MSG_ReadBytes (qmsg_t *msg, void *buf, unsigned len)
{
if (msg->badread || len > msg->message->cursize - msg->readcount) {
msg->badread = true;
len = msg->message->cursize - msg->readcount;
}
memcpy (buf, msg->message->data + msg->readcount, len);
msg->readcount += len;
return len;
}
VISIBLE float
MSG_ReadCoord (qmsg_t *msg)
{
return (short) MSG_ReadShort (msg) * (1.0 / 8.0);
}
VISIBLE void
MSG_ReadCoordV (qmsg_t *msg, vec3_t coord)
{
int i;
for (i = 0; i < 3; i++)
coord[i] = (short) MSG_ReadShort (msg) * (1.0 / 8.0);
}
VISIBLE void
MSG_ReadCoordAngleV (qmsg_t *msg, vec3_t coord, vec3_t angles)
{
int i;
for (i = 0; i < 3; i++) {
coord[i] = (short) MSG_ReadShort (msg) * (1.0 / 8.0);
angles[i] = ((signed char) MSG_ReadByte (msg)) * (360.0 / 256.0);
}
}
VISIBLE float
MSG_ReadAngle (qmsg_t *msg)
{
return ((signed char) MSG_ReadByte (msg)) * (360.0 / 256.0);
}
VISIBLE void
MSG_ReadAngleV (qmsg_t *msg, vec3_t angles)
{
int i;
for (i = 0; i < 3; i++)
angles[i] = ((signed char) MSG_ReadByte (msg)) * (360.0 / 256.0);
}
VISIBLE float
MSG_ReadAngle16 (qmsg_t *msg)
{
return (short) MSG_ReadShort (msg) * (360.0 / 65536.0);
}
VISIBLE void
MSG_ReadAngle16V (qmsg_t *msg, vec3_t angles)
{
int i;
for (i = 0; i < 3; i++)
angles[i] = (short) MSG_ReadShort (msg) * (360.0 / 65536.0);
}
VISIBLE int
MSG_ReadUTF8 (qmsg_t *msg)
{
byte *buf, *start, c, min_follow = 0x80;
int val = 0;
unsigned count;
if (msg->badread || msg->message->cursize == msg->readcount) {
msg->badread = true;
return -1;
}
buf = start = msg->message->data + msg->readcount;
c = *buf++;
if (c < 0x80) { // 0x00 - 0x7f 1,7,7
val = c;
count = 1;
} else if (c < 0xc2) { // 0x80 - 0xc1 not a valid first byte
msg->badread = true;
return -1;
} else if (c < 0xe0) { // 0xc0 - 0xdf 2,5,11
count = 2;
val = c & 0x1f;
} else if (c < 0xf0) { // 0xe0 - 0xef 3,4,16
count = 3;
val = c & 0x0f;
min_follow = val == 0xe0 ? 0xa0 : 0x80;
} else if (c < 0xf8) { // 0xf0 - 0xf7 4,3,21
count = 4;
val = c & 0x07;
min_follow = val == 0xf0 ? 0x90 : 0x80;
} else if (c < 0xfc) { // 0xf8 - 0xfb 5,2,26
count = 5;
val = c & 0x03;
min_follow = val == 0xf8 ? 0x88 : 0x80;
} else if (c < 0xfe) { // 0xfc - 0xfd 6,1,31
count = 6;
val = c & 0x01;
min_follow = val == 0xfc ? 0x84 : 0x80;
} else { // 0xfe - 0xff never valid
msg->badread = true;
return -1;
}
if (count > (msg->message->cursize - msg->readcount)) {
msg->badread = true;
return -1;
}
if (count > 2 && *buf < min_follow) {
msg->badread = true;
return -1;
}
while (--count) {
c = *buf++;
if ((c & 0xc0) != 0x80) {
msg->badread = true;
return -1;
}
val <<= 6;
val |= c & 0x3f;
}
msg->readcount += buf - start;
return val;
}