mirror of
https://github.com/transmission/transmission
synced 2024-12-25 01:03:01 +00:00
342 lines
7.9 KiB
C
342 lines
7.9 KiB
C
/*
|
|
* This file Copyright (C) 2008-2014 Mnemosyne LLC
|
|
*
|
|
* It may be used under the GNU GPL versions 2 or 3
|
|
* or any future license endorsed by Mnemosyne LLC.
|
|
*
|
|
* $Id$
|
|
*/
|
|
|
|
#include <assert.h>
|
|
#include <ctype.h> /* isdigit() */
|
|
#include <errno.h>
|
|
#include <stdlib.h> /* strtoul() */
|
|
#include <string.h> /* strlen(), memchr() */
|
|
|
|
#include <event2/buffer.h>
|
|
|
|
#include "ConvertUTF.h"
|
|
|
|
#define __LIBTRANSMISSION_VARIANT_MODULE___
|
|
#include "transmission.h"
|
|
#include "ptrarray.h"
|
|
#include "utils.h" /* tr_snprintf() */
|
|
#include "variant.h"
|
|
#include "variant-common.h"
|
|
|
|
/***
|
|
**** tr_variantParse()
|
|
**** tr_variantLoad()
|
|
***/
|
|
|
|
/**
|
|
* The initial i and trailing e are beginning and ending delimiters.
|
|
* You can have negative numbers such as i-3e. You cannot prefix the
|
|
* number with a zero such as i04e. However, i0e is valid.
|
|
* Example: i3e represents the integer "3"
|
|
* NOTE: The maximum number of bit of this integer is unspecified,
|
|
* but to handle it as a signed 64bit integer is mandatory to handle
|
|
* "large files" aka .torrent for more that 4Gbyte
|
|
*/
|
|
int
|
|
tr_bencParseInt (const uint8_t * buf,
|
|
const uint8_t * bufend,
|
|
const uint8_t ** setme_end,
|
|
int64_t * setme_val)
|
|
{
|
|
char * endptr;
|
|
const void * begin;
|
|
const void * end;
|
|
int64_t val;
|
|
|
|
if (buf >= bufend)
|
|
return EILSEQ;
|
|
if (*buf != 'i')
|
|
return EILSEQ;
|
|
|
|
begin = buf + 1;
|
|
end = memchr (begin, 'e', (bufend - buf) - 1);
|
|
if (end == NULL)
|
|
return EILSEQ;
|
|
|
|
errno = 0;
|
|
val = evutil_strtoll (begin, &endptr, 10);
|
|
if (errno || (endptr != end)) /* incomplete parse */
|
|
return EILSEQ;
|
|
if (val && * (const char*)begin == '0') /* no leading zeroes! */
|
|
return EILSEQ;
|
|
|
|
*setme_end = (const uint8_t*)end + 1;
|
|
*setme_val = val;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Byte strings are encoded as follows:
|
|
* <string length encoded in base ten ASCII>:<string data>
|
|
* Note that there is no constant beginning delimiter, and no ending delimiter.
|
|
* Example: 4:spam represents the string "spam"
|
|
*/
|
|
int
|
|
tr_bencParseStr (const uint8_t * buf,
|
|
const uint8_t * bufend,
|
|
const uint8_t ** setme_end,
|
|
const uint8_t ** setme_str,
|
|
size_t * setme_strlen)
|
|
{
|
|
const void * end;
|
|
size_t len;
|
|
char * ulend;
|
|
const uint8_t * strbegin;
|
|
const uint8_t * strend;
|
|
|
|
if (buf >= bufend)
|
|
goto err;
|
|
|
|
if (!isdigit (*buf))
|
|
goto err;
|
|
|
|
end = memchr (buf, ':', bufend - buf);
|
|
if (end == NULL)
|
|
goto err;
|
|
|
|
errno = 0;
|
|
len = strtoul ((const char*)buf, &ulend, 10);
|
|
if (errno || ulend != end)
|
|
goto err;
|
|
|
|
strbegin = (const uint8_t*)end + 1;
|
|
strend = strbegin + len;
|
|
if ((strend<strbegin) || (strend>bufend))
|
|
goto err;
|
|
|
|
*setme_end = (const uint8_t*)end + 1 + len;
|
|
*setme_str = (const uint8_t*)end + 1;
|
|
*setme_strlen = len;
|
|
return 0;
|
|
|
|
err:
|
|
*setme_end = NULL;
|
|
*setme_str = NULL;
|
|
*setme_strlen= 0;
|
|
return EILSEQ;
|
|
}
|
|
|
|
static tr_variant*
|
|
get_node (tr_ptrArray * stack, tr_quark * key, tr_variant * top, int * err)
|
|
{
|
|
tr_variant * node = NULL;
|
|
|
|
if (tr_ptrArrayEmpty (stack))
|
|
{
|
|
node = top;
|
|
}
|
|
else
|
|
{
|
|
tr_variant * parent = tr_ptrArrayBack (stack);
|
|
|
|
if (tr_variantIsList (parent))
|
|
{
|
|
node = tr_variantListAdd (parent);
|
|
}
|
|
else if (*key && tr_variantIsDict (parent))
|
|
{
|
|
node = tr_variantDictAdd (parent, *key);
|
|
*key = 0;
|
|
}
|
|
else
|
|
{
|
|
*err = EILSEQ;
|
|
}
|
|
}
|
|
|
|
return node;
|
|
}
|
|
|
|
/**
|
|
* This function's previous recursive implementation was
|
|
* easier to read, but was vulnerable to a smash-stacking
|
|
* attack via maliciously-crafted bencoded data. (#667)
|
|
*/
|
|
int
|
|
tr_variantParseBenc (const void * buf_in,
|
|
const void * bufend_in,
|
|
tr_variant * top,
|
|
const char ** setme_end)
|
|
{
|
|
int err = 0;
|
|
const uint8_t * buf = buf_in;
|
|
const uint8_t * bufend = bufend_in;
|
|
tr_ptrArray stack = TR_PTR_ARRAY_INIT;
|
|
tr_quark key = 0;
|
|
|
|
tr_variantInit (top, 0);
|
|
|
|
while (buf != bufend)
|
|
{
|
|
if (buf > bufend) /* no more text to parse... */
|
|
err = EILSEQ;
|
|
|
|
if (err)
|
|
break;
|
|
|
|
if (*buf == 'i') /* int */
|
|
{
|
|
int64_t val;
|
|
const uint8_t * end;
|
|
tr_variant * v;
|
|
|
|
if ((err = tr_bencParseInt (buf, bufend, &end, &val)))
|
|
break;
|
|
buf = end;
|
|
|
|
if ((v = get_node (&stack, &key, top, &err)))
|
|
tr_variantInitInt (v, val);
|
|
}
|
|
else if (*buf == 'l') /* list */
|
|
{
|
|
tr_variant * v;
|
|
|
|
++buf;
|
|
|
|
if ((v = get_node (&stack, &key, top, &err)))
|
|
{
|
|
tr_variantInitList (v, 0);
|
|
tr_ptrArrayAppend (&stack, v);
|
|
}
|
|
}
|
|
else if (*buf == 'd') /* dict */
|
|
{
|
|
tr_variant * v;
|
|
|
|
++buf;
|
|
|
|
if ((v = get_node (&stack, &key, top, &err)))
|
|
{
|
|
tr_variantInitDict (v, 0);
|
|
tr_ptrArrayAppend (&stack, v);
|
|
}
|
|
}
|
|
else if (*buf == 'e') /* end of list or dict */
|
|
{
|
|
++buf;
|
|
|
|
if (tr_ptrArrayEmpty (&stack) || (key != 0))
|
|
{
|
|
err = EILSEQ;
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
tr_ptrArrayPop (&stack);
|
|
if (tr_ptrArrayEmpty (&stack))
|
|
break;
|
|
}
|
|
}
|
|
else if (isdigit (*buf)) /* string? */
|
|
{
|
|
tr_variant * v;
|
|
const uint8_t * end;
|
|
const uint8_t * str;
|
|
size_t str_len;
|
|
|
|
if ((err = tr_bencParseStr (buf, bufend, &end, &str, &str_len)))
|
|
break;
|
|
buf = end;
|
|
|
|
if (!key && !tr_ptrArrayEmpty(&stack) && tr_variantIsDict(tr_ptrArrayBack(&stack)))
|
|
key = tr_quark_new (str, str_len);
|
|
else if ((v = get_node (&stack, &key, top, &err)))
|
|
tr_variantInitStr (v, str, str_len);
|
|
}
|
|
else /* invalid bencoded text... march past it */
|
|
{
|
|
++buf;
|
|
}
|
|
|
|
if (tr_ptrArrayEmpty (&stack))
|
|
break;
|
|
}
|
|
|
|
if (!err && (!top->type || !tr_ptrArrayEmpty(&stack)))
|
|
err = EILSEQ;
|
|
|
|
if (!err && setme_end)
|
|
*setme_end = (const char*) buf;
|
|
|
|
tr_ptrArrayDestruct (&stack, NULL);
|
|
return err;
|
|
}
|
|
|
|
/****
|
|
*****
|
|
****/
|
|
|
|
static void
|
|
saveIntFunc (const tr_variant * val, void * evbuf)
|
|
{
|
|
evbuffer_add_printf (evbuf, "i%" PRId64 "e", val->val.i);
|
|
}
|
|
|
|
static void
|
|
saveBoolFunc (const tr_variant * val, void * evbuf)
|
|
{
|
|
if (val->val.b)
|
|
evbuffer_add (evbuf, "i1e", 3);
|
|
else
|
|
evbuffer_add (evbuf, "i0e", 3);
|
|
}
|
|
|
|
static void
|
|
saveRealFunc (const tr_variant * val, void * evbuf)
|
|
{
|
|
int len;
|
|
char buf[128];
|
|
|
|
len = tr_snprintf (buf, sizeof (buf), "%f", val->val.d);
|
|
evbuffer_add_printf (evbuf, "%d:", len);
|
|
evbuffer_add (evbuf, buf, len);
|
|
}
|
|
|
|
static void
|
|
saveStringFunc (const tr_variant * v, void * evbuf)
|
|
{
|
|
size_t len;
|
|
const char * str;
|
|
tr_variantGetStr (v, &str, &len);
|
|
evbuffer_add_printf (evbuf, "%"TR_PRIuSIZE":", len);
|
|
evbuffer_add (evbuf, str, len);
|
|
}
|
|
|
|
static void
|
|
saveDictBeginFunc (const tr_variant * val UNUSED, void * evbuf)
|
|
{
|
|
evbuffer_add (evbuf, "d", 1);
|
|
}
|
|
|
|
static void
|
|
saveListBeginFunc (const tr_variant * val UNUSED, void * evbuf)
|
|
{
|
|
evbuffer_add (evbuf, "l", 1);
|
|
}
|
|
|
|
static void
|
|
saveContainerEndFunc (const tr_variant * val UNUSED, void * evbuf)
|
|
{
|
|
evbuffer_add (evbuf, "e", 1);
|
|
}
|
|
|
|
static const struct VariantWalkFuncs walk_funcs = { saveIntFunc,
|
|
saveBoolFunc,
|
|
saveRealFunc,
|
|
saveStringFunc,
|
|
saveDictBeginFunc,
|
|
saveListBeginFunc,
|
|
saveContainerEndFunc };
|
|
|
|
void
|
|
tr_variantToBufBenc (const tr_variant * top, struct evbuffer * buf)
|
|
{
|
|
tr_variantWalk (top, &walk_funcs, buf, true);
|
|
}
|
|
|