1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
$id$ */
/* Opentracker */
#include "scan_urlencoded_query.h"
/* Libwofat */
#include "scan.h"
/* Idea is to do a in place replacement or guarantee at least
strlen( string ) bytes in deststring
watch http://www.ietf.org/rfc/rfc2396.txt
unreserved = alphanum | mark
mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
we add '%' to the matrix to not stop at encoded chars.
After losing too many requests to being too strict, add the following characters to reserved matrix
relax = "+" | "," | "/" | ";" | "<" | ">" | ":"
*/
/* This matrix holds for each ascii character the information,
whether it is a non-terminating character for on of the three
scan states we are in, that is 'path', 'param' and 'value' from
/path?param=value¶m=value, it is encoded in bit 0, 1 and 2
respectively
The top bit of lower nibble indicates, whether this character is
a hard terminator, ie. \0, \n or \s, where the whole scanning
process should terminate
*/
static const unsigned char is_unreserved[256] = {
8,0,0,0,0,0,0,0,0,0,8,0,0,8,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,7,8,8,8,7,0,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,4,7,6,
4,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,7,
8,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,7,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
};
/* Do a fast nibble to hex representation conversion */
static unsigned char fromhex(unsigned char x) {
x-='0'; if( x<=9) return x;
x&=~0x20; x-='A'-'0';
if( x<6 ) return x+10;
return 0xff;
}
/* Skip the value of a param=value pair */
void scan_urlencoded_skipvalue( char **string ) {
const unsigned char* s=*(const unsigned char**) string;
unsigned char f;
/* Since we are asked to skip the 'value', we assume to stop at
terminators for a 'value' string position */
while( ( f = is_unreserved[ *s++ ] ) & SCAN_SEARCHPATH_VALUE );
/* If we stopped at a hard terminator like \0 or \n, make the
next scan_urlencoded_query encounter it again */
if( f & SCAN_SEARCHPATH_TERMINATOR ) --s;
*string = (char*)s;
}
ssize_t scan_urlencoded_query(char **string, char *deststring, SCAN_SEARCHPATH_FLAG flags) {
const unsigned char* s=*(const unsigned char**) string;
unsigned char *d = (unsigned char*)deststring;
unsigned char b, c;
/* This is the main decoding loop.
'flag' determines, which characters are non-terminating in current context
(ie. stop at '=' and '&' if scanning for a 'param'; stop at '?' if scanning for the path )
*/
while( is_unreserved[ c = *s++ ] & flags ) {
/* When encountering an url escaped character, try to decode */
if( c=='%') {
if( ( b = fromhex(*s++) ) == 0xff ) return -1;
if( ( c = fromhex(*s++) ) == 0xff ) return -1;
c|=(b<<4);
}
/* Write (possibly decoded) character to output */
*d++ = c;
}
switch( c ) {
case 0: case '\r': case '\n': case ' ':
/* If we started scanning on a hard terminator, indicate we've finished */
if( d == (unsigned char*)deststring ) return -2;
/* Else make the next call to scan_urlencoded_param encounter it again */
--s;
break;
case '?':
/* XXX to help us parse path?param=value?param=value?... sent by µTorrent 1600
do not return an error but silently terminate
if( flags != SCAN_PATH ) return -1; */
break;
case '=':
if( flags != SCAN_SEARCHPATH_PARAM ) return -1;
break;
case '&':
if( flags == SCAN_PATH ) return -1;
if( flags == SCAN_SEARCHPATH_PARAM ) --s;
break;
default:
return -1;
}
*string = (char *)s;
return d - (unsigned char*)deststring;
}
ssize_t scan_fixed_int( char *data, size_t len, int *tmp ) {
int minus = 0;
*tmp = 0;
if( *data == '-' ) --len, ++data, ++minus;
while( (len > 0) && (*data >= '0') && (*data <= '9') ) { --len; *tmp = 10**tmp + *data++-'0'; }
if( minus ) *tmp = -*tmp;
return len;
}
ssize_t scan_fixed_ip( char *data, size_t len, unsigned char ip[4] ) {
int u, i;
for( i=0; i<4; ++i ) {
ssize_t j = scan_fixed_int( data, len, &u );
if( j == (ssize_t)len ) return len;
ip[i] = u;
data += len - j;
len = j;
if ( i<3 ) {
if( !len || *data != '.') return -1;
--len; ++data;
}
}
return len;
}
const char *g_version_scan_urlencoded_query_c = "$Source$: $Revision$\n";
|
