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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
/* HTParse: URI parsing in the WWW Library
HTPARSE
This module is a part of the CERN Common WWW Library. It contains code to parse URIs
and various related things such as:
Parse a URI relative to another URI
Get the URI relative to another URI
Remove redundant data from the URI (HTSimplify and HTCanon)
Expand a local host name into a full domain name (HTExpand)
Search a URI for illigal characters in order to prevent security holes
Escape and Unescape a URI for reserved characters in URLs
Implemented by HTParse.c.
*/
#ifndef HTPARSE_H
#define HTPARSE_H
#include "HTUtils.h"
/*
HTParse: Parse a URI relative to another URI
This returns those parts of a name which are given (and requested) substituting bits
from the related name where necessary.
CONTROL FLAGS FOR HTPARSE
The following are flag bits which may be ORed together to form a number to give the
'wanted' argument to HTParse.
*/
#define PARSE_ACCESS 16
#define PARSE_HOST 8
#define PARSE_PATH 4
#define PARSE_ANCHOR 2
#define PARSE_PUNCTUATION 1
#define PARSE_ALL 31
/*
ON ENTRY
aName A filename given
relatedName A name relative to which aName is to be parsed
wanted A mask for the bits which are wanted.
ON EXIT,
returns A pointer to a malloc'd string which MUST BE FREED
*/
PUBLIC char * HTParse PARAMS(( const char * aName,
const char * relatedName,
int wanted));
/*
HTStrip: Strip white space off a string
ON EXIT
Return value points to first non-white character, or to 0 if none.
All trailing white space is OVERWRITTEN with zero.
*/
#ifdef __STDC__
extern char * HTStrip(char * s);
#else
extern char * HTStrip();
#endif
/*
HTSimplify: Simplify a UTL
A URI is allowed to contain the seqeunce xxx/../ which may be replaced by "" , and the
seqeunce "/./" which may be replaced by "/". Simplification helps us recognize
duplicate URIs. Thus, the following transformations are done:
/etc/junk/../fred
becomes
/etc/fred
/etc/junk/./fred
becomes
/etc/junk/fred
but we should NOT change
http://fred.xxx.edu/../.. or
../../albert.html
In the same manner, the following prefixed are preserved:
./
//
In order to avoid empty URIs the following URIs become:
/fred/..
becomes /fred/..
/fred/././..
becomes /fred/..
/fred/.././junk/.././
becomes /fred/..
If more than one set of `://' is found (several proxies in cascade) then only the part
after the last `://' is simplified.
*/
PUBLIC char *HTSimplify PARAMS((char *filename));
/*
HTRelative: Make Relative (Partial) URI
This function creates and returns a string which gives an expression of one address as
related to another. Where there is no relation, an absolute address is retured.
ON ENTRY,
Both names must be absolute, fully qualified names of nodes (no anchor bits)
ON EXIT,
The return result points to a newly allocated name which, if parsed by HTParse relative
to relatedName, will yield aName. The caller is responsible for freeing the resulting
name later.
*/
#ifdef __STDC__
extern char * HTRelative(const char * aName, const char *relatedName);
#else
extern char * HTRelative();
#endif
/*
HTExpand: Expand a Local Host Name Into a Full Domain Name
This function expands the host name of the URI from a local name to a full domain name,
converts the host name to lower case and takes away `:80', `:70' and `:21'. The
advantage by doing this is that we only have one entry in the host case and one entry
in the document cache.
*/
PUBLIC char *HTCanon PARAMS (( char ** filename,
char * host));
/*
HTEscape: Encode unacceptable characters in string
This funtion takes a string containing any sequence of ASCII characters, and returns a
malloced string containing the same infromation but with all "unacceptable" characters
represented in the form %xy where X and Y are two hex digits.
*/
PUBLIC char * HTEscape PARAMS((CONST char * str, unsigned char mask));
/*
The following are valid mask values. The terms are the BNF names in the URI document.
*/
#define URL_XALPHAS (unsigned char) 1
#define URL_XPALPHAS (unsigned char) 2
#define URL_PATH (unsigned char) 4
/*
HTUnEscape: Decode %xx escaped characters
This function takes a pointer to a string in which character smay have been encoded in
%xy form, where xy is the acsii hex code for character 16x+y. The string is converted
in place, as it will never grow.
*/
extern char * HTUnEscape PARAMS(( char * str));
/*
Prevent Security Holes
HTCleanTelnetString() makes sure that the given string doesn't contain characters that
could cause security holes, such as newlines in ftp, gopher, news or telnet URLs; more
specifically: allows everything between hexadesimal ASCII 20-7E, and also A0-FE,
inclusive.
str the string that is *modified* if necessary. The string will be
truncated at the first illegal character that is encountered.
returns YES, if the string was modified. NO, otherwise.
*/
PUBLIC BOOL HTCleanTelnetString PARAMS((char * str));
/*
*/
#endif /* HTPARSE_H */
/*
End of HTParse Module */
|
