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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
|
/* tinyproxy - A fast light-weight HTTP proxy
* Copyright (C) 2003 Steven Young <sdyoung@miranda.org>
*
* 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 the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* This file contains source code for the handling and display of
* HTML error pages with variable substitution.
*/
#include "main.h"
#include "common.h"
#include "buffer.h"
#include "conns.h"
#include "heap.h"
#include "html-error.h"
#include "network.h"
#include "utils.h"
/*
* Add an error number -> filename mapping to the errorpages list.
*/
#define ERRORNUM_BUFSIZE 8 /* this is more than required */
#define ERRPAGES_BUCKETCOUNT 16
int add_new_errorpage (char *filepath, unsigned int errornum)
{
char errornbuf[ERRORNUM_BUFSIZE];
config.errorpages = hashmap_create (ERRPAGES_BUCKETCOUNT);
if (!config.errorpages)
return (-1);
snprintf (errornbuf, ERRORNUM_BUFSIZE, "%u", errornum);
if (hashmap_insert (config.errorpages, errornbuf,
filepath, strlen (filepath) + 1) < 0)
return (-1);
return (0);
}
/*
* Get the file appropriate for a given error.
*/
static char *get_html_file (unsigned int errornum)
{
hashmap_iter result_iter;
char errornbuf[ERRORNUM_BUFSIZE];
char *key;
static char *val;
assert (errornum >= 100 && errornum < 1000);
if (!config.errorpages)
return (config.errorpage_undef);
snprintf (errornbuf, ERRORNUM_BUFSIZE, "%u", errornum);
result_iter = hashmap_find (config.errorpages, errornbuf);
if (hashmap_is_end (config.errorpages, result_iter))
return (config.errorpage_undef);
if (hashmap_return_entry (config.errorpages, result_iter,
&key, (void **) &val) < 0)
return (config.errorpage_undef);
return (val);
}
/*
* Look up the value for a variable.
*/
static char *lookup_variable (struct conn_s *connptr, const char *varname)
{
hashmap_iter result_iter;
char *key;
static char *data;
result_iter = hashmap_find (connptr->error_variables, varname);
if (hashmap_is_end (connptr->error_variables, result_iter))
return (NULL);
if (hashmap_return_entry (connptr->error_variables, result_iter,
&key, (void **) &data) < 0)
return (NULL);
return (data);
}
#define HTML_BUFSIZE 4096
/*
* Send an already-opened file to the client with variable substitution.
*/
int send_html_file (FILE * infile, struct conn_s *connptr)
{
char inbuf[HTML_BUFSIZE], *varstart = NULL, *p;
const char *varval;
int in_variable = 0, writeret;
while (fgets (inbuf, HTML_BUFSIZE, infile) != NULL) {
for (p = inbuf; *p; p++) {
switch (*p) {
case '}':
if (in_variable) {
*p = '\0';
varval =
(const char *)
lookup_variable (connptr, varstart);
if (!varval)
varval = "(unknown)";
writeret =
write_message (connptr->client_fd,
"%s", varval);
if (writeret)
return (writeret);
in_variable = 0;
} else {
writeret =
write_message (connptr->client_fd,
"%c", *p);
if (writeret)
return (writeret);
}
break;
case '{':
/* a {{ will print a single {. If we are NOT
* already in a { variable, then proceed with
* setup. If we ARE already in a { variable,
* this code will fallthrough to the code that
* just dumps a character to the client fd.
*/
if (!in_variable) {
varstart = p + 1;
in_variable++;
} else
in_variable = 0;
default:
if (!in_variable) {
writeret =
write_message (connptr->client_fd,
"%c", *p);
if (writeret)
return (writeret);
}
}
}
in_variable = 0;
}
return (0);
}
int send_http_headers (struct conn_s *connptr, int code, const char *message)
{
const char *headers =
"HTTP/1.0 %d %s\r\n"
"Server: %s/%s\r\n"
"Content-Type: text/html\r\n" "Connection: close\r\n" "\r\n";
return (write_message (connptr->client_fd, headers,
code, message, PACKAGE, VERSION));
}
/*
* Display an error to the client.
*/
int send_http_error_message (struct conn_s *connptr)
{
char *error_file;
FILE *infile;
int ret;
const char *fallback_error =
"<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n"
"<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.1//EN\" "
"\"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd\">\n"
"<html>\n"
"<head><title>%d %s</title></head>\n"
"<body>\n"
"<h1>%s</h1>\n"
"<p>%s</p>\n"
"<hr />\n"
"<p><em>Generated by %s version %s.</em></p>\n" "</body>\n"
"</html>\n";
send_http_headers (connptr, connptr->error_number,
connptr->error_string);
error_file = get_html_file (connptr->error_number);
if (!(infile = fopen (error_file, "r"))) {
char *detail = lookup_variable (connptr, "detail");
return (write_message (connptr->client_fd, fallback_error,
connptr->error_number,
connptr->error_string,
connptr->error_string,
detail, PACKAGE, VERSION));
}
ret = send_html_file (infile, connptr);
fclose (infile);
return (ret);
}
/*
* Add a key -> value mapping for HTML file substitution.
*/
#define ERRVAR_BUCKETCOUNT 16
int
add_error_variable (struct conn_s *connptr, const char *key, const char *val)
{
if (!connptr->error_variables)
if (!
(connptr->error_variables =
hashmap_create (ERRVAR_BUCKETCOUNT)))
return (-1);
return hashmap_insert (connptr->error_variables, key, val,
strlen (val) + 1);
}
#define ADD_VAR_RET(x, y) \
do { \
if (y == NULL) \
break; \
if (add_error_variable(connptr, x, y) < 0) \
return -1; \
} while (0)
/*
* Set some standard variables used by all HTML pages
*/
int add_standard_vars (struct conn_s *connptr)
{
char errnobuf[16];
char timebuf[30];
time_t global_time;
snprintf (errnobuf, sizeof errnobuf, "%d", connptr->error_number);
ADD_VAR_RET ("errno", errnobuf);
ADD_VAR_RET ("cause", connptr->error_string);
ADD_VAR_RET ("request", connptr->request_line);
ADD_VAR_RET ("clientip", connptr->client_ip_addr);
ADD_VAR_RET ("clienthost", connptr->client_string_addr);
/* The following value parts are all non-NULL and will
* trigger warnings in ADD_VAR_RET(), so we use
* add_error_variable() directly.
*/
global_time = time (NULL);
strftime (timebuf, sizeof (timebuf), "%a, %d %b %Y %H:%M:%S GMT",
gmtime (&global_time));
add_error_variable (connptr, "date", timebuf);
add_error_variable (connptr, "website",
"http://www.banu.com/tinyproxy/");
add_error_variable (connptr, "version", VERSION);
add_error_variable (connptr, "package", PACKAGE);
return (0);
}
/*
* Add the error information to the conn structure.
*/
int
indicate_http_error (struct conn_s *connptr, int number,
const char *message, ...)
{
va_list ap;
char *key, *val;
va_start (ap, message);
while ((key = va_arg (ap, char *))) {
val = va_arg (ap, char *);
if (add_error_variable (connptr, key, val) == -1) {
va_end (ap);
return (-1);
}
}
connptr->error_number = number;
connptr->error_string = safestrdup (message);
va_end (ap);
return (add_standard_vars (connptr));
}
|
