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
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
|
/* $Id: utils.c,v 1.25 2002-04-16 03:22:16 rjkaes Exp $
*
* Misc. routines which are used by the various functions to handle strings
* and memory allocation and pretty much anything else we can think of. Also,
* the load cutoff routine is in here. Could not think of a better place for
* it, so it's in here.
*
* Copyright (C) 1998 Steven Young
* Copyright (C) 1999,2001 Robert James Kaes (rjkaes@flarenet.com)
*
* 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, 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.
*/
#include "tinyproxy.h"
#include "buffer.h"
#include "conns.h"
#include "log.h"
#include "sock.h"
#include "utils.h"
/*
* These are the debugging calloc, malloc, and free versions
*/
#ifndef NDEBUG
void *
debugging_calloc(size_t nmemb, size_t size, const char *file,
unsigned long line)
{
void *ptr = calloc(nmemb, size);
fprintf(stderr, "{calloc: %p:%u x %u} %s:%lu\n", ptr, nmemb, size, file,
line);
return ptr;
}
void *
debugging_malloc(size_t size, const char *file, unsigned long line)
{
void *ptr = malloc(size);
fprintf(stderr, "{malloc: %p:%u} %s:%lu\n", ptr, size, file, line);
return ptr;
}
void *
debugging_realloc(void *ptr, size_t size, const char *file, unsigned long line)
{
void *newptr = realloc(ptr, size);
fprintf(stderr, "{realloc: %p -> %p:%u} %s:%lu\n", ptr, newptr, size,
file, line);
return newptr;
}
void
debugging_free(void *ptr, const char *file, unsigned long line)
{
fprintf(stderr, "{free: %p} %s:%lu\n", ptr, file, line);
free(ptr);
return;
}
#endif
#define HEADER_SIZE (1024 * 8)
/*
* Build the data for a complete HTTP & HTML message for the client.
*/
int
send_http_message(struct conn_s *connptr, int http_code,
const char *error_title, const char *message)
{
static char *headers = \
"HTTP/1.0 %d %s\r\n" \
"Server: %s/%s\r\n" \
"Date: %s\r\n" \
"Content-Type: text/html\r\n" \
"Content-Length: %d\r\n" \
"Connection: close\r\n" \
"\r\n";
char timebuf[30];
time_t global_time;
size_t message_len = strlen(message);
global_time = time(NULL);
strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT",
gmtime(&global_time));
write_message(connptr->client_fd,
headers,
http_code, error_title, PACKAGE, VERSION, timebuf,
message_len);
return safe_write(connptr->client_fd, message, message_len);
}
/*
* Display an error to the client.
*/
int
send_http_error_message(struct conn_s *connptr)
{
static char *message = \
"<html><head><title>%s</title></head>\r\n" \
"<body>\r\n" \
"<font size=\"+2\">Cache Error!</font><br>\r\n" \
"An error of type %d occurred: %s\r\n" \
"<hr>\r\n" \
"<font size=\"-1\"><em>Generated by %s (%s)</em></font>\r\n" \
"</body></html>\r\n\r\n";
char *message_buffer;
char *tmpbuf;
size_t size = (1024 * 8); /* start with 8 KB */
ssize_t n;
int ret;
message_buffer = safemalloc(size);
if (!message_buffer)
return -1;
/*
* Build a new line. Keep increasing the size until the line fits.
* See the write_message() function in sock.c for more information.
*/
while (1) {
n = snprintf(message_buffer, size, message,
connptr->error_string, connptr->error_number,
connptr->error_string, PACKAGE, VERSION);
if (n > -1 && n < size)
break;
if (n > - 1)
size = n + 1;
else
size *= 2;
if ((tmpbuf = saferealloc(message_buffer, size)) == NULL) {
safefree(message_buffer);
return -1;
} else
message_buffer = tmpbuf;
}
ret = send_http_message(connptr, connptr->error_number,
connptr->error_string, message_buffer);
safefree(message_buffer);
return ret;
}
/*
* Add the error information to the conn structure.
*/
int
indicate_http_error(struct conn_s* connptr, int number, const char* string)
{
connptr->error_string = strdup(string);
if (!connptr->error_string)
return -1;
connptr->error_number = number;
return 0;
}
void
makedaemon(void)
{
if (fork() != 0)
exit(0);
setsid();
signal(SIGHUP, SIG_IGN);
if (fork() != 0)
exit(0);
chdir("/");
umask(077);
close(0);
close(1);
close(2);
}
/*
* Safely creates filename and returns the low-level file descriptor.
*/
int
create_file_safely(const char *filename)
{
struct stat lstatinfo;
int fildes;
/*
* lstat() the file. If it doesn't exist, create it with O_EXCL.
* If it does exist, open it for writing and perform the fstat()
* check.
*/
if (lstat(filename, &lstatinfo) < 0) {
/*
* If lstat() failed for any reason other than "file not
* existing", exit.
*/
if (errno != ENOENT) {
log_message(LOG_ERR,
"create_file_safely: Error checking PID file %s: %s.",
filename, strerror(errno));
return -1;
}
/*
* The file doesn't exist, so create it with O_EXCL to make
* sure an attacker can't slip in a file between the lstat()
* and open()
*/
if ((fildes =
open(filename, O_RDWR | O_CREAT | O_EXCL, 0600)) < 0) {
log_message(LOG_ERR,
"create_file_safely: Could not create PID file %s: %s.",
filename, strerror(errno));
return -1;
}
} else {
struct stat fstatinfo;
/*
* Open an existing file.
*/
if ((fildes = open(filename, O_RDWR)) < 0) {
log_message(LOG_ERR,
"create_file_safely: Could not open PID file %s: %s.",
filename, strerror(errno));
return -1;
}
/*
* fstat() the opened file and check that the file mode bits,
* inode, and device match.
*/
if (fstat(fildes, &fstatinfo) < 0
|| lstatinfo.st_mode != fstatinfo.st_mode
|| lstatinfo.st_ino != fstatinfo.st_ino
|| lstatinfo.st_dev != fstatinfo.st_dev) {
log_message(LOG_ERR,
"create_file_safely: The PID file %s has been changed before it could be opened.",
filename);
close(fildes);
return -1;
}
/*
* If the above check was passed, we know that the lstat()
* and fstat() were done on the same file. Now we check that
* there's only one link, and that it's a normal file (this
* isn't strictly necessary because the fstat() vs lstat()
* st_mode check would also find this)
*/
if (fstatinfo.st_nlink > 1 || !S_ISREG(lstatinfo.st_mode)) {
log_message(LOG_ERR,
"create_file_safely: The PID file %s has too many links, or is not a regular file: %s.",
filename, strerror(errno));
close(fildes);
return -1;
}
/*
* On systems whcih don't support ftruncate() the best we can
* do is to close the file and reopen it in create mode, which
* unfortunately leads to a race condition, however "systems
* which don't support ftruncate()" is pretty much SCO only,
* and if you're using that you deserve what you get.
* ("Little sympathy has been extended")
*/
#ifdef HAVE_FTRUNCATE
ftruncate(fildes, 0);
#else
close(fildes);
if ((fildes =
open(filename, O_RDWR | O_CREAT | O_TRUNC, 0600)) < 0) {
log_message(LOG_ERR,
"create_file_safely: Could not open PID file %s: %s.",
filename, strerror(errno));
return -1;
}
#endif /* HAVE_FTRUNCATE */
}
return fildes;
}
/*
* Write the PID of the program to the specified file.
*/
void
pidfile_create(const char *filename)
{
int fildes;
FILE *fd;
/*
* Create a new file
*/
if ((fildes = create_file_safely(filename)) < 0)
exit(1);
/*
* Open a stdio file over the low-level one.
*/
if ((fd = fdopen(fildes, "w")) == NULL) {
log_message(LOG_ERR,
"pidfile_create: fdopen() error on PID file %s: %s.",
filename, strerror(errno));
close(fildes);
unlink(filename);
exit(1);
}
fprintf(fd, "%ld\n", (long) getpid());
fclose(fd);
}
#ifndef HAVE_STRLCPY
/*
* Function API taken from OpenBSD. Like strncpy(), but does not 0 fill the
* buffer, and always NULL terminates the buffer. size is the size of the
* destination buffer.
*/
size_t
strlcpy(char *dst, const char *src, size_t size)
{
size_t len = strlen(src);
size_t ret = len;
if (len >= size)
len = size - 1;
memcpy(dst, src, len);
dst[len] = '\0';
return ret;
}
#endif
#ifndef HAVE_STRLCAT
/*
* Function API taken from OpenBSD. Like strncat(), but does not 0 fill the
* buffer, and always NULL terminates the buffer. size is the length of the
* buffer, which should be one more than the maximum resulting string
* length.
*/
size_t
strlcat(char *dst, const char *src, size_t size)
{
size_t len1 = strlen(dst);
size_t len2 = strlen(src);
size_t ret = len1 + len2;
if (len1 + len2 >= size)
len2 = size - len1 - 1;
if (len2 > 0) {
memcpy(dst + len1, src, len2);
dst[len1 + len2] = '\0';
}
return ret;
}
#endif
/*
* Removes any new-line or carriage-return characters from the end of the
* string. This function is named afrer the same function in Perl.
* "length" should be the number of characters in the buffer, not including
* the trailing NULL.
*
* Returns the number of characters removed from the end of the string.
*/
size_t
chomp(char *buffer, size_t length)
{
size_t chars;
assert(buffer != NULL);
chars = 0;
--length;
while (buffer[length] == '\r' || buffer[length] == '\n') {
buffer[length--] = '\0';
chars++;
if (length < 0)
break;
}
return chars;
}
|
