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
|
/* $Id: network.c,v 1.1 2002-05-23 04:41:48 rjkaes Exp $
*
* The functions found here are used for communicating across a
* network. They include both safe reading and writing (which are
* the basic building blocks) along with two functions for
* easily reading a line of text from the network, and a function
* to write an arbitrary amount of data to the network.
*
* Copyright (C) 2002 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 "heap.h"
#include "network.h"
/*
* Write the buffer to the socket. If an EINTR occurs, pick up and try
* again. Keep sending until the buffer has been sent.
*/
ssize_t
safe_write(int fd, const char *buffer, size_t count)
{
ssize_t len;
size_t bytestosend;
assert(fd >= 0);
assert(buffer != NULL);
assert(count > 0);
bytestosend = count;
while (1) {
len = send(fd, buffer, bytestosend, MSG_NOSIGNAL);
if (len < 0) {
if (errno == EINTR)
continue;
else
return -errno;
}
if (len == bytestosend)
break;
buffer += len;
bytestosend -= len;
}
return count;
}
/*
* Matched pair for safe_write(). If an EINTR occurs, pick up and try
* again.
*/
ssize_t
safe_read(int fd, char *buffer, size_t count)
{
ssize_t len;
do {
len = read(fd, buffer, count);
} while (len < 0 && errno == EINTR);
return len;
}
/*
* Send a "message" to the file descriptor provided. This handles the
* differences between the various implementations of vsnprintf. This code
* was basically stolen from the snprintf() man page of Debian Linux
* (although I did fix a memory leak. :)
*/
int
write_message(int fd, const char *fmt, ...)
{
ssize_t n;
size_t size = (1024 * 8); /* start with 8 KB and go from there */
char *buf, *tmpbuf;
va_list ap;
if ((buf = safemalloc(size)) == NULL)
return -1;
while (1) {
va_start(ap, fmt);
n = vsnprintf(buf, size, fmt, ap);
va_end(ap);
/* If that worked, break out so we can send the buffer */
if (n > -1 && n < size)
break;
/* Else, try again with more space */
if (n > -1)
/* precisely what is needed (glibc2.1) */
size = n + 1;
else
/* twice the old size (glibc2.0) */
size *= 2;
if ((tmpbuf = saferealloc(buf, size)) == NULL) {
safefree(buf);
return -1;
} else
buf = tmpbuf;
}
if (safe_write(fd, buf, n) < 0) {
safefree(buf);
return -1;
}
safefree(buf);
return 0;
}
/*
* Read in a "line" from the socket. It might take a few loops through
* the read sequence. The full string is allocate off the heap and stored
* at the whole_buffer pointer. The caller needs to free the memory when
* it is no longer in use. The returned line is NULL terminated.
*
* Returns the length of the buffer on success (not including the NULL
* termination), 0 if the socket was closed, and -1 on all other errors.
*/
#define SEGMENT_LEN (512)
#define MAXIMUM_BUFFER_LENGTH (128 * 1024)
ssize_t
readline(int fd, char **whole_buffer)
{
ssize_t whole_buffer_len;
char buffer[SEGMENT_LEN];
char *ptr;
ssize_t ret;
ssize_t diff;
struct read_lines_s {
char *data;
size_t len;
struct read_lines_s *next;
};
struct read_lines_s *first_line, *line_ptr;
first_line = safecalloc(sizeof(struct read_lines_s), 1);
if (!first_line)
return -ENOMEM;
line_ptr = first_line;
whole_buffer_len = 0;
for (;;) {
ret = recv(fd, buffer, SEGMENT_LEN, MSG_PEEK);
if (ret <= 0)
goto CLEANUP;
ptr = memchr(buffer, '\n', ret);
if (ptr)
diff = ptr - buffer + 1;
else
diff = ret;
whole_buffer_len += diff;
/*
* Don't allow the buffer to grow without bound. If we
* get to more than MAXIMUM_BUFFER_LENGTH close.
*/
if (whole_buffer_len > MAXIMUM_BUFFER_LENGTH) {
ret = -ERANGE;
goto CLEANUP;
}
line_ptr->data = safemalloc(diff);
if (!line_ptr->data) {
ret = -ENOMEM;
goto CLEANUP;
}
recv(fd, line_ptr->data, diff, 0);
line_ptr->len = diff;
if (ptr) {
line_ptr->next = NULL;
break;
}
line_ptr->next = safecalloc(sizeof(struct read_lines_s), 1);
if (!line_ptr->next) {
ret = -ENOMEM;
goto CLEANUP;
}
line_ptr = line_ptr->next;
}
*whole_buffer = safemalloc(whole_buffer_len + 1);
if (!*whole_buffer) {
ret = -ENOMEM;
goto CLEANUP;
}
*(*whole_buffer + whole_buffer_len) = '\0';
whole_buffer_len = 0;
line_ptr = first_line;
while (line_ptr) {
memcpy(*whole_buffer + whole_buffer_len, line_ptr->data,
line_ptr->len);
whole_buffer_len += line_ptr->len;
line_ptr = line_ptr->next;
}
ret = whole_buffer_len;
CLEANUP:
do {
line_ptr = first_line->next;
if (first_line->data)
safefree(first_line->data);
safefree(first_line);
first_line = line_ptr;
} while (first_line);
return ret;
}
|
