/* tinyproxy - A fast light-weight HTTP proxy
* Copyright (C) 2002, 2004 Robert James Kaes <rjkaes@users.sourceforge.net>
*
* 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.
*/
/* 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.
*/
#include "main.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 ((size_t) 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 = (char *) 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 && (size_t) 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 = (char *) 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 =
(struct read_lines_s *) 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 = (char *) 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 = (char *) 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 =
(struct read_lines_s *)
safecalloc (sizeof (struct read_lines_s), 1);
if (!line_ptr->next) {
ret = -ENOMEM;
goto CLEANUP;
}
line_ptr = line_ptr->next;
}
*whole_buffer = (char *) 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;
}
/*
* Convert the network address into either a dotted-decimal or an IPv6
* hex string.
*/
char *get_ip_string (struct sockaddr *sa, char *buf, size_t buflen)
{
assert (sa != NULL);
assert (buf != NULL);
assert (buflen != 0);
buf[0] = '\0'; /* start with an empty string */
switch (sa->sa_family) {
case AF_INET:
{
struct sockaddr_in *sa_in = (struct sockaddr_in *) sa;
inet_ntop (AF_INET, &sa_in->sin_addr, buf, buflen);
break;
}
case AF_INET6:
{
struct sockaddr_in6 *sa_in6 =
(struct sockaddr_in6 *) sa;
inet_ntop (AF_INET6, &sa_in6->sin6_addr, buf, buflen);
break;
}
default:
/* no valid family */
return NULL;
}
return buf;
}
/*
* Convert a numeric character string into an IPv6 network address
* (in binary form.) The function works just like inet_pton(), but it
* will accept both IPv4 and IPv6 numeric addresses.
*
* Returns the same as inet_pton().
*/
int full_inet_pton (const char *ip, void *dst)
{
char buf[24], tmp[24]; /* IPv4->IPv6 = ::FFFF:xxx.xxx.xxx.xxx\0 */
int n;
assert (ip != NULL && strlen (ip) != 0);
assert (dst != NULL);
/*
* Check if the string is an IPv4 numeric address. We use the
* older inet_aton() call since it handles more IPv4 numeric
* address formats.
*/
n = inet_aton (ip, (struct in_addr *) dst);
if (n == 0) {
/*
* Simple case: "ip" wasn't an IPv4 numeric address, so
* try doing the conversion as an IPv6 address. This
* will either succeed or fail, but we can't do any
* more processing anyway.
*/
return inet_pton (AF_INET6, ip, dst);
}
/*
* "ip" was an IPv4 address, so we need to convert it to
* an IPv4-mapped IPv6 address and do the conversion
* again to get the IPv6 network structure.
*
* We convert the IPv4 binary address back into the
* standard dotted-decimal format using inet_ntop()
* so we can be sure that inet_pton will accept the
* full string.
*/
snprintf (buf, sizeof (buf), "::ffff:%s",
inet_ntop (AF_INET, dst, tmp, sizeof (tmp)));
return inet_pton (AF_INET6, buf, dst);
}