/* tinyproxy - A fast light-weight HTTP proxy
* Copyright (C) 2003 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.
*/
/* See 'http-message.h' for detailed information. */
#include "common.h"
#include "heap.h"
#include "http-message.h"
#include "network.h"
/*
* Package up an HTTP message into a nice little structure. As you can
* see this structure doesn't actually store any allocated strings;
* therefore, the caller must free any memory referenced by this struct.
* Also, the caller MUST NOT free the memory while the structure is
* still in use---bad things would happen.
*/
struct http_message_s {
/* Response string and code supplied on the HTTP status line */
struct {
const char *string;
int code;
} response;
/*
* A group of headers to be sent with this message. Right now
* the strings are referenced through pointers in an array.
* I might change this to a vector in the future.
*/
struct {
const char **strings;
unsigned int total;
unsigned int used;
} headers;
/* Body of the message (most likely an HTML message) */
struct {
const char *text;
size_t length;
} body;
};
/*
* Check if the HTTP message is validly formed. This is the one odd-ball
* function. It returns 0 if the message is invalid; otherwise, a positive
* number is returned. Useful for if() tests and assert() tests.
*/
static int is_http_message_valid (http_message_t msg)
{
if (msg == NULL)
return 0;
if (msg->headers.strings == NULL)
return 0;
if (msg->response.string == NULL)
return 0;
if (msg->response.code < 1 || msg->response.code > 999)
return 0;
return 1;
}
/* Initially allocate space for 128 headers */
#define NUMBER_OF_HEADERS 128
/*
* Allocate a new http_message structure on the heap.
* If memory could not be allocated, return a NULL.
*/
http_message_t
http_message_create (int response_code, const char *response_string)
{
http_message_t msg;
int ret;
msg =
(struct http_message_s *) safecalloc (1,
sizeof (struct
http_message_s));
if (msg == NULL)
return NULL;
msg->headers.strings = (const char **) safecalloc (NUMBER_OF_HEADERS,
sizeof (char *));
if (msg->headers.strings == NULL) {
safefree (msg);
return NULL;
}
msg->headers.total = NUMBER_OF_HEADERS;
/* Store the HTTP response information in the structure */
ret = http_message_set_response (msg, response_code, response_string);
if (IS_HTTP_MSG_ERROR (ret)) {
safefree (msg->headers.strings);
safefree (msg);
return NULL;
}
return msg;
}
/*
* Free up the space associated with this HTTP message structure.
* This DOES NOT free the pointers stored in this structure. That memory
* is the responsibility of the caller.
*/
int http_message_destroy (http_message_t msg)
{
assert (msg != NULL);
assert (msg->headers.strings != NULL);
/* Check for valid arguments */
if (msg == NULL)
return -EFAULT;
if (msg->headers.strings != NULL)
safefree (msg->headers.strings);
safefree (msg);
return 0;
}
/*
* Set the HTTP response information for this structure. The response_string
* must be a NUL ('\0') terminated C string.
*/
int
http_message_set_response (http_message_t msg,
int response_code, const char *response_string)
{
/* Check for valid arguments */
if (msg == NULL)
return -EFAULT;
if (response_code < 1 || response_code > 999)
return -EINVAL;
if (response_string == NULL)
return -EINVAL;
if (strlen (response_string) == 0)
return -EINVAL;
msg->response.code = response_code;
msg->response.string = response_string;
return 0;
}
/*
* Set the HTTP message body.
*/
int http_message_set_body (http_message_t msg, const char *body, size_t len)
{
/* Check for valid arguments */
if (msg == NULL)
return -EFAULT;
if (body == NULL)
return -EINVAL;
if (len == 0)
return -EINVAL;
msg->body.text = body;
msg->body.length = len;
return 0;
}
/*
* Add headers to the structure.
*/
int
http_message_add_headers (http_message_t msg, const char **headers,
unsigned int num_headers)
{
const char **new_headers;
unsigned int i;
/* Check for valid arguments */
if (msg == NULL)
return -EFAULT;
if (headers == NULL)
return -EINVAL;
/*
* If the number of headers to add is greater than the space
* available, reallocate the memory.
*/
if (msg->headers.used + num_headers > msg->headers.total) {
new_headers =
(const char **) safecalloc (msg->headers.total * 2,
sizeof (char *));
if (new_headers == NULL)
return -ENOMEM;
/* Copy the array */
for (i = 0; i != msg->headers.used; ++i)
new_headers[i] = msg->headers.strings[i];
/* Remove the old array and replace it with the new array */
safefree (msg->headers.strings);
msg->headers.strings = new_headers;
msg->headers.total *= 2;
}
/*
* Add the new headers to the structure
*/
for (i = 0; i != num_headers; ++i)
msg->headers.strings[i + msg->headers.used] = headers[i];
msg->headers.used += num_headers;
return 0;
}
/*
* Send the completed HTTP message via the supplied file descriptor.
*/
int http_message_send (http_message_t msg, int fd)
{
char timebuf[30];
time_t global_time;
unsigned int i;
assert (is_http_message_valid (msg));
/* Check for valid arguments */
if (msg == NULL)
return -EFAULT;
if (fd < 1)
return -EBADF;
if (!is_http_message_valid (msg))
return -EINVAL;
/* Write the response line */
write_message (fd, "HTTP/1.0 %d %s\r\n",
msg->response.code, msg->response.string);
/* Go through all the headers */
for (i = 0; i != msg->headers.used; ++i)
write_message (fd, "%s\r\n", msg->headers.strings[i]);
/* Output the date */
global_time = time (NULL);
strftime (timebuf, sizeof (timebuf), "%a, %d %b %Y %H:%M:%S GMT",
gmtime (&global_time));
write_message (fd, "Date: %s\r\n", timebuf);
/* Output the content-length */
write_message (fd, "Content-length: %u\r\n", msg->body.length);
/* Write the separator between the headers and body */
safe_write (fd, "\r\n", 2);
/* If there's a body, send it! */
if (msg->body.length > 0)
safe_write (fd, msg->body.text, msg->body.length);
return 0;
}