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/* 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 "tinyproxy.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, 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;
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';
if (!
(varval =
lookup_variable(connptr,
varstart)))
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, char *message)
{
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;
char *fallback_error =
"<html><head><title>%s</title></head>"
"<body><blockquote><i>%s %s</i><br>"
"The page you requested was unavailable. The error code is listed "
"below. In addition, the HTML file which has been configured as the "
"page to be displayed when an error of this type was unavailable, "
"with the error code %d (%s). Please contact your administrator."
"<center>%s</center>" "</body></html>" "\r\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")))
return (write_message(connptr->client_fd, fallback_error,
connptr->error_string,
PACKAGE, VERSION,
errno, strerror(errno),
connptr->error_string));
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, char *key, 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 (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);
ADD_VAR_RET("version", VERSION);
ADD_VAR_RET("package", PACKAGE);
ADD_VAR_RET("website", "http://tinyproxy.banu.com/");
global_time = time(NULL);
strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT",
gmtime(&global_time));
ADD_VAR_RET("date", timebuf);
return (0);
}
/*
* Add the error information to the conn structure.
*/
int
indicate_http_error(struct conn_s *connptr, int number, 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));
}
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