busybox/networking/httpd_ssi.c

171 lines
4.1 KiB
C
Raw Normal View History

/*
* Copyright (c) 2009 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
/*
* This program is a CGI application. It processes server-side includes:
* <!--#include file="file.html" -->
*
* Usage: put these lines in httpd.conf:
*
* *.html:/bin/httpd_ssi
* *.htm:/bin/httpd_ssi
*/
/* Build a-la
i486-linux-uclibc-gcc \
-static -static-libgcc \
-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 \
-Wall -Wshadow -Wwrite-strings -Wundef -Wstrict-prototypes -Werror \
-Wold-style-definition -Wdeclaration-after-statement -Wno-pointer-sign \
-Wmissing-prototypes -Wmissing-declarations \
-Os -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer \
-ffunction-sections -fdata-sections -fno-guess-branch-probability \
-funsigned-char \
-falign-functions=1 -falign-jumps=1 -falign-labels=1 -falign-loops=1 \
-march=i386 -mpreferred-stack-boundary=2 \
-Wl,-Map -Wl,link.map -Wl,--warn-common -Wl,--sort-common -Wl,--gc-sections \
httpd_ssi.c -o httpd_ssi
*/
/* Size (i386, static uclibc, approximate):
* text data bss dec hex filename
* 9487 160 68552 78199 13177 httpd_ssi
*
* Note: it wouldn't be too hard to get rid of stdio and strdup,
* (especially that fgets() mangles NULs...)
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <dirent.h>
#include <time.h>
static char* skip_whitespace(char *s)
{
while (*s == ' ' || *s == '\t') ++s;
return s;
}
static char line[64 * 1024];
static void process_includes(const char *filename)
{
int curdir_fd;
char *end;
FILE *fp = fopen(filename, "r");
if (!fp)
exit(1);
/* Ensure that nested includes are relative:
* if we include a/1.htm and it includes b/2.htm,
* we need to include a/b/2.htm, not b/2.htm
*/
curdir_fd = -1;
end = strrchr(filename, '/');
if (end) {
curdir_fd = open(".", O_RDONLY);
/* *end = '\0' would mishandle "/file.htm" */
end[1] = '\0';
chdir(filename);
}
#define INCLUDE "<!--#include"
while (fgets(line, sizeof(line), fp)) {
unsigned preceding_len;
char *include_directive;
include_directive = strstr(line, INCLUDE);
if (!include_directive) {
fputs(line, stdout);
continue;
}
preceding_len = include_directive - line;
if (memchr(line, '\"', preceding_len)
|| memchr(line, '\'', preceding_len)
) {
/* INCLUDE string may be inside "str" or 'str',
* ignore it */
fputs(line, stdout);
continue;
}
/* Small bug: we accept #includefile="file" too */
include_directive = skip_whitespace(include_directive + sizeof(INCLUDE)-1);
if (strncmp(include_directive, "file=\"", 6) != 0) {
/* "<!--#include virtual=..."? - not supported */
fputs(line, stdout);
continue;
}
include_directive += 6; /* now it points to file name */
end = strchr(include_directive, '\"');
if (!end) {
fputs(line, stdout);
continue;
}
/* We checked that this is a valid include directive */
/* Print everything before directive */
if (preceding_len) {
line[preceding_len] = '\0';
fputs(line, stdout);
}
/* Save everything after directive */
*end++ = '\0';
end = strchr(end, '>');
if (end)
end = strdup(end + 1);
/* FIXME:
* (1) are relative paths with /../ etc ok?
* (2) what to do with absolute paths?
* are they relative to doc root or to real root?
*/
process_includes(include_directive);
/* Print everything after directive */
if (end) {
fputs(end, stdout);
free(end);
}
}
if (curdir_fd >= 0)
fchdir(curdir_fd);
fclose(fp);
}
int main(int argc, char **argv)
{
if (!argv[1])
return 1;
/* Seen from busybox.net's Apache:
* HTTP/1.1 200 OK
* Date: Thu, 10 Sep 2009 18:23:28 GMT
* Server: Apache
* Accept-Ranges: bytes
* Connection: close
* Content-Type: text/html
*/
fputs(
/* "Date: Thu, 10 Sep 2009 18:23:28 GMT\r\n" */
/* "Server: Apache\r\n" */
/* "Accept-Ranges: bytes\r\n" - do we really accept bytes?! */
"Connection: close\r\n"
"Content-Type: text/html\r\n"
"\r\n",
stdout
);
process_includes(argv[1]);
return 0;
}