networking/httpd_ssi.c: new example CGI handler

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

networking/httpd_indexcgi.c

@@ -28,7 +28,8 @@ httpd_indexcgi.c -o index.cgi
 /* We don't use printf, as it pulls in >12 kb of code from uclibc (i386). */
 /* Currently malloc machinery is the biggest part of libc we pull in. */
 /* We have only one realloc and one strdup, any idea how to do without? */
-/* Size (i386, approximate):
+
+/* Size (i386, static uclibc, approximate):
  *   text    data     bss     dec     hex filename
  *  13036      44    3052   16132    3f04 index.cgi
  *   2576       4    2048    4628    1214 index.cgi.o
@@ -210,7 +211,7 @@ static void fmt_04u(/*char *dst,*/ unsigned n)
 	fmt_02u(n % 100);
 }
 
-int main(void)
+int main(int argc, char *argv[])
 {
 	dir_list_t *dir_list;
 	dir_list_t *cdir;
@@ -225,6 +226,7 @@ int main(void)
 	QUERY_STRING = getenv("QUERY_STRING");
 	if (!QUERY_STRING
 	 || QUERY_STRING[0] != '/'
+	 || strstr(QUERY_STRING, "//")
 	 || strstr(QUERY_STRING, "/../")
 	 || strcmp(strrchr(QUERY_STRING, '/'), "/..") == 0
 	) {

networking/httpd_ssi.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2009 Denys Vlasenko <vda.linux@googlemail.com>
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+
+/*
+ * This program is a CGI application. It processes server-side includes:
+ * <!--#include file="file.html" -->
+ */
+
+/* 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
+   8931     164   68552   77647   12f4f httpd_ssi
+*/
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <time.h>
+
+static char line[64 * 1024];
+
+/*
+ * Currently only handles directives which are alone on the line
+ */
+static void process_includes(const char *filename)
+{
+	FILE *fp = fopen(filename, "r");
+	if (!fp)
+		exit(1);
+
+#define INCLUDE "<!--#include file=\""
+	while (fgets(line, sizeof(line), fp)) {
+		char *closing_dq;
+
+		/* FIXME: output text leading to INCLUDE first */
+		if (strncmp(line, INCLUDE, sizeof(INCLUDE)-1) != 0
+		 || (closing_dq = strchr(line + sizeof(INCLUDE)-1, '"')) == NULL
+		/* or strstr(line + sizeof(INCLUDE)-1, "\" -->")? */
+		) {
+			fputs(line, stdout);
+			continue;
+		}
+		*closing_dq = '\0';
+		/* FIXME: (1) are relative paths ok?
+		 * (2) if we include a/1.htm and it includes b/2.htm,
+		 * do we need to insert a/b/2.htm or b/2.htm?
+		 * IOW, do we need to "cd $dirname"?
+		 */
+		process_includes(line + sizeof(INCLUDE)-1);
+		/* FIXME: this should be the tail of line after --> */
+		putchar('\n');
+	}
+}
+
+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
+	 */
+	printf(
+		/* "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"
+	);
+	process_includes(argv[1]);
+	return 0;
+}