add preliminary cgi support, needs fixing for close handling

1 files changed, 115 insertions, 0 deletions

diff --git a/cgi.c b/cgi.c
new file mode 100644
index 0000000..cfd71fb
--- /dev/null
+++ b/cgi.c
@@ -0,0 +1,115 @@
+/*
+ * uhttpd - Tiny single-threaded httpd
+ *
+ *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
+ *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <libubox/blobmsg.h>
+#include "uhttpd.h"
+
+static LIST_HEAD(interpreters);
+
+void uh_interpreter_add(const char *ext, const char *path)
+{
+	struct interpreter *in;
+	char *new_ext, *new_path;
+
+	in = calloc_a(sizeof(*in),
+		&new_ext, strlen(ext) + 1,
+		&new_path, strlen(path) + 1);
+
+	in->ext = strcpy(new_ext, ext);
+	in->path = strcpy(new_path, path);
+	list_add_tail(&in->list, &interpreters);
+}
+
+static void cgi_main(struct client *cl, struct path_info *pi, int fd)
+{
+	struct interpreter *ip = pi->ip;
+	struct env_var *var;
+
+	dup2(fd, 0);
+	dup2(fd, 1);
+	close(fd);
+	clearenv();
+	setenv("PATH", conf.cgi_path, 1);
+
+	for (var = uh_get_process_vars(cl, pi); var->name; var++) {
+		if (!var->value)
+			continue;
+
+		setenv(var->name, var->value, 1);
+	}
+
+	chdir(pi->root);
+
+	if (ip)
+		execl(ip->path, ip->path, pi->phys, NULL);
+	else
+		execl(pi->phys, pi->phys, NULL);
+
+	printf("Status: 500 Internal Server Error\r\n\r\n"
+	       "Unable to launch the requested CGI program:\n"
+	       "  %s: %s\n", ip ? ip->path : pi->phys, strerror(errno));
+}
+
+static void cgi_handle_request(struct client *cl, const char *url, struct path_info *pi)
+{
+	unsigned int mode = S_IFREG | S_IXOTH;
+
+	if (!pi->ip && !((pi->stat.st_mode & mode) == mode)) {
+		uh_client_error(cl, 403, "Forbidden",
+				"You don't have permission to access %s on this server.",
+				url);
+		return;
+	}
+
+	if (!uh_create_process(cl, pi, cgi_main)) {
+		uh_client_error(cl, 500, "Internal Server Error",
+				"Failed to create CGI process: %s", strerror(errno));
+		return;
+	}
+
+	return;
+}
+
+static bool check_cgi_path(struct path_info *pi, const char *url)
+{
+	struct interpreter *ip;
+	const char *path = pi->phys;
+	int path_len = strlen(path);
+
+	list_for_each_entry(ip, &interpreters, list) {
+		int len = strlen(ip->ext);
+
+		if (len >= path_len)
+			continue;
+
+		if (strcmp(path + path_len - len, ip->ext) != 0)
+			continue;
+
+		pi->ip = ip;
+		return true;
+	}
+
+	pi->ip = NULL;
+	return uh_path_match(conf.cgi_prefix, url);
+}
+
+struct dispatch_handler cgi_dispatch = {
+	.check_path = check_cgi_path,
+	.handle_request = cgi_handle_request,
+};