begin basic sandboxing with qssb

.gitmodules

@@ -1,3 +1,7 @@
 [submodule "git"]
 	url = https://git.kernel.org/pub/scm/git/git.git
 	path = git
+
+[submodule "qssb"]
+	path = qssb
+	url = https://git.quitesimple.org/qssb.h/

cgit.c

@@ -16,7 +16,7 @@
 #include "ui-blob.h"
 #include "ui-summary.h"
 #include "scan-tree.h"
-
+#include "qssb/qssb.h"
 const char *cgit_version = CGIT_VERSION;
 
 __attribute__((constructor))
@@ -1046,6 +1046,30 @@ static int calc_ttl(void)
 	return ctx.cfg.cache_repo_ttl;
 }
 
+void enable_sandbox()
+{
+	struct qssb_policy *policy = qssb_init_policy();
+
+	size_t allowed_paths_length = cgit_repolist.count+2;
+	char **allowed_paths = malloc(sizeof(char *) * allowed_paths_length);
+	allowed_paths[0] = "/dev/"; //TODO: drop this once qssb can create some minimal /dev itself
+	for(int i = 0; i < cgit_repolist.count; i++)
+	{
+		struct cgit_repo *current = &cgit_repolist.repos[i];
+		allowed_paths[i+1] = current->path;
+	}
+	allowed_paths[allowed_paths_length-1] = NULL;
+	policy->readonly_paths = allowed_paths;
+	if(qssb_enable_policy(policy) != 0)
+	{
+		fprintf(stderr, "%s", "Failed to init sandbox\n");
+		exit(EXIT_FAILURE);
+	}
+
+	free(allowed_paths);
+	qssb_free_policy(policy);
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	const char *path;
@@ -1064,6 +1088,8 @@ int cmd_main(int argc, const char **argv)
 	ctx.repo = NULL;
 	http_parse_querystring(ctx.qry.raw, querystring_cb);
 
+	enable_sandbox();
+
 	/* If virtual-root isn't specified in cgitrc, lets pretend
 	 * that virtual-root equals SCRIPT_NAME, minus any possibly
 	 * trailing slashes.

qssb

@@ -0,0 +1 @@
+Subproject commit 1635ffce087130ca25f97a31841c9d28f7808b87