mkdir support in profile files

1 files changed, 70 insertions, 0 deletions

diff --git a/src/firejail/fs_mkdir.c b/src/firejail/fs_mkdir.c
new file mode 100644
index 000000000..7c2b108c6
--- /dev/null
+++ b/src/firejail/fs_mkdir.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2014-2016 Firejail Authors
+ *
+ * This file is part of firejail project
+ *
+ * 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.
+ */
+#include "firejail.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <grp.h>
+ #include <sys/wait.h>
+ 
+void fs_mkdir(const char *name) {
+        // check directory name
+        invalid_filename(name);
+        char *expanded = expand_home(name, cfg.homedir);
+        if (strncmp(expanded, cfg.homedir, strlen(cfg.homedir)) != 0) {
+                fprintf(stderr, "Error: only directories in user home are supported by mkdir\n");
+                exit(1);
+        }
+
+        struct stat s;
+        if (stat(expanded, &s) == 0) {
+                // file exists, do nothing
+                goto doexit;
+        }
+
+        // fork a process, drop privileges, and create the directory
+        // no error recovery will be attempted
+        pid_t child = fork();
+        if (child < 0)
+                errExit("fork");
+        if (child == 0) {
+                if (arg_debug)
+                        printf("Create %s directory\n", expanded);
+                
+                // drop privileges
+                if (setgroups(0, NULL) < 0)
+                        errExit("setgroups");
+                if (setgid(getgid()) < 0)
+                        errExit("setgid/getgid");
+                if (setuid(getuid()) < 0)
+                        errExit("setuid/getuid");
+                
+                // create directory
+                if (mkdir(expanded, 0755) == -1)
+                        fprintf(stderr, "Warning: cannot create %s directory\n", expanded);
+                exit(0);
+        }
+        
+        // wait for the child to finish
+        waitpid(child, NULL, 0);
+
+doexit:
+        free(expanded);
+}