Reorganised the source tree. We now have src/ with a couple of subdirs:

* daemon/ - Contains the files specific to the polypaudio daemon.
 * modules/ - All loadable modules.
 * polyp/ - Files that are part of the public, application interface or
   are only used in libpolyp.
 * polypcore/ - All other shared files.
 * tests/ - Test programs.
 * utils/ - Utility programs.


git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@487 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/daemon/caps.c

@@ -0,0 +1,131 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+ 
+  polypaudio 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 Lesser General Public License
+  along with polypaudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#ifdef HAVE_SYS_CAPABILITY_H
+#include <sys/capability.h>
+#endif
+
+#include <polypcore/log.h>
+#include "caps.h"
+
+#ifdef HAVE_GETUID
+
+/* Drop root rights when called SUID root */
+void pa_drop_root(void) {
+    uid_t uid = getuid();
+    
+    if (uid == 0 || geteuid() != 0)
+        return;
+
+    pa_log_info(__FILE__": dropping root rights.\n");
+
+#if defined(HAVE_SETRESUID)
+    setresuid(uid, uid, uid);
+#elif defined(HAVE_SETREUID)
+    setreuid(uid, uid);
+#else
+    setuid(uid);
+    seteuid(uid);
+#endif
+}
+
+#else
+
+void pa_drop_root(void) {
+}
+
+#endif
+
+#ifdef HAVE_SYS_CAPABILITY_H
+
+/* Limit capabilities set to CAPSYS_NICE */
+int pa_limit_caps(void) {
+    int r = -1;
+    cap_t caps;
+    cap_value_t nice_cap = CAP_SYS_NICE;
+
+    caps = cap_init();
+    assert(caps);
+
+    cap_clear(caps);
+
+    cap_set_flag(caps, CAP_EFFECTIVE, 1, &nice_cap, CAP_SET);
+    cap_set_flag(caps, CAP_PERMITTED, 1, &nice_cap, CAP_SET);
+
+    if (cap_set_proc(caps) < 0)
+        goto fail;
+
+    pa_log_info(__FILE__": dropped capabilities successfully.\n"); 
+    
+    r = 0;
+
+fail:
+    cap_free (caps);
+    
+    return r;
+}
+
+/* Drop all capabilities, effectively becoming a normal user */
+int pa_drop_caps(void) {
+    cap_t caps;
+    int r = -1;
+
+    caps = cap_init();
+    assert(caps);
+
+    cap_clear(caps);
+
+    if (cap_set_proc(caps) < 0) {
+        pa_log(__FILE__": failed to drop capabilities: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    r = 0;
+
+fail:
+    cap_free (caps);
+    
+    return r;
+}
+
+#else
+
+/* NOOPs in case capabilities are not available. */
+int pa_limit_caps(void) {
+    return 0;
+}
+
+int pa_drop_caps(void) {
+    pa_drop_root();
+    return 0;
+}
+
+#endif
+