[tracker] libtracker-common: Add tracker-seccomp from the libtracker-miners library

[Sam Thursfield <sthursfield src gnome org>]

commit 9afd9afc67a2ccbe4d8eee59a4b9be796e794f2d
Author: Sam Thursfield <sam thursfield codethink co uk>
Date:   Thu Oct 19 20:28:57 2017 +0100

    libtracker-common: Add tracker-seccomp from the libtracker-miners library
    
    This module is only used in the tracker-miners repo. However, when
    building this repo as a Meson subproject of tracker-miners.git, we
    can only build one version of libtracker-common so we need to have
    it present in our version.

 src/libtracker-common/meson.build       |    1 +
 src/libtracker-common/tracker-seccomp.c |  228 +++++++++++++++++++++++++++++++
 src/libtracker-common/tracker-seccomp.h |   35 +++++
 3 files changed, 264 insertions(+), 0 deletions(-)
---
diff --git a/src/libtracker-common/meson.build b/src/libtracker-common/meson.build
index c9a1def..b0411cc 100644
--- a/src/libtracker-common/meson.build
+++ b/src/libtracker-common/meson.build
@@ -26,6 +26,7 @@ tracker_common_sources = [
   'tracker-locale.c',
   'tracker-parser-utils.c',
   'tracker-language.c',
+  'tracker-seccomp.c',
   enums[0], enums[1],
   tracker_common_parser_sha1_header,
 ]
diff --git a/src/libtracker-common/tracker-seccomp.c b/src/libtracker-common/tracker-seccomp.c
new file mode 100644
index 0000000..ec873f5
--- /dev/null
+++ b/src/libtracker-common/tracker-seccomp.c
@@ -0,0 +1,228 @@
+/*
+ * Copyright (C) 2016, Red Hat Inc.
+ *
+ * This library 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 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA  02110-1301, USA.
+ */
+
+#include "config.h"
+
+#include "tracker-seccomp.h"
+
+#ifdef HAVE_LIBSECCOMP
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/prctl.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+
+#include <seccomp.h>
+
+#define ALLOW_RULE(call) G_STMT_START { \
+       int allow_rule_syscall_number = seccomp_syscall_resolve_name (G_STRINGIFY (call)); \
+       if (allow_rule_syscall_number == __NR_SCMP_ERROR || \
+           seccomp_rule_add (ctx, SCMP_ACT_ALLOW, allow_rule_syscall_number, 0) < 0) \
+               goto out; \
+} G_STMT_END
+
+#define ERROR_RULE(call, error) G_STMT_START { \
+       int error_rule_syscall_number = seccomp_syscall_resolve_name (G_STRINGIFY (call)); \
+       if (error_rule_syscall_number == __NR_SCMP_ERROR || \
+           seccomp_rule_add (ctx, SCMP_ACT_ERRNO (error), error_rule_syscall_number, 0) < 0) \
+               goto out; \
+} G_STMT_END
+
+gboolean
+tracker_seccomp_init (void)
+{
+       scmp_filter_ctx ctx;
+
+       ctx = seccomp_init (SCMP_ACT_TRAP);
+       if (ctx == NULL)
+               return FALSE;
+
+       /* Memory management */
+       ALLOW_RULE (brk);
+       ALLOW_RULE (mmap);
+       ALLOW_RULE (mmap2);
+       ALLOW_RULE (munmap);
+       ALLOW_RULE (mremap);
+       ALLOW_RULE (mprotect);
+       ALLOW_RULE (madvise);
+       ERROR_RULE (mlock, EPERM);
+       ERROR_RULE (mlock2, EPERM);
+       ERROR_RULE (munlock, EPERM);
+       ERROR_RULE (mlockall, EPERM);
+       ERROR_RULE (munlockall, EPERM);
+       /* Process management */
+       ALLOW_RULE (exit_group);
+       ALLOW_RULE (getuid);
+       ALLOW_RULE (getuid32);
+       ALLOW_RULE (geteuid);
+       ALLOW_RULE (geteuid32);
+       ALLOW_RULE (getppid);
+       ALLOW_RULE (gettid);
+       ALLOW_RULE (getpid);
+       ALLOW_RULE (exit);
+       ALLOW_RULE (getrusage);
+       ALLOW_RULE (getrlimit);
+       /* Basic filesystem access */
+       ALLOW_RULE (fstat);
+       ALLOW_RULE (fstat64);
+       ALLOW_RULE (stat);
+       ALLOW_RULE (stat64);
+       ALLOW_RULE (statfs);
+       ALLOW_RULE (statfs64);
+       ALLOW_RULE (lstat);
+       ALLOW_RULE (lstat64);
+       ALLOW_RULE (access);
+       ALLOW_RULE (getdents);
+       ALLOW_RULE (getdents64);
+       ALLOW_RULE (readlink);
+       ALLOW_RULE (readlinkat);
+       ALLOW_RULE (utime);
+       ALLOW_RULE (time);
+       ALLOW_RULE (fsync);
+       ALLOW_RULE (umask);
+       /* Processes and threads */
+       ALLOW_RULE (clone);
+       ALLOW_RULE (futex);
+       ALLOW_RULE (set_robust_list);
+       ALLOW_RULE (rt_sigaction);
+       ALLOW_RULE (rt_sigprocmask);
+       ALLOW_RULE (sched_yield);
+       ALLOW_RULE (sched_getaffinity);
+       ALLOW_RULE (nanosleep);
+       ALLOW_RULE (waitid);
+       ALLOW_RULE (waitpid);
+       ALLOW_RULE (wait4);
+       /* Main loops */
+       ALLOW_RULE (poll);
+       ALLOW_RULE (ppoll);
+       ALLOW_RULE (fcntl);
+       ALLOW_RULE (fcntl64);
+       ALLOW_RULE (eventfd);
+       ALLOW_RULE (eventfd2);
+       ALLOW_RULE (pipe);
+       ALLOW_RULE (pipe2);
+       /* System */
+       ALLOW_RULE (uname);
+       ALLOW_RULE (sysinfo);
+       ALLOW_RULE (prctl);
+       ALLOW_RULE (getrandom);
+       ALLOW_RULE (clock_gettime);
+       ALLOW_RULE (clock_getres);
+       ALLOW_RULE (gettimeofday);
+       /* Descriptors */
+       ALLOW_RULE (close);
+       ALLOW_RULE (read);
+       ALLOW_RULE (pread64);
+       ALLOW_RULE (lseek);
+       ALLOW_RULE (_llseek);
+       ALLOW_RULE (fadvise64);
+       ALLOW_RULE (write);
+       ALLOW_RULE (writev);
+       ALLOW_RULE (dup);
+       ALLOW_RULE (dup2);
+       ALLOW_RULE (dup3);
+       /* Needed by some GStreamer modules doing crazy stuff, less
+        * scary thanks to the restriction below about sockets being
+        * local.
+        */
+       ALLOW_RULE (connect);
+       ALLOW_RULE (send);
+       ALLOW_RULE (sendto);
+       ALLOW_RULE (sendmsg);
+       ALLOW_RULE (recv);
+       ALLOW_RULE (recvmsg);
+       ALLOW_RULE (recvfrom);
+       ALLOW_RULE (getsockname);
+       ALLOW_RULE (getpeername);
+       ALLOW_RULE (shutdown);
+
+       /* Special requirements for socket/socketpair, only on AF_UNIX/AF_LOCAL */
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socket), 1,
+                             SCMP_CMP(0, SCMP_CMP_EQ, AF_UNIX)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socket), 1,
+                             SCMP_CMP(0, SCMP_CMP_EQ, AF_LOCAL)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socketpair), 1,
+                             SCMP_CMP(0, SCMP_CMP_EQ, AF_UNIX)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socketpair), 1,
+                             SCMP_CMP(0, SCMP_CMP_EQ, AF_LOCAL)) < 0)
+               goto out;
+
+       /* Special requirements for ioctl, allowed on stdout/stderr */
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(ioctl), 1,
+                             SCMP_CMP(0, SCMP_CMP_EQ, 1)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(ioctl), 1,
+                             SCMP_CMP(0, SCMP_CMP_EQ, 2)) < 0)
+               goto out;
+
+       /* Special requirements for open/openat, allow O_RDONLY calls,
+         * but fail if write permissions are requested.
+        */
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(open), 1,
+                             SCMP_CMP(1, SCMP_CMP_MASKED_EQ, O_WRONLY | O_RDWR, 0)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ERRNO (EACCES), SCMP_SYS(open), 1,
+                             SCMP_CMP(1, SCMP_CMP_MASKED_EQ, O_WRONLY, O_WRONLY)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ERRNO (EACCES), SCMP_SYS(open), 1,
+                             SCMP_CMP(1, SCMP_CMP_MASKED_EQ, O_RDWR, O_RDWR)) < 0)
+               goto out;
+
+       if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(openat), 1,
+                             SCMP_CMP(2, SCMP_CMP_MASKED_EQ, O_WRONLY | O_RDWR, 0)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ERRNO (EACCES), SCMP_SYS(openat), 1,
+                             SCMP_CMP(2, SCMP_CMP_MASKED_EQ, O_WRONLY, O_WRONLY)) < 0)
+               goto out;
+       if (seccomp_rule_add (ctx, SCMP_ACT_ERRNO (EACCES), SCMP_SYS(openat), 1,
+                             SCMP_CMP(2, SCMP_CMP_MASKED_EQ, O_RDWR, O_RDWR)) < 0)
+               goto out;
+
+       g_debug ("Loading seccomp rules.");
+
+       if (seccomp_load (ctx) >= 0)
+               return TRUE;
+
+out:
+       g_critical ("Failed to load seccomp rules.");
+       seccomp_release (ctx);
+       return FALSE;
+}
+
+#else /* HAVE_LIBSECCOMP */
+
+gboolean
+tracker_seccomp_init (void)
+{
+       g_warning ("No seccomp support compiled-in.");
+       return TRUE;
+}
+
+#endif /* HAVE_LIBSECCOMP */
diff --git a/src/libtracker-common/tracker-seccomp.h b/src/libtracker-common/tracker-seccomp.h
new file mode 100644
index 0000000..0e03330
--- /dev/null
+++ b/src/libtracker-common/tracker-seccomp.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2016, Red Hat Inc.
+ *
+ * This library 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 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA  02110-1301, USA.
+ */
+
+#ifndef __TRACKER_SECCOMP_H__
+#define __TRACKER_SECCOMP_H__
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+#if !defined (__LIBTRACKER_COMMON_INSIDE__) && !defined (TRACKER_COMPILATION)
+#error "only <libtracker-common/tracker-common.h> must be included directly."
+#endif
+
+gboolean tracker_seccomp_init (void);
+
+G_END_DECLS
+
+#endif /* __TRACKER_SECCOMP_H__ */