On 10/08/2013 09:42 PM, Eduardo Otubo wrote:
v3: The options for blacklist in the command line also checkes the
existence of "-netdev tap", leaving a warning message in a positive
case.
New command line options for the seccomp blacklist feature:
$ qemu -sandbox on[,strict=<on|off>]
The strict parameter will turn on or off the new system call blacklist
Signed-off-by: Eduardo Otubo <ot...@linux.vnet.ibm.com>
---
qemu-options.hx | 8 +++++---
vl.c | 17 ++++++++++++++++-
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/qemu-options.hx b/qemu-options.hx
index d15338e..05485e1 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2978,13 +2978,15 @@ Old param mode (ARM only).
ETEXI
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
- "-sandbox <arg> Enable seccomp mode 2 system call filter (default
'off').\n",
+ "-sandbox <arg> Enable seccomp mode 2 system call filter (default
'off').\n"
+ "-sandbox on[,strict=<arg>]\n"
+ " Enable seccomp mode 2 system call second level filter (default
'off').\n",
QEMU_ARCH_ALL)
STEXI
-@item -sandbox @var{arg}
+@item -sandbox @var{arg}[,strict=@var{value}]
@findex -sandbox
Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering
and 'off' will
-disable it. The default is 'off'.
+disable it. The default is 'off'. 'strict=on' will enable second level filter
(default is 'off').
ETEXI
DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig,
diff --git a/vl.c b/vl.c
index ee95674..ffdf460 100644
--- a/vl.c
+++ b/vl.c
@@ -330,6 +330,9 @@ static QemuOptsList qemu_sandbox_opts = {
{
.name = "enable",
.type = QEMU_OPT_BOOL,
+ },{
+ .name = "strict",
+ .type = QEMU_OPT_STRING,
},
{ /* end of list */ }
},
@@ -1032,6 +1035,7 @@ static int bt_parse(const char *opt)
static int parse_sandbox(QemuOpts *opts, void *opaque)
{
+ const char *strict_value = NULL;
/* FIXME: change this to true for 1.3 */
if (qemu_opt_get_bool(opts, "enable", false)) {
#ifdef CONFIG_SECCOMP
@@ -1040,6 +1044,17 @@ static int parse_sandbox(QemuOpts *opts, void *opaque)
"failed to install seccomp syscall filter in the
kernel");
return -1;
}
+
+ strict_value = qemu_opt_get(opts, "strict");
+
+ if (!tap_enabled)
.------^
Just spotted tha I erased this open brace in one of my rebases.
+ if (strict_value && !strcmp(strict_value, "on")) {
+ enable_blacklist = true;
+ }
+ } else {
+ fprintf(stderr, "Warning: seccomp syscall second level filter \"-sandbox
on,strict=on\" "
+ "cannot work together with \"-netdev tap\". Disabling
it.\n");
+ }
#else
qerror_report(ERROR_CLASS_GENERIC_ERROR,
"sandboxing request but seccomp is not compiled into this
build");
@@ -1769,7 +1784,7 @@ void vm_state_notify(int running, RunState state)
static void install_seccomp_blacklist(void)
{
- if (enable_blacklist && !tap_enabled) {
+ if (enable_blacklist) {
if (seccomp_start(BLACKLIST) < 0) {
qerror_report(ERROR_CLASS_GENERIC_ERROR,
"failed to install seccomp syscall second level filter
in the kernel");
--
Eduardo Otubo
IBM Linux Technology Center
