Gianni Tedesco
2010-Sep-01 15:59 UTC
[Xen-devel] [PATCH,v5]: xl: randomly generate UUID''s
Changes since v4:
- Really fix it for NetBSD? Define our own structure which is a byte
array. Only use uuid_is_nul and uuid_create which should be safe for
our portability purposes. Previous attempt at portability wrapper was
just wrong minded.
- Remove uuid_to_string since our approach is to use a couple of macros
for this
- License under LGPL in line with rest of libxl
Changes since v3:
- Fix LIBXL_UUID_BYTES on NetBSD. Note that the code assumes
uint8_t[16] to always be interchangeable with libxl_uuid_t.
- Return error messages when uuid_parse fails, spotted by Owen Smith
- Implement "uuid" parameter in xl and exit with an error if parse
fails
Changes since v2:
- Re-based to remove orthogonal concern of UUID string formatting fixed
in 22001:0b6f82eaaea9 "xl: make libxl_uuid2string internal to
libxenlight"
- Incorporated Christoph Egger''s suggestions
8<---------------------------------------------------------------
This patch converts xl to randomly generate UUID''s rather than using a
dodgy time-seeded PRNG. I have ignored various suggestions so far on
auto-generation of MAC addresses and left it as a topic for a future
patch to solve. In other words the behaviour stays the same it''s just
using a true random source. This patch also implements the "uuid"
config
file parameter in xl.
Signed-off-by: Gianni Tedesco <gianni.tedesco@citrix.com>
diff -r 573ddf5cc145 tools/libxl/Makefile
--- a/tools/libxl/Makefile Tue Aug 31 19:16:23 2010 +0100
+++ b/tools/libxl/Makefile Wed Sep 01 16:55:39 2010 +0100
@@ -16,6 +16,9 @@ CFLAGS += -I. -fPIC
CFLAGS += $(CFLAGS_libxenctrl) $(CFLAGS_libxenguest) $(CFLAGS_libxenstore)
$(CFLAGS_libblktapctl)
LIBS = $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest) $(LDLIBS_libxenstore)
$(LDLIBS_libblktapctl) $(UTIL_LIBS)
+ifeq ($(CONFIG_Linux),y)
+LIBS += -luuid
+endif
LIBXL_OBJS-y = osdeps.o libxl_paths.o libxl_bootloader.o
ifeq ($(LIBXL_BLKTAP),y)
diff -r 573ddf5cc145 tools/libxl/libxl.c
--- a/tools/libxl/libxl.c Tue Aug 31 19:16:23 2010 +0100
+++ b/tools/libxl/libxl.c Wed Sep 01 16:55:39 2010 +0100
@@ -131,7 +131,7 @@ int libxl_domain_make(libxl_ctx *ctx, li
*domid = -1;
/* Ultimately, handle is an array of 16 uint8_t, same as uuid */
- memcpy(handle, info->uuid, sizeof(xen_domain_handle_t));
+ libxl_uuid_copy((libxl_uuid *)handle, &info->uuid);
ret = xc_domain_create(ctx->xch, info->ssidref, handle, flags,
domid);
if (ret < 0) {
@@ -1506,8 +1506,8 @@ static int libxl_create_stubdom(libxl_ct
memset(&c_info, 0x00, sizeof(libxl_domain_create_info));
c_info.hvm = 0;
c_info.name = libxl_sprintf(&gc, "%s-dm",
_libxl_domid_to_name(&gc, info->domid));
- for (i = 0; i < 16; i++)
- c_info.uuid[i] = info->uuid[i];
+
+ libxl_uuid_copy(&c_info.uuid, &info->uuid);
memset(&b_info, 0x00, sizeof(libxl_domain_build_info));
b_info.max_vcpus = 1;
diff -r 573ddf5cc145 tools/libxl/libxl.h
--- a/tools/libxl/libxl.h Tue Aug 31 19:16:23 2010 +0100
+++ b/tools/libxl/libxl.h Wed Sep 01 16:55:39 2010 +0100
@@ -131,13 +131,7 @@
#include <xs.h>
#include <sys/wait.h> /* for pid_t */
-typedef uint8_t libxl_uuid[16];
-#define LIBXL_UUID_FMT
"%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
-#define LIBXL_UUID_BYTES(uuid) uuid[0], uuid[1], uuid[2], uuid[3], \
- uuid[4], uuid[5], uuid[6], uuid[7], \
- uuid[8], uuid[9], uuid[10], uuid[11], \
- uuid[12], uuid[13], uuid[14], uuid[15] \
-
+#include "libxl_uuid.h"
typedef uint8_t libxl_mac[6];
diff -r 573ddf5cc145 tools/libxl/libxl_uuid.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/libxl/libxl_uuid.h Wed Sep 01 16:55:39 2010 +0100
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2008,2010 Citrix Ltd.
+ *
+ * This program 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; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * 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 Lesser General Public License for more details.
+ */
+
+#ifndef __LIBXL_UUID_H__
+#define __LIBXL_UUID_H__
+
+#define LIBXL_UUID_FMT
"%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
+#define LIBXL__UUID_BYTES(uuid) uuid[0], uuid[1], uuid[2], uuid[3], \
+ uuid[4], uuid[5], uuid[6], uuid[7], \
+ uuid[8], uuid[9], uuid[10], uuid[11], \
+ uuid[12], uuid[13], uuid[14], uuid[15]
+
+#if defined(__linux__)
+
+#include <uuid/uuid.h>
+
+typedef struct {
+ uuid_t uuid;
+} libxl_uuid;
+
+#define LIBXL_UUID_BYTES(arg) LIBXL__UUID_BYTES(((uint8_t *)arg.uuid))
+
+static inline int libxl_uuid_is_nil(libxl_uuid *uuid)
+{
+ return uuid_is_null(uuid->uuid);
+}
+
+static inline void libxl_uuid_generate(libxl_uuid *uuid)
+{
+ uuid_generate(uuid->uuid);
+}
+
+static inline int libxl_uuid_from_string(libxl_uuid *uuid, const char *in)
+{
+ return uuid_parse(in, uuid->uuid);
+}
+
+static inline void libxl_uuid_copy(libxl_uuid *dst, libxl_uuid *src)
+{
+ uuid_copy(dst->uuid, src->uuid);
+}
+
+static inline void libxl_uuid_clear(libxl_uuid *uuid)
+{
+ uuid_clear(uuid->uuid);
+}
+
+static inline int libxl_uuid_compare(libxl_uuid *uuid1, libxl_uuid *uuid2)
+{
+ return uuid_compare(uuid1->uuid, uuid2->uuid);
+}
+
+static inline const uint8_t *libxl_uuid_bytearray(libxl_uuid *uuid)
+{
+ return uuid->uuid;
+}
+
+#elif defined(__NetBSD__)
+
+#include <uuid.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+
+#define LIBXL_UUID_BYTES(arg) LIBXL__UUID_BYTES(arg.uuid)
+
+typedef struct {
+ uint8_t uuid[16];
+} libxl_uuid;
+
+static inline int libxl_uuid_is_nil(libxl_uuid *uuid)
+{
+ uint32_t status;
+ return uuid_is_nil((uuid_t *)uuid->uuid, &status);
+}
+
+static inline void libxl_uuid_generate(libxl_uuid *uuid)
+{
+ uint32_t status;
+ uuid_create((uuid_t *)uuid->uuid, &status);
+ assert(status == uuid_s_ok);
+}
+
+#define LIBXL__UUID_PTRS(uuid) &uuid[0], &uuid[1], &uuid[2],
&uuid[3], \
+ &uuid[4], &uuid[5], &uuid[6],
&uuid[7], \
+ &uuid[8], &uuid[9],
&uuid[10],&uuid[11], \
+
&uuid[12],&uuid[13],&uuid[14],&uuid[15]
+static inline int libxl_uuid_from_string(libxl_uuid *uuid, const char *in)
+{
+ if ( sscanf(in, LIBXL_UUID_FMT, LIBXL__UUID_PTRS(uuid->uuid)) !=
sizeof(uuid->uuid) )
+ return -1;
+ return 0;
+}
+#undef LIBXL__UUID_PTRS
+
+static inline void libxl_uuid_copy(libxl_uuid *dst, libxl_uuid *src)
+{
+ memcpy(dst->uuid, src->uuid, sizeof(dst->uuid));
+}
+
+static inline void libxl_uuid_clear(libxl_uuid *uuid)
+{
+ memset(uuid->uuid, 0, sizeof(uuid->uuid));
+}
+
+static inline int libxl_uuid_compare(libxl_uuid *uuid1, libxl_uuid *uuid2)
+{
+ return memcmp(uuid1->uuid, uuid2->uuid, sizeof(uuid1->uuid));
+}
+
+static inline const uint8_t *libxl_uuid_bytearray(libxl_uuid *uuid)
+{
+ return uuid->uuid;
+}
+
+#else
+
+#error "Please update libxl_uuid.h for your OS"
+
+#endif
+
+#endif /* __LIBXL_UUID_H__ */
diff -r 573ddf5cc145 tools/libxl/xl.c
--- a/tools/libxl/xl.c Tue Aug 31 19:16:23 2010 +0100
+++ b/tools/libxl/xl.c Wed Sep 01 16:55:39 2010 +0100
@@ -74,8 +74,6 @@ int main(int argc, char **argv)
argc -= optind;
optind = 1;
- srand(time(0));
-
cspec = cmdtable_lookup(cmd);
if (cspec)
ret = cspec->cmd_impl(argc, argv);
diff -r 573ddf5cc145 tools/libxl/xl_cmdimpl.c
--- a/tools/libxl/xl_cmdimpl.c Tue Aug 31 19:16:23 2010 +0100
+++ b/tools/libxl/xl_cmdimpl.c Wed Sep 01 16:55:39 2010 +0100
@@ -286,19 +286,12 @@ static void init_build_info(libxl_domain
}
}
-static void random_uuid(libxl_uuid *uuid)
-{
- int i;
- for (i = 0; i < 16; i++)
- (*uuid)[i] = rand();
-}
-
static void init_dm_info(libxl_device_model_info *dm_info,
libxl_domain_create_info *c_info, libxl_domain_build_info *b_info)
{
memset(dm_info, ''\0'', sizeof(*dm_info));
- random_uuid(&dm_info->uuid);
+ libxl_uuid_generate(&dm_info->uuid);
dm_info->dom_name = c_info->name;
dm_info->device_model = "qemu-dm";
@@ -325,6 +318,11 @@ static void init_dm_info(libxl_device_mo
static void init_nic_info(libxl_device_nic *nic_info, int devnum)
{
+ const uint8_t *r;
+ libxl_uuid uuid;
+
+ libxl_uuid_generate(&uuid);
+ r = libxl_uuid_bytearray(&uuid);
memset(nic_info, ''\0'', sizeof(*nic_info));
nic_info->backend_domid = 0;
@@ -335,9 +333,9 @@ static void init_nic_info(libxl_device_n
nic_info->mac[0] = 0x00;
nic_info->mac[1] = 0x16;
nic_info->mac[2] = 0x3e;
- nic_info->mac[3] = 1 + (int) (0x7f * (rand() / (RAND_MAX + 1.0)));
- nic_info->mac[4] = 1 + (int) (0xff * (rand() / (RAND_MAX + 1.0)));
- nic_info->mac[5] = 1 + (int) (0xff * (rand() / (RAND_MAX + 1.0)));
+ nic_info->mac[3] = r[0] & 0x7f;
+ nic_info->mac[4] = r[1];
+ nic_info->mac[5] = r[2];
nic_info->ifname = NULL;
nic_info->bridge = strdup("xenbr0");
CHK_ERRNO( asprintf(&nic_info->script, "%s/vif-bridge",
@@ -347,21 +345,26 @@ static void init_nic_info(libxl_device_n
static void init_net2_info(libxl_device_net2 *net2_info, int devnum)
{
+ const uint8_t *r;
+ libxl_uuid uuid;
+
+ libxl_uuid_generate(&uuid);
+ r = libxl_uuid_bytearray(&uuid);
memset(net2_info, ''\0'', sizeof(*net2_info));
net2_info->devid = devnum;
net2_info->front_mac[0] = 0x00;
net2_info->front_mac[1] = 0x16;
net2_info->front_mac[2] = 0x3e;;
- net2_info->front_mac[3] = 1 + (int) (0x7f * (rand() / (RAND_MAX +
1.0)));
- net2_info->front_mac[4] = 1 + (int) (0xff * (rand() / (RAND_MAX +
1.0)));
- net2_info->front_mac[5] = 1 + (int) (0xff * (rand() / (RAND_MAX +
1.0)));
+ net2_info->front_mac[3] = 0x7f & r[0];
+ net2_info->front_mac[4] = r[1];
+ net2_info->front_mac[5] = r[2];
net2_info->back_mac[0] = 0x00;
net2_info->back_mac[1] = 0x16;
net2_info->back_mac[2] = 0x3e;
- net2_info->back_mac[3] = 1 + (int) (0x7f * (rand() / (RAND_MAX + 1.0)));
- net2_info->back_mac[4] = 1 + (int) (0xff * (rand() / (RAND_MAX + 1.0)));
- net2_info->back_mac[5] = 1 + (int) (0xff * (rand() / (RAND_MAX + 1.0)));
+ net2_info->back_mac[3] = 0x7f & r[3];
+ net2_info->back_mac[4] = r[4];
+ net2_info->back_mac[5] = r[5];
net2_info->back_trusted = 1;
net2_info->filter_mac = 1;
net2_info->max_bypasses = 5;
@@ -604,7 +607,10 @@ static void parse_config_data(const char
c_info->name = strdup(buf);
else
c_info->name = "test";
- random_uuid(&c_info->uuid);
+
+ if (!xlu_cfg_get_string (config, "uuid", &buf) ||
+ libxl_uuid_from_string(&c_info->uuid, buf) )
+ libxl_uuid_generate(&c_info->uuid);
if (!xlu_cfg_get_long(config, "oos", &l))
c_info->oos = l;
@@ -1206,7 +1212,7 @@ static int preserve_domain(libxl_ctx *ct
return 0;
}
- random_uuid(&new_uuid);
+ libxl_uuid_generate(&new_uuid);
LOG("Preserving domain %d %s with suffix%s", domid,
d_config->c_info.name, stime);
rc = libxl_domain_preserve(ctx, domid, &d_config->c_info, stime,
new_uuid);
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel