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[Xen-devel] [PATCH,v5]: xl: randomly generate UUID's

To: Xen Devel <xen-devel@xxxxxxxxxxxxxxxxxxx>

From: Gianni Tedesco <gianni.tedesco@xxxxxxxxxx>

Date: Wed, 1 Sep 2010 16:59:06 +0100

Cc: Christoph Egger <Christoph.Egger@xxxxxxx>, Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>, Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>

Delivery-date: Wed, 01 Sep 2010 09:09:01 -0700

List-id: Xen developer discussion <xen-devel.lists.xensource.com>

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@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel

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