util: Add UUID API

A number of different places across the code base use CONFIG_UUID. Some
of them are soft dependency, some are not built if libuuid is not
available, some come with dummy fallback, some throws runtime error.

It is hard to maintain, and hard to reason for users.

Since UUID is a simple standard with only a small number of operations,
it is cleaner to have a central support in libqemuutil. This patch adds
qemu_uuid_* functions that all uuid users in the code base can
rely on. Except for qemu_uuid_generate which is new code, all other
functions are just copy from existing fallbacks from other files.

Note that qemu_uuid_parse is moved without updating the function
signature to use QemuUUID, to keep this patch simple.

Signed-off-by: Fam Zheng <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: Jeff Cody <[email protected]>
Message-Id: <1474432046[email protected]>

diff --git a/arch_init.c b/arch_init.c
index fa059731ed3f8c4669f07fdbc5d54949836ba29d..5cc58b2c3500fb2939ad1a81b113c284d52fb837 100644 (file)
--- a/arch_init.c
+++ b/arch_init.c
@@ -235,25 +235,6 @@ void audio_init(void)
     }
 }
 
-int qemu_uuid_parse(const char *str, uint8_t *uuid)
-{
-    int ret;
-
-    if (strlen(str) != 36) {
-        return -1;
-    }
-
-    ret = sscanf(str, UUID_FMT, &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 (ret != 16) {
-        return -1;
-    }
-    return 0;
-}
-
 void do_acpitable_option(const QemuOpts *opts)
 {
 #ifdef TARGET_I386

diff --git a/block/iscsi.c b/block/iscsi.c
index c4a093741924aff5bbe4ea0fd61ba2fa18c3e14a..40f88a2490163d0a154a52887f07c6df167e038c 100644 (file)
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -36,7 +36,7 @@
 #include "block/block_int.h"
 #include "block/scsi.h"
 #include "qemu/iov.h"
-#include "sysemu/sysemu.h"
+#include "qemu/uuid.h"
 #include "qmp-commands.h"
 #include "qapi/qmp/qstring.h"
 #include "crypto/secret.h"

diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index 74c71029294db50f38da08ce9a497a881ce13e0a..0705eb1dbde7b679728dfabf81225d64b7ce02b3 100644 (file)
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -20,6 +20,7 @@
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 #include "sysemu/sysemu.h"
+#include "qemu/uuid.h"
 #include "sysemu/cpus.h"
 #include "hw/smbios/smbios.h"
 #include "hw/loader.h"

diff --git a/include/qemu/uuid.h b/include/qemu/uuid.h
new file mode 100644 (file)
index 0000000..bc0601e
--- /dev/null
+++ b/include/qemu/uuid.h
@@ -0,0 +1,59 @@
+/*
+ *  QEMU UUID functions
+ *
+ *  Copyright 2016 Red Hat, Inc.
+ *
+ *  Authors:
+ *   Fam Zheng <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef QEMU_UUID_H
+#define QEMU_UUID_H
+
+#include "qemu-common.h"
+
+/* Version 4 UUID (pseudo random numbers), RFC4122 4.4. */
+
+typedef struct {
+    union {
+        unsigned char data[16];
+        struct {
+            /* Generated in BE endian, can be swapped with qemu_uuid_bswap. */
+            uint32_t time_low;
+            uint16_t time_mid;
+            uint16_t time_high_and_version;
+            uint8_t  clock_seq_and_reserved;
+            uint8_t  clock_seq_low;
+            uint8_t  node[6];
+        } fields;
+    };
+} QemuUUID;
+
+#define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-" \
+                 "%02hhx%02hhx-%02hhx%02hhx-" \
+                 "%02hhx%02hhx-" \
+                 "%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
+
+#define UUID_FMT_LEN 36
+
+#define UUID_NONE "00000000-0000-0000-0000-000000000000"
+
+void qemu_uuid_generate(QemuUUID *out);
+
+int qemu_uuid_is_null(const QemuUUID *uu);
+
+void qemu_uuid_unparse(const QemuUUID *uuid, char *out);
+
+char *qemu_uuid_unparse_strdup(const QemuUUID *uuid);
+
+int qemu_uuid_parse(const char *str, uint8_t *uuid);
+
+void qemu_uuid_bswap(QemuUUID *uuid);
+
+#endif

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index ee7c7608e073166854396aff6f74a23f2f26868e..6111950d512ec4c6b7c6fcf45da4211b85cb46fd 100644 (file)
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -18,10 +18,6 @@ extern const char *bios_name;
 extern const char *qemu_name;
 extern uint8_t qemu_uuid[];
 extern bool qemu_uuid_set;
-int qemu_uuid_parse(const char *str, uint8_t *uuid);
-
-#define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
-#define UUID_NONE "00000000-0000-0000-0000-000000000000"
 
 bool runstate_check(RunState state);
 void runstate_set(RunState new_state);

diff --git a/qmp.c b/qmp.c
index 6733463fa23288f3b4e0640ace49c54e5a0b43ff..524da629f85419faf34ac74120a7a9cdd24c21e8 100644 (file)
--- a/qmp.c
+++ b/qmp.c
@@ -18,6 +18,7 @@
 #include "qemu/cutils.h"
 #include "monitor/monitor.h"
 #include "sysemu/sysemu.h"
+#include "qemu/uuid.h"
 #include "qmp-commands.h"
 #include "sysemu/char.h"
 #include "ui/qemu-spice.h"

diff --git a/stubs/uuid.c b/stubs/uuid.c
index 92ad71783100c983d23091f25ec45887934c8f6c..a880de8d61d1c7fa3f63a2991bb9bca800f8ba68 100644 (file)
--- a/stubs/uuid.c
+++ b/stubs/uuid.c
@@ -1,6 +1,6 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
-#include "sysemu/sysemu.h"
+#include "qemu/uuid.h"
 #include "qmp-commands.h"
 
 UuidInfo *qmp_query_uuid(Error **errp)

diff --git a/util/Makefile.objs b/util/Makefile.objs
index ffca8f30026c9c0289d1c94e15ccacabfbd21b25..36c7dcc1fa1d9741811ac5b5e3d9f7b9a72624f6 100644 (file)
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -21,6 +21,7 @@ util-obj-y += iov.o qemu-config.o qemu-sockets.o uri.o notify.o
 util-obj-y += qemu-option.o qemu-progress.o
 util-obj-y += hexdump.o
 util-obj-y += crc32c.o
+util-obj-y += uuid.o
 util-obj-y += throttle.o
 util-obj-y += getauxval.o
 util-obj-y += readline.o

diff --git a/util/uuid.c b/util/uuid.c
new file mode 100644 (file)
index 0000000..6815904
--- /dev/null
+++ b/util/uuid.c
@@ -0,0 +1,91 @@
+/*
+ *  QEMU UUID functions
+ *
+ *  Copyright 2016 Red Hat, Inc.
+ *
+ *  Authors:
+ *   Fam Zheng <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/uuid.h"
+#include "qemu/bswap.h"
+
+void qemu_uuid_generate(QemuUUID *uuid)
+{
+    int i;
+    uint32_t tmp[4];
+
+    QEMU_BUILD_BUG_ON(sizeof(QemuUUID) != 16);
+
+    for (i = 0; i < 4; ++i) {
+        tmp[i] = g_random_int();
+    }
+    memcpy(uuid, tmp, sizeof(tmp));
+    /* Set the two most significant bits (bits 6 and 7) of the
+      clock_seq_hi_and_reserved to zero and one, respectively. */
+    uuid->data[8] = (uuid->data[8] & 0x3f) | 0x80;
+    /* Set the four most significant bits (bits 12 through 15) of the
+      time_hi_and_version field to the 4-bit version number.
+      */
+    uuid->data[6] = (uuid->data[6] & 0xf) | 0x40;
+}
+
+int qemu_uuid_is_null(const QemuUUID *uu)
+{
+    QemuUUID null_uuid = { 0 };
+    return memcmp(uu, &null_uuid, sizeof(QemuUUID)) == 0;
+}
+
+void qemu_uuid_unparse(const QemuUUID *uuid, char *out)
+{
+    const unsigned char *uu = &uuid->data[0];
+    snprintf(out, UUID_FMT_LEN + 1, UUID_FMT,
+             uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7],
+             uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]);
+}
+
+char *qemu_uuid_unparse_strdup(const QemuUUID *uuid)
+{
+    const unsigned char *uu = &uuid->data[0];
+    return g_strdup_printf(UUID_FMT,
+                           uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6],
+                           uu[7], uu[8], uu[9], uu[10], uu[11], uu[12],
+                           uu[13], uu[14], uu[15]);
+}
+
+int qemu_uuid_parse(const char *str, uint8_t *uuid)
+{
+    int ret;
+
+    if (strlen(str) != 36) {
+        return -1;
+    }
+
+    ret = sscanf(str, UUID_FMT, &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 (ret != 16) {
+        return -1;
+    }
+    return 0;
+}
+
+/* Swap from UUID format endian (BE) to the opposite or vice versa.
+ */
+void qemu_uuid_bswap(QemuUUID *uuid)
+{
+    assert(QEMU_PTR_IS_ALIGNED(uuid, sizeof(uint32_t)));
+    bswap32s(&uuid->fields.time_low);
+    bswap16s(&uuid->fields.time_mid);
+    bswap16s(&uuid->fields.time_high_and_version);
+}

diff --git a/vl.c b/vl.c
index fd321e2fd440cdfaf667454ce3367c75fe0d7c97..38395019f122f460481003a731797bdab217da2d 100644 (file)
--- a/vl.c
+++ b/vl.c
@@ -25,6 +25,7 @@
 #include "qemu-version.h"
 #include "qemu/cutils.h"
 #include "qemu/help_option.h"
+#include "qemu/uuid.h"
 
 #ifdef CONFIG_SECCOMP
 #include "sysemu/seccomp.h"