Module Name: src
Committed By: riastradh
Date: Sat Oct 4 11:15:44 UTC 2014
Modified Files:
src/sys/kern: init_main.c kern_uuid.c
src/sys/sys: uuid.h
Log Message:
Make uuidgen(2) generate v4 (random) uuids.
Rip out all the needless MAC address and date/time leakage. No more
uuid_init necessary, nor contention over a global uuid state.
While here, simplify uuid_snprintf and fix a strict aliasing
violation.
To generate a diff of this commit:
cvs rdiff -u -r1.459 -r1.460 src/sys/kern/init_main.c
cvs rdiff -u -r1.18 -r1.19 src/sys/kern/kern_uuid.c
cvs rdiff -u -r1.5 -r1.6 src/sys/sys/uuid.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/init_main.c
diff -u src/sys/kern/init_main.c:1.459 src/sys/kern/init_main.c:1.460
--- src/sys/kern/init_main.c:1.459 Thu Aug 14 16:27:55 2014
+++ src/sys/kern/init_main.c Sat Oct 4 11:15:44 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: init_main.c,v 1.459 2014/08/14 16:27:55 riastradh Exp $ */
+/* $NetBSD: init_main.c,v 1.460 2014/10/04 11:15:44 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -97,7 +97,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: init_main.c,v 1.459 2014/08/14 16:27:55 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: init_main.c,v 1.460 2014/10/04 11:15:44 riastradh Exp $");
#include "opt_ddb.h"
#include "opt_ipsec.h"
@@ -605,9 +605,6 @@ main(void)
ptrace_init();
#endif /* PTRACE */
- /* Initialize the UUID system calls. */
- uuid_init();
-
machdep_init();
procinit_sysctl();
Index: src/sys/kern/kern_uuid.c
diff -u src/sys/kern/kern_uuid.c:1.18 src/sys/kern/kern_uuid.c:1.19
--- src/sys/kern/kern_uuid.c:1.18 Sat Nov 19 22:51:25 2011
+++ src/sys/kern/kern_uuid.c Sat Oct 4 11:15:44 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_uuid.c,v 1.18 2011/11/19 22:51:25 tls Exp $ */
+/* $NetBSD: kern_uuid.c,v 1.19 2014/10/04 11:15:44 riastradh Exp $ */
/*
* Copyright (c) 2002 Marcel Moolenaar
@@ -29,190 +29,46 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.18 2011/11/19 22:51:25 tls Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.19 2014/10/04 11:15:44 riastradh Exp $");
#include <sys/param.h>
+#include <sys/cprng.h>
#include <sys/endian.h>
-#include <sys/kernel.h>
-#include <sys/mutex.h>
-#include <sys/socket.h>
+#include <sys/syscallargs.h>
#include <sys/systm.h>
#include <sys/uuid.h>
-/* NetBSD */
-#include <sys/proc.h>
-#include <sys/mount.h>
-#include <sys/syscallargs.h>
-#include <sys/uio.h>
-#include <sys/cprng.h>
-
-#include <net/if.h>
-#include <net/if_dl.h>
-#include <net/if_types.h>
-
/*
* See also:
* http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
* http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
- *
- * Note that the generator state is itself an UUID, but the time and clock
- * sequence fields are written in the native byte order.
*/
CTASSERT(sizeof(struct uuid) == 16);
-/* We use an alternative, more convenient representation in the generator. */
-struct uuid_private {
- union {
- uint64_t ll; /* internal. */
- struct {
- uint32_t low;
- uint16_t mid;
- uint16_t hi;
- } x;
- } time;
- uint16_t seq; /* Big-endian. */
- uint16_t node[UUID_NODE_LEN>>1];
-};
-
-CTASSERT(sizeof(struct uuid_private) == 16);
-
-static struct uuid_private uuid_last;
-
-/* "UUID generator mutex lock" */
-static kmutex_t uuid_mutex;
-
-void
-uuid_init(void)
-{
-
- mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE);
-}
-
-/*
- * Return the first MAC address we encounter or, if none was found,
- * construct a sufficiently random multicast address. We don't try
- * to return the same MAC address as previously returned. We always
- * generate a new multicast address if no MAC address exists in the
- * system.
- * It would be nice to know if 'ifnet' or any of its sub-structures
- * has been changed in any way. If not, we could simply skip the
- * scan and safely return the MAC address we returned before.
- */
-static void
-uuid_node(uint16_t *node)
-{
- struct ifnet *ifp;
- struct ifaddr *ifa;
- struct sockaddr_dl *sdl;
- int i, s;
-
- s = splnet();
- KERNEL_LOCK(1, NULL);
- IFNET_FOREACH(ifp) {
- /* Walk the address list */
- IFADDR_FOREACH(ifa, ifp) {
- sdl = (struct sockaddr_dl*)ifa->ifa_addr;
- if (sdl != NULL && sdl->sdl_family == AF_LINK &&
- sdl->sdl_type == IFT_ETHER) {
- /* Got a MAC address. */
- memcpy(node, CLLADDR(sdl), UUID_NODE_LEN);
- KERNEL_UNLOCK_ONE(NULL);
- splx(s);
- return;
- }
- }
- }
- KERNEL_UNLOCK_ONE(NULL);
- splx(s);
-
- for (i = 0; i < (UUID_NODE_LEN>>1); i++)
- node[i] = (uint16_t)cprng_fast32();
- *((uint8_t*)node) |= 0x01;
-}
-
-/*
- * Get the current time as a 60 bit count of 100-nanosecond intervals
- * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
- * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
- * Gregorian reform to the Christian calendar.
- */
-static uint64_t
-uuid_time(void)
-{
- struct timespec tsp;
- uint64_t xtime = 0x01B21DD213814000LL;
-
- nanotime(&tsp);
- xtime += (uint64_t)tsp.tv_sec * 10000000LL;
- xtime += (uint64_t)(tsp.tv_nsec / 100);
- return (xtime & ((1LL << 60) - 1LL));
-}
-
-/*
- * Internal routine to actually generate the UUID.
- */
static void
-uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count)
+uuid_generate(struct uuid *uuid)
{
- uint64_t xtime;
- mutex_enter(&uuid_mutex);
+ /* Randomly generate the content. */
+ cprng_fast(uuid, sizeof(*uuid));
- uuid_node(uuid->node);
- xtime = uuid_time();
- *timep = xtime;
-
- if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] ||
- uuid_last.node[1] != uuid->node[1] ||
- uuid_last.node[2] != uuid->node[2])
- uuid->seq = (uint16_t)cprng_fast32() & 0x3fff;
- else if (uuid_last.time.ll >= xtime)
- uuid->seq = (uuid_last.seq + 1) & 0x3fff;
- else
- uuid->seq = uuid_last.seq;
+ /* Set the version number to 4. */
+ uuid->time_hi_and_version &= ~(uint32_t)0xf000;
+ uuid->time_hi_and_version |= 0x4000;
- uuid_last = *uuid;
- uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL);
-
- mutex_exit(&uuid_mutex);
-}
-
-static int
-kern_uuidgen(struct uuid *store, int count, bool to_user)
-{
- struct uuid_private uuid;
- uint64_t xtime;
- int error = 0, i;
-
- KASSERT(count >= 1);
-
- /* Generate the base UUID. */
- uuid_generate(&uuid, &xtime, count);
-
- /* Set sequence and variant and deal with byte order. */
- uuid.seq = htobe16(uuid.seq | 0x8000);
-
- for (i = 0; i < count; xtime++, i++) {
- /* Set time and version (=1) and deal with byte order. */
- uuid.time.x.low = (uint32_t)xtime;
- uuid.time.x.mid = (uint16_t)(xtime >> 32);
- uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12);
- if (to_user) {
- error = copyout(&uuid, store + i, sizeof(uuid));
- if (error != 0)
- break;
- } else {
- memcpy(store + i, &uuid, sizeof(uuid));
- }
- }
-
- return error;
+ /* Fix the reserved bits. */
+ uuid->clock_seq_hi_and_reserved &= ~(uint8_t)0x40;
+ uuid->clock_seq_hi_and_reserved |= 0x80;
}
int
sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval)
{
+ struct uuid *store, tmp;
+ unsigned count;
+ int error;
+
/*
* Limit the number of UUIDs that can be created at the same time
* to some arbitrary number. This isn't really necessary, but I
@@ -222,26 +78,37 @@ sys_uuidgen(struct lwp *l, const struct
if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048)
return (EINVAL);
- return kern_uuidgen(SCARG(uap, store), SCARG(uap,count), true);
+ for (store = SCARG(uap,store), count = SCARG(uap,count);
+ count > 0;
+ store++, count--) {
+ uuid_generate(&tmp);
+ error = copyout(store, &tmp, sizeof tmp);
+ if (error)
+ return error;
+ }
+
+ return 0;
}
int
uuidgen(struct uuid *store, int count)
{
- return kern_uuidgen(store,count, false);
+
+ while (--count > 0)
+ uuid_generate(store++);
+ return 0;
}
int
uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid)
{
- const struct uuid_private *id;
- int cnt;
- id = (const struct uuid_private *)uuid;
- cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
- id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
- be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
- return (cnt);
+ return snprintf(buf, sz,
+ "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+ uuid->time_low, uuid->time_mid, uuid->time_hi_and_version,
+ uuid->clock_seq_hi_and_reserved, uuid->clock_seq_low,
+ uuid->node[0], uuid->node[1], uuid->node[2], uuid->node[3],
+ uuid->node[4], uuid->node[5]);
}
int
Index: src/sys/sys/uuid.h
diff -u src/sys/sys/uuid.h:1.5 src/sys/sys/uuid.h:1.6
--- src/sys/sys/uuid.h:1.5 Tue Nov 18 14:01:03 2008
+++ src/sys/sys/uuid.h Sat Oct 4 11:15:44 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: uuid.h,v 1.5 2008/11/18 14:01:03 joerg Exp $ */
+/* $NetBSD: uuid.h,v 1.6 2014/10/04 11:15:44 riastradh Exp $ */
/*
* Copyright (c) 2002 Marcel Moolenaar
@@ -66,7 +66,6 @@ void uuid_dec_be(const void *, struct uu
void uuid_dec_le(const void *, struct uuid *);
void uuid_enc_be(void *, const struct uuid *);
void uuid_enc_le(void *, const struct uuid *);
-void uuid_init(void);
int uuidgen(struct uuid *, int);
#else /* _KERNEL */
