postgresql/contrib/uuid-ossp/uuid-ossp.c
2014-07-10 14:02:08 -04:00

533 lines
12 KiB
C

/*-------------------------------------------------------------------------
*
* UUID generation functions using the BSD, E2FS or OSSP UUID library
*
* Copyright (c) 2007-2014, PostgreSQL Global Development Group
*
* Portions Copyright (c) 2009 Andrew Gierth
*
* contrib/uuid-ossp/uuid-ossp.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "fmgr.h"
#include "utils/builtins.h"
#include "utils/uuid.h"
/*
* It's possible that there's more than one uuid.h header file present.
* We expect configure to set the HAVE_ symbol for only the one we want.
*
* BSD includes a uuid_hash() function that conflicts with the one in
* builtins.h; we #define it out of the way.
*/
#define uuid_hash bsd_uuid_hash
#ifdef HAVE_UUID_H
#include <uuid.h>
#endif
#ifdef HAVE_OSSP_UUID_H
#include <ossp/uuid.h>
#endif
#ifdef HAVE_UUID_UUID_H
#include <uuid/uuid.h>
#endif
#undef uuid_hash
/*
* Some BSD variants offer md5 and sha1 implementations but Linux does not,
* so we use a copy of the ones from pgcrypto. Not needed with OSSP, though.
*/
#ifndef HAVE_UUID_OSSP
#include "md5.h"
#include "sha1.h"
#endif
/* Check our UUID length against OSSP's; better both be 16 */
#if defined(HAVE_UUID_OSSP) && (UUID_LEN != UUID_LEN_BIN)
#error UUID length mismatch
#endif
/* Define some constants like OSSP's, to make the code more readable */
#ifndef HAVE_UUID_OSSP
#define UUID_MAKE_MC 0
#define UUID_MAKE_V1 1
#define UUID_MAKE_V2 2
#define UUID_MAKE_V3 3
#define UUID_MAKE_V4 4
#define UUID_MAKE_V5 5
#endif
/*
* A DCE 1.1 compatible source representation of UUIDs, derived from
* the BSD implementation. BSD already has this; OSSP doesn't need it.
*/
#ifdef HAVE_UUID_E2FS
typedef struct
{
uint32_t time_low;
uint16_t time_mid;
uint16_t time_hi_and_version;
uint8_t clock_seq_hi_and_reserved;
uint8_t clock_seq_low;
uint8_t node[6];
} dce_uuid_t;
#else
#define dce_uuid_t uuid_t
#endif
/* If not OSSP, we need some endianness-manipulation macros */
#ifndef HAVE_UUID_OSSP
#define UUID_TO_NETWORK(uu) \
do { \
uu.time_low = htonl(uu.time_low); \
uu.time_mid = htons(uu.time_mid); \
uu.time_hi_and_version = htons(uu.time_hi_and_version); \
} while (0)
#define UUID_TO_LOCAL(uu) \
do { \
uu.time_low = ntohl(uu.time_low); \
uu.time_mid = ntohs(uu.time_mid); \
uu.time_hi_and_version = ntohs(uu.time_hi_and_version); \
} while (0)
#define UUID_V3_OR_V5(uu, v) \
do { \
uu.time_hi_and_version &= 0x0FFF; \
uu.time_hi_and_version |= (v << 12); \
uu.clock_seq_hi_and_reserved &= 0x3F; \
uu.clock_seq_hi_and_reserved |= 0x80; \
} while(0)
#endif /* !HAVE_UUID_OSSP */
PG_MODULE_MAGIC;
PG_FUNCTION_INFO_V1(uuid_nil);
PG_FUNCTION_INFO_V1(uuid_ns_dns);
PG_FUNCTION_INFO_V1(uuid_ns_url);
PG_FUNCTION_INFO_V1(uuid_ns_oid);
PG_FUNCTION_INFO_V1(uuid_ns_x500);
PG_FUNCTION_INFO_V1(uuid_generate_v1);
PG_FUNCTION_INFO_V1(uuid_generate_v1mc);
PG_FUNCTION_INFO_V1(uuid_generate_v3);
PG_FUNCTION_INFO_V1(uuid_generate_v4);
PG_FUNCTION_INFO_V1(uuid_generate_v5);
#ifdef HAVE_UUID_OSSP
static void
pguuid_complain(uuid_rc_t rc)
{
char *err = uuid_error(rc);
if (err != NULL)
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("OSSP uuid library failure: %s", err)));
else
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("OSSP uuid library failure: error code %d", rc)));
}
/*
* We create a uuid_t object just once per session and re-use it for all
* operations in this module. OSSP UUID caches the system MAC address and
* other state in this object. Reusing the object has a number of benefits:
* saving the cycles needed to fetch the system MAC address over and over,
* reducing the amount of entropy we draw from /dev/urandom, and providing a
* positive guarantee that successive generated V1-style UUIDs don't collide.
* (On a machine fast enough to generate multiple UUIDs per microsecond,
* or whatever the system's wall-clock resolution is, we'd otherwise risk
* collisions whenever random initialization of the uuid_t's clock sequence
* value chanced to produce duplicates.)
*
* However: when we're doing V3 or V5 UUID creation, uuid_make needs two
* uuid_t objects, one holding the namespace UUID and one for the result.
* It's unspecified whether it's safe to use the same uuid_t for both cases,
* so let's cache a second uuid_t for use as the namespace holder object.
*/
static uuid_t *
get_cached_uuid_t(int which)
{
static uuid_t *cached_uuid[2] = {NULL, NULL};
if (cached_uuid[which] == NULL)
{
uuid_rc_t rc;
rc = uuid_create(&cached_uuid[which]);
if (rc != UUID_RC_OK)
{
cached_uuid[which] = NULL;
pguuid_complain(rc);
}
}
return cached_uuid[which];
}
static char *
uuid_to_string(const uuid_t *uuid)
{
char *buf = palloc(UUID_LEN_STR + 1);
void *ptr = buf;
size_t len = UUID_LEN_STR + 1;
uuid_rc_t rc;
rc = uuid_export(uuid, UUID_FMT_STR, &ptr, &len);
if (rc != UUID_RC_OK)
pguuid_complain(rc);
return buf;
}
static void
string_to_uuid(const char *str, uuid_t *uuid)
{
uuid_rc_t rc;
rc = uuid_import(uuid, UUID_FMT_STR, str, UUID_LEN_STR + 1);
if (rc != UUID_RC_OK)
pguuid_complain(rc);
}
static Datum
special_uuid_value(const char *name)
{
uuid_t *uuid = get_cached_uuid_t(0);
char *str;
uuid_rc_t rc;
rc = uuid_load(uuid, name);
if (rc != UUID_RC_OK)
pguuid_complain(rc);
str = uuid_to_string(uuid);
return DirectFunctionCall1(uuid_in, CStringGetDatum(str));
}
/* len is unused with OSSP, but we want to have the same number of args */
static Datum
uuid_generate_internal(int mode, const uuid_t *ns, const char *name, int len)
{
uuid_t *uuid = get_cached_uuid_t(0);
char *str;
uuid_rc_t rc;
rc = uuid_make(uuid, mode, ns, name);
if (rc != UUID_RC_OK)
pguuid_complain(rc);
str = uuid_to_string(uuid);
return DirectFunctionCall1(uuid_in, CStringGetDatum(str));
}
static Datum
uuid_generate_v35_internal(int mode, pg_uuid_t *ns, text *name)
{
uuid_t *ns_uuid = get_cached_uuid_t(1);
string_to_uuid(DatumGetCString(DirectFunctionCall1(uuid_out,
UUIDPGetDatum(ns))),
ns_uuid);
return uuid_generate_internal(mode,
ns_uuid,
text_to_cstring(name),
0);
}
#else /* !HAVE_UUID_OSSP */
static Datum
uuid_generate_internal(int v, unsigned char *ns, char *ptr, int len)
{
char strbuf[40];
switch (v)
{
case 0: /* constant-value uuids */
strlcpy(strbuf, ptr, 37);
break;
case 1: /* time/node-based uuids */
{
#ifdef HAVE_UUID_E2FS
uuid_t uu;
uuid_generate_time(uu);
uuid_unparse(uu, strbuf);
/*
* PTR, if set, replaces the trailing characters of the uuid;
* this is to support v1mc, where a random multicast MAC is
* used instead of the physical one
*/
if (ptr && len <= 36)
strcpy(strbuf + (36 - len), ptr);
#else /* BSD */
uuid_t uu;
uint32_t status = uuid_s_ok;
char *str = NULL;
uuid_create(&uu, &status);
if (status == uuid_s_ok)
{
uuid_to_string(&uu, &str, &status);
if (status == uuid_s_ok)
{
strlcpy(strbuf, str, 37);
/*
* PTR, if set, replaces the trailing characters of
* the uuid; this is to support v1mc, where a random
* multicast MAC is used instead of the physical one
*/
if (ptr && len <= 36)
strcpy(strbuf + (36 - len), ptr);
}
if (str)
free(str);
}
if (status != uuid_s_ok)
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("uuid library failure: %d",
(int) status)));
#endif
break;
}
case 3: /* namespace-based MD5 uuids */
case 5: /* namespace-based SHA1 uuids */
{
dce_uuid_t uu;
#ifdef HAVE_UUID_BSD
uint32_t status = uuid_s_ok;
char *str = NULL;
#endif
if (v == 3)
{
MD5_CTX ctx;
MD5Init(&ctx);
MD5Update(&ctx, ns, sizeof(uu));
MD5Update(&ctx, (unsigned char *) ptr, len);
/* we assume sizeof MD5 result is 16, same as UUID size */
MD5Final((unsigned char *) &uu, &ctx);
}
else
{
SHA1_CTX ctx;
unsigned char sha1result[SHA1_RESULTLEN];
SHA1Init(&ctx);
SHA1Update(&ctx, ns, sizeof(uu));
SHA1Update(&ctx, (unsigned char *) ptr, len);
SHA1Final(sha1result, &ctx);
memcpy(&uu, sha1result, sizeof(uu));
}
/* the calculated hash is using local order */
UUID_TO_NETWORK(uu);
UUID_V3_OR_V5(uu, v);
#ifdef HAVE_UUID_E2FS
/* uuid_unparse expects local order */
UUID_TO_LOCAL(uu);
uuid_unparse((unsigned char *) &uu, strbuf);
#else /* BSD */
uuid_to_string(&uu, &str, &status);
if (status == uuid_s_ok)
strlcpy(strbuf, str, 37);
if (str)
free(str);
if (status != uuid_s_ok)
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("uuid library failure: %d",
(int) status)));
#endif
break;
}
case 4: /* random uuid */
default:
{
#ifdef HAVE_UUID_E2FS
uuid_t uu;
uuid_generate_random(uu);
uuid_unparse(uu, strbuf);
#else /* BSD */
snprintf(strbuf, sizeof(strbuf),
"%08lx-%04x-%04x-%04x-%04x%08lx",
(unsigned long) arc4random(),
(unsigned) (arc4random() & 0xffff),
(unsigned) ((arc4random() & 0xfff) | 0x4000),
(unsigned) ((arc4random() & 0x3fff) | 0x8000),
(unsigned) (arc4random() & 0xffff),
(unsigned long) arc4random());
#endif
break;
}
}
return DirectFunctionCall1(uuid_in, CStringGetDatum(strbuf));
}
#endif /* HAVE_UUID_OSSP */
Datum
uuid_nil(PG_FUNCTION_ARGS)
{
#ifdef HAVE_UUID_OSSP
return special_uuid_value("nil");
#else
return uuid_generate_internal(0, NULL,
"00000000-0000-0000-0000-000000000000", 36);
#endif
}
Datum
uuid_ns_dns(PG_FUNCTION_ARGS)
{
#ifdef HAVE_UUID_OSSP
return special_uuid_value("ns:DNS");
#else
return uuid_generate_internal(0, NULL,
"6ba7b810-9dad-11d1-80b4-00c04fd430c8", 36);
#endif
}
Datum
uuid_ns_url(PG_FUNCTION_ARGS)
{
#ifdef HAVE_UUID_OSSP
return special_uuid_value("ns:URL");
#else
return uuid_generate_internal(0, NULL,
"6ba7b811-9dad-11d1-80b4-00c04fd430c8", 36);
#endif
}
Datum
uuid_ns_oid(PG_FUNCTION_ARGS)
{
#ifdef HAVE_UUID_OSSP
return special_uuid_value("ns:OID");
#else
return uuid_generate_internal(0, NULL,
"6ba7b812-9dad-11d1-80b4-00c04fd430c8", 36);
#endif
}
Datum
uuid_ns_x500(PG_FUNCTION_ARGS)
{
#ifdef HAVE_UUID_OSSP
return special_uuid_value("ns:X500");
#else
return uuid_generate_internal(0, NULL,
"6ba7b814-9dad-11d1-80b4-00c04fd430c8", 36);
#endif
}
Datum
uuid_generate_v1(PG_FUNCTION_ARGS)
{
return uuid_generate_internal(UUID_MAKE_V1, NULL, NULL, 0);
}
Datum
uuid_generate_v1mc(PG_FUNCTION_ARGS)
{
#ifdef HAVE_UUID_OSSP
char *buf = NULL;
#elif defined(HAVE_UUID_E2FS)
char strbuf[40];
char *buf;
uuid_t uu;
uuid_generate_random(uu);
/* set IEEE802 multicast and local-admin bits */
((dce_uuid_t *) &uu)->node[0] |= 0x03;
uuid_unparse(uu, strbuf);
buf = strbuf + 24;
#else /* BSD */
char buf[16];
/* set IEEE802 multicast and local-admin bits */
snprintf(buf, sizeof(buf), "-%04x%08lx",
(unsigned) ((arc4random() & 0xffff) | 0x0300),
(unsigned long) arc4random());
#endif
return uuid_generate_internal(UUID_MAKE_V1 | UUID_MAKE_MC, NULL,
buf, 13);
}
Datum
uuid_generate_v3(PG_FUNCTION_ARGS)
{
pg_uuid_t *ns = PG_GETARG_UUID_P(0);
text *name = PG_GETARG_TEXT_P(1);
#ifdef HAVE_UUID_OSSP
return uuid_generate_v35_internal(UUID_MAKE_V3, ns, name);
#else
return uuid_generate_internal(UUID_MAKE_V3, (unsigned char *) ns,
VARDATA(name), VARSIZE(name) - VARHDRSZ);
#endif
}
Datum
uuid_generate_v4(PG_FUNCTION_ARGS)
{
return uuid_generate_internal(UUID_MAKE_V4, NULL, NULL, 0);
}
Datum
uuid_generate_v5(PG_FUNCTION_ARGS)
{
pg_uuid_t *ns = PG_GETARG_UUID_P(0);
text *name = PG_GETARG_TEXT_P(1);
#ifdef HAVE_UUID_OSSP
return uuid_generate_v35_internal(UUID_MAKE_V5, ns, name);
#else
return uuid_generate_internal(UUID_MAKE_V5, (unsigned char *) ns,
VARDATA(name), VARSIZE(name) - VARHDRSZ);
#endif
}