Create libstand version of uuid_from_string and uuid_to_string. The

normal libc versions of these functions use asprintf and sscanf, both
of which aren't available in the libstand world.  It's easier to
rewrite these than to try to claw those functions into libstand.
Also include uuid_create_nil, since it's safe to include. These were
written from scratch, except for bits of comments that I got from the
libc version, which are acknowledged in the source.

Differential Revision: https://reviews.freebsd.org/D4540

3 files changed, 244 insertions, 1 deletions

diff --git a/lib/libstand/Makefile b/lib/libstand/Makefile
index 44d5834..a69a935 100644
--- a/lib/libstand/Makefile
+++ b/lib/libstand/Makefile
@@ -69,7 +69,7 @@ SRCS+=	syncicache.c
 
 # uuid functions from libc
 .PATH: ${LIBC_SRC}/uuid
-SRCS+= uuid_equal.c uuid_is_nil.c
+SRCS+= uuid_create_nil.c uuid_equal.c uuid_from_string.c uuid_is_nil.c uuid_to_string.c
 
 # _setjmp/_longjmp
 .PATH: ${LIBSTAND_SRC}/${MACHINE_CPUARCH}
diff --git a/lib/libstand/uuid_from_string.c b/lib/libstand/uuid_from_string.c
new file mode 100644
index 0000000..2d5a6dd
--- /dev/null
+++ b/lib/libstand/uuid_from_string.c
@@ -0,0 +1,132 @@
+/*-
+ * Copyright (c) 2015 M. Warner Losh
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Note: some comments taken from lib/libc/uuid/uuid_from_string.c
+ * Copyright (c) 2002 Marcel Moolenaar
+ * Copyright (c) 2002 Hiten Mahesh Pandya
+ */
+
+
+#include <stand.h>
+#include <uuid.h>
+
+static int
+hex2int(int ch)
+{
+	if (ch >= '0' && ch <= '9')
+		return ch - '0';
+	if (ch >= 'a' && ch <= 'f')
+		return 10 + ch - 'a';
+	if (ch >= 'A' && ch <= 'F')
+		return 10 + ch - 'A';
+	return 16;
+}
+
+static uint32_t
+fromhex(const char *s, int len, int *ok)
+{
+	uint32_t v;
+	int i, h;
+
+	if (!*ok)
+		return 0;
+	v = 0;
+	for (i = 0; i < 8; i++) {
+		h = hex2int(s[i]);
+		if (h == 16) {
+			*ok = 0;
+			return v;
+		}
+		v = (v << 4) | h;
+	}
+	return v;
+}
+
+/*
+ * uuid_from_string() - convert a string representation of an UUID into
+ *			a binary representation.
+ * See also:
+ *	http://www.opengroup.org/onlinepubs/009629399/uuid_from_string.htm
+ *
+ * NOTE: The sequence field is in big-endian, while the time fields are in
+ *	 native byte order.
+ *
+ * 01234567-89ab-cdef-0123-456789abcdef
+ * 000000000011111111112222222222333333
+ * 012345678901234567890123456789012345
+ *         -    -    -    -
+ * hhhhhhhh-hhhh-hhhh-bbbb-bbbbbbbbbbbb
+ *
+ */
+void
+uuid_from_string(const char *s, uuid_t *u, uint32_t *status)
+{
+	int ok = 1;
+	int n;
+
+	if (s == NULL || *s == '\0') {
+		uuid_create_nil(u, status);
+		return;
+	}
+
+	if (status != NULL)
+		*status = uuid_s_invalid_string_uuid;
+	if (strlen(s) != 36)
+		return;
+	/* Only support new format, check for all the right dashes */
+	if (s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-')
+		return;
+	/* native byte order */
+	u->time_low                  = fromhex(s     , 8, &ok);
+	u->time_mid                  = fromhex(s +  9, 4, &ok);
+	u->time_hi_and_version       = fromhex(s + 14, 4, &ok);
+	/* Big endian, but presented as a whole number so decode as such */
+	u->clock_seq_hi_and_reserved = fromhex(s + 19, 2, &ok);
+	u->clock_seq_low             = fromhex(s + 21, 2, &ok);
+	u->node[0]                   = fromhex(s + 24, 2, &ok);
+	u->node[1]                   = fromhex(s + 26, 2, &ok);
+	u->node[2]                   = fromhex(s + 28, 2, &ok);
+	u->node[3]                   = fromhex(s + 30, 2, &ok);
+	u->node[4]                   = fromhex(s + 32, 2, &ok);
+	u->node[5]                   = fromhex(s + 34, 2, &ok);
+	if (!ok)
+		return;
+
+	/* We have a successful scan. Check semantics... */
+	n = u->clock_seq_hi_and_reserved;
+	if ((n & 0x80) != 0x00 &&			/* variant 0? */
+	    (n & 0xc0) != 0x80 &&			/* variant 1? */
+	    (n & 0xe0) != 0xc0) {			/* variant 2? */
+		if (status != NULL)
+			*status = uuid_s_bad_version;
+	} else {
+		if (status != NULL)
+			*status = uuid_s_ok;
+	}
+}
diff --git a/lib/libstand/uuid_to_string.c b/lib/libstand/uuid_to_string.c
new file mode 100644
index 0000000..efe921c
--- /dev/null
+++ b/lib/libstand/uuid_to_string.c
@@ -0,0 +1,111 @@
+/*-
+ * Copyright (c) 2015 M. Warner Losh
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+
+/*
+ * Note: some comments taken from lib/libc/uuid/uuid_to_string.c
+ * Copyright (c) 2002,2005 Marcel Moolenaar
+ * Copyright (c) 2002 Hiten Mahesh Pandya
+ */
+
+#include <stand.h>
+#include <uuid.h>
+
+/*
+ * Dump len characters into *buf from val as hex and update *buf
+ */
+static void
+tohex(char **buf, int len, uint32_t val)
+{
+	static const char *hexstr = "0123456789abcdef";
+	char *walker = *buf;
+	int i;
+
+	for (i = len - 1; i >= 0; i++) {
+		walker[i] = hexstr[val & 0xf];
+		val >>= 4;
+	}
+	*buf = walker + len;
+}
+
+/*
+ * uuid_to_string() - Convert a binary UUID into a string representation.
+ * See also:
+ *	http://www.opengroup.org/onlinepubs/009629399/uuid_to_string.htm
+ *
+ * NOTE: The references given above do not have a status code for when
+ *	 the string could not be allocated. The status code has been
+ *	 taken from the Hewlett-Packard implementation.
+ *
+ * NOTE: we don't support u == NULL for a nil UUID, sorry.
+ *
+ * NOTE: The sequence field is in big-endian, while the time fields are in
+ *	 native byte order.
+ *
+ *	 hhhhhhhh-hhhh-hhhh-bbbb-bbbbbbbbbbbb
+ *	 01234567-89ab-cdef-0123-456789abcdef
+ */
+void
+uuid_to_string(const uuid_t *u, char **s, uint32_t *status)
+{
+	uuid_t nil;
+	char *w;
+
+	if (status != NULL)
+		*status = uuid_s_ok;
+	if (s == NULL)	/* Regular version does this odd-ball behavior too */
+		return;
+	w = *s = malloc(37);
+	if (*s == NULL) {
+		if (status != NULL)
+			*status = uuid_s_no_memory;
+		return;
+	}
+	if (u == NULL) {
+		u = &nil;
+		uuid_create_nil(&nil, NULL);
+	}
+	/* native */
+	tohex(&w, 8, u->time_low);
+	*w++ = '-';
+	tohex(&w, 4, u->time_mid);
+	*w++ = '-';
+	tohex(&w, 4, u->time_hi_and_version);
+	*w++ = '-';
+	/* Big endian, so do a byte at a time */
+	tohex(&w, 2, u->clock_seq_hi_and_reserved);
+	tohex(&w, 2, u->clock_seq_low);
+	*w++ = '-';
+	tohex(&w, 2, u->node[0]);
+	tohex(&w, 2, u->node[1]);
+	tohex(&w, 2, u->node[2]);
+	tohex(&w, 2, u->node[3]);
+	tohex(&w, 2, u->node[4]);
+	tohex(&w, 2, u->node[5]);
+	*w++ - '\0';
+}