[uuid] Add uuid_aton() to parse a UUID from a string

Add uuid_aton() to parse a UUID value from a string (analogous to
inet_aton(), inet6_aton(), sock_aton(), etc), treating it as a
32-digit hex string with optional hyphen separators.  The placement of
the separators is not checked: each byte within the hex string may be
separated by a hyphen, or not separated at all.

Add dedicated self-tests for UUID parsing and formatting (already
partially covered by the ":uuid" and ":guid" settings self-tests).

Signed-off-by: Michael Brown <mcb30@ipxe.org>

7 files changed, 203 insertions, 2 deletions

diff --git a/src/core/base16.c b/src/core/base16.c
index f9e0f336..47e35f41 100644
--- a/src/core/base16.c
+++ b/src/core/base16.c
@@ -78,12 +78,23 @@ int hex_decode ( char separator, const char *encoded, void *data, size_t len ) {
 	unsigned int count = 0;
 	unsigned int sixteens;
 	unsigned int units;
+	int optional;
 
+	/* Strip out optionality flag from separator character */
+	optional = ( separator & HEX_DECODE_OPTIONAL );
+	separator &= ~HEX_DECODE_OPTIONAL;
+
+	/* Decode string */
 	while ( *encoded ) {
 
 		/* Check separator, if applicable */
-		if ( count && separator && ( ( *(encoded++) != separator ) ) )
-			return -EINVAL;
+		if ( count && separator ) {
+			if ( *encoded == separator ) {
+				encoded++;
+			} else if ( ! optional ) {
+				return -EINVAL;
+			}
+		}
 
 		/* Extract digits.  Note that either digit may be NUL,
 		 * which would be interpreted as an invalid value by
diff --git a/src/core/uuid.c b/src/core/uuid.c
index c43d4216..b6600af7 100644
--- a/src/core/uuid.c
+++ b/src/core/uuid.c
@@ -25,7 +25,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stdint.h>
 #include <stdio.h>
+#include <errno.h>
 #include <byteswap.h>
+#include <ipxe/base16.h>
 #include <ipxe/uuid.h>
 
 /** @file
@@ -53,3 +55,29 @@ const char * uuid_ntoa ( const union uuid *uuid ) {
 		  uuid->canonical.e[4], uuid->canonical.e[5] );
 	return buf;
 }
+
+/**
+ * Parse UUID
+ *
+ * @v string		UUID string
+ * @v uuid		UUID to fill in
+ * @ret rc		Return status code
+ */
+int uuid_aton ( const char *string, union uuid *uuid ) {
+	int len;
+	int rc;
+
+	/* Decode as hex string with optional '-' separator */
+	len = hex_decode ( ( '-' | HEX_DECODE_OPTIONAL ), string, uuid->raw,
+			   sizeof ( *uuid ) );
+	if ( len < 0 ) {
+		rc = len;
+		return rc;
+	}
+
+	/* Check length */
+	if ( len != sizeof ( *uuid ) )
+		return -EINVAL;
+
+	return 0;
+}
diff --git a/src/include/ipxe/base16.h b/src/include/ipxe/base16.h
index 8c44da17..c9e430e7 100644
--- a/src/include/ipxe/base16.h
+++ b/src/include/ipxe/base16.h
@@ -12,6 +12,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <stdint.h>
 #include <string.h>
 
+/** Treat separator as optional while decoding */
+#define HEX_DECODE_OPTIONAL 0x80
+
 /**
  * Calculate length of base16-encoded data
  *
diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index 662f8496..7cff594d 100644
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -79,6 +79,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_cachedhcp	       ( ERRFILE_CORE | 0x00270000 )
 #define ERRFILE_acpimac		       ( ERRFILE_CORE | 0x00280000 )
 #define ERRFILE_efi_strings	       ( ERRFILE_CORE | 0x00290000 )
+#define ERRFILE_uuid		       ( ERRFILE_CORE | 0x002a0000 )
 
 #define ERRFILE_eisa		     ( ERRFILE_DRIVER | 0x00000000 )
 #define ERRFILE_isa		     ( ERRFILE_DRIVER | 0x00010000 )
diff --git a/src/include/ipxe/uuid.h b/src/include/ipxe/uuid.h
index 24c46aca..4874b738 100644
--- a/src/include/ipxe/uuid.h
+++ b/src/include/ipxe/uuid.h
@@ -48,5 +48,6 @@ static inline void uuid_mangle ( union uuid *uuid ) {
 }
 
 extern const char * uuid_ntoa ( const union uuid *uuid );
+extern int uuid_aton ( const char *string, union uuid *uuid );
 
 #endif /* _IPXE_UUID_H */
diff --git a/src/tests/tests.c b/src/tests/tests.c
index 90cec948..cb296049 100644
--- a/src/tests/tests.c
+++ b/src/tests/tests.c
@@ -84,3 +84,4 @@ REQUIRE_OBJECT ( nap_test );
 REQUIRE_OBJECT ( x25519_test );
 REQUIRE_OBJECT ( des_test );
 REQUIRE_OBJECT ( mschapv2_test );
+REQUIRE_OBJECT ( uuid_test );
diff --git a/src/tests/uuid_test.c b/src/tests/uuid_test.c
new file mode 100644
index 00000000..42dc5264
--- /dev/null
+++ b/src/tests/uuid_test.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2024 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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.
+ *
+ * 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * UUID tests
+ *
+ */
+
+/* Forcibly enable assertions */
+#undef NDEBUG
+
+#include <string.h>
+#include <byteswap.h>
+#include <ipxe/uuid.h>
+#include <ipxe/test.h>
+
+/** Define an inline UUID value */
+#define UUID( A, B, C, D, E0, E1, E2, E3, E4, E5 ) {		\
+		.a = htonl ( A ),				\
+		.b = htons ( B ),				\
+		.c = htons ( C ),				\
+		.d = htons ( D ),				\
+		.e = { E0, E1, E2, E3, E4, E5 },		\
+	}
+
+/**
+ * Report a uuid_ntoa() test result
+ *
+ * @v uuid		UUID
+ * @v text		Expected textual representation
+ * @v file		Test code file
+ * @v line		Test code line
+ */
+static void uuid_ntoa_okx ( const union uuid *uuid, const char *text,
+			    const char *file, unsigned int line ) {
+	const char *actual;
+
+	/* Format address */
+	actual = uuid_ntoa ( uuid );
+	DBG ( "uuid_ntoa ( %08x-%04x-%04x-%04x-%02x%02x%02x%02x%02x%02x ) = "
+	      "\"%s\"\n", ntohl ( uuid->canonical.a ),
+	      ntohs ( uuid->canonical.b ), ntohs ( uuid->canonical.c ),
+	      ntohs ( uuid->canonical.d ), uuid->canonical.e[0],
+	      uuid->canonical.e[1], uuid->canonical.e[2], uuid->canonical.e[3],
+	      uuid->canonical.e[4], uuid->canonical.e[5], actual );
+	okx ( strcmp ( actual, text ) == 0, file, line );
+}
+#define uuid_ntoa_ok( value, text ) do {				\
+	static const union uuid uuid = {				\
+		.canonical = value,					\
+	};								\
+	uuid_ntoa_okx ( &uuid, text, __FILE__, __LINE__ );		\
+	} while ( 0 )
+
+/**
+ * Report a uuid_aton() test result
+ *
+ * @v text		Textual representation
+ * @v uuid		Expected UUID
+ * @v file		Test code file
+ * @v line		Test code line
+ */
+static void uuid_aton_okx ( const char *text, const union uuid *uuid,
+			    const char *file, unsigned int line ) {
+	union uuid actual;
+
+	/* Parse address */
+	okx ( uuid_aton ( text, &actual ) == 0, file, line );
+	DBG ( "uuid_aton ( \"%s\" ) = %s\n", text, uuid_ntoa ( &actual ) );
+	okx ( memcmp ( &actual, uuid, sizeof ( actual ) ) == 0, file, line );
+};
+#define uuid_aton_ok( text, value ) do {				\
+	static const union uuid uuid = {				\
+		.canonical = value,					\
+	};								\
+	uuid_aton_okx ( text, &uuid, __FILE__, __LINE__ );		\
+	} while ( 0 )
+
+/**
+ * Report a uuid_aton() failure test result
+ *
+ * @v text		Textual representation
+ * @v file		Test code file
+ * @v line		Test code line
+ */
+static void uuid_aton_fail_okx ( const char *text, const char *file,
+				 unsigned int line ) {
+	union uuid actual;
+
+	/* Attempt to parse address */
+	okx ( uuid_aton ( text, &actual ) != 0, file, line );
+}
+#define uuid_aton_fail_ok( text ) \
+	uuid_aton_fail_okx ( text, __FILE__, __LINE__ )
+
+/**
+ * Perform UUID self-tests
+ *
+ */
+static void uuid_test_exec ( void ) {
+
+	/* uuid_ntoa() tests */
+	uuid_ntoa_ok ( UUID ( 0x18725ca6, 0xd699, 0x4e4d, 0xb501,
+			      0xc3, 0x80, 0x91, 0xd2, 0xa4, 0x33 ),
+		       "18725ca6-d699-4e4d-b501-c38091d2a433" );
+	uuid_ntoa_ok ( UUID ( 0x1a969b23, 0xc7d5, 0x40fe, 0xb79a,
+			      0xc9, 0x2e, 0xa3, 0x4a ,0xb4, 0x5b ),
+		       "1a969b23-c7d5-40fe-b79a-c92ea34ab45b" );
+
+	/* uuid_aton() tests */
+	uuid_aton_ok ( "62b907a8-e1a7-460e-82f7-667d84270c84",
+		       UUID ( 0x62b907a8, 0xe1a7, 0x460e, 0x82f7,
+			      0x66, 0x7d, 0x84, 0x27, 0x0c, 0x84 ) );
+	uuid_aton_ok ( "F5D0349C-EF7C-4AD4-B40B-FC2E522A7327",
+		       UUID ( 0xf5d0349c, 0xef7c, 0x4ad4, 0xb40b,
+			      0xfc, 0x2e, 0x52, 0x2a, 0x73, 0x27 ) );
+	uuid_aton_ok ( "4edd80ff7b43465589a02b1e7cffa196",
+		       UUID ( 0x4edd80ff, 0x7b43, 0x4655, 0x89a0,
+			      0x2b, 0x1e, 0x7c, 0xff, 0xa1, 0x96 ) );
+
+	/* uuid_aton() failure tests */
+	uuid_aton_fail_ok ( "628d677b-cf38-471e-9ad9-c8a5d9220055b6" );
+	uuid_aton_fail_ok ( "5071ca26-fc5f-4580-887a-46d9a103e4" );
+	uuid_aton_fail_ok ( "453aee96:0fb5-4aeb-aecd-d060b2121218" );
+	uuid_aton_fail_ok ( "1ccb524a-b8b9-4b17-x5e2-7996867edc7d" );
+	uuid_aton_fail_ok ( "" );
+}
+
+/** UUID self-test */
+struct self_test uuid_test __self_test = {
+	.name = "uuid",
+	.exec = uuid_test_exec,
+};