From 7696a120b453b8d8d5f5187d11baa48ad1f8e96f Mon Sep 17 00:00:00 2001
From: krw <krw@openbsd.org>
Date: Sat, 28 Aug 2021 11:55:17 +0000
Subject: [PATCH] Add hex_octet() so the strtol(..,16) dance is done in just
 one place.

Allows single-digit partition id's in '-b' as a side benefit.
---
 sbin/fdisk/cmd.c   | 30 ++++++++++--------------------
 sbin/fdisk/fdisk.c | 11 +++++------
 sbin/fdisk/misc.c  | 20 +++++++++++++++++++-
 sbin/fdisk/misc.h  |  3 ++-
 4 files changed, 36 insertions(+), 28 deletions(-)

diff --git a/sbin/fdisk/cmd.c b/sbin/fdisk/cmd.c
index abcba16ea5e..0eb738e9771 100644
--- a/sbin/fdisk/cmd.c
+++ b/sbin/fdisk/cmd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cmd.c,v 1.140 2021/08/24 12:34:04 krw Exp $	*/
+/*	$OpenBSD: cmd.c,v 1.141 2021/08/28 11:55:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -607,11 +607,13 @@ ask_pid(const int dflt, struct uuid *guid)
 	char			lbuf[100], *cp;
 	int			num = -1, status;
 
-	do {
-		printf("Partition id ('0' to disable) [01 - FF]: [%X] ", dflt);
+	for (;;) {
+		printf("Partition id ('0' to disable) [01 - FF]: [%02X] ", dflt);
 		printf("(? for help) ");
 		string_from_line(lbuf, sizeof(lbuf), TRIMMED);
 
+		if (strlen(lbuf) == 0)
+			return dflt;
 		if (strcmp(lbuf, "?") == 0) {
 			PRT_printall();
 			continue;
@@ -623,24 +625,12 @@ ask_pid(const int dflt, struct uuid *guid)
 				return 0x100;
 		}
 
-		/* Convert */
-		cp = lbuf;
-		num = strtol(lbuf, &cp, 16);
+		num = hex_octet(lbuf);
+		if (num != -1)
+			return num;
 
-		/* Make sure only number present */
-		if (cp == lbuf)
-			num = dflt;
-		if (*cp != '\0') {
-			printf("'%s' is not a valid number.\n", lbuf);
-			num = -1;
-		} else if (num == 0) {
-			break;
-		} else if (num < 0 || num > 0xff) {
-			printf("'%x' is out of range.\n", num);
-		}
-	} while (num < 0 || num > 0xff);
-
-	return num;
+		printf("'%s' is not a valid partition id.\n", lbuf);
+	}
 }
 
 char *
diff --git a/sbin/fdisk/fdisk.c b/sbin/fdisk/fdisk.c
index fa045d261ad..af57c767d15 100644
--- a/sbin/fdisk/fdisk.c
+++ b/sbin/fdisk/fdisk.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fdisk.c,v 1.134 2021/08/10 18:17:48 krw Exp $	*/
+/*	$OpenBSD: fdisk.c,v 1.135 2021/08/28 11:55:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -210,8 +210,8 @@ parse_bootprt(const char *arg)
 {
 	const char		*errstr;
 	char			*poffset, *ptype;
+	int			 partitiontype;
 	uint32_t		 blockcount, blockoffset;
-	uint8_t			 partitiontype;
 
 	blockoffset = BLOCKALIGNMENT;
 	partitiontype = DOSPTYP_EFISYS;
@@ -244,10 +244,9 @@ parse_bootprt(const char *arg)
 	if (ptype == NULL)
 		goto done;
 
-	if (strlen(ptype) != 2 || !(isxdigit(*ptype) && isxdigit(*(ptype + 1))))
-		errx(1, "Block type is not 2 digit hex value");
-
-	partitiontype = strtol(ptype, NULL, 16);
+	partitiontype = hex_octet(ptype);
+	if (partitiontype == -1)
+		errx(1, "Block type is not a 1-2 digit hex value");
 
  done:
 	disk.dk_bootprt.prt_ns = blockcount;
diff --git a/sbin/fdisk/misc.c b/sbin/fdisk/misc.c
index 91b191f0db3..ce349826f53 100644
--- a/sbin/fdisk/misc.c
+++ b/sbin/fdisk/misc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: misc.c,v 1.81 2021/08/24 12:34:04 krw Exp $	*/
+/*	$OpenBSD: misc.c,v 1.82 2021/08/28 11:55:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -265,3 +265,21 @@ string_to_utf16le(const char *ch)
 
 	return utf;
 }
+
+int
+hex_octet(char *buf)
+{
+	char			*cp;
+	long			 num;
+
+	cp = buf;
+	num = strtol(buf, &cp, 16);
+
+	if (cp == buf || *cp != '\0')
+		return -1;
+
+	if (num < 0 || num > 0xff)
+		return -1;
+
+	return num;
+}
diff --git a/sbin/fdisk/misc.h b/sbin/fdisk/misc.h
index 380b512ba8a..1b82046e043 100644
--- a/sbin/fdisk/misc.h
+++ b/sbin/fdisk/misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: misc.h,v 1.43 2021/08/24 12:55:06 krw Exp $	*/
+/*	$OpenBSD: misc.h,v 1.44 2021/08/28 11:55:17 krw Exp $	*/
 
 /*
  * Copyright (c) 1997 Tobias Weingartner
@@ -38,6 +38,7 @@ extern struct unit_type		unit_types[];
 int		 unit_lookup(const char *);
 void		 string_from_line(char *, const size_t, const int);
 int		 ask_yn(const char *);
+int		 hex_octet(char *);
 uint64_t	 getuint64(const char *, uint64_t, const uint64_t, const uint64_t);
 char		*utf16le_to_string(const uint16_t *);
 uint16_t	*string_to_utf16le(const char *);
-- 
2.20.1