git: 491263d7a640 - main - ping: Avoid magic numbers

From: Mark Johnston <markj_at_FreeBSD.org>
Date: Fri, 17 Mar 2023 13:29:19 UTC
The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=491263d7a640a85a6be40fd0c0a9397d072f0847

commit 491263d7a640a85a6be40fd0c0a9397d072f0847
Author:     Jose Luis Duran <jlduran@gmail.com>
AuthorDate: 2023-03-17 13:24:44 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2023-03-17 13:24:44 +0000

    ping: Avoid magic numbers
    
    The sizeof(struct ip) is 20.
    The sizeof(struct in_addr) is 4.
    
    No functional change intended.
    
    Reviewed by:    asomers, markj
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D39125
---
 sbin/ping/ping.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sbin/ping/ping.c b/sbin/ping/ping.c
index 6e069adfecfa..fe319bfb70a5 100644
--- a/sbin/ping/ping.c
+++ b/sbin/ping/ping.c
@@ -1670,7 +1670,7 @@ pr_iph(struct ip *ip)
 	int hlen;
 
 	hlen = ip->ip_hl << 2;
-	cp = (u_char *)ip + 20;		/* point to options */
+	cp = (u_char *)ip + sizeof(struct ip);		/* point to options */
 
 	(void)printf("Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst\n");
 	(void)printf(" %1x  %1x  %02x %04x %04x",
@@ -1686,7 +1686,7 @@ pr_iph(struct ip *ip)
 	memcpy(&ina, &ip->ip_dst.s_addr, sizeof ina);
 	(void)printf(" %s ", inet_ntoa(ina));
 	/* dump any option bytes */
-	while (hlen-- > 20) {
+	while (hlen-- > (int)sizeof(struct ip)) {
 		(void)printf("%02x", *cp++);
 	}
 	(void)putchar('\n');
@@ -1706,7 +1706,7 @@ pr_addr(struct in_addr ina)
 	if (options & F_NUMERIC)
 		return inet_ntoa(ina);
 
-	hp = cap_gethostbyaddr(capdns, (char *)&ina, 4, AF_INET);
+	hp = cap_gethostbyaddr(capdns, (char *)&ina, sizeof(ina), AF_INET);
 
 	if (hp == NULL)
 		return inet_ntoa(ina);