From d2cc961c7312e18852ef016b4cfa7be02bbca725 Mon Sep 17 00:00:00 2001
From: Eric Andersen <andersen@codepoet.org>
Date: Mon, 4 Aug 2003 19:03:33 +0000
Subject: Update inet_aton() to support an undocumented feature of inet_aton,
per UNIX Network Programming, Volume 1, second edition:
An undocumented feature of inet_aton is that if addrptr is
a null pointer, the function still performs it validation
of the input string, but does not store the result.
---
libc/inet/addr.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
(limited to 'libc')
diff --git a/libc/inet/addr.c b/libc/inet/addr.c
index df14fd09f..b4f8c9b87 100644
--- a/libc/inet/addr.c
+++ b/libc/inet/addr.c
@@ -24,20 +24,17 @@
#include <ctype.h>
#include <netinet/in.h>
-int inet_aton(const char *cp, struct in_addr *inp);
+int inet_aton(const char *cp, struct in_addr *addrptr);
#ifdef L_inet_aton
-int inet_aton(cp, inp)
+int inet_aton(cp, addrptr)
const char *cp;
-struct in_addr *inp;
+struct in_addr *addrptr;
{
unsigned long addr;
int value;
int part;
- if (!inp)
- return 0;
-
addr = 0;
for (part = 1; part <= 4; part++) {
@@ -65,7 +62,16 @@ struct in_addr *inp;
addr |= value;
}
- inp->s_addr = htonl(addr);
+ /* W. Richard Stevens in his book UNIX Network Programming,
+ * Volume 1, second edition, on page 71 says:
+ *
+ * An undocumented feature of inet_aton is that if addrptr is
+ * a null pointer, the function still performs it validation
+ * of the input string, but does not store the result.
+ */
+ if (addrptr) {
+ addrptr->s_addr = htonl(addr);
+ }
return 1;
}
--
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