From d2cc961c7312e18852ef016b4cfa7be02bbca725 Mon Sep 17 00:00:00 2001 From: Eric Andersen 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/inet') 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 #include -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; } -- cgit v1.2.3