bin/54672: [PATCH] fix gcc 3.3 compiler warning for ifconfig(8)

[Lukas Ertl]

The following reply was made to PR bin/54672; it has been noted by GNATS.

From: Lukas Ertl <l.ertl at univie.ac.at>
To: Bruce Evans <bde at zeta.org.au>
Cc: FreeBSD-gnats-submit at freebsd.org, freebsd-bugs at freebsd.org
Subject: Re: bin/54672: [PATCH] fix gcc 3.3 compiler warning for ifconfig(8)
Date: Mon, 21 Jul 2003 13:51:23 +0200 (CEST)

 On Mon, 21 Jul 2003, Bruce Evans wrote:
 
 > On Sun, 20 Jul 2003, Lukas Ertl wrote:
 >
 > > first and last are both declared as u_short, which can't hold values la=
 rger
 > > then 0xffff, so the comparison isn't needed.
 >
 > This is machine-dependent.  u_short can hold values up to USHRT_MAX, whic=
 h
 > is >=3D 0xffff (perhaps strictly larger).
 >
 > There doesn't seem to be any good reason to use u_shorts; similar code in
 > at_getaddr() uses u_ints so it accidentally avoids the warning except on
 > machines with 16-bit u_ints.
 >
 > Using strtoul() as mentioned in the XXX before the above code would avoid
 > the warning less accidentally since 0xffff < ULONG_MAX on all machines.
 
 Well, would this patch be better:
 
 ---8<---
 Index: sbin/ifconfig/ifconfig.c
 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
 RCS file: /usr/local/bsdcvs/src/sbin/ifconfig/ifconfig.c,v
 retrieving revision 1.90
 diff -u -u -r1.90 ifconfig.c
 --- sbin/ifconfig/ifconfig.c=0928 Apr 2003 16:37:38 -0000=091.90
 +++ sbin/ifconfig/ifconfig.c=0921 Jul 2003 11:50:33 -0000
 @@ -1680,17 +1680,34 @@
  =09bcopy(LLADDR(&sdl), sa->sa_data, sdl.sdl_alen);
  }
 
 -/* XXX  FIXME -- should use strtoul for better parsing. */
  void
  setatrange(const char *range, int dummy __unused, int s,
      const struct afswtch *afp)
  {
 -=09u_short=09first =3D 123, last =3D 123;
 +=09u_int=09first =3D 123, last =3D 123;
 +=09char=09*p, *endptr;
 +
 +=09if ((p =3D strchr(range, '-')) =3D=3D NULL)
 +=09=09errx(1, "illegal range '%s'", range);
 +
 +=09*p =3D '\0';
 +=09p++;
 +
 +=09if ((*range =3D=3D '\0') || (*p =3D=3D '\0'))
 +=09=09errx(1, "illegal range '%s-%s'", range, p);
 +
 +=09first =3D strtoul(range, &endptr, 10);
 +=09if (endptr =3D=3D range || *endptr !=3D '\0')
 +=09=09errx(1, "illegal range '%s-%s'", range, p);
 +
 +=09last =3D strtoul(p, &endptr, 10);
 +=09if (endptr =3D=3D p || *endptr !=3D '\0')
 +=09=09errx(1, "illegal range '%s-%s'", range, p);
 +
 +=09if (first =3D=3D 0 || first > 0xffff || last =3D=3D 0 || last > 0xffff
 +=09    || first > last)
 +=09=09errx(1, "%s-%s: illegal net range: %u-%u", range, p, first, last);
 
 -=09if (sscanf(range, "%hu-%hu", &first, &last) !=3D 2
 -=09    || first =3D=3D 0 || first > 0xffff
 -=09    || last =3D=3D 0 || last > 0xffff || first > last)
 -=09=09errx(1, "%s: illegal net range: %u-%u", range, first, last);
  =09at_nr.nr_firstnet =3D htons(first);
  =09at_nr.nr_lastnet =3D htons(last);
  }
 ---8<---
 
 regards,
 le
 
 --=20
 Lukas Ertl                             eMail: l.ertl at univie.ac.at
 UNIX-Systemadministrator               Tel.:  (+43 1) 4277-14073
 Zentraler Informatikdienst (ZID)       Fax.:  (+43 1) 4277-9140
 der Universit=E4t Wien                   http://mailbox.univie.ac.at/~le/