Fix some bugs in ifconf():

- maintain space left correctly.  the pointer is advanced by the size
  of struct ifreq when length of address is small.
- single sizeof operator is enough to take the size of struct.
- the type of `sz' must be singed type since it is/was compared against to
  the variable which may become negative.
- no need to traverse rest of interfaces once we got an error.  note that
  the latter `break' statement was inside inner loop.
This commit is contained in:
enami 2007-06-01 09:35:47 +00:00
parent 4868ebda4e
commit 723ff30abc

View File

@ -1,4 +1,4 @@
/* $NetBSD: if.c,v 1.189 2007/05/31 02:56:50 christos Exp $ */
/* $NetBSD: if.c,v 1.190 2007/06/01 09:35:47 enami Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001 The NetBSD Foundation, Inc.
@ -97,7 +97,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.189 2007/05/31 02:56:50 christos Exp $");
__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.190 2007/06/01 09:35:47 enami Exp $");
#include "opt_inet.h"
@ -1617,17 +1617,14 @@ ifconf(u_long cmd, void *data)
struct ifnet *ifp;
struct ifaddr *ifa;
struct ifreq ifr, *ifrp;
int space = ifc->ifc_len, error = 0;
const size_t sz = offsetof(struct ifreq, ifr_ifru) +
sizeof(sizeof (struct sockaddr));
int sign;
int space, error = 0;
const int sz = offsetof(struct ifreq, ifr_ifru) +
sizeof(struct sockaddr);
if ((ifrp = ifc->ifc_req) == NULL) {
if ((ifrp = ifc->ifc_req) == NULL)
space = 0;
sign = -1;
} else {
sign = 1;
}
else
space = ifc->ifc_len;
IFNET_FOREACH(ifp) {
(void)strncpy(ifr.ifr_name, ifp->if_xname,
sizeof(ifr.ifr_name));
@ -1635,13 +1632,13 @@ ifconf(u_long cmd, void *data)
return ENAMETOOLONG;
if (TAILQ_EMPTY(&ifp->if_addrlist)) {
memset(&ifr.ifr_addr, 0, sizeof(ifr.ifr_addr));
if (ifrp != NULL && space >= sz) {
if (space >= sz) {
error = copyout(&ifr, ifrp, sz);
if (error != 0)
break;
return (error);
ifrp++;
}
space -= sz * sign;
space -= sizeof(struct ifreq);
continue;
}
@ -1649,35 +1646,32 @@ ifconf(u_long cmd, void *data)
struct sockaddr *sa = ifa->ifa_addr;
if (sa->sa_len <= sizeof(*sa)) {
ifr.ifr_addr = *sa;
if (ifrp != NULL && space >= sz) {
if (space >= sz) {
error = copyout(&ifr, ifrp, sz);
ifrp++;
}
space -= sizeof(struct ifreq);
} else {
space -= (sa->sa_len - sizeof(*sa)) * sign;
if (ifrp != NULL && space >= sz) {
error = copyout(&ifr, ifrp,
sizeof(ifr.ifr_name));
if (error == 0) {
error = copyout(sa,
&ifrp->ifr_addr,
sa->sa_len);
}
ifrp = (struct ifreq *)
(sa->sa_len +
(char *)&ifrp->ifr_addr);
}
space -= sa->sa_len - sizeof(*sa) + sz;
if (space < 0)
continue;
error = copyout(&ifr, ifrp,
sizeof(ifr.ifr_name));
if (error == 0)
error = copyout(sa,
&ifrp->ifr_addr, sa->sa_len);
ifrp = (struct ifreq *)
(sa->sa_len + (char *)&ifrp->ifr_addr);
}
if (error != 0)
break;
space -= sz * sign;
return (error);
}
}
if (ifrp != NULL)
ifc->ifc_len -= space;
else
ifc->ifc_len = space;
return error;
ifc->ifc_len = -space;
return (0);
}
/*