[libvirt] [PATCH] Remove use of strncpy in qemudExtractMonitorPath.

[Daniel P. Berrange]

On Fri, Aug 07, 2009 at 11:06:28AM +0200, Chris Lalancette wrote:
> qemudExtractMonitorPath() was doing a VIR_ALLOC_N followed by a
> strncpy.  However, this isn't necessary; we can do the same thing
> using virAsprintf(), which is much safer.
> 
> Signed-off-by: Chris Lalancette <clalance at redhat.com>
> ---
>  src/qemu_driver.c |    7 ++++---
>  1 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/src/qemu_driver.c b/src/qemu_driver.c
> index 55a09f5..37fdec2 100644
> --- a/src/qemu_driver.c
> +++ b/src/qemu_driver.c
> @@ -1017,12 +1017,13 @@ qemudExtractMonitorPath(virConnectPtr conn,
>       */
>      while (*tmp) {
>          if (c_isspace(*tmp)) {
> -            if (VIR_ALLOC_N(*path, (tmp-dev)+1) < 0) {
> +            if (virAsprintf(path, "%s", dev) < 0) {
>                  virReportOOMError(conn);
>                  return -1;
>              }
> -            strncpy(*path, dev, (tmp-dev));
> -            (*path)[(tmp-dev)] = '\0';
> +            /* the last character is a \n, so back up one to overwrite */
> +            (*path)[tmp-dev] = '\0';
> +
>              /* ... now further update offset till we get EOL */
>              *offset = tmp - haystack;
>              return 0;

virAsprintf seems a little overkill to me - how about just
using  strndup(), which is equivalent to VIR_ALLOC_N + strncpy,
but with guarenteed null termination


Daniel
-- 
|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|