[libvirt] [PATCH 06/28] util: allow calling virSocketAddrGetIPPrefix with NULL netmask or address

[John Ferlan]

On 06/22/2016 01:37 PM, Laine Stump wrote:
> There are times when we don't have a netmask pointer to give to
> virSocketAddrGetIPPrefix() (e.g. the IP addresses in domain interfaces
> only have a prefix, no netmask), but it would have caused a segv if we
> called it with NULL instead of a pointer to a netmask. This patch
> qualifies the code that would use the netmask or address pointers to
> check for NULL first.
> ---
>  src/util/virsocketaddr.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 

According to how I read the commit message, "today" it could only be
possible to have a NULL netmask if prefix was set.

If prefix was set, then the following code returns prefix immediately.

So I don't have anything against the extra checks - perhaps a few extra
words either in comments or commit regarding is something existing or
something that could be a truism in the future where prefix == 0 and
either netmask or address is NULL.

Of course I have a feeling I'm being set up for something soon ;-)

ACK -

John
> diff --git a/src/util/virsocketaddr.c b/src/util/virsocketaddr.c
> index 12fe96a..33b1e9e 100644
> --- a/src/util/virsocketaddr.c
> +++ b/src/util/virsocketaddr.c
> @@ -1,5 +1,5 @@
>  /*
> - * Copyright (C) 2009-2015 Red Hat, Inc.
> + * Copyright (C) 2009-2016 Red Hat, Inc.
>   *
>   * This library is free software; you can redistribute it and/or
>   * modify it under the terms of the GNU Lesser General Public
> @@ -1026,9 +1026,9 @@ virSocketAddrGetIPPrefix(const virSocketAddr *address,
>  {
>      if (prefix > 0) {
>          return prefix;
> -    } else if (VIR_SOCKET_ADDR_VALID(netmask)) {
> +    } else if (netmask && VIR_SOCKET_ADDR_VALID(netmask)) {
>          return virSocketAddrGetNumNetmaskBits(netmask);
> -    } else if (VIR_SOCKET_ADDR_IS_FAMILY(address, AF_INET)) {
> +    } else if (address && VIR_SOCKET_ADDR_IS_FAMILY(address, AF_INET)) {
>          /* Return the natural prefix for the network's ip address.
>           * On Linux we could use the IN_CLASSx() macros, but those
>           * aren't guaranteed on all platforms, so we just deal with
> @@ -1053,7 +1053,7 @@ virSocketAddrGetIPPrefix(const virSocketAddr *address,
>              return 24;
>          }
>          return -1;
> -    } else if (VIR_SOCKET_ADDR_IS_FAMILY(address, AF_INET6)) {
> +    } else if (address && VIR_SOCKET_ADDR_IS_FAMILY(address, AF_INET6)) {
>          if (virSocketAddrIsWildcard(address))
>              return 0;
>          return 64;
>