On 02/08/2016 03:28 AM, Samuel Thibault wrote:
> From: Yann Bordenave <meow@meowstars.org>
> 
> This patch adds parameters to manage some new options in the qemu -net
> command.
> Slirp IPv6 address, network prefix, and DNS IPv6 address can be given in
> argument to the qemu command.
> Defaults parameters are respectively fec0::2, fec0::, /64 and fec0::3.
> 
> Signed-off-by: Yann Bordenave <meow@meowstars.org>
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> ---
>  net/net.c        | 31 +++++++++++++++++++++++++++++++
>  net/slirp.c      | 50 ++++++++++++++++++++++++++++++++++++++++++++------
>  qapi-schema.json | 40 ++++++++++++++++++++++++++--------------
>  qemu-options.hx  | 18 ++++++++++++++++--
>  slirp/libslirp.h |  8 +++++---
>  slirp/slirp.c    | 16 +++++++++-------
>  6 files changed, 131 insertions(+), 32 deletions(-)
> 
> diff --git a/net/net.c b/net/net.c
> index c5e414f..0ececcb 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -1060,6 +1060,37 @@ int net_client_init(QemuOpts *opts, int is_netdev, Error **errp)
>      int ret = -1;
>  
>      {
> +        /* Parse convenience option format ip6-net=fec0::0[/64] */
> +        const char *ip6_net = qemu_opt_get(opts, "ip6-net");
> +
> +        if (ip6_net) {
> +            char buf[strlen(ip6_net)+1];

Spaces around binary '+'

> +
> +            if (get_str_sep(buf, sizeof(buf), &ip6_net, '/') < 0) {
> +                /* Default 64bit prefix length.  */
> +                qemu_opt_set(opts, "ip6-prefix", ip6_net, &error_abort);
> +                qemu_opt_set_number(opts, "ip6-prefixlen", 64, &error_abort);
> +            } else {
> +                /* User-specified prefix length.  */
> +                int len;
> +                char *end;
> +
> +                qemu_opt_set(opts, "ip6-prefix", buf, &error_abort);
> +                len = strtol(ip6_net, &end, 10);
> +
> +                if (*end != '\0') {
> +                    error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
> +                              "ip6-prefix", "a number");
> +                } else {
> +                    qemu_opt_set_number(opts, "ip6-prefixlen", len,
> +                                        &error_abort);
> +                }

Incorrect use of strtol() (you failed to check for overflow, which
requires priming errno to 0).  I recommend using qemu_strtol() instead,
as it does the grunt work for you and is harder to use incorrectly.

> +++ b/qapi-schema.json
> @@ -2399,6 +2399,14 @@
>  # @dnssearch: #optional list of DNS suffixes to search, passed as DHCP option
>  #             to the guest
>  #
> +# @ip6-prefix: #optional IPv6 network prefix (since 2.6)
> +#
> +# @ip6-prefixlen: #optional IPv6 network prefix length (since 2.6)

Would be worth mentioning the default values.

> +#
> +# @ip6-host: #optional guest-visible IPv6 address of the host (since 2.6)
> +#
> +# @ip6-dns: #optional guest-visible IPv6 address of the virtual nameserver (since 2.6)
> +#
>  # @smb: #optional root directory of the built-in SMB server
>  #
>  # @smbserver: #optional IP address of the built-in SMB server

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org