Re: [Qemu-devel] [PATCHv7 9/9] qapi-schema, qemu-options & slirp: Adding Qemu options for IPv6 addresses

[Thomas Huth]

On 14.02.2016 18:47, Samuel Thibault wrote:
> From: Yann Bordenave <address@hidden>
> 
> 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 <address@hidden>
> Signed-off-by: Samuel Thibault <address@hidden>
> ---
>  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..a097971 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];
> +
> +            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.  */
> +                unsigned long len;
> +                int err;
> +
> +                qemu_opt_set(opts, "ip6-prefix", buf, &error_abort);
> +                err = qemu_strtoul(ip6_net, NULL, 10, &len);
> +
> +                if (err) {
> +                    error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
> +                              "ip6-prefix", "a number");
> +                } else {
> +                    qemu_opt_set_number(opts, "ip6-prefixlen", len,
> +                                        &error_abort);
> +                }
> +            }
> +            qemu_opt_unset(opts, "ip6-net");
> +        }
> +    }
> +
> +    {
>          OptsVisitor *ov = opts_visitor_new(opts);
>  
>          net_visit(opts_get_visitor(ov), is_netdev, &object, &err);
> diff --git a/net/slirp.c b/net/slirp.c
> index 6b51fbc..076dd27 100644
> --- a/net/slirp.c
> +++ b/net/slirp.c
> @@ -135,17 +135,23 @@ static NetClientInfo net_slirp_info = {
>  static int net_slirp_init(NetClientState *peer, const char *model,
>                            const char *name, int restricted,
>                            const char *vnetwork, const char *vhost,
> +                          const char *vprefix6, int vprefix6_len,
> +                          const char *vhost6,
>                            const char *vhostname, const char *tftp_export,
>                            const char *bootfile, const char *vdhcp_start,
> -                          const char *vnameserver, const char *smb_export,
> -                          const char *vsmbserver, const char **dnssearch)
> +                          const char *vnameserver, const char *vnameserver6,
> +                          const char *smb_export, const char *vsmbserver,
> +                          const char **dnssearch)
>  {
>      /* default settings according to historic slirp */
>      struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
>      struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 
> */
>      struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
> +    struct in6_addr ip6_prefix;
> +    struct in6_addr ip6_host;
>      struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
>      struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
> +    struct in6_addr ip6_dns;
>  #ifndef _WIN32
>      struct in_addr smbsrv = { .s_addr = 0 };
>  #endif
> @@ -213,6 +219,27 @@ static int net_slirp_init(NetClientState *peer, const 
> char *model,
>          return -1;
>      }
>  
> +    if (!vprefix6) {
> +        vprefix6 = "fec0::";
> +    }
> +    if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
> +        return -1;
> +    }
> +
> +    if (!vprefix6_len) {
> +        vprefix6_len = 64;
> +    }
> +    if (vprefix6_len < 0 || vprefix6_len > 128) {
> +        return -1;
> +    }
> +
> +    if (!vhost6) {
> +        vhost6 = "fec0::2";
> +    }
> +    if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
> +        return -1;
> +    }

The IPv4 code seems to have a sanity check that the vhost address is
within the same net as specified with the "net=" parameter... maybe the
IPv6 part should have that, too? Or use the prefix from "ip6-net=" here
if ip6-host has not been specified manually?

>      if (vnameserver && !inet_aton(vnameserver, &dns)) {
>          return -1;
>      }
> @@ -221,6 +248,13 @@ static int net_slirp_init(NetClientState *peer, const 
> char *model,
>          return -1;
>      }
>  
> +    if (!vnameserver6) {
> +        vnameserver6 = "fec0::3";
> +    }
> +    if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
> +        return -1;
> +    }

dito?

>      if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
>          return -1;
>      }
> @@ -243,8 +277,10 @@ static int net_slirp_init(NetClientState *peer, const 
> char *model,
>  
>      s = DO_UPCAST(SlirpState, nc, nc);
>  
> -    s->slirp = slirp_init(restricted, net, mask, host, vhostname,
> -                          tftp_export, bootfile, dhcp, dns, dnssearch, s);
> +    s->slirp = slirp_init(restricted, net, mask, host,
> +                          ip6_prefix, vprefix6_len, ip6_host,
> +                          vhostname, tftp_export, bootfile, dhcp,
> +                          dns, ip6_dns, dnssearch, s);
>      QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
>  
>      for (config = slirp_configs; config; config = config->next) {
> @@ -761,8 +797,10 @@ int net_init_slirp(const NetClientOptions *opts, const 
> char *name,
>      net_init_slirp_configs(user->guestfwd, 0);
>  
>      ret = net_slirp_init(peer, "user", name, user->q_restrict, vnet,
> -                         user->host, user->hostname, user->tftp,
> -                         user->bootfile, user->dhcpstart, user->dns, 
> user->smb,
> +                         user->host, user->ip6_prefix, user->ip6_prefixlen,
> +                         user->ip6_host, user->hostname, user->tftp,
> +                         user->bootfile, user->dhcpstart,
> +                         user->dns, user->ip6_dns, user->smb,
>                           user->smbserver, dnssearch);
>  
>      while (slirp_configs) {
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 8d04897..a62c2ec 100644
> --- a/qapi-schema.json
> +++ 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 (default is fec0::) (since 2.6)
> +#
> +# @ip6-prefixlen: #optional IPv6 network prefix length (default is 64) 
> (since 2.6)
> +#
> +# @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
> @@ -2412,20 +2420,24 @@
>  ##
>  { 'struct': 'NetdevUserOptions',
>    'data': {
> -    '*hostname':  'str',
> -    '*restrict':  'bool',
> -    '*ip':        'str',
> -    '*net':       'str',
> -    '*host':      'str',
> -    '*tftp':      'str',
> -    '*bootfile':  'str',
> -    '*dhcpstart': 'str',
> -    '*dns':       'str',
> -    '*dnssearch': ['String'],
> -    '*smb':       'str',
> -    '*smbserver': 'str',
> -    '*hostfwd':   ['String'],
> -    '*guestfwd':  ['String'] } }
> +    '*hostname':        'str',
> +    '*restrict':        'bool',
> +    '*ip':              'str',
> +    '*net':             'str',
> +    '*host':            'str',
> +    '*tftp':            'str',
> +    '*bootfile':        'str',
> +    '*dhcpstart':       'str',
> +    '*dns':             'str',
> +    '*dnssearch':       ['String'],
> +    '*ip6-prefix':      'str',
> +    '*ip6-prefixlen':   'int',
> +    '*ip6-host':        'str',
> +    '*ip6-dns':         'str',
> +    '*smb':             'str',
> +    '*smbserver':       'str',
> +    '*hostfwd':         ['String'],
> +    '*guestfwd':        ['String'] } }
>  
>  ##
>  # @NetdevTapOptions
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 733a194..de9e314 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1542,8 +1542,9 @@ DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
>  
>  DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
>  #ifdef CONFIG_SLIRP
> -    "-netdev user,id=str[,net=addr[/mask]][,host=addr][,restrict=on|off]\n"
> -    "         
> [,hostname=host][,dhcpstart=addr][,dns=addr][,dnssearch=domain][,tftp=dir]\n"
> +    "-netdev 
> user,id=str[,net=addr[/mask]][,host=addr][,ip6-net=addr[/int]]\n"
> +    "         
> [,ip6-host=addr][,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
> +    "         [,dns=addr][,ip6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
>      "         [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
>  #ifndef _WIN32
>                                               "[,smb=dir[,smbserver=addr]]\n"
> @@ -1700,6 +1701,14 @@ either in the form a.b.c.d or as number of valid 
> top-most bits. Default is
>  Specify the guest-visible address of the host. Default is the 2nd IP in the
>  guest network, i.e. x.x.x.2.
>  
> address@hidden address@hidden/@var{int}]
> +Set IPv6 network address the guest will see. Optionally specify the prefix
> +size, as number of valid top-most bits. Default is fec0::/64.
> +
> address@hidden address@hidden
> +Specify the guest-visible IPv6 address of the host. Default is the 2nd IPv6 
> in
> +the guest network, i.e. xxxx::2.

At least this does currently not match the code - the current default is
always fec0::2, no matter what has been specified for "ip6-net=...".

>  @item restrict=on|off
>  If this option is enabled, the guest will be isolated, i.e. it will not be
>  able to contact the host and no guest IP packets will be routed over the host
> @@ -1717,6 +1726,11 @@ Specify the guest-visible address of the virtual 
> nameserver. The address must
>  be different from the host address. Default is the 3rd IP in the guest 
> network,
>  i.e. x.x.x.3.
>  
> address@hidden address@hidden
> +Specify the guest-visible address of the IPv6 virtual nameserver. The address
> +must be different from the host address. Default is the 3rd IP in the guest
> +network, i.e. xxxx::3.

dito

>  @item address@hidden
>  Provides an entry for the domain-search list sent by the built-in
>  DHCP server. More than one domain suffix can be transmitted by specifying
...

The other parts of the patch look good to me.

 Thomas