[RFC,5/6] firewire net: IPv6 support (RFC3146).

Send packets for IPv6 multicast via GASP.

CC: Stephan Gatzka <stephan.gatzka@gmail.com>
CC: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
---
 drivers/firewire/Kconfig |    8 ++++++++
 drivers/firewire/net.c   |   13 ++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

On Jan 12 YOSHIFUJI Hideaki wrote:
> Send packets for IPv6 multicast via GASP.
> 
> CC: Stephan Gatzka <stephan.gatzka@gmail.com>
> CC: Stefan Richter <stefanr@s5r6.in-berlin.de>
> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> ---
>  drivers/firewire/Kconfig |    8 ++++++++
>  drivers/firewire/net.c   |   13 ++++++++++---
>  2 files changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/firewire/Kconfig b/drivers/firewire/Kconfig
> index 7224533..2e3018b 100644
> --- a/drivers/firewire/Kconfig
> +++ b/drivers/firewire/Kconfig
> @@ -51,9 +51,17 @@ config FIREWIRE_NET
>  	  other implementations of RFC 2734 as found on several operating
>  	  systems.  Multicast support is currently limited.
>  
> +	  Optional IPv6 support is available if you say Y here.
> +

This is a bit premature.  At least one thing which is still missing (also
missing in Stephan's patch from previous week) is the RFC 3146 clause 5
Configuration ROM entry.

>  	  To compile this driver as a module, say M here:  The module will be
>  	  called firewire-net.
>  
> +config FIREWIRE_NET_IPV6
> +	bool "IPv6 networking over 1394"
> +	depends on FIREWIRE_NET=y
> +	help
> +	  This enabless IPv6 over IEEE 1394, based on RFC 3146.
> +

I would rather like this to be like an invisible option which is
automatically on if IPV6=y || (IPV6=m && FIREWIRE_NET=m), and off
otherwise.

Or, as alluded to in my other post, it is going to be written such that

  - if IPV6=n, FIREWIRE_NET can be n, y, or m.  RFC 3146 support won't be
    built in in any case.

  - If IPV6=y, FIREWIRE_NET can be n, y, or m.  RFC 3146 support will be
    built in.

  - If IPV6=m, FIREWIRE_NET can be only n or m.  RFC 3146 support will be
    built in in the latter case.


>  config FIREWIRE_NOSY
>  	tristate "Nosy - a FireWire traffic sniffer for PCILynx cards"
>  	depends on PCI
> diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
> index 66c4f1c..a21d2f9 100644
> --- a/drivers/firewire/net.c
> +++ b/drivers/firewire/net.c
> @@ -27,6 +27,8 @@
>  #include <linux/spinlock.h>
>  
>  #include <asm/unaligned.h>
> +#include <linux/ipv6.h>
> +#include <net/addrconf.h>
>  #include <net/arp.h>
>  #include <net/firewire.h>
>  
> @@ -1329,13 +1331,18 @@ static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
>  	dg_size = skb->len;
>  
>  	/*
> -	 * Set the transmission type for the packet.  ARP packets and IP
> -	 * broadcast packets are sent via GASP.
> +	 * Set the transmission type for the packet.  ARP packets, IPv4
> +	 * broadcast packets, IPv6 multicast packets are sent via GASP.
>  	 */
>  	if (memcmp(hdr_buf.h_dest, net->broadcast, FWNET_ALEN) == 0
>  	    || proto == htons(ETH_P_ARP)
>  	    || (proto == htons(ETH_P_IP)
> -		&& IN_MULTICAST(ntohl(ip_hdr(skb)->daddr)))) {
> +		&& IN_MULTICAST(ntohl(ip_hdr(skb)->daddr)))
> +#if defined(CONFIG_FIREWIRE_NET_IPV6)
> +	    || (proto == htons(ETH_P_IPV6)
> +		&& ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
> +#endif
> +	   ) {
>  		max_payload        = dev->broadcast_xmt_max_payload;
>  		datagram_label_ptr = &dev->broadcast_xmt_datagramlabel;
>  

This hunk is fine with me.

> This is a bit premature.  At least one thing which is still missing (also
> missing in Stephan's patch from previous week) is the RFC 3146 clause 5
> Configuration ROM entry.
Argh, my fault. I already had it when I began to implement this stuff. 
It got lost somewhere...

No problem, I'll add it.

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

On Jan 12 Stefan Richter wrote:
> At least one thing which is still missing (also
> missing in Stephan's patch from previous week) is the RFC 3146 clause 5
> Configuration ROM entry.

Another thing:  As far as I understand, the current code assumes that
peers will use the same unicast_FIFO for IPv4 unicast as for IPv6
unicast.  This is not necessarily true.  Either firewire-net needs to
maintain two lists of peers (one for IPv4, another for IPv6), or it needs
to maintain two unicast_FIFOs per peer.

> Another thing:  As far as I understand, the current code assumes that
> peers will use the same unicast_FIFO for IPv4 unicast as for IPv6
> unicast.  This is not necessarily true.  Either firewire-net needs to
> maintain two lists of peers (one for IPv4, another for IPv6), or it needs
> to maintain two unicast_FIFOs per peer.
>

Thanks for pointing that out. I would go for two unicast_Fifos per peer.

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

On Jan 12 Stephan Gatzka wrote:
> 
> > Another thing:  As far as I understand, the current code assumes that
> > peers will use the same unicast_FIFO for IPv4 unicast as for IPv6
> > unicast.  This is not necessarily true.  Either firewire-net needs to
> > maintain two lists of peers (one for IPv4, another for IPv6), or it needs
> > to maintain two unicast_FIFOs per peer.
> >
> 
> Thanks for pointing that out. I would go for two unicast_Fifos per peer.

Indeed.  Plus, if we look up an IPv6 peer whose IPv6 unicast_FIFO is as
yet unkown but whose IPv4 unicast_FIFO is already known, we could
optimistically use the latter until we learn the former.  And vice versa.