[PATCH 08/21] net: allow udp connections on specified network device

[Sam Ravnborg]

Hi Sasha.

On Fri, Nov 24, 2017 at 09:12:24AM +0100, Sascha Hauer wrote:
> This allows the DHCP code to configure specific network
> devices so that DHCP no longer depends on any "current"
> network device.
> 
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
>  include/net.h |  4 ++++
>  net/net.c     | 32 ++++++++++++++++++++------------
>  2 files changed, 24 insertions(+), 12 deletions(-)
> 
> diff --git a/include/net.h b/include/net.h
> index e75f64fe75..6788f14cb0 100644
> --- a/include/net.h
> +++ b/include/net.h
> @@ -443,6 +443,10 @@ static inline char *net_alloc_packet(void)
>  struct net_connection *net_udp_new(IPaddr_t dest, uint16_t dport,
>  		rx_handler_f *handler, void *ctx);
>  
> +struct net_connection *net_udp_eth_new(struct eth_device *edev, IPaddr_t dest,
> +                                       uint16_t dport, rx_handler_f *handler,
> +                                       void *ctx);
> +
>  struct net_connection *net_icmp_new(IPaddr_t dest, rx_handler_f *handler,
>  		void *ctx);
>  
> diff --git a/net/net.c b/net/net.c
> index 5f9535fc40..1d47bb449a 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -141,9 +141,8 @@ static void arp_handler(struct arprequest *arp)
>  	}
>  }
>  
> -static int arp_request(IPaddr_t dest, unsigned char *ether)
> +static int arp_request(struct eth_device *edev, IPaddr_t dest, unsigned char *ether)
>  {
> -	struct eth_device *edev = eth_get_current();
>  	char *pkt;
>  	struct arprequest *arp;
>  	uint64_t arp_start;
> @@ -288,15 +287,17 @@ IPaddr_t net_get_gateway(void)
>  
>  static LIST_HEAD(connection_list);
>  
> -static struct net_connection *net_new(IPaddr_t dest, rx_handler_f *handler,
> -		void *ctx)
> +static struct net_connection *net_new(struct eth_device *edev, IPaddr_t dest,
> +				      rx_handler_f *handler, void *ctx)
>  {
> -	struct eth_device *edev = eth_get_current();
>  	struct net_connection *con;
>  	int ret;
>  
> -	if (!edev)
> -		return ERR_PTR(-ENETDOWN);
> +	if (!edev) {
> +		edev = eth_get_current();
> +		if (!edev)
> +			return ERR_PTR(-ENETDOWN);
> +	}
>  
>  	if (!is_valid_ether_addr(edev->ethaddr)) {
>  		char str[sizeof("xx:xx:xx:xx:xx:xx")];
> @@ -325,7 +326,7 @@ static struct net_connection *net_new(IPaddr_t dest, rx_handler_f *handler,
>  	if (dest == 0xffffffff) {
>  		memset(con->et->et_dest, 0xff, 6);
>  	} else {
> -		ret = arp_request(dest, con->et->et_dest);
> +		ret = arp_request(edev, dest, con->et->et_dest);
>  		if (ret)
>  			goto out;
>  	}
> @@ -349,10 +350,11 @@ out:
>  	return ERR_PTR(ret);
>  }
>  
> -struct net_connection *net_udp_new(IPaddr_t dest, uint16_t dport,
> -		rx_handler_f *handler, void *ctx)
> +struct net_connection *net_udp_eth_new(struct eth_device *edev, IPaddr_t dest,
> +				       uint16_t dport, rx_handler_f *handler,
> +				       void *ctx)
>  {
> -	struct net_connection *con = net_new(dest, handler, ctx);
> +	struct net_connection *con = net_new(edev, 0xffffffff, handler, ctx);

I could not follow the code here.
But it looks strange that in this code snippet dest
was replaced by the magic 0xffffffff.

	Sam