[U-Boot] [RFC PATCH v3 09/14] dm: eth: Add ARP and PING response to sandbox driver

[Joe Hershberger <joe.hershberger@gmail.com>]

On Sun, Feb 15, 2015 at 9:49 AM, Simon Glass <sjg@chromium.org> wrote:
>
> Hi Joe,
>
> On 10 February 2015 at 18:30, Joe Hershberger <joe.hershberger@ni.com>
wrote:
> > The sandbox driver will now generate response traffic to exercise the
> > ping command even when no network exists.  This allows the basic data
> > pathways of the DM to be tested.
> >
> > Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
> > Reviewed-by: Simon Glass <sjg@chromium.org>
> > ---
> >
> > Changes in v3:
> > -Prevent a crash if memory is not allocated
> >
> > Changes in v2:
> > -Change printfs to debug in sandbox driver
> > -Move static data to priv
> > -Move fake hwaddr to the device tree
> >
> >  arch/sandbox/dts/sandbox.dts |   1 +
> >  drivers/net/sandbox.c        | 101
+++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 102 insertions(+)
> >
> > diff --git a/arch/sandbox/dts/sandbox.dts b/arch/sandbox/dts/sandbox.dts
> > index 502eb3d..ba635e8 100644
> > --- a/arch/sandbox/dts/sandbox.dts
> > +++ b/arch/sandbox/dts/sandbox.dts
> > @@ -186,5 +186,6 @@
> >         eth at 10002000 {
> >                 compatible = "sandbox,eth";
> >                 reg = <0x10002000 0x1000>;
> > +               fake-host-hwaddr = <0x00 0x00 0x66 0x44 0x22 0x00>;
> >         };
> >  };
> > diff --git a/drivers/net/sandbox.c b/drivers/net/sandbox.c
> > index 2a2ad41..f9fa1a1 100644
> > --- a/drivers/net/sandbox.c
> > +++ b/drivers/net/sandbox.c
> > @@ -15,22 +15,121 @@
> >
> >  DECLARE_GLOBAL_DATA_PTR;
> >
> > +struct eth_sandbox_priv {
> > +       uchar fake_host_hwaddr[ARP_HLEN];
> > +       IPaddr_t fake_host_ipaddr;
> > +       uchar recv_packet_buffer[PKTSIZE];
> > +       int recv_packet_length;
> > +};
> > +
> >  static int sb_eth_init(struct udevice *dev, bd_t *bis)
> >  {
> >         debug("eth_sandbox: Init\n");
> >
> > +       struct eth_sandbox_priv *priv = dev->priv;
> > +       u32 int_array[ARP_HLEN];
> > +       int i;
> > +
> > +       if (!priv)
> > +               return -EINVAL;
>
> How can this happen?

If I recall this was happening when the probe failed due to being unable to
find a MAC address.  This meant that the device was not active when the
init was called on it.  I believe I later remedied it by checking that
the DM_FLAG_ACTIVATED was set, so this check is probably not needed any
longer.

Is there a way in DM to iterate through only those devices that have been
successfully probed or is it my responsibility to check activated before
using any ops?

> > +
> > +       fdtdec_get_int_array(gd->fdt_blob, dev->of_offset,
"fake-host-hwaddr",
> > +                            int_array, ARP_HLEN);
> > +       for (i = 0; i < ARP_HLEN; i++)
> > +               priv->fake_host_hwaddr[i] = (uchar)int_array[i];
> > +
> >         return 0;
> >  }
> >
> >  static int sb_eth_send(struct udevice *dev, void *packet, int length)
> >  {
> >         debug("eth_sandbox: Send packet %d\n", length);
> > +       struct eth_sandbox_priv *priv = dev->priv;
> > +       struct ethernet_hdr *eth = packet;
> > +
> > +       if (ntohs(eth->et_protlen) == PROT_ARP) {
> > +               struct arp_hdr *arp = packet + ETHER_HDR_SIZE;
> > +               if (ntohs(arp->ar_op) == ARPOP_REQUEST) {
> > +                       /* store this as the assumed IP of the fake
host */
> > +                       priv->fake_host_ipaddr =
NetReadIP(&arp->ar_tpa);
> > +                       /* Formulate a fake response */
> > +                       struct ethernet_hdr *eth_recv =
> > +                               (void *)priv->recv_packet_buffer;
> > +                       memcpy(eth_recv->et_dest, eth->et_src,
ARP_HLEN);
> > +                       memcpy(eth_recv->et_src, priv->fake_host_hwaddr,
> > +                              ARP_HLEN);
> > +                       eth_recv->et_protlen = htons(PROT_ARP);
> > +
> > +                       struct arp_hdr *arp_recv =
> > +                               (void *)priv->recv_packet_buffer +
> > +                               ETHER_HDR_SIZE;
> > +                       arp_recv->ar_hrd = htons(ARP_ETHER);
> > +                       arp_recv->ar_pro = htons(PROT_IP);
> > +                       arp_recv->ar_hln = ARP_HLEN;
> > +                       arp_recv->ar_pln = ARP_PLEN;
> > +                       arp_recv->ar_op = htons(ARPOP_REPLY);
> > +                       memcpy(&arp_recv->ar_sha,
priv->fake_host_hwaddr,
> > +                              ARP_HLEN);
> > +                       NetWriteIP(&arp_recv->ar_spa,
priv->fake_host_ipaddr);
> > +                       memcpy(&arp_recv->ar_tha, &arp->ar_sha,
ARP_HLEN);
> > +                       NetCopyIP(&arp_recv->ar_tpa, &arp->ar_spa);
> > +
> > +                       priv->recv_packet_length = ETHER_HDR_SIZE +
> > +                               ARP_HDR_SIZE;
> > +               }
> > +       } else if (ntohs(eth->et_protlen) == PROT_IP) {
> > +               struct ip_udp_hdr *ip = packet + ETHER_HDR_SIZE;
> > +               if (ip->ip_p == IPPROTO_ICMP) {
> > +                       struct icmp_hdr *icmp = (struct icmp_hdr
*)&ip->udp_src;
> > +                       if (icmp->type == ICMP_ECHO_REQUEST) {
> > +                               /* reply to the ping */
> > +                               memcpy(priv->recv_packet_buffer, packet,
> > +                                      length);
> > +                               struct ethernet_hdr *eth_recv =
> > +                                       (void
*)priv->recv_packet_buffer;
> > +                               struct ip_udp_hdr *ipr =
> > +                                       (void
*)priv->recv_packet_buffer +
> > +                                       ETHER_HDR_SIZE;
> > +                               struct icmp_hdr *icmpr =
> > +                                       (struct icmp_hdr
*)&ipr->udp_src;
> > +                               memcpy(eth_recv->et_dest, eth->et_src,
> > +                                      ARP_HLEN);
> > +                               memcpy(eth_recv->et_src,
priv->fake_host_hwaddr,
> > +                                      ARP_HLEN);
> > +                               ipr->ip_sum = 0;
> > +                               ipr->ip_off = 0;
> > +                               NetCopyIP((void *)&ipr->ip_dst,
&ip->ip_src);
> > +                               NetWriteIP((void *)&ipr->ip_src,
> > +                                          priv->fake_host_ipaddr);
> > +                               ipr->ip_sum = ~NetCksum((uchar *)ipr,
> > +                                       IP_HDR_SIZE >> 1);
> > +
> > +                               icmpr->type = ICMP_ECHO_REPLY;
> > +                               icmpr->checksum = 0;
> > +                               icmpr->checksum = ~NetCksum((uchar
*)icmpr,
> > +                                       (length - ETHER_HDR_SIZE -
> > +                                               IP_HDR_SIZE) >> 1);
> > +
> > +                               priv->recv_packet_length = length;
> > +                       }
> > +               }
> > +       }
> >
> >         return 0;
> >  }
> >
> >  static int sb_eth_recv(struct udevice *dev)
> >  {
> > +       struct eth_sandbox_priv *priv = dev->priv;
> > +
> > +       if (priv && priv->recv_packet_length) {
> > +               int lcl_recv_packet_length = priv->recv_packet_length;
> > +               debug("eth_sandbox: received packet %d\n",
> > +                     priv->recv_packet_length);
> > +               priv->recv_packet_length = 0;
> > +               NetReceive((void *)priv->recv_packet_buffer,
> > +                          lcl_recv_packet_length);
> > +       }
> >         return 0;
> >  }
> >
> > @@ -42,6 +141,7 @@ static void sb_eth_halt(struct udevice *dev)
> >  static int sb_eth_write_hwaddr(struct udevice *dev)
> >  {
> >         struct eth_pdata *pdata = dev->platdata;
> > +
> >         debug("eth_sandbox %s: Write HW ADDR - %pM\n", dev->name,
> >               pdata->enetaddr);
> >         return 0;
> > @@ -82,5 +182,6 @@ U_BOOT_DRIVER(eth_sandbox) = {
> >         .ofdata_to_platdata = of_match_ptr(sb_eth_ofdata_to_platdata),
> >         .remove = sb_eth_remove,
> >         .ops    = &sb_eth_ops,
> > +       .priv_auto_alloc_size = sizeof(struct eth_sandbox_priv),
> >         .platdata_auto_alloc_size = sizeof(struct eth_pdata),
> >  };
> > --
> > 1.7.11.5
> >
>
> Regards,
> Simon
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