Re: [RTnet-developers] SOCKET RAW

[Jan K. <jan...@we...>]

Jorge Almeida wrote:
> Jan,
>=20
> In attach i send you a diff file regarding the af_packet.c file where t=
he RAW=20
> SOCKET is implemented, similar to the DGRAM SOCKET.

Two general remarks, rest inlined below:

o The diff parameter "-p" makes the output more readable by adding the
  context of the change.

o Please avoid // comments (maybe except for temporary debug stuff)

>=20
> I've already run some tests on it and everything looks OK.
>=20
> Please run some more, or ask to (to some other interested person) and p=
ublish=20
> the results.
>=20

Do you have some test program? May an enhanced version of the existing
packet-socket demo with selectable mode? Would make it easier to start.

>=20
> Now i'm starting with the ETH_P_ALL to the protocol definition.
> Were, in the code, can i start to see the protocol filter implementatio=
n?
> And wath is the best thing to do regarding ETH_P_ALL? Remove from QUEUE=
 or=20
> copy the message from buffer and it still remains there? The second has=
 the=20
> problem of the queue grows undefined.=20
> Any suggestions?

See my earlier post:

http://www.mail-archive.com/rtnet-users%40lists.sourceforge.net/msg01279.=
html

This would make ETH_P_ALL not true ALL, but it would also not blow up
the current strict resource management scheme. Unless you are building a
packet sniffer, this should be fine for most use cases (and there is
already a sniffer interface).

>=20
>=20
> Thanks
>=20
>=20
>=20
> -----------------------------------------------------------------------=
-
>=20
> --- rtnet-0.9.4/stack/packet/af_packet.c	2006-08-06 19:23:36.000000000 =
+0100
> +++ rtnet-0.9.4/stack/packet/af_packet.c	2006-08-28 16:07:35.000000000 =
+0100
> @@ -89,7 +89,7 @@
> =20
>      rtdm_lock_get_irqsave(&sock->param_lock, context);
> =20
> -    /* release exisiting binding */
> +    /* release existing binding */
>      if ((pt->type !=3D 0) && ((ret =3D rtdev_remove_pack(pt)) < 0)) {
>          rtdm_lock_put_irqrestore(&sock->param_lock, context);
>          return ret;
> @@ -277,7 +277,7 @@
>      /* non-blocking receive? */
>      if (testbits(msg_flags, MSG_DONTWAIT))
>          timeout =3D -1;
> -
> +//     rt_printk("Packet:DEBUG: timeout %lld \n",timeout);
>      ret =3D rtdm_sem_timeddown(&sock->pending_sem, timeout, NULL);
>      if (unlikely(ret < 0)) {
>          if ((ret !=3D -EWOULDBLOCK) && (ret !=3D -ETIMEDOUT))
> @@ -313,10 +313,45 @@
>          copy_len =3D len;
>          msg->msg_flags |=3D MSG_TRUNC;
>      }
> +   =20
> +    if(sockctx->device->socket_type =3D=3D SOCK_DGRAM)
> +    {
> +//         rt_printk("Packet:DEBUG: SOCKET DGRAM SELECTED\n");
> +        /* copy the data */
> +        rt_memcpy_tokerneliovec(msg->msg_iov, skb->data, copy_len);
> +    }
> +    else if (sockctx->device->socket_type =3D=3D SOCK_RAW)
> +    {
> +        int nBufferLen =3D 0;
> +        int nI =3D 0;
> +        unsigned char puchBuffer[ETH_FRAME_LEN] =3D {0};
> +           =20
> +        memcpy((puchBuffer+nBufferLen), eth->h_dest,ETH_ALEN);
> +        nBufferLen +=3D ETH_ALEN;
> =20
> -    /* copy the data */
> -    rt_memcpy_tokerneliovec(msg->msg_iov, skb->data, copy_len);
> +        memcpy((puchBuffer+nBufferLen), eth->h_source,ETH_ALEN);
> +        nBufferLen +=3D ETH_ALEN;
> +
> +        memcpy((puchBuffer+nBufferLen), &(eth->h_proto),2);
> +        nBufferLen +=3D 2;
> =20
> +        memcpy((puchBuffer+nBufferLen), skb->data, copy_len);
> +        nBufferLen +=3D copy_len;
> +        /* start DEBUG purpouse*/
> +//         rt_printk("Message Received: ");
> +//         for(nI =3D 0; nI <nBufferLen ; nI++)
> +//             rt_printk(" %02X",puchBuffer[nI]);
> +//         rt_printk("\n");
> +        /* end DEBUG purpouse*/
> +        /* copy the data to user */  =20
> +        rt_memcpy_tokerneliovec(msg->msg_iov, puchBuffer, nBufferLen);=

> +        /* new buffer length*/
> +        real_len =3D nBufferLen;
> +    }
> +    else
> +    {
> +        rt_printk("Packet: Socket type Not Supported\n");
> +    }
>      if ((msg_flags & MSG_PEEK) =3D=3D 0) {
>          rtdev_dereference(skb->rtdev);
>          kfree_rtskb(skb);
> @@ -383,12 +418,38 @@
> =20
>      rtskb->rtdev    =3D rtdev;
>      rtskb->priority =3D sock->priority;
> -
> -    if (rtdev->hard_header) {
> -        ret =3D rtdev->hard_header(rtskb, rtdev, ntohs(sll->sll_protoc=
ol),
> -                                 sll->sll_addr, rtdev->dev_addr, rtskb=
->len);
> -        if (ret < 0)
> -            goto err;
> +    // SOCK_DGRAM
> +    if(sockctx->device->socket_type =3D=3D SOCK_DGRAM)
> +    {
> +//         rt_printk("Packet:DEBUG: SOCKET DGRAM SELECTED\n");
> +       =20
> +        if (rtdev->hard_header) {
> +            ret =3D rtdev->hard_header(rtskb, rtdev, ntohs(sll->sll_pr=
otocol),
> +                                    sll->sll_addr, rtdev->dev_addr, rt=
skb->len);
> +            if (ret < 0)
> +                goto err;
> +        }
> +    }
> +    // SOCK_RAW
> +    else if (sockctx->device->socket_type =3D=3D SOCK_RAW)
> +    {
> +//         rt_printk("Packet:DEBUG: SOCKET RAW SELECTED\n");
> +        unsigned char puchBuffer[ETH_FRAME_LEN];
> +       =20
> +        if (rtdev->hard_header) {
> +            ret =3D rtdev->hard_header(rtskb, rtdev, (rtskb->data+ETH_=
ALEN+ETH_ALEN),
> +                                     sll->sll_addr, (rtskb->data+ETH_A=
LEN), (rtskb->len - ETH_HLEN));
> +            if (ret < 0)
> +                goto err;
> +        }
> +        memcpy(puchBuffer,rtskb->data,rtskb->len);
> +        memcpy(rtskb->data,(puchBuffer+ETH_HLEN),(rtskb->len - ETH_HLE=
N));
> +        rtskb->len =3D rtskb->len - ETH_HLEN;
> +//         rt_printk("Packet:DEBUG: SOCKET RAW SELECTED and exit\n");
> +    }
> +    else
> +    {
> +        rt_printk("Packet: Socket type Not Supported\n");

This is debug output, isn't it? If you get here, you did something wrong
during socket setup. That would also simplify the test above to

  if (...socket_type =3D=3D SOCK_DGRAM) { } else { }.

>      }
> =20
>      if ((rtdev->flags & IFF_UP) !=3D 0) {
> @@ -409,8 +470,6 @@
>      return ret;
>  }
> =20
> -
> -
>  static struct rtdm_device   packet_proto_dev =3D {
>      struct_version:     RTDM_DEVICE_STRUCT_VER,
> =20
> @@ -430,7 +489,7 @@
>          ioctl_nrt:      rt_packet_ioctl,
>          recvmsg_rt:     rt_packet_recvmsg,
>          sendmsg_rt:     rt_packet_sendmsg
> -    },
> +},
> =20
>      device_class:       RTDM_CLASS_NETWORK,
>      device_sub_class:   RTDM_SUBCLASS_RTNET,
> @@ -443,15 +502,55 @@
>  };
> =20
> =20
> +static struct rtdm_device   raw_packet_proto_dev =3D {
> +    struct_version:     RTDM_DEVICE_STRUCT_VER,
> +
> +    device_flags:       RTDM_PROTOCOL_DEVICE,
> +    context_size:       sizeof(struct rtsocket),
> +
> +    protocol_family:    PF_PACKET,
> +    socket_type:        SOCK_RAW,
> +
> +    socket_rt:          rt_packet_socket,
> +    socket_nrt:         rt_packet_socket,
> +
> +    ops: {
> +        close_rt:       rt_packet_close,
> +        close_nrt:      rt_packet_close,
> +        ioctl_rt:       rt_packet_ioctl,
> +        ioctl_nrt:      rt_packet_ioctl,
> +        recvmsg_rt:     rt_packet_recvmsg,
> +        sendmsg_rt:     rt_packet_sendmsg
> +    },
> +
> +    device_class:       RTDM_CLASS_NETWORK,
> +    device_sub_class:   RTDM_SUBCLASS_RTNET,
> +    driver_name:        "rtrawpacket",

Driver name is still "rtpacket" (same binary).

> +    driver_version:     RTNET_RTDM_VER,
> +    peripheral_name:    "Real-Time Packet Socket Interface",
> +    provider_name:      rtnet_rtdm_provider_name,
> +
> +    proc_name:          "PACKET_RAW"
> +};
> +
> +
>  int __init rt_packet_proto_init(void)
>  {
> -    return rtdm_dev_register(&packet_proto_dev);
> +    int nReturn =3D -1;
> +    nReturn =3D rtdm_dev_register(&packet_proto_dev);
> +    if(nReturn !=3D 0)
> +        return nReturn;
> +//     rt_printk("DGRAM return =3D %d\n",nReturn);
> +    nReturn =3D rtdm_dev_register(&raw_packet_proto_dev);
> +//     rt_printk("RAW return =3D %d\n",nReturn);
> +    return nReturn;

Mmh, and what happens to the packet_proto_dev registration if
raw_packet_proto_dev goes South?

>  }
> =20
> =20
>  void rt_packet_proto_release(void)
>  {
>      rtdm_dev_unregister(&packet_proto_dev, 1000);
> +    rtdm_dev_unregister(&raw_packet_proto_dev, 1000);
>  }
> =20
> =20

Thanks for your contribution!

Jan