rtentry and rtrequest

[Alan Garfield]

On Thu, 2007-04-19 at 21:53 +0400, Yar Tikhiy wrote:

> 1. Ping the Linux side with packets close to the MTU in size (ping
> -s), use different data patterns (ping -p), see with tcpdump -X if
> the data gets damaged.

Yeah I figured out. I wasn't handling mbuf chains properly so a bit of
the packet wasn't being put into the buffer. Fixed that now....

BUT!

Now I get this after I log in and try to output anything more than a few
characters (eg. ls -la) :-

----
Disconnecting: Corrupted MAC on input.
----


I'm sure it's something to do with how I'm doing the output. Does this
look sane?

----
static void
jnet_start_locked(struct ifnet* ifp)
{
        /* {{{ */
        struct jnet_softc *sc = ifp->if_softc;
        struct mbuf *m0, *m;
        int i, total_len;

        //device_printf(sc->dev, "jnet_start_locked() called.\n");

        JNET_ASSERT_LOCKED(sc);
        
outputloop:
        
        if ((&ifp->if_snd)->ifq_len == TX_QUEUE_SIZE ||
                        (&ifp->if_snd)->ifq_drv_len == TX_QUEUE_SIZE) {
        
                /* No room left. Set OACTIVE to tell everyone */
                ifp->if_drv_flags |= IFF_DRV_OACTIVE;
                return;         
        }
                        
        IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
                        
        if (m == 0) {
                
                /* 
                 * Space is still available in buffers so allow
                 * new packets to be added
                 */     
                ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
                return;
        }
                
        m0 = m; 

        /* set address counter to zero, then read the entire fifo */
        bus_space_write_1(sc->iot[PRS1_IO_OFFSET],
sc->ioh[PRS1_IO_OFFSET], PRS1_STATUS_OFFSET, 0x00);
                
        /* Output the IP_CHAR to tell SP the buffer is an IP packet */
        bus_space_write_1(sc->iot[PRS1_IO_OFFSET],
sc->ioh[PRS1_IO_OFFSET], PRS1_DATA_OFFSET, IP_CHAR);

        total_len = 0;

        // Loop over mbuf chain and output data to PRS1 DATA register -
Packet max length should
        // already be worked out by the upper layers
        while (m0) {
        
                if(m0->m_len) {
                        total_len += m0->m_len;

                        /* Output ethernet frame to prs buffer */
                        bus_space_write_multi_1(sc->iot[PRS1_IO_OFFSET],
sc->ioh[PRS1_IO_OFFSET],
                                        PRS1_DATA_OFFSET, mtod(m0,
unsigned char *), m0->m_len);

                }
                m0 = m0->m_next;
        }

        device_printf(sc->dev, "len: %i padding: %i total: %i\n",
                        total_len, FRAME_SIZE - total_len, total_len +
(FRAME_SIZE - total_len));

        /* Added padding to fill what's left of the buffer */
        for (i = total_len; i < FRAME_SIZE; i++) {
                bus_space_write_1(sc->iot[PRS1_IO_OFFSET],
sc->ioh[PRS1_IO_OFFSET], PRS1_DATA_OFFSET, 0x00);
        }

        m0 = m;

        BPF_MTAP(ifp, m0);

        m_freem(m0);

        /* Loop to top to possibly buffer more packets */
        goto outputloop;
}
----



> Nevertheless, it can be a reference driver working with real hardware
> for other folks to study.

It's simple enough once I figured out where the pitfalls are. :)

-A.