Re: rtentry and rtrequest

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.

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