IPBUF is laid out for frames we send, with the 12 byte TX descriptor in
front of the Ethernet header. A received frame starts with the Ethernet
header at uip_buf[0] and carries the RTL and VLAN tags after the
addresses, so IPBUF->ethhdr.src read the port mask and both VLAN fields
as a MAC. Every IP packet from the local network then replaced the
sender's ARP entry with that, and our replies went to an address nobody
has. The IP source address sits at the same offset in both layouts,
which is why the rest looked right.
Use BUF, the receive view uip_arp_arpin() already works from.
uip_arp_ipin() is an empty macro with its body under #if 0, both inherited
from the uIP import and untouched since. That leaves uip_arp_update()
reachable only from uip_arp_arpin(), so an entry is refreshed only by ARP
addressed to us and ages out after UIP_ARP_MAXAGE no matter how much traffic
passed over it.
When it goes, the next transmission to that host hits the miss path of
uip_arp_out(), which overwrites the packet in uip_buf with an ARP request and
returns. For TCP that costs a retransmission. For UDP nothing retransmits, and
handle_tx() sends the UDP connections through uip_arp_out() too, so the
datagram is lost.
The body could not be enabled as written: uip_len -= sizeof(struct uip_eth_hdr)
is a leftover from when UIP_LLH_LEN was 0. Here it is ETHER_HEADER_SIZE +
RTL_FRAME_DESC_SIZE and uip.c reads the IP header at uip_buf[UIP_LLH_LEN], so
uip_len has to keep the link layer in it. The rest of the function is sound.
We use the SoC's UUID to generate a fixed MAC for a particular
switch device. The MAC generated uses a Realtek prefix and then
is followed by 3 bytes genertaed from the first 3 bytes of the
UUID xored with the last byte in order to prevent being able
to deduce the UUID from the public MAC.
RTL has up to 3 SCL pins and up to 4 SDA pins. Lets allow configuring
I2C with individual BUS numbers instead of 0/1 I2C.
This enables support for devices where SCL line is not shared between
SFP modules. MUX registry is now initialized depending on needed
pin function.
More over, some SFP pins require special MUX settings, lets initialize
those depending on SFP configuration. This adds TX Disable pin,
which right now is set to low at startup.
Caveats:
- We may still override MUX registry later
- Not sure how to handle invalid bus definitions
- Without SFP is it fine to *not* initialize anything?
- Do to RAM limitation we do inititalize output GPIO to low
d00f
René van Dorst
logicog
diijkstra