Transcript INF5060: Multimedia data communication using network processors

INF5060:
Multimedia data communication using network processors
ARP
8/10 - 2004
Assignment 5
 Extend the simple packet bridge from assignment 4 with ARP support
 build an ARP table to dynamically bind/map an IP address to a mac address and
an interface on the card
 check IP address and forward packet to correct interface
 be aware of broadcast loops
INF5060 – multimedia communication using network processors
2004 Carsten Griwodz & Pål Halvorsen
ARP Packet
Opcode:
Request: 1
Reply:
2
Sender MAC address: mandatory
MAC dest
MAC dest
MAS src
MAC src
type
… only for readability …
Hardware type = 1
Protocol type = 0x800
MACaddr len=6 Netaddr len=4
Opcode
Sender MAC address
Sender MAC address
Sender IP address
Sender IP address
Receiver MAC address
Receiver MAC address
Receiver IP address
Sender IP address: mandatory
Receiver MAC address
Request: 0
Reply: requester’s MAC address
Receiver IP address: mandatory
INF5060 – multimedia communication using network processors
2004 Carsten Griwodz & Pål Halvorsen
IXP1200
IXP1200
Broadcast problem
INF5060 – multimedia communication using network processors
2004 Carsten Griwodz & Pål Halvorsen
ARP caching
Most OSes do ARP caching
Our bridge does it for building and maintained a
spanning tree
Two proposed caches
Address-to-interface mapping
Last refresh cycle count (64 bit)
IP address (32 bit)
IF (32 bit)
Broadcast suppression
Last seen cycle count (64 bit)
IP source (32 bit)
MAC source (48 bit)
MAC dest (48 bit)
xbuf_alloc [$cyclect,2]
csr[read, $cyclect[0], CYCLE_CNT]
Microengine clock speed: 232 Mhz
xbuf_free[$cyclect]
INF5060 – multimedia communication using network processors
2004 Carsten Griwodz & Pål Halvorsen
Allocating cache memory
 Memory must be allocated by StrongARM
 Memory offset must be passed to microengines in shared
memory
 E.g.
e = RmMalloc(RM_SRAM, &ptr, n*4); space for n address-to-IF mapping entries
e = RmGetPhysOffset(RM_SRAM, ptr, &sram_offset);
e = RmMalloc(RM_SCRATCH, &ptrptr, 1); space for pointer to cache
e = RmGetPhysOffset(RM_SCRATCH, ptrptr, &sramptr_offset);
e = RmWrite(RM_SCRATCH, sramptr_offset, sram_offset, 0);
for( i=0; i<6; i++ ) {
sym.meNumber = i;
bzero(sym.name, MAX_SIZE_OF_IMPORTED_SYMBOL);
strncpy(sym.name, CACHE_PTR_STR, MAX_SIZE_OF_IMPORTED_SYMBOL);
sym.value = sramptr_offset;
e = RmUencPatchSymbol(i,&sym,1);
}
INF5060 – multimedia communication using network processors
2004 Carsten Griwodz & Pål Halvorsen