basic.p4 aciklamali cozumu
rev.1
This commit is contained in:
parent
01ed2c499d
commit
e98b920436
@ -4,10 +4,6 @@
|
||||
|
||||
const bit<16> TYPE_IPV4 = 0x800;
|
||||
|
||||
/*************************************************************************
|
||||
*********************** H E A D E R S ***********************************
|
||||
*************************************************************************/
|
||||
|
||||
typedef bit<9> egressSpec_t;
|
||||
typedef bit<48> macAddr_t;
|
||||
typedef bit<32> ip4Addr_t;
|
||||
@ -42,35 +38,36 @@ struct headers {
|
||||
ipv4_t ipv4;
|
||||
}
|
||||
|
||||
/*************************************************************************
|
||||
*********************** P A R S E R ***********************************
|
||||
*************************************************************************/
|
||||
|
||||
parser MyParser(packet_in packet,
|
||||
out headers hdr,
|
||||
inout metadata meta,
|
||||
inout standard_metadata_t standard_metadata) {
|
||||
|
||||
/* each IPv4 thing is wrapped in Ethernet headers so the state is parse_ether
|
||||
by default */
|
||||
|
||||
state start {
|
||||
/* TODO: add parser logic */
|
||||
transition parse_ether;
|
||||
}
|
||||
|
||||
state parse_ether {
|
||||
packet.extract(hdr.ethernet);
|
||||
transition select(hdr.ethernet.etherType) {
|
||||
TYPE_IPV4: parse_ipv4;
|
||||
default: accept;
|
||||
}
|
||||
}
|
||||
|
||||
state parse_ipv4 {
|
||||
packet.extract(hdr.ipv4);
|
||||
transition accept;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/*************************************************************************
|
||||
************ C H E C K S U M V E R I F I C A T I O N *************
|
||||
*************************************************************************/
|
||||
|
||||
control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
|
||||
apply { }
|
||||
}
|
||||
|
||||
|
||||
/*************************************************************************
|
||||
************** I N G R E S S P R O C E S S I N G *******************
|
||||
*************************************************************************/
|
||||
|
||||
control MyIngress(inout headers hdr,
|
||||
inout metadata meta,
|
||||
inout standard_metadata_t standard_metadata) {
|
||||
@ -79,9 +76,30 @@ control MyIngress(inout headers hdr,
|
||||
}
|
||||
|
||||
action ipv4_forward(macAddr_t dstAddr, egressSpec_t port) {
|
||||
/* TODO: fill out code in action body */
|
||||
/* bu satiri aciklamaya calisirken switch'lerin portlarina bagli cihazlarin
|
||||
MAC adreslerini nasil ogrendigini ve nasil sakladigini arastirdim. takip eden ipv4_lpm kismi bu muammanin yanitini verecek. */
|
||||
/* disari yonlu paketin switch'in hangi portundan ayrilmasi gerektigi ayarlanir */
|
||||
standard_metadata.egress_spec = port;
|
||||
|
||||
/* paketin kaynagi artik biziz, srcAddr header'dan dstAddr olarak ayarlanir */
|
||||
hdr.ethernet.srcAddr = hdr.ethernet.dstAddr;
|
||||
|
||||
/* hedef adres, bir sonraki hop'un alicisi olarak ayarlanir */
|
||||
hdr.ethernet.dstAddr = dstAddr;
|
||||
|
||||
hdr.ipv4.ttl = hdr.ipv4.ttl - 1;
|
||||
}
|
||||
|
||||
/* burasi cokomelli: LPM "Longest Prefix Match"in kisaltmasi
|
||||
IP yonlendirmede kullanilan bir teknik. Verilen bir IP adres icin hangi
|
||||
(cihaz MAC'i - port) demetinin kullanilacagini seciyor.
|
||||
|
||||
tablonun kendisi ise IP_prefix : (MAC, port) seklinde bir veri yapisi
|
||||
cunku IP_prefix aslinda bir IP agini ifade ediyor (10.0.1.0/24 gibi)
|
||||
|
||||
biz de burada hedef IPv4 adresimizi LPM tablosundan esleyerek hangi
|
||||
porttan cikacagimizi belirliyor ya da tabloda olmayan bir yol sayesinde
|
||||
o paketi dropluyoruz (cunku bagli hicbir cihaz o yola sahip degil) */
|
||||
table ipv4_lpm {
|
||||
key = {
|
||||
hdr.ipv4.dstAddr: lpm;
|
||||
@ -96,27 +114,23 @@ control MyIngress(inout headers hdr,
|
||||
}
|
||||
|
||||
apply {
|
||||
/* TODO: fix ingress control logic
|
||||
* - ipv4_lpm should be applied only when IPv4 header is valid
|
||||
*/
|
||||
ipv4_lpm.apply();
|
||||
/* buradaki basta sihirli gorunen isValid, P4 tarafindan tanimlanan ve
|
||||
bir header'in duzgunce parse edilip pakette yer aldigini dogrulayan bir
|
||||
fonksiyonmus. */
|
||||
/* eger elimizdeki paket IPv4 paketi ise LPM tablosundaki kurallar
|
||||
uygulanacak. */
|
||||
if (hdr.ipv4.isValid()) {
|
||||
ipv4_lpm.apply();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*************************************************************************
|
||||
**************** E G R E S S P R O C E S S I N G *******************
|
||||
*************************************************************************/
|
||||
|
||||
control MyEgress(inout headers hdr,
|
||||
inout metadata meta,
|
||||
inout standard_metadata_t standard_metadata) {
|
||||
apply { }
|
||||
}
|
||||
|
||||
/*************************************************************************
|
||||
************* C H E C K S U M C O M P U T A T I O N **************
|
||||
*************************************************************************/
|
||||
|
||||
control MyComputeChecksum(inout headers hdr, inout metadata meta) {
|
||||
apply {
|
||||
update_checksum(
|
||||
@ -137,21 +151,14 @@ control MyComputeChecksum(inout headers hdr, inout metadata meta) {
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/*************************************************************************
|
||||
*********************** D E P A R S E R *******************************
|
||||
*************************************************************************/
|
||||
|
||||
control MyDeparser(packet_out packet, in headers hdr) {
|
||||
/* paketi aldigimiz gibi birakiyoruz :) */
|
||||
apply {
|
||||
/* TODO: add deparser logic */
|
||||
packet.emit(hdr.ethernet);
|
||||
packet.emit(hdr.ipv4);
|
||||
}
|
||||
}
|
||||
|
||||
/*************************************************************************
|
||||
*********************** S W I T C H *******************************
|
||||
*************************************************************************/
|
||||
|
||||
V1Switch(
|
||||
MyParser(),
|
||||
MyVerifyChecksum(),
|
||||
|
Loading…
x
Reference in New Issue
Block a user