> For the complete documentation index, see [llms.txt](https://anida-huang.gitbook.io/notes-network-simulation-and-analysis/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://anida-huang.gitbook.io/notes-network-simulation-and-analysis/qi-mo/20210524-static-routing.md). # 20210531 Programming Protocol-independent Packet Processors ( P4 ) - 4 ## 課堂資料 > 範例程式 ### Copy to CPU {% embed url="" %} {% embed url="" %} ### Send to CPU {% embed url="" %} ### Send to CPU2 {% embed url="" %} ### 課堂作業附件
{% embed url="" %} {% embed url="" %} ## 課堂練習 {% tabs %} {% tab title="Terminal 01" %} ``` cd Downloads ``` ``` mkdir copy-to-cpu send-to-cpu send-to-cpu2 ``` ``` mv -f copy-to-cpu.zip copy-to-cpu/ ``` ``` mv -f send_to_cpu.zip send-to-cpu/ ``` ``` mv -f send_to_cpu2.zip send-to-cpu2/ ``` ``` cd copy-to-cpu ``` ``` unzip copy-to-cpu.zip ``` ``` cd .. ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm1snqLcpAoO1-QC9U%2Fimage.png?alt=media\&token=1fe5b4e0-ddb5-4200-a245-91bfc5d72faf) ``` cd send-to-cpu ``` ``` unzip send_to_cpu.zip ``` ``` cd .. ``` ``` cd send-to-cpu2 ``` ``` unzip send_to_cpu2.zip ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm2Bz-Ejy5XRiXS3pe%2Fimage.png?alt=media\&token=84f39e3b-579b-41d3-b4df-8426f12c2c24) {% endtab %} {% endtabs %} ``` cd .. ``` ### Copy to CPU ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mb-IYTuyztXorfgeThk%2F-Mb0-53-1mO352YHR0Ha%2Fimage.png?alt=media\&token=6f080390-65f0-4bce-9b48-2333362a3ecc) {% tabs %} {% tab title="Terminal 01" %} ``` cd copy-to-cpu ``` ``` gedit p4app.json basic.p4 receive.py cmd.txt & ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm2UuOKtL5Ga11OVlV%2Fimage.png?alt=media\&token=5aa16ae8-775e-4024-898c-c1e9e6114302) ``` sed -i '/^$/d' p4app.json ``` ``` p4run ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm54iGLDiT5cfy6Rx2%2Fimage.png?alt=media\&token=62eec57b-3d69-4c13-8943-beb9e9316b3c) ``` s1 ifconfig ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm5KPDLh1tf1Zs_EA-%2Fimage.png?alt=media\&token=63a26a79-37ad-4053-b110-aa777ab2ce86) > **監聽後進行`h1 ping h2`** ``` h1 ping h2 -c 5 ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm6a5-nTAoA_zh9Nrg%2Fimage.png?alt=media\&token=c6064737-ba14-4fe9-b2b8-a16f8054f7c5) ``` xterm h2 h1 ``` {% endtab %} {% tab title="gedit" %} {% hint style="info" %} **p4app.json** ``` { "program": "basic.p4", "switch": "simple_switch", "compiler": "p4c", "options": "--target bmv2 --arch v1model --std p4-16", "switch_cli": "simple_switch_CLI", "cli": true, "pcap_dump": true, "enable_log": true, "topo_module": { "file_path": "", "module_name": "p4utils.mininetlib.apptopo", "object_name": "AppTopoStrategies" }, "controller_module": null, "topodb_module": { "file_path": "", "module_name": "p4utils.utils.topology", "object_name": "Topology" }, "mininet_module": { "file_path": "", "module_name": "p4utils.mininetlib.p4net", "object_name": "P4Mininet" }, "topology": { "assignment_strategy": "l2", "links": [["h1", "s1"], ["h2", "s1"]], "hosts": { "h1": { }, "h2": { } }, "switches": { "s1": { "cli_input": "cmd.txt", "program": "basic.p4", "cpu_port": true } } } } ``` **basic.p4** ``` /* -*- P4_16 -*- */ #include #include /************************************************************************* *********************** H E A D E R S *********************************** *************************************************************************/ struct metadata { /* empty */ } struct headers { } /************************************************************************* *********************** P A R S E R *********************************** *************************************************************************/ parser MyParser(packet_in packet, out headers hdr, inout metadata meta, inout standard_metadata_t standard_metadata) { state start { 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) { action drop() { mark_to_drop(standard_metadata); } action forward(bit<9> port) { standard_metadata.egress_spec = port; } table phy_forward { key = { standard_metadata.ingress_port: exact; } actions = { forward; drop; } size = 1024; default_action = drop(); } apply { phy_forward.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 { if (standard_metadata.instance_type == 0 ){ clone(CloneType.E2E,100); } } } /************************************************************************* ************* 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 { } } /************************************************************************* *********************** D E P A R S E R ******************************* *************************************************************************/ control MyDeparser(packet_out packet, in headers hdr) { apply { } } /************************************************************************* *********************** S W I T C H ******************************* *************************************************************************/ V1Switch( MyParser(), MyVerifyChecksum(), MyIngress(), MyEgress(), MyComputeChecksum(), MyDeparser() ) main; ``` **receive.py** ``` #!/usr/bin/env python import sys import struct import os from scapy.all import sniff, sendp, hexdump, get_if_list, get_if_hwaddr, bind_layers from scapy.all import Packet, IPOption, Ether from scapy.all import ShortField, IntField, LongField, BitField, FieldListField, FieldLenField from scapy.all import IP, UDP, Raw, ls from scapy.layers.inet import _IPOption_HDR class CpuHeader(Packet): name = 'CpuPacket' fields_desc = [BitField("device_id",0,16), BitField('reason',0,16), BitField('counter', 0, 80)] bind_layers(CpuHeader, Ether) def handle_pkt(pkt): print "Controller got a packet" print pkt.summary() def main(): if len(sys.argv) < 2: iface = 's1-cpu-eth1' else: iface = sys.argv[1] print "sniffing on %s" % iface sys.stdout.flush() sniff(iface = iface, prn = lambda x: handle_pkt(x)) if __name__ == '__main__': main() ``` **cmd.txt** ``` table_add phy_forward forward 1 => 2 table_add phy_forward forward 2 => 1 mirroring_add 100 3 ``` {% endhint %} {% endtab %} {% tab title="Terminal 02" %} ``` cd Downloads/copy-to-cpu ``` > **進行監聽** ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-Mbm6M00gzRW2g2hfvq_%2Fimage.png?alt=media\&token=6add7fc5-4d0a-49a6-b1d9-2678cf56f6ad) ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-MbmCho9veLX8QtEftOy%2Fimage.png?alt=media\&token=4cd36605-26de-4b58-944e-979270fd94d0) {% endtab %} {% tab title="h2" %} ``` python server.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-MbmCaFDVXq2JUPbKJef%2Fimage.png?alt=media\&token=cbecaf39-540d-4e3c-a8f5-844a64967b9e) {% endtab %} {% tab title="h1" %} ``` python client.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm-CVSlxcUl0D5Is83%2F-MbmCXAF7dG6Hn2p6SOz%2Fimage.png?alt=media\&token=e6f7c067-1089-4db2-a73f-362c13a38774) {% endtab %} {% tab title="Terminal 03" %} ``` cd Downloads/copy-to-cpu ``` ``` gedit client.py server.py ``` ``` rm -rf socket.pyc ``` {% endtab %} {% tab title="gedit 02" %} {% hint style="info" %} **server.py** ``` import socket import sys # Create a TCP/IP socket sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Bind the socket to the port server_address = ('10.0.0.2', 10000) print >>sys.stderr, 'starting up on %s port %s' % server_address sock.bind(server_address) # Listen for incoming connections sock.listen(1) connection, client_address = sock.accept() print >>sys.stderr, 'connection from', client_address data = connection.recv(1024) print >>sys.stderr, 'received "%s"' % data connection.close() ``` **client.py** ``` import socket import sys # Create a TCP/IP socket sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Connect the socket to the port where the server is listening server_address = ('10.0.0.2', 10000) print >>sys.stderr, 'connecting to %s port %s' % server_address sock.connect(server_address) # Send data message = 'hello world' print >>sys.stderr, 'sending "%s"' % message sock.sendall(message) sock.close() ``` {% endhint %} {% endtab %} {% endtabs %} ``` cd .. ``` ### Send to CPU ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mb-IYTuyztXorfgeThk%2F-Mb08JpL3fwtuK2uU5FU%2Fimage.png?alt=media\&token=e93b6345-2714-482a-bf9e-f827709d95d4) {% tabs %} {% tab title="Terminal 01" %} ``` cd send-to-cpu ``` ``` sed -i '/^$/d' p4app.json ``` ``` gedit p4app.json send_to_cpu.p4 s1-commands.txt s2-commands.txt s3-commands.txt controller.py & ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmFzt0kFbZSkIwVrhc%2Fimage.png?alt=media\&token=16ba7a31-f02f-4deb-be93-7a50df40f01e) ``` p4run ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmH_0KWfUn3Fx91TmQ%2Fimage.png?alt=media\&token=18ec2b83-c076-4f0e-9a57-a8cc74823110) ``` h1 ping h2 -c 5 ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmHs2jVYB332nH-HEJ%2Fimage.png?alt=media\&token=88c2fdc7-fdae-4eec-bb6f-d85899cd7152) {% endtab %} {% tab title="gedit" %} {% hint style="info" %} **p4app.json** ``` { "program": "send_to_cpu.p4", "switch": "simple_switch", "compiler": "p4c", "options": "--target bmv2 --arch v1model --std p4-16", "switch_cli": "simple_switch_CLI", "cli": true, "pcap_dump": true, "enable_log": true, "cpu_port": true, "topo_module": { "file_path": "", "module_name": "p4utils.mininetlib.apptopo", "object_name": "AppTopo" }, "controller_module": null, "topodb_module": { "file_path": "", "module_name": "p4utils.utils.topology", "object_name": "Topology" }, "mininet_module": { "file_path": "", "module_name": "p4utils.mininetlib.p4net", "object_name": "P4Mininet" }, "topology": { "links": [["h1","s1"], ["s3","h2"], ["s1","s2"], ["s2","s3"]], "hosts": { "h1": { }, "h2": { } }, "switches": { "s1": { "cli_input": "s1-commands.txt", "program": "send_to_cpu.p4", "cpu_port": true }, "s2": { "cli_input": "s2-commands.txt", "program": "send_to_cpu.p4", "cpu_port": true }, "s3": { "cli_input": "s3-commands.txt", "program": "send_to_cpu.p4", "cpu_port": true } } } } ``` **send\_to\_cpu.p4** ``` /* -*- P4_16 -*- */ #include #include 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; header ethernet_t { macAddr_t dstAddr; macAddr_t srcAddr; bit<16> etherType; } header ipv4_t { bit<4> version; bit<4> ihl; bit<8> tos; bit<16> totalLen; bit<16> identification; bit<3> flags; bit<13> fragOffset; bit<8> ttl; bit<8> protocol; bit<16> hdrChecksum; ip4Addr_t srcAddr; ip4Addr_t dstAddr; } struct metadata { } struct headers { ethernet_t ethernet; 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) { state start { packet.extract(hdr.ethernet); transition select(hdr.ethernet.etherType){ TYPE_IPV4: ipv4; default: accept; } } state 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) { action drop() { mark_to_drop(standard_metadata); } action ipv4_forward(macAddr_t dstAddr, egressSpec_t port) { //set the src mac address as the previous dst, this is not correct right? hdr.ethernet.srcAddr = hdr.ethernet.dstAddr; //set the destination mac address that we got from the match in the table hdr.ethernet.dstAddr = dstAddr; //set the output port that we also get from the table standard_metadata.egress_spec = port; //decrease ttl by 1 hdr.ipv4.ttl = hdr.ipv4.ttl -1; } table ipv4_lpm { key = { hdr.ipv4.dstAddr: lpm; } actions = { ipv4_forward; drop; NoAction; } size = 1024; default_action = NoAction(); } apply { //only if IPV4 the rule is applied. Therefore other packets will not be forwarded. 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 { if (standard_metadata.instance_type == 0 ){ clone3(CloneType.E2E,100, meta); } //handle the cloned packet if (standard_metadata.instance_type != 0){ truncate((bit<32>)34); //ether+ip header } } } /************************************************************************* ************* 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( hdr.ipv4.isValid(), { hdr.ipv4.version, hdr.ipv4.ihl, hdr.ipv4.tos, hdr.ipv4.totalLen, hdr.ipv4.identification, hdr.ipv4.flags, hdr.ipv4.fragOffset, hdr.ipv4.ttl, hdr.ipv4.protocol, hdr.ipv4.srcAddr, hdr.ipv4.dstAddr }, hdr.ipv4.hdrChecksum, HashAlgorithm.csum16); } } /************************************************************************* *********************** D E P A R S E R ******************************* *************************************************************************/ control MyDeparser(packet_out packet, in headers hdr) { apply { //parsed headers have to be added again into the packet. packet.emit(hdr.ethernet); packet.emit(hdr.ipv4); } } /************************************************************************* *********************** S W I T C H ******************************* *************************************************************************/ //switch architecture V1Switch( MyParser(), MyVerifyChecksum(), MyIngress(), MyEgress(), MyComputeChecksum(), MyDeparser() ) main; ``` **s1-commands.txt** ``` table_set_default ipv4_lpm drop table_add MyIngress.ipv4_lpm ipv4_forward 10.0.1.0/24 => 00:00:0a:00:01:01 1 table_add MyIngress.ipv4_lpm ipv4_forward 10.0.3.0/24 => 00:00:00:02:01:00 2 //creates a mirroring ID 100 to output port 3 mirroring_add 100 3 ``` **s2-commands.txt** ``` table_set_default ipv4_lpm drop table_add MyIngress.ipv4_lpm ipv4_forward 10.0.1.0/24 => 00:00:00:01:01:00 1 table_add MyIngress.ipv4_lpm ipv4_forward 10.0.3.0/24 => 00:00:00:03:01:00 2 //creates a mirroring ID 100 to output port 3 //mirroring_add 100 3 ``` **s3-commands.txt** ``` table_set_default ipv4_lpm drop table_add MyIngress.ipv4_lpm ipv4_forward 10.0.1.0/24 => 00:00:00:02:01:00 2 table_add MyIngress.ipv4_lpm ipv4_forward 10.0.3.2/32 => 00:00:0a:00:03:02 1 //creates a mirroring ID 100 to output port 3 mirroring_add 100 3 ``` **controller.py** ``` import nnpy import struct from p4utils.utils.topology import Topology from p4utils.utils.sswitch_API import SimpleSwitchAPI from scapy.all import Ether, sniff, Packet, BitField class myController(object): def __init__(self): self.topo = Topology(db="topology.db") self.controllers = {} self.connect_to_switches() def connect_to_switches(self): for p4switch in self.topo.get_p4switches(): thrift_port = self.topo.get_thrift_port(p4switch) #print "p4switch:", p4switch, "thrift_port:", thrift_port self.controllers[p4switch] = SimpleSwitchAPI(thrift_port) def recv_msg_cpu(self, pkt): print "interface:", pkt.sniffed_on print "summary:", pkt.summary() def run_cpu_port_loop(self): cpu_interfaces = [str(self.topo.get_cpu_port_intf(sw_name).replace("eth0", "eth1")) for sw_name in self.controllers] sniff(iface=cpu_interfaces, prn=self.recv_msg_cpu) if __name__ == "__main__": controller = myController() controller.run_cpu_port_loop() ``` {% endhint %} {% endtab %} {% tab title="Terminal 02" %} ``` cd send-to-cpu ``` ``` python controller.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmI13EWR_jRBHP_yN8%2Fimage.png?alt=media\&token=e28393e1-57c3-4f23-b609-9d78d6432872) {% endtab %} {% endtabs %} ``` cd .. ``` ### Send to CPU2 {% tabs %} {% tab title="Terminal 01" %} ``` cd send-to-cpu2 ``` ``` sed -i '/^$/d' p4app.json ``` ``` gedit p4app.json send_to_cpu.p4 s1-commands.txt s2-commands.txt s3-commands.txt controller.py & ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmIteLdQX0TQzx3pL-%2Fimage.png?alt=media\&token=54f355e0-bb91-4d3c-917a-54925b0307bb) ``` p4run ``` ``` xterm h1 h2 ``` {% endtab %} {% tab title="gedit" %} {% hint style="info" %} **p4app.json** ``` { "program": "send_to_cpu.p4", "switch": "simple_switch", "compiler": "p4c", "options": "--target bmv2 --arch v1model --std p4-16", "switch_cli": "simple_switch_CLI", "cli": true, "pcap_dump": true, "enable_log": true, "cpu_port": true, "topo_module": { "file_path": "", "module_name": "p4utils.mininetlib.apptopo", "object_name": "AppTopo" }, "controller_module": null, "topodb_module": { "file_path": "", "module_name": "p4utils.utils.topology", "object_name": "Topology" }, "mininet_module": { "file_path": "", "module_name": "p4utils.mininetlib.p4net", "object_name": "P4Mininet" }, "topology": { "links": [["h1","s1"], ["s3","h2"], ["s1","s2"], ["s2","s3"]], "hosts": { "h1": { }, "h2": { } }, "switches": { "s1": { "cli_input": "s1-commands.txt", "program": "send_to_cpu.p4", "cpu_port": true }, "s2": { "cli_input": "s2-commands.txt", "program": "send_to_cpu.p4", "cpu_port": true }, "s3": { "cli_input": "s3-commands.txt", "program": "send_to_cpu.p4", "cpu_port": true } } } } ``` **send\_to\_cpu.p4** ``` /* -*- P4_16 -*- */ #include #include 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; header ethernet_t { macAddr_t dstAddr; macAddr_t srcAddr; bit<16> etherType; } header ipv4_t { bit<4> version; bit<4> ihl; bit<8> tos; bit<16> totalLen; bit<16> identification; bit<3> flags; bit<13> fragOffset; bit<8> ttl; bit<8> protocol; bit<16> hdrChecksum; ip4Addr_t srcAddr; ip4Addr_t dstAddr; } struct metadata { } struct headers { ethernet_t ethernet; 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) { state start { packet.extract(hdr.ethernet); transition select(hdr.ethernet.etherType){ TYPE_IPV4: ipv4; default: accept; } } state 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) { action drop() { mark_to_drop(standard_metadata); } action ipv4_forward(macAddr_t dstAddr, egressSpec_t port) { //set the src mac address as the previous dst, this is not correct right? hdr.ethernet.srcAddr = hdr.ethernet.dstAddr; //set the destination mac address that we got from the match in the table hdr.ethernet.dstAddr = dstAddr; //set the output port that we also get from the table standard_metadata.egress_spec = port; //decrease ttl by 1 hdr.ipv4.ttl = hdr.ipv4.ttl -1; } action to_cpu(egressSpec_t port) { standard_metadata.egress_spec = port; } table ipv4_lpm { key = { hdr.ipv4.dstAddr: lpm; } actions = { ipv4_forward; to_cpu; drop; } size = 1024; } apply { //only if IPV4 the rule is applied. Therefore other packets will not be forwarded. 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( hdr.ipv4.isValid(), { hdr.ipv4.version, hdr.ipv4.ihl, hdr.ipv4.tos, hdr.ipv4.totalLen, hdr.ipv4.identification, hdr.ipv4.flags, hdr.ipv4.fragOffset, hdr.ipv4.ttl, hdr.ipv4.protocol, hdr.ipv4.srcAddr, hdr.ipv4.dstAddr }, hdr.ipv4.hdrChecksum, HashAlgorithm.csum16); } } /************************************************************************* *********************** D E P A R S E R ******************************* *************************************************************************/ control MyDeparser(packet_out packet, in headers hdr) { apply { //parsed headers have to be added again into the packet. packet.emit(hdr.ethernet); packet.emit(hdr.ipv4); } } /************************************************************************* *********************** S W I T C H ******************************* *************************************************************************/ //switch architecture V1Switch( MyParser(), MyVerifyChecksum(), MyIngress(), MyEgress(), MyComputeChecksum(), MyDeparser() ) main; ``` **s1-commands.txt** ``` table_set_default ipv4_lpm to_cpu 3 ``` **s2-commands.txt** ``` ``` **s3-commands.txt** ``` table_set_default ipv4_lpm to_cpu 3 ``` **controller.py** ``` import nnpy import struct from p4utils.utils.topology import Topology from p4utils.utils.sswitch_API import SimpleSwitchAPI #from scapy.all import Ether, sniff, Packet, BitField from scapy.all import * rules=[] class myController(object): def __init__(self): self.topo = Topology(db="topology.db") self.controllers = {} self.connect_to_switches() def connect_to_switches(self): for p4switch in self.topo.get_p4switches(): thrift_port = self.topo.get_thrift_port(p4switch) #print "p4switch:", p4switch, "thrift_port:", thrift_port self.controllers[p4switch] = SimpleSwitchAPI(thrift_port) def recv_msg_cpu(self, pkt): print "-------------------------------------------------------------------" global rules print "interface:", pkt.sniffed_on print "summary:", pkt.summary() if IP in pkt: ip_src=pkt[IP].src ip_dst=pkt[IP].dst print "ip_src:", ip_src, " ip_dst:", ip_dst if (ip_src, ip_dst) not in rules: rules.append((ip_src, ip_dst)) print "rules:", rules else: return switches = {sw_name:{} for sw_name in self.topo.get_p4switches().keys()} #print "switches:", switches for sw_name, controller in self.controllers.items(): for host in self.topo.get_hosts_connected_to(sw_name): host_ip_addr = self.topo.get_host_ip(host) if ip_src == host_ip_addr: sw_src = sw_name if ip_dst == host_ip_addr: sw_dst = sw_name sw_port = self.topo.node_to_node_port_num(sw_name, host) host_ip = self.topo.get_host_ip(host) + "/32" host_mac = self.topo.get_host_mac(host) #print host, "(", host_ip, host_mac, ")", "-->", sw_name, "with port:", sw_port #add rule print "table_add at {}:".format(sw_name) self.controllers[sw_name].table_add("ipv4_lpm", "ipv4_forward", [str(host_ip)], [str(host_mac), str(sw_port)]) print "sw_src:", sw_src, "sw_dst:", sw_dst paths = self.topo.get_shortest_paths_between_nodes(sw_src, sw_dst) sw_1=sw_src for next_hop in paths[0][1:]: host_ip = ip_dst + "/32" sw_port = self.topo.node_to_node_port_num(sw_1, next_hop) dst_sw_mac = self.topo.node_to_node_mac(next_hop, sw_1) #add rule print "table_add at {}:".format(sw_1) self.controllers[sw_1].table_add("ipv4_lpm", "ipv4_forward", [str(host_ip)], [str(dst_sw_mac), str(sw_port)]) sw_1=next_hop print "send original packet back from ", pkt.sniffed_on sendp(pkt, iface=pkt.sniffed_on, verbose=False) def run_cpu_port_loop(self): cpu_interfaces = [str(self.topo.get_cpu_port_intf(sw_name).replace("eth0", "eth1")) for sw_name in self.controllers] sniff(iface=cpu_interfaces, prn=self.recv_msg_cpu) if __name__ == "__main__": controller = myController() controller.run_cpu_port_loop() ``` {% endhint %} {% endtab %} {% tab title="Terminal 02" %} ``` cd send-to-cpu2 ``` ``` simple_switch_CLI --thrift-port 9090 ``` ``` table_dump ipv4_lpm ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmLlfIvX5FvQMcj_14%2Fimage.png?alt=media\&token=b447c51d-0a03-4ce5-b833-a9a111d703be) ``` simple_switch_CLI --thrift-port 9091 ``` ``` table_dump ipv4_lpm ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmLutkMSk2Ym5VJE3P%2Fimage.png?alt=media\&token=648e1ae9-e5cb-4f28-8981-362babbd5e57) ``` simple_switch_CLI --thrift-port 9092 ``` ``` table_dump ipv4_lpm ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmM4uoFvDG8NKz0V2B%2Fimage.png?alt=media\&token=aea1b74a-5de9-4081-9b90-453f33c48ebc) ``` python controller.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmMrHY27aIFl1DLcCE%2Fimage.png?alt=media\&token=71a7daf3-6c87-4789-9743-0a536db29767) {% endtab %} {% tab title="h1" %} ``` ping 10.0.3.2 -c 5 ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmCqMWjSct2oiWj6ao%2F-MbmMws_S03q6WSVI9Ks%2Fimage.png?alt=media\&token=9b26d41a-8122-4021-85eb-66a03edece99) {% endtab %} {% tab title="h2" %} ``` ``` {% endtab %} {% endtabs %} ### Broadcast / Multicast ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mb0MxqYY76gcefXD-9O%2F-Mb0WySu6kxulW2xUprh%2Fimage.png?alt=media\&token=22e02c82-71af-49d4-b6a3-5bf6ed09ca76) {% tabs %} {% tab title="Terminal 01" %} ``` cd p4-test/test-broadcast ``` ``` p4run ``` ``` xterm h1 h2 h3 ``` {% endtab %} {% tab title="h2" %} > **接收`h1`傳送** ``` python receive.py ``` > **進行傳送，由`h1`、`h3`接收** ``` python send.py ``` > **接收`h3`傳送** ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmUlT-fCGibuniCVlM%2F-MbmXdWtN2jqW3ZZ9LHX%2Fimage.png?alt=media\&token=cd1c6ce8-1723-4af4-83d4-16c4a836b1ef) {% endtab %} {% tab title="h3" %} > **接收`h1`傳送** ``` python receive.py ``` > **接收`h2`傳送** ``` python receive.py ``` > **進行傳送，由`h1`、`h2`接收** ``` python send.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmUlT-fCGibuniCVlM%2F-MbmXYVeOrJg6Or-fTDN%2Fimage.png?alt=media\&token=3fdfcc2e-0d4f-4844-ac1f-aa97a0291a78) {% endtab %} {% tab title="h1" %} > **進行傳送，由`h2`、`h3`接收** ``` python send.py ``` > **接收`h2`傳送** ``` python receive.py ``` > **接收`h3`傳送** ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-MbmUlT-fCGibuniCVlM%2F-MbmXSbH1Lk7va-QcSb_%2Fimage.png?alt=media\&token=264735a1-3f4a-4d6a-a810-091fddfe56dd) {% endtab %} {% endtabs %} #### 延伸 ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mb-IYTuyztXorfgeThk%2F-Mb0MKN7yPqy_uNxRXnw%2Fimage.png?alt=media\&token=15303fac-381a-4e5e-9721-eca036d1aa10) * **`Broadcast`**：當接收封包時，廣播至所有節點 * **`Multicast`**：針對有興趣的節點傳送封包 ## 課堂作業 ### Multicast ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mb0MxqYY76gcefXD-9O%2F-Mb0X-KlJRQ4peVYhXAI%2Fimage.png?alt=media\&token=b343f677-5d22-4bec-843a-a4cdba51a606) {% tabs %} {% tab title="Terminal 01" %} ``` cd p4-test ``` ``` cp -r test-broadcast/ multicast ``` ``` cd multicast ``` ``` gedit basic.p4 p4app.json cmd.txt ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmbTG1HGjkdmj2tlns%2Fimage.png?alt=media\&token=1cf248df-4125-4862-ad72-a0737df85b30) ``` gedit send.py receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-Mbmbvz5Pzq2ogROekKi%2Fimage.png?alt=media\&token=1dfaacfa-951f-49d7-9977-e6ad1803b3b5) ``` p4run ``` ``` xterm h1 h2 h3 h4 ``` {% endtab %} {% tab title="gedit" %} {% hint style="info" %} **p4app.json** ``` { "program": "basic.p4", "switch": "simple_switch", "compiler": "p4c", "options": "--target bmv2 --arch v1model --std p4-16", "switch_cli": "simple_switch_CLI", "cli": true, "pcap_dump": false, "enable_log": true, "topo_module": { "file_path": "", "module_name": "p4utils.mininetlib.apptopo", "object_name": "AppTopoStrategies" }, "controller_module": null, "topodb_module": { "file_path": "", "module_name": "p4utils.utils.topology", "object_name": "Topology" }, "mininet_module": { "file_path": "", "module_name": "p4utils.mininetlib.p4net", "object_name": "P4Mininet" }, "topology": { "links": [["h1", "s1"], ["h2", "s1"], ["h3", "s1"], ["h4", "s1"]], "hosts": { "h1": { }, "h2": { }, "h3": { }, "h4": { } }, "switches": { "s1": { "cli_input": "cmd.txt", "program": "basic.p4" } } } } ``` **basic.p4** ``` /* -*- P4_16 -*- */ #include #include /************************************************************************* *********************** H E A D E R S *********************************** *************************************************************************/ header ethernet_t { bit<48> dstAddr; bit<48> srcAddr; bit<16> etherType; } header ipv4_t { bit<4> version; bit<4> ihl; bit<8> diffserv; bit<16> totalLen; bit<16> identification; bit<3> flags; bit<13> fragOffset; bit<8> ttl; bit<8> protocol; bit<16> hdrChecksum; bit<32> srcAddr; bit<32> dstAddr; } struct metadata { /* empty */ } struct headers { ethernet_t ethernet; 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) { state parse_ethernet { packet.extract(hdr.ethernet); transition select(hdr.ethernet.etherType) { 16w0x800: parse_ipv4; default: accept; } } state parse_ipv4 { packet.extract(hdr.ipv4); transition accept; } state start { transition parse_ethernet; } } /************************************************************************* ************ 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) { action drop() { mark_to_drop(standard_metadata); } action forward(bit<9> port) { standard_metadata.egress_spec = port; } table mac_forward { key = { hdr.ethernet.dstAddr: exact; } actions = { forward; drop; } size = 1024; default_action = drop(); } action broadcast(bit<16> mcast_grp_id) { standard_metadata.mcast_grp = mcast_grp_id; } table ip_broadcast { key = { hdr.ipv4.dstAddr: exact; standard_metadata.ingress_port: exact; } actions = { broadcast; NoAction; } size = 1024; default_action = NoAction(); } apply { if (!ip_broadcast.apply().hit){ mac_forward.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 { } } /************************************************************************* *********************** D E P A R S E R ******************************* *************************************************************************/ control MyDeparser(packet_out packet, in headers hdr) { apply { packet.emit(hdr.ethernet); packet.emit(hdr.ipv4); } } /************************************************************************* *********************** S W I T C H ******************************* *************************************************************************/ V1Switch( MyParser(), MyVerifyChecksum(), MyIngress(), MyEgress(), MyComputeChecksum(), MyDeparser() ) main; ``` **cmd.txt** ``` table_add mac_forward forward 00:00:0a:00:01:01 => 1 table_add mac_forward forward 00:00:0a:00:01:02 => 2 table_add mac_forward forward 00:00:0a:00:01:03 => 3 table_add ip_broadcast broadcast 224.0.0.10 1 => 1 mc_mgrp_create 1 mc_node_create 0 2 4 mc_node_associate 1 0 ``` **send.py** ``` #!/usr/bin/env python from socket import * s = socket(AF_INET, SOCK_DGRAM) s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) s.sendto('hello everyone', ('224.0.0.10', 1234)) ``` **receive.py** ``` import socket import struct MCAST_GRP = '224.0.0.10' MCAST_PORT = 1234 IS_ALL_GROUPS = True sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) if IS_ALL_GROUPS: # on this port, receives ALL multicast groups sock.bind(('', MCAST_PORT)) else: # on this port, listen ONLY to MCAST_GRP sock.bind((MCAST_GRP, MCAST_PORT)) mreq = struct.pack("4sl", socket.inet_aton(MCAST_GRP), socket.INADDR_ANY) sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq) while True: # For Python 3, change next line to "print(sock.recv(10240))" print sock.recv(10240) ``` {% endhint %} {% endtab %} {% tab title="h4" %} ``` wireshark ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmePz52zalgaYEVX_Z%2Fimage.png?alt=media\&token=60f67f29-69af-417c-9c68-e90b3b05a609) ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmfgXs9gPsxipruWyV%2Fimage.png?alt=media\&token=bf8a6925-8702-468d-8957-b28e2c0c0cdf) {% endtab %} {% tab title="h3" %} ``` wireshark ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmeXFrIjRzkz2BwH-C%2Fimage.png?alt=media\&token=cfe824cc-1e29-41e3-8cb9-14daf09c674f) ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmflANeyxvFI9dn42L%2Fimage.png?alt=media\&token=fcc5775f-d650-4fb2-9745-ef01d80d83bc) {% endtab %} {% tab title="h2" %} ``` wireshark ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmebVQE8zBGWe2Ie9f%2Fimage.png?alt=media\&token=3e9168d8-b6a3-46e3-b2b6-111cee26be75) ``` python receive.py ``` ![](https://1624492921-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MU7EdDCmxVnXY6VZf4s%2F-Mbm_dF3hIV1mpaGzhsB%2F-MbmfOyGsyOYUYBnXzja%2Fimage.png?alt=media\&token=eb4513d9-3b77-4349-a82a-33a2e072eb6a) {% endtab %} {% tab title="h1" %} > **進行傳送，由`h2`、`h3`、`h4`進行`wireshark`監測** ``` python send.py ``` > **再次傳送，由`h2`、`h3`、`h4`進行監測** ``` python send.py ``` {% endtab %} {% endtabs %}