VM Updates (#83)

- Minor fixes to p4runtime exercise and README
- Adding p4runtime/solution
- Adding p4runtime/topology.json
- Updating .gitignore to include solution directory and topology.json
- Fixing root-bootstrap to exit on errors
- Updating VM name in Vagrantfile
- Setting up VM to automatically log 'p4' user in on startup
This commit is contained in:
Brian O'Connor 2017-11-08 08:13:17 -08:00 committed by Robert Soule
parent 9af6750bec
commit b2161b8a27
7 changed files with 334 additions and 53 deletions

2
.gitignore vendored
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@ -8,11 +8,13 @@
# Compiled JSON
*.json
!*p4app.json
!topology.json
*.pcap
# Extracted solutions
solution*/
!solution/
# Build folders
build*/

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@ -3,11 +3,11 @@
## Introduction
In this exercise, we will be using P4 Runtime to send flow entries to the
switch, instead of using the switch's CLI. We will be using the same P4
program that you used in the previous in the basic_tunnel exercise. The
switch instead of using the switch's CLI. We will be building on the same P4
program that you used in the [basic_tunnel](../basic_tunnel) exercise. The
P4 program has be renamed to `advanced_tunnel.py` and has been augmented
with a counter, `tunnelCount`, and two new actions, `myTunnel_ingress`
and `myTunnel_egress`.
with two counters (`ingressTunnelCounter`, `egressTunnelCounter`) and
two new actions (`myTunnel_ingress`, `myTunnel_egress`).
You will use the starter program, `mycontroller.py`, and a few helper
libraries in the `p4runtime_lib` directory to create the table entries
@ -19,12 +19,12 @@ necessary to tunnel traffic between host 1 and 2.
## Step 1: Run the (incomplete) starter code
The starter code for this assignment is in a file called `mycontroller.py`
The starter code for this assignment is in a file called `mycontroller.py`,
and it will install only some of the rules that you need tunnel traffic between
two hosts.
Let's first compile the new P4 program, start the network, use `mycontroller.py`
to install a few rules, and look at the tunnel ingress counter to see that things
to install a few rules, and look at the `ingressTunnelCounter` to see that things
are working as expected.
1. In your shell, run:
@ -32,18 +32,17 @@ are working as expected.
make
```
This will:
* compile `advanced_tunnel.p4`, and
* compile `advanced_tunnel.p4`,
* start a Mininet instance with three switches (`s1`, `s2`, `s3`)
configured in a triangle, each connected to one host (`h1`, `h2`,
and `h3`).
* The hosts are assigned IPs of `10.0.1.1`, `10.0.2.2`, etc.
configured in a triangle, each connected to one host (`h1`, `h2`, `h3`), and
* assign IPs of `10.0.1.1`, `10.0.2.2`, `10.0.3.3` to the respective hosts.
2. You should now see a Mininet command prompt. Start a ping between h1 and h2:
```bash
mininet> h1 ping h2
```
Because there are no rules on the switches, you should **not** receive any
replies yet.
replies yet. You should leave the ping running in this shell.
3. Open another shell and run the starter code:
```bash
@ -65,6 +64,25 @@ Each switch is currently mapping traffic into tunnels based on the destination I
address. Your job is to write the rules that forward the traffic between the switches
based on the tunnel ID.
### Potential Issues
If you see the following error message when running `mycontroller.py`, then
the gRPC server is not running on one or more switches.
```
p4@p4:~/tutorials/P4D2_2017_Fall/exercises/p4runtime$ ./mycontroller.py
...
grpc._channel._Rendezvous: <_Rendezvous of RPC that terminated with (StatusCode.UNAVAILABLE, Connect Failed)>
```
You can check to see which of gRPC ports are listening on the machine by running:
```bash
sudo netstat -lpnt
```
The easiest solution is to enter `Ctrl-D` or `exit` in the `mininet>` prompt,
and re-run `make`.
### A note about the control plane
A P4 program defines a packet-processing pipeline, but the rules
@ -96,6 +114,26 @@ that will match on tunnel ID and forward packets to the next hop.
![topology](../basic_tunnel/topo.png)
In this exercise, you will be interacting with some of the classes and methods in
the `p4runtime_lib` directory. Here is a summary of each of the files in the directory:
- `helper.py`
- Contains the `P4InfoHelper` class which is used to parse the `p4info` files.
- Provides translation methods from entity name to and from ID number.
- Builds P4 program-dependendent sections of P4 Runtime table entries.
- `switch.py`
- Contains the `SwitchConnection` class which grabs the gRPC client stub, and
establishes connections to the switches.
- Provides helper methods that construct the P4 Runtime protocol buffer messages
and makes the P4 Runtime gRPC service calls.
- `bmv2.py`
- Contains `Bmv2SwitchConnection` which extends `SwitchConnections` and provides
the BMv2-specific device payload to load the P4 program.
- `convert.py`
- Provides convenience methods to encode and decode from friendly strings and
numbers to the byte strings required for the protocol buffer messages.
- Used by `helper.py`
## Step 3: Run your solution
Follow the instructions from Step 1. If your Mininet network is still running,
@ -122,6 +160,10 @@ need to change it for a more realistic network?
- What is the TTL in the ICMP replies? Why is it the value that it is?
Hint: The default TTL is 64 for packets sent by the hosts.
If you are interested, you can find the protocol buffer and gRPC definitions here:
- [P4 Runtime](https://github.com/p4lang/PI/blob/master/proto/p4/p4runtime.proto)
- [P4 Info](https://github.com/p4lang/PI/blob/master/proto/p4/config/p4info.proto)
#### Cleaning up Mininet
If the Mininet shell crashes, it may leave a Mininet instance

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@ -9,62 +9,69 @@ import p4runtime_lib.helper
SWITCH_TO_HOST_PORT = 1
SWITCH_TO_SWITCH_PORT = 2
def writeTunnelRules(p4info_helper, ingressSw, egressSw, tunnelId, dstEthAddr, dstIpAddr):
def writeTunnelRules(p4info_helper, ingress_sw, egress_sw, tunnel_id,
dst_eth_addr, dst_ip_addr):
'''
Installs three rules:
1) An tunnel ingress rule on the ingress switch in the ipv4_lpm table that encapsulates traffic
into a tunnel with the specified ID
2) A transit rule on the ingress switch that forwards traffic based on the specified ID
3) An tunnel egress rule on the egress switch that decapsulates traffic with the specified ID
and sends it to the host
1) An tunnel ingress rule on the ingress switch in the ipv4_lpm table that
encapsulates traffic into a tunnel with the specified ID
2) A transit rule on the ingress switch that forwards traffic based on
the specified ID
3) An tunnel egress rule on the egress switch that decapsulates traffic
with the specified ID and sends it to the host
:param p4info_helper: the P4Info helper
:param ingressSw: the ingress switch connection
:param egressSw: the egress switch connection
:param tunnelId: the specified tunnel ID
:param dstEthAddr: the destination IP to match in the ingress rule
:param dstIpAddr: the destination Ethernet address to write in the egress rule
:param ingress_sw: the ingress switch connection
:param egress_sw: the egress switch connection
:param tunnel_id: the specified tunnel ID
:param dst_eth_addr: the destination IP to match in the ingress rule
:param dst_ip_addr: the destination Ethernet address to write in the
egress rule
'''
# 1) Tunnel Ingress Rule
table_entry = p4info_helper.buildTableEntry(
table_name="ipv4_lpm",
match_fields={
"hdr.ipv4.dstAddr": (dstIpAddr, 32)
"hdr.ipv4.dstAddr": (dst_ip_addr, 32)
},
action_name="myTunnel_ingress",
action_params={
"dst_id": tunnelId,
"dst_id": tunnel_id,
})
ingressSw.WriteTableEntry(table_entry)
print "Installed ingress tunnel rule on %s" % ingressSw.name
ingress_sw.WriteTableEntry(table_entry)
print "Installed ingress tunnel rule on %s" % ingress_sw.name
# 2) Tunnel Transit Rule
# TODO you will need to implement this rule
# The rule will need to be added to the myTunnel_exact table and match on the tunnel ID (hdr.myTunnel.dst_id).
# For our simple topology, transit traffic will need to be forwarded using the myTunnel_egress action to
# the SWITCH_TO_SWITCH_PORT (port 2).
# We will only need on transit rule on the ingress switch because we are using a simple topology.
# In general, you'll need on transit rule for each switch in the path (except the last one)
# The rule will need to be added to the myTunnel_exact table and match on
# the tunnel ID (hdr.myTunnel.dst_id). For our simple topology, transit
# traffic will need to be forwarded on the using the myTunnel_forward action
# on the SWITCH_TO_SWITCH_PORT (port 2).
#
# If you are stuck, start by copying the tunnel ingress rule from above. Then, try to make the suggested
# modifications.
# We will only need on transit rule on the ingress switch because we are
# using a simple topology. In general, you'll need on transit rule for
# each switch in the path (except the last one).
# TODO build the transit rule
# TODO install the transit rule on the ingress switch
print "TODO Install transit tunnel rule"
# 3) Tunnel Egress Rule
# For our simple topology, the host will always be located on the SWITCH_TO_HOST_PORT (port 1).
# In general, you will need to keep track of which port the host is connected to.
# For our simple topology, the host will always be located on the
# SWITCH_TO_HOST_PORT (port 1).
# In general, you will need to keep track of which port the host is
# connected to.
table_entry = p4info_helper.buildTableEntry(
table_name="myTunnel_exact",
match_fields={
"hdr.myTunnel.dst_id": tunnelId
"hdr.myTunnel.dst_id": tunnel_id
},
action_name="myTunnel_egress",
action_params={
"dstAddr": dstEthAddr,
"dstAddr": dst_eth_addr,
"port": SWITCH_TO_HOST_PORT
})
egressSw.WriteTableEntry(table_entry)
print "Installed egress tunnel rule on %s" % egressSw.name
egress_sw.WriteTableEntry(table_entry)
print "Installed egress tunnel rule on %s" % egress_sw.name
def readTableRules(p4info_helper, sw):
'''
@ -77,14 +84,16 @@ def readTableRules(p4info_helper, sw):
for response in sw.ReadTableEntries():
for entity in response.entities:
entry = entity.table_entry
# TODO For extra credit, you can use the p4info_helper to translate the IDs the entry to names
# TODO For extra credit, you can use the p4info_helper to translate
# the IDs the entry to names
print entry
print '-----'
def printCounter(p4info_helper, sw, counter_name, index):
'''
Reads the specified counter at the specified index from the switch. In our program, the index
is the tunnel ID. If the index is 0, it will return all values from the counter.
Reads the specified counter at the specified index from the switch. In our
program, the index is the tunnel ID. If the index is 0, it will return all
values from the counter.
:param p4info_helper: the P4Info helper
:param sw: the switch connection
@ -104,23 +113,26 @@ def main(p4info_file_path, bmv2_file_path):
# Instantiate a P4 Runtime helper from the p4info file
p4info_helper = p4runtime_lib.helper.P4InfoHelper(p4info_file_path)
# Create a switch connection object for s1 and s2; this is backed by a P4 Runtime gRPC connection
# Create a switch connection object for s1 and s2;
# this is backed by a P4 Runtime gRPC connection
s1 = p4runtime_lib.bmv2.Bmv2SwitchConnection('s1', address='127.0.0.1:50051')
s2 = p4runtime_lib.bmv2.Bmv2SwitchConnection('s2', address='127.0.0.1:50052')
# Install the P4 program on the switches
s1.SetForwardingPipelineConfig(p4info=p4info_helper.p4info, bmv2_json_file_path=bmv2_file_path)
s1.SetForwardingPipelineConfig(p4info=p4info_helper.p4info,
bmv2_json_file_path=bmv2_file_path)
print "Installed P4 Program using SetForwardingPipelineConfig on %s" % s1.name
s2.SetForwardingPipelineConfig(p4info=p4info_helper.p4info, bmv2_json_file_path=bmv2_file_path)
s2.SetForwardingPipelineConfig(p4info=p4info_helper.p4info,
bmv2_json_file_path=bmv2_file_path)
print "Installed P4 Program using SetForwardingPipelineConfig on %s" % s2.name
# Write the rules that tunnel traffic from h1 to h2
writeTunnelRules(p4info_helper, ingressSw=s1, egressSw=s2, tunnelId=100,
dstEthAddr="00:00:00:00:02:02", dstIpAddr="10.0.2.2")
writeTunnelRules(p4info_helper, ingress_sw=s1, egress_sw=s2, tunnel_id=100,
dst_eth_addr="00:00:00:00:02:02", dst_ip_addr="10.0.2.2")
# Write the rules that tunnel traffic from h2 to h1
writeTunnelRules(p4info_helper, ingressSw=s2, egressSw=s1, tunnelId=200,
dstEthAddr="00:00:00:00:01:01", dstIpAddr="10.0.1.1")
writeTunnelRules(p4info_helper, ingress_sw=s2, egress_sw=s1, tunnel_id=200,
dst_eth_addr="00:00:00:00:01:01", dst_ip_addr="10.0.1.1")
# TODO Uncomment the following two lines to read table entries from s1 and s2
#readTableRules(p4info_helper, s1)
@ -142,9 +154,11 @@ def main(p4info_file_path, bmv2_file_path):
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='P4Runtime Controller')
parser.add_argument('--p4info', help='p4info proto in text format from p4c',
type=str, action="store", required=False, default='./build/advanced_tunnel.p4info')
type=str, action="store", required=False,
default='./build/advanced_tunnel.p4info')
parser.add_argument('--bmv2-json', help='BMv2 JSON file from p4c',
type=str, action="store", required=False, default='./build/advanced_tunnel.json')
type=str, action="store", required=False,
default='./build/advanced_tunnel.json')
args = parser.parse_args()
if not os.path.exists(args.p4info):

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@ -0,0 +1,195 @@
#!/usr/bin/env python2
import argparse
import os
from time import sleep
# NOTE: Appending to the PYTHON_PATH is only required in the `solution` directory.
# It is not required for mycontroller.py in the top-level directory.
import sys
sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
import p4runtime_lib.bmv2
import p4runtime_lib.helper
SWITCH_TO_HOST_PORT = 1
SWITCH_TO_SWITCH_PORT = 2
def writeTunnelRules(p4info_helper, ingress_sw, egress_sw, tunnel_id,
dst_eth_addr, dst_ip_addr):
'''
Installs three rules:
1) An tunnel ingress rule on the ingress switch in the ipv4_lpm table that
encapsulates traffic into a tunnel with the specified ID
2) A transit rule on the ingress switch that forwards traffic based on
the specified ID
3) An tunnel egress rule on the egress switch that decapsulates traffic
with the specified ID and sends it to the host
:param p4info_helper: the P4Info helper
:param ingress_sw: the ingress switch connection
:param egress_sw: the egress switch connection
:param tunnel_id: the specified tunnel ID
:param dst_eth_addr: the destination IP to match in the ingress rule
:param dst_ip_addr: the destination Ethernet address to write in the
egress rule
'''
# 1) Tunnel Ingress Rule
table_entry = p4info_helper.buildTableEntry(
table_name="ipv4_lpm",
match_fields={
"hdr.ipv4.dstAddr": (dst_ip_addr, 32)
},
action_name="myTunnel_ingress",
action_params={
"dst_id": tunnel_id,
})
ingress_sw.WriteTableEntry(table_entry)
print "Installed ingress tunnel rule on %s" % ingress_sw.name
# 2) Tunnel Transit Rule
# The rule will need to be added to the myTunnel_exact table and match on
# the tunnel ID (hdr.myTunnel.dst_id). For our simple topology, transit
# traffic will need to be forwarded on the using the myTunnel_forward action
# on the SWITCH_TO_SWITCH_PORT (port 2).
#
# We will only need on transit rule on the ingress switch because we are
# using a simple topology. In general, you'll need on transit rule for
# each switch in the path (except the last one).
table_entry = p4info_helper.buildTableEntry(
table_name="myTunnel_exact",
match_fields={
"hdr.myTunnel.dst_id": tunnel_id
},
action_name="myTunnel_forward",
action_params={
"port": SWITCH_TO_SWITCH_PORT
})
ingress_sw.WriteTableEntry(table_entry)
print "Installed transit tunnel rule on %s" % ingress_sw.name
# 3) Tunnel Egress Rule
# For our simple topology, the host will always be located on the
# SWITCH_TO_HOST_PORT (port 1).
# In general, you will need to keep track of which port the host is
# connected to.
table_entry = p4info_helper.buildTableEntry(
table_name="myTunnel_exact",
match_fields={
"hdr.myTunnel.dst_id": tunnel_id
},
action_name="myTunnel_egress",
action_params={
"dstAddr": dst_eth_addr,
"port": SWITCH_TO_HOST_PORT
})
egress_sw.WriteTableEntry(table_entry)
print "Installed egress tunnel rule on %s" % egress_sw.name
def readTableRules(p4info_helper, sw):
'''
Reads the table entries from all tables on the switch.
:param p4info_helper: the P4Info helper
:param sw: the switch connection
'''
print '\n----- Reading tables rules for %s -----' % sw.name
for response in sw.ReadTableEntries():
for entity in response.entities:
entry = entity.table_entry
# TODO For extra credit, you can use the p4info_helper to translate
# the IDs the entry to names
table_name = p4info_helper.get_tables_name(entry.table_id)
print '%s: ' % table_name,
for m in entry.match:
print p4info_helper.get_match_field_name(table_name, m.field_id),
print '%r' % (p4info_helper.get_match_field_value(m),),
action = entry.action.action
action_name = p4info_helper.get_actions_name(action.action_id)
print '->', action_name,
for p in action.params:
print p4info_helper.get_action_param_name(action_name, p.param_id),
print '%r' % p.value,
print
def printCounter(p4info_helper, sw, counter_name, index):
'''
Reads the specified counter at the specified index from the switch. In our
program, the index is the tunnel ID. If the index is 0, it will return all
values from the counter.
:param p4info_helper: the P4Info helper
:param sw: the switch connection
:param counter_name: the name of the counter from the P4 program
:param index: the counter index (in our case, the tunnel ID)
'''
for response in sw.ReadCounters(p4info_helper.get_counters_id(counter_name), index):
for entity in response.entities:
counter = entity.counter_entry
print "%s %s %d: %d packets (%d bytes)" % (
sw.name, counter_name, index,
counter.data.packet_count, counter.data.byte_count
)
def main(p4info_file_path, bmv2_file_path):
# Instantiate a P4 Runtime helper from the p4info file
p4info_helper = p4runtime_lib.helper.P4InfoHelper(p4info_file_path)
# Create a switch connection object for s1 and s2;
# this is backed by a P4 Runtime gRPC connection
s1 = p4runtime_lib.bmv2.Bmv2SwitchConnection('s1', address='127.0.0.1:50051')
s2 = p4runtime_lib.bmv2.Bmv2SwitchConnection('s2', address='127.0.0.1:50052')
# Install the P4 program on the switches
s1.SetForwardingPipelineConfig(p4info=p4info_helper.p4info,
bmv2_json_file_path=bmv2_file_path)
print "Installed P4 Program using SetForwardingPipelineConfig on %s" % s1.name
s2.SetForwardingPipelineConfig(p4info=p4info_helper.p4info,
bmv2_json_file_path=bmv2_file_path)
print "Installed P4 Program using SetForwardingPipelineConfig on %s" % s2.name
# Write the rules that tunnel traffic from h1 to h2
writeTunnelRules(p4info_helper, ingress_sw=s1, egress_sw=s2, tunnel_id=100,
dst_eth_addr="00:00:00:00:02:02", dst_ip_addr="10.0.2.2")
# Write the rules that tunnel traffic from h2 to h1
writeTunnelRules(p4info_helper, ingress_sw=s2, egress_sw=s1, tunnel_id=200,
dst_eth_addr="00:00:00:00:01:01", dst_ip_addr="10.0.1.1")
# TODO Uncomment the following two lines to read table entries from s1 and s2
readTableRules(p4info_helper, s1)
readTableRules(p4info_helper, s2)
# Print the tunnel counters every 2 seconds
try:
while True:
sleep(2)
print '\n----- Reading tunnel counters -----'
printCounter(p4info_helper, s1, "ingressTunnelCounter", 100)
printCounter(p4info_helper, s2, "egressTunnelCounter", 100)
printCounter(p4info_helper, s2, "ingressTunnelCounter", 200)
printCounter(p4info_helper, s1, "egressTunnelCounter", 200)
except KeyboardInterrupt:
print " Shutting down."
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='P4Runtime Controller')
parser.add_argument('--p4info', help='p4info proto in text format from p4c',
type=str, action="store", required=False,
default='./build/advanced_tunnel.p4info')
parser.add_argument('--bmv2-json', help='BMv2 JSON file from p4c',
type=str, action="store", required=False,
default='./build/advanced_tunnel.json')
args = parser.parse_args()
if not os.path.exists(args.p4info):
parser.print_help()
print "\np4info file not found: %s\nHave you run 'make'?" % args.p4info
parser.exit(1)
if not os.path.exists(args.bmv2_json):
parser.print_help()
print "\nBMv2 JSON file not found: %s\nHave you run 'make'?" % args.bmv2_json
parser.exit(1)
main(args.p4info, args.bmv2_json)

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@ -0,0 +1,16 @@
{
"hosts": [
"h1",
"h2",
"h3"
],
"switches": {
"s1": {},
"s2": {},
"s3": {}
},
"links": [
["h1", "s1"], ["s1", "s2"], ["s1", "s3"],
["s3", "s2"], ["s2", "h2"], ["s3", "h3"]
]
}

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@ -3,7 +3,10 @@
Vagrant.configure(2) do |config|
config.vm.box = "bento/ubuntu-16.04"
config.vm.define "p4-tutorial" do |tutorial|
end
config.vm.provider "virtualbox" do |vb|
vb.name = "P4 Tutorial" + Time.now.strftime(" %Y-%m-%d")
vb.gui = true
vb.memory = 2048
vb.cpus = 2

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@ -1,6 +1,7 @@
#!/bin/bash
set -x
# Print commands and exit on errors
set -xe
sudo add-apt-repository ppa:webupd8team/sublime-text-3
sudo add-apt-repository ppa:webupd8team/atom
@ -79,3 +80,11 @@ sed -i s@#background=@background=/usr/share/lubuntu/wallpapers/1604-lubuntu-defa
# Disable screensaver
apt-get -y remove light-locker
# Automatically log into the P4 user
cat << EOF | tee -a /etc/lightdm/lightdm.conf.d/10-lightdm.conf
[SeatDefaults]
autologin-user=p4
autologin-user-timeout=0
user-session=Lubuntu
EOF