fabric-programmable-networking

name	fabric-programmable-networking
description	Provision P4 Tofino switches, DPDK SmartNICs, BlueField DPUs, and Open vSwitch on FABRIC
allowed-tools	["Read","Grep","Glob","Write","Edit","Bash"]

Instructions

When invoked, generate code for programmable networking on FABRIC. Four main capabilities:

1. P4 Tofino — Barefoot Tofino programmable switches with SDE compilation and table population
2. DPDK SmartNIC — High-performance packet processing with Mellanox ConnectX NICs
3. BlueField DPU — NVIDIA BlueField-3 Data Processing Units with RShim management
4. Open vSwitch (OVS) — Software-defined switching with STP support

Help the user choose the right approach and generate complete setup code.

API Reference

P4 Switch

# Add P4 Tofino switch to slice
switch = slice.add_switch(name="p4-switch", site=site)

# Get switch ports
iface1 = switch.get_interfaces()[0]
iface2 = switch.get_interfaces()[1]

# Interactive command execution (regex prompt matching)
switch.execute(command=[
    ("command", r"expected_prompt_regex", timeout_seconds),
])

# Get logical port numbers
port = switch.get_interfaces()[0].get_device_name()

NIC Models for Programmable Networking

# Standard SR-IOV (10 Gbps virtual function, 1 port)
model = 'NIC_Basic'

# Mellanox ConnectX-5 (25 Gbps dedicated, 2 ports)
model = 'NIC_ConnectX_5'

# Mellanox ConnectX-6 (100 Gbps dedicated, 2 ports)
model = 'NIC_ConnectX_6'

# BlueField-3 DPU (100 Gbps, 2 ports)
model = 'NIC_ConnectX_7_100'

# BlueField-3 DPU (400 Gbps, 2 ports)
model = 'NIC_ConnectX_7_400'

Hardware Info Methods

pci_addr = iface.get_component().get_pci_addr()[0]
mac_addr = iface.get_mac()
os_iface = iface.get_physical_os_interface_name()
dev_name = iface.get_device_name()

BlueField DPU Configuration

bluefield = node.get_component(name='nic1')
output = bluefield.configure()  # Push BFB image via RShim
output = bluefield.configure(commands=['cmd1', 'cmd2'])  # With custom commands

CPU/NUMA Tuning

node.pin_cpu(component_name='nic1')  # Pin vCPUs to NIC's NUMA node
node.numa_tune()                      # Pin memory to same NUMA node

Patterns

P4 Tofino Switch with L2 Network

from fabrictestbed_extensions.fablib.fablib import FablibManager

fablib = FablibManager()

site = fablib.get_random_site()
slice = fablib.new_slice(name="p4-experiment")

# Create L2 networks
net1 = slice.add_l2network(name="net1")
net2 = slice.add_l2network(name="net2")

# Host nodes
node1 = slice.add_node(name="host1", site=site, cores=4, ram=16, disk=50)
iface1 = node1.add_component(model="NIC_Basic", name="nic1").get_interfaces()[0]
iface1.set_mode("auto")
net1.add_interface(iface1)

node2 = slice.add_node(name="host2", site=site, cores=4, ram=16, disk=50)
iface4 = node2.add_component(model="NIC_Basic", name="nic1").get_interfaces()[0]
iface4.set_mode("auto")
net2.add_interface(iface4)

# P4 Tofino switch
switch = slice.add_switch(name="p4-switch", site=site)
sw_iface1 = switch.get_interfaces()[0]
sw_iface2 = switch.get_interfaces()[1]
net1.add_interface(sw_iface1)
net2.add_interface(sw_iface2)

slice.submit()

P4 Compile and Run

switch = slice.get_node(name="p4-switch")

# Upload P4 program
switch.upload_directory("P4_labs", ".")

# Compile P4 program
stdout, stderr = switch.execute(command=[
    ("sde-env-9.13.3", r"\[nix\-shell\(SDE\-9.13.3\):.*\$ ", 10),
    ("p4_build.sh P4_labs/lab1/p4src/basic.p4", r"\[nix\-shell\(SDE-9.13.3\):.*\$ ", 20),
    ("exit", r"\[nix\-shell\(SDE-9.13.3\):.*\$ ", 10),
])

# Start switch daemon (in background thread)
thread = switch.execute_thread(command=[
    ("sde-env-9.13.3", r"\[nix\-shell\(SDE\-9.13.3\):.*\$ ", 10),
    ("sudo $SDE_INSTALL/bin/./bf_kdrv_mod_load $SDE_INSTALL", r"\[nix\-shell\(SDE-9.13.3\):.*\$ ", 20),
    ("run_switchd.sh -p basic", r"bfshell>", 30),
    ("ucli", r"bf-sde>", 10),
    ("pm port-add 1/- 100G NONE", r"bf-sde>", 10),
    ("pm port-add 2/- 100G NONE", r"bf-sde>", 10),
    ("pm port-enb 1/-", r"bf-sde>", 10),
    ("pm port-enb 2/-", r"bf-sde>", 10),
    ("pm show", r"bf-sde>", 10),
    ("sleep infinity", r"bf-sde>", 300),
], output_file="run_switchd.log")

P4 Table Population via bfrt-python

# Get logical port numbers
INGRESS = switch.get_interfaces()[0].get_device_name()
EGRESS = switch.get_interfaces()[1].get_device_name()

# Update setup script with port numbers
switch.execute(
    f"sed -i 's/ingress_logical *= *[0-9]\\+/ingress_logical = {INGRESS}/' "
    f"P4_labs/lab1/bfrt_python/setup.py"
)
switch.execute(
    f"sed -i 's/egress_logical *= *[0-9]\\+/egress_logical = {EGRESS}/' "
    f"P4_labs/lab1/bfrt_python/setup.py"
)

# Run bfshell to populate tables
stdout, stderr = switch.execute(command=[
    ("sde-env-9.13.3", r"\[nix\-shell\(SDE\-9.13.3\):.*\$ ", 10),
    ("run_bfshell.sh --no-status-srv -b ~/P4_labs/lab1/bfrt_python/setup.py",
     r"\[nix\-shell\(SDE\-9.13.3\):.*\$ ", 10),
])

DPDK SmartNIC Setup

site = fablib.get_random_site(
    filter_function=lambda x: x['nic_connectx_6_available'] > 0
)

slice = fablib.new_slice(name="dpdk-experiment")

# L3 network for management
net = slice.add_l3network(name="data-net", type="IPv4")

# L3FWD node with dedicated NIC
l3fwd = slice.add_node(name="l3fwd", site=site, cores=8, ram=32, disk=50)
l3fwd.add_fabnet()
iface1 = l3fwd.add_component(model="NIC_ConnectX_6", name="nic1").get_interfaces()[0]
iface1.set_mode("auto")
net.add_interface(iface1)

# Packet generator node
pktgen = slice.add_node(name="pktgen", site=site, cores=8, ram=32, disk=50)
pktgen.add_fabnet()
iface2 = pktgen.add_component(model="NIC_ConnectX_6", name="nic1").get_interfaces()[0]
iface2.set_mode("auto")
net.add_interface(iface2)

# Post-boot DPDK setup
for n in [l3fwd, pktgen]:
    n.add_post_boot_upload_directory('node_tools', '.')
    n.add_post_boot_execute('chmod +x node_tools/*')
    n.add_post_boot_execute('sudo node_tools/install.sh')

slice.submit()

DPDK IOMMU and Hugepages

for n in slice.get_nodes():
    n.execute(
        f"sudo node_tools/grub.sh {n.get_ram()}",
        quiet=True,
        output_file=f"logs/{n.get_name()}-grub.log",
    )
    n.execute(
        "sudo node_tools/apply_vfio_settings.sh",
        quiet=True,
        output_file=f"logs/{n.get_name()}-vfio.log",
    )

# Reboot required
for n in slice.get_nodes():
    n.execute("sudo reboot")

slice.wait_ssh(timeout=360, interval=10, progress=True)

DPDK Build and Run

# Build DPDK (parallel)
execute_threads = {}
for n in slice.get_nodes():
    execute_threads[n] = n.execute_thread(
        "node_tools/dpdk.sh",
        output_file=f"logs/{n.get_name()}-dpdk.log",
    )
for n, thread in execute_threads.items():
    stdout, stderr = thread.result()

# Run L3FWD
l3fwd_iface = l3fwd.get_interface(network_name="data-net")
pktgen_iface = pktgen.get_interface(network_name="data-net")

print(
    f"cd dpdk-23.07 && sudo ./build/examples/dpdk-l3fwd "
    f"-a {l3fwd_iface.get_component().get_pci_addr()[0]} -c 0x1 -n 4 "
    f"-- -p 0x1 --config=\"(0,0,0)\" "
    f"--eth-dest=0,{pktgen_iface.get_mac().lower()}"
)

# Run Pktgen
print(
    f"sudo ./Builddir/app/pktgen "
    f"-a {pktgen_iface.get_component().get_pci_addr()[0]} -l 0-4 -n 3 -- -P -m [1:3].0"
)

BlueField-3 DPU

site = fablib.get_random_site(
    filter_function=lambda x: x['nic_connectx_7_available'] > 0
)

slice = fablib.new_slice(name="bluefield-experiment")

node = slice.add_node(
    name="bf-node", site=site, cores=8, ram=32, disk=100, image="dpu_ubuntu_24"
)
dpu = node.add_component(model="NIC_ConnectX_7_400", name="nic1")
iface1 = dpu.get_interfaces()[0]
iface2 = dpu.get_interfaces()[1]

net = slice.add_l2network(name="data-net")
iface1.set_mode("auto")
net.add_interface(iface1)

slice.submit()

# Configure BlueField DPU (push BFB image via RShim)
node = slice.get_node(name="bf-node")
bluefield = node.get_component(name="nic1")
output = bluefield.configure()

# Set up RShim management interface
node.execute("sudo ip addr add 192.168.100.1/24 dev tmfifo_net0")
node.execute("sudo ip link set tmfifo_net0 up")

# SSH to DPU ARM cores: ssh ubuntu@192.168.100.2

# Set up NAT for DPU internet access
import ipaddress
ip = ipaddress.ip_address(node.get_management_ip())
if ip.version == 4:
    node.execute("sudo ./node_tools/bf3_rshim.sh --mode ipv4")
else:
    node.execute("sudo ./node_tools/bf3_rshim.sh --mode ipv6")

# Console access to DPU
# screen /dev/rshim0/console

Open vSwitch Deployment

site = fablib.get_random_site()

slice = fablib.new_slice(name="ovs-experiment")

# Bridge node (OVS runs here)
bridge = slice.add_node(
    name="bridge",
    site=site,
    cores=4,
    ram=8,
    disk=50,
    host=f"{site.lower()}-w1.fabric-testbed.net",
)

# Add multiple interfaces for bridging
net1 = slice.add_l2network(name="net1")
net2 = slice.add_l2network(name="net2")

br_iface1 = bridge.add_component(model="NIC_Basic", name="nic1").get_interfaces()[0]
net1.add_interface(br_iface1)

br_iface2 = bridge.add_component(model="NIC_Basic", name="nic2").get_interfaces()[0]
net2.add_interface(br_iface2)

# Host nodes on different physical host (SR-IOV constraint)
host1 = slice.add_node(
    name="host1",
    site=site,
    cores=4,
    ram=8,
    disk=50,
    host=f"{site.lower()}-w2.fabric-testbed.net",
)
h1_iface = host1.add_component(model="NIC_Basic", name="nic1").get_interfaces()[0]
net1.add_interface(h1_iface)

host2 = slice.add_node(
    name="host2",
    site=site,
    cores=4,
    ram=8,
    disk=50,
    host=f"{site.lower()}-w2.fabric-testbed.net",
)
h2_iface = host2.add_component(model="NIC_Basic", name="nic1").get_interfaces()[0]
net2.add_interface(h2_iface)

slice.submit()

# Install and configure OVS
bridge = slice.get_node(name="bridge")
bridge.execute("sudo apt-get update && sudo apt-get -y install openvswitch-switch openvswitch-common net-tools")

# Create OVS bridge and add ports
bridge.execute("sudo ovs-vsctl add-br br0")

for iface in bridge.get_interfaces():
    os_name = iface.get_physical_os_interface_name()
    bridge.execute(f"sudo ovs-vsctl add-port br0 {os_name}")
    bridge.execute(f"sudo ifconfig {os_name} 0")  # Remove IP from physical interface

bridge.execute("sudo ifconfig br0 up")

# Enable Spanning Tree Protocol
bridge.execute("sudo ovs-vsctl set bridge br0 stp_enable=true")

# Verify
stdout, _ = bridge.execute("sudo ovs-appctl stp/show")
print(stdout)

# Configure host IPs
host1 = slice.get_node(name="host1")
os_iface = host1.get_interfaces()[0].get_physical_os_interface_name()
host1.execute(f"sudo ip link set dev {os_iface} up")
host1.execute(f"sudo ip addr add 10.10.10.1/24 dev {os_iface}")

host2 = slice.get_node(name="host2")
os_iface2 = host2.get_interfaces()[0].get_physical_os_interface_name()
host2.execute(f"sudo ip link set dev {os_iface2} up")
host2.execute(f"sudo ip addr add 10.10.10.2/24 dev {os_iface2}")

# Test connectivity through OVS bridge
stdout, _ = host1.execute("ping -c 5 10.10.10.2")
print(stdout)

Important Notes

• P4 Tofino: Uses interactive execute(command=[...]) with regex prompt matching
• DPDK: Requires IOMMU and hugepages (needs reboot after GRUB changes)
• BlueField DPU: Use dpu_ubuntu_24 image; RShim interface at 192.168.100.1/24
• OVS with NIC_Basic: Bridge and host nodes must be on different physical hosts (SR-IOV constraint)
• CPU pinning: Use node.pin_cpu() and node.numa_tune() for DPDK workloads
• Parallel execution: Use node.execute_thread() for long-running installs