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Merge pull request #2 from marian-babik/main
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removed exp/act conversion; added debug statements
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@marian-babik
marian-babik committed Jan 23, 2023
2 parents 52a26c9 + 6d3fe60 commit ae50b16
Showing 1 changed file with 26 additions and 30 deletions.
56 changes: 26 additions & 30 deletions scitags/backends/ebpf_rhel8.py
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Expand Up @@ -20,8 +20,6 @@

from bcc import BPF
from pyroute2 import IPRoute
from pyroute2.netlink import NetlinkError

import ctypes
import socket
import ipaddress
Expand Down Expand Up @@ -67,7 +65,7 @@
addrport.ip6_hi = ip6->dst_hi;
addrport.ip6_lo = ip6->dst_lo;
// TCP
// TCP
if (ip6->next_header == 6)
{
struct tcp_t *tcp = cursor_advance(cursor, sizeof(*tcp));
Expand All @@ -79,12 +77,12 @@
u64 *flowlabel = flowlabel_table.lookup(&addrport);
if (delete)
if (delete)
{
flowlabel_table.delete(&addrport);
tobedeleted.delete(&addrport);
}
else if (flowlabel)
else if (flowlabel)
{
ip6->flow_label = *flowlabel;
}
Expand All @@ -100,33 +98,41 @@
"""


class fourtuple(ctypes.Structure):
_fields_ = [("ip6_hi", ctypes.c_ulong), ("ip6_lo", ctypes.c_ulong), ("dport", ctypes.c_ushort), ("sport", ctypes.c_ushort)]


# Load eBPF program
log.debug('Loading eBPF')
b = BPF(text=text, debug=0)
flowlabel_table = b.get_table('flowlabel_table')
tobedeleted = b.get_table('tobedeleted')
fn = b.load_func("set_flow_label", BPF.SCHED_CLS)
log.debug('eBPF load completed')

# Attach to network interface (get from config)
log.debug('Attaching to network interface {}'.format(config['NETWORK_INTERFACE']))
if 'NETWORK_INTERFACE' in config.keys():
interface = config['NETWORK_INTERFACE']
idx = ipr.link_lookup(ifname=interface)[0]
else:
err = 'eBPF backend requires network interface to be specified'
log.error(err)
raise scitags.FlowIdException(err)
log.debug('eBPF attached')

# Clean up, in case backend crashed last time
try:
ipr.tc("del", "sfq", idx, "1:")
except NetlinkError:
except:
pass

ipr.tc("add", "sfq", idx, "1:")
ipr.tc("add-filter", "bpf", idx, ":1", fd=fn.fd,
name=fn.name, parent="1:", action="ok", classid=1)
log.debug('ipr.tc add-filter success')


# Function to put together flow label including entropy bits
def bitpattern(exp_id, act_id):
Expand All @@ -141,7 +147,7 @@ def bitpattern(exp_id, act_id):
exp_id_swapped = exp_id_swapped + exp_id[i]

exp_id = exp_id_swapped

# Packet marking specification wants 3 random numbers
# First is two bits, second is one bit, third is two bits
random1 = random.randrange(4)
Expand All @@ -152,11 +158,15 @@ def bitpattern(exp_id, act_id):
random3 = format(random3, '#04b')

# Stitch the 20-digit binary number together, Frankenstyle
log.debug('flow binary: 00'+exp_id[2:]+'0'+act_id[2:]+'00')
log.debug('flow decimal: {}'.format(int('00'+exp_id[2:]+'0'+act_id[2:]+'00', 2)))
flowlabel = random1 + exp_id[2:] + random2[2:] + act_id[2:] + random3[2:]
log.debug(hex(int(flowlabel, 2)))

# Return as integer
return int(flowlabel, 2)



def run(flow_queue, term_event, flow_map, ip_config):
# Stolen from udp_firefly backend
while not term_event.is_set():
Expand All @@ -166,39 +176,25 @@ def run(flow_queue, term_event, flow_map, ip_config):
continue

if flow_id.state == "start":
if flow_id.exp not in flow_map['experiments'].keys():
err = 'Failed to map experiment ({}) to id'.format(flow_id.exp)
log.error(err)

# Clean up, or backend won't be able to restart
ipr.tc("del", "sfq", idx, "1:")
raise scitags.FlowIdException(err)

exp_id = flow_map['experiments'][flow_id.exp]
exp_id = flow_id.exp

if not flow_id.act:
act_id = 0
elif flow_id.act in flow_map['activities'][exp_id].keys():
act_id = flow_map['activities'][exp_id][flow_id.act]
else:
err = 'Failed to map activity ({}/{}) to id'.format(flow_id.exp, flow_id.act)
log.error(err)

# Clean up, or backend won't be able to restart
ipr.tc("del", "sfq", idx, "1:")
raise scitags.FlowIdException(err)
act_id = flow_id.act

# New stuff starts here
try:
# Need to break up the IPv6 address into halves
log.debug(flow_id)
ip6 = ipaddress.IPv6Address(flow_id.dst).exploded
ip6_hi = int(ip6[0:4] + ip6[5:9] + ip6[10:14] + ip6[15:19], 16)
ip6_lo = int(ip6[20:24] + ip6[25:29] + ip6[30:34] + ip6[35:39], 16)
dport = flow_id.dst_port
sport = flow_id.src_port

key = fourtuple(ip6_hi, ip6_lo, dport, sport)

# Get the bitpattern, including entropy bits
flowlabel = bitpattern(exp_id, act_id)

Expand All @@ -216,7 +212,7 @@ def run(flow_queue, term_event, flow_map, ip_config):
# I don't think we want the backend to crash here?
#raise scitags.FlowIdException(err)

elif flow_id.state == "end":
elif flow_id.state == "end":
try:
ip6 = ipaddress.IPv6Address(flow_id.dst).exploded
ip6_hi = int(ip6[0:4] + ip6[5:9] + ip6[10:14] + ip6[15:19], 16)
Expand All @@ -226,7 +222,7 @@ def run(flow_queue, term_event, flow_map, ip_config):

key = fourtuple(ip6_hi, ip6_lo, dport, sport)

# Remove IP from BPF hash
# Remove IP from BPF hash
# This needs kernel 5.6 at least; have to do it differently for RHEL 8
#flowlabel_table.items_delete_batch(ip6_hi, ip6_lo)

Expand All @@ -235,7 +231,7 @@ def run(flow_queue, term_event, flow_map, ip_config):
log.info(ip6 + " removed from flowlabel table")
log.debug("Source port is " + str(sport))
log.debug("Destination port is " + str(dport))

except ipaddress.AddressValueError:
err = 'Flow label marking only possible with IPv6'
log.error(err)
Expand All @@ -244,4 +240,4 @@ def run(flow_queue, term_event, flow_map, ip_config):
#raise scitags.FlowIdException(err)

# Clean up
ipr.tc("del", "sfq", idx, "1:")
ipr.tc("del", "sfq", idx, "1:")

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