Example of verifying the client address to ensure it's the expected one.
We expect to receive packets over loopback from 127.0.0.1. The
expected source address is hardcoded in the script. The script works
only for IPv4. To use it with IPv6 you will need to adapt it.
Start the server:
server $ ./udp_stream -4 --script ./examples/check-src-addr.lua
[...]
script=./examples/check-src-addr.lua
total_run_time=10
From another terminal start the client:
client $ ./udp_stream -4 -c
VERSION=1.1.0
all_samples=
port=12867
control_port=12866
host=
local_host=
interval=1.000000
edge_trigger=0
nonblocking=0
logtostderr=0
reuseport=0
dry_run=0
client=1
ipv6=0
ipv4=1
suicide_length=0
buffer_size=16384
test_length=10
num_clients=1
num_threads=1
num_flows=1
maxevents=1000
magic=42
script=
total_run_time=10
invalid_secret_count=0
time_start=0.000000000
utime_start=0.011164
utime_end=0.190635
stime_start=0.001021
stime_end=6.745937
maxrss_start=10408
maxrss_end=10408
minflt_start=667
minflt_end=667
majflt_start=0
majflt_end=0
nvcsw_start=2
nvcsw_end=3
nivcsw_start=0
nivcsw_end=136
client $
Client should terminate successfully.
Back to the server. It should also terminate successfully and report
the measured throughput.
invalid_secret_count=0
time_start=226168.842703565
utime_start=0.012902
utime_end=6.683734
stime_start=0.000983
stime_end=3.292551
maxrss_start=5348
maxrss_end=7376
minflt_start=671
minflt_end=1356
majflt_start=0
majflt_end=0
nvcsw_start=5
nvcsw_end=3551
nivcsw_start=1
nivcsw_end=99
start_index=0
end_index=9
num_samples=10
throughput_Mbps=20551.14
correlation_coefficient=1.00
time_end=226178.842706837
server $
Now reconfigure the loopback so that we can attempt to bind the client
to another address, that is unexpected by the server:
root # ip addr add 127.0.0.2/8 dev lo
root # ip addr show lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet 127.0.0.2/8 scope host secondary lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
Re-run the server as before:
server $ ./udp_stream -4 --script ./examples/check-src-addr.lua
Run the client again but this time tell it to bind to secondary
loopback address:
client $ ./udp_stream -c -L 127.0.0.2
You should see the server complain about the unexpected source address
and abort:
Wrong source address! Expected 127.0.0.1, but got 127.0.0.2
server $