wolfssh/scripts/fwd.test.expect

#!/usr/bin/env -S expect -f
#
# SSH Tunnel Test Script
#
# Tests an SSH tunnel using wolfSSH and netcat (nc).
#
# Architecture:
#
#   [nc client] --plain--> :12345 [wolfssh client]
#                                       |
#                                      SSH
#                                       |
#                               [wolfssh server] :ephem --plain--> :11111 [nc server]
#
# The nc client sends each line of a Lorem Ipsum paragraph through the tunnel
# to the nc server one at a time. The server echoes each line back. Both sides
# verify receipt of every line.
#
# Ports used:
#   11111  - nc server (plain text backend)
#   12345  - wolfssh client listener (plain text, nc connects here)
#   22222  - wolfSSH rendezvous (SSH, internal use only)
#
# Requirements: nc (netcat), expect

set timeout 30

# Logs / ready file. Under --enable-debug builds wolfSSH's WLOG output is
# voluminous; if we let it write to expect's spawned pty, the pty buffer
# fills and the process blocks in write(), which can stall portfwd inside
# its select() loop before it ever sends the channel-open. Redirect to
# regular files instead, and use portfwd's -R ready file for sync.
set srv_log "/tmp/fwd.test.echoserver.[pid].log"
set clt_log "/tmp/fwd.test.portfwd.[pid].log"
set clt_ready "/tmp/fwd.test.portfwd.[pid].ready"
file delete -force $srv_log $clt_log $clt_ready

set lorem_lines {
    {Lorem ipsum dolor sit amet, consectetur adipiscing elit,}
    {sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.}
    {Ut enim ad minim veniam, quis nostrud exercitation ullamco}
    {laboris nisi ut aliquip ex ea commodo consequat.}
    {Duis aute irure dolor in reprehenderit in voluptate velit esse}
    {cillum dolore eu fugiat nulla pariatur.}
    {Excepteur sint occaecat cupidatat non proident, sunt in culpa qui}
    {officia deserunt mollit anim id est laborum.}
}

# PIDs for cleanup
set nc_server_pid   ""
set wolfssh_srv_pid ""
set wolfssh_clt_pid ""
set nc_client_pid   ""

# --- Cleanup -----------------------------------------------------------------
proc cleanup {} {
    global nc_client_pid wolfssh_clt_pid wolfssh_srv_pid nc_server_pid
    global srv_log clt_log clt_ready

    puts "\n--- Cleaning up ---"
    foreach pid [list $nc_client_pid $wolfssh_clt_pid $wolfssh_srv_pid $nc_server_pid] {
        if {$pid ne ""} {
            catch {exec kill $pid}
        }
    }
    file delete -force $srv_log $clt_log $clt_ready
    puts "Done."
}

# --- Fail helper -------------------------------------------------------------
proc fail {msg} {
    puts "\n\[FAIL\] $msg"
    cleanup
    exit 1
}

# --- Check prerequisites -----------------------------------------------------
foreach tool {nc} {
    if {[auto_execok $tool] eq ""} {
        puts "ERROR: '$tool' not found in PATH"
        exit 1
    }
}

# --- [1] Start nc server -----------------------------------------------------
puts "\n\[1\] Starting nc server: nc -l 11111"
spawn nc -l 11111
set nc_server_id  $spawn_id
set nc_server_pid [exp_pid]
puts "    PID $nc_server_pid - waiting for a connection..."

# --- [2] Start wolfssh server ------------------------------------------------
puts "\n\[2\] Starting wolfssh server..."
spawn sh -c "exec ./examples/echoserver/echoserver -1 -f >$srv_log 2>&1"
set wolfssh_srv_id  $spawn_id
set wolfssh_srv_pid [exp_pid]
puts "    PID $wolfssh_srv_pid - waiting for a connection..."

# --- [3] Start wolfssh client ------------------------------------------------
puts "\n\[3\] Starting wolfssh client (plain:12345 -> 11111)..."
spawn sh -c "exec ./examples/portfwd/portfwd -u jill -P upthehill -f 12345 -t 11111 -R $clt_ready >$clt_log 2>&1"
set wolfssh_clt_id  $spawn_id
set wolfssh_clt_pid [exp_pid]

# portfwd writes the listening port to $clt_ready once SSH is up.
set elapsed 0
while {![file exists $clt_ready] && $elapsed < $timeout} {
    sleep 1
    incr elapsed
}
if {![file exists $clt_ready]} {
    fail "Timed out waiting for wolfssh client to start (no $clt_ready)"
}
puts "    wolfssh client ready (PID $wolfssh_clt_pid)."

# --- [4] Start nc client -----------------------------------------------------
puts "\n\[4\] Starting nc client: nc localhost 12345"
spawn nc localhost 12345
set nc_client_id  $spawn_id
set nc_client_pid [exp_pid]
puts "    PID $nc_client_pid"

# Allow the TCP handshake and SSH negotiation to complete
sleep 1

# --- [5] Send each line, verify receipt, echo back, verify echo --------------
set n [llength $lorem_lines]
set i 0
foreach line $lorem_lines {
    incr i
    puts "\n\[5.$i/$n\] Client sending: \"$line\""
    send -i $nc_client_id "$line\n"

    expect {
        -i $nc_server_id
        -ex $line {
            puts "       \[PASS\] Server received line $i."
        }
        timeout {
            fail "Server did not receive line $i within ${timeout}s"
        }
    }

    send -i $nc_server_id "$line\n"

    expect {
        -i $nc_client_id
        -ex $line {
            puts "       \[PASS\] Client received echo of line $i."
        }
        timeout {
            fail "Client did not receive echo of line $i within ${timeout}s"
        }
    }
}

# --- Done --------------------------------------------------------------------
puts "\n=== TEST PASSED ===\n"

cleanup
exit 0