tests/runtime: add socket_data to test send/receive with data objects

Verifies all send/receive combinations via UDP loopback:
  data → data, string → data, data → string.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: lneto

tests/runtime/run.sh

@@ -11,7 +11,7 @@ DIR="$(dirname "$(readlink -f "$0")")"
 FAILED=0
 
 SEP=""
-for t in "$DIR"/refcnt_leak.sh "$DIR"/resume_shared.sh "$DIR"/resume_mailbox.sh "$DIR"/rcu_shared.sh "$DIR"/opt_guards.sh "$DIR"/opt_skb_single.sh; do
+for t in "$DIR"/refcnt_leak.sh "$DIR"/resume_shared.sh "$DIR"/resume_mailbox.sh "$DIR"/rcu_shared.sh "$DIR"/opt_guards.sh "$DIR"/opt_skb_single.sh "$DIR"/socket_data.sh "$DIR"/socket_data_reject.sh; do
 	echo "${SEP}# --- $(basename "$t") ---"
 	SEP=$'\n'
 	bash "$t" || FAILED=$((FAILED+1))

tests/runtime/socket_data.lua

@@ -0,0 +1,43 @@
+--
+-- SPDX-FileCopyrightText: (c) 2026 Ring Zero Desenvolvimento de Software LTDA
+-- SPDX-License-Identifier: MIT OR GPL-2.0-only
+--
+-- Kernel-side script for the socket_data regression test (see socket_data.sh).
+
+local socket = require("socket")
+local net    = require("net")
+local data   = require("data")
+
+local af   = socket.af
+local sock = socket.sock
+local ip   = socket.ipproto
+local PORT = 19876
+local MSG  = "hello socket data!"
+local SIZE = #MSG
+
+local s = socket.new(af.INET, sock.DGRAM, ip.UDP)
+s:bind(net.aton("127.0.0.1"), PORT)
+
+local sbuf = data.new(SIZE, "single")
+sbuf:setstring(0, MSG)
+local rbuf = data.new(SIZE, "single")
+
+-- data → data
+s:send(sbuf, net.aton("127.0.0.1"), PORT)
+local n = s:receive(rbuf)
+assert(n == SIZE, "data→data: expected " .. SIZE .. " bytes, got " .. tostring(n))
+assert(rbuf:getstring(0, n) == MSG, "data→data: content mismatch")
+
+-- string → data
+s:send(MSG, net.aton("127.0.0.1"), PORT)
+local n2 = s:receive(rbuf)
+assert(n2 == SIZE, "string→data: expected " .. SIZE .. " bytes, got " .. tostring(n2))
+assert(rbuf:getstring(0, n2) == MSG, "string→data: content mismatch")
+
+-- data → string
+s:send(sbuf, net.aton("127.0.0.1"), PORT)
+local str = s:receive(SIZE)
+assert(str == MSG, "data→string: content mismatch")
+
+s:close()
+

tests/runtime/socket_data.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+#
+# SPDX-FileCopyrightText: (c) 2026 Ring Zero Desenvolvimento de Software LTDA
+# SPDX-License-Identifier: MIT OR GPL-2.0-only
+#
+# Tests socket send/receive with data objects via a UDP loopback socket.
+# Verifies valid combinations: data→data, string→data, data→string.
+#
+# Usage: sudo bash tests/runtime/socket_data.sh
+
+SCRIPT="tests/runtime/socket_data"
+MODULE="luasocket"
+
+source "$(dirname "$(readlink -f "$0")")/../lib.sh"
+
+cleanup() { lunatik stop "$SCRIPT" 2>/dev/null; }
+trap cleanup EXIT
+cleanup
+
+ktap_header
+ktap_plan 1
+
+cat /sys/module/$MODULE/refcnt > /dev/null 2>&1 || {
+	echo "# SKIP: $MODULE not loaded"
+	ktap_totals
+	exit 0
+}
+
+mark_dmesg
+
+run_script "$SCRIPT"
+
+check_dmesg || { ktap_totals; exit 1; }
+ktap_pass "socket send/receive with data objects: data→data, string→data, data→string"
+
+ktap_totals
+

tests/runtime/socket_data_reject.lua

@@ -0,0 +1,37 @@
+--
+-- SPDX-FileCopyrightText: (c) 2026 Ring Zero Desenvolvimento de Software LTDA
+-- SPDX-License-Identifier: MIT OR GPL-2.0-only
+--
+-- Kernel-side script for the socket_data_reject regression test (see socket_data_reject.sh).
+
+local socket = require("socket")
+local net    = require("net")
+local data   = require("data")
+
+local af   = socket.af
+local sock = socket.sock
+local ip   = socket.ipproto
+local PORT = 19877
+local SIZE = 16
+
+local s = socket.new(af.INET, sock.DGRAM, ip.UDP)
+s:bind(net.aton("127.0.0.1"), PORT)
+
+-- rejection: wrong-type userdata (socket instead of data)
+local ok, err = pcall(function() s:send(s, net.aton("127.0.0.1"), PORT) end)
+assert(not ok and err:find("bad argument"), "send: wrong type not rejected: " .. tostring(err))
+
+local ok2, err2 = pcall(function() s:receive(s) end)
+assert(not ok2 and err2:find("bad argument"), "receive: wrong type not rejected: " .. tostring(err2))
+
+-- rejection: non-SINGLE (shared) data
+local shared = data.new(SIZE, "shared")
+
+local ok3, err3 = pcall(function() s:send(shared, net.aton("127.0.0.1"), PORT) end)
+assert(not ok3 and err3:find("bad argument"), "send: non-SINGLE data not rejected: " .. tostring(err3))
+
+local ok4, err4 = pcall(function() s:receive(shared) end)
+assert(not ok4 and err4:find("bad argument"), "receive: non-SINGLE data not rejected: " .. tostring(err4))
+
+s:close()
+

tests/runtime/socket_data_reject.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+#
+# SPDX-FileCopyrightText: (c) 2026 Ring Zero Desenvolvimento de Software LTDA
+# SPDX-License-Identifier: MIT OR GPL-2.0-only
+#
+# Verifies that socket send/receive reject wrong-type userdata and non-SINGLE
+# data objects with a proper Lua error rather than crashing the kernel.
+#
+# Usage: sudo bash tests/runtime/socket_data_reject.sh
+
+SCRIPT="tests/runtime/socket_data_reject"
+MODULE="luasocket"
+
+source "$(dirname "$(readlink -f "$0")")/../lib.sh"
+
+cleanup() { lunatik stop "$SCRIPT" 2>/dev/null; }
+trap cleanup EXIT
+cleanup
+
+ktap_header
+ktap_plan 1
+
+cat /sys/module/$MODULE/refcnt > /dev/null 2>&1 || {
+	echo "# SKIP: $MODULE not loaded"
+	ktap_totals
+	exit 0
+}
+
+mark_dmesg
+
+run_script "$SCRIPT"
+
+check_dmesg || { ktap_totals; exit 1; }
+ktap_pass "socket send/receive correctly reject wrong-type and non-SINGLE data"
+
+ktap_totals
+