tools/testing/selftests/net/lib/ksft_setup_loopback.sh
Source file repositories/reference/linux-study-clean/tools/testing/selftests/net/lib/ksft_setup_loopback.sh
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/net/lib/ksft_setup_loopback.sh- Extension
.sh- Size
- 3476 bytes
- Lines
- 112
- Domain
- Support Tooling And Documentation
- Bucket
- tools
- Inferred role
- Support Tooling And Documentation: tools
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Setup script for running ksft tests over a real interface in loopback mode.
# This scripts replaces the historical setup_loopback.sh. It puts
# a (presumably) real hardware interface into loopback mode, creates macvlan
# interfaces on top and places them in a network namespace for isolation.
#
# NETIF env variable must be exported to indicate the real target device.
# Note that the test will override NETIF with one of the macvlans, the
# actual ksft test will only see the macvlans.
#
# Example use:
# export NETIF=eth0
# ./net/lib/ksft_setup_loopback.sh ./drivers/net/gro.py
if [ -z "$NETIF" ]; then
echo "Error: NETIF variable not set"
exit 1
fi
if ! [ -d "/sys/class/net/$NETIF" ]; then
echo "Error: Can't find $NETIF, invalid netdevice"
exit 1
fi
# Save original settings for cleanup
readonly FLUSH_PATH="/sys/class/net/${NETIF}/gro_flush_timeout"
readonly IRQ_PATH="/sys/class/net/${NETIF}/napi_defer_hard_irqs"
FLUSH_TIMEOUT="$(< "${FLUSH_PATH}")"
readonly FLUSH_TIMEOUT
HARD_IRQS="$(< "${IRQ_PATH}")"
readonly HARD_IRQS
SERVER_NS=$(mktemp -u server-XXXXXXXX)
readonly SERVER_NS
CLIENT_NS=$(mktemp -u client-XXXXXXXX)
readonly CLIENT_NS
readonly SERVER_MAC="aa:00:00:00:00:02"
readonly CLIENT_MAC="aa:00:00:00:00:01"
# ksft expects addresses to communicate with remote
export LOCAL_V6=2001:db8:1::1
export REMOTE_V6=2001:db8:1::2
cleanup() {
local exit_code=$?
echo "Cleaning up..."
# Remove macvlan interfaces and namespaces
ip -netns "${SERVER_NS}" link del dev server 2>/dev/null || true
ip netns del "${SERVER_NS}" 2>/dev/null || true
ip -netns "${CLIENT_NS}" link del dev client 2>/dev/null || true
ip netns del "${CLIENT_NS}" 2>/dev/null || true
# Disable loopback
ethtool -K "${NETIF}" loopback off 2>/dev/null || true
sleep 1
echo "${FLUSH_TIMEOUT}" >"${FLUSH_PATH}"
echo "${HARD_IRQS}" >"${IRQ_PATH}"
exit $exit_code
}
trap cleanup EXIT INT TERM
# Enable loopback mode
echo "Enabling loopback on ${NETIF}..."
ethtool -K "${NETIF}" loopback on || {
Annotation
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.