mirror of
https://github.com/falcosecurity/falco.git
synced 2025-10-22 12:27:10 +00:00
412 lines
12 KiB
Bash
Executable File
412 lines
12 KiB
Bash
Executable File
#!/usr/bin/env bash
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#
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# Copyright (C) 2019 The Falco Authors.
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#
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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# Simple script that desperately tries to load the kernel instrumentation by
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# looking for it in a bunch of ways. Convenient when running falco inside
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# a container or in other weird environments.
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#
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#
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# Returns 1 if $cos_ver > $base_ver, 0 otherwise
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#
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cos_version_greater()
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{
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if [[ $cos_ver == "${base_ver}" ]]; then
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return 0
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fi
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#
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# COS build numbers are in the format x.y.z
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#
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a=$(echo "${cos_ver}" | cut -d. -f1)
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b=$(echo "${cos_ver}" | cut -d. -f2)
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c=$(echo "${cos_ver}" | cut -d. -f3)
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d=$(echo "${base_ver}" | cut -d. -f1)
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e=$(echo "${base_ver}" | cut -d. -f2)
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f=$(echo "${base_ver}" | cut -d. -f3)
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# Test the first component
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if [[ $a -gt $d ]]; then
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return 1
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elif [[ $d -gt $a ]]; then
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return 0
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fi
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# Test the second component
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if [[ $b -gt $e ]]; then
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return 1
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elif [[ $e -gt $b ]]; then
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return 0
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fi
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# Test the third component
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if [[ $c -gt $f ]]; then
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return 1
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elif [[ $f -gt $c ]]; then
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return 0
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fi
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# If we get here, probably malformatted version string?
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return 0
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}
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get_kernel_config() {
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if [ -f /proc/config.gz ]; then
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echo "Found kernel config at /proc/config.gz"
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KERNEL_CONFIG_PATH=/proc/config.gz
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elif [ -f "/boot/config-${KERNEL_RELEASE}" ]; then
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echo "Found kernel config at /boot/config-${KERNEL_RELEASE}"
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KERNEL_CONFIG_PATH=/boot/config-${KERNEL_RELEASE}
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elif [ -n "${HOST_ROOT}" ] && [ -f "${HOST_ROOT}/boot/config-${KERNEL_RELEASE}" ]; then
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echo "Found kernel config at ${HOST_ROOT}/boot/config-${KERNEL_RELEASE}"
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KERNEL_CONFIG_PATH="${HOST_ROOT}/boot/config-${KERNEL_RELEASE}"
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elif [ -f "/usr/lib/ostree-boot/config-${KERNEL_RELEASE}" ]; then
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echo "Found kernel config at /usr/lib/ostree-boot/config-${KERNEL_RELEASE}"
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KERNEL_CONFIG_PATH="/usr/lib/ostree-boot/config-${KERNEL_RELEASE}"
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elif [ -n "${HOST_ROOT}" ] && [ -f "${HOST_ROOT}/usr/lib/ostree-boot/config-${KERNEL_RELEASE}" ]; then
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echo "Found kernel config at ${HOST_ROOT}/usr/lib/ostree-boot/config-${KERNEL_RELEASE}"
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KERNEL_CONFIG_PATH="${HOST_ROOT}/usr/lib/ostree-boot/config-${KERNEL_RELEASE}"
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elif [ -f "/lib/modules/${KERNEL_RELEASE}/config" ]; then
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# this code works both for native host and agent container assuming that
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# Dockerfile sets up the desired symlink /lib/modules -> $HOST_ROOT/lib/modules
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echo "Found kernel config at /lib/modules/${KERNEL_RELEASE}/config"
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KERNEL_CONFIG_PATH="/lib/modules/${KERNEL_RELEASE}/config"
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fi
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if [ -z "${KERNEL_CONFIG_PATH}" ]; then
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echo "Cannot find kernel config"
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exit 1
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fi
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if [[ "${KERNEL_CONFIG_PATH}" == *.gz ]]; then
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HASH=$(zcat "${KERNEL_CONFIG_PATH}" | md5sum - | cut -d' ' -f1)
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else
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HASH=$(md5sum "${KERNEL_CONFIG_PATH}" | cut -d' ' -f1)
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fi
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}
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load_kernel_module() {
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if ! hash lsmod > /dev/null 2>&1; then
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echo "This program requires lsmod"
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exit 1
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fi
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if ! hash modprobe > /dev/null 2>&1; then
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echo "This program requires modprobe"
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exit 1
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fi
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if ! hash rmmod > /dev/null 2>&1; then
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echo "This program requires rmmod"
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exit 1
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fi
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echo "* Unloading ${PROBE_NAME}, if present"
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rmmod "${PROBE_NAME}" 2>/dev/null
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WAIT_TIME=0
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KMOD_NAME=$(echo "${PROBE_NAME}" | tr "-" "_")
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while lsmod | grep "${KMOD_NAME}" > /dev/null 2>&1 && [ $WAIT_TIME -lt "${MAX_RMMOD_WAIT}" ]; do
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if rmmod "${PROBE_NAME}" 2>/dev/null; then
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echo "* Unloading ${PROBE_NAME} succeeded after ${WAIT_TIME}s"
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break
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fi
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((++WAIT_TIME))
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if (( WAIT_TIME % 5 == 0 )); then
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echo "* ${PROBE_NAME} still loaded, waited ${WAIT_TIME}s (max wait ${MAX_RMMOD_WAIT}s)"
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fi
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sleep 1
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done
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if lsmod | grep "${KMOD_NAME}" > /dev/null 2>&1; then
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echo "* ${PROBE_NAME} seems to still be loaded, hoping the best"
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exit 0
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fi
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# skip dkms on UEK hosts because it will always fail
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if [[ $(uname -r) == *uek* ]]; then
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echo "* Skipping dkms install for UEK host"
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else
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echo "* Running dkms install for ${PACKAGE_NAME}"
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if dkms install -m "${PACKAGE_NAME}" -v "${DRIVER_VERSION}" -k "${KERNEL_RELEASE}"; then
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echo "* Trying to load a dkms ${PROBE_NAME}, if present"
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if insmod "/var/lib/dkms/${PACKAGE_NAME}/${DRIVER_VERSION}/${KERNEL_RELEASE}/${ARCH}/module/${PROBE_NAME}.ko" > /dev/null 2>&1; then
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echo "${PROBE_NAME} found and loaded in dkms"
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exit 0
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elif insmod "/var/lib/dkms/${PACKAGE_NAME}/${DRIVER_VERSION}/${KERNEL_RELEASE}/${ARCH}/module/${PROBE_NAME}.ko.xz" > /dev/null 2>&1; then
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echo "${PROBE_NAME} found and loaded in dkms (xz)"
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exit 0
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else
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echo "* Unable to insmod"
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fi
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else
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DKMS_LOG="/var/lib/dkms/${PACKAGE_NAME}/${DRIVER_VERSION}/build/make.log"
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if [ -f "${DKMS_LOG}" ]; then
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echo "* Running dkms build failed, dumping ${DKMS_LOG}"
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cat "${DKMS_LOG}"
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else
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echo "* Running dkms build failed, couldn't find ${DKMS_LOG}"
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fi
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fi
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fi
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echo "* Trying to load a system ${PROBE_NAME}, if present"
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if modprobe "${PROBE_NAME}" > /dev/null 2>&1; then
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echo "${PROBE_NAME} found and loaded with modprobe"
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exit 0
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fi
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echo "* Trying to find precompiled ${PROBE_NAME} for ${KERNEL_RELEASE}"
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get_kernel_config
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local FALCO_PROBE_FILENAME="${PROBE_NAME}-${DRIVER_VERSION}-${ARCH}-${KERNEL_RELEASE}-${HASH}.ko"
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if [ -f "${HOME}/.falco/${FALCO_PROBE_FILENAME}" ]; then
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echo "Found precompiled module at ~/.falco/${FALCO_PROBE_FILENAME}, loading module"
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insmod "${HOME}/.falco/${FALCO_PROBE_FILENAME}"
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exit $?
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fi
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local URL
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URL=$(echo "${PROBE_URL}/${PACKAGES_REPOSITORY}/sysdig-probe-binaries/${FALCO_PROBE_FILENAME}" | sed s/+/%2B/g)
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echo "* Trying to download precompiled module from ${URL}"
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if curl --create-dirs "${FALCO_PROBE_CURL_OPTIONS}" -o "${HOME}/.falco/${FALCO_PROBE_FILENAME}" "${URL}"; then
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echo "Download succeeded, loading module"
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insmod "${HOME}/.falco/${FALCO_PROBE_FILENAME}"
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exit $?
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else
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echo "Download failed, consider compiling your own ${PROBE_NAME} and loading it or getting in touch with the Falco community"
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exit 1
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fi
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}
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load_bpf_probe() {
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echo "* Mounting debugfs"
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if [ ! -d /sys/kernel/debug/tracing ]; then
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mount -t debugfs nodev /sys/kernel/debug
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fi
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get_kernel_config
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if [ -n "${HOST_ROOT}" ] && [ -f "${HOST_ROOT}/etc/os-release" ]; then
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# shellcheck source=/dev/null
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. "${HOST_ROOT}/etc/os-release"
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if [ "${ID}" == "cos" ]; then
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COS=1
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fi
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fi
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if [ -n "${HOST_ROOT}" ] && [ -f "${HOST_ROOT}/etc/VERSION" ]; then
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MINIKUBE=1
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MINIKUBE_VERSION="$(cat "${HOST_ROOT}/etc/VERSION")"
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fi
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local BPF_PROBE_FILENAME="${BPF_PROBE_NAME}-${DRIVER_VERSION}-${ARCH}-${KERNEL_RELEASE}-${HASH}.o"
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if [ ! -f "${HOME}/.falco/${BPF_PROBE_FILENAME}" ]; then
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local BPF_KERNEL_SOURCES_URL=""
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local STRIP_COMPONENTS=1
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customize_kernel_build() {
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if [ -n "${KERNEL_EXTRA_VERSION}" ]; then
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sed -i "s/LOCALVERSION=\"\"/LOCALVERSION=\"${KERNEL_EXTRA_VERSION}\"/" .config
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fi
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make olddefconfig > /dev/null
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make modules_prepare > /dev/null
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}
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if [ -n "${COS}" ]; then
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echo "* COS detected (build ${BUILD_ID}), using cos kernel headers..."
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BPF_KERNEL_SOURCES_URL="https://storage.googleapis.com/cos-tools/${BUILD_ID}/kernel-headers.tgz"
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KERNEL_EXTRA_VERSION="+"
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STRIP_COMPONENTS=0
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customize_kernel_build() {
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pushd usr/src/* > /dev/null || exit
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# Note: this overrides the KERNELDIR set while untarring the tarball
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KERNELDIR=$(pwd)
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export KERNELDIR
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sed -i '/^#define randomized_struct_fields_start struct {$/d' include/linux/compiler-clang.h
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sed -i '/^#define randomized_struct_fields_end };$/d' include/linux/compiler-clang.h
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popd > /dev/null || exit
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# Might need to configure our own sources depending on COS version
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cos_ver=${BUILD_ID}
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base_ver=11553.0.0
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cos_version_greater
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greater_ret=$?
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if [[ greater_ret -eq 1 ]]; then
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export KBUILD_EXTRA_CPPFLAGS=-DCOS_73_WORKAROUND
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fi
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}
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fi
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if [ -n "${MINIKUBE}" ]; then
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echo "* Minikube detected (${MINIKUBE_VERSION}), using linux kernel sources for minikube kernel"
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local kernel_version
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kernel_version=$(uname -r)
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local -r kernel_version_major=$(echo "${kernel_version}" | cut -d. -f1)
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local -r kernel_version_minor=$(echo "${kernel_version}" | cut -d. -f2)
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local -r kernel_version_patch=$(echo "${kernel_version}" | cut -d. -f3)
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if [ "${kernel_version_patch}" == "0" ]; then
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kernel_version="${kernel_version_major}.${kernel_version_minor}"
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fi
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BPF_KERNEL_SOURCES_URL="http://mirrors.edge.kernel.org/pub/linux/kernel/v${kernel_version_major}.x/linux-${kernel_version}.tar.gz"
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fi
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if [ -n "${BPF_USE_LOCAL_KERNEL_SOURCES}" ]; then
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local -r kernel_version_major=$(uname -r | cut -d. -f1)
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local -r kernel_version=$(uname -r | cut -d- -f1)
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KERNEL_EXTRA_VERSION="-$(uname -r | cut -d- -f2)"
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echo "* Using downloaded kernel sources for kernel version ${kernel_version}..."
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BPF_KERNEL_SOURCES_URL="http://mirrors.edge.kernel.org/pub/linux/kernel/v${kernel_version_major}.x/linux-${kernel_version}.tar.gz"
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fi
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if [ -n "${BPF_KERNEL_SOURCES_URL}" ]; then
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echo "* Downloading ${BPF_KERNEL_SOURCES_URL}"
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mkdir -p /tmp/kernel
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cd /tmp/kernel || exit
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cd "$(mktemp -d -p /tmp/kernel)" || exit
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if ! curl -o kernel-sources.tgz --create-dirs "${FALCO_PROBE_CURL_OPTIONS}" "${BPF_KERNEL_SOURCES_URL}"; then
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exit 1;
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fi
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echo "* Extracting kernel sources"
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mkdir kernel-sources && tar xf kernel-sources.tgz -C kernel-sources --strip-components "${STRIP_COMPONENTS}"
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cd kernel-sources || exit
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KERNELDIR=$(pwd)
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export KERNELDIR
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if [[ "${KERNEL_CONFIG_PATH}" == *.gz ]]; then
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zcat "${KERNEL_CONFIG_PATH}" > .config
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else
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cat "${KERNEL_CONFIG_PATH}" > .config
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fi
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echo "* Configuring kernel"
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customize_kernel_build
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fi
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echo "* Trying to compile BPF probe ${BPF_PROBE_NAME} (${BPF_PROBE_FILENAME})"
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make -C "/usr/src/${PACKAGE_NAME}-${DRIVER_VERSION}/bpf" > /dev/null
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mkdir -p ~/.falco
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mv "/usr/src/${PACKAGE_NAME}-${DRIVER_VERSION}/bpf/probe.o" "${HOME}/.falco/${BPF_PROBE_FILENAME}"
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if [ -n "${BPF_KERNEL_SOURCES_URL}" ]; then
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rm -r /tmp/kernel
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fi
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fi
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if [ ! -f "${HOME}/.falco/${BPF_PROBE_FILENAME}" ]; then
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local URL
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URL=$(echo "${PROBE_URL}/${PACKAGES_REPOSITORY}/sysdig-probe-binaries/${BPF_PROBE_FILENAME}" | sed s/+/%2B/g)
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echo "* Trying to download precompiled BPF probe from ${URL}"
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curl --create-dirs "${FALCO_PROBE_CURL_OPTIONS}" -o "${HOME}/.falco/${BPF_PROBE_FILENAME}" "${URL}"
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fi
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if [ -f "${HOME}/.falco/${BPF_PROBE_FILENAME}" ]; then
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if [ ! -f /proc/sys/net/core/bpf_jit_enable ]; then
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echo "**********************************************************"
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echo "** BPF doesn't have JIT enabled, performance might be **"
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echo "** degraded. Please ensure to run on a kernel with **"
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echo "** CONFIG_BPF_JIT enabled and/or use --net=host if **"
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echo "** running inside a container. **"
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echo "**********************************************************"
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fi
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echo "* BPF probe located, it's now possible to start falco"
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ln -sf "${HOME}/.falco/${BPF_PROBE_FILENAME}" "${HOME}/.falco/${BPF_PROBE_NAME}.o"
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exit $?
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else
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echo "* Failure to find a BPF probe"
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exit 1
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fi
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}
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ARCH=$(uname -m)
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KERNEL_RELEASE=$(uname -r)
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SCRIPT_NAME=$(basename "${0}")
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PROBE_URL=${PROBE_URL:-"@DRIVER_LOOKUP_URL@"}
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if [ -n "$PROBE_INSECURE_DOWNLOAD" ]
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then
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FALCO_PROBE_CURL_OPTIONS=-fsSk
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else
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FALCO_PROBE_CURL_OPTIONS=-fsS
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fi
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MAX_RMMOD_WAIT=60
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if [[ $# -ge 1 ]]; then
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MAX_RMMOD_WAIT=$1
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fi
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if [ -z "${PACKAGES_REPOSITORY}" ]; then
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PACKAGES_REPOSITORY="stable"
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fi
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if [ "${SCRIPT_NAME}" = "falco-driver-loader" ]; then
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DRIVER_VERSION="@PROBE_VERSION@"
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PROBE_NAME="@PROBE_NAME@"
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BPF_PROBE_NAME="@PROBE_NAME@-bpf"
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PACKAGE_NAME="@PACKAGE_NAME@"
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else
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echo "This script must be called as falco-driver-loader"
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exit 1
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fi
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if [ "$(id -u)" != 0 ]; then
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echo "Installer must be run as root (or with sudo)."
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exit 1
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fi
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if ! hash curl > /dev/null 2>&1; then
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echo "This program requires curl"
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exit 1
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fi
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if [ -v FALCO_BPF_PROBE ] || [ "${1}" = "bpf" ]; then
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load_bpf_probe
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else
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load_kernel_module
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fi
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