samples/bpf: add xdp_redirect_map with xdp_prog support

.travis.yml

@@ -0,0 +1,33 @@
+sudo: required
+language: bash
+dist: bionic
+services:
+    - docker
+
+env:
+    global:
+        - PROJECT_NAME='libbpf'
+        - AUTHOR_EMAIL="$(git log -1 --pretty=\"%aE\")"
+        - REPO_ROOT="$TRAVIS_BUILD_DIR"
+        - CI_ROOT="$REPO_ROOT/travis-ci"
+        - VMTEST_ROOT="$CI_ROOT/vmtest"
+
+addons:
+    apt:
+        packages:
+            - qemu-kvm
+            - zstd
+            - binutils-dev
+            - elfutils
+            - libcap-dev
+            - libelf-dev
+            - libdw-dev
+            - python3-docutils
+
+jobs:
+    include:
+        - stage: Builds & Tests
+          name: Kernel LATEST + selftests
+          language: bash
+          env: KERNEL=LATEST
+          script:  $CI_ROOT/vmtest/run_vmtest.sh || travis_terminate 1

samples/bpf/xdp_redirect_map_kern.c

@@ -22,7 +22,7 @@
 struct {
 	__uint(type, BPF_MAP_TYPE_DEVMAP);
 	__uint(key_size, sizeof(int));
-	__uint(value_size, sizeof(int));
+	__uint(value_size, sizeof(struct bpf_devmap_val));
 	__uint(max_entries, 100);
 } tx_port SEC(".maps");
 
@@ -52,6 +52,48 @@ static void swap_src_dst_mac(void *data)
 	p[5] = dst[2];
 }
 
+static __always_inline __u16 csum_fold_helper(__u32 csum)
+{
+	__u32 sum;
+	sum = (csum & 0xffff) + (csum >> 16);
+	sum += (sum >> 16);
+	return ~sum;
+}
+
+static __always_inline __u16 ipv4_csum(__u16 seed, struct iphdr *iphdr_new,
+				       struct iphdr *iphdr_old)
+{
+	__u32 csum, size = sizeof(struct iphdr);
+	csum = bpf_csum_diff((__be32 *)iphdr_old, size,
+			     (__be32 *)iphdr_new, size, seed);
+	return csum_fold_helper(csum);
+}
+
+static void parse_ipv4(void *data, u64 nh_off, void *data_end, u8 ttl)
+{
+	struct iphdr *iph = data + nh_off;
+	struct iphdr iph_old;
+	__u16 csum_old;
+
+	if (iph + 1 > data_end)
+		return;
+
+	iph_old = *iph;
+	csum_old = iph->check;
+	iph->ttl = ttl;
+	iph->check = ipv4_csum(~csum_old, iph, &iph_old);
+}
+
+static void parse_ipv6(void *data, u64 nh_off, void *data_end, u8 hop_limit)
+{
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return;
+
+	ip6h->hop_limit = hop_limit;
+}
+
 SEC("xdp_redirect_map")
 int xdp_redirect_map_prog(struct xdp_md *ctx)
 {
@@ -82,6 +124,36 @@ int xdp_redirect_map_prog(struct xdp_md *ctx)
 	return bpf_redirect_map(&tx_port, vport, 0);
 }
 
+/* This map prog will set new IP ttl based on egress ifindex */
+SEC("xdp_devmap/map_prog")
+int xdp_devmap_prog(struct xdp_md *ctx)
+{
+	char fmt[] = "devmap redirect: egress dev %u with new ttl %u\n";
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	u16 h_proto;
+	u64 nh_off;
+	u8 ttl;
+
+	nh_off = sizeof(struct ethhdr);
+	if (data + nh_off > data_end)
+		return XDP_DROP;
+
+	/* set new ttl based on egress ifindex */
+	ttl = ctx->egress_ifindex % 64;
+
+	h_proto = eth->h_proto;
+	if (h_proto == htons(ETH_P_IP))
+		parse_ipv4(data, nh_off, data_end, ttl);
+	else if (h_proto == htons(ETH_P_IPV6))
+		parse_ipv6(data, nh_off, data_end, ttl);
+
+	bpf_trace_printk(fmt, sizeof(fmt), ctx->egress_ifindex, ttl);
+
+	return XDP_PASS;
+}
+
 /* Redirect require an XDP bpf_prog loaded on the TX device */
 SEC("xdp_redirect_dummy")
 int xdp_redirect_dummy_prog(struct xdp_md *ctx)

samples/bpf/xdp_redirect_map_user.c

@@ -98,12 +98,13 @@ int main(int argc, char **argv)
 {
 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	struct bpf_prog_load_attr prog_load_attr = {
-		.prog_type	= BPF_PROG_TYPE_XDP,
+		.prog_type	= BPF_PROG_TYPE_UNSPEC,
 	};
-	struct bpf_program *prog, *dummy_prog;
+	struct bpf_program *prog, *dummy_prog, *devmap_prog;
+	int prog_fd, dummy_prog_fd, devmap_prog_fd;
+	struct bpf_devmap_val devmap_val;
 	struct bpf_prog_info info = {};
 	__u32 info_len = sizeof(info);
-	int prog_fd, dummy_prog_fd;
 	const char *optstr = "FSN";
 	struct bpf_object *obj;
 	int ret, opt, key = 0;
@@ -157,16 +158,18 @@ int main(int argc, char **argv)
 		return 1;
 
 	prog = bpf_program__next(NULL, obj);
-	dummy_prog = bpf_program__next(prog, obj);
-	if (!prog || !dummy_prog) {
+	devmap_prog = bpf_object__find_program_by_title(obj, "xdp_devmap/map_prog");
+	dummy_prog = bpf_object__find_program_by_title(obj, "xdp_redirect_dummy");
+	if (!prog || !devmap_prog || !dummy_prog) {
 		printf("finding a prog in obj file failed\n");
 		return 1;
 	}
 	/* bpf_prog_load_xattr gives us the pointer to first prog's fd,
-	 * so we're missing only the fd for dummy prog
+	 * so we're missing the fd for devmap and dummy prog
 	 */
+	devmap_prog_fd = bpf_program__fd(devmap_prog);
 	dummy_prog_fd = bpf_program__fd(dummy_prog);
-	if (prog_fd < 0 || dummy_prog_fd < 0) {
+	if (prog_fd < 0 || devmap_prog_fd < 0 || dummy_prog_fd < 0) {
 		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
 		return 1;
 	}
@@ -209,7 +212,9 @@ int main(int argc, char **argv)
 	signal(SIGTERM, int_exit);
 
 	/* populate virtual to physical port map */
-	ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0);
+	devmap_val.bpf_prog.fd = devmap_prog_fd;
+	devmap_val.ifindex = ifindex_out;
+	ret = bpf_map_update_elem(tx_port_map_fd, &key, &devmap_val, 0);
 	if (ret) {
 		perror("bpf_update_elem");
 		goto out;

travis-ci/managers/debian.sh

@@ -0,0 +1,84 @@
+#!/bin/bash
+
+PHASES=(${@:-SETUP RUN RUN_ASAN CLEANUP})
+DEBIAN_RELEASE="${DEBIAN_RELEASE:-testing}"
+CONT_NAME="${CONT_NAME:-libbpf-debian-$DEBIAN_RELEASE}"
+ENV_VARS="${ENV_VARS:-}"
+DOCKER_RUN="${DOCKER_RUN:-docker run}"
+REPO_ROOT="${REPO_ROOT:-$PWD}"
+ADDITIONAL_DEPS=(clang pkg-config gcc-8)
+CFLAGS="-g -O2 -Werror -Wall"
+
+function info() {
+    echo -e "\033[33;1m$1\033[0m"
+}
+
+function error() {
+    echo -e "\033[31;1m$1\033[0m"
+}
+
+function docker_exec() {
+    docker exec $ENV_VARS -it $CONT_NAME "$@"
+}
+
+set -e
+
+source "$(dirname $0)/travis_wait.bash"
+
+for phase in "${PHASES[@]}"; do
+    case $phase in
+        SETUP)
+            info "Setup phase"
+            info "Using Debian $DEBIAN_RELEASE"
+
+            sudo apt-get -y -o Dpkg::Options::="--force-confnew" install docker-ce
+            docker --version
+
+            docker pull debian:$DEBIAN_RELEASE
+            info "Starting container $CONT_NAME"
+            $DOCKER_RUN -v $REPO_ROOT:/build:rw \
+                        -w /build --privileged=true --name $CONT_NAME \
+                        -dit --net=host debian:$DEBIAN_RELEASE /bin/bash
+            docker_exec bash -c "echo deb-src http://deb.debian.org/debian $DEBIAN_RELEASE main >>/etc/apt/sources.list"
+            docker_exec apt-get -y update
+            docker_exec apt-get -y build-dep libelf-dev
+            docker_exec apt-get -y install libelf-dev
+            docker_exec apt-get -y install "${ADDITIONAL_DEPS[@]}"
+            ;;
+        RUN|RUN_CLANG|RUN_GCC8|RUN_ASAN|RUN_CLANG_ASAN|RUN_GCC8_ASAN)
+            if [[ "$phase" = *"CLANG"* ]]; then
+                ENV_VARS="-e CC=clang -e CXX=clang++"
+                CC="clang"
+            elif [[ "$phase" = *"GCC8"* ]]; then
+                ENV_VARS="-e CC=gcc-8 -e CXX=g++-8"
+                CC="gcc-8"
+            else
+                CFLAGS="${CFLAGS} -Wno-stringop-truncation"
+            fi
+            if [[ "$phase" = *"ASAN"* ]]; then
+                CFLAGS="${CFLAGS} -fsanitize=address,undefined"
+            fi
+            docker_exec mkdir build install
+            docker_exec ${CC:-cc} --version
+            info "build"
+	    docker_exec make -j$((4*$(nproc))) CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
+            info "ldd build/libbpf.so:"
+            docker_exec ldd build/libbpf.so
+            if ! docker_exec ldd build/libbpf.so | grep -q libelf; then
+                error "No reference to libelf.so in libbpf.so!"
+                exit 1
+            fi
+            info "install"
+            docker_exec make -j$((4*$(nproc))) -C src OBJDIR=../build DESTDIR=../install install
+            docker_exec rm -rf build install
+            ;;
+        CLEANUP)
+            info "Cleanup phase"
+            docker stop $CONT_NAME
+            docker rm -f $CONT_NAME
+            ;;
+        *)
+            echo >&2 "Unknown phase '$phase'"
+            exit 1
+    esac
+done

travis-ci/managers/travis_wait.bash

@@ -0,0 +1,61 @@
+# This was borrowed from https://github.com/travis-ci/travis-build/tree/master/lib/travis/build/bash
+# to get around https://github.com/travis-ci/travis-ci/issues/9979. It should probably be removed
+# as soon as Travis CI has started to provide an easy way to export the functions to bash scripts.
+
+travis_jigger() {
+  local cmd_pid="${1}"
+  shift
+  local timeout="${1}"
+  shift
+  local count=0
+
+  echo -e "\\n"
+
+  while [[ "${count}" -lt "${timeout}" ]]; do
+    count="$((count + 1))"
+    echo -ne "Still running (${count} of ${timeout}): ${*}\\r"
+    sleep 60
+  done
+
+  echo -e "\\n${ANSI_RED}Timeout (${timeout} minutes) reached. Terminating \"${*}\"${ANSI_RESET}\\n"
+  kill -9 "${cmd_pid}"
+}
+
+travis_wait() {
+  local timeout="${1}"
+
+  if [[ "${timeout}" =~ ^[0-9]+$ ]]; then
+    shift
+  else
+    timeout=20
+  fi
+
+  local cmd=("${@}")
+  local log_file="travis_wait_${$}.log"
+
+  "${cmd[@]}" &>"${log_file}" &
+  local cmd_pid="${!}"
+
+  travis_jigger "${!}" "${timeout}" "${cmd[@]}" &
+  local jigger_pid="${!}"
+  local result
+
+  {
+    set +e
+    wait "${cmd_pid}" 2>/dev/null
+    result="${?}"
+    ps -p"${jigger_pid}" &>/dev/null && kill "${jigger_pid}"
+    set -e
+  }
+
+  if [[ "${result}" -eq 0 ]]; then
+    echo -e "\\n${ANSI_GREEN}The command ${cmd[*]} exited with ${result}.${ANSI_RESET}"
+  else
+    echo -e "\\n${ANSI_RED}The command ${cmd[*]} exited with ${result}.${ANSI_RESET}"
+  fi
+
+  echo -e "\\n${ANSI_GREEN}Log:${ANSI_RESET}\\n"
+  cat "${log_file}"
+
+  return "${result}"
+}

travis-ci/managers/ubuntu.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+set -e
+set -x
+
+RELEASE="bionic"
+
+echo "deb-src http://archive.ubuntu.com/ubuntu/ $RELEASE main restricted universe multiverse" >>/etc/apt/sources.list
+
+apt-get update
+apt-get -y build-dep libelf-dev
+apt-get install -y libelf-dev pkg-config
+
+source "$(dirname $0)/travis_wait.bash"
+
+cd $REPO_ROOT
+
+CFLAGS="-g -O2 -Werror -Wall -fsanitize=address,undefined"
+mkdir build install
+cc --version
+make -j$((4*$(nproc))) CFLAGS="${CFLAGS}" -C ./src -B OBJDIR=../build
+ldd build/libbpf.so
+if ! ldd build/libbpf.so | grep -q libelf; then
+    echo "FAIL: No reference to libelf.so in libbpf.so!"
+    exit 1
+fi
+make -j$((4*$(nproc))) -C src OBJDIR=../build DESTDIR=../install install
+rm -rf build install

travis-ci/vmtest/build_pahole.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+set -eu
+
+source $(cd $(dirname $0) && pwd)/helpers.sh
+
+travis_fold start build_pahole "Building pahole"
+
+CWD=$(pwd)
+REPO_PATH=$1
+PAHOLE_ORIGIN=https://git.kernel.org/pub/scm/devel/pahole/pahole.git
+
+mkdir -p ${REPO_PATH}
+cd ${REPO_PATH}
+git init
+git remote add origin ${PAHOLE_ORIGIN}
+git fetch origin
+git checkout master
+
+mkdir -p build
+cd build
+cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -D__LIB=lib ..
+make -j$((4*$(nproc))) all
+sudo make install
+
+export LD_LIBRARY_PATH=${LD_LIBRARY_PATH:-}:/usr/local/lib
+ldd $(which pahole)
+pahole --version
+
+travis_fold end build_pahole