tools: bpftool: support creating and dumping outer maps

.travis.yml

@@ -0,0 +1,32 @@
+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
+
+jobs:
+    include:
+        - stage: Builds & Tests
+          name: Kernel LATEST + selftests
+          language: bash
+          env: KERNEL=LATEST
+          script:  $CI_ROOT/vmtest/run_vmtest.sh || travis_terminate 1

tools/bpf/bpftool/Documentation/bpftool-map.rst

@@ -23,7 +23,8 @@ MAP COMMANDS
 
 |	**bpftool** **map** { **show** | **list** }   [*MAP*]
 |	**bpftool** **map create**     *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
-|		**entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
+|		**entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**inner_map** *MAP*] \
+|		[**dev** *NAME*]
 |	**bpftool** **map dump**       *MAP*
 |	**bpftool** **map update**     *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
 |	**bpftool** **map lookup**     *MAP* [**key** *DATA*]
@@ -67,14 +68,19 @@ DESCRIPTION
 		  maps. On such kernels bpftool will automatically emit this
 		  information as well.
 
-	**bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE*  **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
+	**bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE*  **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**inner_map** *MAP*] [**dev** *NAME*]
 		  Create a new map with given parameters and pin it to *bpffs*
 		  as *FILE*.
 
 		  *FLAGS* should be an integer which is the combination of
 		  desired flags, e.g. 1024 for **BPF_F_MMAPABLE** (see bpf.h
 		  UAPI header for existing flags).
 
+		  To create maps of type array-of-maps or hash-of-maps, the
+		  **inner_map** keyword must be used to pass an inner map. The
+		  kernel needs it to collect metadata related to the inner maps
+		  that the new map will work with.
+
 		  Keyword **dev** expects a network interface name, and is used
 		  to request hardware offload for the map.
 

tools/bpf/bpftool/bash-completion/bpftool

@@ -709,16 +709,36 @@ _bpftool()
                                                    "$cur" ) )
                             return 0
                             ;;
-                        key|value|flags|name|entries)
+                        key|value|flags|entries)
                             return 0
                             ;;
+                        inner_map)
+                            COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )
+                            return 0
+                            ;;
+                        id)
+                            _bpftool_get_map_ids
+                            ;;
+                        name)
+                            case $pprev in
+                                inner_map)
+                                    _bpftool_get_map_names
+                                    ;;
+                                *)
+                                    return 0
+                                    ;;
+                            esac
+                            ;;
                         *)
                             _bpftool_once_attr 'type'
                             _bpftool_once_attr 'key'
                             _bpftool_once_attr 'value'
                             _bpftool_once_attr 'entries'
                             _bpftool_once_attr 'name'
                             _bpftool_once_attr 'flags'
+                            if _bpftool_search_list 'array_of_maps' 'hash_of_maps'; then
+                                _bpftool_once_attr 'inner_map'
+                            fi
                             _bpftool_once_attr 'dev'
                             return 0
                             ;;

tools/bpf/bpftool/map.c

@@ -739,10 +739,6 @@ static int dump_map_elem(int fd, void *key, void *value,
 	/* lookup error handling */
 	lookup_errno = errno;
 
-	if (map_is_map_of_maps(map_info->type) ||
-	    map_is_map_of_progs(map_info->type))
-		return 0;
-
 	if (json_output) {
 		jsonw_start_object(json_wtr);
 		jsonw_name(json_wtr, "key");
@@ -1247,7 +1243,7 @@ static int do_create(int argc, char **argv)
 {
 	struct bpf_create_map_attr attr = { NULL, };
 	const char *pinfile;
-	int err, fd;
+	int err = -1, fd;
 
 	if (!REQ_ARGS(7))
 		return -1;
@@ -1262,13 +1258,13 @@ static int do_create(int argc, char **argv)
 
 			if (attr.map_type) {
 				p_err("map type already specified");
-				return -1;
+				goto exit;
 			}
 
 			attr.map_type = map_type_from_str(*argv);
 			if ((int)attr.map_type < 0) {
 				p_err("unrecognized map type: %s", *argv);
-				return -1;
+				goto exit;
 			}
 			NEXT_ARG();
 		} else if (is_prefix(*argv, "name")) {
@@ -1277,61 +1273,79 @@ static int do_create(int argc, char **argv)
 		} else if (is_prefix(*argv, "key")) {
 			if (parse_u32_arg(&argc, &argv, &attr.key_size,
 					  "key size"))
-				return -1;
+				goto exit;
 		} else if (is_prefix(*argv, "value")) {
 			if (parse_u32_arg(&argc, &argv, &attr.value_size,
 					  "value size"))
-				return -1;
+				goto exit;
 		} else if (is_prefix(*argv, "entries")) {
 			if (parse_u32_arg(&argc, &argv, &attr.max_entries,
 					  "max entries"))
-				return -1;
+				goto exit;
 		} else if (is_prefix(*argv, "flags")) {
 			if (parse_u32_arg(&argc, &argv, &attr.map_flags,
 					  "flags"))
-				return -1;
+				goto exit;
 		} else if (is_prefix(*argv, "dev")) {
 			NEXT_ARG();
 
 			if (attr.map_ifindex) {
 				p_err("offload device already specified");
-				return -1;
+				goto exit;
 			}
 
 			attr.map_ifindex = if_nametoindex(*argv);
 			if (!attr.map_ifindex) {
 				p_err("unrecognized netdevice '%s': %s",
 				      *argv, strerror(errno));
-				return -1;
+				goto exit;
 			}
 			NEXT_ARG();
+		} else if (is_prefix(*argv, "inner_map")) {
+			struct bpf_map_info info = {};
+			__u32 len = sizeof(info);
+			int inner_map_fd;
+
+			NEXT_ARG();
+			if (!REQ_ARGS(2))
+				usage();
+			inner_map_fd = map_parse_fd_and_info(&argc, &argv,
+							     &info, &len);
+			if (inner_map_fd < 0)
+				return -1;
+			attr.inner_map_fd = inner_map_fd;
 		} else {
 			p_err("unknown arg %s", *argv);
-			return -1;
+			goto exit;
 		}
 	}
 
 	if (!attr.name) {
 		p_err("map name not specified");
-		return -1;
+		goto exit;
 	}
 
 	set_max_rlimit();
 
 	fd = bpf_create_map_xattr(&attr);
 	if (fd < 0) {
 		p_err("map create failed: %s", strerror(errno));
-		return -1;
+		goto exit;
 	}
 
 	err = do_pin_fd(fd, pinfile);
 	close(fd);
 	if (err)
-		return err;
+		goto exit;
 
 	if (json_output)
 		jsonw_null(json_wtr);
-	return 0;
+
+exit:
+	if (attr.inner_map_fd > 0)
+		close(attr.inner_map_fd);
+
+	return err;
 }
 
 static int do_pop_dequeue(int argc, char **argv)
@@ -1417,7 +1431,7 @@ static int do_help(int argc, char **argv)
 		"Usage: %1$s %2$s { show | list }   [MAP]\n"
 		"       %1$s %2$s create     FILE type TYPE key KEY_SIZE value VALUE_SIZE \\\n"
 		"                                  entries MAX_ENTRIES name NAME [flags FLAGS] \\\n"
-		"                                  [dev NAME]\n"
+		"                                  [inner_map MAP] [dev NAME]\n"
 		"       %1$s %2$s dump       MAP\n"
 		"       %1$s %2$s update     MAP [key DATA] [value VALUE] [UPDATE_FLAGS]\n"
 		"       %1$s %2$s lookup     MAP [key DATA]\n"

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}"
+}