move libbpf_android into loader subdirectory
The only (real) user is the platform bpfloader binary.
This is a library purely to facilitate testing.
It's easier to develop / code-search if everything is in the same directory.
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Iebe8a5c4f8bb9ada220acec6ed8c1be0fc9d438c
diff --git a/loader/Android.bp b/loader/Android.bp
index da45531..087ae27 100644
--- a/loader/Android.bp
+++ b/loader/Android.bp
@@ -14,10 +14,8 @@
// limitations under the License.
//
-//
-// bpfLoad binary
-//
package {
+ default_team: "trendy_team_fwk_core_networking",
// http://go/android-license-faq
// A large-scale-change added 'default_applicable_licenses' to import
// the below license kinds from "system_bpf_license":
@@ -25,6 +23,70 @@
default_applicable_licenses: ["system_bpf_license"],
}
+cc_library {
+ name: "libbpf_android",
+ vendor_available: false,
+ host_supported: false,
+ target: {
+ android: {
+ srcs: [
+ "Loader.cpp",
+ ],
+ sanitize: {
+ misc_undefined: ["integer"],
+ },
+ },
+ },
+
+ shared_libs: [
+ "libbase",
+ "libutils",
+ "liblog",
+ ],
+ header_libs: [
+ "bpf_headers",
+ ],
+ export_header_lib_headers: [
+ "bpf_headers",
+ ],
+ export_include_dirs: ["include"],
+
+ defaults: ["bpf_defaults"],
+ cflags: [
+ "-Werror",
+ "-Wall",
+ "-Wextra",
+ ],
+}
+
+cc_test {
+ name: "libbpf_load_test",
+ test_suites: ["general-tests"],
+ header_libs: ["bpf_headers"],
+ srcs: [
+ "BpfLoadTest.cpp",
+ ],
+ defaults: ["bpf_defaults"],
+ cflags: [
+ "-Wall",
+ "-Werror",
+ "-Wno-error=unused-variable",
+ ],
+ static_libs: ["libgmock"],
+ shared_libs: [
+ "libbpf_android",
+ "libbpf_bcc",
+ "libbase",
+ "liblog",
+ "libutils",
+ ],
+
+ data: [
+ ":bpfLoadTpProg.o",
+ ],
+ require_root: true,
+}
+
cc_binary {
name: "bpfloader",
diff --git a/loader/BpfLoadTest.cpp b/loader/BpfLoadTest.cpp
new file mode 100644
index 0000000..f3a8f85
--- /dev/null
+++ b/loader/BpfLoadTest.cpp
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/file.h>
+#include <android-base/macros.h>
+#include <gtest/gtest.h>
+#include <libbpf.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <iostream>
+#include "bpf/BpfMap.h"
+#include "bpf/BpfUtils.h"
+#include "include/libbpf_android.h"
+
+using ::testing::TestWithParam;
+
+namespace android {
+namespace bpf {
+
+class BpfLoadTest : public TestWithParam<std::string> {
+ protected:
+ BpfLoadTest() {}
+ int mProgFd;
+ std::string mTpProgPath;
+ std::string mTpNeverLoadProgPath;
+ std::string mTpMapPath;;
+
+ void SetUp() {
+ mTpProgPath = "/sys/fs/bpf/prog_" + GetParam() + "_tracepoint_sched_sched_switch";
+ unlink(mTpProgPath.c_str());
+
+ mTpNeverLoadProgPath = "/sys/fs/bpf/prog_" + GetParam() + "_tracepoint_sched_sched_wakeup";
+ unlink(mTpNeverLoadProgPath.c_str());
+
+ mTpMapPath = "/sys/fs/bpf/map_" + GetParam() + "_cpu_pid_map";
+ unlink(mTpMapPath.c_str());
+
+ auto progPath = android::base::GetExecutableDirectory() + "/" + GetParam() + ".o";
+ bool critical = true;
+
+ bpf_prog_type kAllowed[] = {
+ BPF_PROG_TYPE_UNSPEC,
+ };
+
+ Location loc = {
+ .dir = "",
+ .prefix = "",
+ .allowedDomainBitmask = 0,
+ .allowedProgTypes = kAllowed,
+ .allowedProgTypesLength = arraysize(kAllowed),
+ };
+ EXPECT_EQ(android::bpf::loadProg(progPath.c_str(), &critical, loc), -1);
+
+ EXPECT_EQ(android::bpf::loadProg(progPath.c_str(), &critical), 0);
+ EXPECT_EQ(false, critical);
+
+ mProgFd = retrieveProgram(mTpProgPath.c_str());
+ EXPECT_GT(mProgFd, 0);
+
+ int ret = bpf_attach_tracepoint(mProgFd, "sched", "sched_switch");
+ EXPECT_NE(ret, 0);
+ }
+
+ void TearDown() {
+ close(mProgFd);
+ unlink(mTpProgPath.c_str());
+ unlink(mTpMapPath.c_str());
+ }
+
+ void checkMapNonZero() {
+ // The test program installs a tracepoint on sched:sched_switch
+ // and expects the kernel to populate a PID corresponding to CPU
+ android::bpf::BpfMap<uint32_t, uint32_t> m(mTpMapPath.c_str());
+
+ // Wait for program to run a little
+ sleep(1);
+
+ int non_zero = 0;
+ const auto iterFunc = [&non_zero](const uint32_t& key, const uint32_t& val,
+ BpfMap<uint32_t, uint32_t>& map) {
+ if (val && !non_zero) {
+ non_zero = 1;
+ }
+
+ UNUSED(key);
+ UNUSED(map);
+ return base::Result<void>();
+ };
+
+ EXPECT_RESULT_OK(m.iterateWithValue(iterFunc));
+ EXPECT_EQ(non_zero, 1);
+ }
+
+ void checkKernelVersionEnforced() {
+ EXPECT_EQ(retrieveProgram(mTpNeverLoadProgPath.c_str()), -1);
+ EXPECT_EQ(errno, ENOENT);
+ }
+};
+
+INSTANTIATE_TEST_SUITE_P(BpfLoadTests, BpfLoadTest, ::testing::Values("bpfLoadTpProg"));
+
+TEST_P(BpfLoadTest, bpfCheckMap) {
+ checkMapNonZero();
+}
+
+TEST_P(BpfLoadTest, bpfCheckMinKernelVersionEnforced) {
+ checkKernelVersionEnforced();
+}
+
+} // namespace bpf
+} // namespace android
diff --git a/loader/Loader.cpp b/loader/Loader.cpp
new file mode 100644
index 0000000..305c60e
--- /dev/null
+++ b/loader/Loader.cpp
@@ -0,0 +1,1051 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "LibBpfLoader"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/bpf.h>
+#include <linux/elf.h>
+#include <log/log.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "BpfSyscallWrappers.h"
+#include "bpf/BpfUtils.h"
+#include "bpf/bpf_map_def.h"
+#include "include/libbpf_android.h"
+
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <optional>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include <android-base/cmsg.h>
+#include <android-base/file.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+
+#define BPF_FS_PATH "/sys/fs/bpf/"
+
+// Size of the BPF log buffer for verifier logging
+#define BPF_LOAD_LOG_SZ 0xfffff
+
+// Unspecified attach type is 0 which is BPF_CGROUP_INET_INGRESS.
+#define BPF_ATTACH_TYPE_UNSPEC BPF_CGROUP_INET_INGRESS
+
+using android::base::StartsWith;
+using android::base::unique_fd;
+using std::ifstream;
+using std::ios;
+using std::optional;
+using std::string;
+using std::vector;
+
+namespace android {
+namespace bpf {
+
+static unsigned int page_size = static_cast<unsigned int>(getpagesize());
+
+constexpr const char* lookupSelinuxContext(const domain d, const char* const unspecified = "") {
+ switch (d) {
+ case domain::unspecified: return unspecified;
+ case domain::platform: return "fs_bpf";
+ case domain::vendor: return "fs_bpf_vendor";
+ case domain::loader: return "fs_bpf_loader";
+ default: return "(unrecognized)";
+ }
+}
+
+domain getDomainFromSelinuxContext(const char s[BPF_SELINUX_CONTEXT_CHAR_ARRAY_SIZE]) {
+ for (domain d : AllDomains) {
+ // Not sure how to enforce this at compile time, so abort() bpfloader at boot instead
+ if (strlen(lookupSelinuxContext(d)) >= BPF_SELINUX_CONTEXT_CHAR_ARRAY_SIZE) abort();
+ if (!strncmp(s, lookupSelinuxContext(d), BPF_SELINUX_CONTEXT_CHAR_ARRAY_SIZE)) return d;
+ }
+ ALOGW("ignoring unrecognized selinux_context '%-32s'", s);
+ // We should return 'unrecognized' here, however: returning unspecified will
+ // result in the system simply using the default context, which in turn
+ // will allow future expansion by adding more restrictive selinux types.
+ // Older bpfloader will simply ignore that, and use the less restrictive default.
+ // This does mean you CANNOT later add a *less* restrictive type than the default.
+ //
+ // Note: we cannot just abort() here as this might be a mainline module shipped optional update
+ return domain::unspecified;
+}
+
+constexpr const char* lookupPinSubdir(const domain d, const char* const unspecified = "") {
+ switch (d) {
+ case domain::unspecified: return unspecified;
+ case domain::platform: return "/";
+ case domain::vendor: return "vendor/";
+ case domain::loader: return "loader/";
+ default: return "(unrecognized)";
+ }
+};
+
+domain getDomainFromPinSubdir(const char s[BPF_PIN_SUBDIR_CHAR_ARRAY_SIZE]) {
+ for (domain d : AllDomains) {
+ // Not sure how to enforce this at compile time, so abort() bpfloader at boot instead
+ if (strlen(lookupPinSubdir(d)) >= BPF_PIN_SUBDIR_CHAR_ARRAY_SIZE) abort();
+ if (!strncmp(s, lookupPinSubdir(d), BPF_PIN_SUBDIR_CHAR_ARRAY_SIZE)) return d;
+ }
+ ALOGE("unrecognized pin_subdir '%-32s'", s);
+ // pin_subdir affects the object's full pathname,
+ // and thus using the default would change the location and thus our code's ability to find it,
+ // hence this seems worth treating as a true error condition.
+ //
+ // Note: we cannot just abort() here as this might be a mainline module shipped optional update
+ // However, our callers will treat this as an error, and stop loading the specific .o,
+ // which will fail bpfloader if the .o is marked critical.
+ return domain::unrecognized;
+}
+
+static string pathToObjName(const string& path) {
+ // extract everything after the final slash, ie. this is the filename 'foo@1.o' or 'bar.o'
+ string filename = android::base::Split(path, "/").back();
+ // strip off everything from the final period onwards (strip '.o' suffix), ie. 'foo@1' or 'bar'
+ string name = filename.substr(0, filename.find_last_of('.'));
+ // strip any potential @1 suffix, this will leave us with just 'foo' or 'bar'
+ // this can be used to provide duplicate programs (mux based on the bpfloader version)
+ return name.substr(0, name.find_last_of('@'));
+}
+
+typedef struct {
+ const char* name;
+ enum bpf_prog_type type;
+ enum bpf_attach_type expected_attach_type;
+} sectionType;
+
+/*
+ * Map section name prefixes to program types, the section name will be:
+ * SECTION(<prefix>/<name-of-program>)
+ * For example:
+ * SECTION("tracepoint/sched_switch_func") where sched_switch_funcs
+ * is the name of the program, and tracepoint is the type.
+ *
+ * However, be aware that you should not be directly using the SECTION() macro.
+ * Instead use the DEFINE_(BPF|XDP)_(PROG|MAP)... & LICENSE/CRITICAL macros.
+ */
+sectionType sectionNameTypes[] = {
+ {"kprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC},
+ {"kretprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC},
+ {"perf_event/", BPF_PROG_TYPE_PERF_EVENT, BPF_ATTACH_TYPE_UNSPEC},
+ {"skfilter/", BPF_PROG_TYPE_SOCKET_FILTER, BPF_ATTACH_TYPE_UNSPEC},
+ {"tracepoint/", BPF_PROG_TYPE_TRACEPOINT, BPF_ATTACH_TYPE_UNSPEC},
+ {"uprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC},
+ {"uretprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC},
+};
+
+typedef struct {
+ enum bpf_prog_type type;
+ enum bpf_attach_type expected_attach_type;
+ string name;
+ vector<char> data;
+ vector<char> rel_data;
+ optional<struct bpf_prog_def> prog_def;
+
+ unique_fd prog_fd; /* fd after loading */
+} codeSection;
+
+static int readElfHeader(ifstream& elfFile, Elf64_Ehdr* eh) {
+ elfFile.seekg(0);
+ if (elfFile.fail()) return -1;
+
+ if (!elfFile.read((char*)eh, sizeof(*eh))) return -1;
+
+ return 0;
+}
+
+/* Reads all section header tables into an Shdr array */
+static int readSectionHeadersAll(ifstream& elfFile, vector<Elf64_Shdr>& shTable) {
+ Elf64_Ehdr eh;
+ int ret = 0;
+
+ ret = readElfHeader(elfFile, &eh);
+ if (ret) return ret;
+
+ elfFile.seekg(eh.e_shoff);
+ if (elfFile.fail()) return -1;
+
+ /* Read shdr table entries */
+ shTable.resize(eh.e_shnum);
+
+ if (!elfFile.read((char*)shTable.data(), (eh.e_shnum * eh.e_shentsize))) return -ENOMEM;
+
+ return 0;
+}
+
+/* Read a section by its index - for ex to get sec hdr strtab blob */
+static int readSectionByIdx(ifstream& elfFile, int id, vector<char>& sec) {
+ vector<Elf64_Shdr> shTable;
+ int ret = readSectionHeadersAll(elfFile, shTable);
+ if (ret) return ret;
+
+ elfFile.seekg(shTable[id].sh_offset);
+ if (elfFile.fail()) return -1;
+
+ sec.resize(shTable[id].sh_size);
+ if (!elfFile.read(sec.data(), shTable[id].sh_size)) return -1;
+
+ return 0;
+}
+
+/* Read whole section header string table */
+static int readSectionHeaderStrtab(ifstream& elfFile, vector<char>& strtab) {
+ Elf64_Ehdr eh;
+ int ret = readElfHeader(elfFile, &eh);
+ if (ret) return ret;
+
+ ret = readSectionByIdx(elfFile, eh.e_shstrndx, strtab);
+ if (ret) return ret;
+
+ return 0;
+}
+
+/* Get name from offset in strtab */
+static int getSymName(ifstream& elfFile, int nameOff, string& name) {
+ int ret;
+ vector<char> secStrTab;
+
+ ret = readSectionHeaderStrtab(elfFile, secStrTab);
+ if (ret) return ret;
+
+ if (nameOff >= (int)secStrTab.size()) return -1;
+
+ name = string((char*)secStrTab.data() + nameOff);
+ return 0;
+}
+
+/* Reads a full section by name - example to get the GPL license */
+static int readSectionByName(const char* name, ifstream& elfFile, vector<char>& data) {
+ vector<char> secStrTab;
+ vector<Elf64_Shdr> shTable;
+ int ret;
+
+ ret = readSectionHeadersAll(elfFile, shTable);
+ if (ret) return ret;
+
+ ret = readSectionHeaderStrtab(elfFile, secStrTab);
+ if (ret) return ret;
+
+ for (int i = 0; i < (int)shTable.size(); i++) {
+ char* secname = secStrTab.data() + shTable[i].sh_name;
+ if (!secname) continue;
+
+ if (!strcmp(secname, name)) {
+ vector<char> dataTmp;
+ dataTmp.resize(shTable[i].sh_size);
+
+ elfFile.seekg(shTable[i].sh_offset);
+ if (elfFile.fail()) return -1;
+
+ if (!elfFile.read((char*)dataTmp.data(), shTable[i].sh_size)) return -1;
+
+ data = dataTmp;
+ return 0;
+ }
+ }
+ return -2;
+}
+
+unsigned int readSectionUint(const char* name, ifstream& elfFile, unsigned int defVal) {
+ vector<char> theBytes;
+ int ret = readSectionByName(name, elfFile, theBytes);
+ if (ret) {
+ ALOGD("Couldn't find section %s (defaulting to %u [0x%x]).", name, defVal, defVal);
+ return defVal;
+ } else if (theBytes.size() < sizeof(unsigned int)) {
+ ALOGE("Section %s too short (defaulting to %u [0x%x]).", name, defVal, defVal);
+ return defVal;
+ } else {
+ // decode first 4 bytes as LE32 uint, there will likely be more bytes due to alignment.
+ unsigned int value = static_cast<unsigned char>(theBytes[3]);
+ value <<= 8;
+ value += static_cast<unsigned char>(theBytes[2]);
+ value <<= 8;
+ value += static_cast<unsigned char>(theBytes[1]);
+ value <<= 8;
+ value += static_cast<unsigned char>(theBytes[0]);
+ ALOGI("Section %s value is %u [0x%x]", name, value, value);
+ return value;
+ }
+}
+
+static int readSectionByType(ifstream& elfFile, int type, vector<char>& data) {
+ int ret;
+ vector<Elf64_Shdr> shTable;
+
+ ret = readSectionHeadersAll(elfFile, shTable);
+ if (ret) return ret;
+
+ for (int i = 0; i < (int)shTable.size(); i++) {
+ if ((int)shTable[i].sh_type != type) continue;
+
+ vector<char> dataTmp;
+ dataTmp.resize(shTable[i].sh_size);
+
+ elfFile.seekg(shTable[i].sh_offset);
+ if (elfFile.fail()) return -1;
+
+ if (!elfFile.read((char*)dataTmp.data(), shTable[i].sh_size)) return -1;
+
+ data = dataTmp;
+ return 0;
+ }
+ return -2;
+}
+
+static bool symCompare(Elf64_Sym a, Elf64_Sym b) {
+ return (a.st_value < b.st_value);
+}
+
+static int readSymTab(ifstream& elfFile, int sort, vector<Elf64_Sym>& data) {
+ int ret, numElems;
+ Elf64_Sym* buf;
+ vector<char> secData;
+
+ ret = readSectionByType(elfFile, SHT_SYMTAB, secData);
+ if (ret) return ret;
+
+ buf = (Elf64_Sym*)secData.data();
+ numElems = (secData.size() / sizeof(Elf64_Sym));
+ data.assign(buf, buf + numElems);
+
+ if (sort) std::sort(data.begin(), data.end(), symCompare);
+ return 0;
+}
+
+static enum bpf_prog_type getFuseProgType() {
+ int result = BPF_PROG_TYPE_UNSPEC;
+ ifstream("/sys/fs/fuse/bpf_prog_type_fuse") >> result;
+ return static_cast<bpf_prog_type>(result);
+}
+
+static enum bpf_prog_type getSectionType(string& name) {
+ for (auto& snt : sectionNameTypes)
+ if (StartsWith(name, snt.name)) return snt.type;
+
+ // TODO Remove this code when fuse-bpf is upstream and this BPF_PROG_TYPE_FUSE is fixed
+ if (StartsWith(name, "fuse/")) return getFuseProgType();
+
+ return BPF_PROG_TYPE_UNSPEC;
+}
+
+static enum bpf_attach_type getExpectedAttachType(string& name) {
+ for (auto& snt : sectionNameTypes)
+ if (StartsWith(name, snt.name)) return snt.expected_attach_type;
+ return BPF_ATTACH_TYPE_UNSPEC;
+}
+
+static string getSectionName(enum bpf_prog_type type)
+{
+ for (auto& snt : sectionNameTypes)
+ if (snt.type == type)
+ return string(snt.name);
+
+ return "UNKNOWN SECTION NAME " + std::to_string(type);
+}
+
+static int readProgDefs(ifstream& elfFile, vector<struct bpf_prog_def>& pd) {
+ vector<char> pdData;
+ int ret = readSectionByName("progs", elfFile, pdData);
+ if (ret) return ret;
+
+ if (pdData.size() % sizeof(struct bpf_prog_def)) {
+ ALOGE("readProgDefs failed due to improper sized progs section, %zu %% %zu != 0",
+ pdData.size(), sizeof(struct bpf_prog_def));
+ return -1;
+ };
+
+ pd.resize(pdData.size() / sizeof(struct bpf_prog_def));
+ memcpy(pd.data(), pdData.data(), pdData.size());
+ return 0;
+}
+
+static int getSectionSymNames(ifstream& elfFile, const string& sectionName, vector<string>& names,
+ optional<unsigned> symbolType = std::nullopt) {
+ int ret;
+ string name;
+ vector<Elf64_Sym> symtab;
+ vector<Elf64_Shdr> shTable;
+
+ ret = readSymTab(elfFile, 1 /* sort */, symtab);
+ if (ret) return ret;
+
+ /* Get index of section */
+ ret = readSectionHeadersAll(elfFile, shTable);
+ if (ret) return ret;
+
+ int sec_idx = -1;
+ for (int i = 0; i < (int)shTable.size(); i++) {
+ ret = getSymName(elfFile, shTable[i].sh_name, name);
+ if (ret) return ret;
+
+ if (!name.compare(sectionName)) {
+ sec_idx = i;
+ break;
+ }
+ }
+
+ /* No section found with matching name*/
+ if (sec_idx == -1) {
+ ALOGW("No %s section could be found in elf object", sectionName.c_str());
+ return -1;
+ }
+
+ for (int i = 0; i < (int)symtab.size(); i++) {
+ if (symbolType.has_value() && ELF_ST_TYPE(symtab[i].st_info) != symbolType) continue;
+
+ if (symtab[i].st_shndx == sec_idx) {
+ string s;
+ ret = getSymName(elfFile, symtab[i].st_name, s);
+ if (ret) return ret;
+ names.push_back(s);
+ }
+ }
+
+ return 0;
+}
+
+static bool IsAllowed(bpf_prog_type type, const bpf_prog_type* allowed, size_t numAllowed) {
+ if (allowed == nullptr) return true;
+
+ for (size_t i = 0; i < numAllowed; i++) {
+ if (allowed[i] == BPF_PROG_TYPE_UNSPEC) {
+ if (type == getFuseProgType()) return true;
+ } else if (type == allowed[i])
+ return true;
+ }
+
+ return false;
+}
+
+/* Read a section by its index - for ex to get sec hdr strtab blob */
+static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs,
+ const bpf_prog_type* allowed, size_t numAllowed) {
+ vector<Elf64_Shdr> shTable;
+ int entries, ret = 0;
+
+ ret = readSectionHeadersAll(elfFile, shTable);
+ if (ret) return ret;
+ entries = shTable.size();
+
+ vector<struct bpf_prog_def> pd;
+ ret = readProgDefs(elfFile, pd);
+ if (ret) return ret;
+ vector<string> progDefNames;
+ ret = getSectionSymNames(elfFile, "progs", progDefNames);
+ if (!pd.empty() && ret) return ret;
+
+ for (int i = 0; i < entries; i++) {
+ string name;
+ codeSection cs_temp;
+ cs_temp.type = BPF_PROG_TYPE_UNSPEC;
+
+ ret = getSymName(elfFile, shTable[i].sh_name, name);
+ if (ret) return ret;
+
+ enum bpf_prog_type ptype = getSectionType(name);
+
+ if (ptype == BPF_PROG_TYPE_UNSPEC) continue;
+
+ if (!IsAllowed(ptype, allowed, numAllowed)) {
+ ALOGE("Program type %s not permitted here", getSectionName(ptype).c_str());
+ return -1;
+ }
+
+ // This must be done before '/' is replaced with '_'.
+ cs_temp.expected_attach_type = getExpectedAttachType(name);
+
+ string oldName = name;
+
+ // convert all slashes to underscores
+ std::replace(name.begin(), name.end(), '/', '_');
+
+ cs_temp.type = ptype;
+ cs_temp.name = name;
+
+ ret = readSectionByIdx(elfFile, i, cs_temp.data);
+ if (ret) return ret;
+ ALOGD("Loaded code section %d (%s)", i, name.c_str());
+
+ vector<string> csSymNames;
+ ret = getSectionSymNames(elfFile, oldName, csSymNames, STT_FUNC);
+ if (ret || !csSymNames.size()) return ret;
+ for (size_t i = 0; i < progDefNames.size(); ++i) {
+ if (!progDefNames[i].compare(csSymNames[0] + "_def")) {
+ cs_temp.prog_def = pd[i];
+ break;
+ }
+ }
+
+ /* Check for rel section */
+ if (cs_temp.data.size() > 0 && i < entries) {
+ ret = getSymName(elfFile, shTable[i + 1].sh_name, name);
+ if (ret) return ret;
+
+ if (name == (".rel" + oldName)) {
+ ret = readSectionByIdx(elfFile, i + 1, cs_temp.rel_data);
+ if (ret) return ret;
+ ALOGD("Loaded relo section %d (%s)", i, name.c_str());
+ }
+ }
+
+ if (cs_temp.data.size() > 0) {
+ cs.push_back(std::move(cs_temp));
+ ALOGD("Adding section %d to cs list", i);
+ }
+ }
+ return 0;
+}
+
+static int getSymNameByIdx(ifstream& elfFile, int index, string& name) {
+ vector<Elf64_Sym> symtab;
+ int ret = 0;
+
+ ret = readSymTab(elfFile, 0 /* !sort */, symtab);
+ if (ret) return ret;
+
+ if (index >= (int)symtab.size()) return -1;
+
+ return getSymName(elfFile, symtab[index].st_name, name);
+}
+
+static bool mapMatchesExpectations(const unique_fd& fd, const string& mapName,
+ const struct bpf_map_def& mapDef, const enum bpf_map_type type) {
+ // Assuming fd is a valid Bpf Map file descriptor then
+ // all the following should always succeed on a 4.14+ kernel.
+ // If they somehow do fail, they'll return -1 (and set errno),
+ // which should then cause (among others) a key_size mismatch.
+ int fd_type = bpfGetFdMapType(fd);
+ int fd_key_size = bpfGetFdKeySize(fd);
+ int fd_value_size = bpfGetFdValueSize(fd);
+ int fd_max_entries = bpfGetFdMaxEntries(fd);
+ int fd_map_flags = bpfGetFdMapFlags(fd);
+
+ // DEVMAPs are readonly from the bpf program side's point of view, as such
+ // the kernel in kernel/bpf/devmap.c dev_map_init_map() will set the flag
+ int desired_map_flags = (int)mapDef.map_flags;
+ if (type == BPF_MAP_TYPE_DEVMAP || type == BPF_MAP_TYPE_DEVMAP_HASH)
+ desired_map_flags |= BPF_F_RDONLY_PROG;
+
+ // The .h file enforces that this is a power of two, and page size will
+ // also always be a power of two, so this logic is actually enough to
+ // force it to be a multiple of the page size, as required by the kernel.
+ unsigned int desired_max_entries = mapDef.max_entries;
+ if (type == BPF_MAP_TYPE_RINGBUF) {
+ if (desired_max_entries < page_size) desired_max_entries = page_size;
+ }
+
+ // The following checks should *never* trigger, if one of them somehow does,
+ // it probably means a bpf .o file has been changed/replaced at runtime
+ // and bpfloader was manually rerun (normally it should only run *once*
+ // early during the boot process).
+ // Another possibility is that something is misconfigured in the code:
+ // most likely a shared map is declared twice differently.
+ // But such a change should never be checked into the source tree...
+ if ((fd_type == type) &&
+ (fd_key_size == (int)mapDef.key_size) &&
+ (fd_value_size == (int)mapDef.value_size) &&
+ (fd_max_entries == (int)desired_max_entries) &&
+ (fd_map_flags == desired_map_flags)) {
+ return true;
+ }
+
+ ALOGE("bpf map name %s mismatch: desired/found: "
+ "type:%d/%d key:%u/%d value:%u/%d entries:%u/%d flags:%u/%d",
+ mapName.c_str(), type, fd_type, mapDef.key_size, fd_key_size, mapDef.value_size,
+ fd_value_size, mapDef.max_entries, fd_max_entries, desired_map_flags, fd_map_flags);
+ return false;
+}
+
+static int createMaps(const char* elfPath, ifstream& elfFile, vector<unique_fd>& mapFds,
+ const char* prefix, const unsigned long long allowedDomainBitmask) {
+ int ret;
+ vector<char> mdData;
+ vector<struct bpf_map_def> md;
+ vector<string> mapNames;
+ string objName = pathToObjName(string(elfPath));
+
+ ret = readSectionByName("maps", elfFile, mdData);
+ if (ret == -2) return 0; // no maps to read
+ if (ret) return ret;
+
+ if (mdData.size() % sizeof(struct bpf_map_def)) {
+ ALOGE("createMaps failed due to improper sized maps section, %zu %% %zu != 0",
+ mdData.size(), sizeof(struct bpf_map_def));
+ return -1;
+ }
+ md.resize(mdData.size() / sizeof(struct bpf_map_def));
+ memcpy(md.data(), mdData.data(), mdData.size());
+
+ ret = getSectionSymNames(elfFile, "maps", mapNames);
+ if (ret) return ret;
+
+ unsigned kvers = kernelVersion();
+
+ for (int i = 0; i < (int)mapNames.size(); i++) {
+ if (md[i].zero != 0) abort();
+
+ if (kvers < md[i].min_kver) {
+ ALOGI("skipping map %s which requires kernel version 0x%x >= 0x%x",
+ mapNames[i].c_str(), kvers, md[i].min_kver);
+ mapFds.push_back(unique_fd());
+ continue;
+ }
+
+ if (kvers >= md[i].max_kver) {
+ ALOGI("skipping map %s which requires kernel version 0x%x < 0x%x",
+ mapNames[i].c_str(), kvers, md[i].max_kver);
+ mapFds.push_back(unique_fd());
+ continue;
+ }
+
+ enum bpf_map_type type = md[i].type;
+ if (type == BPF_MAP_TYPE_DEVMAP_HASH && !isAtLeastKernelVersion(5, 4, 0)) {
+ // On Linux Kernels older than 5.4 this map type doesn't exist, but it can kind
+ // of be approximated: HASH has the same userspace visible api.
+ // However it cannot be used by ebpf programs in the same way.
+ // Since bpf_redirect_map() only requires 4.14, a program using a DEVMAP_HASH map
+ // would fail to load (due to trying to redirect to a HASH instead of DEVMAP_HASH).
+ // One must thus tag any BPF_MAP_TYPE_DEVMAP_HASH + bpf_redirect_map() using
+ // programs as being 5.4+...
+ type = BPF_MAP_TYPE_HASH;
+ }
+
+ // The .h file enforces that this is a power of two, and page size will
+ // also always be a power of two, so this logic is actually enough to
+ // force it to be a multiple of the page size, as required by the kernel.
+ unsigned int max_entries = md[i].max_entries;
+ if (type == BPF_MAP_TYPE_RINGBUF) {
+ if (max_entries < page_size) max_entries = page_size;
+ }
+
+ domain selinux_context = getDomainFromSelinuxContext(md[i].selinux_context);
+ if (specified(selinux_context)) {
+ if (!inDomainBitmask(selinux_context, allowedDomainBitmask)) {
+ ALOGE("map %s has invalid selinux_context of %d (allowed bitmask 0x%llx)",
+ mapNames[i].c_str(), selinux_context, allowedDomainBitmask);
+ return -EINVAL;
+ }
+ ALOGI("map %s selinux_context [%-32s] -> %d -> '%s' (%s)", mapNames[i].c_str(),
+ md[i].selinux_context, selinux_context, lookupSelinuxContext(selinux_context),
+ lookupPinSubdir(selinux_context));
+ }
+
+ domain pin_subdir = getDomainFromPinSubdir(md[i].pin_subdir);
+ if (unrecognized(pin_subdir)) return -ENOTDIR;
+ if (specified(pin_subdir)) {
+ if (!inDomainBitmask(pin_subdir, allowedDomainBitmask)) {
+ ALOGE("map %s has invalid pin_subdir of %d (allowed bitmask 0x%llx)",
+ mapNames[i].c_str(), pin_subdir, allowedDomainBitmask);
+ return -EINVAL;
+ }
+ ALOGI("map %s pin_subdir [%-32s] -> %d -> '%s'", mapNames[i].c_str(), md[i].pin_subdir,
+ pin_subdir, lookupPinSubdir(pin_subdir));
+ }
+
+ // Format of pin location is /sys/fs/bpf/<pin_subdir|prefix>map_<objName>_<mapName>
+ // except that maps shared across .o's have empty <objName>
+ // Note: <objName> refers to the extension-less basename of the .o file (without @ suffix).
+ string mapPinLoc = string(BPF_FS_PATH) + lookupPinSubdir(pin_subdir, prefix) + "map_" +
+ (md[i].shared ? "" : objName) + "_" + mapNames[i];
+ bool reuse = false;
+ unique_fd fd;
+ int saved_errno;
+
+ if (access(mapPinLoc.c_str(), F_OK) == 0) {
+ fd.reset(mapRetrieveRO(mapPinLoc.c_str()));
+ saved_errno = errno;
+ ALOGD("bpf_create_map reusing map %s, ret: %d", mapNames[i].c_str(), fd.get());
+ reuse = true;
+ } else {
+ union bpf_attr req = {
+ .map_type = type,
+ .key_size = md[i].key_size,
+ .value_size = md[i].value_size,
+ .max_entries = max_entries,
+ .map_flags = md[i].map_flags,
+ };
+ strlcpy(req.map_name, mapNames[i].c_str(), sizeof(req.map_name));
+ fd.reset(bpf(BPF_MAP_CREATE, req));
+ saved_errno = errno;
+ ALOGD("bpf_create_map name %s, ret: %d", mapNames[i].c_str(), fd.get());
+ }
+
+ if (!fd.ok()) return -saved_errno;
+
+ // When reusing a pinned map, we need to check the map type/sizes/etc match, but for
+ // safety (since reuse code path is rare) run these checks even if we just created it.
+ // We assume failure is due to pinned map mismatch, hence the 'NOT UNIQUE' return code.
+ if (!mapMatchesExpectations(fd, mapNames[i], md[i], type)) return -ENOTUNIQ;
+
+ if (!reuse) {
+ if (specified(selinux_context)) {
+ string createLoc = string(BPF_FS_PATH) + lookupPinSubdir(selinux_context) +
+ "tmp_map_" + objName + "_" + mapNames[i];
+ ret = bpfFdPin(fd, createLoc.c_str());
+ if (ret) {
+ int err = errno;
+ ALOGE("create %s -> %d [%d:%s]", createLoc.c_str(), ret, err, strerror(err));
+ return -err;
+ }
+ ret = renameat2(AT_FDCWD, createLoc.c_str(),
+ AT_FDCWD, mapPinLoc.c_str(), RENAME_NOREPLACE);
+ if (ret) {
+ int err = errno;
+ ALOGE("rename %s %s -> %d [%d:%s]", createLoc.c_str(), mapPinLoc.c_str(), ret,
+ err, strerror(err));
+ return -err;
+ }
+ } else {
+ ret = bpfFdPin(fd, mapPinLoc.c_str());
+ if (ret) {
+ int err = errno;
+ ALOGE("pin %s -> %d [%d:%s]", mapPinLoc.c_str(), ret, err, strerror(err));
+ return -err;
+ }
+ }
+ ret = chmod(mapPinLoc.c_str(), md[i].mode);
+ if (ret) {
+ int err = errno;
+ ALOGE("chmod(%s, 0%o) = %d [%d:%s]", mapPinLoc.c_str(), md[i].mode, ret, err,
+ strerror(err));
+ return -err;
+ }
+ ret = chown(mapPinLoc.c_str(), (uid_t)md[i].uid, (gid_t)md[i].gid);
+ if (ret) {
+ int err = errno;
+ ALOGE("chown(%s, %u, %u) = %d [%d:%s]", mapPinLoc.c_str(), md[i].uid, md[i].gid,
+ ret, err, strerror(err));
+ return -err;
+ }
+ }
+
+ int mapId = bpfGetFdMapId(fd);
+ if (mapId == -1) {
+ ALOGE("bpfGetFdMapId failed, ret: %d [%d]", mapId, errno);
+ } else {
+ ALOGI("map %s id %d", mapPinLoc.c_str(), mapId);
+ }
+
+ mapFds.push_back(std::move(fd));
+ }
+
+ return ret;
+}
+
+/* For debugging, dump all instructions */
+static void dumpIns(char* ins, int size) {
+ for (int row = 0; row < size / 8; row++) {
+ ALOGE("%d: ", row);
+ for (int j = 0; j < 8; j++) {
+ ALOGE("%3x ", ins[(row * 8) + j]);
+ }
+ ALOGE("\n");
+ }
+}
+
+/* For debugging, dump all code sections from cs list */
+static void dumpAllCs(vector<codeSection>& cs) {
+ for (int i = 0; i < (int)cs.size(); i++) {
+ ALOGE("Dumping cs %d, name %s", int(i), cs[i].name.c_str());
+ dumpIns((char*)cs[i].data.data(), cs[i].data.size());
+ ALOGE("-----------");
+ }
+}
+
+static void applyRelo(void* insnsPtr, Elf64_Addr offset, int fd) {
+ int insnIndex;
+ struct bpf_insn *insn, *insns;
+
+ insns = (struct bpf_insn*)(insnsPtr);
+
+ insnIndex = offset / sizeof(struct bpf_insn);
+ insn = &insns[insnIndex];
+
+ // Occasionally might be useful for relocation debugging, but pretty spammy
+ if (0) {
+ ALOGD("applying relo to instruction at byte offset: %llu, "
+ "insn offset %d, insn %llx",
+ (unsigned long long)offset, insnIndex, *(unsigned long long*)insn);
+ }
+
+ if (insn->code != (BPF_LD | BPF_IMM | BPF_DW)) {
+ ALOGE("Dumping all instructions till ins %d", insnIndex);
+ ALOGE("invalid relo for insn %d: code 0x%x", insnIndex, insn->code);
+ dumpIns((char*)insnsPtr, (insnIndex + 3) * 8);
+ return;
+ }
+
+ insn->imm = fd;
+ insn->src_reg = BPF_PSEUDO_MAP_FD;
+}
+
+static void applyMapRelo(ifstream& elfFile, vector<unique_fd> &mapFds, vector<codeSection>& cs) {
+ vector<string> mapNames;
+
+ int ret = getSectionSymNames(elfFile, "maps", mapNames);
+ if (ret) return;
+
+ for (int k = 0; k != (int)cs.size(); k++) {
+ Elf64_Rel* rel = (Elf64_Rel*)(cs[k].rel_data.data());
+ int n_rel = cs[k].rel_data.size() / sizeof(*rel);
+
+ for (int i = 0; i < n_rel; i++) {
+ int symIndex = ELF64_R_SYM(rel[i].r_info);
+ string symName;
+
+ ret = getSymNameByIdx(elfFile, symIndex, symName);
+ if (ret) return;
+
+ /* Find the map fd and apply relo */
+ for (int j = 0; j < (int)mapNames.size(); j++) {
+ if (!mapNames[j].compare(symName)) {
+ applyRelo(cs[k].data.data(), rel[i].r_offset, mapFds[j]);
+ break;
+ }
+ }
+ }
+ }
+}
+
+static int loadCodeSections(const char* elfPath, vector<codeSection>& cs, const string& license,
+ const char* prefix, const unsigned long long allowedDomainBitmask) {
+ unsigned kvers = kernelVersion();
+
+ if (!kvers) {
+ ALOGE("unable to get kernel version");
+ return -EINVAL;
+ }
+
+ string objName = pathToObjName(string(elfPath));
+
+ for (int i = 0; i < (int)cs.size(); i++) {
+ unique_fd& fd = cs[i].prog_fd;
+ int ret;
+ string name = cs[i].name;
+
+ if (!cs[i].prog_def.has_value()) {
+ ALOGE("[%d] '%s' missing program definition! bad bpf.o build?", i, name.c_str());
+ return -EINVAL;
+ }
+
+ unsigned min_kver = cs[i].prog_def->min_kver;
+ unsigned max_kver = cs[i].prog_def->max_kver;
+ ALOGD("cs[%d].name:%s min_kver:%x .max_kver:%x (kvers:%x)", i, name.c_str(), min_kver,
+ max_kver, kvers);
+ if (kvers < min_kver) continue;
+ if (kvers >= max_kver) continue;
+
+ domain selinux_context = getDomainFromSelinuxContext(cs[i].prog_def->selinux_context);
+ domain pin_subdir = getDomainFromPinSubdir(cs[i].prog_def->pin_subdir);
+
+ if (unrecognized(pin_subdir)) return -ENOTDIR;
+
+ if (specified(selinux_context)) {
+ if (!inDomainBitmask(selinux_context, allowedDomainBitmask)) {
+ ALOGE("prog %s has invalid selinux_context of %d (allowed bitmask 0x%llx)",
+ name.c_str(), selinux_context, allowedDomainBitmask);
+ return -EINVAL;
+ }
+ ALOGI("prog %s selinux_context [%-32s] -> %d -> '%s' (%s)", name.c_str(),
+ cs[i].prog_def->selinux_context, selinux_context,
+ lookupSelinuxContext(selinux_context), lookupPinSubdir(selinux_context));
+ }
+
+ if (specified(pin_subdir)) {
+ if (!inDomainBitmask(pin_subdir, allowedDomainBitmask)) {
+ ALOGE("prog %s has invalid pin_subdir of %d (allowed bitmask 0x%llx)", name.c_str(),
+ pin_subdir, allowedDomainBitmask);
+ return -EINVAL;
+ }
+ ALOGI("prog %s pin_subdir [%-32s] -> %d -> '%s'", name.c_str(),
+ cs[i].prog_def->pin_subdir, pin_subdir, lookupPinSubdir(pin_subdir));
+ }
+
+ // strip any potential $foo suffix
+ // this can be used to provide duplicate programs
+ // conditionally loaded based on running kernel version
+ name = name.substr(0, name.find_last_of('$'));
+
+ bool reuse = false;
+ // Format of pin location is
+ // /sys/fs/bpf/<prefix>prog_<objName>_<progName>
+ string progPinLoc = string(BPF_FS_PATH) + lookupPinSubdir(pin_subdir, prefix) + "prog_" +
+ objName + '_' + string(name);
+ if (access(progPinLoc.c_str(), F_OK) == 0) {
+ fd.reset(retrieveProgram(progPinLoc.c_str()));
+ ALOGD("New bpf prog load reusing prog %s, ret: %d (%s)", progPinLoc.c_str(), fd.get(),
+ (!fd.ok() ? std::strerror(errno) : "no error"));
+ reuse = true;
+ } else {
+ vector<char> log_buf(BPF_LOAD_LOG_SZ, 0);
+
+ union bpf_attr req = {
+ .prog_type = cs[i].type,
+ .kern_version = kvers,
+ .license = ptr_to_u64(license.c_str()),
+ .insns = ptr_to_u64(cs[i].data.data()),
+ .insn_cnt = static_cast<__u32>(cs[i].data.size() / sizeof(struct bpf_insn)),
+ .log_level = 1,
+ .log_buf = ptr_to_u64(log_buf.data()),
+ .log_size = static_cast<__u32>(log_buf.size()),
+ .expected_attach_type = cs[i].expected_attach_type,
+ };
+ strlcpy(req.prog_name, cs[i].name.c_str(), sizeof(req.prog_name));
+ fd.reset(bpf(BPF_PROG_LOAD, req));
+
+ ALOGD("BPF_PROG_LOAD call for %s (%s) returned fd: %d (%s)", elfPath,
+ cs[i].name.c_str(), fd.get(), (!fd.ok() ? std::strerror(errno) : "no error"));
+
+ if (!fd.ok()) {
+ vector<string> lines = android::base::Split(log_buf.data(), "\n");
+
+ ALOGW("BPF_PROG_LOAD - BEGIN log_buf contents:");
+ for (const auto& line : lines) ALOGW("%s", line.c_str());
+ ALOGW("BPF_PROG_LOAD - END log_buf contents.");
+
+ if (cs[i].prog_def->optional) {
+ ALOGW("failed program is marked optional - continuing...");
+ continue;
+ }
+ ALOGE("non-optional program failed to load.");
+ }
+ }
+
+ if (!fd.ok()) return fd.get();
+
+ if (!reuse) {
+ if (specified(selinux_context)) {
+ string createLoc = string(BPF_FS_PATH) + lookupPinSubdir(selinux_context) +
+ "tmp_prog_" + objName + '_' + string(name);
+ ret = bpfFdPin(fd, createLoc.c_str());
+ if (ret) {
+ int err = errno;
+ ALOGE("create %s -> %d [%d:%s]", createLoc.c_str(), ret, err, strerror(err));
+ return -err;
+ }
+ ret = renameat2(AT_FDCWD, createLoc.c_str(),
+ AT_FDCWD, progPinLoc.c_str(), RENAME_NOREPLACE);
+ if (ret) {
+ int err = errno;
+ ALOGE("rename %s %s -> %d [%d:%s]", createLoc.c_str(), progPinLoc.c_str(), ret,
+ err, strerror(err));
+ return -err;
+ }
+ } else {
+ ret = bpfFdPin(fd, progPinLoc.c_str());
+ if (ret) {
+ int err = errno;
+ ALOGE("create %s -> %d [%d:%s]", progPinLoc.c_str(), ret, err, strerror(err));
+ return -err;
+ }
+ }
+ if (chmod(progPinLoc.c_str(), 0440)) {
+ int err = errno;
+ ALOGE("chmod %s 0440 -> [%d:%s]", progPinLoc.c_str(), err, strerror(err));
+ return -err;
+ }
+ if (chown(progPinLoc.c_str(), (uid_t)cs[i].prog_def->uid,
+ (gid_t)cs[i].prog_def->gid)) {
+ int err = errno;
+ ALOGE("chown %s %d %d -> [%d:%s]", progPinLoc.c_str(), cs[i].prog_def->uid,
+ cs[i].prog_def->gid, err, strerror(err));
+ return -err;
+ }
+ }
+
+ int progId = bpfGetFdProgId(fd);
+ if (progId == -1) {
+ ALOGE("bpfGetFdProgId failed, ret: %d [%d]", progId, errno);
+ } else {
+ ALOGI("prog %s id %d", progPinLoc.c_str(), progId);
+ }
+ }
+
+ return 0;
+}
+
+int loadProg(const char* elfPath, bool* isCritical, const Location& location) {
+ vector<char> license;
+ vector<char> critical;
+ vector<codeSection> cs;
+ vector<unique_fd> mapFds;
+ int ret;
+
+ if (!isCritical) return -1;
+ *isCritical = false;
+
+ ifstream elfFile(elfPath, ios::in | ios::binary);
+ if (!elfFile.is_open()) return -1;
+
+ ret = readSectionByName("critical", elfFile, critical);
+ *isCritical = !ret;
+
+ ret = readSectionByName("license", elfFile, license);
+ if (ret) {
+ ALOGE("Couldn't find license in %s", elfPath);
+ return ret;
+ } else {
+ ALOGD("Loading %s%s ELF object %s with license %s",
+ *isCritical ? "critical for " : "optional", *isCritical ? (char*)critical.data() : "",
+ elfPath, (char*)license.data());
+ }
+
+ ALOGI("Platform BpfLoader processing ELF object %s", elfPath);
+
+ ret = readCodeSections(elfFile, cs, location.allowedProgTypes, location.allowedProgTypesLength);
+ if (ret) {
+ ALOGE("Couldn't read all code sections in %s", elfPath);
+ return ret;
+ }
+
+ /* Just for future debugging */
+ if (0) dumpAllCs(cs);
+
+ ret = createMaps(elfPath, elfFile, mapFds, location.prefix, location.allowedDomainBitmask);
+ if (ret) {
+ ALOGE("Failed to create maps: (ret=%d) in %s", ret, elfPath);
+ return ret;
+ }
+
+ for (int i = 0; i < (int)mapFds.size(); i++)
+ ALOGD("map_fd found at %d is %d in %s", i, mapFds[i].get(), elfPath);
+
+ applyMapRelo(elfFile, mapFds, cs);
+
+ ret = loadCodeSections(elfPath, cs, string(license.data()), location.prefix,
+ location.allowedDomainBitmask);
+ if (ret) ALOGE("Failed to load programs, loadCodeSections ret=%d", ret);
+
+ return ret;
+}
+
+} // namespace bpf
+} // namespace android
diff --git a/loader/include/libbpf_android.h b/loader/include/libbpf_android.h
new file mode 100644
index 0000000..172a2db
--- /dev/null
+++ b/loader/include/libbpf_android.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * Android BPF library - public API
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <linux/bpf.h>
+
+#include <fstream>
+
+namespace android {
+namespace bpf {
+
+// Bpf programs may specify per-program & per-map selinux_context and pin_subdir.
+//
+// The BpfLoader needs to convert these bpf.o specified strings into an enum
+// for internal use (to check that valid values were specified for the specific
+// location of the bpf.o file).
+//
+// It also needs to map selinux_context's into pin_subdir's.
+// This is because of how selinux_context is actually implemented via pin+rename.
+//
+// Thus 'domain' enumerates all selinux_context's/pin_subdir's that the BpfLoader
+// is aware of. Thus there currently needs to be a 1:1 mapping between the two.
+//
+enum class domain : int {
+ unrecognized = -1, // invalid for this version of the bpfloader
+ unspecified = 0, // means just use the default for that specific pin location
+ platform, // fs_bpf /sys/fs/bpf
+ vendor, // (T+) fs_bpf_vendor /sys/fs/bpf/vendor
+ loader, // (U+) fs_bpf_loader /sys/fs/bpf/loader
+};
+
+// Note: this does not include domain::unrecognized, but does include domain::unspecified
+static constexpr domain AllDomains[] = {
+ domain::unspecified,
+ domain::platform,
+ domain::vendor,
+ domain::loader,
+};
+
+static constexpr bool unrecognized(domain d) {
+ return d == domain::unrecognized;
+}
+
+// Note: this doesn't handle unrecognized, handle it first.
+static constexpr bool specified(domain d) {
+ return d != domain::unspecified;
+}
+
+static constexpr unsigned long long domainToBitmask(domain d) {
+ return specified(d) ? 1uLL << (static_cast<int>(d) - 1) : 0;
+}
+
+static constexpr bool inDomainBitmask(domain d, unsigned long long v) {
+ return domainToBitmask(d) & v;
+}
+
+struct Location {
+ const char* const dir = "";
+ const char* const prefix = "";
+ unsigned long long allowedDomainBitmask = 0;
+ const bpf_prog_type* allowedProgTypes = nullptr;
+ size_t allowedProgTypesLength = 0;
+};
+
+// BPF loader implementation. Loads an eBPF ELF object
+int loadProg(const char* elfPath, bool* isCritical, const Location &location = {});
+
+// Exposed for testing
+unsigned int readSectionUint(const char* name, std::ifstream& elfFile, unsigned int defVal);
+
+} // namespace bpf
+} // namespace android