|  | /* | 
|  | * Copyright (C) 2018-2023 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 "NetBpfLoader" | 
|  |  | 
|  | #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 "loader.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 { | 
|  |  | 
|  | const std::string& getBuildType() { | 
|  | static std::string t = android::base::GetProperty("ro.build.type", "unknown"); | 
|  | return t; | 
|  | } | 
|  |  | 
|  | 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::tethering:     return "fs_bpf_tethering"; | 
|  | case domain::net_private:   return "fs_bpf_net_private"; | 
|  | case domain::net_shared:    return "fs_bpf_net_shared"; | 
|  | case domain::netd_readonly: return "fs_bpf_netd_readonly"; | 
|  | case domain::netd_shared:   return "fs_bpf_netd_shared"; | 
|  | 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::tethering:     return "tethering/"; | 
|  | case domain::net_private:   return "net_private/"; | 
|  | case domain::net_shared:    return "net_shared/"; | 
|  | case domain::netd_readonly: return "netd_readonly/"; | 
|  | case domain::netd_shared:   return "netd_shared/"; | 
|  | 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. | 
|  | * | 
|  | * Programs shipped inside the tethering apex should be limited to networking stuff, | 
|  | * as KPROBE, PERF_EVENT, TRACEPOINT are dangerous to use from mainline updatable code, | 
|  | * since they are less stable abi/api and may conflict with platform uses of bpf. | 
|  | */ | 
|  | sectionType sectionNameTypes[] = { | 
|  | {"bind4/",         BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND}, | 
|  | {"bind6/",         BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND}, | 
|  | {"cgroupskb/",     BPF_PROG_TYPE_CGROUP_SKB,       BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"cgroupsock/",    BPF_PROG_TYPE_CGROUP_SOCK,      BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"connect4/",      BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT}, | 
|  | {"connect6/",      BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT}, | 
|  | {"egress/",        BPF_PROG_TYPE_CGROUP_SKB,       BPF_CGROUP_INET_EGRESS}, | 
|  | {"getsockopt/",    BPF_PROG_TYPE_CGROUP_SOCKOPT,   BPF_CGROUP_GETSOCKOPT}, | 
|  | {"ingress/",       BPF_PROG_TYPE_CGROUP_SKB,       BPF_CGROUP_INET_INGRESS}, | 
|  | {"lwt_in/",        BPF_PROG_TYPE_LWT_IN,           BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"lwt_out/",       BPF_PROG_TYPE_LWT_OUT,          BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"lwt_seg6local/", BPF_PROG_TYPE_LWT_SEG6LOCAL,    BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"lwt_xmit/",      BPF_PROG_TYPE_LWT_XMIT,         BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"postbind4/",     BPF_PROG_TYPE_CGROUP_SOCK,      BPF_CGROUP_INET4_POST_BIND}, | 
|  | {"postbind6/",     BPF_PROG_TYPE_CGROUP_SOCK,      BPF_CGROUP_INET6_POST_BIND}, | 
|  | {"recvmsg4/",      BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG}, | 
|  | {"recvmsg6/",      BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG}, | 
|  | {"schedact/",      BPF_PROG_TYPE_SCHED_ACT,        BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"schedcls/",      BPF_PROG_TYPE_SCHED_CLS,        BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"sendmsg4/",      BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG}, | 
|  | {"sendmsg6/",      BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG}, | 
|  | {"setsockopt/",    BPF_PROG_TYPE_CGROUP_SOCKOPT,   BPF_CGROUP_SETSOCKOPT}, | 
|  | {"skfilter/",      BPF_PROG_TYPE_SOCKET_FILTER,    BPF_ATTACH_TYPE_UNSPEC}, | 
|  | {"sockops/",       BPF_PROG_TYPE_SOCK_OPS,         BPF_CGROUP_SOCK_OPS}, | 
|  | {"sysctl",         BPF_PROG_TYPE_CGROUP_SYSCTL,    BPF_CGROUP_SYSCTL}, | 
|  | {"xdp/",           BPF_PROG_TYPE_XDP,              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 getSectionType(string& name) { | 
|  | for (auto& snt : sectionNameTypes) | 
|  | if (StartsWith(name, snt.name)) return snt.type; | 
|  |  | 
|  | 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, | 
|  | size_t sizeOfBpfProgDef) { | 
|  | vector<char> pdData; | 
|  | int ret = readSectionByName("progs", elfFile, pdData); | 
|  | if (ret) return ret; | 
|  |  | 
|  | if (pdData.size() % sizeOfBpfProgDef) { | 
|  | ALOGE("readProgDefs failed due to improper sized progs section, %zu %% %zu != 0", | 
|  | pdData.size(), sizeOfBpfProgDef); | 
|  | return -1; | 
|  | }; | 
|  |  | 
|  | int progCount = pdData.size() / sizeOfBpfProgDef; | 
|  | pd.resize(progCount); | 
|  | size_t trimmedSize = std::min(sizeOfBpfProgDef, sizeof(struct bpf_prog_def)); | 
|  |  | 
|  | const char* dataPtr = pdData.data(); | 
|  | for (auto& p : pd) { | 
|  | // First we zero initialize | 
|  | memset(&p, 0, sizeof(p)); | 
|  | // Then we set non-zero defaults | 
|  | p.bpfloader_max_ver = DEFAULT_BPFLOADER_MAX_VER;  // v1.0 | 
|  | // Then we copy over the structure prefix from the ELF file. | 
|  | memcpy(&p, dataPtr, trimmedSize); | 
|  | // Move to next struct in the ELF file | 
|  | dataPtr += sizeOfBpfProgDef; | 
|  | } | 
|  | 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; | 
|  | } | 
|  |  | 
|  | /* Read a section by its index - for ex to get sec hdr strtab blob */ | 
|  | static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs, size_t sizeOfBpfProgDef) { | 
|  | 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, sizeOfBpfProgDef); | 
|  | 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; | 
|  |  | 
|  | // 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) { | 
|  | // bpfGetFd... family of functions require at minimum a 4.14 kernel, | 
|  | // so on 4.9-T kernels just pretend the map matches our expectations. | 
|  | // Additionally we'll get almost equivalent test coverage on newer devices/kernels. | 
|  | // This is because the primary failure mode we're trying to detect here | 
|  | // is either a source code misconfiguration (which is likely kernel independent) | 
|  | // or a newly introduced kernel feature/bug (which is unlikely to get backported to 4.9). | 
|  | if (!isAtLeastKernelVersion(4, 14, 0)) return true; | 
|  |  | 
|  | // 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 size_t sizeOfBpfMapDef, | 
|  | const unsigned int bpfloader_ver) { | 
|  | 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() % sizeOfBpfMapDef) { | 
|  | ALOGE("createMaps failed due to improper sized maps section, %zu %% %zu != 0", | 
|  | mdData.size(), sizeOfBpfMapDef); | 
|  | return -1; | 
|  | }; | 
|  |  | 
|  | int mapCount = mdData.size() / sizeOfBpfMapDef; | 
|  | md.resize(mapCount); | 
|  | size_t trimmedSize = std::min(sizeOfBpfMapDef, sizeof(struct bpf_map_def)); | 
|  |  | 
|  | const char* dataPtr = mdData.data(); | 
|  | for (auto& m : md) { | 
|  | // First we zero initialize | 
|  | memset(&m, 0, sizeof(m)); | 
|  | // Then we set non-zero defaults | 
|  | m.bpfloader_max_ver = DEFAULT_BPFLOADER_MAX_VER;  // v1.0 | 
|  | m.max_kver = 0xFFFFFFFFu;                         // matches KVER_INF from bpf_helpers.h | 
|  | // Then we copy over the structure prefix from the ELF file. | 
|  | memcpy(&m, dataPtr, trimmedSize); | 
|  | // Move to next struct in the ELF file | 
|  | dataPtr += sizeOfBpfMapDef; | 
|  | } | 
|  |  | 
|  | 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 (bpfloader_ver < md[i].bpfloader_min_ver) { | 
|  | ALOGI("skipping map %s which requires bpfloader min ver 0x%05x", mapNames[i].c_str(), | 
|  | md[i].bpfloader_min_ver); | 
|  | mapFds.push_back(unique_fd()); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | if (bpfloader_ver >= md[i].bpfloader_max_ver) { | 
|  | ALOGI("skipping map %s which requires bpfloader max ver 0x%05x", mapNames[i].c_str(), | 
|  | md[i].bpfloader_max_ver); | 
|  | mapFds.push_back(unique_fd()); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | 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; | 
|  | } | 
|  |  | 
|  | if ((md[i].ignore_on_eng && isEng()) || (md[i].ignore_on_user && isUser()) || | 
|  | (md[i].ignore_on_userdebug && isUserdebug())) { | 
|  | ALOGI("skipping map %s which is ignored on %s builds", mapNames[i].c_str(), | 
|  | getBuildType().c_str()); | 
|  | mapFds.push_back(unique_fd()); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | if ((isArm() && isKernel32Bit() && md[i].ignore_on_arm32) || | 
|  | (isArm() && isKernel64Bit() && md[i].ignore_on_aarch64) || | 
|  | (isX86() && isKernel32Bit() && md[i].ignore_on_x86_32) || | 
|  | (isX86() && isKernel64Bit() && md[i].ignore_on_x86_64) || | 
|  | (isRiscV() && md[i].ignore_on_riscv64)) { | 
|  | ALOGI("skipping map %s which is ignored on %s", mapNames[i].c_str(), | 
|  | describeArch()); | 
|  | mapFds.push_back(unique_fd()); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | enum bpf_map_type type = md[i].type; | 
|  | if (type == BPF_MAP_TYPE_DEVMAP && !isAtLeastKernelVersion(4, 14, 0)) { | 
|  | // On Linux Kernels older than 4.14 this map type doesn't exist, but it can kind | 
|  | // of be approximated: ARRAY has the same userspace api, though it is not usable | 
|  | // by the same ebpf programs.  However, that's okay because the bpf_redirect_map() | 
|  | // helper doesn't exist on 4.9-T anyway (so the bpf program would fail to load, | 
|  | // and thus needs to be tagged as 4.14+ either way), so there's nothing useful you | 
|  | // could do with a DEVMAP anyway (that isn't already provided by an ARRAY)... | 
|  | // Hence using an ARRAY instead of a DEVMAP simply makes life easier for userspace. | 
|  | type = BPF_MAP_TYPE_ARRAY; | 
|  | } | 
|  | 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)) { | 
|  | 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)) { | 
|  | 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, | 
|  | }; | 
|  | if (isAtLeastKernelVersion(4, 14, 0)) | 
|  | 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 int bpfloader_ver) { | 
|  | 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; | 
|  |  | 
|  | unsigned bpfMinVer = cs[i].prog_def->bpfloader_min_ver; | 
|  | unsigned bpfMaxVer = cs[i].prog_def->bpfloader_max_ver; | 
|  | domain selinux_context = getDomainFromSelinuxContext(cs[i].prog_def->selinux_context); | 
|  | domain pin_subdir = getDomainFromPinSubdir(cs[i].prog_def->pin_subdir); | 
|  | // Note: make sure to only check for unrecognized *after* verifying bpfloader | 
|  | // version limits include this bpfloader's version. | 
|  |  | 
|  | ALOGD("cs[%d].name:%s requires bpfloader version [0x%05x,0x%05x)", i, name.c_str(), | 
|  | bpfMinVer, bpfMaxVer); | 
|  | if (bpfloader_ver < bpfMinVer) continue; | 
|  | if (bpfloader_ver >= bpfMaxVer) continue; | 
|  |  | 
|  | if ((cs[i].prog_def->ignore_on_eng && isEng()) || | 
|  | (cs[i].prog_def->ignore_on_user && isUser()) || | 
|  | (cs[i].prog_def->ignore_on_userdebug && isUserdebug())) { | 
|  | ALOGD("cs[%d].name:%s is ignored on %s builds", i, name.c_str(), | 
|  | getBuildType().c_str()); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | if ((isArm() && isKernel32Bit() && cs[i].prog_def->ignore_on_arm32) || | 
|  | (isArm() && isKernel64Bit() && cs[i].prog_def->ignore_on_aarch64) || | 
|  | (isX86() && isKernel32Bit() && cs[i].prog_def->ignore_on_x86_32) || | 
|  | (isX86() && isKernel64Bit() && cs[i].prog_def->ignore_on_x86_64) || | 
|  | (isRiscV() && cs[i].prog_def->ignore_on_riscv64)) { | 
|  | ALOGD("cs[%d].name:%s is ignored on %s", i, name.c_str(), describeArch()); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | if (unrecognized(pin_subdir)) return -ENOTDIR; | 
|  |  | 
|  | if (specified(selinux_context)) { | 
|  | 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)) { | 
|  | 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, | 
|  | }; | 
|  | if (isAtLeastKernelVersion(4, 14, 0)) | 
|  | 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* const elfPath, bool* const isCritical, const unsigned int bpfloader_ver, | 
|  | 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()); | 
|  | } | 
|  |  | 
|  | // the following default values are for bpfloader V0.0 format which does not include them | 
|  | unsigned int bpfLoaderMinVer = | 
|  | readSectionUint("bpfloader_min_ver", elfFile, DEFAULT_BPFLOADER_MIN_VER); | 
|  | unsigned int bpfLoaderMaxVer = | 
|  | readSectionUint("bpfloader_max_ver", elfFile, DEFAULT_BPFLOADER_MAX_VER); | 
|  | unsigned int bpfLoaderMinRequiredVer = | 
|  | readSectionUint("bpfloader_min_required_ver", elfFile, 0); | 
|  | size_t sizeOfBpfMapDef = | 
|  | readSectionUint("size_of_bpf_map_def", elfFile, DEFAULT_SIZEOF_BPF_MAP_DEF); | 
|  | size_t sizeOfBpfProgDef = | 
|  | readSectionUint("size_of_bpf_prog_def", elfFile, DEFAULT_SIZEOF_BPF_PROG_DEF); | 
|  |  | 
|  | // inclusive lower bound check | 
|  | if (bpfloader_ver < bpfLoaderMinVer) { | 
|  | ALOGI("BpfLoader version 0x%05x ignoring ELF object %s with min ver 0x%05x", | 
|  | bpfloader_ver, elfPath, bpfLoaderMinVer); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | // exclusive upper bound check | 
|  | if (bpfloader_ver >= bpfLoaderMaxVer) { | 
|  | ALOGI("BpfLoader version 0x%05x ignoring ELF object %s with max ver 0x%05x", | 
|  | bpfloader_ver, elfPath, bpfLoaderMaxVer); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | if (bpfloader_ver < bpfLoaderMinRequiredVer) { | 
|  | ALOGI("BpfLoader version 0x%05x failing due to ELF object %s with required min ver 0x%05x", | 
|  | bpfloader_ver, elfPath, bpfLoaderMinRequiredVer); | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | ALOGI("BpfLoader version 0x%05x processing ELF object %s with ver [0x%05x,0x%05x)", | 
|  | bpfloader_ver, elfPath, bpfLoaderMinVer, bpfLoaderMaxVer); | 
|  |  | 
|  | if (sizeOfBpfMapDef < DEFAULT_SIZEOF_BPF_MAP_DEF) { | 
|  | ALOGE("sizeof(bpf_map_def) of %zu is too small (< %d)", sizeOfBpfMapDef, | 
|  | DEFAULT_SIZEOF_BPF_MAP_DEF); | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | if (sizeOfBpfProgDef < DEFAULT_SIZEOF_BPF_PROG_DEF) { | 
|  | ALOGE("sizeof(bpf_prog_def) of %zu is too small (< %d)", sizeOfBpfProgDef, | 
|  | DEFAULT_SIZEOF_BPF_PROG_DEF); | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | ret = readCodeSections(elfFile, cs, sizeOfBpfProgDef); | 
|  | 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, sizeOfBpfMapDef, bpfloader_ver); | 
|  | 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, bpfloader_ver); | 
|  | if (ret) ALOGE("Failed to load programs, loadCodeSections ret=%d", ret); | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | }  // namespace bpf | 
|  | }  // namespace android |