Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2018 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Maciej Żenczykowski | e2f2b82 | 2024-05-01 05:16:51 -0700 | [diff] [blame] | 17 | #define LOG_TAG "BpfLoader" |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 18 | |
| 19 | #include <errno.h> |
Maciej Żenczykowski | e15229f | 2023-04-17 07:16:33 +0000 | [diff] [blame] | 20 | #include <fcntl.h> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 21 | #include <linux/bpf.h> |
| 22 | #include <linux/elf.h> |
| 23 | #include <log/log.h> |
| 24 | #include <stdint.h> |
| 25 | #include <stdio.h> |
| 26 | #include <stdlib.h> |
| 27 | #include <string.h> |
Connor O'Brien | 35425e5 | 2022-01-18 21:41:16 -0800 | [diff] [blame] | 28 | #include <sysexits.h> |
Maciej Żenczykowski | 83f2977 | 2020-01-27 03:11:51 -0800 | [diff] [blame] | 29 | #include <sys/stat.h> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 30 | #include <sys/utsname.h> |
Connor O'Brien | 35425e5 | 2022-01-18 21:41:16 -0800 | [diff] [blame] | 31 | #include <sys/wait.h> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 32 | #include <unistd.h> |
| 33 | |
Maciej Żenczykowski | 300c51f | 2022-12-14 04:18:02 -0800 | [diff] [blame] | 34 | #include "BpfSyscallWrappers.h" |
Maciej Żenczykowski | 07375e2 | 2020-02-19 14:23:59 -0800 | [diff] [blame] | 35 | #include "bpf/BpfUtils.h" |
Ken Chen | d568947 | 2021-12-20 18:07:21 +0800 | [diff] [blame] | 36 | #include "bpf/bpf_map_def.h" |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 37 | #include "include/libbpf_android.h" |
| 38 | |
| 39 | #include <cstdlib> |
| 40 | #include <fstream> |
| 41 | #include <iostream> |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 42 | #include <optional> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 43 | #include <string> |
Connor O'Brien | 35425e5 | 2022-01-18 21:41:16 -0800 | [diff] [blame] | 44 | #include <unordered_map> |
Christopher Ferris | c151c67 | 2019-02-01 15:31:26 -0800 | [diff] [blame] | 45 | #include <vector> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 46 | |
Connor O'Brien | 35425e5 | 2022-01-18 21:41:16 -0800 | [diff] [blame] | 47 | #include <android-base/cmsg.h> |
| 48 | #include <android-base/file.h> |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 49 | #include <android-base/logging.h> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 50 | #include <android-base/strings.h> |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 51 | #include <android-base/unique_fd.h> |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 52 | |
| 53 | #define BPF_FS_PATH "/sys/fs/bpf/" |
| 54 | |
| 55 | // Size of the BPF log buffer for verifier logging |
Stephane Lee | eb61b73 | 2021-10-21 17:03:11 -0700 | [diff] [blame] | 56 | #define BPF_LOAD_LOG_SZ 0xfffff |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 57 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 58 | // Unspecified attach type is 0 which is BPF_CGROUP_INET_INGRESS. |
| 59 | #define BPF_ATTACH_TYPE_UNSPEC BPF_CGROUP_INET_INGRESS |
| 60 | |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 61 | using android::base::EndsWith; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 62 | using android::base::StartsWith; |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 63 | using android::base::unique_fd; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 64 | using std::ifstream; |
| 65 | using std::ios; |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 66 | using std::optional; |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 67 | using std::strerror; |
Christopher Ferris | c151c67 | 2019-02-01 15:31:26 -0800 | [diff] [blame] | 68 | using std::string; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 69 | using std::vector; |
| 70 | |
| 71 | namespace android { |
| 72 | namespace bpf { |
| 73 | |
Maciej Żenczykowski | 8a117a3 | 2023-06-16 08:18:49 +0000 | [diff] [blame] | 74 | static unsigned int page_size = static_cast<unsigned int>(getpagesize()); |
| 75 | |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 76 | static string pathToObjName(const string& path) { |
| 77 | // extract everything after the final slash, ie. this is the filename 'foo@1.o' or 'bar.o' |
| 78 | string filename = android::base::Split(path, "/").back(); |
| 79 | // strip off everything from the final period onwards (strip '.o' suffix), ie. 'foo@1' or 'bar' |
| 80 | string name = filename.substr(0, filename.find_last_of('.')); |
| 81 | // strip any potential @1 suffix, this will leave us with just 'foo' or 'bar' |
| 82 | // this can be used to provide duplicate programs (mux based on the bpfloader version) |
| 83 | return name.substr(0, name.find_last_of('@')); |
Maciej Żenczykowski | f7c0d99 | 2021-01-21 16:01:04 -0800 | [diff] [blame] | 84 | } |
| 85 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 86 | typedef struct { |
| 87 | const char* name; |
| 88 | enum bpf_prog_type type; |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 89 | enum bpf_attach_type expected_attach_type; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 90 | } sectionType; |
| 91 | |
| 92 | /* |
| 93 | * Map section name prefixes to program types, the section name will be: |
Maciej Żenczykowski | 3adb1d5 | 2021-10-22 19:27:10 -0700 | [diff] [blame] | 94 | * SECTION(<prefix>/<name-of-program>) |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 95 | * For example: |
Maciej Żenczykowski | 3adb1d5 | 2021-10-22 19:27:10 -0700 | [diff] [blame] | 96 | * SECTION("tracepoint/sched_switch_func") where sched_switch_funcs |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 97 | * is the name of the program, and tracepoint is the type. |
Maciej Żenczykowski | 3adb1d5 | 2021-10-22 19:27:10 -0700 | [diff] [blame] | 98 | * |
| 99 | * However, be aware that you should not be directly using the SECTION() macro. |
| 100 | * Instead use the DEFINE_(BPF|XDP)_(PROG|MAP)... & LICENSE/CRITICAL macros. |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 101 | */ |
| 102 | sectionType sectionNameTypes[] = { |
Maciej Żenczykowski | e245fa9 | 2023-04-05 01:16:05 +0000 | [diff] [blame] | 103 | {"kprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC}, |
| 104 | {"kretprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC}, |
Maciej Żenczykowski | e245fa9 | 2023-04-05 01:16:05 +0000 | [diff] [blame] | 105 | {"perf_event/", BPF_PROG_TYPE_PERF_EVENT, BPF_ATTACH_TYPE_UNSPEC}, |
Maciej Żenczykowski | e245fa9 | 2023-04-05 01:16:05 +0000 | [diff] [blame] | 106 | {"skfilter/", BPF_PROG_TYPE_SOCKET_FILTER, BPF_ATTACH_TYPE_UNSPEC}, |
Maciej Żenczykowski | e245fa9 | 2023-04-05 01:16:05 +0000 | [diff] [blame] | 107 | {"tracepoint/", BPF_PROG_TYPE_TRACEPOINT, BPF_ATTACH_TYPE_UNSPEC}, |
| 108 | {"uprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC}, |
| 109 | {"uretprobe/", BPF_PROG_TYPE_KPROBE, BPF_ATTACH_TYPE_UNSPEC}, |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 110 | }; |
| 111 | |
| 112 | typedef struct { |
| 113 | enum bpf_prog_type type; |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 114 | enum bpf_attach_type expected_attach_type; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 115 | string name; |
| 116 | vector<char> data; |
| 117 | vector<char> rel_data; |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 118 | optional<struct bpf_prog_def> prog_def; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 119 | |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 120 | unique_fd prog_fd; /* fd after loading */ |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 121 | } codeSection; |
| 122 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 123 | static int readElfHeader(ifstream& elfFile, Elf64_Ehdr* eh) { |
| 124 | elfFile.seekg(0); |
| 125 | if (elfFile.fail()) return -1; |
| 126 | |
| 127 | if (!elfFile.read((char*)eh, sizeof(*eh))) return -1; |
| 128 | |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | /* Reads all section header tables into an Shdr array */ |
| 133 | static int readSectionHeadersAll(ifstream& elfFile, vector<Elf64_Shdr>& shTable) { |
| 134 | Elf64_Ehdr eh; |
| 135 | int ret = 0; |
| 136 | |
| 137 | ret = readElfHeader(elfFile, &eh); |
| 138 | if (ret) return ret; |
| 139 | |
| 140 | elfFile.seekg(eh.e_shoff); |
| 141 | if (elfFile.fail()) return -1; |
| 142 | |
| 143 | /* Read shdr table entries */ |
| 144 | shTable.resize(eh.e_shnum); |
| 145 | |
| 146 | if (!elfFile.read((char*)shTable.data(), (eh.e_shnum * eh.e_shentsize))) return -ENOMEM; |
| 147 | |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | /* Read a section by its index - for ex to get sec hdr strtab blob */ |
| 152 | static int readSectionByIdx(ifstream& elfFile, int id, vector<char>& sec) { |
| 153 | vector<Elf64_Shdr> shTable; |
Maciej Żenczykowski | d56ec05 | 2021-01-15 00:27:04 -0800 | [diff] [blame] | 154 | int ret = readSectionHeadersAll(elfFile, shTable); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 155 | if (ret) return ret; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 156 | |
| 157 | elfFile.seekg(shTable[id].sh_offset); |
| 158 | if (elfFile.fail()) return -1; |
| 159 | |
| 160 | sec.resize(shTable[id].sh_size); |
| 161 | if (!elfFile.read(sec.data(), shTable[id].sh_size)) return -1; |
| 162 | |
| 163 | return 0; |
| 164 | } |
| 165 | |
| 166 | /* Read whole section header string table */ |
| 167 | static int readSectionHeaderStrtab(ifstream& elfFile, vector<char>& strtab) { |
| 168 | Elf64_Ehdr eh; |
Maciej Żenczykowski | d56ec05 | 2021-01-15 00:27:04 -0800 | [diff] [blame] | 169 | int ret = readElfHeader(elfFile, &eh); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 170 | if (ret) return ret; |
| 171 | |
| 172 | ret = readSectionByIdx(elfFile, eh.e_shstrndx, strtab); |
| 173 | if (ret) return ret; |
| 174 | |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | /* Get name from offset in strtab */ |
| 179 | static int getSymName(ifstream& elfFile, int nameOff, string& name) { |
| 180 | int ret; |
| 181 | vector<char> secStrTab; |
| 182 | |
| 183 | ret = readSectionHeaderStrtab(elfFile, secStrTab); |
| 184 | if (ret) return ret; |
| 185 | |
| 186 | if (nameOff >= (int)secStrTab.size()) return -1; |
| 187 | |
| 188 | name = string((char*)secStrTab.data() + nameOff); |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | /* Reads a full section by name - example to get the GPL license */ |
| 193 | static int readSectionByName(const char* name, ifstream& elfFile, vector<char>& data) { |
| 194 | vector<char> secStrTab; |
| 195 | vector<Elf64_Shdr> shTable; |
| 196 | int ret; |
| 197 | |
| 198 | ret = readSectionHeadersAll(elfFile, shTable); |
| 199 | if (ret) return ret; |
| 200 | |
| 201 | ret = readSectionHeaderStrtab(elfFile, secStrTab); |
| 202 | if (ret) return ret; |
| 203 | |
| 204 | for (int i = 0; i < (int)shTable.size(); i++) { |
| 205 | char* secname = secStrTab.data() + shTable[i].sh_name; |
| 206 | if (!secname) continue; |
| 207 | |
| 208 | if (!strcmp(secname, name)) { |
| 209 | vector<char> dataTmp; |
| 210 | dataTmp.resize(shTable[i].sh_size); |
| 211 | |
| 212 | elfFile.seekg(shTable[i].sh_offset); |
| 213 | if (elfFile.fail()) return -1; |
| 214 | |
| 215 | if (!elfFile.read((char*)dataTmp.data(), shTable[i].sh_size)) return -1; |
| 216 | |
| 217 | data = dataTmp; |
| 218 | return 0; |
| 219 | } |
| 220 | } |
| 221 | return -2; |
| 222 | } |
| 223 | |
Maciej Żenczykowski | 7ed94ef | 2021-07-06 01:47:15 -0700 | [diff] [blame] | 224 | unsigned int readSectionUint(const char* name, ifstream& elfFile, unsigned int defVal) { |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 225 | vector<char> theBytes; |
| 226 | int ret = readSectionByName(name, elfFile, theBytes); |
| 227 | if (ret) { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 228 | ALOGV("Couldn't find section %s (defaulting to %u [0x%x]).", name, defVal, defVal); |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 229 | return defVal; |
| 230 | } else if (theBytes.size() < sizeof(unsigned int)) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 231 | ALOGE("Section %s too short (defaulting to %u [0x%x]).", name, defVal, defVal); |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 232 | return defVal; |
| 233 | } else { |
| 234 | // decode first 4 bytes as LE32 uint, there will likely be more bytes due to alignment. |
| 235 | unsigned int value = static_cast<unsigned char>(theBytes[3]); |
| 236 | value <<= 8; |
| 237 | value += static_cast<unsigned char>(theBytes[2]); |
| 238 | value <<= 8; |
| 239 | value += static_cast<unsigned char>(theBytes[1]); |
| 240 | value <<= 8; |
| 241 | value += static_cast<unsigned char>(theBytes[0]); |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 242 | ALOGV("Section %s value is %u [0x%x]", name, value, value); |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 243 | return value; |
| 244 | } |
| 245 | } |
| 246 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 247 | static int readSectionByType(ifstream& elfFile, int type, vector<char>& data) { |
| 248 | int ret; |
| 249 | vector<Elf64_Shdr> shTable; |
| 250 | |
| 251 | ret = readSectionHeadersAll(elfFile, shTable); |
| 252 | if (ret) return ret; |
| 253 | |
| 254 | for (int i = 0; i < (int)shTable.size(); i++) { |
| 255 | if ((int)shTable[i].sh_type != type) continue; |
| 256 | |
| 257 | vector<char> dataTmp; |
| 258 | dataTmp.resize(shTable[i].sh_size); |
| 259 | |
| 260 | elfFile.seekg(shTable[i].sh_offset); |
| 261 | if (elfFile.fail()) return -1; |
| 262 | |
| 263 | if (!elfFile.read((char*)dataTmp.data(), shTable[i].sh_size)) return -1; |
| 264 | |
| 265 | data = dataTmp; |
| 266 | return 0; |
| 267 | } |
| 268 | return -2; |
| 269 | } |
| 270 | |
| 271 | static bool symCompare(Elf64_Sym a, Elf64_Sym b) { |
| 272 | return (a.st_value < b.st_value); |
| 273 | } |
| 274 | |
| 275 | static int readSymTab(ifstream& elfFile, int sort, vector<Elf64_Sym>& data) { |
| 276 | int ret, numElems; |
| 277 | Elf64_Sym* buf; |
| 278 | vector<char> secData; |
| 279 | |
| 280 | ret = readSectionByType(elfFile, SHT_SYMTAB, secData); |
| 281 | if (ret) return ret; |
| 282 | |
| 283 | buf = (Elf64_Sym*)secData.data(); |
| 284 | numElems = (secData.size() / sizeof(Elf64_Sym)); |
| 285 | data.assign(buf, buf + numElems); |
| 286 | |
| 287 | if (sort) std::sort(data.begin(), data.end(), symCompare); |
| 288 | return 0; |
| 289 | } |
| 290 | |
Paul Lawrence | 7fb8b54 | 2022-07-19 16:13:49 -0700 | [diff] [blame] | 291 | static enum bpf_prog_type getFuseProgType() { |
| 292 | int result = BPF_PROG_TYPE_UNSPEC; |
| 293 | ifstream("/sys/fs/fuse/bpf_prog_type_fuse") >> result; |
| 294 | return static_cast<bpf_prog_type>(result); |
| 295 | } |
| 296 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 297 | static enum bpf_prog_type getSectionType(string& name) { |
Maciej Żenczykowski | 2b20313 | 2021-11-18 15:13:36 -0800 | [diff] [blame] | 298 | for (auto& snt : sectionNameTypes) |
| 299 | if (StartsWith(name, snt.name)) return snt.type; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 300 | |
Paul Lawrence | 9548f9f | 2021-11-09 16:32:43 +0000 | [diff] [blame] | 301 | // TODO Remove this code when fuse-bpf is upstream and this BPF_PROG_TYPE_FUSE is fixed |
Paul Lawrence | 7fb8b54 | 2022-07-19 16:13:49 -0700 | [diff] [blame] | 302 | if (StartsWith(name, "fuse/")) return getFuseProgType(); |
Paul Lawrence | 9548f9f | 2021-11-09 16:32:43 +0000 | [diff] [blame] | 303 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 304 | return BPF_PROG_TYPE_UNSPEC; |
| 305 | } |
| 306 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 307 | static enum bpf_attach_type getExpectedAttachType(string& name) { |
| 308 | for (auto& snt : sectionNameTypes) |
| 309 | if (StartsWith(name, snt.name)) return snt.expected_attach_type; |
| 310 | return BPF_ATTACH_TYPE_UNSPEC; |
| 311 | } |
| 312 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 313 | static string getSectionName(enum bpf_prog_type type) |
| 314 | { |
Maciej Żenczykowski | 2b20313 | 2021-11-18 15:13:36 -0800 | [diff] [blame] | 315 | for (auto& snt : sectionNameTypes) |
| 316 | if (snt.type == type) |
| 317 | return string(snt.name); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 318 | |
Steven Moreland | 0f10f3f | 2019-12-12 14:22:34 -0800 | [diff] [blame] | 319 | return "UNKNOWN SECTION NAME " + std::to_string(type); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 320 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 321 | |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 322 | static int readProgDefs(ifstream& elfFile, vector<struct bpf_prog_def>& pd) { |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 323 | vector<char> pdData; |
| 324 | int ret = readSectionByName("progs", elfFile, pdData); |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 325 | if (ret) return ret; |
| 326 | |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 327 | if (pdData.size() % sizeof(struct bpf_prog_def)) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 328 | ALOGE("readProgDefs failed due to improper sized progs section, %zu %% %zu != 0", |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 329 | pdData.size(), sizeof(struct bpf_prog_def)); |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 330 | return -1; |
| 331 | }; |
| 332 | |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 333 | pd.resize(pdData.size() / sizeof(struct bpf_prog_def)); |
| 334 | memcpy(pd.data(), pdData.data(), pdData.size()); |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 335 | return 0; |
| 336 | } |
| 337 | |
Connor O'Brien | 0ea4c6b | 2022-01-14 00:18:11 -0800 | [diff] [blame] | 338 | static int getSectionSymNames(ifstream& elfFile, const string& sectionName, vector<string>& names, |
| 339 | optional<unsigned> symbolType = std::nullopt) { |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 340 | int ret; |
| 341 | string name; |
| 342 | vector<Elf64_Sym> symtab; |
| 343 | vector<Elf64_Shdr> shTable; |
| 344 | |
| 345 | ret = readSymTab(elfFile, 1 /* sort */, symtab); |
| 346 | if (ret) return ret; |
| 347 | |
| 348 | /* Get index of section */ |
| 349 | ret = readSectionHeadersAll(elfFile, shTable); |
| 350 | if (ret) return ret; |
| 351 | |
| 352 | int sec_idx = -1; |
| 353 | for (int i = 0; i < (int)shTable.size(); i++) { |
| 354 | ret = getSymName(elfFile, shTable[i].sh_name, name); |
| 355 | if (ret) return ret; |
| 356 | |
| 357 | if (!name.compare(sectionName)) { |
| 358 | sec_idx = i; |
| 359 | break; |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | /* No section found with matching name*/ |
| 364 | if (sec_idx == -1) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 365 | ALOGW("No %s section could be found in elf object", sectionName.c_str()); |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 366 | return -1; |
| 367 | } |
| 368 | |
| 369 | for (int i = 0; i < (int)symtab.size(); i++) { |
Connor O'Brien | 0ea4c6b | 2022-01-14 00:18:11 -0800 | [diff] [blame] | 370 | if (symbolType.has_value() && ELF_ST_TYPE(symtab[i].st_info) != symbolType) continue; |
| 371 | |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 372 | if (symtab[i].st_shndx == sec_idx) { |
| 373 | string s; |
| 374 | ret = getSymName(elfFile, symtab[i].st_name, s); |
| 375 | if (ret) return ret; |
| 376 | names.push_back(s); |
| 377 | } |
| 378 | } |
| 379 | |
| 380 | return 0; |
| 381 | } |
| 382 | |
Steven Moreland | 0f10f3f | 2019-12-12 14:22:34 -0800 | [diff] [blame] | 383 | static bool IsAllowed(bpf_prog_type type, const bpf_prog_type* allowed, size_t numAllowed) { |
| 384 | if (allowed == nullptr) return true; |
| 385 | |
| 386 | for (size_t i = 0; i < numAllowed; i++) { |
Paul Lawrence | 7fb8b54 | 2022-07-19 16:13:49 -0700 | [diff] [blame] | 387 | if (allowed[i] == BPF_PROG_TYPE_UNSPEC) { |
| 388 | if (type == getFuseProgType()) return true; |
| 389 | } else if (type == allowed[i]) |
| 390 | return true; |
Steven Moreland | 0f10f3f | 2019-12-12 14:22:34 -0800 | [diff] [blame] | 391 | } |
| 392 | |
| 393 | return false; |
| 394 | } |
| 395 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 396 | /* Read a section by its index - for ex to get sec hdr strtab blob */ |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 397 | static int readCodeSections(ifstream& elfFile, vector<codeSection>& cs, |
Steven Moreland | 0f10f3f | 2019-12-12 14:22:34 -0800 | [diff] [blame] | 398 | const bpf_prog_type* allowed, size_t numAllowed) { |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 399 | vector<Elf64_Shdr> shTable; |
| 400 | int entries, ret = 0; |
| 401 | |
| 402 | ret = readSectionHeadersAll(elfFile, shTable); |
| 403 | if (ret) return ret; |
| 404 | entries = shTable.size(); |
| 405 | |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 406 | vector<struct bpf_prog_def> pd; |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 407 | ret = readProgDefs(elfFile, pd); |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 408 | if (ret) return ret; |
| 409 | vector<string> progDefNames; |
| 410 | ret = getSectionSymNames(elfFile, "progs", progDefNames); |
| 411 | if (!pd.empty() && ret) return ret; |
| 412 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 413 | for (int i = 0; i < entries; i++) { |
| 414 | string name; |
| 415 | codeSection cs_temp; |
| 416 | cs_temp.type = BPF_PROG_TYPE_UNSPEC; |
| 417 | |
| 418 | ret = getSymName(elfFile, shTable[i].sh_name, name); |
| 419 | if (ret) return ret; |
| 420 | |
| 421 | enum bpf_prog_type ptype = getSectionType(name); |
Steven Moreland | 0f10f3f | 2019-12-12 14:22:34 -0800 | [diff] [blame] | 422 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 423 | if (ptype == BPF_PROG_TYPE_UNSPEC) continue; |
Maciej Żenczykowski | f7c0d99 | 2021-01-21 16:01:04 -0800 | [diff] [blame] | 424 | |
Steven Moreland | 0f10f3f | 2019-12-12 14:22:34 -0800 | [diff] [blame] | 425 | if (!IsAllowed(ptype, allowed, numAllowed)) { |
| 426 | ALOGE("Program type %s not permitted here", getSectionName(ptype).c_str()); |
| 427 | return -1; |
| 428 | } |
| 429 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 430 | // This must be done before '/' is replaced with '_'. |
| 431 | cs_temp.expected_attach_type = getExpectedAttachType(name); |
Maciej Żenczykowski | f7c0d99 | 2021-01-21 16:01:04 -0800 | [diff] [blame] | 432 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 433 | string oldName = name; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 434 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 435 | // convert all slashes to underscores |
| 436 | std::replace(name.begin(), name.end(), '/', '_'); |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 437 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 438 | cs_temp.type = ptype; |
| 439 | cs_temp.name = name; |
| 440 | |
| 441 | ret = readSectionByIdx(elfFile, i, cs_temp.data); |
| 442 | if (ret) return ret; |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 443 | ALOGV("Loaded code section %d (%s)", i, name.c_str()); |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 444 | |
| 445 | vector<string> csSymNames; |
| 446 | ret = getSectionSymNames(elfFile, oldName, csSymNames, STT_FUNC); |
| 447 | if (ret || !csSymNames.size()) return ret; |
| 448 | for (size_t i = 0; i < progDefNames.size(); ++i) { |
| 449 | if (!progDefNames[i].compare(csSymNames[0] + "_def")) { |
| 450 | cs_temp.prog_def = pd[i]; |
| 451 | break; |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 452 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 453 | } |
| 454 | |
| 455 | /* Check for rel section */ |
| 456 | if (cs_temp.data.size() > 0 && i < entries) { |
| 457 | ret = getSymName(elfFile, shTable[i + 1].sh_name, name); |
| 458 | if (ret) return ret; |
| 459 | |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 460 | if (name == (".rel" + oldName)) { |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 461 | ret = readSectionByIdx(elfFile, i + 1, cs_temp.rel_data); |
| 462 | if (ret) return ret; |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 463 | ALOGV("Loaded relo section %d (%s)", i, name.c_str()); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 464 | } |
| 465 | } |
| 466 | |
| 467 | if (cs_temp.data.size() > 0) { |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 468 | cs.push_back(std::move(cs_temp)); |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 469 | ALOGV("Adding section %d to cs list", i); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 470 | } |
| 471 | } |
| 472 | return 0; |
| 473 | } |
| 474 | |
| 475 | static int getSymNameByIdx(ifstream& elfFile, int index, string& name) { |
| 476 | vector<Elf64_Sym> symtab; |
| 477 | int ret = 0; |
| 478 | |
| 479 | ret = readSymTab(elfFile, 0 /* !sort */, symtab); |
| 480 | if (ret) return ret; |
| 481 | |
| 482 | if (index >= (int)symtab.size()) return -1; |
| 483 | |
| 484 | return getSymName(elfFile, symtab[index].st_name, name); |
| 485 | } |
| 486 | |
Maciej Żenczykowski | 1a7fff3 | 2022-06-20 18:16:24 -0700 | [diff] [blame] | 487 | static bool mapMatchesExpectations(const unique_fd& fd, const string& mapName, |
| 488 | const struct bpf_map_def& mapDef, const enum bpf_map_type type) { |
Maciej Żenczykowski | 1a7fff3 | 2022-06-20 18:16:24 -0700 | [diff] [blame] | 489 | // Assuming fd is a valid Bpf Map file descriptor then |
| 490 | // all the following should always succeed on a 4.14+ kernel. |
| 491 | // If they somehow do fail, they'll return -1 (and set errno), |
| 492 | // which should then cause (among others) a key_size mismatch. |
Maciej Żenczykowski | 12bb520 | 2022-06-16 15:50:58 -0700 | [diff] [blame] | 493 | int fd_type = bpfGetFdMapType(fd); |
| 494 | int fd_key_size = bpfGetFdKeySize(fd); |
| 495 | int fd_value_size = bpfGetFdValueSize(fd); |
| 496 | int fd_max_entries = bpfGetFdMaxEntries(fd); |
| 497 | int fd_map_flags = bpfGetFdMapFlags(fd); |
| 498 | |
| 499 | // DEVMAPs are readonly from the bpf program side's point of view, as such |
| 500 | // the kernel in kernel/bpf/devmap.c dev_map_init_map() will set the flag |
| 501 | int desired_map_flags = (int)mapDef.map_flags; |
| 502 | if (type == BPF_MAP_TYPE_DEVMAP || type == BPF_MAP_TYPE_DEVMAP_HASH) |
| 503 | desired_map_flags |= BPF_F_RDONLY_PROG; |
| 504 | |
Maciej Żenczykowski | 28f01bb | 2023-06-20 19:40:22 +0000 | [diff] [blame] | 505 | // The .h file enforces that this is a power of two, and page size will |
| 506 | // also always be a power of two, so this logic is actually enough to |
| 507 | // force it to be a multiple of the page size, as required by the kernel. |
Maciej Żenczykowski | 8a117a3 | 2023-06-16 08:18:49 +0000 | [diff] [blame] | 508 | unsigned int desired_max_entries = mapDef.max_entries; |
| 509 | if (type == BPF_MAP_TYPE_RINGBUF) { |
| 510 | if (desired_max_entries < page_size) desired_max_entries = page_size; |
| 511 | } |
| 512 | |
Maciej Żenczykowski | 1a7fff3 | 2022-06-20 18:16:24 -0700 | [diff] [blame] | 513 | // The following checks should *never* trigger, if one of them somehow does, |
| 514 | // it probably means a bpf .o file has been changed/replaced at runtime |
| 515 | // and bpfloader was manually rerun (normally it should only run *once* |
| 516 | // early during the boot process). |
| 517 | // Another possibility is that something is misconfigured in the code: |
| 518 | // most likely a shared map is declared twice differently. |
| 519 | // But such a change should never be checked into the source tree... |
| 520 | if ((fd_type == type) && |
| 521 | (fd_key_size == (int)mapDef.key_size) && |
| 522 | (fd_value_size == (int)mapDef.value_size) && |
Maciej Żenczykowski | 8a117a3 | 2023-06-16 08:18:49 +0000 | [diff] [blame] | 523 | (fd_max_entries == (int)desired_max_entries) && |
Maciej Żenczykowski | 1a7fff3 | 2022-06-20 18:16:24 -0700 | [diff] [blame] | 524 | (fd_map_flags == desired_map_flags)) { |
| 525 | return true; |
| 526 | } |
Maciej Żenczykowski | 12bb520 | 2022-06-16 15:50:58 -0700 | [diff] [blame] | 527 | |
| 528 | ALOGE("bpf map name %s mismatch: desired/found: " |
| 529 | "type:%d/%d key:%u/%d value:%u/%d entries:%u/%d flags:%u/%d", |
| 530 | mapName.c_str(), type, fd_type, mapDef.key_size, fd_key_size, mapDef.value_size, |
| 531 | fd_value_size, mapDef.max_entries, fd_max_entries, desired_map_flags, fd_map_flags); |
| 532 | return false; |
| 533 | } |
| 534 | |
Maciej Żenczykowski | d8a4578 | 2021-01-14 23:36:32 -0800 | [diff] [blame] | 535 | static int createMaps(const char* elfPath, ifstream& elfFile, vector<unique_fd>& mapFds, |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 536 | const char* prefix) { |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 537 | int ret; |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 538 | vector<char> mdData; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 539 | vector<struct bpf_map_def> md; |
| 540 | vector<string> mapNames; |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 541 | string objName = pathToObjName(string(elfPath)); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 542 | |
| 543 | ret = readSectionByName("maps", elfFile, mdData); |
Steven Moreland | c0905b4 | 2019-12-12 14:21:20 -0800 | [diff] [blame] | 544 | if (ret == -2) return 0; // no maps to read |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 545 | if (ret) return ret; |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 546 | |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 547 | if (mdData.size() % sizeof(struct bpf_map_def)) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 548 | ALOGE("createMaps failed due to improper sized maps section, %zu %% %zu != 0", |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 549 | mdData.size(), sizeof(struct bpf_map_def)); |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 550 | return -1; |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 551 | } |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 552 | md.resize(mdData.size() / sizeof(struct bpf_map_def)); |
| 553 | memcpy(md.data(), mdData.data(), mdData.size()); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 554 | |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 555 | ret = getSectionSymNames(elfFile, "maps", mapNames); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 556 | if (ret) return ret; |
| 557 | |
Maciej Żenczykowski | bbab818 | 2022-06-22 22:51:07 -0700 | [diff] [blame] | 558 | unsigned kvers = kernelVersion(); |
| 559 | |
Maciej Żenczykowski | 36c53ba | 2021-07-05 15:20:34 -0700 | [diff] [blame] | 560 | for (int i = 0; i < (int)mapNames.size(); i++) { |
Maciej Żenczykowski | 2a5d016 | 2022-07-21 13:27:24 +0000 | [diff] [blame] | 561 | if (md[i].zero != 0) abort(); |
| 562 | |
Maciej Żenczykowski | 36c53ba | 2021-07-05 15:20:34 -0700 | [diff] [blame] | 563 | if (kvers < md[i].min_kver) { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 564 | ALOGD("skipping map %s which requires kernel version 0x%x >= 0x%x", |
Maciej Żenczykowski | 36c53ba | 2021-07-05 15:20:34 -0700 | [diff] [blame] | 565 | mapNames[i].c_str(), kvers, md[i].min_kver); |
| 566 | mapFds.push_back(unique_fd()); |
| 567 | continue; |
| 568 | } |
| 569 | |
| 570 | if (kvers >= md[i].max_kver) { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 571 | ALOGD("skipping map %s which requires kernel version 0x%x < 0x%x", |
Maciej Żenczykowski | 36c53ba | 2021-07-05 15:20:34 -0700 | [diff] [blame] | 572 | mapNames[i].c_str(), kvers, md[i].max_kver); |
| 573 | mapFds.push_back(unique_fd()); |
| 574 | continue; |
| 575 | } |
| 576 | |
Maciej Żenczykowski | 12bb520 | 2022-06-16 15:50:58 -0700 | [diff] [blame] | 577 | enum bpf_map_type type = md[i].type; |
Maciej Żenczykowski | 12bb520 | 2022-06-16 15:50:58 -0700 | [diff] [blame] | 578 | if (type == BPF_MAP_TYPE_DEVMAP_HASH && !isAtLeastKernelVersion(5, 4, 0)) { |
| 579 | // On Linux Kernels older than 5.4 this map type doesn't exist, but it can kind |
| 580 | // of be approximated: HASH has the same userspace visible api. |
| 581 | // However it cannot be used by ebpf programs in the same way. |
| 582 | // Since bpf_redirect_map() only requires 4.14, a program using a DEVMAP_HASH map |
| 583 | // would fail to load (due to trying to redirect to a HASH instead of DEVMAP_HASH). |
| 584 | // One must thus tag any BPF_MAP_TYPE_DEVMAP_HASH + bpf_redirect_map() using |
| 585 | // programs as being 5.4+... |
| 586 | type = BPF_MAP_TYPE_HASH; |
| 587 | } |
| 588 | |
Maciej Żenczykowski | 28f01bb | 2023-06-20 19:40:22 +0000 | [diff] [blame] | 589 | // The .h file enforces that this is a power of two, and page size will |
| 590 | // also always be a power of two, so this logic is actually enough to |
| 591 | // force it to be a multiple of the page size, as required by the kernel. |
Maciej Żenczykowski | 8a117a3 | 2023-06-16 08:18:49 +0000 | [diff] [blame] | 592 | unsigned int max_entries = md[i].max_entries; |
| 593 | if (type == BPF_MAP_TYPE_RINGBUF) { |
| 594 | if (max_entries < page_size) max_entries = page_size; |
| 595 | } |
| 596 | |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 597 | // Format of pin location is /sys/fs/bpf/<prefix>map_<objName>_<mapName> |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 598 | // except that maps shared across .o's have empty <objName> |
| 599 | // Note: <objName> refers to the extension-less basename of the .o file (without @ suffix). |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 600 | string mapPinLoc = string(BPF_FS_PATH) + prefix + "map_" + |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 601 | (md[i].shared ? "" : objName) + "_" + mapNames[i]; |
Maciej Żenczykowski | 36c53ba | 2021-07-05 15:20:34 -0700 | [diff] [blame] | 602 | bool reuse = false; |
| 603 | unique_fd fd; |
| 604 | int saved_errno; |
| 605 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 606 | if (access(mapPinLoc.c_str(), F_OK) == 0) { |
Maciej Żenczykowski | eb199dd | 2022-07-01 03:21:40 -0700 | [diff] [blame] | 607 | fd.reset(mapRetrieveRO(mapPinLoc.c_str())); |
Maciej Żenczykowski | 2c37213 | 2021-03-01 23:09:54 -0800 | [diff] [blame] | 608 | saved_errno = errno; |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 609 | ALOGV("bpf_create_map reusing map %s, ret: %d", mapNames[i].c_str(), fd.get()); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 610 | reuse = true; |
| 611 | } else { |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 612 | union bpf_attr req = { |
| 613 | .map_type = type, |
| 614 | .key_size = md[i].key_size, |
| 615 | .value_size = md[i].value_size, |
| 616 | .max_entries = max_entries, |
| 617 | .map_flags = md[i].map_flags, |
Connor O'Brien | 35425e5 | 2022-01-18 21:41:16 -0800 | [diff] [blame] | 618 | }; |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 619 | strlcpy(req.map_name, mapNames[i].c_str(), sizeof(req.map_name)); |
| 620 | fd.reset(bpf(BPF_MAP_CREATE, req)); |
Maciej Żenczykowski | 2c37213 | 2021-03-01 23:09:54 -0800 | [diff] [blame] | 621 | saved_errno = errno; |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 622 | ALOGV("bpf_create_map name %s, ret: %d", mapNames[i].c_str(), fd.get()); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 623 | } |
| 624 | |
Maciej Żenczykowski | 12bb520 | 2022-06-16 15:50:58 -0700 | [diff] [blame] | 625 | if (!fd.ok()) return -saved_errno; |
| 626 | |
| 627 | // When reusing a pinned map, we need to check the map type/sizes/etc match, but for |
| 628 | // safety (since reuse code path is rare) run these checks even if we just created it. |
| 629 | // We assume failure is due to pinned map mismatch, hence the 'NOT UNIQUE' return code. |
| 630 | if (!mapMatchesExpectations(fd, mapNames[i], md[i], type)) return -ENOTUNIQ; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 631 | |
| 632 | if (!reuse) { |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 633 | ret = bpfFdPin(fd, mapPinLoc.c_str()); |
| 634 | if (ret) { |
| 635 | int err = errno; |
| 636 | ALOGE("pin %s -> %d [%d:%s]", mapPinLoc.c_str(), ret, err, strerror(err)); |
| 637 | return -err; |
Maciej Żenczykowski | 4181713 | 2022-06-03 08:41:04 -0700 | [diff] [blame] | 638 | } |
Maciej Żenczykowski | 83f2977 | 2020-01-27 03:11:51 -0800 | [diff] [blame] | 639 | ret = chmod(mapPinLoc.c_str(), md[i].mode); |
Maciej Żenczykowski | 4181713 | 2022-06-03 08:41:04 -0700 | [diff] [blame] | 640 | if (ret) { |
| 641 | int err = errno; |
| 642 | ALOGE("chmod(%s, 0%o) = %d [%d:%s]", mapPinLoc.c_str(), md[i].mode, ret, err, |
| 643 | strerror(err)); |
| 644 | return -err; |
| 645 | } |
Maciej Żenczykowski | 5e4aabf | 2022-06-27 01:15:53 -0700 | [diff] [blame] | 646 | ret = chown(mapPinLoc.c_str(), (uid_t)md[i].uid, (gid_t)md[i].gid); |
| 647 | if (ret) { |
| 648 | int err = errno; |
| 649 | ALOGE("chown(%s, %u, %u) = %d [%d:%s]", mapPinLoc.c_str(), md[i].uid, md[i].gid, |
| 650 | ret, err, strerror(err)); |
| 651 | return -err; |
| 652 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 653 | } |
| 654 | |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 655 | int mapId = bpfGetFdMapId(fd); |
| 656 | if (mapId == -1) { |
| 657 | ALOGE("bpfGetFdMapId failed, ret: %d [%d]", mapId, errno); |
Maciej Żenczykowski | 57412c2 | 2022-05-20 16:44:06 -0700 | [diff] [blame] | 658 | } else { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 659 | ALOGD("map %s id %d", mapPinLoc.c_str(), mapId); |
Maciej Żenczykowski | 57412c2 | 2022-05-20 16:44:06 -0700 | [diff] [blame] | 660 | } |
| 661 | |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 662 | mapFds.push_back(std::move(fd)); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 663 | } |
| 664 | |
| 665 | return ret; |
| 666 | } |
| 667 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 668 | static void applyRelo(void* insnsPtr, Elf64_Addr offset, int fd) { |
| 669 | int insnIndex; |
| 670 | struct bpf_insn *insn, *insns; |
| 671 | |
| 672 | insns = (struct bpf_insn*)(insnsPtr); |
| 673 | |
| 674 | insnIndex = offset / sizeof(struct bpf_insn); |
| 675 | insn = &insns[insnIndex]; |
| 676 | |
Maciej Żenczykowski | 509b1b9 | 2023-03-07 01:11:20 +0000 | [diff] [blame] | 677 | // Occasionally might be useful for relocation debugging, but pretty spammy |
| 678 | if (0) { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 679 | ALOGV("applying relo to instruction at byte offset: %llu, " |
Maciej Żenczykowski | 509b1b9 | 2023-03-07 01:11:20 +0000 | [diff] [blame] | 680 | "insn offset %d, insn %llx", |
| 681 | (unsigned long long)offset, insnIndex, *(unsigned long long*)insn); |
| 682 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 683 | |
| 684 | if (insn->code != (BPF_LD | BPF_IMM | BPF_DW)) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 685 | ALOGE("invalid relo for insn %d: code 0x%x", insnIndex, insn->code); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 686 | return; |
| 687 | } |
| 688 | |
| 689 | insn->imm = fd; |
| 690 | insn->src_reg = BPF_PSEUDO_MAP_FD; |
| 691 | } |
| 692 | |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 693 | static void applyMapRelo(ifstream& elfFile, vector<unique_fd> &mapFds, vector<codeSection>& cs) { |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 694 | vector<string> mapNames; |
| 695 | |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 696 | int ret = getSectionSymNames(elfFile, "maps", mapNames); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 697 | if (ret) return; |
| 698 | |
| 699 | for (int k = 0; k != (int)cs.size(); k++) { |
| 700 | Elf64_Rel* rel = (Elf64_Rel*)(cs[k].rel_data.data()); |
| 701 | int n_rel = cs[k].rel_data.size() / sizeof(*rel); |
| 702 | |
| 703 | for (int i = 0; i < n_rel; i++) { |
| 704 | int symIndex = ELF64_R_SYM(rel[i].r_info); |
| 705 | string symName; |
| 706 | |
| 707 | ret = getSymNameByIdx(elfFile, symIndex, symName); |
| 708 | if (ret) return; |
| 709 | |
| 710 | /* Find the map fd and apply relo */ |
| 711 | for (int j = 0; j < (int)mapNames.size(); j++) { |
| 712 | if (!mapNames[j].compare(symName)) { |
| 713 | applyRelo(cs[k].data.data(), rel[i].r_offset, mapFds[j]); |
| 714 | break; |
| 715 | } |
| 716 | } |
| 717 | } |
| 718 | } |
| 719 | } |
| 720 | |
Maciej Żenczykowski | d8a4578 | 2021-01-14 23:36:32 -0800 | [diff] [blame] | 721 | static int loadCodeSections(const char* elfPath, vector<codeSection>& cs, const string& license, |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 722 | const char* prefix) { |
Maciej Żenczykowski | 07375e2 | 2020-02-19 14:23:59 -0800 | [diff] [blame] | 723 | unsigned kvers = kernelVersion(); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 724 | |
Maciej Żenczykowski | 5c79165 | 2022-08-03 23:49:08 +0000 | [diff] [blame] | 725 | if (!kvers) { |
| 726 | ALOGE("unable to get kernel version"); |
| 727 | return -EINVAL; |
| 728 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 729 | |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 730 | string objName = pathToObjName(string(elfPath)); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 731 | |
| 732 | for (int i = 0; i < (int)cs.size(); i++) { |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 733 | unique_fd& fd = cs[i].prog_fd; |
| 734 | int ret; |
Maciej Żenczykowski | 681f604 | 2020-04-21 15:34:18 -0700 | [diff] [blame] | 735 | string name = cs[i].name; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 736 | |
Maciej Żenczykowski | 5c79165 | 2022-08-03 23:49:08 +0000 | [diff] [blame] | 737 | if (!cs[i].prog_def.has_value()) { |
| 738 | ALOGE("[%d] '%s' missing program definition! bad bpf.o build?", i, name.c_str()); |
| 739 | return -EINVAL; |
Maciej Żenczykowski | 07375e2 | 2020-02-19 14:23:59 -0800 | [diff] [blame] | 740 | } |
| 741 | |
Maciej Żenczykowski | 5c79165 | 2022-08-03 23:49:08 +0000 | [diff] [blame] | 742 | unsigned min_kver = cs[i].prog_def->min_kver; |
| 743 | unsigned max_kver = cs[i].prog_def->max_kver; |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 744 | if (kvers < min_kver || kvers >= max_kver) { |
| 745 | ALOGD("skipping program cs[%d].name:%s min_kver:%x max_kver:%x (kvers:%x)", |
| 746 | i, name.c_str(), min_kver, max_kver, kvers); |
| 747 | continue; |
| 748 | } |
Maciej Żenczykowski | 5c79165 | 2022-08-03 23:49:08 +0000 | [diff] [blame] | 749 | |
Maciej Żenczykowski | 681f604 | 2020-04-21 15:34:18 -0700 | [diff] [blame] | 750 | // strip any potential $foo suffix |
| 751 | // this can be used to provide duplicate programs |
| 752 | // conditionally loaded based on running kernel version |
Maciej Żenczykowski | 428843d | 2020-04-23 12:43:44 -0700 | [diff] [blame] | 753 | name = name.substr(0, name.find_last_of('$')); |
Maciej Żenczykowski | 681f604 | 2020-04-21 15:34:18 -0700 | [diff] [blame] | 754 | |
| 755 | bool reuse = false; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 756 | // Format of pin location is |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 757 | // /sys/fs/bpf/<prefix>prog_<objName>_<progName> |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 758 | string progPinLoc = string(BPF_FS_PATH) + prefix + "prog_" + |
Maciej Żenczykowski | 21869ef | 2022-07-07 06:01:57 -0700 | [diff] [blame] | 759 | objName + '_' + string(name); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 760 | if (access(progPinLoc.c_str(), F_OK) == 0) { |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 761 | fd.reset(retrieveProgram(progPinLoc.c_str())); |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 762 | ALOGV("New bpf prog load reusing prog %s, ret: %d (%s)", progPinLoc.c_str(), fd.get(), |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 763 | (!fd.ok() ? std::strerror(errno) : "no error")); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 764 | reuse = true; |
| 765 | } else { |
| 766 | vector<char> log_buf(BPF_LOAD_LOG_SZ, 0); |
| 767 | |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 768 | union bpf_attr req = { |
| 769 | .prog_type = cs[i].type, |
| 770 | .kern_version = kvers, |
| 771 | .license = ptr_to_u64(license.c_str()), |
| 772 | .insns = ptr_to_u64(cs[i].data.data()), |
| 773 | .insn_cnt = static_cast<__u32>(cs[i].data.size() / sizeof(struct bpf_insn)), |
| 774 | .log_level = 1, |
| 775 | .log_buf = ptr_to_u64(log_buf.data()), |
| 776 | .log_size = static_cast<__u32>(log_buf.size()), |
| 777 | .expected_attach_type = cs[i].expected_attach_type, |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 778 | }; |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 779 | strlcpy(req.prog_name, cs[i].name.c_str(), sizeof(req.prog_name)); |
| 780 | fd.reset(bpf(BPF_PROG_LOAD, req)); |
Tyler Wear | 4e2f460 | 2022-02-03 09:46:01 -0800 | [diff] [blame] | 781 | |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 782 | if (!fd.ok()) { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 783 | ALOGW("BPF_PROG_LOAD call for %s (%s) returned fd: %d (%s)", elfPath, |
| 784 | cs[i].name.c_str(), fd.get(), std::strerror(errno)); |
| 785 | |
Maciej Żenczykowski | f7c0d99 | 2021-01-21 16:01:04 -0800 | [diff] [blame] | 786 | vector<string> lines = android::base::Split(log_buf.data(), "\n"); |
Maciej Żenczykowski | 524deef | 2020-02-11 11:12:37 -0800 | [diff] [blame] | 787 | |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 788 | ALOGW("BPF_PROG_LOAD - BEGIN log_buf contents:"); |
Maciej Żenczykowski | aa295c8 | 2020-06-16 17:02:48 -0700 | [diff] [blame] | 789 | for (const auto& line : lines) ALOGW("%s", line.c_str()); |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 790 | ALOGW("BPF_PROG_LOAD - END log_buf contents."); |
Maciej Żenczykowski | aa295c8 | 2020-06-16 17:02:48 -0700 | [diff] [blame] | 791 | |
Maciej Żenczykowski | 5c79165 | 2022-08-03 23:49:08 +0000 | [diff] [blame] | 792 | if (cs[i].prog_def->optional) { |
Maciej Żenczykowski | aa295c8 | 2020-06-16 17:02:48 -0700 | [diff] [blame] | 793 | ALOGW("failed program is marked optional - continuing..."); |
| 794 | continue; |
| 795 | } |
| 796 | ALOGE("non-optional program failed to load."); |
Maciej Żenczykowski | 524deef | 2020-02-11 11:12:37 -0800 | [diff] [blame] | 797 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 798 | } |
| 799 | |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 800 | if (!fd.ok()) return fd.get(); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 801 | |
| 802 | if (!reuse) { |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 803 | ret = bpfFdPin(fd, progPinLoc.c_str()); |
| 804 | if (ret) { |
| 805 | int err = errno; |
| 806 | ALOGE("create %s -> %d [%d:%s]", progPinLoc.c_str(), ret, err, strerror(err)); |
| 807 | return -err; |
Maciej Żenczykowski | 4181713 | 2022-06-03 08:41:04 -0700 | [diff] [blame] | 808 | } |
| 809 | if (chmod(progPinLoc.c_str(), 0440)) { |
| 810 | int err = errno; |
| 811 | ALOGE("chmod %s 0440 -> [%d:%s]", progPinLoc.c_str(), err, strerror(err)); |
| 812 | return -err; |
| 813 | } |
Maciej Żenczykowski | 5c79165 | 2022-08-03 23:49:08 +0000 | [diff] [blame] | 814 | if (chown(progPinLoc.c_str(), (uid_t)cs[i].prog_def->uid, |
| 815 | (gid_t)cs[i].prog_def->gid)) { |
| 816 | int err = errno; |
| 817 | ALOGE("chown %s %d %d -> [%d:%s]", progPinLoc.c_str(), cs[i].prog_def->uid, |
| 818 | cs[i].prog_def->gid, err, strerror(err)); |
| 819 | return -err; |
Connor O'Brien | 3278a16 | 2020-02-13 21:45:22 -0800 | [diff] [blame] | 820 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 821 | } |
| 822 | |
Maciej Żenczykowski | b44e287 | 2023-06-12 23:10:52 -0700 | [diff] [blame] | 823 | int progId = bpfGetFdProgId(fd); |
| 824 | if (progId == -1) { |
| 825 | ALOGE("bpfGetFdProgId failed, ret: %d [%d]", progId, errno); |
Maciej Żenczykowski | 57412c2 | 2022-05-20 16:44:06 -0700 | [diff] [blame] | 826 | } else { |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 827 | ALOGD("prog %s id %d", progPinLoc.c_str(), progId); |
Maciej Żenczykowski | 57412c2 | 2022-05-20 16:44:06 -0700 | [diff] [blame] | 828 | } |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 829 | } |
| 830 | |
| 831 | return 0; |
| 832 | } |
| 833 | |
Connor O'Brien | 6c0ce9f | 2022-12-01 20:08:17 -0800 | [diff] [blame] | 834 | int loadProg(const char* elfPath, bool* isCritical, const Location& location) { |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 835 | vector<char> license; |
Maciej Żenczykowski | 4ba8c1c | 2020-06-10 15:49:31 -0700 | [diff] [blame] | 836 | vector<char> critical; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 837 | vector<codeSection> cs; |
Connor O'Brien | 8d49fc7 | 2019-10-24 18:23:49 -0700 | [diff] [blame] | 838 | vector<unique_fd> mapFds; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 839 | int ret; |
| 840 | |
Maciej Żenczykowski | 89515d9 | 2020-06-14 19:27:33 -0700 | [diff] [blame] | 841 | if (!isCritical) return -1; |
| 842 | *isCritical = false; |
| 843 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 844 | ifstream elfFile(elfPath, ios::in | ios::binary); |
| 845 | if (!elfFile.is_open()) return -1; |
| 846 | |
Maciej Żenczykowski | 4ba8c1c | 2020-06-10 15:49:31 -0700 | [diff] [blame] | 847 | ret = readSectionByName("critical", elfFile, critical); |
Maciej Żenczykowski | 89515d9 | 2020-06-14 19:27:33 -0700 | [diff] [blame] | 848 | *isCritical = !ret; |
Maciej Żenczykowski | 4ba8c1c | 2020-06-10 15:49:31 -0700 | [diff] [blame] | 849 | |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 850 | ret = readSectionByName("license", elfFile, license); |
| 851 | if (ret) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 852 | ALOGE("Couldn't find license in %s", elfPath); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 853 | return ret; |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 854 | } |
| 855 | |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 856 | ALOGI("Platform BpfLoader loading %s%s ELF object %s with license %s", |
| 857 | *isCritical ? "critical for " : "optional", *isCritical ? (char*)critical.data() : "", |
| 858 | elfPath, (char*)license.data()); |
Maciej Żenczykowski | 9217eee | 2021-03-03 05:28:52 -0800 | [diff] [blame] | 859 | |
Maciej Żenczykowski | c82f566 | 2024-03-10 14:37:24 -0700 | [diff] [blame] | 860 | ret = readCodeSections(elfFile, cs, location.allowedProgTypes, location.allowedProgTypesLength); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 861 | if (ret) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 862 | ALOGE("Couldn't read all code sections in %s", elfPath); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 863 | return ret; |
| 864 | } |
| 865 | |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 866 | ret = createMaps(elfPath, elfFile, mapFds, location.prefix); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 867 | if (ret) { |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 868 | ALOGE("Failed to create maps: (ret=%d) in %s", ret, elfPath); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 869 | return ret; |
| 870 | } |
| 871 | |
| 872 | for (int i = 0; i < (int)mapFds.size(); i++) |
Maciej Żenczykowski | 0eb98a2 | 2024-04-30 22:35:08 -0700 | [diff] [blame] | 873 | ALOGV("map_fd found at %d is %d in %s", i, mapFds[i].get(), elfPath); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 874 | |
| 875 | applyMapRelo(elfFile, mapFds, cs); |
| 876 | |
Maciej Żenczykowski | c1647d7 | 2024-03-10 19:11:58 -0700 | [diff] [blame] | 877 | ret = loadCodeSections(elfPath, cs, string(license.data()), location.prefix); |
Maciej Żenczykowski | e626a95 | 2022-06-17 02:35:36 -0700 | [diff] [blame] | 878 | if (ret) ALOGE("Failed to load programs, loadCodeSections ret=%d", ret); |
Joel Fernandes | d76a200 | 2018-10-16 13:19:58 -0700 | [diff] [blame] | 879 | |
| 880 | return ret; |
| 881 | } |
| 882 | |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 883 | // Networking-related program types are limited to the Tethering Apex |
| 884 | // to prevent things from breaking due to conflicts on mainline updates |
| 885 | // (exception made for socket filters, ie. xt_bpf for potential use in iptables, |
| 886 | // or for attaching to sockets directly) |
| 887 | constexpr bpf_prog_type kPlatformAllowedProgTypes[] = { |
| 888 | BPF_PROG_TYPE_KPROBE, |
| 889 | BPF_PROG_TYPE_PERF_EVENT, |
| 890 | BPF_PROG_TYPE_SOCKET_FILTER, |
| 891 | BPF_PROG_TYPE_TRACEPOINT, |
| 892 | BPF_PROG_TYPE_UNSPEC, // Will be replaced with fuse bpf program type |
| 893 | }; |
| 894 | |
| 895 | constexpr bpf_prog_type kUprobestatsAllowedProgTypes[] = { |
| 896 | BPF_PROG_TYPE_KPROBE, |
| 897 | }; |
| 898 | |
| 899 | // see b/162057235. For arbitrary program types, the concern is that due to the lack of |
| 900 | // SELinux access controls over BPF program attachpoints, we have no way to control the |
| 901 | // attachment of programs to shared resources (or to detect when a shared resource |
| 902 | // has one BPF program replace another that is attached there) |
| 903 | constexpr bpf_prog_type kVendorAllowedProgTypes[] = { |
| 904 | BPF_PROG_TYPE_SOCKET_FILTER, |
| 905 | }; |
| 906 | |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 907 | const Location locations[] = { |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 908 | // Core operating system |
| 909 | { |
| 910 | .dir = "/system/etc/bpf/", |
| 911 | .prefix = "", |
| 912 | .allowedProgTypes = kPlatformAllowedProgTypes, |
| 913 | .allowedProgTypesLength = arraysize(kPlatformAllowedProgTypes), |
| 914 | }, |
| 915 | // uprobestats |
| 916 | { |
| 917 | .dir = "/system/etc/bpf/uprobestats/", |
| 918 | .prefix = "uprobestats/", |
| 919 | .allowedProgTypes = kUprobestatsAllowedProgTypes, |
| 920 | .allowedProgTypesLength = arraysize(kUprobestatsAllowedProgTypes), |
| 921 | }, |
| 922 | // Vendor operating system |
| 923 | { |
| 924 | .dir = "/vendor/etc/bpf/", |
| 925 | .prefix = "vendor/", |
| 926 | .allowedProgTypes = kVendorAllowedProgTypes, |
| 927 | .allowedProgTypesLength = arraysize(kVendorAllowedProgTypes), |
| 928 | }, |
| 929 | }; |
| 930 | |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 931 | int loadAllElfObjects(const Location& location) { |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 932 | int retVal = 0; |
| 933 | DIR* dir; |
| 934 | struct dirent* ent; |
| 935 | |
| 936 | if ((dir = opendir(location.dir)) != NULL) { |
| 937 | while ((ent = readdir(dir)) != NULL) { |
| 938 | string s = ent->d_name; |
| 939 | if (!EndsWith(s, ".o")) continue; |
| 940 | |
| 941 | string progPath(location.dir); |
| 942 | progPath += s; |
| 943 | |
| 944 | bool critical; |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 945 | int ret = loadProg(progPath.c_str(), &critical, location); |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 946 | if (ret) { |
| 947 | if (critical) retVal = ret; |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 948 | ALOGE("Failed to load object: %s, ret: %s", progPath.c_str(), strerror(-ret)); |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 949 | } else { |
| 950 | ALOGV("Loaded object: %s", progPath.c_str()); |
| 951 | } |
| 952 | } |
| 953 | closedir(dir); |
| 954 | } |
| 955 | return retVal; |
| 956 | } |
| 957 | |
| 958 | int createSysFsBpfSubDir(const char* const prefix) { |
| 959 | if (*prefix) { |
| 960 | mode_t prevUmask = umask(0); |
| 961 | |
| 962 | string s = "/sys/fs/bpf/"; |
| 963 | s += prefix; |
| 964 | |
| 965 | errno = 0; |
| 966 | int ret = mkdir(s.c_str(), S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO); |
| 967 | if (ret && errno != EEXIST) { |
| 968 | const int err = errno; |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 969 | ALOGE("Failed to create directory: %s, ret: %s", s.c_str(), strerror(err)); |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 970 | return -err; |
| 971 | } |
| 972 | |
| 973 | umask(prevUmask); |
| 974 | } |
| 975 | return 0; |
| 976 | } |
| 977 | |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 978 | int legacyBpfLoader(int __unused argc, char** argv, char * const envp[]) { |
| 979 | base::InitLogging(argv, &base::KernelLogger); |
Maciej Żenczykowski | e0f1152 | 2024-08-06 15:25:55 -0700 | [diff] [blame] | 980 | |
| 981 | // Load all ELF objects, create programs and maps, and pin them |
| 982 | for (const auto& location : locations) { |
| 983 | if (createSysFsBpfSubDir(location.prefix) || loadAllElfObjects(location)) { |
| 984 | ALOGE("=== CRITICAL FAILURE LOADING BPF PROGRAMS FROM %s ===", location.dir); |
| 985 | ALOGE("If this triggers reliably, you're probably missing kernel options or patches."); |
| 986 | ALOGE("If this triggers randomly, you might be hitting some memory allocation " |
| 987 | "problems or startup script race."); |
| 988 | ALOGE("--- DO NOT EXPECT SYSTEM TO BOOT SUCCESSFULLY ---"); |
| 989 | sleep(20); |
| 990 | return 120; |
| 991 | } |
| 992 | } |
| 993 | |
| 994 | const char * args[] = { "/apex/com.android.tethering/bin/netbpfload", "done", NULL, }; |
| 995 | execve(args[0], (char**)args, envp); |
| 996 | ALOGE("FATAL: execve(): %d[%s]", errno, strerror(errno)); |
| 997 | return 121; |
| 998 | } |
Maciej Żenczykowski | 6d4d9d8 | 2024-08-06 15:32:00 -0700 | [diff] [blame^] | 999 | |
| 1000 | } // namespace bpf |
| 1001 | } // namespace android |