1 /*
2  * Copyright (C) 2017 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 
17 #ifndef LOG_TAG
18 #define LOG_TAG "bpfloader"
19 #endif
20 
21 #include <arpa/inet.h>
22 #include <dirent.h>
23 #include <elf.h>
24 #include <error.h>
25 #include <fcntl.h>
26 #include <inttypes.h>
27 #include <linux/bpf.h>
28 #include <linux/unistd.h>
29 #include <net/if.h>
30 #include <stdint.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35 
36 #include <sys/mman.h>
37 #include <sys/socket.h>
38 #include <sys/stat.h>
39 #include <sys/types.h>
40 
41 #include <android-base/properties.h>
42 #include <android-base/stringprintf.h>
43 #include <android-base/strings.h>
44 #include <android-base/unique_fd.h>
45 #include <libbpf_android.h>
46 #include <log/log.h>
47 #include <netdutils/Misc.h>
48 #include <netdutils/Slice.h>
49 #include "bpf/BpfUtils.h"
50 
51 using android::base::EndsWith;
52 using std::string;
53 
54 #define BPF_PROG_PATH "/system/etc/bpf/"
55 
56 int loadAllElfObjects(void) {
57     int retVal = 0;
58     DIR* dir;
59     struct dirent* ent;
60 
61     if ((dir = opendir(BPF_PROG_PATH)) != NULL) {
62         while ((ent = readdir(dir)) != NULL) {
63             string s = ent->d_name;
64             if (!EndsWith(s, ".o")) continue;
65 
66             string progPath = BPF_PROG_PATH + s;
67 
68             bool critical;
69             int ret = android::bpf::loadProg(progPath.c_str(), &critical);
70             if (ret) {
71                 if (critical) retVal = ret;
72                 ALOGE("Failed to load object: %s, ret: %s", progPath.c_str(), std::strerror(-ret));
73             } else {
74                 ALOGI("Loaded object: %s", progPath.c_str());
75             }
76         }
77         closedir(dir);
78     }
79     return retVal;
80 }
81 
82 int main() {
83     if (!android::bpf::isBpfSupported()) return 0;
84 
85     // Load all ELF objects, create programs and maps, and pin them
86     if (loadAllElfObjects() != 0) {
87         ALOGE("=== CRITICAL FAILURE LOADING BPF PROGRAMS ===");
88         ALOGE("If this triggers reliably, you're probably missing kernel options or patches.");
89         ALOGE("If this triggers randomly, you might be hitting some memory allocation problems or "
90               "startup script race.");
91         ALOGE("--- DO NOT EXPECT SYSTEM TO BOOT SUCCESSFULLY ---");
92         return 2;
93     }
94 
95     if (android::base::SetProperty("bpf.progs_loaded", "1") == false) {
96         ALOGE("Failed to set bpf.progs_loaded property");
97         return 1;
98     }
99 
100     return 0;
101 }
102