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 android::base::unique_fd;
53 using std::string;
54 
55 #define BPF_PROG_PATH "/system/etc/bpf/"
56 
57 #define CLEANANDEXIT(ret, mapPatterns)                    \
58     do {                                                  \
59         for (size_t i = 0; i < mapPatterns.size(); i++) { \
60             if (mapPatterns[i].fd > -1) {                 \
61                 close(mapPatterns[i].fd);                 \
62             }                                             \
63         }                                                 \
64         return ret;                                       \
65     } while (0)
66 
67 using android::bpf::BpfMapInfo;
68 using android::bpf::BpfProgInfo;
69 
70 void loadAllElfObjects(void) {
71     DIR* dir;
72     struct dirent* ent;
73 
74     if ((dir = opendir(BPF_PROG_PATH)) != NULL) {
75         while ((ent = readdir(dir)) != NULL) {
76             string s = ent->d_name;
77             if (!EndsWith(s, ".o")) continue;
78 
79             string progPath = BPF_PROG_PATH + s;
80 
81             int ret = android::bpf::loadProg(progPath.c_str());
82             ALOGI("Attempted load object: %s, ret: %s", progPath.c_str(), std::strerror(-ret));
83         }
84         closedir(dir);
85     }
86 }
87 
88 int main() {
89     std::string value = android::base::GetProperty("bpf.progs_loaded", "");
90     if (value == "1") {
91         ALOGI("Property bpf.progs_loaded is set, progs already loaded.\n");
92         return 0;
93     }
94 
95     if (android::bpf::getBpfSupportLevel() != android::bpf::BpfLevel::NONE) {
96         // Load all ELF objects, create programs and maps, and pin them
97         loadAllElfObjects();
98     }
99 
100     if (android::base::SetProperty("bpf.progs_loaded", "1") == false) {
101         ALOGE("Failed to set bpf.progs_loaded property\n");
102         return 1;
103     }
104 
105     return 0;
106 }
107