1*387f9dfdSAndroid Build Coastguard Worker /*
2*387f9dfdSAndroid Build Coastguard Worker * Copyright (c) Facebook, Inc.
3*387f9dfdSAndroid Build Coastguard Worker * Licensed under the Apache License, Version 2.0 (the "License")
4*387f9dfdSAndroid Build Coastguard Worker *
5*387f9dfdSAndroid Build Coastguard Worker * Usage:
6*387f9dfdSAndroid Build Coastguard Worker * ./SkLocalStorageIterator
7*387f9dfdSAndroid Build Coastguard Worker *
8*387f9dfdSAndroid Build Coastguard Worker * BPF socket local storage map iterator supported is added in 5.9.
9*387f9dfdSAndroid Build Coastguard Worker * But since it takes locks during iterating, it may have performance
10*387f9dfdSAndroid Build Coastguard Worker * implication if in parallel some other bpf program or user space
11*387f9dfdSAndroid Build Coastguard Worker * is doing map update/delete for sockets in the same bucket. The issue
12*387f9dfdSAndroid Build Coastguard Worker * is fixed in 5.10 with the following patch which uses rcu lock instead:
13*387f9dfdSAndroid Build Coastguard Worker * https://lore.kernel.org/bpf/20200916224645.720172-1-yhs@fb.com
14*387f9dfdSAndroid Build Coastguard Worker *
15*387f9dfdSAndroid Build Coastguard Worker * This example shows how to dump local storage data from all sockets
16*387f9dfdSAndroid Build Coastguard Worker * associated with one socket local storage map.
17*387f9dfdSAndroid Build Coastguard Worker * An example output likes below:
18*387f9dfdSAndroid Build Coastguard Worker * family prot val
19*387f9dfdSAndroid Build Coastguard Worker * 2 17 20
20*387f9dfdSAndroid Build Coastguard Worker * 2 17 10
21*387f9dfdSAndroid Build Coastguard Worker */
22*387f9dfdSAndroid Build Coastguard Worker
23*387f9dfdSAndroid Build Coastguard Worker #include <unistd.h>
24*387f9dfdSAndroid Build Coastguard Worker #include <fstream>
25*387f9dfdSAndroid Build Coastguard Worker #include <iostream>
26*387f9dfdSAndroid Build Coastguard Worker #include <string>
27*387f9dfdSAndroid Build Coastguard Worker #include <net/if.h>
28*387f9dfdSAndroid Build Coastguard Worker
29*387f9dfdSAndroid Build Coastguard Worker #include "bcc_version.h"
30*387f9dfdSAndroid Build Coastguard Worker #include "BPF.h"
31*387f9dfdSAndroid Build Coastguard Worker
32*387f9dfdSAndroid Build Coastguard Worker const std::string BPF_PROGRAM = R"(
33*387f9dfdSAndroid Build Coastguard Worker
34*387f9dfdSAndroid Build Coastguard Worker #include <linux/bpf.h>
35*387f9dfdSAndroid Build Coastguard Worker #include <linux/seq_file.h>
36*387f9dfdSAndroid Build Coastguard Worker #include <net/sock.h>
37*387f9dfdSAndroid Build Coastguard Worker
38*387f9dfdSAndroid Build Coastguard Worker /* the structure is defined in .c file, so explicitly define
39*387f9dfdSAndroid Build Coastguard Worker * the structure here.
40*387f9dfdSAndroid Build Coastguard Worker */
41*387f9dfdSAndroid Build Coastguard Worker struct bpf_iter__bpf_sk_storage_map {
42*387f9dfdSAndroid Build Coastguard Worker union {
43*387f9dfdSAndroid Build Coastguard Worker struct bpf_iter_meta *meta;
44*387f9dfdSAndroid Build Coastguard Worker };
45*387f9dfdSAndroid Build Coastguard Worker union {
46*387f9dfdSAndroid Build Coastguard Worker struct bpf_map *map;
47*387f9dfdSAndroid Build Coastguard Worker };
48*387f9dfdSAndroid Build Coastguard Worker union {
49*387f9dfdSAndroid Build Coastguard Worker struct sock *sk;
50*387f9dfdSAndroid Build Coastguard Worker };
51*387f9dfdSAndroid Build Coastguard Worker union {
52*387f9dfdSAndroid Build Coastguard Worker void *value;
53*387f9dfdSAndroid Build Coastguard Worker };
54*387f9dfdSAndroid Build Coastguard Worker };
55*387f9dfdSAndroid Build Coastguard Worker
56*387f9dfdSAndroid Build Coastguard Worker BPF_SK_STORAGE(sk_data_map, __u64);
57*387f9dfdSAndroid Build Coastguard Worker
58*387f9dfdSAndroid Build Coastguard Worker struct info_t {
59*387f9dfdSAndroid Build Coastguard Worker __u32 family;
60*387f9dfdSAndroid Build Coastguard Worker __u32 protocol;
61*387f9dfdSAndroid Build Coastguard Worker __u64 val;
62*387f9dfdSAndroid Build Coastguard Worker };
63*387f9dfdSAndroid Build Coastguard Worker
64*387f9dfdSAndroid Build Coastguard Worker BPF_ITER(bpf_sk_storage_map) {
65*387f9dfdSAndroid Build Coastguard Worker struct seq_file *seq = ctx->meta->seq;
66*387f9dfdSAndroid Build Coastguard Worker struct sock *sk = ctx->sk;
67*387f9dfdSAndroid Build Coastguard Worker __u64 *val = ctx->value;
68*387f9dfdSAndroid Build Coastguard Worker struct info_t info = {};
69*387f9dfdSAndroid Build Coastguard Worker
70*387f9dfdSAndroid Build Coastguard Worker if (sk == (void *)0 || val == (void *)0)
71*387f9dfdSAndroid Build Coastguard Worker return 0;
72*387f9dfdSAndroid Build Coastguard Worker
73*387f9dfdSAndroid Build Coastguard Worker info.family = sk->sk_family;
74*387f9dfdSAndroid Build Coastguard Worker info.protocol = sk->sk_protocol;
75*387f9dfdSAndroid Build Coastguard Worker info.val = *val;
76*387f9dfdSAndroid Build Coastguard Worker bpf_seq_write(seq, &info, sizeof(info));
77*387f9dfdSAndroid Build Coastguard Worker
78*387f9dfdSAndroid Build Coastguard Worker return 0;
79*387f9dfdSAndroid Build Coastguard Worker }
80*387f9dfdSAndroid Build Coastguard Worker )";
81*387f9dfdSAndroid Build Coastguard Worker
82*387f9dfdSAndroid Build Coastguard Worker struct info_t {
83*387f9dfdSAndroid Build Coastguard Worker unsigned family;
84*387f9dfdSAndroid Build Coastguard Worker unsigned protocol;
85*387f9dfdSAndroid Build Coastguard Worker unsigned long long val;
86*387f9dfdSAndroid Build Coastguard Worker };
87*387f9dfdSAndroid Build Coastguard Worker
main()88*387f9dfdSAndroid Build Coastguard Worker int main() {
89*387f9dfdSAndroid Build Coastguard Worker ebpf::BPF bpf;
90*387f9dfdSAndroid Build Coastguard Worker auto res = bpf.init(BPF_PROGRAM);
91*387f9dfdSAndroid Build Coastguard Worker if (!res.ok()) {
92*387f9dfdSAndroid Build Coastguard Worker std::cerr << res.msg() << std::endl;
93*387f9dfdSAndroid Build Coastguard Worker return 1;
94*387f9dfdSAndroid Build Coastguard Worker }
95*387f9dfdSAndroid Build Coastguard Worker
96*387f9dfdSAndroid Build Coastguard Worker // create two sockets
97*387f9dfdSAndroid Build Coastguard Worker int sockfd1 = socket(AF_INET, SOCK_DGRAM, 0);
98*387f9dfdSAndroid Build Coastguard Worker if (sockfd1 < 0) {
99*387f9dfdSAndroid Build Coastguard Worker std::cerr << "socket1 create failure: " << sockfd1 << std::endl;
100*387f9dfdSAndroid Build Coastguard Worker return 1;
101*387f9dfdSAndroid Build Coastguard Worker }
102*387f9dfdSAndroid Build Coastguard Worker
103*387f9dfdSAndroid Build Coastguard Worker int sockfd2 = socket(AF_INET, SOCK_DGRAM, 0);
104*387f9dfdSAndroid Build Coastguard Worker if (sockfd2 < 0) {
105*387f9dfdSAndroid Build Coastguard Worker std::cerr << "socket2 create failure: " << sockfd2 << std::endl;
106*387f9dfdSAndroid Build Coastguard Worker close(sockfd1);
107*387f9dfdSAndroid Build Coastguard Worker return 1;
108*387f9dfdSAndroid Build Coastguard Worker }
109*387f9dfdSAndroid Build Coastguard Worker
110*387f9dfdSAndroid Build Coastguard Worker unsigned long long v1 = 10, v2 = 20;
111*387f9dfdSAndroid Build Coastguard Worker auto sk_table = bpf.get_sk_storage_table<unsigned long long>("sk_data_map");
112*387f9dfdSAndroid Build Coastguard Worker
113*387f9dfdSAndroid Build Coastguard Worker res = sk_table.update_value(sockfd1, v1);
114*387f9dfdSAndroid Build Coastguard Worker if (!res.ok()) {
115*387f9dfdSAndroid Build Coastguard Worker std::cerr << "sk_data_map sockfd1 update failure: " << res.msg() << std::endl;
116*387f9dfdSAndroid Build Coastguard Worker close(sockfd2);
117*387f9dfdSAndroid Build Coastguard Worker close(sockfd1);
118*387f9dfdSAndroid Build Coastguard Worker return 1;
119*387f9dfdSAndroid Build Coastguard Worker }
120*387f9dfdSAndroid Build Coastguard Worker
121*387f9dfdSAndroid Build Coastguard Worker res = sk_table.update_value(sockfd2, v2);
122*387f9dfdSAndroid Build Coastguard Worker if (!res.ok()) {
123*387f9dfdSAndroid Build Coastguard Worker std::cerr << "sk_data_map sockfd2 update failure: " << res.msg() << std::endl;
124*387f9dfdSAndroid Build Coastguard Worker close(sockfd2);
125*387f9dfdSAndroid Build Coastguard Worker close(sockfd1);
126*387f9dfdSAndroid Build Coastguard Worker return 1;
127*387f9dfdSAndroid Build Coastguard Worker }
128*387f9dfdSAndroid Build Coastguard Worker
129*387f9dfdSAndroid Build Coastguard Worker int prog_fd;
130*387f9dfdSAndroid Build Coastguard Worker res = bpf.load_func("bpf_iter__bpf_sk_storage_map", BPF_PROG_TYPE_TRACING, prog_fd);
131*387f9dfdSAndroid Build Coastguard Worker if (!res.ok()) {
132*387f9dfdSAndroid Build Coastguard Worker std::cerr << res.msg() << std::endl;
133*387f9dfdSAndroid Build Coastguard Worker return 1;
134*387f9dfdSAndroid Build Coastguard Worker }
135*387f9dfdSAndroid Build Coastguard Worker
136*387f9dfdSAndroid Build Coastguard Worker union bpf_iter_link_info link_info = {};
137*387f9dfdSAndroid Build Coastguard Worker link_info.map.map_fd = sk_table.get_fd();
138*387f9dfdSAndroid Build Coastguard Worker int link_fd = bcc_iter_attach(prog_fd, &link_info, sizeof(union bpf_iter_link_info));
139*387f9dfdSAndroid Build Coastguard Worker if (link_fd < 0) {
140*387f9dfdSAndroid Build Coastguard Worker std::cerr << "bcc_iter_attach failed: " << link_fd << std::endl;
141*387f9dfdSAndroid Build Coastguard Worker close(sockfd2);
142*387f9dfdSAndroid Build Coastguard Worker close(sockfd1);
143*387f9dfdSAndroid Build Coastguard Worker return 1;
144*387f9dfdSAndroid Build Coastguard Worker }
145*387f9dfdSAndroid Build Coastguard Worker
146*387f9dfdSAndroid Build Coastguard Worker int iter_fd = bcc_iter_create(link_fd);
147*387f9dfdSAndroid Build Coastguard Worker if (iter_fd < 0) {
148*387f9dfdSAndroid Build Coastguard Worker std::cerr << "bcc_iter_create failed: " << iter_fd << std::endl;
149*387f9dfdSAndroid Build Coastguard Worker close(link_fd);
150*387f9dfdSAndroid Build Coastguard Worker close(sockfd2);
151*387f9dfdSAndroid Build Coastguard Worker close(sockfd1);
152*387f9dfdSAndroid Build Coastguard Worker return 1;
153*387f9dfdSAndroid Build Coastguard Worker }
154*387f9dfdSAndroid Build Coastguard Worker
155*387f9dfdSAndroid Build Coastguard Worker // Header.
156*387f9dfdSAndroid Build Coastguard Worker printf("family\tprot\tval\n");
157*387f9dfdSAndroid Build Coastguard Worker
158*387f9dfdSAndroid Build Coastguard Worker struct info_t info[20];
159*387f9dfdSAndroid Build Coastguard Worker int len, leftover = 0, info_size = 20 * sizeof(struct info_t);
160*387f9dfdSAndroid Build Coastguard Worker while ((len = read(iter_fd, (char *)info + leftover, info_size - leftover))) {
161*387f9dfdSAndroid Build Coastguard Worker if (len < 0) {
162*387f9dfdSAndroid Build Coastguard Worker if (len == -EAGAIN)
163*387f9dfdSAndroid Build Coastguard Worker continue;
164*387f9dfdSAndroid Build Coastguard Worker std::cerr << "read failed: " << len << std::endl;
165*387f9dfdSAndroid Build Coastguard Worker break;
166*387f9dfdSAndroid Build Coastguard Worker }
167*387f9dfdSAndroid Build Coastguard Worker
168*387f9dfdSAndroid Build Coastguard Worker int num_info = len / sizeof(struct info_t);
169*387f9dfdSAndroid Build Coastguard Worker for (int i = 0; i < num_info; i++) {
170*387f9dfdSAndroid Build Coastguard Worker printf("%d\t%d\t%lld\n", info[i].family, info[i].protocol, info[i].val);
171*387f9dfdSAndroid Build Coastguard Worker }
172*387f9dfdSAndroid Build Coastguard Worker
173*387f9dfdSAndroid Build Coastguard Worker leftover = len % sizeof(struct info_t);
174*387f9dfdSAndroid Build Coastguard Worker if (num_info > 0)
175*387f9dfdSAndroid Build Coastguard Worker memcpy(info, (void *)&info[num_info], leftover);
176*387f9dfdSAndroid Build Coastguard Worker }
177*387f9dfdSAndroid Build Coastguard Worker
178*387f9dfdSAndroid Build Coastguard Worker close(iter_fd);
179*387f9dfdSAndroid Build Coastguard Worker close(link_fd);
180*387f9dfdSAndroid Build Coastguard Worker close(sockfd2);
181*387f9dfdSAndroid Build Coastguard Worker close(sockfd1);
182*387f9dfdSAndroid Build Coastguard Worker return 0;
183*387f9dfdSAndroid Build Coastguard Worker }
184