mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-14 15:54:15 +08:00
3677d0a131
For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing kprobe tracing programs with libbbpf
bpf loader.
- For kprobe events pointing to system calls, the SYSCALL() macro in
trace_common.h was used.
- Adding a kprobe event and attaching a bpf program to it was done
through bpf_program_attach().
- Instead of using the existing BPF MAP definition, MAP definition
has been refactored with the new BTF-defined MAP format.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200823085334.9413-3-danieltimlee@gmail.com
109 lines
3.3 KiB
C
109 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <stdio.h>
|
|
#include <assert.h>
|
|
#include <unistd.h>
|
|
#include <bpf/bpf.h>
|
|
#include <bpf/libbpf.h>
|
|
#include <sys/socket.h>
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
|
|
int main(int ac, char **argv)
|
|
{
|
|
struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
|
|
struct sockaddr serv_addr, mapped_addr, tmp_addr;
|
|
int serverfd, serverconnfd, clientfd, map_fd;
|
|
struct bpf_link *link = NULL;
|
|
struct bpf_program *prog;
|
|
struct bpf_object *obj;
|
|
socklen_t sockaddr_len;
|
|
char filename[256];
|
|
char *ip;
|
|
|
|
serv_addr_in = (struct sockaddr_in *)&serv_addr;
|
|
mapped_addr_in = (struct sockaddr_in *)&mapped_addr;
|
|
tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
|
|
|
|
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
|
|
obj = bpf_object__open_file(filename, NULL);
|
|
if (libbpf_get_error(obj)) {
|
|
fprintf(stderr, "ERROR: opening BPF object file failed\n");
|
|
return 0;
|
|
}
|
|
|
|
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
|
|
if (libbpf_get_error(prog)) {
|
|
fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
/* load BPF program */
|
|
if (bpf_object__load(obj)) {
|
|
fprintf(stderr, "ERROR: loading BPF object file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
map_fd = bpf_object__find_map_fd_by_name(obj, "dnat_map");
|
|
if (map_fd < 0) {
|
|
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
link = bpf_program__attach(prog);
|
|
if (libbpf_get_error(link)) {
|
|
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
|
|
link = NULL;
|
|
goto cleanup;
|
|
}
|
|
|
|
assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
|
|
assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
|
|
|
|
/* Bind server to ephemeral port on lo */
|
|
memset(&serv_addr, 0, sizeof(serv_addr));
|
|
serv_addr_in->sin_family = AF_INET;
|
|
serv_addr_in->sin_port = 0;
|
|
serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
|
|
|
|
assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0);
|
|
|
|
sockaddr_len = sizeof(serv_addr);
|
|
assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0);
|
|
ip = inet_ntoa(serv_addr_in->sin_addr);
|
|
printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port));
|
|
|
|
memset(&mapped_addr, 0, sizeof(mapped_addr));
|
|
mapped_addr_in->sin_family = AF_INET;
|
|
mapped_addr_in->sin_port = htons(5555);
|
|
mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
|
|
|
|
assert(!bpf_map_update_elem(map_fd, &mapped_addr, &serv_addr, BPF_ANY));
|
|
|
|
assert(listen(serverfd, 5) == 0);
|
|
|
|
ip = inet_ntoa(mapped_addr_in->sin_addr);
|
|
printf("Client connecting to: %s:%d\n",
|
|
ip, ntohs(mapped_addr_in->sin_port));
|
|
assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0);
|
|
|
|
sockaddr_len = sizeof(tmp_addr);
|
|
ip = inet_ntoa(tmp_addr_in->sin_addr);
|
|
assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0);
|
|
printf("Server received connection from: %s:%d\n",
|
|
ip, ntohs(tmp_addr_in->sin_port));
|
|
|
|
sockaddr_len = sizeof(tmp_addr);
|
|
assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0);
|
|
ip = inet_ntoa(tmp_addr_in->sin_addr);
|
|
printf("Client's peer address: %s:%d\n",
|
|
ip, ntohs(tmp_addr_in->sin_port));
|
|
|
|
/* Is the server's getsockname = the socket getpeername */
|
|
assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
|
|
|
|
cleanup:
|
|
bpf_link__destroy(link);
|
|
bpf_object__close(obj);
|
|
return 0;
|
|
}
|