LXR linux/samples/bpf/test_probe_write_user

   1// SPDX-License-Identifier: GPL-2.0
   2#include <stdio.h>
   3#include <assert.h>
   4#include <linux/bpf.h>
   5#include <unistd.h>
   6#include "libbpf.h"
   7#include "bpf_load.h"
   8#include <sys/socket.h>
   9#include <string.h>
  10#include <netinet/in.h>
  11#include <arpa/inet.h>
  12
  13int main(int ac, char **argv)
  14{
  15        int serverfd, serverconnfd, clientfd;
  16        socklen_t sockaddr_len;
  17        struct sockaddr serv_addr, mapped_addr, tmp_addr;
  18        struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
  19        char filename[256];
  20        char *ip;
  21
  22        serv_addr_in = (struct sockaddr_in *)&serv_addr;
  23        mapped_addr_in = (struct sockaddr_in *)&mapped_addr;
  24        tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
  25
  26        snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  27
  28        if (load_bpf_file(filename)) {
  29                printf("%s", bpf_log_buf);
  30                return 1;
  31        }
  32
  33        assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
  34        assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
  35
  36        /* Bind server to ephemeral port on lo */
  37        memset(&serv_addr, 0, sizeof(serv_addr));
  38        serv_addr_in->sin_family = AF_INET;
  39        serv_addr_in->sin_port = 0;
  40        serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  41
  42        assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0);
  43
  44        sockaddr_len = sizeof(serv_addr);
  45        assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0);
  46        ip = inet_ntoa(serv_addr_in->sin_addr);
  47        printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port));
  48
  49        memset(&mapped_addr, 0, sizeof(mapped_addr));
  50        mapped_addr_in->sin_family = AF_INET;
  51        mapped_addr_in->sin_port = htons(5555);
  52        mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
  53
  54        assert(!bpf_map_update_elem(map_fd[0], &mapped_addr, &serv_addr, BPF_ANY));
  55
  56        assert(listen(serverfd, 5) == 0);
  57
  58        ip = inet_ntoa(mapped_addr_in->sin_addr);
  59        printf("Client connecting to: %s:%d\n",
  60               ip, ntohs(mapped_addr_in->sin_port));
  61        assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0);
  62
  63        sockaddr_len = sizeof(tmp_addr);
  64        ip = inet_ntoa(tmp_addr_in->sin_addr);
  65        assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0);
  66        printf("Server received connection from: %s:%d\n",
  67               ip, ntohs(tmp_addr_in->sin_port));
  68
  69        sockaddr_len = sizeof(tmp_addr);
  70        assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0);
  71        ip = inet_ntoa(tmp_addr_in->sin_addr);
  72        printf("Client's peer address: %s:%d\n",
  73               ip, ntohs(tmp_addr_in->sin_port));
  74
  75        /* Is the server's getsockname = the socket getpeername */
  76        assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
  77
  78        return 0;
  79}
  80