LXR linux/samples/bpf/test_probe_write_user

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