samples/bpf/test_probe_write_user_user.c

   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
  12 int 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_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 }