test_probe_write_user_user.c 3.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <stdio.h>
  3. #include <assert.h>
  4. #include <unistd.h>
  5. #include <bpf/bpf.h>
  6. #include <bpf/libbpf.h>
  7. #include <sys/socket.h>
  8. #include <netinet/in.h>
  9. #include <arpa/inet.h>
  10. int main(int ac, char **argv)
  11. {
  12. struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
  13. struct sockaddr serv_addr, mapped_addr, tmp_addr;
  14. int serverfd, serverconnfd, clientfd, map_fd;
  15. struct bpf_link *link = NULL;
  16. struct bpf_program *prog;
  17. struct bpf_object *obj;
  18. socklen_t sockaddr_len;
  19. char filename[256];
  20. char *ip;
  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. snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  25. obj = bpf_object__open_file(filename, NULL);
  26. if (libbpf_get_error(obj)) {
  27. fprintf(stderr, "ERROR: opening BPF object file failed\n");
  28. return 0;
  29. }
  30. prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
  31. if (libbpf_get_error(prog)) {
  32. fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
  33. goto cleanup;
  34. }
  35. /* load BPF program */
  36. if (bpf_object__load(obj)) {
  37. fprintf(stderr, "ERROR: loading BPF object file failed\n");
  38. goto cleanup;
  39. }
  40. map_fd = bpf_object__find_map_fd_by_name(obj, "dnat_map");
  41. if (map_fd < 0) {
  42. fprintf(stderr, "ERROR: finding a map in obj file failed\n");
  43. goto cleanup;
  44. }
  45. link = bpf_program__attach(prog);
  46. if (libbpf_get_error(link)) {
  47. fprintf(stderr, "ERROR: bpf_program__attach failed\n");
  48. link = NULL;
  49. goto cleanup;
  50. }
  51. assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
  52. assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
  53. /* Bind server to ephemeral port on lo */
  54. memset(&serv_addr, 0, sizeof(serv_addr));
  55. serv_addr_in->sin_family = AF_INET;
  56. serv_addr_in->sin_port = 0;
  57. serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  58. assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0);
  59. sockaddr_len = sizeof(serv_addr);
  60. assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0);
  61. ip = inet_ntoa(serv_addr_in->sin_addr);
  62. printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port));
  63. memset(&mapped_addr, 0, sizeof(mapped_addr));
  64. mapped_addr_in->sin_family = AF_INET;
  65. mapped_addr_in->sin_port = htons(5555);
  66. mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
  67. assert(!bpf_map_update_elem(map_fd, &mapped_addr, &serv_addr, BPF_ANY));
  68. assert(listen(serverfd, 5) == 0);
  69. ip = inet_ntoa(mapped_addr_in->sin_addr);
  70. printf("Client connecting to: %s:%d\n",
  71. ip, ntohs(mapped_addr_in->sin_port));
  72. assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0);
  73. sockaddr_len = sizeof(tmp_addr);
  74. ip = inet_ntoa(tmp_addr_in->sin_addr);
  75. assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0);
  76. printf("Server received connection from: %s:%d\n",
  77. ip, ntohs(tmp_addr_in->sin_port));
  78. sockaddr_len = sizeof(tmp_addr);
  79. assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0);
  80. ip = inet_ntoa(tmp_addr_in->sin_addr);
  81. printf("Client's peer address: %s:%d\n",
  82. ip, ntohs(tmp_addr_in->sin_port));
  83. /* Is the server's getsockname = the socket getpeername */
  84. assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
  85. cleanup:
  86. bpf_link__destroy(link);
  87. bpf_object__close(obj);
  88. return 0;
  89. }