| Sargun Dhillon | cf9b119 | 2016-07-25 05:55:02 -0700 | [diff] [blame] | 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 | } |