#include #include #include #include #include "libbpf.h" #include "bpf_load.h" #include #include #include #include int main(int ac, char **argv) { int serverfd, serverconnfd, clientfd; socklen_t sockaddr_len; struct sockaddr serv_addr, mapped_addr, tmp_addr; struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in; char filename[256]; char *ip; serv_addr_in = (struct sockaddr_in *)&serv_addr; mapped_addr_in = (struct sockaddr_in *)&mapped_addr; tmp_addr_in = (struct sockaddr_in *)&tmp_addr; snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); if (load_bpf_file(filename)) { printf("%s", bpf_log_buf); return 1; } assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0); assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0); /* Bind server to ephemeral port on lo */ memset(&serv_addr, 0, sizeof(serv_addr)); serv_addr_in->sin_family = AF_INET; serv_addr_in->sin_port = 0; serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK); assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0); sockaddr_len = sizeof(serv_addr); assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0); ip = inet_ntoa(serv_addr_in->sin_addr); printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port)); memset(&mapped_addr, 0, sizeof(mapped_addr)); mapped_addr_in->sin_family = AF_INET; mapped_addr_in->sin_port = htons(5555); mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255"); assert(!bpf_update_elem(map_fd[0], &mapped_addr, &serv_addr, BPF_ANY)); assert(listen(serverfd, 5) == 0); ip = inet_ntoa(mapped_addr_in->sin_addr); printf("Client connecting to: %s:%d\n", ip, ntohs(mapped_addr_in->sin_port)); assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0); sockaddr_len = sizeof(tmp_addr); ip = inet_ntoa(tmp_addr_in->sin_addr); assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0); printf("Server received connection from: %s:%d\n", ip, ntohs(tmp_addr_in->sin_port)); sockaddr_len = sizeof(tmp_addr); assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0); ip = inet_ntoa(tmp_addr_in->sin_addr); printf("Client's peer address: %s:%d\n", ip, ntohs(tmp_addr_in->sin_port)); /* Is the server's getsockname = the socket getpeername */ assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0); return 0; }