/* this loads the module and sets up some services */ #include #include #include #include #include #include #include #include int kserv_running = 0; int kserv_shutdown = 0; static char *hello_world = "hello world\n\n\0\0\0\0\0\0\0\0"; /* ---------------------------------------------------------------- * get a socket for communication * ---------------------------------------------------------------- */ static int kserv_sock(struct socket **psock, int port) { int ret = 0; struct sockaddr_in sin; struct socket *sock; printk("-> kserv_sock\n"); *psock = NULL; /* create a socket for local use */ ret = sock_create(PF_INET,SOCK_STREAM,IPPROTO_TCP,&sock); if( ret < 0 ) { printk(KERN_ERR "kserv: failed to sock_create\n"); goto no_sock; } /* bind it to a port */ sock->sk->reuse = 1; /* multi-thread TCP */ sin.sin_family = AF_INET; sin.sin_addr.s_addr = INADDR_ANY; sin.sin_port = htons(port); ret = sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin)); if( ret < 0 ) { printk(KERN_ERR "kserv: failed to bind\n"); goto no_bind; } /* start the litening */ ret = sock->ops->listen(sock,5); if( ret < 0 ) { printk(KERN_ERR "kserv: failed to listen\n"); goto no_listen; } /* socket was successfuly started */ *psock = sock; return 0; /* error handling */ no_listen: no_bind: sock_release(sock); no_sock: printk("<- kserv_sock\n"); return ret; } /* ---------------------------------------------------------------- * detach from world * ---------------------------------------------------------------- */ static int kserv_main(void *arg) { int ret=0; sigset_t tmpsig; struct socket *sock; struct socket *newsock = NULL; printk("-> kserv_main\n"); /* become a kernel thread called 'skerv_main' */ sprintf(current->comm,"kserv_main"); daemonize(); /* Block all signals except SIGKILL and SIGSTOP */ spin_lock_irq(¤t->sigmask_lock); tmpsig = current->blocked; siginitsetinv(¤t->blocked, sigmask(SIGKILL) | sigmask(SIGSTOP) ); recalc_sigpending(current); spin_unlock_irq(¤t->sigmask_lock); #if 0 /* close all opened files in user/space */ for(i=255;i>=0;i--) if( current->files->fd[i] ) close(i); #endif /* get a socket */ ret = kserv_sock( &sock, 8888 ); if( ret ) goto bail; kserv_running = 1; kserv_shutdown = 0; /* main loop */ printk(" main loop\n"); while ( kserv_running ) { if( !newsock ) newsock = sock_alloc(); if( !newsock ) { printk(KERN_ERR "kserv: failed to sock_alloc\n"); kserv_running = 0; } else { /* we have a new socket */ newsock->type = sock->type; newsock->ops = sock->ops; /* accept a connection */ ret=sock->ops->accept(sock, newsock, O_NONBLOCK); if( ret == -EAGAIN ) { /* need to rest a while */ DECLARE_WAIT_QUEUE_HEAD(wait); interruptible_sleep_on_timeout(&wait,HZ); } else if( ret ) { printk(KERN_ERR "kserv: failed to accept %d\n",ret); sock_release(newsock); kserv_running = 0; } else if ( newsock->sk->state==TCP_CLOSE ) { printk(KERN_ERR "kserv: state of socket is invalid (TCP_CLOSE)\n"); sock_release(newsock); kserv_running = 0; } else { int space, len = 13; DECLARE_WAIT_QUEUE_HEAD(wait); interruptible_sleep_on_timeout(&wait,HZ); switch( newsock->state) { case TCP_CLOSE: printk(" state=TCP_CLOSE\n"); break; case TCP_CLOSE_WAIT: printk(" state=TCP_CLOSE_WAIT\n"); break; case TCP_CLOSING: printk(" state=TCP_CLOSING\n"); break; case TCP_ESTABLISHED: printk(" state=TCP_ESTABLISHED\n"); break; case TCP_FIN_WAIT1: printk(" state=TCP_FIN_WAIT1\n"); break; case TCP_FIN_WAIT2: printk(" state=TCP_FIN_WAIT2\n"); break; case TCP_LAST_ACK: printk(" state=TCP_LAST_ACK\n"); break; case TCP_LISTEN: printk(" state=TCP_LISTEN\n"); break; case TCP_SYN_RECV: printk(" state=TCP_SYN_RECV\n"); break; case TCP_SYN_SENT: printk(" state=TCP_SYN_SENT\n"); break; case TCP_TIME_WAIT: printk(" state=TCP_TIME_WAIT\n"); break; default: printk(" state=%d\n",newsock->state); } space = sock_wspace(newsock->sk); if( space < len ) { printk(KERN_ERR "kserv: not enough wspace for msg\n"); sock_release(newsock); kserv_running = 0; } else { struct msghdr msg; mm_segment_t oldfs; struct iovec iov; iov.iov_len = len; iov.iov_base = hello_world; msg.msg_name = 0; msg.msg_namelen = 0; msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = 0;//MSG_NOSIGNAL; printk(" -> sendmsg\n"); oldfs = get_fs(); set_fs(KERNEL_DS); printk(" sock_sendmsg(%p,%p,%d);\n",newsock, msg, len ); len = sock_sendmsg(newsock,&msg,(size_t)(len)); set_fs(oldfs); printk(" <- sendmsg\n"); } /* for now we will exit after one transaction... */ kserv_running = 0; } } } /* start the shutdown */ sock_release(sock); kserv_shutdown = 1; bail: /* about to exit */ printk("kserv: module can be unloaded now\n"); MOD_DEC_USE_COUNT; printk("<- kserv_main\n"); return 0; } /* ---------------------------------------------------------------- * called on insmod * ---------------------------------------------------------------- */ static int __init init(void) { printk("-> init\n"); MOD_INC_USE_COUNT; kernel_thread(kserv_main, /* main function */ NULL /* no arg */, 0 /* no clone flags */ ); printk("<- init\n"); return 0; } /* ---------------------------------------------------------------- * called on rmmod * ---------------------------------------------------------------- */ static void __exit fini(void) { printk("-> fini\n"); printk("<- fini\n"); } /* ---------------------------------------------------------------- * define module entry and exit * ---------------------------------------------------------------- */ module_init(init); module_exit(fini);