2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
3 * Licensed under the GPL
6 #include "linux/completion.h"
7 #include "linux/interrupt.h"
8 #include "linux/list.h"
9 #include "linux/mutex.h"
10 #include "linux/workqueue.h"
11 #include "asm/atomic.h"
18 struct list_head list;
21 struct completion done;
25 struct list_head pending;
26 struct list_head connections;
30 struct port_list *port;
36 struct list_head list;
41 struct port_list *port;
44 static irqreturn_t pipe_interrupt(int irq, void *data)
46 struct connection *conn = data;
49 fd = os_rcv_fd(conn->socket[0], &conn->helper_pid);
54 printk(KERN_ERR "pipe_interrupt : os_rcv_fd returned %d\n",
56 os_close_file(conn->fd);
59 list_del(&conn->list);
62 list_add(&conn->list, &conn->port->connections);
64 complete(&conn->port->done);
68 #define NO_WAITER_MSG \
70 "There are currently no UML consoles waiting for port connections.\n" \
71 "Either disconnect from one to make it available or activate some more\n" \
72 "by enabling more consoles in the UML /etc/inittab.\n" \
75 static int port_accept(struct port_list *port)
77 struct connection *conn;
78 int fd, socket[2], pid;
80 fd = port_connection(port->fd, socket, &pid);
83 printk(KERN_ERR "port_accept : port_connection "
84 "returned %d\n", -fd);
88 conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
90 printk(KERN_ERR "port_accept : failed to allocate "
94 *conn = ((struct connection)
95 { .list = LIST_HEAD_INIT(conn->list),
97 .socket = { socket[0], socket[1] },
101 if (um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt,
102 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
104 printk(KERN_ERR "port_accept : failed to get IRQ for "
109 if (atomic_read(&port->wait_count) == 0) {
110 os_write_file(fd, NO_WAITER_MSG, sizeof(NO_WAITER_MSG));
111 printk(KERN_ERR "No one waiting for port\n");
113 list_add(&conn->list, &port->pending);
120 os_kill_process(pid, 1);
125 static DEFINE_MUTEX(ports_mutex);
126 static LIST_HEAD(ports);
128 static void port_work_proc(struct work_struct *unused)
130 struct port_list *port;
131 struct list_head *ele;
134 local_irq_save(flags);
135 list_for_each(ele, &ports) {
136 port = list_entry(ele, struct port_list, list);
137 if (!port->has_connection)
140 reactivate_fd(port->fd, ACCEPT_IRQ);
141 while (port_accept(port))
143 port->has_connection = 0;
145 local_irq_restore(flags);
148 DECLARE_WORK(port_work, port_work_proc);
150 static irqreturn_t port_interrupt(int irq, void *data)
152 struct port_list *port = data;
154 port->has_connection = 1;
155 schedule_work(&port_work);
159 void *port_data(int port_num)
161 struct list_head *ele;
162 struct port_list *port;
163 struct port_dev *dev = NULL;
166 mutex_lock(&ports_mutex);
167 list_for_each(ele, &ports) {
168 port = list_entry(ele, struct port_list, list);
169 if (port->port == port_num)
172 port = kmalloc(sizeof(struct port_list), GFP_KERNEL);
174 printk(KERN_ERR "Allocation of port list failed\n");
178 fd = port_listen_fd(port_num);
180 printk(KERN_ERR "binding to port %d failed, errno = %d\n",
185 if (um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt,
186 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
188 printk(KERN_ERR "Failed to get IRQ for port %d\n", port_num);
192 *port = ((struct port_list)
193 { .list = LIST_HEAD_INIT(port->list),
194 .wait_count = ATOMIC_INIT(0),
198 .pending = LIST_HEAD_INIT(port->pending),
199 .connections = LIST_HEAD_INIT(port->connections) });
200 spin_lock_init(&port->lock);
201 init_completion(&port->done);
202 list_add(&port->list, &ports);
205 dev = kmalloc(sizeof(struct port_dev), GFP_KERNEL);
207 printk(KERN_ERR "Allocation of port device entry failed\n");
211 *dev = ((struct port_dev) { .port = port,
213 .telnetd_pid = -1 });
221 mutex_unlock(&ports_mutex);
225 int port_wait(void *data)
227 struct port_dev *dev = data;
228 struct connection *conn;
229 struct port_list *port = dev->port;
232 atomic_inc(&port->wait_count);
235 if (wait_for_completion_interruptible(&port->done))
238 spin_lock(&port->lock);
240 conn = list_entry(port->connections.next, struct connection,
242 list_del(&conn->list);
243 spin_unlock(&port->lock);
245 os_shutdown_socket(conn->socket[0], 1, 1);
246 os_close_file(conn->socket[0]);
247 os_shutdown_socket(conn->socket[1], 1, 1);
248 os_close_file(conn->socket[1]);
250 /* This is done here because freeing an IRQ can't be done
251 * within the IRQ handler. So, pipe_interrupt always ups
252 * the semaphore regardless of whether it got a successful
253 * connection. Then we loop here throwing out failed
254 * connections until a good one is found.
256 free_irq(TELNETD_IRQ, conn);
260 os_close_file(conn->fd);
265 dev->helper_pid = conn->helper_pid;
266 dev->telnetd_pid = conn->telnetd_pid;
269 atomic_dec(&port->wait_count);
273 void port_remove_dev(void *d)
275 struct port_dev *dev = d;
277 if (dev->helper_pid != -1)
278 os_kill_process(dev->helper_pid, 0);
279 if (dev->telnetd_pid != -1)
280 os_kill_process(dev->telnetd_pid, 1);
281 dev->helper_pid = -1;
282 dev->telnetd_pid = -1;
285 void port_kern_free(void *d)
287 struct port_dev *dev = d;
289 port_remove_dev(dev);
293 static void free_port(void)
295 struct list_head *ele;
296 struct port_list *port;
298 list_for_each(ele, &ports) {
299 port = list_entry(ele, struct port_list, list);
300 free_irq_by_fd(port->fd);
301 os_close_file(port->fd);
305 __uml_exitcall(free_port);