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303 lines
6.4 KiB
303 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) |
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*/ |
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#include <linux/completion.h> |
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#include <linux/interrupt.h> |
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#include <linux/list.h> |
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#include <linux/mutex.h> |
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#include <linux/slab.h> |
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#include <linux/workqueue.h> |
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#include <asm/atomic.h> |
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#include <init.h> |
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#include <irq_kern.h> |
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#include <os.h> |
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#include "port.h" |
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struct port_list { |
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struct list_head list; |
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atomic_t wait_count; |
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int has_connection; |
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struct completion done; |
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int port; |
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int fd; |
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spinlock_t lock; |
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struct list_head pending; |
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struct list_head connections; |
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}; |
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struct port_dev { |
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struct port_list *port; |
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int helper_pid; |
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int telnetd_pid; |
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}; |
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struct connection { |
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struct list_head list; |
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int fd; |
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int helper_pid; |
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int socket[2]; |
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int telnetd_pid; |
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struct port_list *port; |
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}; |
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static irqreturn_t pipe_interrupt(int irq, void *data) |
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{ |
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struct connection *conn = data; |
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int fd; |
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fd = os_rcv_fd(conn->socket[0], &conn->helper_pid); |
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if (fd < 0) { |
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if (fd == -EAGAIN) |
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return IRQ_NONE; |
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printk(KERN_ERR "pipe_interrupt : os_rcv_fd returned %d\n", |
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-fd); |
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os_close_file(conn->fd); |
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} |
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list_del(&conn->list); |
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conn->fd = fd; |
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list_add(&conn->list, &conn->port->connections); |
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complete(&conn->port->done); |
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return IRQ_HANDLED; |
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} |
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#define NO_WAITER_MSG \ |
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"****\n" \ |
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"There are currently no UML consoles waiting for port connections.\n" \ |
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"Either disconnect from one to make it available or activate some more\n" \ |
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"by enabling more consoles in the UML /etc/inittab.\n" \ |
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"****\n" |
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static int port_accept(struct port_list *port) |
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{ |
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struct connection *conn; |
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int fd, socket[2], pid; |
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fd = port_connection(port->fd, socket, &pid); |
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if (fd < 0) { |
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if (fd != -EAGAIN) |
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printk(KERN_ERR "port_accept : port_connection " |
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"returned %d\n", -fd); |
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goto out; |
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} |
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conn = kmalloc(sizeof(*conn), GFP_ATOMIC); |
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if (conn == NULL) { |
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printk(KERN_ERR "port_accept : failed to allocate " |
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"connection\n"); |
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goto out_close; |
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} |
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*conn = ((struct connection) |
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{ .list = LIST_HEAD_INIT(conn->list), |
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.fd = fd, |
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.socket = { socket[0], socket[1] }, |
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.telnetd_pid = pid, |
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.port = port }); |
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if (um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt, |
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IRQF_SHARED, "telnetd", conn) < 0) { |
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printk(KERN_ERR "port_accept : failed to get IRQ for " |
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"telnetd\n"); |
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goto out_free; |
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} |
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if (atomic_read(&port->wait_count) == 0) { |
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os_write_file(fd, NO_WAITER_MSG, sizeof(NO_WAITER_MSG)); |
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printk(KERN_ERR "No one waiting for port\n"); |
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} |
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list_add(&conn->list, &port->pending); |
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return 1; |
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out_free: |
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kfree(conn); |
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out_close: |
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os_close_file(fd); |
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os_kill_process(pid, 1); |
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out: |
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return 0; |
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} |
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static DEFINE_MUTEX(ports_mutex); |
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static LIST_HEAD(ports); |
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static void port_work_proc(struct work_struct *unused) |
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{ |
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struct port_list *port; |
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struct list_head *ele; |
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unsigned long flags; |
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local_irq_save(flags); |
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list_for_each(ele, &ports) { |
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port = list_entry(ele, struct port_list, list); |
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if (!port->has_connection) |
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continue; |
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while (port_accept(port)) |
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; |
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port->has_connection = 0; |
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} |
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local_irq_restore(flags); |
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} |
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DECLARE_WORK(port_work, port_work_proc); |
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static irqreturn_t port_interrupt(int irq, void *data) |
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{ |
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struct port_list *port = data; |
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port->has_connection = 1; |
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schedule_work(&port_work); |
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return IRQ_HANDLED; |
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} |
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void *port_data(int port_num) |
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{ |
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struct list_head *ele; |
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struct port_list *port; |
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struct port_dev *dev = NULL; |
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int fd; |
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mutex_lock(&ports_mutex); |
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list_for_each(ele, &ports) { |
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port = list_entry(ele, struct port_list, list); |
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if (port->port == port_num) |
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goto found; |
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} |
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port = kmalloc(sizeof(struct port_list), GFP_KERNEL); |
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if (port == NULL) { |
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printk(KERN_ERR "Allocation of port list failed\n"); |
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goto out; |
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} |
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fd = port_listen_fd(port_num); |
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if (fd < 0) { |
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printk(KERN_ERR "binding to port %d failed, errno = %d\n", |
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port_num, -fd); |
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goto out_free; |
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} |
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if (um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt, |
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IRQF_SHARED, "port", port) < 0) { |
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printk(KERN_ERR "Failed to get IRQ for port %d\n", port_num); |
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goto out_close; |
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} |
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*port = ((struct port_list) |
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{ .list = LIST_HEAD_INIT(port->list), |
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.wait_count = ATOMIC_INIT(0), |
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.has_connection = 0, |
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.port = port_num, |
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.fd = fd, |
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.pending = LIST_HEAD_INIT(port->pending), |
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.connections = LIST_HEAD_INIT(port->connections) }); |
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spin_lock_init(&port->lock); |
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init_completion(&port->done); |
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list_add(&port->list, &ports); |
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found: |
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dev = kmalloc(sizeof(struct port_dev), GFP_KERNEL); |
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if (dev == NULL) { |
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printk(KERN_ERR "Allocation of port device entry failed\n"); |
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goto out; |
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} |
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*dev = ((struct port_dev) { .port = port, |
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.helper_pid = -1, |
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.telnetd_pid = -1 }); |
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goto out; |
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out_close: |
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os_close_file(fd); |
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out_free: |
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kfree(port); |
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out: |
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mutex_unlock(&ports_mutex); |
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return dev; |
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} |
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int port_wait(void *data) |
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{ |
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struct port_dev *dev = data; |
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struct connection *conn; |
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struct port_list *port = dev->port; |
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int fd; |
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atomic_inc(&port->wait_count); |
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while (1) { |
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fd = -ERESTARTSYS; |
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if (wait_for_completion_interruptible(&port->done)) |
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goto out; |
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spin_lock(&port->lock); |
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conn = list_entry(port->connections.next, struct connection, |
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list); |
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list_del(&conn->list); |
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spin_unlock(&port->lock); |
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os_shutdown_socket(conn->socket[0], 1, 1); |
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os_close_file(conn->socket[0]); |
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os_shutdown_socket(conn->socket[1], 1, 1); |
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os_close_file(conn->socket[1]); |
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/* This is done here because freeing an IRQ can't be done |
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* within the IRQ handler. So, pipe_interrupt always ups |
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* the semaphore regardless of whether it got a successful |
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* connection. Then we loop here throwing out failed |
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* connections until a good one is found. |
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*/ |
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um_free_irq(TELNETD_IRQ, conn); |
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if (conn->fd >= 0) |
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break; |
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os_close_file(conn->fd); |
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kfree(conn); |
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} |
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fd = conn->fd; |
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dev->helper_pid = conn->helper_pid; |
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dev->telnetd_pid = conn->telnetd_pid; |
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kfree(conn); |
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out: |
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atomic_dec(&port->wait_count); |
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return fd; |
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} |
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void port_remove_dev(void *d) |
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{ |
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struct port_dev *dev = d; |
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if (dev->helper_pid != -1) |
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os_kill_process(dev->helper_pid, 0); |
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if (dev->telnetd_pid != -1) |
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os_kill_process(dev->telnetd_pid, 1); |
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dev->helper_pid = -1; |
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dev->telnetd_pid = -1; |
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} |
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void port_kern_free(void *d) |
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{ |
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struct port_dev *dev = d; |
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port_remove_dev(dev); |
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kfree(dev); |
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} |
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static void free_port(void) |
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{ |
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struct list_head *ele; |
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struct port_list *port; |
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list_for_each(ele, &ports) { |
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port = list_entry(ele, struct port_list, list); |
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free_irq_by_fd(port->fd); |
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os_close_file(port->fd); |
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} |
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} |
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__uml_exitcall(free_port);
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