Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com) | |
3 | * Licensed under the GPL | |
4 | */ | |
5 | ||
6 | #include "linux/list.h" | |
7 | #include "linux/sched.h" | |
8 | #include "linux/slab.h" | |
9 | #include "linux/interrupt.h" | |
10 | #include "linux/irq.h" | |
11 | #include "linux/spinlock.h" | |
12 | #include "linux/errno.h" | |
13 | #include "asm/atomic.h" | |
14 | #include "asm/semaphore.h" | |
15 | #include "asm/errno.h" | |
16 | #include "kern_util.h" | |
17 | #include "kern.h" | |
18 | #include "irq_user.h" | |
19 | #include "irq_kern.h" | |
20 | #include "port.h" | |
21 | #include "init.h" | |
22 | #include "os.h" | |
23 | ||
24 | struct port_list { | |
25 | struct list_head list; | |
26 | atomic_t wait_count; | |
27 | int has_connection; | |
28 | struct completion done; | |
29 | int port; | |
30 | int fd; | |
31 | spinlock_t lock; | |
32 | struct list_head pending; | |
33 | struct list_head connections; | |
34 | }; | |
35 | ||
36 | struct port_dev { | |
37 | struct port_list *port; | |
38 | int helper_pid; | |
39 | int telnetd_pid; | |
40 | }; | |
41 | ||
42 | struct connection { | |
43 | struct list_head list; | |
44 | int fd; | |
45 | int helper_pid; | |
46 | int socket[2]; | |
47 | int telnetd_pid; | |
48 | struct port_list *port; | |
49 | }; | |
50 | ||
51 | static irqreturn_t pipe_interrupt(int irq, void *data, struct pt_regs *regs) | |
52 | { | |
53 | struct connection *conn = data; | |
54 | int fd; | |
55 | ||
56 | fd = os_rcv_fd(conn->socket[0], &conn->helper_pid); | |
57 | if(fd < 0){ | |
58 | if(fd == -EAGAIN) | |
59 | return(IRQ_NONE); | |
60 | ||
61 | printk(KERN_ERR "pipe_interrupt : os_rcv_fd returned %d\n", | |
62 | -fd); | |
63 | os_close_file(conn->fd); | |
64 | } | |
65 | ||
66 | list_del(&conn->list); | |
67 | ||
68 | conn->fd = fd; | |
69 | list_add(&conn->list, &conn->port->connections); | |
70 | ||
71 | complete(&conn->port->done); | |
72 | return(IRQ_HANDLED); | |
73 | } | |
74 | ||
75 | #define NO_WAITER_MSG \ | |
76 | "****\n" \ | |
77 | "There are currently no UML consoles waiting for port connections.\n" \ | |
78 | "Either disconnect from one to make it available or activate some more\n" \ | |
79 | "by enabling more consoles in the UML /etc/inittab.\n" \ | |
80 | "****\n" | |
81 | ||
82 | static int port_accept(struct port_list *port) | |
83 | { | |
84 | struct connection *conn; | |
85 | int fd, socket[2], pid, ret = 0; | |
86 | ||
87 | fd = port_connection(port->fd, socket, &pid); | |
88 | if(fd < 0){ | |
89 | if(fd != -EAGAIN) | |
90 | printk(KERN_ERR "port_accept : port_connection " | |
91 | "returned %d\n", -fd); | |
92 | goto out; | |
93 | } | |
94 | ||
95 | conn = kmalloc(sizeof(*conn), GFP_ATOMIC); | |
96 | if(conn == NULL){ | |
97 | printk(KERN_ERR "port_accept : failed to allocate " | |
98 | "connection\n"); | |
99 | goto out_close; | |
100 | } | |
101 | *conn = ((struct connection) | |
102 | { .list = LIST_HEAD_INIT(conn->list), | |
103 | .fd = fd, | |
104 | .socket = { socket[0], socket[1] }, | |
105 | .telnetd_pid = pid, | |
106 | .port = port }); | |
107 | ||
108 | if(um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt, | |
109 | SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, | |
110 | "telnetd", conn)){ | |
111 | printk(KERN_ERR "port_accept : failed to get IRQ for " | |
112 | "telnetd\n"); | |
113 | goto out_free; | |
114 | } | |
115 | ||
116 | if(atomic_read(&port->wait_count) == 0){ | |
117 | os_write_file(fd, NO_WAITER_MSG, sizeof(NO_WAITER_MSG)); | |
118 | printk("No one waiting for port\n"); | |
119 | } | |
120 | list_add(&conn->list, &port->pending); | |
121 | return(1); | |
122 | ||
123 | out_free: | |
124 | kfree(conn); | |
125 | out_close: | |
126 | os_close_file(fd); | |
127 | if(pid != -1) | |
128 | os_kill_process(pid, 1); | |
129 | out: | |
130 | return(ret); | |
131 | } | |
132 | ||
133 | DECLARE_MUTEX(ports_sem); | |
134 | struct list_head ports = LIST_HEAD_INIT(ports); | |
135 | ||
136 | void port_work_proc(void *unused) | |
137 | { | |
138 | struct port_list *port; | |
139 | struct list_head *ele; | |
140 | unsigned long flags; | |
141 | ||
142 | local_irq_save(flags); | |
143 | list_for_each(ele, &ports){ | |
144 | port = list_entry(ele, struct port_list, list); | |
145 | if(!port->has_connection) | |
146 | continue; | |
147 | reactivate_fd(port->fd, ACCEPT_IRQ); | |
148 | while(port_accept(port)) ; | |
149 | port->has_connection = 0; | |
150 | } | |
151 | local_irq_restore(flags); | |
152 | } | |
153 | ||
154 | DECLARE_WORK(port_work, port_work_proc, NULL); | |
155 | ||
156 | static irqreturn_t port_interrupt(int irq, void *data, struct pt_regs *regs) | |
157 | { | |
158 | struct port_list *port = data; | |
159 | ||
160 | port->has_connection = 1; | |
161 | schedule_work(&port_work); | |
162 | return(IRQ_HANDLED); | |
163 | } | |
164 | ||
165 | void *port_data(int port_num) | |
166 | { | |
167 | struct list_head *ele; | |
168 | struct port_list *port; | |
169 | struct port_dev *dev = NULL; | |
170 | int fd; | |
171 | ||
172 | down(&ports_sem); | |
173 | list_for_each(ele, &ports){ | |
174 | port = list_entry(ele, struct port_list, list); | |
175 | if(port->port == port_num) goto found; | |
176 | } | |
177 | port = kmalloc(sizeof(struct port_list), GFP_KERNEL); | |
178 | if(port == NULL){ | |
179 | printk(KERN_ERR "Allocation of port list failed\n"); | |
180 | goto out; | |
181 | } | |
182 | ||
183 | fd = port_listen_fd(port_num); | |
184 | if(fd < 0){ | |
185 | printk(KERN_ERR "binding to port %d failed, errno = %d\n", | |
186 | port_num, -fd); | |
187 | goto out_free; | |
188 | } | |
189 | if(um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt, | |
190 | SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, "port", | |
191 | port)){ | |
192 | printk(KERN_ERR "Failed to get IRQ for port %d\n", port_num); | |
193 | goto out_close; | |
194 | } | |
195 | ||
196 | *port = ((struct port_list) | |
197 | { .list = LIST_HEAD_INIT(port->list), | |
198 | .wait_count = ATOMIC_INIT(0), | |
199 | .has_connection = 0, | |
200 | .port = port_num, | |
201 | .fd = fd, | |
202 | .pending = LIST_HEAD_INIT(port->pending), | |
203 | .connections = LIST_HEAD_INIT(port->connections) }); | |
204 | spin_lock_init(&port->lock); | |
205 | init_completion(&port->done); | |
206 | list_add(&port->list, &ports); | |
207 | ||
208 | found: | |
209 | dev = kmalloc(sizeof(struct port_dev), GFP_KERNEL); | |
210 | if(dev == NULL){ | |
211 | printk(KERN_ERR "Allocation of port device entry failed\n"); | |
212 | goto out; | |
213 | } | |
214 | ||
215 | *dev = ((struct port_dev) { .port = port, | |
216 | .helper_pid = -1, | |
217 | .telnetd_pid = -1 }); | |
218 | goto out; | |
219 | ||
220 | out_free: | |
221 | kfree(port); | |
222 | out_close: | |
223 | os_close_file(fd); | |
224 | out: | |
225 | up(&ports_sem); | |
226 | return(dev); | |
227 | } | |
228 | ||
229 | int port_wait(void *data) | |
230 | { | |
231 | struct port_dev *dev = data; | |
232 | struct connection *conn; | |
233 | struct port_list *port = dev->port; | |
234 | int fd; | |
235 | ||
236 | atomic_inc(&port->wait_count); | |
237 | while(1){ | |
238 | fd = -ERESTARTSYS; | |
239 | if(wait_for_completion_interruptible(&port->done)) | |
240 | goto out; | |
241 | ||
242 | spin_lock(&port->lock); | |
243 | ||
244 | conn = list_entry(port->connections.next, struct connection, | |
245 | list); | |
246 | list_del(&conn->list); | |
247 | spin_unlock(&port->lock); | |
248 | ||
249 | os_shutdown_socket(conn->socket[0], 1, 1); | |
250 | os_close_file(conn->socket[0]); | |
251 | os_shutdown_socket(conn->socket[1], 1, 1); | |
252 | os_close_file(conn->socket[1]); | |
253 | ||
254 | /* This is done here because freeing an IRQ can't be done | |
255 | * within the IRQ handler. So, pipe_interrupt always ups | |
256 | * the semaphore regardless of whether it got a successful | |
257 | * connection. Then we loop here throwing out failed | |
258 | * connections until a good one is found. | |
259 | */ | |
260 | free_irq_by_irq_and_dev(TELNETD_IRQ, conn); | |
261 | free_irq(TELNETD_IRQ, conn); | |
262 | ||
263 | if(conn->fd >= 0) break; | |
264 | os_close_file(conn->fd); | |
265 | kfree(conn); | |
266 | } | |
267 | ||
268 | fd = conn->fd; | |
269 | dev->helper_pid = conn->helper_pid; | |
270 | dev->telnetd_pid = conn->telnetd_pid; | |
271 | kfree(conn); | |
272 | out: | |
273 | atomic_dec(&port->wait_count); | |
274 | return fd; | |
275 | } | |
276 | ||
277 | void port_remove_dev(void *d) | |
278 | { | |
279 | struct port_dev *dev = d; | |
280 | ||
281 | if(dev->helper_pid != -1) | |
282 | os_kill_process(dev->helper_pid, 0); | |
283 | if(dev->telnetd_pid != -1) | |
284 | os_kill_process(dev->telnetd_pid, 1); | |
285 | dev->helper_pid = -1; | |
286 | dev->telnetd_pid = -1; | |
287 | } | |
288 | ||
289 | void port_kern_free(void *d) | |
290 | { | |
291 | struct port_dev *dev = d; | |
292 | ||
293 | port_remove_dev(dev); | |
294 | kfree(dev); | |
295 | } | |
296 | ||
297 | static void free_port(void) | |
298 | { | |
299 | struct list_head *ele; | |
300 | struct port_list *port; | |
301 | ||
302 | list_for_each(ele, &ports){ | |
303 | port = list_entry(ele, struct port_list, list); | |
304 | free_irq_by_fd(port->fd); | |
305 | os_close_file(port->fd); | |
306 | } | |
307 | } | |
308 | ||
309 | __uml_exitcall(free_port); |