2 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
3 * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
4 * Licensed under the GPL
7 #include "linux/kernel.h"
8 #include "linux/slab.h"
9 #include "linux/init.h"
10 #include "linux/notifier.h"
11 #include "linux/reboot.h"
12 #include "linux/utsname.h"
13 #include "linux/ctype.h"
14 #include "linux/interrupt.h"
15 #include "linux/sysrq.h"
16 #include "linux/workqueue.h"
17 #include "linux/module.h"
18 #include "linux/file.h"
20 #include "linux/namei.h"
21 #include "linux/proc_fs.h"
23 #include "asm/uaccess.h"
24 #include "user_util.h"
25 #include "kern_util.h"
28 #include "mconsole_kern.h"
35 static int do_unlink_socket(struct notifier_block *notifier,
36 unsigned long what, void *data)
38 return(mconsole_unlink_socket());
42 static struct notifier_block reboot_notifier = {
43 .notifier_call = do_unlink_socket,
47 /* Safe without explicit locking for now. Tasklets provide their own
48 * locking, and the interrupt handler is safe because it can't interrupt
49 * itself and it can only happen on CPU 0.
52 LIST_HEAD(mc_requests);
54 static void mc_work_proc(void *unused)
56 struct mconsole_entry *req;
59 while(!list_empty(&mc_requests)){
60 local_save_flags(flags);
61 req = list_entry(mc_requests.next, struct mconsole_entry,
64 local_irq_restore(flags);
65 req->request.cmd->handler(&req->request);
70 DECLARE_WORK(mconsole_work, mc_work_proc, NULL);
72 static irqreturn_t mconsole_interrupt(int irq, void *dev_id,
76 struct mconsole_entry *new;
77 struct mc_request req;
80 while (mconsole_get_request(fd, &req)){
81 if(req.cmd->context == MCONSOLE_INTR)
82 (*req.cmd->handler)(&req);
84 new = kmalloc(sizeof(*new), GFP_ATOMIC);
86 mconsole_reply(&req, "Out of memory", 1, 0);
89 list_add(&new->list, &mc_requests);
93 if(!list_empty(&mc_requests))
94 schedule_work(&mconsole_work);
95 reactivate_fd(fd, MCONSOLE_IRQ);
99 void mconsole_version(struct mc_request *req)
103 sprintf(version, "%s %s %s %s %s", system_utsname.sysname,
104 system_utsname.nodename, system_utsname.release,
105 system_utsname.version, system_utsname.machine);
106 mconsole_reply(req, version, 0, 0);
109 void mconsole_log(struct mc_request *req)
112 char *ptr = req->request.data;
114 ptr += strlen("log ");
116 len = req->len - (ptr - req->request.data);
117 printk("%.*s", len, ptr);
118 mconsole_reply(req, "", 0, 0);
121 void mconsole_proc(struct mc_request *req)
124 struct file_system_type *proc;
125 struct super_block *super;
128 char *ptr = req->request.data, *buf;
130 ptr += strlen("proc");
131 while(isspace(*ptr)) ptr++;
133 proc = get_fs_type("proc");
135 mconsole_reply(req, "procfs not registered", 1, 0);
139 super = (*proc->get_sb)(proc, 0, NULL, NULL);
140 put_filesystem(proc);
142 mconsole_reply(req, "Failed to get procfs superblock", 1, 0);
145 up_write(&super->s_umount);
147 nd.dentry = super->s_root;
149 nd.flags = O_RDONLY + 1;
150 nd.last_type = LAST_ROOT;
152 err = link_path_walk(ptr, &nd);
154 mconsole_reply(req, "Failed to look up file", 1, 0);
158 file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
160 mconsole_reply(req, "Failed to open file", 1, 0);
164 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
166 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
170 if((file->f_op != NULL) && (file->f_op->read != NULL)){
172 n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1,
176 mconsole_reply(req, buf, 0, (n > 0));
179 mconsole_reply(req, "Read of file failed",
185 else mconsole_reply(req, "", 0, 0);
192 deactivate_super(super);
196 #define UML_MCONSOLE_HELPTEXT \
198 version - Get kernel version \n\
199 help - Print this message \n\
201 reboot - Reboot UML \n\
202 config <dev>=<config> - Add a new device to UML; \n\
203 same syntax as command line \n\
204 config <dev> - Query the configuration of a device \n\
205 remove <dev> - Remove a device from UML \n\
206 sysrq <letter> - Performs the SysRq action controlled by the letter \n\
207 cad - invoke the Ctl-Alt-Del handler \n\
208 stop - pause the UML; it will do nothing until it receives a 'go' \n\
209 go - continue the UML after a 'stop' \n\
210 log <string> - make UML enter <string> into the kernel log\n\
211 proc <file> - returns the contents of the UML's /proc/<file>\n\
214 void mconsole_help(struct mc_request *req)
216 mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
219 void mconsole_halt(struct mc_request *req)
221 mconsole_reply(req, "", 0, 0);
225 void mconsole_reboot(struct mc_request *req)
227 mconsole_reply(req, "", 0, 0);
228 machine_restart(NULL);
231 extern void ctrl_alt_del(void);
233 void mconsole_cad(struct mc_request *req)
235 mconsole_reply(req, "", 0, 0);
239 void mconsole_go(struct mc_request *req)
241 mconsole_reply(req, "Not stopped", 1, 0);
244 void mconsole_stop(struct mc_request *req)
246 deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
247 os_set_fd_block(req->originating_fd, 1);
248 mconsole_reply(req, "", 0, 0);
249 while(mconsole_get_request(req->originating_fd, req)){
250 if(req->cmd->handler == mconsole_go) break;
251 (*req->cmd->handler)(req);
253 os_set_fd_block(req->originating_fd, 0);
254 reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
255 mconsole_reply(req, "", 0, 0);
258 /* This list is populated by __initcall routines. */
260 LIST_HEAD(mconsole_devices);
262 void mconsole_register_dev(struct mc_device *new)
264 list_add(&new->list, &mconsole_devices);
267 static struct mc_device *mconsole_find_dev(char *name)
269 struct list_head *ele;
270 struct mc_device *dev;
272 list_for_each(ele, &mconsole_devices){
273 dev = list_entry(ele, struct mc_device, list);
274 if(!strncmp(name, dev->name, strlen(dev->name)))
280 #define CONFIG_BUF_SIZE 64
282 static void mconsole_get_config(int (*get_config)(char *, char *, int,
284 struct mc_request *req, char *name)
286 char default_buf[CONFIG_BUF_SIZE], *error, *buf;
289 if(get_config == NULL){
290 mconsole_reply(req, "No get_config routine defined", 1, 0);
295 size = sizeof(default_buf)/sizeof(default_buf[0]);
299 n = (*get_config)(name, buf, size, &error);
301 mconsole_reply(req, error, 1, 0);
306 mconsole_reply(req, buf, 0, 0);
310 if(buf != default_buf)
314 buf = kmalloc(size, GFP_KERNEL);
316 mconsole_reply(req, "Failed to allocate buffer", 1, 0);
321 if(buf != default_buf)
326 void mconsole_config(struct mc_request *req)
328 struct mc_device *dev;
329 char *ptr = req->request.data, *name;
332 ptr += strlen("config");
333 while(isspace(*ptr)) ptr++;
334 dev = mconsole_find_dev(ptr);
336 mconsole_reply(req, "Bad configuration option", 1, 0);
340 name = &ptr[strlen(dev->name)];
342 while((*ptr != '=') && (*ptr != '\0'))
346 err = (*dev->config)(name);
347 mconsole_reply(req, "", err, 0);
349 else mconsole_get_config(dev->get_config, req, name);
352 void mconsole_remove(struct mc_request *req)
354 struct mc_device *dev;
355 char *ptr = req->request.data;
358 ptr += strlen("remove");
359 while(isspace(*ptr)) ptr++;
360 dev = mconsole_find_dev(ptr);
362 mconsole_reply(req, "Bad remove option", 1, 0);
365 err = (*dev->remove)(&ptr[strlen(dev->name)]);
366 mconsole_reply(req, "", err, 0);
369 #ifdef CONFIG_MAGIC_SYSRQ
370 void mconsole_sysrq(struct mc_request *req)
372 char *ptr = req->request.data;
374 ptr += strlen("sysrq");
375 while(isspace(*ptr)) ptr++;
377 mconsole_reply(req, "", 0, 0);
378 handle_sysrq(*ptr, ¤t->thread.regs, NULL);
381 void mconsole_sysrq(struct mc_request *req)
383 mconsole_reply(req, "Sysrq not compiled in", 1, 0);
387 /* Changed by mconsole_setup, which is __setup, and called before SMP is
390 static char *notify_socket = NULL;
392 int mconsole_init(void)
397 if(umid_file_name("mconsole", file, sizeof(file))) return(-1);
398 snprintf(mconsole_socket_name, sizeof(file), "%s", file);
400 sock = os_create_unix_socket(file, sizeof(file), 1);
402 printk("Failed to initialize management console\n");
406 register_reboot_notifier(&reboot_notifier);
408 err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
409 SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
410 "mconsole", (void *)sock);
412 printk("Failed to get IRQ for management console\n");
416 if(notify_socket != NULL){
417 notify_socket = uml_strdup(notify_socket);
418 if(notify_socket != NULL)
419 mconsole_notify(notify_socket, MCONSOLE_SOCKET,
420 mconsole_socket_name,
421 strlen(mconsole_socket_name) + 1);
422 else printk(KERN_ERR "mconsole_setup failed to strdup "
426 printk("mconsole (version %d) initialized on %s\n",
427 MCONSOLE_VERSION, mconsole_socket_name);
431 __initcall(mconsole_init);
433 static int write_proc_mconsole(struct file *file, const char *buffer,
434 unsigned long count, void *data)
438 buf = kmalloc(count + 1, GFP_KERNEL);
442 if(copy_from_user(buf, buffer, count)){
449 mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
455 static int create_proc_mconsole(void)
457 struct proc_dir_entry *ent;
459 if(notify_socket == NULL) return(0);
461 ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
463 printk("create_proc_mconsole : create_proc_entry failed\n");
467 ent->read_proc = NULL;
468 ent->write_proc = write_proc_mconsole;
472 static spinlock_t notify_spinlock = SPIN_LOCK_UNLOCKED;
474 void lock_notify(void)
476 spin_lock(¬ify_spinlock);
479 void unlock_notify(void)
481 spin_unlock(¬ify_spinlock);
484 __initcall(create_proc_mconsole);
486 #define NOTIFY "=notify:"
488 static int mconsole_setup(char *str)
490 if(!strncmp(str, NOTIFY, strlen(NOTIFY))){
491 str += strlen(NOTIFY);
494 else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
498 __setup("mconsole", mconsole_setup);
500 __uml_help(mconsole_setup,
501 "mconsole=notify:<socket>\n"
502 " Requests that the mconsole driver send a message to the named Unix\n"
503 " socket containing the name of the mconsole socket. This also serves\n"
504 " to notify outside processes when UML has booted far enough to respond\n"
505 " to mconsole requests.\n\n"
508 static int notify_panic(struct notifier_block *self, unsigned long unused1,
513 if(notify_socket == NULL) return(0);
515 mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
516 strlen(message) + 1);
520 static struct notifier_block panic_exit_notifier = {
521 .notifier_call = notify_panic,
526 static int add_notifier(void)
528 notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
532 __initcall(add_notifier);
534 char *mconsole_notify_socket(void)
536 return(notify_socket);
539 EXPORT_SYMBOL(mconsole_notify_socket);
542 * Overrides for Emacs so that we follow Linus's tabbing style.
543 * Emacs will notice this stuff at the end of the file and automatically
544 * adjust the settings for this buffer only. This must remain at the end
546 * ---------------------------------------------------------------------------
548 * c-file-style: "linux"