blob: 133ccee28a8475a29811eabe79585d5fea9be8c7 [file] [log] [blame]
/*
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
* Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/slab.h"
#include "linux/init.h"
#include "linux/notifier.h"
#include "linux/reboot.h"
#include "linux/utsname.h"
#include "linux/ctype.h"
#include "linux/interrupt.h"
#include "linux/sysrq.h"
#include "linux/tqueue.h"
#include "linux/module.h"
#include "linux/file.h"
#include "linux/fs.h"
#include "linux/proc_fs.h"
#include "asm/irq.h"
#include "asm/uaccess.h"
#include "user_util.h"
#include "kern_util.h"
#include "kern.h"
#include "mconsole.h"
#include "mconsole_kern.h"
#include "irq_user.h"
#include "init.h"
#include "os.h"
#include "umid.h"
#include "irq_kern.h"
static int do_unlink_socket(struct notifier_block *notifier,
unsigned long what, void *data)
{
return(mconsole_unlink_socket());
}
static struct notifier_block reboot_notifier = {
.notifier_call = do_unlink_socket,
.priority = 0,
};
/* Safe without explicit locking for now. Tasklets provide their own
* locking, and the interrupt handler is safe because it can't interrupt
* itself and it can only happen on CPU 0.
*/
LIST_HEAD(mc_requests);
void mc_task_proc(void *unused)
{
struct mconsole_entry *req;
unsigned long flags;
int done;
do {
save_flags(flags);
req = list_entry(mc_requests.next, struct mconsole_entry,
list);
list_del(&req->list);
done = list_empty(&mc_requests);
restore_flags(flags);
req->request.cmd->handler(&req->request);
kfree(req);
} while(!done);
}
struct tq_struct mconsole_task = {
.routine = mc_task_proc,
.data = NULL
};
void mconsole_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
int fd;
struct mconsole_entry *new;
struct mc_request req;
fd = (int) dev_id;
while (mconsole_get_request(fd, &req)){
if(req.cmd->context == MCONSOLE_INTR)
(*req.cmd->handler)(&req);
else {
new = kmalloc(sizeof(*new), GFP_ATOMIC);
if(new == NULL)
mconsole_reply(&req, "Out of memory", 1, 0);
else {
new->request = req;
list_add(&new->list, &mc_requests);
}
}
}
if(!list_empty(&mc_requests))
schedule_task(&mconsole_task);
reactivate_fd(fd, MCONSOLE_IRQ);
}
void mconsole_version(struct mc_request *req)
{
char version[256];
sprintf(version, "%s %s %s %s %s", system_utsname.sysname,
system_utsname.nodename, system_utsname.release,
system_utsname.version, system_utsname.machine);
mconsole_reply(req, version, 0, 0);
}
void mconsole_log(struct mc_request *req)
{
int len;
char *ptr = req->request.data;
ptr += strlen("log ");
len = req->len - (ptr - req->request.data);
printk("%.*s", len, ptr);
mconsole_reply(req, "", 0, 0);
}
void mconsole_proc(struct mc_request *req)
{
struct nameidata nd;
struct file_system_type *proc;
struct super_block *super;
struct file *file;
int n, err;
char *ptr = req->request.data, *buf;
ptr += strlen("proc");
while(isspace(*ptr)) ptr++;
proc = get_fs_type("proc");
if(proc == NULL){
mconsole_reply(req, "procfs not registered", 1, 0);
goto out;
}
super = get_anon_super(proc, NULL, NULL);
if(super == NULL){
mconsole_reply(req, "Failed to get procfs superblock", 1, 0);
goto out_put;
}
if(super->s_root == NULL){
super = (*proc->read_super)(super, NULL, 0);
if(super == NULL){
mconsole_reply(req, "Failed to read superblock", 1, 0);
goto out_put;
}
}
up_write(&super->s_umount);
nd.dentry = super->s_root;
nd.mnt = NULL;
nd.flags = O_RDONLY + 1;
nd.last_type = LAST_ROOT;
err = link_path_walk(ptr, &nd);
if(err){
mconsole_reply(req, "Failed to look up file", 1, 0);
goto out_kill;
}
file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
if(IS_ERR(file)){
mconsole_reply(req, "Failed to open file", 1, 0);
goto out_kill;
}
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if(buf == NULL){
mconsole_reply(req, "Failed to allocate buffer", 1, 0);
goto out_fput;
}
if((file->f_op != NULL) && (file->f_op->read != NULL)){
do {
n = (*file->f_op->read)(file, buf, PAGE_SIZE - 1,
&file->f_pos);
if(n >= 0){
buf[n] = '\0';
mconsole_reply(req, buf, 0, (n > 0));
}
else {
mconsole_reply(req, "Read of file failed",
1, 0);
goto out_free;
}
} while(n > 0);
}
else mconsole_reply(req, "", 0, 0);
out_free:
kfree(buf);
out_fput:
fput(file);
out_kill:
kill_super(super);
out_put:
/* put_filesystem(proc); */
out: ;
}
#define UML_MCONSOLE_HELPTEXT \
"Commands: \n\
version - Get kernel version \n\
help - Print this message \n\
halt - Halt UML \n\
reboot - Reboot UML \n\
config <dev>=<config> - Add a new device to UML; \n\
same syntax as command line \n\
config <dev> - Query the configuration of a device \n\
remove <dev> - Remove a device from UML \n\
sysrq <letter> - Performs the SysRq action controlled by the letter \n\
cad - invoke the Ctl-Alt-Del handler \n\
stop - pause the UML; it will do nothing until it receives a 'go' \n\
go - continue the UML after a 'stop' \n\
log <string> - make UML enter <string> into the kernel log\n\
proc <file> - returns the contents of the UML's /proc/<file>\n\
"
void mconsole_help(struct mc_request *req)
{
mconsole_reply(req, UML_MCONSOLE_HELPTEXT, 0, 0);
}
void mconsole_halt(struct mc_request *req)
{
mconsole_reply(req, "", 0, 0);
machine_halt();
}
void mconsole_reboot(struct mc_request *req)
{
mconsole_reply(req, "", 0, 0);
machine_restart(NULL);
}
extern void ctrl_alt_del(void);
void mconsole_cad(struct mc_request *req)
{
mconsole_reply(req, "", 0, 0);
ctrl_alt_del();
}
void mconsole_go(struct mc_request *req)
{
mconsole_reply(req, "Not stopped", 1, 0);
}
void mconsole_stop(struct mc_request *req)
{
deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
os_set_fd_block(req->originating_fd, 1);
mconsole_reply(req, "", 0, 0);
while(mconsole_get_request(req->originating_fd, req)){
if(req->cmd->handler == mconsole_go) break;
(*req->cmd->handler)(req);
}
os_set_fd_block(req->originating_fd, 0);
reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
mconsole_reply(req, "", 0, 0);
}
/* This list is populated by __initcall routines. */
LIST_HEAD(mconsole_devices);
void mconsole_register_dev(struct mc_device *new)
{
list_add(&new->list, &mconsole_devices);
}
static struct mc_device *mconsole_find_dev(char *name)
{
struct list_head *ele;
struct mc_device *dev;
list_for_each(ele, &mconsole_devices){
dev = list_entry(ele, struct mc_device, list);
if(!strncmp(name, dev->name, strlen(dev->name)))
return(dev);
}
return(NULL);
}
#define CONFIG_BUF_SIZE 64
static void mconsole_get_config(int (*get_config)(char *, char *, int,
char **),
struct mc_request *req, char *name)
{
char default_buf[CONFIG_BUF_SIZE], *error, *buf;
int n, size;
if(get_config == NULL){
mconsole_reply(req, "No get_config routine defined", 1, 0);
return;
}
error = NULL;
size = sizeof(default_buf)/sizeof(default_buf[0]);
buf = default_buf;
while(1){
n = (*get_config)(name, buf, size, &error);
if(error != NULL){
mconsole_reply(req, error, 1, 0);
goto out;
}
if(n <= size){
mconsole_reply(req, buf, 0, 0);
goto out;
}
if(buf != default_buf)
kfree(buf);
size = n;
buf = kmalloc(size, GFP_KERNEL);
if(buf == NULL){
mconsole_reply(req, "Failed to allocate buffer", 1, 0);
return;
}
}
out:
if(buf != default_buf)
kfree(buf);
}
void mconsole_config(struct mc_request *req)
{
struct mc_device *dev;
char *ptr = req->request.data, *name;
int err;
ptr += strlen("config");
while(isspace(*ptr)) ptr++;
dev = mconsole_find_dev(ptr);
if(dev == NULL){
mconsole_reply(req, "Bad configuration option", 1, 0);
return;
}
name = &ptr[strlen(dev->name)];
ptr = name;
while((*ptr != '=') && (*ptr != '\0'))
ptr++;
if(*ptr == '='){
err = (*dev->config)(name);
mconsole_reply(req, "", err, 0);
}
else mconsole_get_config(dev->get_config, req, name);
}
void mconsole_remove(struct mc_request *req)
{
struct mc_device *dev;
char *ptr = req->request.data;
int err;
ptr += strlen("remove");
while(isspace(*ptr)) ptr++;
dev = mconsole_find_dev(ptr);
if(dev == NULL){
mconsole_reply(req, "Bad remove option", 1, 0);
return;
}
err = (*dev->remove)(&ptr[strlen(dev->name)]);
mconsole_reply(req, "", err, 0);
}
#ifdef CONFIG_MAGIC_SYSRQ
void mconsole_sysrq(struct mc_request *req)
{
char *ptr = req->request.data;
ptr += strlen("sysrq");
while(isspace(*ptr)) ptr++;
mconsole_reply(req, "", 0, 0);
handle_sysrq(*ptr, &current->thread.regs, NULL, NULL);
}
#else
void mconsole_sysrq(struct mc_request *req)
{
mconsole_reply(req, "Sysrq not compiled in", 1, 0);
}
#endif
/* Changed by mconsole_setup, which is __setup, and called before SMP is
* active.
*/
static char *notify_socket = NULL;
int mconsole_init(void)
{
int err, sock;
char file[256];
if(umid_file_name("mconsole", file, sizeof(file))) return(-1);
snprintf(mconsole_socket_name, sizeof(file), "%s", file);
sock = os_create_unix_socket(file, sizeof(file), 1);
if (sock < 0){
printk("Failed to initialize management console\n");
return(1);
}
register_reboot_notifier(&reboot_notifier);
err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
"mconsole", (void *)sock);
if (err){
printk("Failed to get IRQ for management console\n");
return(1);
}
if(notify_socket != NULL){
notify_socket = uml_strdup(notify_socket);
if(notify_socket != NULL)
mconsole_notify(notify_socket, MCONSOLE_SOCKET,
mconsole_socket_name,
strlen(mconsole_socket_name) + 1);
else printk(KERN_ERR "mconsole_setup failed to strdup "
"string\n");
}
printk("mconsole (version %d) initialized on %s\n",
MCONSOLE_VERSION, mconsole_socket_name);
return(0);
}
__initcall(mconsole_init);
static int write_proc_mconsole(struct file *file, const char *buffer,
unsigned long count, void *data)
{
char *buf;
buf = kmalloc(count + 1, GFP_KERNEL);
if(buf == NULL)
return(-ENOMEM);
if(copy_from_user(buf, buffer, count)){
count = -EFAULT;
goto out;
}
buf[count] = '\0';
mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
out:
kfree(buf);
return(count);
}
static int create_proc_mconsole(void)
{
struct proc_dir_entry *ent;
if(notify_socket == NULL) return(0);
ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL);
if(ent == NULL){
printk("create_proc_mconsole : create_proc_entry failed\n");
return(0);
}
ent->read_proc = NULL;
ent->write_proc = write_proc_mconsole;
return(0);
}
static spinlock_t notify_spinlock = SPIN_LOCK_UNLOCKED;
void lock_notify(void)
{
spin_lock(&notify_spinlock);
}
void unlock_notify(void)
{
spin_unlock(&notify_spinlock);
}
__initcall(create_proc_mconsole);
#define NOTIFY "=notify:"
static int mconsole_setup(char *str)
{
if(!strncmp(str, NOTIFY, strlen(NOTIFY))){
str += strlen(NOTIFY);
notify_socket = str;
}
else printk(KERN_ERR "mconsole_setup : Unknown option - '%s'\n", str);
return(1);
}
__setup("mconsole", mconsole_setup);
__uml_help(mconsole_setup,
"mconsole=notify:<socket>\n"
" Requests that the mconsole driver send a message to the named Unix\n"
" socket containing the name of the mconsole socket. This also serves\n"
" to notify outside processes when UML has booted far enough to respond\n"
" to mconsole requests.\n\n"
);
static int notify_panic(struct notifier_block *self, unsigned long unused1,
void *ptr)
{
char *message = ptr;
if(notify_socket == NULL) return(0);
mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
strlen(message) + 1);
return(0);
}
static struct notifier_block panic_exit_notifier = {
.notifier_call = notify_panic,
.next = NULL,
.priority = 1
};
static int add_notifier(void)
{
notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
return(0);
}
__initcall(add_notifier);
char *mconsole_notify_socket(void)
{
return(notify_socket);
}
EXPORT_SYMBOL(mconsole_notify_socket);
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/