[mirror_ubuntu-bionic-kernel.git] / arch / um / kernel / umid.c

/* 
 * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/param.h>
#include "user.h"
#include "umid.h"
#include "init.h"
#include "os.h"
#include "user_util.h"
#include "choose-mode.h"

#define UMID_LEN 64
#define UML_DIR "~/.uml/"

/* Changed by set_umid and make_umid, which are run early in boot */
static char umid[UMID_LEN] = { 0 };

/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
static char *uml_dir = UML_DIR;

/* Changed by set_umid */
static int umid_is_random = 1;
static int umid_inited = 0;
/* Have we created the files? Should we remove them? */
static int umid_owned = 0;

static int make_umid(int (*printer)(const char *fmt, ...));

static int __init set_umid(char *name, int is_random,
			   int (*printer)(const char *fmt, ...))
{
	if(umid_inited){
		(*printer)("Unique machine name can't be set twice\n");
		return(-1);
	}

	if(strlen(name) > UMID_LEN - 1)
		(*printer)("Unique machine name is being truncated to %d "
			   "characters\n", UMID_LEN);
	strlcpy(umid, name, sizeof(umid));

	umid_is_random = is_random;
	umid_inited = 1;
	return 0;
}

static int __init set_umid_arg(char *name, int *add)
{
	*add = 0;
	return(set_umid(name, 0, printf));
}

__uml_setup("umid=", set_umid_arg,
"umid=<name>\n"
"    This is used to assign a unique identity to this UML machine and\n"
"    is used for naming the pid file and management console socket.\n\n"
);

int __init umid_file_name(char *name, char *buf, int len)
{
	int n;

	if(!umid_inited && make_umid(printk)) return(-1);

	n = strlen(uml_dir) + strlen(umid) + strlen(name) + 1;
	if(n > len){
		printk("umid_file_name : buffer too short\n");
		return(-1);
	}

	sprintf(buf, "%s%s/%s", uml_dir, umid, name);
	return(0);
}

extern int tracing_pid;

static void __init create_pid_file(void)
{
	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	char pid[sizeof("nnnnn\0")];
	int fd, n;

	if(umid_file_name("pid", file, sizeof(file)))
		return;

	fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))), 
			  0644);
	if(fd < 0){
		printf("Open of machine pid file \"%s\" failed: %s\n",
		       file, strerror(-fd));
		return;
	}

	sprintf(pid, "%d\n", os_getpid());
	n = os_write_file(fd, pid, strlen(pid));
	if(n != strlen(pid))
		printf("Write of pid file failed - err = %d\n", -n);
	os_close_file(fd);
}

static int actually_do_remove(char *dir)
{
	DIR *directory;
	struct dirent *ent;
	int len;
	char file[256];

	directory = opendir(dir);
	if(directory == NULL){
		printk("actually_do_remove : couldn't open directory '%s', "
		       "errno = %d\n", dir, errno);
		return(1);
	}
	while((ent = readdir(directory)) != NULL){
		if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
			continue;
		len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
		if(len > sizeof(file)){
			printk("Not deleting '%s' from '%s' - name too long\n",
			       ent->d_name, dir);
			continue;
		}
		sprintf(file, "%s/%s", dir, ent->d_name);
		if(unlink(file) < 0){
			printk("actually_do_remove : couldn't remove '%s' "
			       "from '%s', errno = %d\n", ent->d_name, dir, 
			       errno);
			return(1);
		}
	}
	if(rmdir(dir) < 0){
		printk("actually_do_remove : couldn't rmdir '%s', "
		       "errno = %d\n", dir, errno);
		return(1);
	}
	return(0);
}

void remove_umid_dir(void)
{
	char dir[strlen(uml_dir) + UMID_LEN + 1];
	if (!umid_owned)
		return;

	sprintf(dir, "%s%s", uml_dir, umid);
	actually_do_remove(dir);
}

char *get_umid(int only_if_set)
{
	if(only_if_set && umid_is_random)
		return NULL;
	return umid;
}

static int not_dead_yet(char *dir)
{
	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	char pid[sizeof("nnnnn\0")], *end;
	int dead, fd, p, n;

	sprintf(file, "%s/pid", dir);
	dead = 0;
	fd = os_open_file(file, of_read(OPENFLAGS()), 0);
	if(fd < 0){
		if(fd != -ENOENT){
			printk("not_dead_yet : couldn't open pid file '%s', "
			       "err = %d\n", file, -fd);
			return(1);
		}
		dead = 1;
	}
	if(fd > 0){
		n = os_read_file(fd, pid, sizeof(pid));
		if(n < 0){
			printk("not_dead_yet : couldn't read pid file '%s', "
			       "err = %d\n", file, -n);
			return(1);
		}
		p = strtoul(pid, &end, 0);
		if(end == pid){
			printk("not_dead_yet : couldn't parse pid file '%s', "
			       "errno = %d\n", file, errno);
			dead = 1;
		}
		if(((kill(p, 0) < 0) && (errno == ESRCH)) ||
		   (p == CHOOSE_MODE(tracing_pid, os_getpid())))
			dead = 1;
	}
	if(!dead)
		return(1);
	return(actually_do_remove(dir));
}

static int __init set_uml_dir(char *name, int *add)
{
	if((strlen(name) > 0) && (name[strlen(name) - 1] != '/')){
		uml_dir = malloc(strlen(name) + 2);
		if(uml_dir == NULL){
			printf("Failed to malloc uml_dir - error = %d\n",
			       errno);
			uml_dir = name;
			/* Return 0 here because do_initcalls doesn't look at
			 * the return value.
			 */
			return(0);
		}
		sprintf(uml_dir, "%s/", name);
	}
	else uml_dir = name;
	return(0);
}

static int __init make_uml_dir(void)
{
	char dir[MAXPATHLEN + 1] = { '\0' };
	int len;

	if(*uml_dir == '~'){
		char *home = getenv("HOME");

		if(home == NULL){
			printf("make_uml_dir : no value in environment for "
			       "$HOME\n");
			exit(1);
		}
		strlcpy(dir, home, sizeof(dir));
		uml_dir++;
	}
	strlcat(dir, uml_dir, sizeof(dir));
	len = strlen(dir);
	if (len > 0 && dir[len - 1] != '/')
		strlcat(dir, "/", sizeof(dir));

	uml_dir = malloc(strlen(dir) + 1);
	if (uml_dir == NULL) {
		printf("make_uml_dir : malloc failed, errno = %d\n", errno);
		exit(1);
	}
	strcpy(uml_dir, dir);
	
	if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){
	        printf("Failed to mkdir %s: %s\n", uml_dir, strerror(errno));
		return(-1);
	}
	return 0;
}

static int __init make_umid(int (*printer)(const char *fmt, ...))
{
	int fd, err;
	char tmp[strlen(uml_dir) + UMID_LEN + 1];

	strlcpy(tmp, uml_dir, sizeof(tmp));

	if(!umid_inited){
		strcat(tmp, "XXXXXX");
		fd = mkstemp(tmp);
		if(fd < 0){
			(*printer)("make_umid - mkstemp(%s) failed: %s\n",
				   tmp,strerror(errno));
			return(1);
		}

		os_close_file(fd);
		/* There's a nice tiny little race between this unlink and
		 * the mkdir below.  It'd be nice if there were a mkstemp
		 * for directories.
		 */
		unlink(tmp);
		set_umid(&tmp[strlen(uml_dir)], 1, printer);
	}
	
	sprintf(tmp, "%s%s", uml_dir, umid);

	err = mkdir(tmp, 0777);
	if(err < 0){
		if(errno == EEXIST){
			if(not_dead_yet(tmp)){
				(*printer)("umid '%s' is in use\n", umid);
				umid_owned = 0;
				return(-1);
			}
			err = mkdir(tmp, 0777);
		}
	}
	if(err < 0){
		(*printer)("Failed to create %s - errno = %d\n", umid, errno);
		return(-1);
	}

	umid_owned = 1;
	return 0;
}

__uml_setup("uml_dir=", set_uml_dir,
"uml_dir=<directory>\n"
"    The location to place the pid and umid files.\n\n"
);

static int __init make_umid_setup(void)
{
	/* one function with the ordering we need ... */
	make_uml_dir();
	make_umid(printf);
	create_pid_file();
	return 0;
}
__uml_postsetup(make_umid_setup);

/*
 * 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:
 */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
	3	* Licensed under the GPL
	4	*/
	5
	6	#include <stdio.h>
	7	#include <unistd.h>
	8	#include <errno.h>
	9	#include <string.h>
	10	#include <stdlib.h>
	11	#include <dirent.h>
	12	#include <signal.h>
	13	#include <sys/stat.h>
	14	#include <sys/param.h>
	15	#include "user.h"
	16	#include "umid.h"
	17	#include "init.h"
	18	#include "os.h"
	19	#include "user_util.h"
	20	#include "choose-mode.h"
	21
	22	#define UMID_LEN 64
	23	#define UML_DIR "~/.uml/"
	24
	25	/* Changed by set_umid and make_umid, which are run early in boot */
	26	static char umid[UMID_LEN] = { 0 };
	27
	28	/* Changed by set_uml_dir and make_uml_dir, which are run early in boot */
	29	static char *uml_dir = UML_DIR;
	30
	31	/* Changed by set_umid */
	32	static int umid_is_random = 1;
	33	static int umid_inited = 0;
3a02d6c0 PBG	34	/* Have we created the files? Should we remove them? */
3a02d6c0 PBG	35	static int umid_owned = 0;
1da177e4 LT	36
	37	static int make_umid(int (printer)(const char fmt, ...));
	38
	39	static int __init set_umid(char *name, int is_random,
	40	int (printer)(const char fmt, ...))
	41	{
	42	if(umid_inited){
	43	(*printer)("Unique machine name can't be set twice\n");
	44	return(-1);
	45	}
	46
	47	if(strlen(name) > UMID_LEN - 1)
	48	(*printer)("Unique machine name is being truncated to %d "
	49	"characters\n", UMID_LEN);
	50	strlcpy(umid, name, sizeof(umid));
	51
	52	umid_is_random = is_random;
	53	umid_inited = 1;
	54	return 0;
	55	}
	56
	57	static int __init set_umid_arg(char name, int add)
	58	{
	59	*add = 0;
	60	return(set_umid(name, 0, printf));
	61	}
	62
	63	__uml_setup("umid=", set_umid_arg,
	64	"umid=<name>\n"
	65	" This is used to assign a unique identity to this UML machine and\n"
	66	" is used for naming the pid file and management console socket.\n\n"
	67	);
	68
	69	int __init umid_file_name(char name, char buf, int len)
	70	{
	71	int n;
	72
	73	if(!umid_inited && make_umid(printk)) return(-1);
	74
	75	n = strlen(uml_dir) + strlen(umid) + strlen(name) + 1;
	76	if(n > len){
	77	printk("umid_file_name : buffer too short\n");
	78	return(-1);
	79	}
	80
	81	sprintf(buf, "%s%s/%s", uml_dir, umid, name);
	82	return(0);
	83	}
	84
	85	extern int tracing_pid;
	86
3a02d6c0	87	static void __init create_pid_file(void)
1da177e4 LT	88	{
	89	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	90	char pid[sizeof("nnnnn\0")];
	91	int fd, n;
	92
3a02d6c0 PBG	93	if(umid_file_name("pid", file, sizeof(file)))
3a02d6c0 PBG	94	return;
1da177e4 LT	95
	96	fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))),
	97	0644);
	98	if(fd < 0){
	99	printf("Open of machine pid file \"%s\" failed: %s\n",
	100	file, strerror(-fd));
3a02d6c0	101	return;
1da177e4 LT	102	}
	103
	104	sprintf(pid, "%d\n", os_getpid());
	105	n = os_write_file(fd, pid, strlen(pid));
	106	if(n != strlen(pid))
	107	printf("Write of pid file failed - err = %d\n", -n);
	108	os_close_file(fd);
1da177e4 LT	109	}
	110
	111	static int actually_do_remove(char *dir)
	112	{
	113	DIR *directory;
	114	struct dirent *ent;
	115	int len;
	116	char file[256];
	117
	118	directory = opendir(dir);
	119	if(directory == NULL){
	120	printk("actually_do_remove : couldn't open directory '%s', "
	121	"errno = %d\n", dir, errno);
	122	return(1);
	123	}
	124	while((ent = readdir(directory)) != NULL){
	125	if(!strcmp(ent->d_name, ".") \|\| !strcmp(ent->d_name, ".."))
	126	continue;
	127	len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
	128	if(len > sizeof(file)){
	129	printk("Not deleting '%s' from '%s' - name too long\n",
	130	ent->d_name, dir);
	131	continue;
	132	}
	133	sprintf(file, "%s/%s", dir, ent->d_name);
	134	if(unlink(file) < 0){
	135	printk("actually_do_remove : couldn't remove '%s' "
	136	"from '%s', errno = %d\n", ent->d_name, dir,
	137	errno);
	138	return(1);
	139	}
	140	}
	141	if(rmdir(dir) < 0){
	142	printk("actually_do_remove : couldn't rmdir '%s', "
	143	"errno = %d\n", dir, errno);
	144	return(1);
	145	}
	146	return(0);
	147	}
	148
	149	void remove_umid_dir(void)
	150	{
	151	char dir[strlen(uml_dir) + UMID_LEN + 1];
3a02d6c0 PBG	152	if (!umid_owned)
3a02d6c0 PBG	153	return;
1da177e4 LT	154
	155	sprintf(dir, "%s%s", uml_dir, umid);
	156	actually_do_remove(dir);
	157	}
	158
	159	char *get_umid(int only_if_set)
	160	{
3a02d6c0 PBG	161	if(only_if_set && umid_is_random)
	162	return NULL;
	163	return umid;
1da177e4 LT	164	}
1da177e4 LT	165
3a02d6c0	166	static int not_dead_yet(char *dir)
1da177e4 LT	167	{
	168	char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
	169	char pid[sizeof("nnnnn\0")], *end;
	170	int dead, fd, p, n;
	171
	172	sprintf(file, "%s/pid", dir);
	173	dead = 0;
	174	fd = os_open_file(file, of_read(OPENFLAGS()), 0);
	175	if(fd < 0){
	176	if(fd != -ENOENT){
	177	printk("not_dead_yet : couldn't open pid file '%s', "
	178	"err = %d\n", file, -fd);
	179	return(1);
	180	}
	181	dead = 1;
	182	}
	183	if(fd > 0){
	184	n = os_read_file(fd, pid, sizeof(pid));
	185	if(n < 0){
	186	printk("not_dead_yet : couldn't read pid file '%s', "
	187	"err = %d\n", file, -n);
	188	return(1);
	189	}
	190	p = strtoul(pid, &end, 0);
	191	if(end == pid){
	192	printk("not_dead_yet : couldn't parse pid file '%s', "
	193	"errno = %d\n", file, errno);
	194	dead = 1;
	195	}
	196	if(((kill(p, 0) < 0) && (errno == ESRCH)) \|\|
	197	(p == CHOOSE_MODE(tracing_pid, os_getpid())))
	198	dead = 1;
	199	}
3a02d6c0 PBG	200	if(!dead)
3a02d6c0 PBG	201	return(1);
1da177e4 LT	202	return(actually_do_remove(dir));
	203	}
	204
	205	static int __init set_uml_dir(char name, int add)
	206	{
	207	if((strlen(name) > 0) && (name[strlen(name) - 1] != '/')){
	208	uml_dir = malloc(strlen(name) + 2);
	209	if(uml_dir == NULL){
	210	printf("Failed to malloc uml_dir - error = %d\n",
	211	errno);
	212	uml_dir = name;
	213	/* Return 0 here because do_initcalls doesn't look at
	214	* the return value.
	215	*/
	216	return(0);
	217	}
	218	sprintf(uml_dir, "%s/", name);
	219	}
	220	else uml_dir = name;
	221	return(0);
	222	}
	223
	224	static int __init make_uml_dir(void)
	225	{
	226	char dir[MAXPATHLEN + 1] = { '\0' };
	227	int len;
	228
	229	if(*uml_dir == '~'){
	230	char *home = getenv("HOME");
	231
	232	if(home == NULL){
	233	printf("make_uml_dir : no value in environment for "
	234	"$HOME\n");
	235	exit(1);
	236	}
	237	strlcpy(dir, home, sizeof(dir));
	238	uml_dir++;
	239	}
a8bfb94c	240	strlcat(dir, uml_dir, sizeof(dir));
1da177e4	241	len = strlen(dir);
a8bfb94c PBG	242	if (len > 0 && dir[len - 1] != '/')
a8bfb94c PBG	243	strlcat(dir, "/", sizeof(dir));
1da177e4 LT	244
1da177e4 LT	245	uml_dir = malloc(strlen(dir) + 1);
a8bfb94c	246	if (uml_dir == NULL) {
1da177e4 LT	247	printf("make_uml_dir : malloc failed, errno = %d\n", errno);
	248	exit(1);
	249	}
	250	strcpy(uml_dir, dir);
	251
	252	if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){
	253	printf("Failed to mkdir %s: %s\n", uml_dir, strerror(errno));
	254	return(-1);
	255	}
	256	return 0;
	257	}
	258
	259	static int __init make_umid(int (printer)(const char fmt, ...))
	260	{
	261	int fd, err;
	262	char tmp[strlen(uml_dir) + UMID_LEN + 1];
	263
	264	strlcpy(tmp, uml_dir, sizeof(tmp));
	265
	266	if(!umid_inited){
	267	strcat(tmp, "XXXXXX");
	268	fd = mkstemp(tmp);
	269	if(fd < 0){
	270	(*printer)("make_umid - mkstemp(%s) failed: %s\n",
	271	tmp,strerror(errno));
	272	return(1);
	273	}
	274
	275	os_close_file(fd);
	276	/* There's a nice tiny little race between this unlink and
	277	* the mkdir below. It'd be nice if there were a mkstemp
	278	* for directories.
	279	*/
	280	unlink(tmp);
	281	set_umid(&tmp[strlen(uml_dir)], 1, printer);
	282	}
	283
	284	sprintf(tmp, "%s%s", uml_dir, umid);
	285
	286	err = mkdir(tmp, 0777);
	287	if(err < 0){
	288	if(errno == EEXIST){
	289	if(not_dead_yet(tmp)){
	290	(*printer)("umid '%s' is in use\n", umid);
3a02d6c0	291	umid_owned = 0;
1da177e4 LT	292	return(-1);
	293	}
	294	err = mkdir(tmp, 0777);
	295	}
	296	}
	297	if(err < 0){
	298	(*printer)("Failed to create %s - errno = %d\n", umid, errno);
	299	return(-1);
	300	}
	301
3a02d6c0 PBG	302	umid_owned = 1;
3a02d6c0 PBG	303	return 0;
1da177e4 LT	304	}
	305
	306	__uml_setup("uml_dir=", set_uml_dir,
	307	"uml_dir=<directory>\n"
	308	" The location to place the pid and umid files.\n\n"
	309	);
	310
	311	static int __init make_umid_setup(void)
	312	{
	313	/* one function with the ordering we need ... */
	314	make_uml_dir();
	315	make_umid(printf);
3a02d6c0 PBG	316	create_pid_file();
3a02d6c0 PBG	317	return 0;
1da177e4 LT	318	}
	319	__uml_postsetup(make_umid_setup);
	320
	321	/*
	322	* Overrides for Emacs so that we follow Linus's tabbing style.
	323	* Emacs will notice this stuff at the end of the file and automatically
	324	* adjust the settings for this buffer only. This must remain at the end
	325	* of the file.
	326	* ---------------------------------------------------------------------------
	327	* Local variables:
	328	* c-file-style: "linux"
	329	* End:
	330	*/