ncpfs/dir.c

 /*
 *  dir.c
 *
 *  Copyright (C) 1995 by Volker Lendecke
 *
 */

#include <linux/config.h>
#ifdef MODULE
#include <linux/module.h>
#include <linux/version.h>
#endif

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/mm.h>
#include <linux/ncp_fs.h>
#include <asm/segment.h>
#include <linux/errno.h>
#include "ncplib.h"

#define NAME_OFFSET(de) ((int) ((de)->d_name - (char *) (de)))
#define ROUND_UP(x) (((x)+3) & ~3)

static int 
ncp_dir_read(struct inode *inode, struct file *filp, char *buf, int count);

static int 
ncp_readdir(struct inode *inode, struct file *filp,
            void *dirent, filldir_t filldir);
static int
ncp_read_volume_list(struct ncp_server *server, int start_with,
		     int cache_size);

static int
ncp_do_readdir(struct ncp_server *server, struct inode *dir, int fpos,
	       int cache_size, struct ncp_dirent *entry);

static int 
get_pname(struct inode *dir, const char *name, int len,
          char **res_path, int *res_len);

static int
get_pname_static(struct inode *dir, const char *name, int len,
                 char *path, int *res_len);

static struct inode *
ncp_iget(struct inode *dir, char *path, struct ncp_dirent *finfo);

static void 
put_pname(char *path);

static struct ncp_inode_info *
ncp_find_inode(struct ncp_server *server, const char *path);

static int
ncp_lookup(struct inode *dir, const char *__name,
           int len, struct inode **result);

static int
date_dos2unix(unsigned short time,unsigned short date);

/*
static void
date_unix2dos(int unix_date,unsigned short *time, unsigned short *date);
*/

static inline void
str_upper(char *name)
{
	while (*name) {
		if (*name >= 'a' && *name <= 'z')
			*name -= ('a' - 'A');
		name++;
	}
}

static inline void
str_lower(char *name)
{
	while (*name) {
		if (*name >= 'A' && *name <= 'Z')
			*name += ('a' - 'A');
		name ++;
	}
}

static struct file_operations ncp_dir_operations = {
        NULL,			/* lseek - default */
	ncp_dir_read,		/* read - bad */
	NULL,			/* write - bad */
	ncp_readdir,		/* readdir */
	NULL,			/* select - default */
	ncp_ioctl,		/* ioctl - default */
	NULL,                   /* mmap */
	NULL,			/* no special open code */
	NULL,			/* no special release code */
	NULL			/* fsync */
};

struct inode_operations ncp_dir_inode_operations = {
	&ncp_dir_operations,	/* default directory file ops */
	NULL,			/* create */
	ncp_lookup,    		/* lookup */
	NULL,			/* link */
	NULL,    		/* unlink */
	NULL,			/* symlink */
	NULL,     		/* mkdir */
	NULL,     		/* rmdir */
	NULL,			/* mknod */
	NULL,    		/* rename */
	NULL,			/* readlink */
	NULL,			/* follow_link */
	NULL,			/* bmap */
	NULL,			/* truncate */
	NULL,			/* permission */
	NULL                    /* smap */
};


static int 
ncp_dir_read(struct inode *inode, struct file *filp, char *buf, int count)
{
	return -EISDIR;
}

/* In ncpfs, we have unique inodes across all mounted filesystems, for
   all inodes that are in memory. That's why it's enough to index the
   directory cache by the inode number. */

static unsigned long      c_ino = 0;
static int                c_size;
static int                c_seen_eof;
static int                c_last_returned_index;
static struct ncp_dirent* c_entry = NULL;

static int
ncp_readdir(struct inode *inode, struct file *filp,
            void *dirent, filldir_t filldir)
{
	int result, i = 0;
        int index = 0;
	struct ncp_dirent *entry = NULL;
        struct ncp_server *server = NCP_SERVER(inode);

	DDPRINTK("ncp_readdir: filp->f_pos = %d\n", (int)filp->f_pos);
	DDPRINTK("ncp_readdir: inode->i_ino = %ld, c_ino = %ld\n",
		 inode->i_ino, c_ino);

	if (!inode || !S_ISDIR(inode->i_mode)) {
		printk("ncp_readdir: inode is NULL or not a directory\n");
		return -EBADF;
	}

	if (c_entry == NULL) 
	{
		i = sizeof (struct ncp_dirent) * NCP_READDIR_CACHE_SIZE;
		c_entry = (struct ncp_dirent *) ncp_kmalloc(i, GFP_KERNEL);
		if (c_entry == NULL) {
			printk("ncp_readdir: no MEMORY for cache\n");
			return -ENOMEM;
		}
		for (i = 0; i < NCP_READDIR_CACHE_SIZE; i++) {
			c_entry[i].path =
                                (char *) ncp_kmalloc(NCP_MAXNAMELEN + 1,
                                                     GFP_KERNEL);
                        if (c_entry[i].path == NULL) {
                                DPRINTK("ncp_readdir: could not alloc path\n");
				while (--i>=0)
					kfree(c_entry[i].path);
				kfree(c_entry);
				c_entry = NULL;
				return -ENOMEM;
                        }
                }
	}

        if (filp->f_pos == 0) {
                ncp_invalid_dir_cache(inode->i_ino);
        }

	if (inode->i_ino == c_ino) {
		for (i = 0; i < c_size; i++) {
			if (filp->f_pos == c_entry[i].f_pos) {
                                entry = &c_entry[i];
                                c_last_returned_index = i;
                                index = i;
                                break;
			}
		}
                if ((entry == NULL) && c_seen_eof)
                        return 0;
	}

	if (entry == NULL) {
		DPRINTK("ncp_readdir: Not found in cache.\n");

		if (inode->i_ino == (int)&(server->root)) {

			result = ncp_read_volume_list(server, filp->f_pos,
						      NCP_READDIR_CACHE_SIZE);
			DPRINTK("ncp_read_volume_list returned %d\n", result);

		} else {

			result = ncp_do_readdir(server, inode, filp->f_pos,
						NCP_READDIR_CACHE_SIZE,
						c_entry);
			DPRINTK("ncp_readdir returned %d\n", result);
		}
			
		
		if (result < 0) {
			c_ino = 0;
			return result;
		}

		if (result > 0) {
                        c_seen_eof = (result < NCP_READDIR_CACHE_SIZE);
			c_ino  = inode->i_ino;
			c_size = result;
			entry = c_entry;
                        c_last_returned_index = 0;
                        index = 0;

			for (i = 0; i < c_size; i++) {
				str_lower(c_entry[i].path);
			}
		}
	}

        if (entry == NULL) {
                /* Nothing found, even from a ncp call */
                return 0;
        }

        while (index < c_size) {

                /* We found it.  For getwd(), we have to return the
                   correct inode in d_ino if the inode is currently in
                   use. Otherwise the inode number does not
                   matter. (You can argue a lot about this..) */ 

                int path_len;
                int len;
                struct ncp_inode_info *ino_info;
                char complete_path[NCP_MAXPATHLEN];

		len = strlen(entry->path);
                if ((result = get_pname_static(inode, entry->path, len,
                                               complete_path,
                                               &path_len)) < 0)
                        return result;

                ino_info = ncp_find_inode(server, complete_path);

                /* Some programs seem to be confused about a zero
                   inode number, so we set it to one.  Thanks to
                   Gordon Chaffee for this one. */
                if (ino_info == NULL) {
                        ino_info = (struct ncp_inode_info *) 1;
                }

		DDPRINTK("ncp_readdir: entry->path = %s\n", entry->path);
		DDPRINTK("ncp_readdir: entry->f_pos = %ld\n", entry->f_pos);

                if (filldir(dirent, entry->path, len,
                            entry->f_pos, (ino_t)ino_info) < 0) {
                        break;
                }

                if (   (inode->i_ino != c_ino)
                    || (entry->f_pos != filp->f_pos)) {
                        /* Someone has destroyed the cache while we slept
                           in filldir */
                        break;
                }
                filp->f_pos += 1;
                index += 1;
                entry += 1;
	}
	return 0;
}

static int
ncp_read_volume_list(struct ncp_server *server, int start_with, int cache_size)
{
	struct ncp_dirent *entry = c_entry;

	int total_count = 0;
	int i;

	for (i=0; i<NCP_NUMBER_OF_VOLUMES; i++) {

		struct ncp_volume_info info;

		if (ncp_get_volume_info_with_number(server, i, &info) != 0) {
			return total_count;
		}

		if (strlen(info.volume_name) > 0) {

			if (total_count < start_with) {
				DPRINTK("ncp_read_volumes: skipped vol: %s\n",
					info.volume_name);
			} else if (total_count >= start_with + cache_size) {
				return (total_count - start_with);
			} else {
				DPRINTK("ncp_read_volumes: found vol %s\n",
					info.volume_name);
				entry->attr   = aDIR;
				entry->mtime  = 0;
				entry->ctime  = 0;
				entry->atime  = 0;
				entry->size   = 1024;
				entry->f_pos  = total_count;
				strcpy(entry->path, info.volume_name);
				entry += 1;
			}

			total_count += 1;
		}
	}
	return (total_count - start_with);
}

static int
ncp_do_readdir(struct ncp_server *server, struct inode *dir, int fpos,
	       int cache_size, struct ncp_dirent *entry)
{
	struct ncp_filesearch_info fsinfo;
	struct ncp_file_info       finfo;

	int total_count = 0;

	void doit(int attr) {
		
		if (ncp_file_search_init(server, 0, NCP_FINFO(dir)->path,
					 &fsinfo) != 0) {
			DPRINTK("could not fs init\n");
			return;
		}
		
		while (ncp_file_search_continue(server, &fsinfo, attr, "*",
						&finfo) == 0) {
			
			if (total_count < fpos) {
				DPRINTK("ncp_do_readdir: skipped file: %s\n",
					finfo.file_name);
			} else if (total_count >= fpos + cache_size) {
				return;
			} else {
				DPRINTK("ncp_do_readdir: found file: %s\n",
					finfo.file_name);
				
				entry->attr  = attr;
				entry->mtime =
					date_dos2unix(finfo.update_time,
						      finfo.update_date);
				entry->ctime =
					date_dos2unix(0, finfo.creation_date);
				entry->atime =
					date_dos2unix(0, finfo.access_date);
;
				entry->size  = (attr & aDIR) != 0 ?
					1024 : finfo.file_length;
				entry->f_pos = total_count;
				strcpy(entry->path, finfo.file_name);
				entry += 1;
			}
			total_count += 1;
		}
		return;
	}

	doit(0);
	doit(aDIR);

	return (total_count - fpos);
}

void
ncp_init_dir_cache(void)
{
        c_ino   = 0;
        c_entry = NULL;
}

void
ncp_invalid_dir_cache(unsigned long ino)
{
	if (ino == c_ino) {
                c_ino = 0;
                c_seen_eof = 0;
        }
}

void
ncp_free_dir_cache(void)
{
        int i;

        DPRINTK("ncp_free_dir_cache: enter\n");
        
        if (c_entry == NULL)
                return;

        for (i = 0; i < NCP_READDIR_CACHE_SIZE; i++) {
                ncp_kfree_s(c_entry[i].path, NAME_MAX + 1);
        }

        ncp_kfree_s(c_entry,
                    sizeof(struct ncp_dirent) * NCP_READDIR_CACHE_SIZE);
        c_entry = NULL;

        DPRINTK("ncp_free_dir_cache: exit\n");
}


/* get_pname_static: it expects the res_path to be a preallocated
   string of len NCP_MAXPATHLEN. */
static int
get_pname_static(struct inode *dir, const char *name, int len,
                 char *path, int *res_len)
{
        char *parentname = NCP_INOP(dir)->finfo.path;
        int   parentlen  = NCP_INOP(dir)->finfo.len;

#if 1
        if (parentlen != strlen(parentname)) {
                printk("get_pname: parent->finfo.len = %d instead of %d\n",
                       parentlen, strlen(parentname));
                parentlen = strlen(parentname);
        }
	
#endif
	DPRINTK("get_pname_static: parentname = %s, len = %d\n",
                 parentname, parentlen);
	
        if (len > NCP_MAXNAMELEN) {
                return -ENAMETOOLONG;
        }

	/* Fast cheat for . */
	if (len == 0 || (len == 1 && name[0] == '.')) {

		memcpy(path, parentname, parentlen + 1);
		*res_len = parentlen;
		return 0;
	}
	
	/* Hmm, what about .. ? */
	if (len == 2 && name[0] == '.' && name[1] == '.') {

		char *pos = strrchr(parentname, '\\');

                if (   (pos == NULL)
                    && (parentlen == 0)) {

                        /* We're at the top */

                        path[0] = '\\';
                        path[1] = '\0';
                        *res_len  = 2;
                        return 0;
                }
                        
                
		if (pos == NULL) {
			printk("ncp_make_name: Bad parent NCP-name: %s",
                               parentname);
			return -ENODATA;
		}
		
		len = pos - parentname;

	        memcpy(path, parentname, len);
		path[len] = '\0';
	}
	else if (parentlen == 0) {

		memcpy(path, name, len);
		path[len]   = ':';
		path[len+1] = '\0';
		len = len+1;
	}
	else
	{
		if (len + parentlen + 2 > NCP_MAXPATHLEN) 
			return -ENAMETOOLONG;
				
		memcpy(path, parentname, parentlen);
		path[parentlen] = '\\';
		memcpy(path + parentlen + 1, name, len);
		path[parentlen + 1 + len] = '\0';
		len = parentlen + len + 1;
	}

	*res_len = len;

	DPRINTK("get_pname: path = %s, *pathlen = %d\n",
                 path, *res_len);
	return 0;
}
        
static int 
get_pname(struct inode *dir, const char *name, int len,
          char **res_path, int *res_len)
{
        char result[NCP_MAXPATHLEN];
        int  result_len;
        int  res;

        if ((res = get_pname_static(dir,name,len,result,&result_len) != 0)) {
                return res;
        }

        if ((*res_path = ncp_kmalloc(result_len+1, GFP_KERNEL)) == NULL) {
                printk("get_pname: Out of memory while allocating name.");
                return -ENOMEM;
        }

        strcpy(*res_path, result);
        *res_len = result_len;
        return 0;
}

static void
put_pname(char *path)
{
	ncp_kfree_s(path, 0);
}

/* Insert a NEW ncp_inode_info into the inode tree of our filesystem,
   under dir. The caller must assure that it's not already there. We
   assume that path is allocated for us. */

static struct inode *
ncp_iget(struct inode *dir, char *path, struct ncp_dirent *finfo)
{
	struct inode *inode;
        struct ncp_inode_info *new_inode_info;
        struct ncp_inode_info *root;

	if (!dir) {
		printk("ncp_iget: dir is NULL\n");
		return NULL;
	}

        if (!path) {
                printk("ncp_iget: path is NULL\n");
                return NULL;
        }

	if (!finfo) {
		printk("ncp_iget: finfo is NULL\n");
		return NULL;
	}

        new_inode_info = ncp_kmalloc(sizeof(struct ncp_inode_info),
                                     GFP_KERNEL);

        if (new_inode_info == NULL) {
                printk("ncp_iget: could not alloc mem for %s\n", path);
                return NULL;
        }

        new_inode_info->state = INODE_LOOKED_UP;
        new_inode_info->nused = 0;
        new_inode_info->dir   = NCP_INOP(dir);

        new_inode_info->finfo        = *finfo;
        new_inode_info->finfo.opened = 0;
        new_inode_info->finfo.path   = path;
        new_inode_info->finfo.len    = strlen(path);

        NCP_INOP(dir)->nused += 1;

        /* We have to link the new inode_info into the doubly linked
           list of inode_infos to make a complete linear search
           possible. */

        root = &(NCP_SERVER(dir)->root);

        new_inode_info->prev = root;
        new_inode_info->next = root->next;
        root->next->prev = new_inode_info;
        root->next = new_inode_info;
        
	if (!(inode = iget(dir->i_sb, (int)new_inode_info))) {
		printk("ncp_iget: iget failed!");
		return NULL;
	}

	return inode;
}

void
ncp_free_inode_info(struct ncp_inode_info *i)
{
        if (i == NULL) {
                printk("ncp_free_inode: i == NULL\n");
                return;
        }

        i->state = INODE_CACHED;
        while ((i->nused == 0) && (i->state == INODE_CACHED)) {
                struct ncp_inode_info *dir = i->dir;

                i->next->prev = i->prev;
                i->prev->next = i->next;

                ncp_kfree_s(i->finfo.path, i->finfo.len+1);
                ncp_kfree_s(i, sizeof(struct ncp_inode_info));

                if (dir == NULL) return;

                (dir->nused)--;
                i = dir;
        }
}
        
void
ncp_init_root(struct ncp_server *server)
{
        struct ncp_inode_info *root = &(server->root);

	DPRINTK("ncp_init_root: server %s\n", server->m.server_name);

        root->finfo.opened = 0;
	root->finfo.attr   = aDIR;
	root->finfo.size   = 1024;
	root->finfo.mtime  = 0;
	root->finfo.ctime  = 0;
	root->finfo.atime  = 0;

	server->root_path  = '\0';
	root->finfo.path   = &(server->root_path);
	root->finfo.len    = 0;

        root->state = INODE_LOOKED_UP;
        root->nused = 1;
        root->dir   = NULL;
        root->next = root->prev = root;
        return;
}

void
ncp_free_all_inodes(struct ncp_server *server)
{
        /* Here nothing should be to do. I do not know whether it's
           better to leave some memory allocated or be stuck in an
           endless loop */
#if 1
        struct ncp_inode_info *root = &(server->root);

        if (root->next != root) {
                printk("ncp_free_all_inodes: INODES LEFT!!!\n");
        }

        while (root->next != root) {
                printk("ncp_free_all_inodes: freeing inode\n");
                ncp_free_inode_info(root->next);
                /* In case we have an endless loop.. */
                schedule();
        }
#endif        
        
        return;
}

/* We will search the inode that belongs to this name, currently by a
   complete linear search through the inodes belonging to this
   filesystem. This has to be fixed. */

static struct ncp_inode_info *
ncp_find_inode(struct ncp_server *server, const char *path)
{
        struct ncp_inode_info *result = &(server->root);

        if (path == NULL)
                return NULL;

        do {
                if (strcmp(result->finfo.path, path) == 0)
                        return result;
                result = result->next;

        } while (result != &(server->root));

        return NULL;
}

static int 
ncp_lookup(struct inode *dir, const char *__name, int len,
           struct inode **result)
{
	char *name = NULL;
	struct ncp_dirent finfo;
	struct ncp_server *server;
        struct ncp_inode_info *result_info;
	int error;
        int found_in_cache;
	int path_len;

	*result = NULL;

	if (!dir || !S_ISDIR(dir->i_mode)) {
		printk("ncp_lookup: inode is NULL or not a directory.\n");
		iput(dir);
		return -ENOENT;
	}

        DPRINTK("ncp_lookup: %s\n", __name);

	server = NCP_SERVER(dir);

	/* Fast cheat for . */
	if (len == 0 || (len == 1 && __name[0] == '.')) {
		*result = dir;
		return 0;
	}

	/* Now we will have to build up an NCP filename. */
	if ((error = get_pname(dir, __name, len, &name, &path_len)) < 0) {
		iput(dir);
		return error;
	}

        result_info = ncp_find_inode(NCP_SERVER(dir), name);

        if (result_info != 0) {

                if (result_info->state == INODE_CACHED)
                        result_info->state = INODE_LOOKED_UP;

                put_pname(name);

                /* Here we convert the inode_info address into an
                   inode number */

                *result = iget(dir->i_sb, (int)result_info);
                iput(dir);

                if (*result == NULL) {
                        return -EACCES;
                }

		return 0;
        }

	/* Ok, now we have made our name. We have to build a new
           ncp_inode_info struct and insert it into the tree, if it is
           a name that exists on the server */

        /* If the file is in the dir cache, we do not have to ask the
           server. */

        found_in_cache = 0;
        
        if (dir->i_ino == c_ino) {
                int first = c_last_returned_index;
                int i;

                i = first;
                do {
                        DDPRINTK("ncp_lookup: trying index: %d, name: %s\n",
                                i, c_entry[i].path);
                        if (strcmp(c_entry[i].path, __name) == 0) {
                                DPRINTK("ncp_lookup: found in cache!\n");
                                finfo = c_entry[i];
                                finfo.path = NULL; /* It's not ours! */
                                found_in_cache = 1;
                                break;
                        }
                        i = (i + 1) % c_size;
                        DDPRINTK("ncp_lookup: index %d, name %s failed\n",
                                 i, c_entry[i].path);
                } while (i != first);
        }

        if (found_in_cache == 0) {

		char this_name[len+1];

		memcpy(this_name, __name, len);
		this_name[len] = 0;

		if (dir->i_ino == (int)&(server->root)) {

			/* We want to look up a volume. We only want
                           to know whether it exists, nothing more. */
			int vol_no;

			DPRINTK("ncp_lookup: looking up volume %s\n",
				this_name);

			if (ncp_get_volume_number(server,this_name,
						  &vol_no)!=0) {
				put_pname(name);
				iput(dir);
				return -ENOENT;
			}

			finfo.attr    = aDIR;
			finfo.mtime   = 0;
			finfo.ctime   = 0;
			finfo.atime   = 0;
			finfo.size    = 1024;

		} else {
			struct ncp_file_info ninfo;
			if (ncp_get_finfo(server, 0, NCP_FINFO(dir)->path,
					  this_name, &ninfo) != 0) {
				error = -ENOENT;
			}

			finfo.attr   = ninfo.file_attributes;
			finfo.mtime  = date_dos2unix(ninfo.update_time,
						     ninfo.update_date);
			finfo.ctime  = date_dos2unix(0, ninfo.creation_date);
			finfo.atime  = date_dos2unix(0, ninfo.access_date);
			finfo.size   = (ninfo.file_attributes & aDIR) != 0
				? 1024 : ninfo.file_length;
		}

                if (error < 0) {
                        put_pname(name);
                        iput(dir);
                        return error;
                }
        }

	if (!(*result = ncp_iget(dir, name, &finfo))) {
		put_pname(name);
		iput(dir);
		return -EACCES;
	}

        DDPRINTK("ncp_lookup: %s => %lu\n", name, (unsigned long)result_info);
	iput(dir);
	return 0;
}




/* The following are taken directly from msdos-fs */

/* Linear day numbers of the respective 1sts in non-leap years. */

static int day_n[] = { 0,31,59,90,120,151,181,212,243,273,304,334,0,0,0,0 };
		  /* JanFebMarApr May Jun Jul Aug Sep Oct Nov Dec */


extern struct timezone sys_tz;

/*
static int
utc2local(int time)
{
        return time - sys_tz.tz_minuteswest*60;
}
*/

static int
local2utc(int time)
{
        return time + sys_tz.tz_minuteswest*60;
}

/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */

static int
date_dos2unix(unsigned short time,unsigned short date)
{
	int month,year,secs;

	month = ((date >> 5) & 15)-1;
	year = date >> 9;
	secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400*
	    ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
	    month < 2 ? 1 : 0)+3653);
			/* days since 1.1.70 plus 80's leap day */
	return local2utc(secs);
}


/* Convert linear UNIX date to a MS-DOS time/date pair. */
#if 0
static void
date_unix2dos(int unix_date,unsigned short *time, unsigned short *date)
{
	int day,year,nl_day,month;

	unix_date = utc2local(unix_date);
	*time = (unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
	    (((unix_date/3600) % 24) << 11);
	day = unix_date/86400-3652;
	year = day/365;
	if ((year+3)/4+365*year > day) year--;
	day -= (year+3)/4+365*year;
	if (day == 59 && !(year & 3)) {
		nl_day = day;
		month = 2;
	}
	else {
		nl_day = (year & 3) || day <= 59 ? day : day-1;
		for (month = 0; month < 12; month++)
			if (day_n[month] > nl_day) break;
	}
	*date = nl_day-day_n[month-1]+1+(month << 5)+(year << 9);
}
#endif