ncplib_kernel.c

linux 内核源代码

/*
 *  ncplib_kernel.c
 *
 *  Copyright (C) 1995, 1996 by Volker Lendecke
 *  Modified for big endian by J.F. Chadima and David S. Miller
 *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
 *  Modified 1999 Wolfram Pienkoss for NLS
 *  Modified 2000 Ben Harris, University of Cambridge for NFS NS meta-info
 *
 */



#include "ncplib_kernel.h"

static inline void assert_server_locked(struct ncp_server *server)
{
	if (server->lock == 0) {
		DPRINTK("ncpfs: server not locked!\n");
	}
}

static void ncp_add_byte(struct ncp_server *server, __u8 x)
{
	assert_server_locked(server);
	*(__u8 *) (&(server->packet[server->current_size])) = x;
	server->current_size += 1;
	return;
}

static void ncp_add_word(struct ncp_server *server, __le16 x)
{
	assert_server_locked(server);
	put_unaligned(x, (__le16 *) (&(server->packet[server->current_size])));
	server->current_size += 2;
	return;
}

static void ncp_add_be16(struct ncp_server *server, __u16 x)
{
	assert_server_locked(server);
	put_unaligned(cpu_to_be16(x), (__be16 *) (&(server->packet[server->current_size])));
	server->current_size += 2;
}

static void ncp_add_dword(struct ncp_server *server, __le32 x)
{
	assert_server_locked(server);
	put_unaligned(x, (__le32 *) (&(server->packet[server->current_size])));
	server->current_size += 4;
	return;
}

static void ncp_add_be32(struct ncp_server *server, __u32 x)
{
	assert_server_locked(server);
	put_unaligned(cpu_to_be32(x), (__be32 *)(&(server->packet[server->current_size])));
	server->current_size += 4;
}

static inline void ncp_add_dword_lh(struct ncp_server *server, __u32 x) {
	ncp_add_dword(server, cpu_to_le32(x));
}

static void ncp_add_mem(struct ncp_server *server, const void *source, int size)
{
	assert_server_locked(server);
	memcpy(&(server->packet[server->current_size]), source, size);
	server->current_size += size;
	return;
}

static void ncp_add_pstring(struct ncp_server *server, const char *s)
{
	int len = strlen(s);
	assert_server_locked(server);
	if (len > 255) {
		DPRINTK("ncpfs: string too long: %s\n", s);
		len = 255;
	}
	ncp_add_byte(server, len);
	ncp_add_mem(server, s, len);
	return;
}

static inline void ncp_init_request(struct ncp_server *server)
{
	ncp_lock_server(server);

	server->current_size = sizeof(struct ncp_request_header);
	server->has_subfunction = 0;
}

static inline void ncp_init_request_s(struct ncp_server *server, int subfunction)
{
	ncp_lock_server(server);
	
	server->current_size = sizeof(struct ncp_request_header) + 2;
	ncp_add_byte(server, subfunction);

	server->has_subfunction = 1;
}

static inline char *
 ncp_reply_data(struct ncp_server *server, int offset)
{
	return &(server->packet[sizeof(struct ncp_reply_header) + offset]);
}

static inline __u8 BVAL(void* data)
{
	return get_unaligned((__u8*)data);
}

static __u8
 ncp_reply_byte(struct ncp_server *server, int offset)
{
	return get_unaligned((__u8 *) ncp_reply_data(server, offset));
}

static inline __u16 WVAL_LH(void* data)
{
	return le16_to_cpu(get_unaligned((__le16*)data));
}

static __u16
 ncp_reply_le16(struct ncp_server *server, int offset)
{
	return le16_to_cpu(get_unaligned((__le16 *) ncp_reply_data(server, offset)));
}

static __u16
 ncp_reply_be16(struct ncp_server *server, int offset)
{
	return be16_to_cpu(get_unaligned((__be16 *) ncp_reply_data(server, offset)));
}

static inline __u32 DVAL_LH(void* data)
{
	return le32_to_cpu(get_unaligned((__le32*)data));
}

static __le32
 ncp_reply_dword(struct ncp_server *server, int offset)
{
	return get_unaligned((__le32 *) ncp_reply_data(server, offset));
}

static inline __u32 ncp_reply_dword_lh(struct ncp_server* server, int offset) {
	return le32_to_cpu(ncp_reply_dword(server, offset));
}

int
ncp_negotiate_buffersize(struct ncp_server *server, int size, int *target)
{
	int result;

	ncp_init_request(server);
	ncp_add_be16(server, size);

	if ((result = ncp_request(server, 33)) != 0) {
		ncp_unlock_server(server);
		return result;
	}
	*target = min_t(unsigned int, ncp_reply_be16(server, 0), size);

	ncp_unlock_server(server);
	return 0;
}


/* options: 
 *	bit 0	ipx checksum
 *	bit 1	packet signing
 */
int
ncp_negotiate_size_and_options(struct ncp_server *server, 
	int size, int options, int *ret_size, int *ret_options) {
	int result;

	/* there is minimum */
	if (size < NCP_BLOCK_SIZE) size = NCP_BLOCK_SIZE;

	ncp_init_request(server);
	ncp_add_be16(server, size);
	ncp_add_byte(server, options);
	
	if ((result = ncp_request(server, 0x61)) != 0)
	{
		ncp_unlock_server(server);
		return result;
	}

	/* NCP over UDP returns 0 (!!!) */
	result = ncp_reply_be16(server, 0);
	if (result >= NCP_BLOCK_SIZE)
		size = min(result, size);
	*ret_size = size;
	*ret_options = ncp_reply_byte(server, 4);

	ncp_unlock_server(server);
	return 0;
}

int ncp_get_volume_info_with_number(struct ncp_server* server,
			     int n, struct ncp_volume_info* target) {
	int result;
	int len;

	ncp_init_request_s(server, 44);
	ncp_add_byte(server, n);

	if ((result = ncp_request(server, 22)) != 0) {
		goto out;
	}
	target->total_blocks = ncp_reply_dword_lh(server, 0);
	target->free_blocks = ncp_reply_dword_lh(server, 4);
	target->purgeable_blocks = ncp_reply_dword_lh(server, 8);
	target->not_yet_purgeable_blocks = ncp_reply_dword_lh(server, 12);
	target->total_dir_entries = ncp_reply_dword_lh(server, 16);
	target->available_dir_entries = ncp_reply_dword_lh(server, 20);
	target->sectors_per_block = ncp_reply_byte(server, 28);

	memset(&(target->volume_name), 0, sizeof(target->volume_name));

	result = -EIO;
	len = ncp_reply_byte(server, 29);
	if (len > NCP_VOLNAME_LEN) {
		DPRINTK("ncpfs: volume name too long: %d\n", len);
		goto out;
	}
	memcpy(&(target->volume_name), ncp_reply_data(server, 30), len);
	result = 0;
out:
	ncp_unlock_server(server);
	return result;
}

int ncp_get_directory_info(struct ncp_server* server, __u8 n, 
			   struct ncp_volume_info* target) {
	int result;
	int len;

	ncp_init_request_s(server, 45);
	ncp_add_byte(server, n);

	if ((result = ncp_request(server, 22)) != 0) {
		goto out;
	}
	target->total_blocks = ncp_reply_dword_lh(server, 0);
	target->free_blocks = ncp_reply_dword_lh(server, 4);
	target->purgeable_blocks = 0;
	target->not_yet_purgeable_blocks = 0;
	target->total_dir_entries = ncp_reply_dword_lh(server, 8);
	target->available_dir_entries = ncp_reply_dword_lh(server, 12);
	target->sectors_per_block = ncp_reply_byte(server, 20);

	memset(&(target->volume_name), 0, sizeof(target->volume_name));

	result = -EIO;
	len = ncp_reply_byte(server, 21);
	if (len > NCP_VOLNAME_LEN) {
		DPRINTK("ncpfs: volume name too long: %d\n", len);
		goto out;
	}
	memcpy(&(target->volume_name), ncp_reply_data(server, 22), len);
	result = 0;
out:
	ncp_unlock_server(server);
	return result;
}

int
ncp_close_file(struct ncp_server *server, const char *file_id)
{
	int result;

	ncp_init_request(server);
	ncp_add_byte(server, 0);
	ncp_add_mem(server, file_id, 6);

	result = ncp_request(server, 66);
	ncp_unlock_server(server);
	return result;
}

int
ncp_make_closed(struct inode *inode)
{
	int err;

	err = 0;
	mutex_lock(&NCP_FINFO(inode)->open_mutex);
	if (atomic_read(&NCP_FINFO(inode)->opened) == 1) {
		atomic_set(&NCP_FINFO(inode)->opened, 0);
		err = ncp_close_file(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle);

		if (!err)
			PPRINTK("ncp_make_closed: volnum=%d, dirent=%u, error=%d\n",
				NCP_FINFO(inode)->volNumber,
				NCP_FINFO(inode)->dirEntNum, err);
	}
	mutex_unlock(&NCP_FINFO(inode)->open_mutex);
	return err;
}

static void ncp_add_handle_path(struct ncp_server *server, __u8 vol_num,
				__le32 dir_base, int have_dir_base, 
				const char *path)
{
	ncp_add_byte(server, vol_num);
	ncp_add_dword(server, dir_base);
	if (have_dir_base != 0) {
		ncp_add_byte(server, 1);	/* dir_base */
	} else {
		ncp_add_byte(server, 0xff);	/* no handle */
	}
	if (path != NULL) {
		ncp_add_byte(server, 1);	/* 1 component */
		ncp_add_pstring(server, path);
	} else {
		ncp_add_byte(server, 0);
	}
}

int ncp_dirhandle_alloc(struct ncp_server* server, __u8 volnum, __le32 dirent,
			__u8* dirhandle) {
	int result;

	ncp_init_request(server);
	ncp_add_byte(server, 12);		/* subfunction */
	ncp_add_byte(server, NW_NS_DOS);
	ncp_add_byte(server, 0);
	ncp_add_word(server, 0);
	ncp_add_handle_path(server, volnum, dirent, 1, NULL);
	if ((result = ncp_request(server, 87)) == 0) {
		*dirhandle = ncp_reply_byte(server, 0);
	}
	ncp_unlock_server(server);
	return result;
}

int ncp_dirhandle_free(struct ncp_server* server, __u8 dirhandle) {
	int result;
	
	ncp_init_request_s(server, 20);
	ncp_add_byte(server, dirhandle);
	result = ncp_request(server, 22);
	ncp_unlock_server(server);
	return result;
}

void ncp_extract_file_info(void *structure, struct nw_info_struct *target)
{
	__u8 *name_len;
	const int info_struct_size = offsetof(struct nw_info_struct, nameLen);

	memcpy(target, structure, info_struct_size);
	name_len = structure + info_struct_size;
	target->nameLen = *name_len;
	memcpy(target->entryName, name_len + 1, *name_len);
	target->entryName[*name_len] = '\0';
	target->volNumber = le32_to_cpu(target->volNumber);
	return;
}

#ifdef CONFIG_NCPFS_NFS_NS
static inline void ncp_extract_nfs_info(unsigned char *structure,
				 struct nw_nfs_info *target)
{
	target->mode = DVAL_LH(structure);
	target->rdev = DVAL_LH(structure + 8);
}
#endif

int ncp_obtain_nfs_info(struct ncp_server *server,
		        struct nw_info_struct *target)

{
	int result = 0;
#ifdef CONFIG_NCPFS_NFS_NS
	__u32 volnum = target->volNumber;

	if (ncp_is_nfs_extras(server, volnum)) {
		ncp_init_request(server);
		ncp_add_byte(server, 19);	/* subfunction */
		ncp_add_byte(server, server->name_space[volnum]);
		ncp_add_byte(server, NW_NS_NFS);
		ncp_add_byte(server, 0);
		ncp_add_byte(server, volnum);
		ncp_add_dword(server, target->dirEntNum);
		/* We must retrieve both nlinks and rdev, otherwise some server versions
		   report zeroes instead of valid data */
		ncp_add_dword_lh(server, NSIBM_NFS_MODE | NSIBM_NFS_NLINKS | NSIBM_NFS_RDEV);

		if ((result = ncp_request(server, 87)) == 0) {
			ncp_extract_nfs_info(ncp_reply_data(server, 0), &target->nfs);
			DPRINTK(KERN_DEBUG
				"ncp_obtain_nfs_info: (%s) mode=0%o, rdev=0x%x\n",
				target->entryName, target->nfs.mode,
				target->nfs.rdev);
		} else {
			target->nfs.mode = 0;
			target->nfs.rdev = 0;
		}
	        ncp_unlock_server(server);

	} else
#endif
	{
		target->nfs.mode = 0;
		target->nfs.rdev = 0;
	}
	return result;
}

/*
 * Returns information for a (one-component) name relative to
 * the specified directory.
 */
int ncp_obtain_info(struct ncp_server *server, struct inode *dir, char *path,
			struct nw_info_struct *target)
{
	__u8  volnum = NCP_FINFO(dir)->volNumber;
	__le32 dirent = NCP_FINFO(dir)->dirEntNum;
	int result;

	if (target == NULL) {
		printk(KERN_ERR "ncp_obtain_info: invalid call\n");
		return -EINVAL;
	}
	ncp_init_request(server);
	ncp_add_byte(server, 6);	/* subfunction */
	ncp_add_byte(server, server->name_space[volnum]);
	ncp_add_byte(server, server->name_space[volnum]); /* N.B. twice ?? */
	ncp_add_word(server, cpu_to_le16(0x8006));	/* get all */
	ncp_add_dword(server, RIM_ALL);
	ncp_add_handle_path(server, volnum, dirent, 1, path);