// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2020, Microsoft Corporation.
 *
 *   Author(s): Steve French <stfrench@microsoft.com>
 *              Suresh Jayaraman <sjayaraman@suse.de>
 *              Jeff Layton <jlayton@kernel.org>
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/inet.h>
#include <linux/ctype.h>
#include "cifsglob.h"
#include "cifsproto.h"

/* extract the host portion of the UNC string */
char *extract_hostname(const char *unc)
{
        const char *src;
        char *dst, *delim;
        unsigned int len;

        /* skip double chars at beginning of string */
        /* BB: check validity of these bytes? */
        if (strlen(unc) < 3)
                return ERR_PTR(-EINVAL);
        for (src = unc; *src && *src == '\\'; src++)
                ;
        if (!*src)
                return ERR_PTR(-EINVAL);

        /* delimiter between hostname and sharename is always '\\' now */
        delim = strchr(src, '\\');
        if (!delim)
                return ERR_PTR(-EINVAL);

        len = delim - src;
        dst = kmalloc((len + 1), GFP_KERNEL);
        if (dst == NULL)
                return ERR_PTR(-ENOMEM);

        memcpy(dst, src, len);
        dst[len] = '\0';

        return dst;
}

char *extract_sharename(const char *unc)
{
        const char *src;
        char *delim, *dst;

        /* skip double chars at the beginning */
        src = unc + 2;

        /* share name is always preceded by '\\' now */
        delim = strchr(src, '\\');
        if (!delim)
                return ERR_PTR(-EINVAL);
        delim++;

        /* caller has to free the memory */
        dst = kstrdup(delim, GFP_KERNEL);
        if (!dst)
                return ERR_PTR(-ENOMEM);

        return dst;
}