fs/smb/server/misc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
   4  *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/xattr.h>
   9 #include <linux/fs.h>
  10 #include <linux/unicode.h>
  11
  12 #include "misc.h"
  13 #include "smb_common.h"
  14 #include "connection.h"
  15 #include "vfs.h"
  16
  17 #include "mgmt/share_config.h"
  18
  19 /**
  20  * match_pattern() - compare a string with a pattern which might include
  21  * wildcard '*' and '?'
  22  * TODO : implement consideration about DOS_DOT, DOS_QM and DOS_STAR
  23  *
  24  * @str:        string to compare with a pattern
  25  * @len:        string length
  26  * @pattern:    pattern string which might include wildcard '*' and '?'
  27  *
  28  * Return:      0 if pattern matched with the string, otherwise non zero value
  29  */
  30 int match_pattern(const char *str, size_t len, const char *pattern)
  31 {
  32         const char *s = str;
  33         const char *p = pattern;
  34         bool star = false;
  35
  36         while (*s && len) {
  37                 switch (*p) {
  38                 case '?':
  39                         s++;
  40                         len--;
  41                         p++;
  42                         break;
  43                 case '*':
  44                         star = true;
  45                         str = s;
  46                         if (!*++p)
  47                                 return true;
  48                         pattern = p;
  49                         break;
  50                 default:
  51                         if (tolower(*s) == tolower(*p)) {
  52                                 s++;
  53                                 len--;
  54                                 p++;
  55                         } else {
  56                                 if (!star)
  57                                         return false;
  58                                 str++;
  59                                 s = str;
  60                                 p = pattern;
  61                         }
  62                         break;
  63                 }
  64         }
  65
  66         if (*p == '*')
  67                 ++p;
  68         return !*p;
  69 }
  70
  71 /*
  72  * is_char_allowed() - check for valid character
  73  * @ch:         input character to be checked
  74  *
  75  * Return:      1 if char is allowed, otherwise 0
  76  */
  77 static inline int is_char_allowed(char ch)
  78 {
  79         /* check for control chars, wildcards etc. */
  80         if (!(ch & 0x80) &&
  81             (ch <= 0x1f ||
  82              ch == '?' || ch == '"' || ch == '<' ||
  83              ch == '>' || ch == '|' || ch == '*'))
  84                 return 0;
  85
  86         return 1;
  87 }
  88
  89 int ksmbd_validate_filename(char *filename)
  90 {
  91         while (*filename) {
  92                 char c = *filename;
  93
  94                 filename++;
  95                 if (!is_char_allowed(c)) {
  96                         ksmbd_debug(VFS, "File name validation failed: 0x%x\n", c);
  97                         return -ENOENT;
  98                 }
  99         }
 100
 101         return 0;
 102 }
 103
 104 static int ksmbd_validate_stream_name(char *stream_name)
 105 {
 106         while (*stream_name) {
 107                 char c = *stream_name;
 108
 109                 stream_name++;
 110                 if (c == '/' || c == ':' || c == '\\') {
 111                         pr_err("Stream name validation failed: %c\n", c);
 112                         return -ENOENT;
 113                 }
 114         }
 115
 116         return 0;
 117 }
 118
 119 int parse_stream_name(char *filename, char **stream_name, int *s_type)
 120 {
 121         char *stream_type;
 122         char *s_name;
 123         int rc = 0;
 124
 125         s_name = filename;
 126         filename = strsep(&s_name, ":");
 127         ksmbd_debug(SMB, "filename : %s, streams : %s\n", filename, s_name);
 128         if (strchr(s_name, ':')) {
 129                 stream_type = s_name;
 130                 s_name = strsep(&stream_type, ":");
 131
 132                 rc = ksmbd_validate_stream_name(s_name);
 133                 if (rc < 0) {
 134                         rc = -ENOENT;
 135                         goto out;
 136                 }
 137
 138                 ksmbd_debug(SMB, "stream name : %s, stream type : %s\n", s_name,
 139                             stream_type);
 140                 if (!strncasecmp("$data", stream_type, 5))
 141                         *s_type = DATA_STREAM;
 142                 else if (!strncasecmp("$index_allocation", stream_type, 17))
 143                         *s_type = DIR_STREAM;
 144                 else
 145                         rc = -ENOENT;
 146         }
 147
 148         *stream_name = s_name;
 149 out:
 150         return rc;
 151 }
 152
 153 /**
 154  * convert_to_nt_pathname() - extract and return windows path string
 155  *      whose share directory prefix was removed from file path
 156  * @share: ksmbd_share_config pointer
 157  * @path: path to report
 158  *
 159  * Return : windows path string or error
 160  */
 161
 162 char *convert_to_nt_pathname(struct ksmbd_share_config *share,
 163                              const struct path *path)
 164 {
 165         char *pathname, *ab_pathname, *nt_pathname;
 166         int share_path_len = share->path_sz;
 167
 168         pathname = kmalloc(PATH_MAX, GFP_KERNEL);
 169         if (!pathname)
 170                 return ERR_PTR(-EACCES);
 171
 172         ab_pathname = d_path(path, pathname, PATH_MAX);
 173         if (IS_ERR(ab_pathname)) {
 174                 nt_pathname = ERR_PTR(-EACCES);
 175                 goto free_pathname;
 176         }
 177
 178         if (strncmp(ab_pathname, share->path, share_path_len)) {
 179                 nt_pathname = ERR_PTR(-EACCES);
 180                 goto free_pathname;
 181         }
 182
 183         nt_pathname = kzalloc(strlen(&ab_pathname[share_path_len]) + 2, GFP_KERNEL);
 184         if (!nt_pathname) {
 185                 nt_pathname = ERR_PTR(-ENOMEM);
 186                 goto free_pathname;
 187         }
 188         if (ab_pathname[share_path_len] == '\0')
 189                 strcpy(nt_pathname, "/");
 190         strcat(nt_pathname, &ab_pathname[share_path_len]);
 191
 192         ksmbd_conv_path_to_windows(nt_pathname);
 193
 194 free_pathname:
 195         kfree(pathname);
 196         return nt_pathname;
 197 }
 198
 199 int get_nlink(struct kstat *st)
 200 {
 201         int nlink;
 202
 203         nlink = st->nlink;
 204         if (S_ISDIR(st->mode))
 205                 nlink--;
 206
 207         return nlink;
 208 }
 209
 210 void ksmbd_conv_path_to_unix(char *path)
 211 {
 212         strreplace(path, '\\', '/');
 213 }
 214
 215 void ksmbd_strip_last_slash(char *path)
 216 {
 217         int len = strlen(path);
 218
 219         while (len && path[len - 1] == '/') {
 220                 path[len - 1] = '\0';
 221                 len--;
 222         }
 223 }
 224
 225 void ksmbd_conv_path_to_windows(char *path)
 226 {
 227         strreplace(path, '/', '\\');
 228 }
 229
 230 char *ksmbd_casefold_sharename(struct unicode_map *um, const char *name)
 231 {
 232         char *cf_name;
 233         int cf_len;
 234
 235         cf_name = kzalloc(KSMBD_REQ_MAX_SHARE_NAME, GFP_KERNEL);
 236         if (!cf_name)
 237                 return ERR_PTR(-ENOMEM);
 238
 239         if (IS_ENABLED(CONFIG_UNICODE) && um) {
 240                 const struct qstr q_name = {.name = name, .len = strlen(name)};
 241
 242                 cf_len = utf8_casefold(um, &q_name, cf_name,
 243                                        KSMBD_REQ_MAX_SHARE_NAME);
 244                 if (cf_len < 0)
 245                         goto out_ascii;
 246
 247                 return cf_name;
 248         }
 249
 250 out_ascii:
 251         cf_len = strscpy(cf_name, name, KSMBD_REQ_MAX_SHARE_NAME);
 252         if (cf_len < 0) {
 253                 kfree(cf_name);
 254                 return ERR_PTR(-E2BIG);
 255         }
 256
 257         for (; *cf_name; ++cf_name)
 258                 *cf_name = isascii(*cf_name) ? tolower(*cf_name) : *cf_name;
 259         return cf_name - cf_len;
 260 }
 261
 262 /**
 263  * ksmbd_extract_sharename() - get share name from tree connect request
 264  * @um: pointer to a unicode_map structure for character encoding handling
 265  * @treename:   buffer containing tree name and share name
 266  *
 267  * Return:      share name on success, otherwise error
 268  */
 269 char *ksmbd_extract_sharename(struct unicode_map *um, const char *treename)
 270 {
 271         const char *name = treename, *pos = strrchr(name, '\\');
 272
 273         if (pos)
 274                 name = (pos + 1);
 275
 276         /* caller has to free the memory */
 277         return ksmbd_casefold_sharename(um, name);
 278 }
 279
 280 /**
 281  * convert_to_unix_name() - convert windows name to unix format
 282  * @share:      ksmbd_share_config pointer
 283  * @name:       file name that is relative to share
 284  *
 285  * Return:      converted name on success, otherwise NULL
 286  */
 287 char *convert_to_unix_name(struct ksmbd_share_config *share, const char *name)
 288 {
 289         int no_slash = 0, name_len, path_len;
 290         char *new_name;
 291
 292         if (name[0] == '/')
 293                 name++;
 294
 295         path_len = share->path_sz;
 296         name_len = strlen(name);
 297         new_name = kmalloc(path_len + name_len + 2, GFP_KERNEL);
 298         if (!new_name)
 299                 return new_name;
 300
 301         memcpy(new_name, share->path, path_len);
 302         if (new_name[path_len - 1] != '/') {
 303                 new_name[path_len] = '/';
 304                 no_slash = 1;
 305         }
 306
 307         memcpy(new_name + path_len + no_slash, name, name_len);
 308         path_len += name_len + no_slash;
 309         new_name[path_len] = 0x00;
 310         return new_name;
 311 }
 312
 313 char *ksmbd_convert_dir_info_name(struct ksmbd_dir_info *d_info,
 314                                   const struct nls_table *local_nls,
 315                                   int *conv_len)
 316 {
 317         char *conv;
 318         int  sz = min(4 * d_info->name_len, PATH_MAX);
 319
 320         if (!sz)
 321                 return NULL;
 322
 323         conv = kmalloc(sz, GFP_KERNEL);
 324         if (!conv)
 325                 return NULL;
 326
 327         /* XXX */
 328         *conv_len = smbConvertToUTF16((__le16 *)conv, d_info->name,
 329                                       d_info->name_len, local_nls, 0);
 330         *conv_len *= 2;
 331
 332         /* We allocate buffer twice bigger than needed. */
 333         conv[*conv_len] = 0x00;
 334         conv[*conv_len + 1] = 0x00;
 335         return conv;
 336 }
 337
 338 /*
 339  * Convert the NT UTC (based 1601-01-01, in hundred nanosecond units)
 340  * into Unix UTC (based 1970-01-01, in seconds).
 341  */
 342 struct timespec64 ksmbd_NTtimeToUnix(__le64 ntutc)
 343 {
 344         struct timespec64 ts;
 345
 346         /* Subtract the NTFS time offset, then convert to 1s intervals. */
 347         s64 t = le64_to_cpu(ntutc) - NTFS_TIME_OFFSET;
 348         u64 abs_t;
 349
 350         /*
 351          * Unfortunately can not use normal 64 bit division on 32 bit arch, but
 352          * the alternative, do_div, does not work with negative numbers so have
 353          * to special case them
 354          */
 355         if (t < 0) {
 356                 abs_t = -t;
 357                 ts.tv_nsec = do_div(abs_t, 10000000) * 100;
 358                 ts.tv_nsec = -ts.tv_nsec;
 359                 ts.tv_sec = -abs_t;
 360         } else {
 361                 abs_t = t;
 362                 ts.tv_nsec = do_div(abs_t, 10000000) * 100;
 363                 ts.tv_sec = abs_t;
 364         }
 365
 366         return ts;
 367 }
 368
 369 /* Convert the Unix UTC into NT UTC. */
 370 inline u64 ksmbd_UnixTimeToNT(struct timespec64 t)
 371 {
 372         /* Convert to 100ns intervals and then add the NTFS time offset. */
 373         return (u64)t.tv_sec * 10000000 + t.tv_nsec / 100 + NTFS_TIME_OFFSET;
 374 }
 375
 376 inline long long ksmbd_systime(void)
 377 {
 378         struct timespec64       ts;
 379
 380         ktime_get_real_ts64(&ts);
 381         return ksmbd_UnixTimeToNT(ts);
 382 }