source4/ntvfs/proxy/lib/cache/cache.c

   1 /*
   2    Unix SMB/PROXY cache engine.
   3
   4    Copyright (C) 2007 Sam Liddicott <sam@liddicott.com>
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "libcli/raw/libcliraw.h"
  22 #include "libcli/smb_composite/smb_composite.h"
  23 #include "auth/auth.h"
  24 #include "auth/credentials/credentials.h"
  25 #include "ntvfs/ntvfs.h"
  26 #include "lib/util/dlinklist.h"
  27 #include "param/param.h"
  28 #include "cache.h"
  29 #include <sys/types.h>
  30 #include <unistd.h>
  31 #include <sys/stat.h>
  32 #include <fcntl.h>
  33 #include "zconf.h"
  34 #include "ntvfs/proxy/lib/compression/zlib.h"
  35
  36 /* like mkdir -p */
  37 int mkpath(const char* at, const char* pathname, mode_t mode)
  38 {
  39         char path[MAXPATHLEN];
  40         char* next;
  41         int len;
  42         struct stat stat_path;
  43
  44         strncpy(path, at, MAXPATHLEN);
  45         len=strlen(path);
  46         next=path+len;
  47         if (len==0 || (path[len-1]!='/' && len < MAXPATHLEN-1)) {
  48                 strncat(path,"/",MAXPATHLEN - len - 1);
  49                 len=strlen(path);
  50                 next=path+len;
  51         }
  52         strncat(path, pathname, MAXPATHLEN - len - 1);
  53
  54         /* get to the non / portions of pathname */
  55         while (*next=='/') next++;
  56         next=strchr(next, '/');
  57
  58         while (! next || *next) {
  59                 if (next) *next=0;
  60                 if (stat(path, &stat_path)) {
  61                         /* doesn't exist, try to create it */
  62                         if (errno!=ENOENT) return -1;
  63                         if (mkdir(path, mode)) return -1;
  64                 } else if (! S_ISDIR(stat_path.st_mode)) {
  65                         /* exists, but not a directory */
  66                         errno=ENOTDIR;
  67                         return -1;
  68                 }
  69                 /* so it's a directory (now) */
  70                 if (! next) return 0;
  71                 *next='/';
  72                 while (*next=='/') next++;
  73                 next=strchr(next+1, '/');
  74         }
  75         return 0;
  76 }
  77
  78 struct cache_context *new_cache_context(TALLOC_CTX * memctx, const char* root, const char *server, const char *share)
  79 {
  80         struct cache_context *context=talloc_zero(memctx, struct cache_context);
  81         if (! context) return NULL;
  82
  83         context->root=talloc_strdup(context, root);
  84         context->server=strlower_talloc(context, server);
  85         /* share names are never case sensitive */
  86         context->share=strlower_talloc(context, share);
  87         context->prefix=talloc_asprintf(context,"%s/%s/", context->server, context->share);
  88         DEBUG(5,("New cache context: root=%s, prefix=%s\n",
  89                          context->root, context->prefix));
  90         return context;
  91 }
  92
  93 void clear_cache_storage(struct cache_file_entry *cache)
  94 {
  95 //      if (cache->store_name && *(cache->store_name)) {
  96 //              unlink(cache->store_name);
  97 //              talloc_free(cache->store_name);
  98 //              cache->store_name=NULL;
  99 //      }
 100 }
 101
 102 /* op-lock has probably been broken. We can no-longer read-cache for this file
 103    in fact the whole cache is invalid for this file now, but we can use it as
 104    a reference for delta-compression syncs if the remote server supports it */
 105 void cache_file_stale(struct cache_file_entry *cache)
 106 {
 107         if (cache) {
 108                 cache->status &= ~ CACHE_READ;
 109                 cache->validated_extent=0;
 110                 DEBUG(CACHE_DEBUG_LEVEL,("Cache file %s no longer good to read from\n",cache->cache_name));
 111         }
 112 }
 113
 114 void cache_close(struct cache_file_entry *cache) {
 115         if (cache && cache->fd>=0) {
 116                 close(cache->fd);
 117                 cache->fd=-1;
 118         }
 119 }
 120
 121 void cache_beopen(struct cache_file_entry *cache) {
 122         if (cache->fd<=0) cache_reopen(cache);
 123 }
 124
 125 void cache_reopen(struct cache_file_entry *cache) {
 126         cache_close(cache);
 127         cache->fd=open(cache->pathname,O_RDWR | O_CREAT,S_IRWXU);
 128 }
 129
 130 void cache_create(struct cache_file_entry *cache, int readahead_window)
 131 {
 132         if (cache->status != CACHE_NONE && cache->fd<0) {
 133                 mkpath(cache->context->root, cache->context->prefix, S_IRWXU);
 134                 cache->pathname=talloc_asprintf(cache, "%s/%s",
 135                                                                                           cache->context->root,
 136                                                                                           cache->cache_name);
 137                 cache_reopen(cache);
 138         }
 139         cache->readahead_window=readahead_window;
 140 }
 141
 142 void cache_new_file(struct cache_file_entry * cache, struct proxy_file *f,
 143                                         const char* filename,
 144                                         int readahead_window, bool oplock)
 145 {
 146         cache->f=f;
 147         cache->fd=-1;
 148         cache->status=CACHE_FILL | CACHE_READ_AHEAD;
 149         DEBUG(5,("NEW CACHE FILE %x oplock %x\n",cache->status,oplock));
 150         if (oplock) cache->status|=CACHE_READ | CACHE_VALIDATE;
 151         cache_create(cache, readahead_window);
 152 }
 153
 154 void cache_file_state(struct cache_file_entry * cache, cache_state state)
 155 {
 156         cache->status=state;
 157 }
 158
 159 static ssize_t flen(int fd)
 160 {
 161         struct stat stats;
 162
 163         if (fstat(fd, &stats)==0) {
 164                 return (ssize_t)stats.st_size;
 165         }
 166         return -1;
 167 }
 168
 169 ssize_t cache_len(struct cache_file_entry *cache)
 170 {
 171         return flen(cache->fd);
 172 }
 173
 174 void cache_validated(struct cache_file_entry *cache, off_t offset)
 175 {
 176         if (cache->validated_extent <= offset) {
 177                 cache->validated_extent=offset;
 178         }
 179         if (cache->readahead_extent < offset) {
 180                 cache->readahead_extent=offset;
 181         }
 182 }
 183
 184 void cache_save(struct cache_file_entry *cache, const uint8_t* data, ssize_t size, off_t offset)
 185 {
 186         if (cache && size > 0 && cache->status & CACHE_FILL) {
 187                 off_t len;
 188                 ssize_t written;
 189                 if (cache->fd < 0) return;
 190
 191                 DEBUG(1,("Consider saving in cache\n"));
 192                 /* until we manage sparse caching, the offset must be within, or adjacent
 193                  * to what has been cached, without an intervening gap - as we have no way
 194                  * of encoding that the gap is not valid cache */
 195                 len=flen(cache->fd);
 196                 if (offset <= len+1 && lseek(cache->fd, offset, SEEK_SET)>=0) {
 197                         /* save cache value */
 198                         written=write(cache->fd, data, size);
 199                         /* only extend the validated extent if the cache is good for reading from */
 200                         if (cache->status & CACHE_READ && cache->validated_extent < (offset + size)
 201                             /* but don't extend if it would leave unvalidated gaps */
 202                             && cache->validated_extent >= offset)
 203                                 cache->validated_extent=offset + size;
 204                         DEBUG(CACHE_DEBUG_LEVEL,("Save cache written at %d %d bytes\n",(int)offset,(int)written));
 205
 206                         if (cache->readahead_extent < offset+size) {
 207                                 cache->readahead_extent=offset+size;
 208                         }
 209                 } else DEBUG(CACHE_DEBUG_LEVEL,("No sparse cache support, ignoring write at %d which is beyond %d\n",(int)offset,(int)len));
 210         } else DEBUG(CACHE_DEBUG_LEVEL,("No caching on file\n"));
 211 }
 212
 213 ssize_t cache_raw_read(struct cache_file_entry *cache, uint8_t* data, off_t offset, ssize_t size)
 214 {
 215         return pread(cache->fd, data, size, offset);
 216 }
 217
 218 /* This function should track changes in rawreadwrite.c/smb_raw_read_send */
 219 NTSTATUS cache_smb_raw_read(struct cache_file_entry *cache,
 220                                 struct ntvfs_module_context *ntvfs,
 221                                 struct ntvfs_request *req,
 222                                 union smb_read *rd,
 223                                 ssize_t* validated)
 224 {
 225         /* Based on pvfs_read.c/pvfs-read */
 226         ssize_t ret;
 227         uint32_t maxcnt;
 228         uint32_t mask;
 229         off_t len;
 230
 231         if (validated) *validated=0;
 232
 233         DEBUG(CACHE_DEBUG_LEVEL,("Actually trying to read from the cache len %d offset %d\n",(int)rd->generic.in.maxcnt,(int)rd->generic.in.offset));
 234         /* Can we actually read ahead on this file anyway? */
 235         if (! cache) {
 236                 DEBUG(CACHE_DEBUG_LEVEL,("Not a valid cache\n"));
 237                 return NT_STATUS_UNSUCCESSFUL;
 238         }
 239
 240         if (cache->fd < 0) {
 241                 return NT_STATUS_INVALID_HANDLE;
 242         }
 243
 244         if (! (cache->status & CACHE_READ) ) {
 245                 DEBUG(CACHE_DEBUG_LEVEL,("Cache %s not in read mode: %x\n",cache->cache_name, cache->status));
 246                 return NT_STATUS_UNSUCCESSFUL;
 247         }
 248
 249         /* mapping should have been done by caller */
 250         if (rd->generic.level != RAW_READ_READX) {
 251                 return NT_STATUS_INVALID_LEVEL;
 252         }
 253
 254         mask = SEC_FILE_READ_DATA;
 255         if (rd->generic.in.read_for_execute) {
 256                 mask |= SEC_FILE_EXECUTE;
 257         }
 258 #warning need to check access mask
 259 /*      if (!(f->access_mask & mask)) {
 260                 return NT_STATUS_ACCESS_DENIED;
 261         }
 262 */
 263         maxcnt = rd->generic.in.maxcnt;
 264         if (maxcnt > UINT16_MAX && req->ctx->protocol < PROTOCOL_SMB2) {
 265                 maxcnt = 0;
 266         }
 267
 268         len=flen(cache->fd);
 269         /* if read would return 0 bytes then we must fail unless we know the cache is fully populated */
 270         if (/*! fully-populated && */rd->generic.in.offset >= len) {
 271                 DEBUG(CACHE_DEBUG_LEVEL,("Can't read %d bytes from position %d which is %d beyond cache length %d\n",(int)maxcnt,(int)rd->generic.in.offset,(int)(maxcnt + rd->generic.in.offset - len),(int)len));
 272                 return NT_STATUS_UNSUCCESSFUL;
 273         }
 274
 275 #warning need to check locks
 276         /* er... I guess we need to be spying on locks, or something */
 277         /*
 278         status = pvfs_check_lock(pvfs, f, req->smbpid,
 279                                  rd->generic.in.offset,
 280                                  maxcnt,
 281                                  READ_LOCK);
 282         if (!NT_STATUS_IS_OK(status)) {
 283                 return status;
 284         }
 285         */
 286
 287         ret = pread(cache->fd,
 288                     rd->generic.out.data,
 289                     maxcnt,
 290                     rd->generic.in.offset);
 291
 292         if (ret == -1) {
 293                 int e=errno;
 294                 /* Why do I assume it is running on a unix? */
 295                 DEBUG(CACHE_DEBUG_LEVEL,("Error %x Read %d bytes from cache offset %d\n",e,ret,(int)rd->generic.in.offset));
 296                 return map_nt_error_from_unix(e);
 297         }
 298
 299         /* Does the cache need to do handle position tracking? */
 300         /* f->handle->position = f->handle->seek_offset = rd->generic.in.offset + ret; */
 301
 302         rd->generic.out.nread = ret;
 303         rd->generic.out.remaining = 0xFFFF;
 304         rd->generic.out.compaction_mode = 0;
 305
 306         /* How much of what we have is validated cache? */
 307         if (! validated); /* just yawn */
 308         else if (cache->validated_extent < rd->generic.in.offset)
 309                 *validated=0;
 310         else if (cache->validated_extent >= rd->generic.in.offset +
 311                         rd->generic.out.nread)
 312                 *validated=rd->generic.out.nread;
 313         else *validated=cache->validated_extent - rd->generic.in.offset;
 314
 315         DEBUG(CACHE_DEBUG_LEVEL,("Cache successfully read %d bytes validated %d\n",(int)ret, (int)((validated)?(*validated):-1) ));
 316
 317         return NT_STATUS_OK;
 318 }
 319
 320 /* Take MD5 checksum of part of cache file */
 321 NTSTATUS cache_smb_raw_checksum(struct cache_file_entry *cache,
 322                                 offset_t offset, ssize_t* length, uint8_t digest[16])
 323 {
 324         struct MD5Context context;
 325         int ret=0;
 326         ssize_t completed=0;
 327         ssize_t remaining=*length;
 328 #define buffer_size 4096
 329         uint8_t buffer[buffer_size];
 330
 331         MD5Init(&context);
 332
 333         while(remaining>0) {
 334                 ret = pread(cache->fd, buffer, MIN(buffer_size, remaining), offset);
 335                 if (ret<=0) break;
 336                 completed+=ret;
 337                 offset+=ret;
 338                 remaining-=ret;
 339                 MD5Update(&context, buffer, ret);
 340         }
 341
 342         MD5Final(digest, &context);
 343         *length=completed;
 344
 345         if (length==0) return NT_STATUS_UNSUCCESSFUL;
 346         return NT_STATUS_OK;
 347 }
 348
 349 /* Set up caching. We want to pass a reference to the file we opened as
 350  * part of the cache key. We see this note in interfaces.h:
 351                 NOTE: fname can also be a pointer to a
 352                  uint64_t file_id if create_options has the
 353                  NTCREATEX_OPTIONS_OPEN_BY_FILE_ID flag set
 354  * which is nice! We need to notice! */
 355
 356 struct cache_file_entry * cache_filename_open(struct cache_context *cache_context,
 357                                                                          struct proxy_file *f,
 358                                                                          const char* filename,
 359                                                                          bool oplock,
 360                                                                          int readahead_window)
 361 {
 362         struct cache_file_entry *cache=talloc_zero(f, struct cache_file_entry);
 363
 364         if (cache) {
 365                 cache->context=talloc_reference(cache, cache_context);
 366                 cache->cache_name=talloc_asprintf(cache,"%s/cache-%d-f-%s",
 367                                                                                   cache->context->prefix,0,filename);
 368                 DEBUG(1,("Session %d open proxied for file: %s, cache %s RA %d\n",
 369                                  0, filename, cache->cache_name, readahead_window));
 370
 371                 cache_new_file(cache, f, cache->cache_name, readahead_window, oplock);
 372         }
 373         return cache;
 374 }
 375
 376 struct cache_file_entry * cache_fileid_open(struct cache_context *cache_context,
 377                                                                          struct proxy_file *f,
 378                                                                          const uint64_t* id,
 379                                                                          bool oplock,
 380                                                                          int readahead_window)
 381 {
 382
 383         struct cache_file_entry *cache=talloc_zero(f, struct cache_file_entry);
 384
 385         if (cache) {
 386                 cache->context=talloc_reference(cache, cache_context);
 387                 cache->cache_name=talloc_asprintf(cache,"%s/cache-%d-id-%lld",
 388                                                                                   cache->context->prefix,0,*id);
 389                 DEBUG(1,("Session %d open proxied for file-id: %lld, cache %s RA %d\n",
 390                                  0, *id,cache->cache_name, readahead_window));
 391
 392                 cache_new_file(cache, f, cache->cache_name, readahead_window, oplock);
 393         }
 394         return cache;
 395 }