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Diffstat (limited to 'src/fs/fs_directory.c')
| -rw-r--r-- | src/fs/fs_directory.c | 644 |
1 files changed, 644 insertions, 0 deletions
diff --git a/src/fs/fs_directory.c b/src/fs/fs_directory.c new file mode 100644 index 0000000..b26ec12 --- /dev/null +++ b/src/fs/fs_directory.c @@ -0,0 +1,644 @@ +/* + This file is part of GNUnet. + (C) 2003, 2004, 2006, 2009 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file fs/fs_directory.c + * @brief Helper functions for building directories. + * @author Christian Grothoff + * + * TODO: + * - modify directory builder API to support incremental + * generation of directories (to allow directories that + * would not fit into memory to be created) + * - modify directory processor API to support incremental + * iteration over FULL directories (without missing entries) + * to allow access to directories that do not fit entirely + * into memory + */ +#include "platform.h" +#include "gnunet_fs_service.h" +#include "fs_api.h" + +/** + * String that is used to indicate that a file + * is a GNUnet directory. + */ +#define GNUNET_DIRECTORY_MAGIC "\211GND\r\n\032\n" + + +/** + * Does the meta-data claim that this is a directory? + * Checks if the mime-type is that of a GNUnet directory. + * + * @return GNUNET_YES if it is, GNUNET_NO if it is not, GNUNET_SYSERR if + * we have no mime-type information (treat as 'GNUNET_NO') + */ +int +GNUNET_FS_meta_data_test_for_directory (const struct GNUNET_CONTAINER_MetaData + *md) +{ + char *mime; + int ret; + + if (NULL == md) + return GNUNET_SYSERR; + mime = + GNUNET_CONTAINER_meta_data_get_by_type (md, EXTRACTOR_METATYPE_MIMETYPE); + if (mime == NULL) + return GNUNET_SYSERR; + ret = (0 == strcmp (mime, GNUNET_FS_DIRECTORY_MIME)) ? GNUNET_YES : GNUNET_NO; + GNUNET_free (mime); + return ret; +} + + +/** + * Set the MIMETYPE information for the given + * metadata to "application/gnunet-directory". + * + * @param md metadata to add mimetype to + */ +void +GNUNET_FS_meta_data_make_directory (struct GNUNET_CONTAINER_MetaData *md) +{ + char *mime; + + mime = + GNUNET_CONTAINER_meta_data_get_by_type (md, EXTRACTOR_METATYPE_MIMETYPE); + if (mime != NULL) + { + GNUNET_break (0 == strcmp (mime, GNUNET_FS_DIRECTORY_MIME)); + GNUNET_free (mime); + return; + } + GNUNET_CONTAINER_meta_data_insert (md, "<gnunet>", + EXTRACTOR_METATYPE_MIMETYPE, + EXTRACTOR_METAFORMAT_UTF8, "text/plain", + GNUNET_FS_DIRECTORY_MIME, + strlen (GNUNET_FS_DIRECTORY_MIME) + 1); +} + + +/** + * Closure for 'find_full_data'. + */ +struct GetFullDataClosure +{ + + /** + * Extracted binary meta data. + */ + void *data; + + /** + * Number of bytes stored in data. + */ + size_t size; +}; + + +/** + * Type of a function that libextractor calls for each + * meta data item found. + * + * @param cls closure (user-defined) + * @param plugin_name name of the plugin that produced this value; + * special values can be used (i.e. '<zlib>' for zlib being + * used in the main libextractor library and yielding + * meta data). + * @param type libextractor-type describing the meta data + * @param format basic format information about data + * @param data_mime_type mime-type of data (not of the original file); + * can be NULL (if mime-type is not known) + * @param data actual meta-data found + * @param data_len number of bytes in data + * @return 0 to continue extracting, 1 to abort + */ +static int +find_full_data (void *cls, const char *plugin_name, + enum EXTRACTOR_MetaType type, enum EXTRACTOR_MetaFormat format, + const char *data_mime_type, const char *data, size_t data_len) +{ + struct GetFullDataClosure *gfdc = cls; + + if (type == EXTRACTOR_METATYPE_GNUNET_FULL_DATA) + { + gfdc->size = data_len; + if (data_len > 0) + { + gfdc->data = GNUNET_malloc (data_len); + memcpy (gfdc->data, data, data_len); + } + return 1; + } + return 0; +} + + +/** + * Iterate over all entries in a directory. Note that directories + * are structured such that it is possible to iterate over the + * individual blocks as well as over the entire directory. Thus + * a client can call this function on the buffer in the + * GNUNET_FS_ProgressCallback. Also, directories can optionally + * include the contents of (small) files embedded in the directory + * itself; for those files, the processor may be given the + * contents of the file directly by this function. + * <p> + * + * Note that this function maybe called on parts of directories. Thus + * parser errors should not be reported _at all_ (with GNUNET_break). + * Still, if some entries can be recovered despite these parsing + * errors, the function should try to do this. + * + * @param size number of bytes in data + * @param data pointer to the beginning of the directory + * @param offset offset of data in the directory + * @param dep function to call on each entry + * @param dep_cls closure for dep + * @return GNUNET_OK if this could be a block in a directory, + * GNUNET_NO if this could be part of a directory (but not 100% OK) + * GNUNET_SYSERR if 'data' does not represent a directory + */ +int +GNUNET_FS_directory_list_contents (size_t size, const void *data, + uint64_t offset, + GNUNET_FS_DirectoryEntryProcessor dep, + void *dep_cls) +{ + struct GetFullDataClosure full_data; + const char *cdata = data; + char *emsg; + uint64_t pos; + uint64_t align; + uint32_t mdSize; + uint64_t epos; + struct GNUNET_FS_Uri *uri; + struct GNUNET_CONTAINER_MetaData *md; + char *filename; + + if ((offset == 0) && + ((size < 8 + sizeof (uint32_t)) || + (0 != memcmp (cdata, GNUNET_FS_DIRECTORY_MAGIC, 8)))) + return GNUNET_SYSERR; + pos = offset; + if (offset == 0) + { + memcpy (&mdSize, &cdata[8], sizeof (uint32_t)); + mdSize = ntohl (mdSize); + if (mdSize > size - 8 - sizeof (uint32_t)) + { + /* invalid size */ + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("MAGIC mismatch. This is not a GNUnet directory.\n")); + return GNUNET_SYSERR; + } + md = GNUNET_CONTAINER_meta_data_deserialize (&cdata[8 + sizeof (uint32_t)], + mdSize); + if (md == NULL) + { + GNUNET_break (0); + return GNUNET_SYSERR; /* malformed ! */ + } + dep (dep_cls, NULL, NULL, md, 0, NULL); + GNUNET_CONTAINER_meta_data_destroy (md); + pos = 8 + sizeof (uint32_t) + mdSize; + } + while (pos < size) + { + /* find end of URI */ + if (cdata[pos] == '\0') + { + /* URI is never empty, must be end of block, + * skip to next alignment */ + align = ((pos / DBLOCK_SIZE) + 1) * DBLOCK_SIZE; + if (align == pos) + { + /* if we were already aligned, still skip a block! */ + align += DBLOCK_SIZE; + } + pos = align; + if (pos >= size) + { + /* malformed - or partial download... */ + break; + } + } + epos = pos; + while ((epos < size) && (cdata[epos] != '\0')) + epos++; + if (epos >= size) + return GNUNET_NO; /* malformed - or partial download */ + + uri = GNUNET_FS_uri_parse (&cdata[pos], &emsg); + pos = epos + 1; + if (uri == NULL) + { + GNUNET_free (emsg); + pos--; /* go back to '\0' to force going to next alignment */ + continue; + } + if (GNUNET_FS_uri_test_ksk (uri)) + { + GNUNET_FS_uri_destroy (uri); + GNUNET_break (0); + return GNUNET_NO; /* illegal in directory! */ + } + + memcpy (&mdSize, &cdata[pos], sizeof (uint32_t)); + mdSize = ntohl (mdSize); + pos += sizeof (uint32_t); + if (pos + mdSize > size) + { + GNUNET_FS_uri_destroy (uri); + return GNUNET_NO; /* malformed - or partial download */ + } + + md = GNUNET_CONTAINER_meta_data_deserialize (&cdata[pos], mdSize); + if (md == NULL) + { + GNUNET_FS_uri_destroy (uri); + GNUNET_break (0); + return GNUNET_NO; /* malformed ! */ + } + pos += mdSize; + filename = + GNUNET_CONTAINER_meta_data_get_by_type (md, + EXTRACTOR_METATYPE_GNUNET_ORIGINAL_FILENAME); + full_data.size = 0; + full_data.data = NULL; + GNUNET_CONTAINER_meta_data_iterate (md, &find_full_data, &full_data); + if (dep != NULL) + { + dep (dep_cls, filename, uri, md, full_data.size, full_data.data); + } + GNUNET_free_non_null (full_data.data); + GNUNET_free_non_null (filename); + GNUNET_CONTAINER_meta_data_destroy (md); + GNUNET_FS_uri_destroy (uri); + } + return GNUNET_OK; +} + +/** + * Entries in the directory (builder). + */ +struct BuilderEntry +{ + /** + * This is a linked list. + */ + struct BuilderEntry *next; + + /** + * Length of this entry. + */ + size_t len; +}; + +/** + * Internal state of a directory builder. + */ +struct GNUNET_FS_DirectoryBuilder +{ + /** + * Meta-data for the directory itself. + */ + struct GNUNET_CONTAINER_MetaData *meta; + + /** + * Head of linked list of entries. + */ + struct BuilderEntry *head; + + /** + * Number of entires in the directory. + */ + unsigned int count; +}; + + +/** + * Create a directory builder. + * + * @param mdir metadata for the directory + */ +struct GNUNET_FS_DirectoryBuilder * +GNUNET_FS_directory_builder_create (const struct GNUNET_CONTAINER_MetaData + *mdir) +{ + struct GNUNET_FS_DirectoryBuilder *ret; + + ret = GNUNET_malloc (sizeof (struct GNUNET_FS_DirectoryBuilder)); + if (mdir != NULL) + ret->meta = GNUNET_CONTAINER_meta_data_duplicate (mdir); + else + ret->meta = GNUNET_CONTAINER_meta_data_create (); + GNUNET_FS_meta_data_make_directory (ret->meta); + return ret; +} + + +/** + * Add an entry to a directory. + * + * @param bld directory to extend + * @param uri uri of the entry (must not be a KSK) + * @param md metadata of the entry + * @param data raw data of the entry, can be NULL, otherwise + * data must point to exactly the number of bytes specified + * by the uri which must be of type LOC or CHK + */ +void +GNUNET_FS_directory_builder_add (struct GNUNET_FS_DirectoryBuilder *bld, + const struct GNUNET_FS_Uri *uri, + const struct GNUNET_CONTAINER_MetaData *md, + const void *data) +{ + struct GNUNET_FS_Uri *curi; + struct BuilderEntry *e; + uint64_t fsize; + uint32_t big; + ssize_t ret; + size_t mds; + size_t mdxs; + char *uris; + char *ser; + char *sptr; + size_t slen; + struct GNUNET_CONTAINER_MetaData *meta; + const struct GNUNET_CONTAINER_MetaData *meta_use; + + GNUNET_assert (!GNUNET_FS_uri_test_ksk (uri)); + if (NULL != data) + { + GNUNET_assert (!GNUNET_FS_uri_test_sks (uri)); + if (GNUNET_FS_uri_test_chk (uri)) + { + fsize = GNUNET_FS_uri_chk_get_file_size (uri); + } + else + { + curi = GNUNET_FS_uri_loc_get_uri (uri); + GNUNET_assert (NULL != curi); + fsize = GNUNET_FS_uri_chk_get_file_size (curi); + GNUNET_FS_uri_destroy (curi); + } + } + else + { + fsize = 0; /* not given */ + } + if (fsize > MAX_INLINE_SIZE) + fsize = 0; /* too large */ + uris = GNUNET_FS_uri_to_string (uri); + slen = strlen (uris) + 1; + mds = GNUNET_CONTAINER_meta_data_get_serialized_size (md); + meta_use = md; + meta = NULL; + if (fsize > 0) + { + meta = GNUNET_CONTAINER_meta_data_duplicate (md); + GNUNET_CONTAINER_meta_data_insert (meta, "<gnunet>", + EXTRACTOR_METATYPE_GNUNET_FULL_DATA, + EXTRACTOR_METAFORMAT_BINARY, NULL, data, + fsize); + mdxs = GNUNET_CONTAINER_meta_data_get_serialized_size (meta); + if ((slen + sizeof (uint32_t) + mdxs - 1) / DBLOCK_SIZE == + (slen + sizeof (uint32_t) + mds - 1) / DBLOCK_SIZE) + { + /* adding full data would not cause us to cross + * additional blocks, so add it! */ + meta_use = meta; + mds = mdxs; + } + } + + if (mds > GNUNET_MAX_MALLOC_CHECKED / 2) + mds = GNUNET_MAX_MALLOC_CHECKED / 2; + e = GNUNET_malloc (sizeof (struct BuilderEntry) + slen + mds + + sizeof (uint32_t)); + ser = (char *) &e[1]; + memcpy (ser, uris, slen); + GNUNET_free (uris); + sptr = &ser[slen + sizeof (uint32_t)]; + ret = + GNUNET_CONTAINER_meta_data_serialize (meta_use, &sptr, mds, + GNUNET_CONTAINER_META_DATA_SERIALIZE_PART); + if (NULL != meta) + GNUNET_CONTAINER_meta_data_destroy (meta); + if (ret == -1) + mds = 0; + else + mds = ret; + big = htonl (mds); + memcpy (&ser[slen], &big, sizeof (uint32_t)); + e->len = slen + sizeof (uint32_t) + mds; + e->next = bld->head; + bld->head = e; + bld->count++; +} + + +/** + * Given the start and end position of a block of + * data, return the end position of that data + * after alignment to the DBLOCK_SIZE. + */ +static size_t +do_align (size_t start_position, size_t end_position) +{ + size_t align; + + align = (end_position / DBLOCK_SIZE) * DBLOCK_SIZE; + if ((start_position < align) && (end_position > align)) + return align + end_position - start_position; + return end_position; +} + + +/** + * Compute a permuation of the blocks to + * minimize the cost of alignment. Greedy packer. + * + * @param start starting position for the first block + * @param count size of the two arrays + * @param sizes the sizes of the individual blocks + * @param perm the permutation of the blocks (updated) + */ +static void +block_align (size_t start, unsigned int count, const size_t * sizes, + unsigned int *perm) +{ + unsigned int i; + unsigned int j; + unsigned int tmp; + unsigned int best; + ssize_t badness; + size_t cpos; + size_t cend; + ssize_t cbad; + unsigned int cval; + + cpos = start; + for (i = 0; i < count; i++) + { + start = cpos; + badness = 0x7FFFFFFF; + best = -1; + for (j = i; j < count; j++) + { + cval = perm[j]; + cend = cpos + sizes[cval]; + if (cpos % DBLOCK_SIZE == 0) + { + /* prefer placing the largest blocks first */ + cbad = -(cend % DBLOCK_SIZE); + } + else + { + if (cpos / DBLOCK_SIZE == cend / DBLOCK_SIZE) + { + /* Data fits into the same block! Prefer small left-overs! */ + cbad = DBLOCK_SIZE - cend % DBLOCK_SIZE; + } + else + { + /* Would have to waste space to re-align, add big factor, this + * case is a real loss (proportional to space wasted)! */ + cbad = DBLOCK_SIZE * (DBLOCK_SIZE - cpos % DBLOCK_SIZE); + } + } + if (cbad < badness) + { + best = j; + badness = cbad; + } + } + GNUNET_assert (best != -1); + tmp = perm[i]; + perm[i] = perm[best]; + perm[best] = tmp; + cpos += sizes[perm[i]]; + cpos = do_align (start, cpos); + } +} + + +/** + * Finish building the directory. Frees the + * builder context and returns the directory + * in-memory. + * + * @param bld directory to finish + * @param rsize set to the number of bytes needed + * @param rdata set to the encoded directory + * @return GNUNET_OK on success + */ +int +GNUNET_FS_directory_builder_finish (struct GNUNET_FS_DirectoryBuilder *bld, + size_t * rsize, void **rdata) +{ + char *data; + char *sptr; + size_t *sizes; + unsigned int *perm; + unsigned int i; + unsigned int j; + struct BuilderEntry *pos; + struct BuilderEntry **bes; + size_t size; + size_t psize; + size_t off; + ssize_t ret; + uint32_t big; + + size = strlen (GNUNET_DIRECTORY_MAGIC) + sizeof (uint32_t); + size += GNUNET_CONTAINER_meta_data_get_serialized_size (bld->meta); + sizes = NULL; + perm = NULL; + bes = NULL; + if (0 < bld->count) + { + sizes = GNUNET_malloc (bld->count * sizeof (size_t)); + perm = GNUNET_malloc (bld->count * sizeof (unsigned int)); + bes = GNUNET_malloc (bld->count * sizeof (struct BuilderEntry *)); + pos = bld->head; + for (i = 0; i < bld->count; i++) + { + perm[i] = i; + bes[i] = pos; + sizes[i] = pos->len; + pos = pos->next; + } + block_align (size, bld->count, sizes, perm); + /* compute final size with alignment */ + for (i = 0; i < bld->count; i++) + { + psize = size; + size += sizes[perm[i]]; + size = do_align (psize, size); + } + } + *rsize = size; + data = GNUNET_malloc_large (size); + if (data == NULL) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "malloc"); + *rsize = 0; + *rdata = NULL; + GNUNET_free_non_null (sizes); + GNUNET_free_non_null (perm); + GNUNET_free_non_null (bes); + return GNUNET_SYSERR; + } + *rdata = data; + memcpy (data, GNUNET_DIRECTORY_MAGIC, strlen (GNUNET_DIRECTORY_MAGIC)); + off = strlen (GNUNET_DIRECTORY_MAGIC); + + sptr = &data[off + sizeof (uint32_t)]; + ret = + GNUNET_CONTAINER_meta_data_serialize (bld->meta, &sptr, + size - off - sizeof (uint32_t), + GNUNET_CONTAINER_META_DATA_SERIALIZE_FULL); + GNUNET_assert (ret != -1); + big = htonl (ret); + memcpy (&data[off], &big, sizeof (uint32_t)); + off += sizeof (uint32_t) + ret; + for (j = 0; j < bld->count; j++) + { + i = perm[j]; + psize = off; + off += sizes[i]; + off = do_align (psize, off); + memcpy (&data[off - sizes[i]], &(bes[i])[1], sizes[i]); + GNUNET_free (bes[i]); + } + GNUNET_free_non_null (sizes); + GNUNET_free_non_null (perm); + GNUNET_free_non_null (bes); + GNUNET_assert (off == size); + GNUNET_CONTAINER_meta_data_destroy (bld->meta); + GNUNET_free (bld); + return GNUNET_OK; +} + + +/* end of fs_directory.c */ |