+++ /dev/null
- /*
- Unix SMB/CIFS implementation.
-
- trivial database library
-
- Copyright (C) Andrew Tridgell 1999-2005
- Copyright (C) Paul `Rusty' Russell 2000
- Copyright (C) Jeremy Allison 2000-2003
- Copyright (C) Rusty Russell 2010
-
- ** NOTE! The following LGPL license applies to the tdb
- ** library. This does NOT imply that all of Samba is released
- ** under the LGPL
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 3 of the License, or (at your option) any later version.
-
- This library 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, see <http://www.gnu.org/licenses/>.
-*/
-#include "private.h"
-#include <assert.h>
-#include <ccan/likely/likely.h>
-
-void tdb_munmap(struct tdb_file *file)
-{
- if (file->fd == -1)
- return;
-
- if (file->map_ptr) {
- munmap(file->map_ptr, file->map_size);
- file->map_ptr = NULL;
- }
-}
-
-void tdb_mmap(struct tdb_context *tdb)
-{
- int mmap_flags;
-
- if (tdb->flags & TDB_INTERNAL)
- return;
-
- if (tdb->flags & TDB_NOMMAP)
- return;
-
- if ((tdb->open_flags & O_ACCMODE) == O_RDONLY)
- mmap_flags = PROT_READ;
- else
- mmap_flags = PROT_READ | PROT_WRITE;
-
- /* size_t can be smaller than off_t. */
- if ((size_t)tdb->file->map_size == tdb->file->map_size) {
- tdb->file->map_ptr = mmap(NULL, tdb->file->map_size,
- mmap_flags,
- MAP_SHARED, tdb->file->fd, 0);
- } else
- tdb->file->map_ptr = MAP_FAILED;
-
- /*
- * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
- */
- if (tdb->file->map_ptr == MAP_FAILED) {
- tdb->file->map_ptr = NULL;
- tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
- "tdb_mmap failed for size %lld (%s)",
- (long long)tdb->file->map_size, strerror(errno));
- }
-}
-
-/* check for an out of bounds access - if it is out of bounds then
- see if the database has been expanded by someone else and expand
- if necessary
- note that "len" is the minimum length needed for the db.
-
- If probe is true, len being too large isn't a failure.
-*/
-static enum TDB_ERROR tdb_oob(struct tdb_context *tdb,
- tdb_off_t off, tdb_len_t len, bool probe)
-{
- struct stat st;
- enum TDB_ERROR ecode;
-
- /* We can't hold pointers during this: we could unmap! */
- assert(!tdb->tdb2.direct_access
- || (tdb->flags & TDB_NOLOCK)
- || tdb_has_expansion_lock(tdb));
-
- if (len + off < len) {
- if (probe)
- return TDB_SUCCESS;
-
- return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "tdb_oob off %llu len %llu wrap\n",
- (long long)off, (long long)len);
- }
-
- if (len + off <= tdb->file->map_size)
- return TDB_SUCCESS;
- if (tdb->flags & TDB_INTERNAL) {
- if (probe)
- return TDB_SUCCESS;
-
- tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "tdb_oob len %lld beyond internal"
- " malloc size %lld",
- (long long)(off + len),
- (long long)tdb->file->map_size);
- return TDB_ERR_IO;
- }
-
- ecode = tdb_lock_expand(tdb, F_RDLCK);
- if (ecode != TDB_SUCCESS) {
- return ecode;
- }
-
- if (fstat(tdb->file->fd, &st) != 0) {
- tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "Failed to fstat file: %s", strerror(errno));
- tdb_unlock_expand(tdb, F_RDLCK);
- return TDB_ERR_IO;
- }
-
- tdb_unlock_expand(tdb, F_RDLCK);
-
- if (st.st_size < off + len) {
- if (probe)
- return TDB_SUCCESS;
-
- tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "tdb_oob len %llu beyond eof at %zu",
- (long long)(off + len), st.st_size);
- return TDB_ERR_IO;
- }
-
- /* Unmap, update size, remap */
- tdb_munmap(tdb->file);
-
- tdb->file->map_size = st.st_size;
- tdb_mmap(tdb);
- return TDB_SUCCESS;
-}
-
-/* Endian conversion: we only ever deal with 8 byte quantities */
-void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size)
-{
- assert(size % 8 == 0);
- if (unlikely((tdb->flags & TDB_CONVERT)) && buf) {
- uint64_t i, *p = (uint64_t *)buf;
- for (i = 0; i < size / 8; i++)
- p[i] = bswap_64(p[i]);
- }
- return buf;
-}
-
-/* Return first non-zero offset in offset array, or end, or -ve error. */
-/* FIXME: Return the off? */
-uint64_t tdb_find_nonzero_off(struct tdb_context *tdb,
- tdb_off_t base, uint64_t start, uint64_t end)
-{
- uint64_t i;
- const uint64_t *val;
-
- /* Zero vs non-zero is the same unconverted: minor optimization. */
- val = tdb_access_read(tdb, base + start * sizeof(tdb_off_t),
- (end - start) * sizeof(tdb_off_t), false);
- if (TDB_PTR_IS_ERR(val)) {
- return TDB_ERR_TO_OFF(TDB_PTR_ERR(val));
- }
-
- for (i = 0; i < (end - start); i++) {
- if (val[i])
- break;
- }
- tdb_access_release(tdb, val);
- return start + i;
-}
-
-/* Return first zero offset in num offset array, or num, or -ve error. */
-uint64_t tdb_find_zero_off(struct tdb_context *tdb, tdb_off_t off,
- uint64_t num)
-{
- uint64_t i;
- const uint64_t *val;
-
- /* Zero vs non-zero is the same unconverted: minor optimization. */
- val = tdb_access_read(tdb, off, num * sizeof(tdb_off_t), false);
- if (TDB_PTR_IS_ERR(val)) {
- return TDB_ERR_TO_OFF(TDB_PTR_ERR(val));
- }
-
- for (i = 0; i < num; i++) {
- if (!val[i])
- break;
- }
- tdb_access_release(tdb, val);
- return i;
-}
-
-enum TDB_ERROR zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len)
-{
- char buf[8192] = { 0 };
- void *p = tdb->tdb2.io->direct(tdb, off, len, true);
- enum TDB_ERROR ecode = TDB_SUCCESS;
-
- assert(!(tdb->flags & TDB_RDONLY));
- if (TDB_PTR_IS_ERR(p)) {
- return TDB_PTR_ERR(p);
- }
- if (p) {
- memset(p, 0, len);
- return ecode;
- }
- while (len) {
- unsigned todo = len < sizeof(buf) ? len : sizeof(buf);
- ecode = tdb->tdb2.io->twrite(tdb, off, buf, todo);
- if (ecode != TDB_SUCCESS) {
- break;
- }
- len -= todo;
- off += todo;
- }
- return ecode;
-}
-
-tdb_off_t tdb_read_off(struct tdb_context *tdb, tdb_off_t off)
-{
- tdb_off_t ret;
- enum TDB_ERROR ecode;
-
- if (likely(!(tdb->flags & TDB_CONVERT))) {
- tdb_off_t *p = tdb->tdb2.io->direct(tdb, off, sizeof(*p),
- false);
- if (TDB_PTR_IS_ERR(p)) {
- return TDB_ERR_TO_OFF(TDB_PTR_ERR(p));
- }
- if (p)
- return *p;
- }
-
- ecode = tdb_read_convert(tdb, off, &ret, sizeof(ret));
- if (ecode != TDB_SUCCESS) {
- return TDB_ERR_TO_OFF(ecode);
- }
- return ret;
-}
-
-/* write a lump of data at a specified offset */
-static enum TDB_ERROR tdb_write(struct tdb_context *tdb, tdb_off_t off,
- const void *buf, tdb_len_t len)
-{
- enum TDB_ERROR ecode;
-
- if (tdb->flags & TDB_RDONLY) {
- return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
- "Write to read-only database");
- }
-
- ecode = tdb->tdb2.io->oob(tdb, off, len, false);
- if (ecode != TDB_SUCCESS) {
- return ecode;
- }
-
- if (tdb->file->map_ptr) {
- memcpy(off + (char *)tdb->file->map_ptr, buf, len);
- } else {
- ssize_t ret;
- ret = pwrite(tdb->file->fd, buf, len, off);
- if (ret != len) {
- /* This shouldn't happen: we avoid sparse files. */
- if (ret >= 0)
- errno = ENOSPC;
-
- return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "tdb_write: %zi at %zu len=%zu (%s)",
- ret, (size_t)off, (size_t)len,
- strerror(errno));
- }
- }
- return TDB_SUCCESS;
-}
-
-/* read a lump of data at a specified offset */
-static enum TDB_ERROR tdb_read(struct tdb_context *tdb, tdb_off_t off,
- void *buf, tdb_len_t len)
-{
- enum TDB_ERROR ecode;
-
- ecode = tdb->tdb2.io->oob(tdb, off, len, false);
- if (ecode != TDB_SUCCESS) {
- return ecode;
- }
-
- if (tdb->file->map_ptr) {
- memcpy(buf, off + (char *)tdb->file->map_ptr, len);
- } else {
- ssize_t r = pread(tdb->file->fd, buf, len, off);
- if (r != len) {
- return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "tdb_read failed with %zi at %zu "
- "len=%zu (%s) map_size=%zu",
- r, (size_t)off, (size_t)len,
- strerror(errno),
- (size_t)tdb->file->map_size);
- }
- }
- return TDB_SUCCESS;
-}
-
-enum TDB_ERROR tdb_write_convert(struct tdb_context *tdb, tdb_off_t off,
- const void *rec, size_t len)
-{
- enum TDB_ERROR ecode;
-
- if (unlikely((tdb->flags & TDB_CONVERT))) {
- void *conv = malloc(len);
- if (!conv) {
- return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
- "tdb_write: no memory converting"
- " %zu bytes", len);
- }
- memcpy(conv, rec, len);
- ecode = tdb->tdb2.io->twrite(tdb, off,
- tdb_convert(tdb, conv, len), len);
- free(conv);
- } else {
- ecode = tdb->tdb2.io->twrite(tdb, off, rec, len);
- }
- return ecode;
-}
-
-enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
- void *rec, size_t len)
-{
- enum TDB_ERROR ecode = tdb->tdb2.io->tread(tdb, off, rec, len);
- tdb_convert(tdb, rec, len);
- return ecode;
-}
-
-enum TDB_ERROR tdb_write_off(struct tdb_context *tdb,
- tdb_off_t off, tdb_off_t val)
-{
- if (tdb->flags & TDB_RDONLY) {
- return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
- "Write to read-only database");
- }
-
- if (likely(!(tdb->flags & TDB_CONVERT))) {
- tdb_off_t *p = tdb->tdb2.io->direct(tdb, off, sizeof(*p),
- true);
- if (TDB_PTR_IS_ERR(p)) {
- return TDB_PTR_ERR(p);
- }
- if (p) {
- *p = val;
- return TDB_SUCCESS;
- }
- }
- return tdb_write_convert(tdb, off, &val, sizeof(val));
-}
-
-static void *_tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset,
- tdb_len_t len, unsigned int prefix)
-{
- unsigned char *buf;
- enum TDB_ERROR ecode;
-
- /* some systems don't like zero length malloc */
- buf = malloc(prefix + len ? prefix + len : 1);
- if (!buf) {
- tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_USE_ERROR,
- "tdb_alloc_read malloc failed len=%zu",
- (size_t)(prefix + len));
- return TDB_ERR_PTR(TDB_ERR_OOM);
- } else {
- ecode = tdb->tdb2.io->tread(tdb, offset, buf+prefix, len);
- if (unlikely(ecode != TDB_SUCCESS)) {
- free(buf);
- return TDB_ERR_PTR(ecode);
- }
- }
- return buf;
-}
-
-/* read a lump of data, allocating the space for it */
-void *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len)
-{
- return _tdb_alloc_read(tdb, offset, len, 0);
-}
-
-static enum TDB_ERROR fill(struct tdb_context *tdb,
- const void *buf, size_t size,
- tdb_off_t off, tdb_len_t len)
-{
- while (len) {
- size_t n = len > size ? size : len;
- ssize_t ret = pwrite(tdb->file->fd, buf, n, off);
- if (ret != n) {
- if (ret >= 0)
- errno = ENOSPC;
-
- return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
- "fill failed:"
- " %zi at %zu len=%zu (%s)",
- ret, (size_t)off, (size_t)len,
- strerror(errno));
- }
- len -= n;
- off += n;
- }
- return TDB_SUCCESS;
-}
-
-/* expand a file. we prefer to use ftruncate, as that is what posix
- says to use for mmap expansion */
-static enum TDB_ERROR tdb_expand_file(struct tdb_context *tdb,
- tdb_len_t addition)
-{
- char buf[8192];
- enum TDB_ERROR ecode;
-
- if (tdb->flags & TDB_RDONLY) {
- return tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
- "Expand on read-only database");
- }
-
- if (tdb->flags & TDB_INTERNAL) {
- char *new = realloc(tdb->file->map_ptr,
- tdb->file->map_size + addition);
- if (!new) {
- return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
- "No memory to expand database");
- }
- tdb->file->map_ptr = new;
- tdb->file->map_size += addition;
- } else {
- /* Unmap before trying to write; old TDB claimed OpenBSD had
- * problem with this otherwise. */
- tdb_munmap(tdb->file);
-
- /* If this fails, we try to fill anyway. */
- if (ftruncate(tdb->file->fd, tdb->file->map_size + addition))
- ;
-
- /* now fill the file with something. This ensures that the
- file isn't sparse, which would be very bad if we ran out of
- disk. This must be done with write, not via mmap */
- memset(buf, 0x43, sizeof(buf));
- ecode = fill(tdb, buf, sizeof(buf), tdb->file->map_size,
- addition);
- if (ecode != TDB_SUCCESS)
- return ecode;
- tdb->file->map_size += addition;
- tdb_mmap(tdb);
- }
- return TDB_SUCCESS;
-}
-
-const void *tdb_access_read(struct tdb_context *tdb,
- tdb_off_t off, tdb_len_t len, bool convert)
-{
- void *ret = NULL;
-
- if (likely(!(tdb->flags & TDB_CONVERT))) {
- ret = tdb->tdb2.io->direct(tdb, off, len, false);
-
- if (TDB_PTR_IS_ERR(ret)) {
- return ret;
- }
- }
- if (!ret) {
- struct tdb_access_hdr *hdr;
- hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr));
- if (TDB_PTR_IS_ERR(hdr)) {
- return hdr;
- }
- hdr->next = tdb->tdb2.access;
- tdb->tdb2.access = hdr;
- ret = hdr + 1;
- if (convert) {
- tdb_convert(tdb, (void *)ret, len);
- }
- } else
- tdb->tdb2.direct_access++;
-
- return ret;
-}
-
-void *tdb_access_write(struct tdb_context *tdb,
- tdb_off_t off, tdb_len_t len, bool convert)
-{
- void *ret = NULL;
-
- if (tdb->flags & TDB_RDONLY) {
- tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR,
- "Write to read-only database");
- return TDB_ERR_PTR(TDB_ERR_RDONLY);
- }
-
- if (likely(!(tdb->flags & TDB_CONVERT))) {
- ret = tdb->tdb2.io->direct(tdb, off, len, true);
-
- if (TDB_PTR_IS_ERR(ret)) {
- return ret;
- }
- }
-
- if (!ret) {
- struct tdb_access_hdr *hdr;
- hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr));
- if (TDB_PTR_IS_ERR(hdr)) {
- return hdr;
- }
- hdr->next = tdb->tdb2.access;
- tdb->tdb2.access = hdr;
- hdr->off = off;
- hdr->len = len;
- hdr->convert = convert;
- ret = hdr + 1;
- if (convert)
- tdb_convert(tdb, (void *)ret, len);
- } else
- tdb->tdb2.direct_access++;
-
- return ret;
-}
-
-static struct tdb_access_hdr **find_hdr(struct tdb_context *tdb, const void *p)
-{
- struct tdb_access_hdr **hp;
-
- for (hp = &tdb->tdb2.access; *hp; hp = &(*hp)->next) {
- if (*hp + 1 == p)
- return hp;
- }
- return NULL;
-}
-
-void tdb_access_release(struct tdb_context *tdb, const void *p)
-{
- struct tdb_access_hdr *hdr, **hp = find_hdr(tdb, p);
-
- if (hp) {
- hdr = *hp;
- *hp = hdr->next;
- free(hdr);
- } else
- tdb->tdb2.direct_access--;
-}
-
-enum TDB_ERROR tdb_access_commit(struct tdb_context *tdb, void *p)
-{
- struct tdb_access_hdr *hdr, **hp = find_hdr(tdb, p);
- enum TDB_ERROR ecode;
-
- if (hp) {
- hdr = *hp;
- if (hdr->convert)
- ecode = tdb_write_convert(tdb, hdr->off, p, hdr->len);
- else
- ecode = tdb_write(tdb, hdr->off, p, hdr->len);
- *hp = hdr->next;
- free(hdr);
- } else {
- tdb->tdb2.direct_access--;
- ecode = TDB_SUCCESS;
- }
-
- return ecode;
-}
-
-static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len,
- bool write_mode)
-{
- enum TDB_ERROR ecode;
-
- if (unlikely(!tdb->file->map_ptr))
- return NULL;
-
- ecode = tdb_oob(tdb, off, len, false);
- if (unlikely(ecode != TDB_SUCCESS))
- return TDB_ERR_PTR(ecode);
- return (char *)tdb->file->map_ptr + off;
-}
-
-void tdb_inc_seqnum(struct tdb_context *tdb)
-{
- tdb_off_t seq;
-
- if (tdb->flags & TDB_VERSION1) {
- tdb1_increment_seqnum_nonblock(tdb);
- return;
- }
-
- if (likely(!(tdb->flags & TDB_CONVERT))) {
- int64_t *direct;
-
- direct = tdb->tdb2.io->direct(tdb,
- offsetof(struct tdb_header,
- seqnum),
- sizeof(*direct), true);
- if (likely(direct)) {
- /* Don't let it go negative, even briefly */
- if (unlikely((*direct) + 1) < 0)
- *direct = 0;
- (*direct)++;
- return;
- }
- }
-
- seq = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
- if (!TDB_OFF_IS_ERR(seq)) {
- seq++;
- if (unlikely((int64_t)seq < 0))
- seq = 0;
- tdb_write_off(tdb, offsetof(struct tdb_header, seqnum), seq);
- }
-}
-
-static const struct tdb_methods io_methods = {
- tdb_read,
- tdb_write,
- tdb_oob,
- tdb_expand_file,
- tdb_direct,
-};
-
-/*
- initialise the default methods table
-*/
-void tdb_io_init(struct tdb_context *tdb)
-{
- tdb->tdb2.io = &io_methods;
-}
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