From e945511aae52c0bc50007ffc703241c7da1db372 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Fri, 11 May 2012 22:11:42 +0200 Subject: move the dbwrap library to the top level Autobuild-User: Michael Adam Autobuild-Date: Mon May 14 04:04:55 CEST 2012 on sn-devel-104 --- lib/dbwrap/dbwrap_file.c | 418 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 418 insertions(+) create mode 100644 lib/dbwrap/dbwrap_file.c (limited to 'lib/dbwrap/dbwrap_file.c') diff --git a/lib/dbwrap/dbwrap_file.c b/lib/dbwrap/dbwrap_file.c new file mode 100644 index 0000000000..e0fd4ebc73 --- /dev/null +++ b/lib/dbwrap/dbwrap_file.c @@ -0,0 +1,418 @@ +/* + Unix SMB/CIFS implementation. + Database interface using a file per record + Copyright (C) Volker Lendecke 2005 + + This program 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 of the License, or + (at your option) any later version. + + This program 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 this program. If not, see . +*/ + +#include "includes.h" +#include "dbwrap/dbwrap.h" +#include "dbwrap/dbwrap_file.h" +#include "dbwrap/dbwrap_private.h" +#include "lib/tdb_wrap/tdb_wrap.h" + +struct db_file_ctx { + const char *dirname; + + /* We only support one locked record at a time -- everything else + * would lead to a potential deadlock anyway! */ + struct db_record *locked_record; +}; + +struct db_locked_file { + int fd; + uint8_t hash; + const char *name; + const char *path; + struct db_file_ctx *parent; +}; + +/* Copy from statcache.c... */ + +static uint32_t fsh(const uint8_t *p, int len) +{ + uint32_t n = 0; + int i; + for (i=0; iparent != NULL) { + data->parent->locked_record = NULL; + } + + if (close(data->fd) != 0) { + DEBUG(3, ("close failed: %s\n", strerror(errno))); + return -1; + } + + return 0; +} + +static NTSTATUS db_file_store(struct db_record *rec, TDB_DATA data, int flag); +static NTSTATUS db_file_delete(struct db_record *rec); + +static struct db_record *db_file_fetch_locked(struct db_context *db, + TALLOC_CTX *mem_ctx, + TDB_DATA key) +{ + struct db_file_ctx *ctx = talloc_get_type_abort(db->private_data, + struct db_file_ctx); + struct db_record *result; + struct db_locked_file *file; + struct flock fl; + SMB_STRUCT_STAT statbuf; + int ret; + + SMB_ASSERT(ctx->locked_record == NULL); + + again: + if (!(result = talloc(mem_ctx, struct db_record))) { + DEBUG(0, ("talloc failed\n")); + return NULL; + } + + if (!(file = talloc(result, struct db_locked_file))) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + result->private_data = file; + result->store = db_file_store; + result->delete_rec = db_file_delete; + + result->key.dsize = key.dsize; + result->key.dptr = (uint8_t *)talloc_memdup(result, key.dptr, + key.dsize); + if (result->key.dptr == NULL) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + /* Cut to 8 bits */ + file->hash = fsh(key.dptr, key.dsize); + file->name = hex_encode_talloc(file, (unsigned char *)key.dptr, key.dsize); + if (file->name == NULL) { + DEBUG(0, ("hex_encode failed\n")); + TALLOC_FREE(result); + return NULL; + } + + file->path = talloc_asprintf(file, "%s/%2.2X/%s", ctx->dirname, + file->hash, file->name); + if (file->path == NULL) { + DEBUG(0, ("talloc_asprintf failed\n")); + TALLOC_FREE(result); + return NULL; + } + + become_root(); + file->fd = open(file->path, O_RDWR|O_CREAT, 0644); + unbecome_root(); + + if (file->fd < 0) { + DEBUG(3, ("Could not open/create %s: %s\n", + file->path, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + talloc_set_destructor(file, db_locked_file_destr); + + fl.l_type = F_WRLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 1; + fl.l_pid = 0; + + do { + ret = fcntl(file->fd, F_SETLKW, &fl); + } while ((ret == -1) && (errno == EINTR)); + + if (ret == -1) { + DEBUG(3, ("Could not get lock on %s: %s\n", + file->path, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + if (sys_fstat(file->fd, &statbuf, false) != 0) { + DEBUG(3, ("Could not fstat %s: %s\n", + file->path, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + if (statbuf.st_ex_nlink == 0) { + /* Someone has deleted it under the lock, retry */ + TALLOC_FREE(result); + goto again; + } + + result->value.dsize = 0; + result->value.dptr = NULL; + + if (statbuf.st_ex_size != 0) { + NTSTATUS status; + + result->value.dsize = statbuf.st_ex_size; + result->value.dptr = talloc_array(result, uint8_t, + statbuf.st_ex_size); + if (result->value.dptr == NULL) { + DEBUG(1, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + status = read_data(file->fd, (char *)result->value.dptr, + result->value.dsize); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(3, ("read_data failed: %s\n", + nt_errstr(status))); + TALLOC_FREE(result); + return NULL; + } + } + + ctx->locked_record = result; + file->parent = (struct db_file_ctx *)talloc_reference(file, ctx); + + return result; +} + +static NTSTATUS db_file_store_root(int fd, TDB_DATA data) +{ + if (lseek(fd, 0, SEEK_SET) != 0) { + DEBUG(0, ("lseek failed: %s\n", strerror(errno))); + return map_nt_error_from_unix(errno); + } + + if (write_data(fd, (char *)data.dptr, data.dsize) != data.dsize) { + DEBUG(3, ("write_data failed: %s\n", strerror(errno))); + return map_nt_error_from_unix(errno); + } + + if (ftruncate(fd, data.dsize) != 0) { + DEBUG(3, ("ftruncate failed: %s\n", strerror(errno))); + return map_nt_error_from_unix(errno); + } + + return NT_STATUS_OK; +} + +static NTSTATUS db_file_store(struct db_record *rec, TDB_DATA data, int flag) +{ + struct db_locked_file *file = + talloc_get_type_abort(rec->private_data, + struct db_locked_file); + NTSTATUS status; + + become_root(); + status = db_file_store_root(file->fd, data); + unbecome_root(); + + return status; +} + +static NTSTATUS db_file_delete(struct db_record *rec) +{ + struct db_locked_file *file = + talloc_get_type_abort(rec->private_data, + struct db_locked_file); + int res; + + become_root(); + res = unlink(file->path); + unbecome_root(); + + if (res == -1) { + DEBUG(3, ("unlink(%s) failed: %s\n", file->path, + strerror(errno))); + return map_nt_error_from_unix(errno); + } + + return NT_STATUS_OK; +} + +static int db_file_traverse(struct db_context *db, + int (*fn)(struct db_record *rec, + void *private_data), + void *private_data) +{ + struct db_file_ctx *ctx = talloc_get_type_abort(db->private_data, + struct db_file_ctx); + TALLOC_CTX *mem_ctx = talloc_init("traversal %s\n", ctx->dirname); + + int i; + int count = 0; + + for (i=0; i<256; i++) { + const char *dirname = talloc_asprintf(mem_ctx, "%s/%2.2X", + ctx->dirname, i); + DIR *dir; + struct dirent *dirent; + + if (dirname == NULL) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(mem_ctx); + return -1; + } + + dir = opendir(dirname); + if (dir == NULL) { + DEBUG(3, ("Could not open dir %s: %s\n", dirname, + strerror(errno))); + TALLOC_FREE(mem_ctx); + return -1; + } + + while ((dirent = readdir(dir)) != NULL) { + DATA_BLOB keyblob; + TDB_DATA key; + struct db_record *rec; + + if ((dirent->d_name[0] == '.') && + ((dirent->d_name[1] == '\0') || + ((dirent->d_name[1] == '.') && + (dirent->d_name[2] == '\0')))) { + continue; + } + + keyblob = strhex_to_data_blob(mem_ctx, dirent->d_name); + if (keyblob.data == NULL) { + DEBUG(5, ("strhex_to_data_blob failed\n")); + continue; + } + + key.dptr = keyblob.data; + key.dsize = keyblob.length; + + if ((ctx->locked_record != NULL) && + (key.dsize == ctx->locked_record->key.dsize) && + (memcmp(key.dptr, ctx->locked_record->key.dptr, + key.dsize) == 0)) { + count += 1; + if (fn(ctx->locked_record, + private_data) != 0) { + TALLOC_FREE(mem_ctx); + closedir(dir); + return count; + } + } + + rec = db_file_fetch_locked(db, mem_ctx, key); + if (rec == NULL) { + /* Someone might have deleted it */ + continue; + } + + if (rec->value.dptr == NULL) { + TALLOC_FREE(rec); + continue; + } + + count += 1; + + if (fn(rec, private_data) != 0) { + TALLOC_FREE(mem_ctx); + closedir(dir); + return count; + } + TALLOC_FREE(rec); + } + + closedir(dir); + } + + TALLOC_FREE(mem_ctx); + return count; +} + +struct db_context *db_open_file(TALLOC_CTX *mem_ctx, + struct messaging_context *msg_ctx, + const char *name, + int hash_size, int tdb_flags, + int open_flags, mode_t mode) +{ + struct db_context *result = NULL; + struct db_file_ctx *ctx; + + if (!(result = talloc_zero(mem_ctx, struct db_context))) { + DEBUG(0, ("talloc failed\n")); + return NULL; + } + + if (!(ctx = talloc(result, struct db_file_ctx))) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + result->private_data = ctx; + result->fetch_locked = db_file_fetch_locked; + result->try_fetch_locked = NULL; + result->traverse = db_file_traverse; + result->traverse_read = db_file_traverse; + result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0); + + ctx->locked_record = NULL; + if (!(ctx->dirname = talloc_strdup(ctx, name))) { + DEBUG(0, ("talloc failed\n")); + TALLOC_FREE(result); + return NULL; + } + + if (open_flags & O_CREAT) { + int ret, i; + + mode |= (mode & S_IRUSR) ? S_IXUSR : 0; + mode |= (mode & S_IRGRP) ? S_IXGRP : 0; + mode |= (mode & S_IROTH) ? S_IXOTH : 0; + + ret = mkdir(name, mode); + if ((ret != 0) && (errno != EEXIST)) { + DEBUG(5, ("mkdir(%s,%o) failed: %s\n", name, mode, + strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + + for (i=0; i<256; i++) { + char *path; + path = talloc_asprintf(result, "%s/%2.2X", name, i); + if (path == NULL) { + DEBUG(0, ("asprintf failed\n")); + TALLOC_FREE(result); + return NULL; + } + ret = mkdir(path, mode); + if ((ret != 0) && (errno != EEXIST)) { + DEBUG(5, ("mkdir(%s,%o) failed: %s\n", path, + mode, strerror(errno))); + TALLOC_FREE(result); + return NULL; + } + TALLOC_FREE(path); + } + } + + return result; +} -- cgit