/* 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 <http://www.gnu.org/licenses/>. */ #include "includes.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 hash; const char *name; const char *path; struct db_file_ctx *parent; }; /* Copy from statcache.c... */ static uint32 fsh(const uint8 *p, int len) { uint32 n = 0; int i; for (i=0; i<len; i++) { n = ((n << 5) + n) ^ (uint32)(p[i]); } return n; } static int db_locked_file_destr(struct db_locked_file *data) { if (data->parent != 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; ssize_t nread; int ret; SMB_ASSERT(ctx->locked_record == NULL); again: if (!(result = TALLOC_P(mem_ctx, struct db_record))) { DEBUG(0, ("talloc failed\n")); return NULL; } if (!(file = TALLOC_P(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 *)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) != 0) { DEBUG(3, ("Could not fstat %s: %s\n", file->path, strerror(errno))); TALLOC_FREE(result); return NULL; } if (statbuf.st_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_size != 0) { result->value.dsize = statbuf.st_size; result->value.dptr = TALLOC_ARRAY(result, uint8, statbuf.st_size); if (result->value.dptr == NULL) { DEBUG(1, ("talloc failed\n")); TALLOC_FREE(result); return NULL; } nread = read_data(file->fd, (char *)result->value.dptr, result->value.dsize); if (nread != result->value.dsize) { DEBUG(3, ("read_data failed: %s\n", strerror(errno))); 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 (sys_lseek(fd, 0, SEEK_SET) != 0) { DEBUG(0, ("sys_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 (sys_ftruncate(fd, data.dsize) != 0) { DEBUG(3, ("sys_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_P(mem_ctx, struct db_context))) { DEBUG(0, ("talloc failed\n")); return NULL; } if (!(ctx = TALLOC_P(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->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; }