/* Unix SMB/CIFS implementation. Locking functions Copyright (C) Andrew Tridgell 1992-2000 Copyright (C) Jeremy Allison 1992-2000 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 2 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, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. Revision History: 12 aug 96: Erik.Devriendt@te6.siemens.be added support for shared memory implementation of share mode locking May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode locking to deal with multiple share modes per open file. September 1997. Jeremy Allison (jallison@whistle.com). Added oplock support. rewrtten completely to use new tdb code. Tridge, Dec '99 Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000. */ #include "includes.h" uint16 global_smbpid; /* the locking database handle */ static TDB_CONTEXT *tdb; /**************************************************************************** Debugging aid :-). ****************************************************************************/ static const char *lock_type_name(enum brl_type lock_type) { return (lock_type == READ_LOCK) ? "READ" : "WRITE"; } /**************************************************************************** Utility function called to see if a file region is locked. If check_self is True, then checks on our own fd with the same locking context are still made. If check_self is False, then checks are not made on our own fd with the same locking context are not made. ****************************************************************************/ BOOL is_locked(files_struct *fsp,connection_struct *conn, SMB_BIG_UINT count,SMB_BIG_UINT offset, enum brl_type lock_type, BOOL check_self) { int snum = SNUM(conn); BOOL ret; if (count == 0) return(False); if (!lp_locking(snum) || !lp_strict_locking(snum)) return(False); ret = !brl_locktest(fsp->dev, fsp->inode, fsp->fnum, global_smbpid, sys_getpid(), conn->cnum, offset, count, lock_type, check_self); DEBUG(10,("is_locked: brl start=%.0f len=%.0f %s for file %s\n", (double)offset, (double)count, ret ? "locked" : "unlocked", fsp->fsp_name )); /* * There is no lock held by an SMB daemon, check to * see if there is a POSIX lock from a UNIX or NFS process. */ if(!ret && lp_posix_locking(snum)) { ret = is_posix_locked(fsp, offset, count, lock_type); DEBUG(10,("is_locked: posix start=%.0f len=%.0f %s for file %s\n", (double)offset, (double)count, ret ? "locked" : "unlocked", fsp->fsp_name )); } return ret; } /**************************************************************************** Utility function called by locking requests. ****************************************************************************/ static NTSTATUS do_lock(files_struct *fsp,connection_struct *conn, uint16 lock_pid, SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type) { NTSTATUS status = NT_STATUS_LOCK_NOT_GRANTED; if (!lp_locking(SNUM(conn))) return NT_STATUS_OK; /* NOTE! 0 byte long ranges ARE allowed and should be stored */ DEBUG(10,("do_lock: lock type %s start=%.0f len=%.0f requested for file %s\n", lock_type_name(lock_type), (double)offset, (double)count, fsp->fsp_name )); if (OPEN_FSP(fsp) && fsp->can_lock && (fsp->conn == conn)) { status = brl_lock(fsp->dev, fsp->inode, fsp->fnum, lock_pid, sys_getpid(), conn->cnum, offset, count, lock_type); if (NT_STATUS_IS_OK(status) && lp_posix_locking(SNUM(conn))) { /* * Try and get a POSIX lock on this range. * Note that this is ok if it is a read lock * overlapping on a different fd. JRA. */ if (!set_posix_lock(fsp, offset, count, lock_type)) { status = NT_STATUS_LOCK_NOT_GRANTED; /* * We failed to map - we must now remove the brl * lock entry. */ (void)brl_unlock(fsp->dev, fsp->inode, fsp->fnum, lock_pid, sys_getpid(), conn->cnum, offset, count, False); } } } return status; } /**************************************************************************** Utility function called by locking requests. This is *DISGUSTING*. It also appears to be "What Windows Does" (tm). Andrew, ever wonder why Windows 2000 is so slow on the locking tests...... ? This is the reason. Much though I hate it, we need this. JRA. ****************************************************************************/ NTSTATUS do_lock_spin(files_struct *fsp,connection_struct *conn, uint16 lock_pid, SMB_BIG_UINT count,SMB_BIG_UINT offset,enum brl_type lock_type) { int j, maxj = lp_lock_spin_count(); int sleeptime = lp_lock_sleep_time(); NTSTATUS status, ret; if (maxj <= 0) maxj = 1; ret = NT_STATUS_OK; /* to keep dumb compilers happy */ for (j = 0; j < maxj; j++) { status = do_lock(fsp, conn, lock_pid, count, offset, lock_type); if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED) && !NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) { return status; } /* if we do fail then return the first error code we got */ if (j == 0) { ret = status; } if (sleeptime) sys_usleep(sleeptime); } return ret; } /**************************************************************************** Utility function called by unlocking requests. ****************************************************************************/ NTSTATUS do_unlock(files_struct *fsp,connection_struct *conn, uint16 lock_pid, SMB_BIG_UINT count,SMB_BIG_UINT offset) { BOOL ok = False; if (!lp_locking(SNUM(conn))) return NT_STATUS_OK; if (!OPEN_FSP(fsp) || !fsp->can_lock || (fsp->conn != conn)) { return NT_STATUS_INVALID_HANDLE; } DEBUG(10,("do_unlock: unlock start=%.0f len=%.0f requested for file %s\n", (double)offset, (double)count, fsp->fsp_name )); /* * Remove the existing lock record from the tdb lockdb * before looking at POSIX locks. If this record doesn't * match then don't bother looking to remove POSIX locks. */ ok = brl_unlock(fsp->dev, fsp->inode, fsp->fnum, lock_pid, sys_getpid(), conn->cnum, offset, count, False); if (!ok) { DEBUG(10,("do_unlock: returning ERRlock.\n" )); return NT_STATUS_RANGE_NOT_LOCKED; } if (!lp_posix_locking(SNUM(conn))) return NT_STATUS_OK; (void)release_posix_lock(fsp, offset, count); return NT_STATUS_OK; } /**************************************************************************** Remove any locks on this fd. Called from file_close(). ****************************************************************************/ void locking_close_file(files_struct *fsp) { pid_t pid = sys_getpid(); if (!lp_locking(SNUM(fsp->conn))) return; /* * Just release all the brl locks, no need to release individually. */ brl_close(fsp->dev, fsp->inode, pid, fsp->conn->cnum, fsp->fnum); if(lp_posix_locking(SNUM(fsp->conn))) { /* * Release all the POSIX locks. */ posix_locking_close_file(fsp); } } /**************************************************************************** Initialise the locking functions. ****************************************************************************/ static int open_read_only; BOOL locking_init(int read_only) { brl_init(read_only); if (tdb) return True; tdb = tdb_open_log(lock_path("locking.tdb"), 0, TDB_DEFAULT|(read_only?0x0:TDB_CLEAR_IF_FIRST), read_only?O_RDONLY:O_RDWR|O_CREAT, 0644); if (!tdb) { DEBUG(0,("ERROR: Failed to initialise locking database\n")); return False; } if (!posix_locking_init(read_only)) return False; open_read_only = read_only; return True; } /******************************************************************* Deinitialize the share_mode management. ******************************************************************/ BOOL locking_end(void) { brl_shutdown(open_read_only); if (tdb) { if (tdb_close(tdb) != 0) return False; } return True; } /******************************************************************* Form a static locking key for a dev/inode pair. ******************************************************************/ static TDB_DATA locking_key(SMB_DEV_T dev, SMB_INO_T inode) { static struct locking_key key; TDB_DATA kbuf; memset(&key, '\0', sizeof(key)); key.dev = dev; key.inode = inode; kbuf.dptr = (char *)&key; kbuf.dsize = sizeof(key); return kbuf; } static TDB_DATA locking_key_fsp(files_struct *fsp) { return locking_key(fsp->dev, fsp->inode); } /******************************************************************* Lock a hash bucket entry. ******************************************************************/ BOOL lock_share_entry(connection_struct *conn, SMB_DEV_T dev, SMB_INO_T inode) { return tdb_chainlock(tdb, locking_key(dev, inode)) == 0; } /******************************************************************* Unlock a hash bucket entry. ******************************************************************/ void unlock_share_entry(connection_struct *conn, SMB_DEV_T dev, SMB_INO_T inode) { tdb_chainunlock(tdb, locking_key(dev, inode)); } /******************************************************************* Lock a hash bucket entry. use a fsp for convenience ******************************************************************/ BOOL lock_share_entry_fsp(files_struct *fsp) { return tdb_chainlock(tdb, locking_key(fsp->dev, fsp->inode)) == 0; } /******************************************************************* Unlock a hash bucket entry. ******************************************************************/ void unlock_share_entry_fsp(files_struct *fsp) { tdb_chainunlock(tdb, locking_key(fsp->dev, fsp->inode)); } /******************************************************************* Print out a share mode. ********************************************************************/ static char *share_mode_str(int num, share_mode_entry *e) { static pstring share_str; slprintf(share_str, sizeof(share_str)-1, "share_mode_entry[%d]: \ pid = %u, share_mode = 0x%x, desired_access = 0x%x, port = 0x%x, type= 0x%x, file_id = %lu, dev = 0x%x, inode = %.0f", num, e->pid, e->share_mode, (unsigned int)e->desired_access, e->op_port, e->op_type, e->share_file_id, (unsigned int)e->dev, (double)e->inode ); return share_str; } /******************************************************************* Print out a share mode table. ********************************************************************/ static void print_share_mode_table(struct locking_data *data) { int num_share_modes = data->u.num_share_mode_entries; share_mode_entry *shares = (share_mode_entry *)(data + 1); int i; for (i = 0; i < num_share_modes; i++) { share_mode_entry *entry_p = &shares[i]; DEBUG(10,("print_share_mode_table: %s\n", share_mode_str(i, entry_p) )); } } /******************************************************************* Get all share mode entries for a dev/inode pair. ********************************************************************/ int get_share_modes(connection_struct *conn, SMB_DEV_T dev, SMB_INO_T inode, share_mode_entry **pp_shares) { TDB_DATA dbuf; struct locking_data *data; int num_share_modes; share_mode_entry *shares = NULL; *pp_shares = NULL; dbuf = tdb_fetch(tdb, locking_key(dev, inode)); if (!dbuf.dptr) return 0; data = (struct locking_data *)dbuf.dptr; num_share_modes = data->u.num_share_mode_entries; if(num_share_modes) { int i; int del_count = 0; shares = (share_mode_entry *)memdup(dbuf.dptr + sizeof(*data), num_share_modes * sizeof(share_mode_entry)); if (!shares) { SAFE_FREE(dbuf.dptr); return 0; } /* * Ensure that each entry has a real process attached. */ for (i = 0; i < num_share_modes; ) { share_mode_entry *entry_p = &shares[i]; if (process_exists(entry_p->pid)) { DEBUG(10,("get_share_modes: %s\n", share_mode_str(i, entry_p) )); i++; } else { DEBUG(10,("get_share_modes: deleted %s\n", share_mode_str(i, entry_p) )); memcpy( &shares[i], &shares[i+1], sizeof(share_mode_entry) * (num_share_modes - i - 1)); num_share_modes--; del_count++; } } /* Did we delete any ? If so, re-store in tdb. */ if (del_count) { data->u.num_share_mode_entries = num_share_modes; if (num_share_modes) memcpy(dbuf.dptr + sizeof(*data), shares, num_share_modes * sizeof(share_mode_entry)); /* The record has shrunk a bit */ dbuf.dsize -= del_count * sizeof(share_mode_entry); if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1) { SAFE_FREE(shares); SAFE_FREE(dbuf.dptr); return 0; } } } SAFE_FREE(dbuf.dptr); *pp_shares = shares; return num_share_modes; } /******************************************************************* Fill a share mode entry. ********************************************************************/ static void fill_share_mode(char *p, files_struct *fsp, uint16 port, uint16 op_type) { share_mode_entry *e = (share_mode_entry *)p; void *x = &e->time; /* Needed to force alignment. p may not be aligned.... */ memset(e, '\0', sizeof(share_mode_entry)); e->pid = sys_getpid(); e->share_mode = fsp->share_mode; e->desired_access = fsp->desired_access; e->op_port = port; e->op_type = op_type; memcpy(x, &fsp->open_time, sizeof(struct timeval)); e->share_file_id = fsp->file_id; e->dev = fsp->dev; e->inode = fsp->inode; } /******************************************************************* Check if two share mode entries are identical, ignoring oplock and port info and desired_access. ********************************************************************/ BOOL share_modes_identical( share_mode_entry *e1, share_mode_entry *e2) { #if 1 /* JRA PARANOIA TEST - REMOVE LATER */ if (e1->pid == e2->pid && e1->share_file_id == e2->share_file_id && e1->dev == e2->dev && e1->inode == e2->inode && (e1->share_mode & ~DELETE_ON_CLOSE_FLAG) != (e2->share_mode & ~DELETE_ON_CLOSE_FLAG)) { DEBUG(0,("PANIC: share_modes_identical: share_mode missmatch (e1 = %u, e2 = %u). Logic error.\n", (unsigned int)(e1->share_mode & ~DELETE_ON_CLOSE_FLAG), (unsigned int)(e2->share_mode & ~DELETE_ON_CLOSE_FLAG) )); smb_panic("PANIC: share_modes_identical logic error.\n"); } #endif return (e1->pid == e2->pid && (e1->share_mode & ~DELETE_ON_CLOSE_FLAG) == (e2->share_mode & ~DELETE_ON_CLOSE_FLAG) && e1->dev == e2->dev && e1->inode == e2->inode && e1->share_file_id == e2->share_file_id ); } /******************************************************************* Delete a specific share mode. Return the number of entries left, and a memdup'ed copy of the entry deleted (if required). Ignore if no entry deleted. ********************************************************************/ ssize_t del_share_entry( SMB_DEV_T dev, SMB_INO_T inode, share_mode_entry *entry, share_mode_entry **ppse) { TDB_DATA dbuf; struct locking_data *data; int i, del_count=0; share_mode_entry *shares; ssize_t count = 0; if (ppse) *ppse = NULL; /* read in the existing share modes */ dbuf = tdb_fetch(tdb, locking_key(dev, inode)); if (!dbuf.dptr) return -1; data = (struct locking_data *)dbuf.dptr; shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data)); /* * Find any with this pid and delete it * by overwriting with the rest of the data * from the record. */ DEBUG(10,("del_share_entry: num_share_modes = %d\n", data->u.num_share_mode_entries )); for (i=0;i<data->u.num_share_mode_entries;) { if (share_modes_identical(&shares[i], entry)) { DEBUG(10,("del_share_entry: deleted %s\n", share_mode_str(i, &shares[i]) )); if (ppse) *ppse = memdup(&shares[i], sizeof(*shares)); data->u.num_share_mode_entries--; memmove(&shares[i], &shares[i+1], dbuf.dsize - (sizeof(*data) + (i+1)*sizeof(*shares))); del_count++; DEBUG(10,("del_share_entry: deleting entry %d\n", i )); } else { i++; } } if (del_count) { /* the record may have shrunk a bit */ dbuf.dsize -= del_count * sizeof(*shares); count = (ssize_t)data->u.num_share_mode_entries; /* store it back in the database */ if (data->u.num_share_mode_entries == 0) { if (tdb_delete(tdb, locking_key(dev, inode)) == -1) count = -1; } else { if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1) count = -1; } } DEBUG(10,("del_share_entry: Remaining table.\n")); print_share_mode_table((struct locking_data *)dbuf.dptr); SAFE_FREE(dbuf.dptr); return count; } /******************************************************************* Del the share mode of a file for this process. Return the number of entries left, and a memdup'ed copy of the entry deleted. ********************************************************************/ ssize_t del_share_mode(files_struct *fsp, share_mode_entry **ppse) { share_mode_entry entry; /* * Fake up a share_mode_entry for comparisons. */ fill_share_mode((char *)&entry, fsp, 0, 0); return del_share_entry(fsp->dev, fsp->inode, &entry, ppse); } /******************************************************************* Set the share mode of a file. Return False on fail, True on success. ********************************************************************/ BOOL set_share_mode(files_struct *fsp, uint16 port, uint16 op_type) { TDB_DATA dbuf; struct locking_data *data; char *p=NULL; int size; BOOL ret = True; /* read in the existing share modes if any */ dbuf = tdb_fetch(tdb, locking_key_fsp(fsp)); if (!dbuf.dptr) { size_t offset; /* we'll need to create a new record */ pstring fname; pstrcpy(fname, fsp->conn->connectpath); pstrcat(fname, "/"); pstrcat(fname, fsp->fsp_name); size = sizeof(*data) + sizeof(share_mode_entry) + strlen(fname) + 1; p = (char *)malloc(size); if (!p) return False; data = (struct locking_data *)p; data->u.num_share_mode_entries = 1; DEBUG(10,("set_share_mode: creating entry for file %s. num_share_modes = 1\n", fsp->fsp_name )); offset = sizeof(*data) + sizeof(share_mode_entry); safe_strcpy(p + offset, fname, size - offset - 1); fill_share_mode(p + sizeof(*data), fsp, port, op_type); dbuf.dptr = p; dbuf.dsize = size; if (tdb_store(tdb, locking_key_fsp(fsp), dbuf, TDB_REPLACE) == -1) ret = False; print_share_mode_table((struct locking_data *)p); SAFE_FREE(p); return ret; } /* we're adding to an existing entry - this is a bit fiddly */ data = (struct locking_data *)dbuf.dptr; data->u.num_share_mode_entries++; DEBUG(10,("set_share_mode: adding entry for file %s. new num_share_modes = %d\n", fsp->fsp_name, data->u.num_share_mode_entries )); size = dbuf.dsize + sizeof(share_mode_entry); p = malloc(size); if (!p) { SAFE_FREE(dbuf.dptr); return False; } memcpy(p, dbuf.dptr, sizeof(*data)); fill_share_mode(p + sizeof(*data), fsp, port, op_type); memcpy(p + sizeof(*data) + sizeof(share_mode_entry), dbuf.dptr + sizeof(*data), dbuf.dsize - sizeof(*data)); SAFE_FREE(dbuf.dptr); dbuf.dptr = p; dbuf.dsize = size; if (tdb_store(tdb, locking_key_fsp(fsp), dbuf, TDB_REPLACE) == -1) ret = False; print_share_mode_table((struct locking_data *)p); SAFE_FREE(p); return ret; } /******************************************************************* A generic in-place modification call for share mode entries. ********************************************************************/ static BOOL mod_share_mode( SMB_DEV_T dev, SMB_INO_T inode, share_mode_entry *entry, void (*mod_fn)(share_mode_entry *, SMB_DEV_T, SMB_INO_T, void *), void *param) { TDB_DATA dbuf; struct locking_data *data; int i; share_mode_entry *shares; BOOL need_store=False; BOOL ret = True; /* read in the existing share modes */ dbuf = tdb_fetch(tdb, locking_key(dev, inode)); if (!dbuf.dptr) return False; data = (struct locking_data *)dbuf.dptr; shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data)); /* find any with our pid and call the supplied function */ for (i=0;i<data->u.num_share_mode_entries;i++) { if (share_modes_identical(entry, &shares[i])) { mod_fn(&shares[i], dev, inode, param); need_store=True; } } /* if the mod fn was called then store it back */ if (need_store) { if (data->u.num_share_mode_entries == 0) { if (tdb_delete(tdb, locking_key(dev, inode)) == -1) ret = False; } else { if (tdb_store(tdb, locking_key(dev, inode), dbuf, TDB_REPLACE) == -1) ret = False; } } SAFE_FREE(dbuf.dptr); return ret; } /******************************************************************* Static function that actually does the work for the generic function below. ********************************************************************/ static void remove_share_oplock_fn(share_mode_entry *entry, SMB_DEV_T dev, SMB_INO_T inode, void *param) { DEBUG(10,("remove_share_oplock_fn: removing oplock info for entry dev=%x ino=%.0f\n", (unsigned int)dev, (double)inode )); /* Delete the oplock info. */ entry->op_port = 0; entry->op_type = NO_OPLOCK; } /******************************************************************* Remove an oplock port and mode entry from a share mode. ********************************************************************/ BOOL remove_share_oplock(files_struct *fsp) { share_mode_entry entry; /* * Fake up an entry for comparisons... */ fill_share_mode((char *)&entry, fsp, 0, 0); return mod_share_mode(fsp->dev, fsp->inode, &entry, remove_share_oplock_fn, NULL); } /******************************************************************* Static function that actually does the work for the generic function below. ********************************************************************/ static void downgrade_share_oplock_fn(share_mode_entry *entry, SMB_DEV_T dev, SMB_INO_T inode, void *param) { DEBUG(10,("downgrade_share_oplock_fn: downgrading oplock info for entry dev=%x ino=%.0f\n", (unsigned int)dev, (double)inode )); entry->op_type = LEVEL_II_OPLOCK; } /******************************************************************* Downgrade a oplock type from exclusive to level II. ********************************************************************/ BOOL downgrade_share_oplock(files_struct *fsp) { share_mode_entry entry; /* * Fake up an entry for comparisons... */ fill_share_mode((char *)&entry, fsp, 0, 0); return mod_share_mode(fsp->dev, fsp->inode, &entry, downgrade_share_oplock_fn, NULL); } /******************************************************************* Get/Set the delete on close flag in a set of share modes. Return False on fail, True on success. ********************************************************************/ BOOL modify_delete_flag( SMB_DEV_T dev, SMB_INO_T inode, BOOL delete_on_close) { TDB_DATA dbuf; struct locking_data *data; int i; share_mode_entry *shares; /* read in the existing share modes */ dbuf = tdb_fetch(tdb, locking_key(dev, inode)); if (!dbuf.dptr) return False; data = (struct locking_data *)dbuf.dptr; shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data)); /* Set/Unset the delete on close element. */ for (i=0;i<data->u.num_share_mode_entries;i++,shares++) { shares->share_mode = (delete_on_close ? (shares->share_mode | DELETE_ON_CLOSE_FLAG) : (shares->share_mode & ~DELETE_ON_CLOSE_FLAG) ); } /* store it back */ if (data->u.num_share_mode_entries) { if (tdb_store(tdb, locking_key(dev,inode), dbuf, TDB_REPLACE)==-1) { SAFE_FREE(dbuf.dptr); return False; } } SAFE_FREE(dbuf.dptr); return True; } /**************************************************************************** Traverse the whole database with this function, calling traverse_callback on each share mode ****************************************************************************/ static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void* state) { struct locking_data *data; share_mode_entry *shares; char *name; int i; SHAREMODE_FN(traverse_callback) = (SHAREMODE_FN_CAST())state; data = (struct locking_data *)dbuf.dptr; shares = (share_mode_entry *)(dbuf.dptr + sizeof(*data)); name = dbuf.dptr + sizeof(*data) + data->u.num_share_mode_entries*sizeof(*shares); for (i=0;i<data->u.num_share_mode_entries;i++) { traverse_callback(&shares[i], name); } return 0; } /******************************************************************* Call the specified function on each entry under management by the share mode system. ********************************************************************/ int share_mode_forall(SHAREMODE_FN(fn)) { if (!tdb) return 0; return tdb_traverse(tdb, traverse_fn, (void*)fn); }