[print notify fixes from APP_HEAD]

 * fixing change notify on print server handle
 * adding change notify support into smbcontrol for sending comment
   changes, etc...

All part of CR 1159/1160
(This used to be commit 256d8c27cdc6f802f3bfba44593b07014f6ae10a)

1 files changed, 204 insertions, 0 deletions

diff --git a/source3/printing/printing_db.c b/source3/printing/printing_db.c
new file mode 100644
index 0000000000..ec33daea1a
--- /dev/null
+++ b/source3/printing/printing_db.c
@@ -0,0 +1,204 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 3.0
+   printing backend routines
+   Copyright (C) Andrew Tridgell 1992-2000
+   Copyright (C) Jeremy Allison 2002
+   
+   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.
+*/
+
+#include "printing.h"
+
+static struct tdb_print_db *print_db_head;
+
+/****************************************************************************
+  Function to find or create the printer specific job tdb given a printername.
+  Limits the number of tdb's open to MAX_PRINT_DBS_OPEN.
+****************************************************************************/
+
+struct tdb_print_db *get_print_db_byname(const char *printername)
+{
+	struct tdb_print_db *p = NULL, *last_entry = NULL;
+	int num_open = 0;
+	pstring printdb_path;
+	BOOL done_become_root = False;
+
+	for (p = print_db_head, last_entry = print_db_head; p; p = p->next) {
+		/* Ensure the list terminates... JRA. */
+		SMB_ASSERT(p->next != print_db_head);
+
+		if (p->tdb && strequal(p->printer_name, printername)) {
+			DLIST_PROMOTE(print_db_head, p);
+			p->ref_count++;
+			return p;
+		}
+		num_open++;
+		last_entry = p;
+	}
+
+	/* Not found. */
+	if (num_open >= MAX_PRINT_DBS_OPEN) {
+		/* Try and recycle the last entry. */
+		DLIST_PROMOTE(print_db_head, last_entry);
+
+		for (p = print_db_head; p; p = p->next) {
+			if (p->ref_count)
+				continue;
+			if (p->tdb) {
+				if (tdb_close(print_db_head->tdb)) {
+					DEBUG(0,("get_print_db: Failed to close tdb for printer %s\n",
+								print_db_head->printer_name ));
+					return NULL;
+				}
+			}
+			p->tdb = NULL;
+			p->ref_count = 0;
+			memset(p->printer_name, '\0', sizeof(p->printer_name));
+			break;
+		}
+		if (p) {
+			DLIST_PROMOTE(print_db_head, p);
+			p = print_db_head;
+		}
+	}
+       
+	if (!p)	{
+		/* Create one. */
+		p = (struct tdb_print_db *)malloc(sizeof(struct tdb_print_db));
+		if (!p) {
+			DEBUG(0,("get_print_db: malloc fail !\n"));
+			return NULL;
+		}
+		ZERO_STRUCTP(p);
+		DLIST_ADD(print_db_head, p);
+	}
+
+	pstrcpy(printdb_path, lock_path("printing/"));
+	pstrcat(printdb_path, printername);
+	pstrcat(printdb_path, ".tdb");
+
+	if (geteuid() != 0) {
+		become_root();
+		done_become_root = True;
+	}
+
+	p->tdb = tdb_open_log(printdb_path, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
+
+	if (done_become_root)
+		unbecome_root();
+
+	if (!p->tdb) {
+		DEBUG(0,("get_print_db: Failed to open printer backend database %s.\n",
+					printdb_path ));
+		DLIST_REMOVE(print_db_head, p);
+		SAFE_FREE(p);
+		return NULL;
+	}
+	fstrcpy(p->printer_name, printername);
+	p->ref_count++;
+	return p;
+}
+
+/***************************************************************************
+ Remove a reference count.
+****************************************************************************/
+
+void release_print_db( struct tdb_print_db *pdb)
+{
+	pdb->ref_count--;
+	SMB_ASSERT(pdb->ref_count >= 0);
+}
+
+/***************************************************************************
+ Close all open print db entries.
+****************************************************************************/
+
+void close_all_print_db(void)
+{
+	struct tdb_print_db *p = NULL, *next_p = NULL;
+
+	for (p = print_db_head; p; p = next_p) {
+		next_p = p->next;
+
+		if (p->tdb)
+			tdb_close(p->tdb);
+		DLIST_REMOVE(print_db_head, p);
+		ZERO_STRUCTP(p);
+		SAFE_FREE(p);
+	}
+}
+
+
+/****************************************************************************
+ Fetch and clean the pid_t record list for all pids interested in notify
+ messages. data needs freeing on exit.
+****************************************************************************/
+
+TDB_DATA get_printer_notify_pid_list(TDB_CONTEXT *tdb, const char *printer_name, BOOL cleanlist)
+{
+	TDB_DATA data;
+	size_t i;
+
+	ZERO_STRUCT(data);
+
+	data = tdb_fetch_by_string( tdb, NOTIFY_PID_LIST_KEY );
+
+	if (!data.dptr) {
+		ZERO_STRUCT(data);
+		return data;
+	}
+
+	if (data.dsize % 8) {
+		DEBUG(0,("get_printer_notify_pid_list: Size of record for printer %s not a multiple of 8 !\n", printer_name ));
+		tdb_delete_by_string(tdb, NOTIFY_PID_LIST_KEY );
+		SAFE_FREE(data.dptr);
+		ZERO_STRUCT(data);
+		return data;
+	}
+
+	if (!cleanlist)
+		return data;
+
+	/*
+	 * Weed out all dead entries.
+	 */
+
+	for( i = 0; i < data.dsize; i += 8) {
+		pid_t pid = (pid_t)IVAL(data.dptr, i);
+
+		if (pid == sys_getpid())
+			continue;
+
+		/* Entry is dead if process doesn't exist or refcount is zero. */
+
+		while ((i < data.dsize) && ((IVAL(data.dptr, i + 4) == 0) || !process_exists(pid))) {
+
+			/* Refcount == zero is a logic error and should never happen. */
+			if (IVAL(data.dptr, i + 4) == 0) {
+				DEBUG(0,("get_printer_notify_pid_list: Refcount == 0 for pid = %u printer %s !\n",
+							(unsigned int)pid, printer_name ));
+			}
+
+			if (data.dsize - i > 8)
+				memmove( &data.dptr[i], &data.dptr[i+8], data.dsize - i - 8);
+			data.dsize -= 8;
+		}
+	}
+
+	return data;
+}
+
+