source: branches/samba-3.0/source/printing/printing_db.c

Last change on this file was 1, checked in by Paul Smedley, 18 years ago

Initial code import
File size: 5.4 KB
Line 
1/*
2 Unix SMB/Netbios implementation.
3 Version 3.0
4 printing backend routines
5 Copyright (C) Andrew Tridgell 1992-2000
6 Copyright (C) Jeremy Allison 2002
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21*/
22
23#include "includes.h"
24#include "printing.h"
25
26static struct tdb_print_db *print_db_head;
27
28/****************************************************************************
29 Function to find or create the printer specific job tdb given a printername.
30 Limits the number of tdb's open to MAX_PRINT_DBS_OPEN.
31****************************************************************************/
32
33struct tdb_print_db *get_print_db_byname(const char *printername)
34{
35 struct tdb_print_db *p = NULL, *last_entry = NULL;
36 int num_open = 0;
37 pstring printdb_path;
38 BOOL done_become_root = False;
39
40 SMB_ASSERT(printername != NULL);
41
42 for (p = print_db_head, last_entry = print_db_head; p; p = p->next) {
43 /* Ensure the list terminates... JRA. */
44 SMB_ASSERT(p->next != print_db_head);
45
46 if (p->tdb && strequal(p->printer_name, printername)) {
47 DLIST_PROMOTE(print_db_head, p);
48 p->ref_count++;
49 return p;
50 }
51 num_open++;
52 last_entry = p;
53 }
54
55 /* Not found. */
56 if (num_open >= MAX_PRINT_DBS_OPEN) {
57 /* Try and recycle the last entry. */
58 if (print_db_head && last_entry) {
59 DLIST_PROMOTE(print_db_head, last_entry);
60 }
61
62 for (p = print_db_head; p; p = p->next) {
63 if (p->ref_count)
64 continue;
65 if (p->tdb) {
66 if (tdb_close(print_db_head->tdb)) {
67 DEBUG(0,("get_print_db: Failed to close tdb for printer %s\n",
68 print_db_head->printer_name ));
69 return NULL;
70 }
71 }
72 p->tdb = NULL;
73 p->ref_count = 0;
74 memset(p->printer_name, '\0', sizeof(p->printer_name));
75 break;
76 }
77 if (p && print_db_head) {
78 DLIST_PROMOTE(print_db_head, p);
79 p = print_db_head;
80 }
81 }
82
83 if (!p) {
84 /* Create one. */
85 p = SMB_MALLOC_P(struct tdb_print_db);
86 if (!p) {
87 DEBUG(0,("get_print_db: malloc fail !\n"));
88 return NULL;
89 }
90 ZERO_STRUCTP(p);
91 DLIST_ADD(print_db_head, p);
92 }
93
94 pstrcpy(printdb_path, lock_path("printing/"));
95 pstrcat(printdb_path, printername);
96 pstrcat(printdb_path, ".tdb");
97
98 if (geteuid() != 0) {
99 become_root();
100 done_become_root = True;
101 }
102
103 p->tdb = tdb_open_log(printdb_path, 5000, TDB_DEFAULT, O_RDWR|O_CREAT,
104 0600);
105
106 if (done_become_root)
107 unbecome_root();
108
109 if (!p->tdb) {
110 DEBUG(0,("get_print_db: Failed to open printer backend database %s.\n",
111 printdb_path ));
112 DLIST_REMOVE(print_db_head, p);
113 SAFE_FREE(p);
114 return NULL;
115 }
116 fstrcpy(p->printer_name, printername);
117 p->ref_count++;
118 return p;
119}
120
121/***************************************************************************
122 Remove a reference count.
123****************************************************************************/
124
125void release_print_db( struct tdb_print_db *pdb)
126{
127 pdb->ref_count--;
128 SMB_ASSERT(pdb->ref_count >= 0);
129}
130
131/***************************************************************************
132 Close all open print db entries.
133****************************************************************************/
134
135void close_all_print_db(void)
136{
137 struct tdb_print_db *p = NULL, *next_p = NULL;
138
139 for (p = print_db_head; p; p = next_p) {
140 next_p = p->next;
141
142 if (p->tdb)
143 tdb_close(p->tdb);
144 DLIST_REMOVE(print_db_head, p);
145 ZERO_STRUCTP(p);
146 SAFE_FREE(p);
147 }
148}
149
150
151/****************************************************************************
152 Fetch and clean the pid_t record list for all pids interested in notify
153 messages. data needs freeing on exit.
154****************************************************************************/
155
156TDB_DATA get_printer_notify_pid_list(TDB_CONTEXT *tdb, const char *printer_name, BOOL cleanlist)
157{
158 TDB_DATA data;
159 size_t i;
160
161 ZERO_STRUCT(data);
162
163 data = tdb_fetch_bystring( tdb, NOTIFY_PID_LIST_KEY );
164
165 if (!data.dptr) {
166 ZERO_STRUCT(data);
167 return data;
168 }
169
170 if (data.dsize % 8) {
171 DEBUG(0,("get_printer_notify_pid_list: Size of record for printer %s not a multiple of 8 !\n", printer_name ));
172 tdb_delete_bystring(tdb, NOTIFY_PID_LIST_KEY );
173 SAFE_FREE(data.dptr);
174 ZERO_STRUCT(data);
175 return data;
176 }
177
178 if (!cleanlist)
179 return data;
180
181 /*
182 * Weed out all dead entries.
183 */
184
185 for( i = 0; i < data.dsize; i += 8) {
186 pid_t pid = (pid_t)IVAL(data.dptr, i);
187
188 if (pid == sys_getpid())
189 continue;
190
191 /* Entry is dead if process doesn't exist or refcount is zero. */
192
193 while ((i < data.dsize) && ((IVAL(data.dptr, i + 4) == 0) || !process_exists_by_pid(pid))) {
194
195 /* Refcount == zero is a logic error and should never happen. */
196 if (IVAL(data.dptr, i + 4) == 0) {
197 DEBUG(0,("get_printer_notify_pid_list: Refcount == 0 for pid = %u printer %s !\n",
198 (unsigned int)pid, printer_name ));
199 }
200
201 if (data.dsize - i > 8)
202 memmove( &data.dptr[i], &data.dptr[i+8], data.dsize - i - 8);
203 data.dsize -= 8;
204 }
205 }
206
207 return data;
208}
209
210
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