source: vendor/3.5.0/source3/printing/printing_db.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial 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 3 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, see <http://www.gnu.org/licenses/>.
20*/
21
22#include "includes.h"
23#include "printing.h"
24
25static struct tdb_print_db *print_db_head;
26
27/****************************************************************************
28 Function to find or create the printer specific job tdb given a printername.
29 Limits the number of tdb's open to MAX_PRINT_DBS_OPEN.
30****************************************************************************/
31
32struct tdb_print_db *get_print_db_byname(const char *printername)
33{
34 struct tdb_print_db *p = NULL, *last_entry = NULL;
35 int num_open = 0;
36 char *printdb_path = NULL;
37 bool done_become_root = False;
38
39 SMB_ASSERT(printername != NULL);
40
41 for (p = print_db_head, last_entry = print_db_head; p; p = p->next) {
42 /* Ensure the list terminates... JRA. */
43 SMB_ASSERT(p->next != print_db_head);
44
45 if (p->tdb && strequal(p->printer_name, printername)) {
46 DLIST_PROMOTE(print_db_head, p);
47 p->ref_count++;
48 return p;
49 }
50 num_open++;
51 last_entry = p;
52 }
53
54 /* Not found. */
55 if (num_open >= MAX_PRINT_DBS_OPEN) {
56 /* Try and recycle the last entry. */
57 if (print_db_head && last_entry) {
58 DLIST_PROMOTE(print_db_head, last_entry);
59 }
60
61 for (p = print_db_head; p; p = p->next) {
62 if (p->ref_count)
63 continue;
64 if (p->tdb) {
65 if (tdb_close(print_db_head->tdb)) {
66 DEBUG(0,("get_print_db: Failed to close tdb for printer %s\n",
67 print_db_head->printer_name ));
68 return NULL;
69 }
70 }
71 p->tdb = NULL;
72 p->ref_count = 0;
73 memset(p->printer_name, '\0', sizeof(p->printer_name));
74 break;
75 }
76 if (p && print_db_head) {
77 DLIST_PROMOTE(print_db_head, p);
78 p = print_db_head;
79 }
80 }
81
82 if (!p) {
83 /* Create one. */
84 p = SMB_MALLOC_P(struct tdb_print_db);
85 if (!p) {
86 DEBUG(0,("get_print_db: malloc fail !\n"));
87 return NULL;
88 }
89 ZERO_STRUCTP(p);
90 DLIST_ADD(print_db_head, p);
91 }
92
93 if (asprintf(&printdb_path, "%s%s.tdb",
94 cache_path("printing/"),
95 printername) < 0) {
96 DLIST_REMOVE(print_db_head, p);
97 SAFE_FREE(p);
98 return NULL;
99 }
100
101 if (geteuid() != 0) {
102 become_root();
103 done_become_root = True;
104 }
105
106 p->tdb = tdb_open_log(printdb_path, 5000, TDB_DEFAULT, O_RDWR|O_CREAT,
107 0600);
108
109 if (done_become_root)
110 unbecome_root();
111
112 if (!p->tdb) {
113 DEBUG(0,("get_print_db: Failed to open printer backend database %s.\n",
114 printdb_path ));
115 DLIST_REMOVE(print_db_head, p);
116 SAFE_FREE(printdb_path);
117 SAFE_FREE(p);
118 return NULL;
119 }
120 SAFE_FREE(printdb_path);
121 fstrcpy(p->printer_name, printername);
122 p->ref_count++;
123 return p;
124}
125
126/***************************************************************************
127 Remove a reference count.
128****************************************************************************/
129
130void release_print_db( struct tdb_print_db *pdb)
131{
132 pdb->ref_count--;
133 SMB_ASSERT(pdb->ref_count >= 0);
134}
135
136/***************************************************************************
137 Close all open print db entries.
138****************************************************************************/
139
140void close_all_print_db(void)
141{
142 struct tdb_print_db *p = NULL, *next_p = NULL;
143
144 for (p = print_db_head; p; p = next_p) {
145 next_p = p->next;
146
147 if (p->tdb)
148 tdb_close(p->tdb);
149 DLIST_REMOVE(print_db_head, p);
150 ZERO_STRUCTP(p);
151 SAFE_FREE(p);
152 }
153}
154
155
156/****************************************************************************
157 Fetch and clean the pid_t record list for all pids interested in notify
158 messages. data needs freeing on exit.
159****************************************************************************/
160
161TDB_DATA get_printer_notify_pid_list(TDB_CONTEXT *tdb, const char *printer_name, bool cleanlist)
162{
163 TDB_DATA data;
164 size_t i;
165
166 ZERO_STRUCT(data);
167
168 data = tdb_fetch_bystring( tdb, NOTIFY_PID_LIST_KEY );
169
170 if (!data.dptr) {
171 ZERO_STRUCT(data);
172 return data;
173 }
174
175 if (data.dsize % 8) {
176 DEBUG(0,("get_printer_notify_pid_list: Size of record for printer %s not a multiple of 8 !\n", printer_name ));
177 tdb_delete_bystring(tdb, NOTIFY_PID_LIST_KEY );
178 SAFE_FREE(data.dptr);
179 ZERO_STRUCT(data);
180 return data;
181 }
182
183 if (!cleanlist)
184 return data;
185
186 /*
187 * Weed out all dead entries.
188 */
189
190 for( i = 0; i < data.dsize; i += 8) {
191 pid_t pid = (pid_t)IVAL(data.dptr, i);
192
193 if (pid == sys_getpid())
194 continue;
195
196 /* Entry is dead if process doesn't exist or refcount is zero. */
197
198 while ((i < data.dsize) && ((IVAL(data.dptr, i + 4) == 0) || !process_exists_by_pid(pid))) {
199
200 /* Refcount == zero is a logic error and should never happen. */
201 if (IVAL(data.dptr, i + 4) == 0) {
202 DEBUG(0,("get_printer_notify_pid_list: Refcount == 0 for pid = %u printer %s !\n",
203 (unsigned int)pid, printer_name ));
204 }
205
206 if (data.dsize - i > 8)
207 memmove( &data.dptr[i], &data.dptr[i+8], data.dsize - i - 8);
208 data.dsize -= 8;
209 }
210 }
211
212 return data;
213}
214
215
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