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

Last change on this file was 988, checked in by Silvan Scherrer, 9 years ago

Samba Server: update vendor to version 4.4.3
File size: 5.7 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 "system/passwd.h" /* uid_wrapper */
24#include "system/filesys.h"
25#include "printing.h"
26#include "util_tdb.h"
27
28static struct tdb_print_db *print_db_head;
29
30/****************************************************************************
31 Function to find or create the printer specific job tdb given a printername.
32 Limits the number of tdb's open to MAX_PRINT_DBS_OPEN.
33****************************************************************************/
34
35struct tdb_print_db *get_print_db_byname(const char *printername)
36{
37 struct tdb_print_db *p = NULL, *last_entry = NULL;
38 int num_open = 0;
39 char *printdb_path = NULL;
40 bool done_become_root = False;
41 char *print_cache_path;
42 int ret;
43
44 SMB_ASSERT(printername != NULL);
45
46 for (p = print_db_head, last_entry = print_db_head; p; p = p->next) {
47 /* Ensure the list terminates... JRA. */
48 SMB_ASSERT(p->next != print_db_head);
49
50 if (p->tdb && strequal(p->printer_name, printername)) {
51 DLIST_PROMOTE(print_db_head, p);
52 p->ref_count++;
53 return p;
54 }
55 num_open++;
56 last_entry = p;
57 }
58
59 /* Not found. */
60 if (num_open >= MAX_PRINT_DBS_OPEN) {
61 /* Try and recycle the last entry. */
62 if (print_db_head && last_entry) {
63 DLIST_PROMOTE(print_db_head, last_entry);
64 }
65
66 for (p = print_db_head; p; p = p->next) {
67 if (p->ref_count)
68 continue;
69 if (p->tdb) {
70 if (tdb_close(p->tdb)) {
71 DEBUG(0,("get_print_db: Failed to close tdb for printer %s\n",
72 p->printer_name ));
73 return NULL;
74 }
75 }
76 p->tdb = NULL;
77 p->ref_count = 0;
78 memset(p->printer_name, '\0', sizeof(p->printer_name));
79 break;
80 }
81 if (p && print_db_head) {
82 DLIST_PROMOTE(print_db_head, p);
83 p = print_db_head;
84 }
85 }
86
87 if (!p) {
88 /* Create one. */
89 p = SMB_MALLOC_P(struct tdb_print_db);
90 if (!p) {
91 DEBUG(0,("get_print_db: malloc fail !\n"));
92 return NULL;
93 }
94 ZERO_STRUCTP(p);
95 DLIST_ADD(print_db_head, p);
96 }
97
98 print_cache_path = cache_path("printing/");
99 if (print_cache_path == NULL) {
100 DLIST_REMOVE(print_db_head, p);
101 SAFE_FREE(p);
102 return NULL;
103 }
104 ret = asprintf(&printdb_path, "%s%s.tdb",
105 print_cache_path, printername);
106 TALLOC_FREE(print_cache_path);
107 if (ret < 0) {
108 DLIST_REMOVE(print_db_head, p);
109 SAFE_FREE(p);
110 return NULL;
111 }
112
113 if (geteuid() != sec_initial_uid()) {
114 become_root();
115 done_become_root = True;
116 }
117
118 p->tdb = tdb_open_log(printdb_path, 5000, TDB_DEFAULT, O_RDWR|O_CREAT,
119 0600);
120
121 if (done_become_root)
122 unbecome_root();
123
124 if (!p->tdb) {
125 DEBUG(0,("get_print_db: Failed to open printer backend database %s.\n",
126 printdb_path ));
127 DLIST_REMOVE(print_db_head, p);
128 SAFE_FREE(printdb_path);
129 SAFE_FREE(p);
130 return NULL;
131 }
132 SAFE_FREE(printdb_path);
133 fstrcpy(p->printer_name, printername);
134 p->ref_count++;
135 return p;
136}
137
138/***************************************************************************
139 Remove a reference count.
140****************************************************************************/
141
142void release_print_db( struct tdb_print_db *pdb)
143{
144 pdb->ref_count--;
145 SMB_ASSERT(pdb->ref_count >= 0);
146}
147
148/***************************************************************************
149 Close all open print db entries.
150****************************************************************************/
151
152void close_all_print_db(void)
153{
154 struct tdb_print_db *p = NULL, *next_p = NULL;
155
156 for (p = print_db_head; p; p = next_p) {
157 next_p = p->next;
158
159 if (p->tdb)
160 tdb_close(p->tdb);
161 DLIST_REMOVE(print_db_head, p);
162 ZERO_STRUCTP(p);
163 SAFE_FREE(p);
164 }
165}
166
167
168/****************************************************************************
169 Fetch and clean the pid_t record list for all pids interested in notify
170 messages. data needs freeing on exit.
171****************************************************************************/
172
173TDB_DATA get_printer_notify_pid_list(struct tdb_context *tdb, const char *printer_name, bool cleanlist)
174{
175 TDB_DATA data;
176 size_t i;
177
178 ZERO_STRUCT(data);
179
180 data = tdb_fetch_bystring( tdb, NOTIFY_PID_LIST_KEY );
181
182 if (!data.dptr) {
183 ZERO_STRUCT(data);
184 return data;
185 }
186
187 if (data.dsize % 8) {
188 DEBUG(0,("get_printer_notify_pid_list: Size of record for printer %s not a multiple of 8 !\n", printer_name ));
189 tdb_delete_bystring(tdb, NOTIFY_PID_LIST_KEY );
190 SAFE_FREE(data.dptr);
191 ZERO_STRUCT(data);
192 return data;
193 }
194
195 if (!cleanlist)
196 return data;
197
198 /*
199 * Weed out all dead entries.
200 */
201
202 for( i = 0; i < data.dsize; i += 8) {
203 pid_t pid = (pid_t)IVAL(data.dptr, i);
204
205 if (pid == getpid())
206 continue;
207
208 /* Entry is dead if process doesn't exist or refcount is zero. */
209
210 while ((i < data.dsize) && ((IVAL(data.dptr, i + 4) == 0) || !process_exists_by_pid(pid))) {
211
212 /* Refcount == zero is a logic error and should never happen. */
213 if (IVAL(data.dptr, i + 4) == 0) {
214 DEBUG(0,("get_printer_notify_pid_list: Refcount == 0 for pid = %u printer %s !\n",
215 (unsigned int)pid, printer_name ));
216 }
217
218 if (data.dsize - i > 8)
219 memmove( &data.dptr[i], &data.dptr[i+8], data.dsize - i - 8);
220 data.dsize -= 8;
221 }
222 }
223
224 return data;
225}
226
227
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