source: branches/samba-3.5.x/source3/smbd/dnsregister.c

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

Samba 3.5.0: Initial import
File size: 5.1 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 DNS-SD registration
4 Copyright (C) Rishi Srivatsavai 2007
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
18*/
19
20#include <includes.h>
21
22/* Uses DNS service discovery (libdns_sd) to
23 * register the SMB service. SMB service is registered
24 * on ".local" domain via Multicast DNS & any
25 * other unicast DNS domains available.
26 *
27 * Users use the smbclient -B (Browse) option to
28 * browse for advertised SMB services.
29 */
30
31#define DNS_REG_RETRY_INTERVAL (5*60) /* in seconds */
32
33#ifdef WITH_DNSSD_SUPPORT
34
35#include <dns_sd.h>
36
37struct dns_reg_state {
38 struct tevent_context *event_ctx;
39 uint16_t port;
40 DNSServiceRef srv_ref;
41 struct tevent_timer *te;
42 int fd;
43 struct tevent_fd *fde;
44};
45
46static int dns_reg_state_destructor(struct dns_reg_state *dns_state)
47{
48 if (dns_state->srv_ref != NULL) {
49 /* Close connection to the mDNS daemon */
50 DNSServiceRefDeallocate(dns_state->srv_ref);
51 dns_state->srv_ref = NULL;
52 }
53
54 /* Clear event handler */
55 TALLOC_FREE(dns_state->te);
56 TALLOC_FREE(dns_state->fde);
57 dns_state->fd = -1;
58
59 return 0;
60}
61
62static void dns_register_smbd_retry(struct tevent_context *ctx,
63 struct tevent_timer *te,
64 struct timeval now,
65 void *private_data);
66static void dns_register_smbd_fde_handler(struct tevent_context *ev,
67 struct tevent_fd *fde,
68 uint16_t flags,
69 void *private_data);
70
71static bool dns_register_smbd_schedule(struct dns_reg_state *dns_state,
72 struct timeval tval)
73{
74 dns_reg_state_destructor(dns_state);
75
76 dns_state->te = tevent_add_timer(dns_state->event_ctx,
77 dns_state,
78 tval,
79 dns_register_smbd_retry,
80 dns_state);
81 if (!dns_state->te) {
82 return false;
83 }
84
85 return true;
86}
87
88static void dns_register_smbd_retry(struct tevent_context *ctx,
89 struct tevent_timer *te,
90 struct timeval now,
91 void *private_data)
92{
93 struct dns_reg_state *dns_state = talloc_get_type_abort(private_data,
94 struct dns_reg_state);
95 DNSServiceErrorType err;
96
97 dns_reg_state_destructor(dns_state);
98
99 DEBUG(6, ("registering _smb._tcp service on port %d\n",
100 dns_state->port));
101
102 /* Register service with DNS. Connects with the mDNS
103 * daemon running on the local system to perform DNS
104 * service registration.
105 */
106 err = DNSServiceRegister(&dns_state->srv_ref, 0 /* flags */,
107 kDNSServiceInterfaceIndexAny,
108 NULL /* service name */,
109 "_smb._tcp" /* service type */,
110 NULL /* domain */,
111 "" /* SRV target host name */,
112 htons(dns_state->port),
113 0 /* TXT record len */,
114 NULL /* TXT record data */,
115 NULL /* callback func */,
116 NULL /* callback context */);
117
118 if (err != kDNSServiceErr_NoError) {
119 /* Failed to register service. Schedule a re-try attempt.
120 */
121 DEBUG(3, ("unable to register with mDNS (err %d)\n", err));
122 goto retry;
123 }
124
125 dns_state->fd = DNSServiceRefSockFD(dns_state->srv_ref);
126 if (dns_state->fd == -1) {
127 goto retry;
128 }
129
130 dns_state->fde = tevent_add_fd(dns_state->event_ctx,
131 dns_state,
132 dns_state->fd,
133 TEVENT_FD_READ,
134 dns_register_smbd_fde_handler,
135 dns_state);
136 if (!dns_state->fde) {
137 goto retry;
138 }
139
140 return;
141 retry:
142 dns_register_smbd_schedule(dns_state,
143 timeval_current_ofs(DNS_REG_RETRY_INTERVAL, 0));
144}
145
146/* Processes reply from mDNS daemon. Returns true if a reply was received */
147static void dns_register_smbd_fde_handler(struct tevent_context *ev,
148 struct tevent_fd *fde,
149 uint16_t flags,
150 void *private_data)
151{
152 struct dns_reg_state *dns_state = talloc_get_type_abort(private_data,
153 struct dns_reg_state);
154 DNSServiceErrorType err;
155
156 err = DNSServiceProcessResult(dns_state->srv_ref);
157 if (err != kDNSServiceErr_NoError) {
158 DEBUG(3, ("failed to process mDNS result (err %d), re-trying\n",
159 err));
160 goto retry;
161 }
162
163 talloc_free(dns_state);
164 return;
165
166 retry:
167 dns_register_smbd_schedule(dns_state,
168 timeval_current_ofs(DNS_REG_RETRY_INTERVAL, 0));
169}
170
171bool smbd_setup_mdns_registration(struct tevent_context *ev,
172 TALLOC_CTX *mem_ctx,
173 uint16_t port)
174{
175 struct dns_reg_state *dns_state;
176
177 dns_state = talloc_zero(mem_ctx, struct dns_reg_state);
178 if (dns_state == NULL) {
179 return false;
180 }
181 dns_state->event_ctx = ev;
182 dns_state->port = port;
183 dns_state->fd = -1;
184
185 talloc_set_destructor(dns_state, dns_reg_state_destructor);
186
187 return dns_register_smbd_schedule(dns_state, timeval_zero());
188}
189
190#else /* WITH_DNSSD_SUPPORT */
191
192bool smbd_setup_mdns_registration(struct tevent_context *ev,
193 TALLOC_CTX *mem_ctx,
194 uint16_t port)
195{
196 return true;
197}
198
199#endif /* WITH_DNSSD_SUPPORT */
Note: See TracBrowser for help on using the repository browser.