summaryrefslogtreecommitdiff
path: root/backend/escl/escl_devices.c
blob: 92e064b97037f3788849d2ba607423a17e65c21f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/* sane - Scanner Access Now Easy.

   Copyright (C) 2019 Touboul Nathane
   Copyright (C) 2019 Thierry HUCHARD <thierry@ordissimo.com>

   This file is part of the SANE package.

   SANE 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 3 of the License, or (at your
   option) any later version.

   SANE 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 sane; see the file COPYING.
   If not, see <https://www.gnu.org/licenses/>.

   This file implements a SANE backend for eSCL scanners.  */

#define DEBUG_DECLARE_ONLY
#include "../include/sane/config.h"

#include "escl.h"

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <avahi-client/lookup.h>
#include <avahi-common/error.h>
#include <avahi-common/simple-watch.h>

#include "../include/sane/sanei.h"

static AvahiSimplePoll *simple_poll = NULL;
static int count_finish = 0;

/**
 * \fn static void resolve_callback(AvahiServiceResolver *r, AVAHI_GCC_UNUSED
 * AvahiIfIndex interface, AVAHI_GCC_UNUSED AvahiProtocol protocol,
 * AvahiResolverEvent event, const char *name,
 *                            const char *type, const char *domain, const char *host_name,
 *                            const AvahiAddress *address, uint16_t port,
 *                            AvahiStringList *txt, AvahiLookupResultFlags flags,
 *                            void *userdata)
 * \brief Callback function that will check if the selected scanner follows the escl
 *  protocol or not.
 */
static void
resolve_callback(AvahiServiceResolver *r, AVAHI_GCC_UNUSED AvahiIfIndex interface,
                            AVAHI_GCC_UNUSED AvahiProtocol protocol,
                            AvahiResolverEvent event, const char *name,
                            const char __sane_unused__ *type,
                            const char __sane_unused__ *domain,
                            const char __sane_unused__ *host_name,
                            const AvahiAddress *address, uint16_t port, AvahiStringList *txt,
                            AvahiLookupResultFlags __sane_unused__ flags,
                            void __sane_unused__ *userdata)
{
    char a[AVAHI_ADDRESS_STR_MAX], *t;
    const char *is;
    const char *uuid;
    AvahiStringList   *s;
    assert(r);
    switch (event) {
    case AVAHI_RESOLVER_FAILURE:
        break;
    case AVAHI_RESOLVER_FOUND:
        avahi_address_snprint(a, sizeof(a), address);
        t = avahi_string_list_to_string(txt);
        if (strstr(t, "\"rs=eSCL\"") || strstr(t, "\"rs=/eSCL\"")) {
	    char ip_add[PATH_MAX] = {0};
	    s = avahi_string_list_find(txt, "is");
	    if (s && s->size > 3)
	       is = (const char*)s->text + 3;
	    else
	       is = (const char*)NULL;
	    s = avahi_string_list_find(txt, "uuid");
	    if (s && s->size > 5)
	       uuid = (const char*)s->text + 5;
	    else
	       uuid = (const char*)NULL;
            DBG (10, "resolve_callback [%s]\n", a);
            if (strstr(a, "127.0.0.1") != NULL) {
               snprintf(ip_add, sizeof(ip_add), "%s", "localhost");
               DBG (10,"resolve_callback fix redirect [localhost]\n");
            }
            else
               snprintf(ip_add, sizeof(ip_add), "%s", a);
            escl_device_add(port, name, ip_add, is, uuid, (char*)type);
        }
    }
}

/**
 * \fn static void browse_callback(AvahiServiceBrowser *b, AvahiIfIndex interface,
 * AvahiProtocol protocol, AvahiBrowserEvent event, const char *name,
 * const char *type, const char *domain,
 *                           AVAHI_GCC_UNUSED AvahiLookupResultFlags flags, void* userdata)
 * \brief Callback function that will browse tanks to 'avahi' the scanners
 * connected in network.
 */
static void
browse_callback(AvahiServiceBrowser *b, AvahiIfIndex interface,
                            AvahiProtocol protocol, AvahiBrowserEvent event,
                            const char *name, const char *type,
                            const char *domain,
                            AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
                            void* userdata)
{
    AvahiClient *c = userdata;
    assert(b);
    switch (event) {
    case AVAHI_BROWSER_FAILURE:
        avahi_simple_poll_quit(simple_poll);
        return;
    case AVAHI_BROWSER_NEW:
        if (!(avahi_service_resolver_new(c, interface, protocol, name,
                                                               type, domain,
                                                               AVAHI_PROTO_UNSPEC, 0,
                                                               resolve_callback, c)))
            break;
    case AVAHI_BROWSER_REMOVE:
        break;
    case AVAHI_BROWSER_ALL_FOR_NOW:
    case AVAHI_BROWSER_CACHE_EXHAUSTED:
        if (event != AVAHI_BROWSER_CACHE_EXHAUSTED)
           {
		count_finish++;
		if (count_finish == 2)
            		avahi_simple_poll_quit(simple_poll);
	   }
        break;
    }
}

/**
 * \fn static void client_callback(AvahiClient *c, AvahiClientState state,
 * AVAHI_GCC_UNUSED void *userdata)
 * \brief Callback Function that quit if it doesn't find a connected scanner,
 * possible thanks the "Hello Protocol".
 *        --> Waiting for a answer by the scanner to continue the avahi process.
 */
static void
client_callback(AvahiClient *c, AvahiClientState state,
                         AVAHI_GCC_UNUSED void *userdata)
{
    assert(c);
    if (state == AVAHI_CLIENT_FAILURE)
        avahi_simple_poll_quit(simple_poll);
}

/**
 * \fn ESCL_Device *escl_devices(SANE_Status *status)
 * \brief Function that calls all the avahi functions and then, recovers the
 * connected eSCL devices.
 *        This function is called in the 'sane_get_devices' function.
 *
 * \return NULL (the eSCL devices found)
 */
ESCL_Device *
escl_devices(SANE_Status *status)
{
    AvahiClient *client = NULL;
    AvahiServiceBrowser *sb = NULL;
    int error;

    count_finish = 0;

    *status = SANE_STATUS_GOOD;
    if (!(simple_poll = avahi_simple_poll_new())) {
        DBG( 1, "Failed to create simple poll object.\n");
        *status = SANE_STATUS_INVAL;
        goto fail;
    }
    client = avahi_client_new(avahi_simple_poll_get(simple_poll), 0,
                                               client_callback, NULL, &error);
    if (!client) {
        DBG( 1, "Failed to create client: %s\n", avahi_strerror(error));
        *status = SANE_STATUS_INVAL;
        goto fail;
    }
    if (!(sb = avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
                                                                   AVAHI_PROTO_UNSPEC, "_uscan._tcp",
                                                                   NULL, 0, browse_callback, client))) {
        DBG( 1, "Failed to create service browser: %s\n",
                              avahi_strerror(avahi_client_errno(client)));
        *status = SANE_STATUS_INVAL;
        goto fail;
    }
    if (!(sb = avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
                                                                   AVAHI_PROTO_UNSPEC,
                                                                   "_uscans._tcp", NULL, 0,
                                                                   browse_callback, client))) {
        DBG( 1, "Failed to create service browser: %s\n",
                                avahi_strerror(avahi_client_errno(client)));
        *status = SANE_STATUS_INVAL;
        goto fail;
    }
    avahi_simple_poll_loop(simple_poll);
fail:
    if (sb)
        avahi_service_browser_free(sb);
    if (client)
        avahi_client_free(client);
    if (simple_poll)
        avahi_simple_poll_free(simple_poll);
    return (NULL);
}