1 /* snd_utils.c
2 **
3 ** Copyright (c) 2019, The Linux Foundation. All rights reserved.
4 **
5 ** Redistribution and use in source and binary forms, with or without
6 ** modification, are permitted provided that the following conditions are
7 ** met:
8 ** * Redistributions of source code must retain the above copyright
9 ** notice, this list of conditions and the following disclaimer.
10 ** * Redistributions in binary form must reproduce the above
11 ** copyright notice, this list of conditions and the following
12 ** disclaimer in the documentation and/or other materials provided
13 ** with the distribution.
14 ** * Neither the name of The Linux Foundation nor the names of its
15 ** contributors may be used to endorse or promote products derived
16 ** from this software without specific prior written permission.
17 **
18 ** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
19 ** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20 ** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
21 ** ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
22 ** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 ** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 ** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
25 ** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26 ** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
27 ** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
28 ** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 **/
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <errno.h>
34 #include "snd_utils.h"
35
36 #define SND_DLSYM(h, p, s, err) \
37 do { \
38 err = 0; \
39 p = dlsym(h, s); \
40 if (!p) \
41 err = -ENODEV; \
42 } while(0)
43
snd_utils_get_int(struct snd_node * node,const char * prop,int * val)44 int snd_utils_get_int(struct snd_node *node, const char *prop, int *val)
45 {
46 if (!node || !node->card_node || !node->dev_node)
47 return SND_NODE_TYPE_HW;
48
49 return node->get_int(node->dev_node, prop, val);
50 }
51
snd_utils_get_str(struct snd_node * node,const char * prop,char ** val)52 int snd_utils_get_str(struct snd_node *node, const char *prop, char **val)
53 {
54 if (!node || !node->card_node || !node->dev_node)
55 return SND_NODE_TYPE_HW;
56
57 return node->get_str(node->dev_node, prop, val);
58 }
59
snd_utils_put_dev_node(struct snd_node * node)60 void snd_utils_put_dev_node(struct snd_node *node)
61 {
62 if (!node)
63 return;
64
65 if (node->card_node)
66 node->put_card(node->card_node);
67
68 if (node->dl_hdl)
69 dlclose(node->dl_hdl);
70
71 free(node);
72 }
73
snd_utils_get_node_type(struct snd_node * node)74 enum snd_node_type snd_utils_get_node_type(struct snd_node *node)
75 {
76 int val = SND_NODE_TYPE_HW;
77
78 if (!node || !node->card_node || !node->dev_node)
79 return SND_NODE_TYPE_HW;
80
81 node->get_int(node->dev_node, "type", &val);
82
83 return val;
84 };
85
86
snd_utils_resolve_symbols(struct snd_node * node)87 static int snd_utils_resolve_symbols(struct snd_node *node)
88 {
89 void *dl = node->dl_hdl;
90 int err;
91
92 SND_DLSYM(dl, node->get_card, "snd_card_def_get_card", err);
93 if (err)
94 goto done;
95 SND_DLSYM(dl, node->put_card, "snd_card_def_put_card", err);
96 if (err)
97 goto done;
98 SND_DLSYM(dl, node->get_node, "snd_card_def_get_node", err);
99 if (err)
100 goto done;
101 SND_DLSYM(dl, node->get_int, "snd_card_def_get_int", err);
102 if (err)
103 goto done;
104 SND_DLSYM(dl, node->get_str, "snd_card_def_get_str", err);
105
106 done:
107 return err;
108 }
109
snd_utils_get_dev_node(unsigned int card,unsigned int device,int dev_type)110 struct snd_node *snd_utils_get_dev_node(unsigned int card,
111 unsigned int device, int dev_type)
112 {
113 struct snd_node *node;
114 int rc = 0;
115
116 node = calloc(1, sizeof(*node));
117 if (!node)
118 return NULL;
119
120 node->dl_hdl = dlopen("libsndcardparser.so", RTLD_NOW);
121 if (!node->dl_hdl) {
122 goto err_dl_open;
123 }
124
125 rc = snd_utils_resolve_symbols(node);
126 if (rc < 0)
127 goto err_resolve_symbols;
128
129 node->card_node = node->get_card(card);
130 if (!node->card_node)
131 goto err_resolve_symbols;
132
133 node->dev_node = node->get_node(node->card_node,
134 device, dev_type);
135 if (!node->dev_node)
136 goto err_get_node;
137
138 return node;
139
140 err_get_node:
141 node->put_card(node->card_node);
142
143 err_resolve_symbols:
144 dlclose(node->dl_hdl);
145
146 err_dl_open:
147 free(node);
148 return NULL;
149 }
150