1 /*
2 * lws-minimal-raw-file
3 *
4 * Written in 2010-2019 by Andy Green <andy@warmcat.com>
5 *
6 * This file is made available under the Creative Commons CC0 1.0
7 * Universal Public Domain Dedication.
8 *
9 * This demonstrates adopting a file descriptor into the lws event
10 * loop.
11 */
12
13 #include <libwebsockets.h>
14 #include <string.h>
15 #include <signal.h>
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <fcntl.h>
19
20 struct raw_vhd {
21 // lws_sock_file_fd_type u;
22 int filefd;
23 };
24
25 static char filepath[256];
26
27 static int
callback_raw_test(struct lws * wsi,enum lws_callback_reasons reason,void * user,void * in,size_t len)28 callback_raw_test(struct lws *wsi, enum lws_callback_reasons reason,
29 void *user, void *in, size_t len)
30 {
31 struct raw_vhd *vhd = (struct raw_vhd *)lws_protocol_vh_priv_get(
32 lws_get_vhost(wsi), lws_get_protocol(wsi));
33 lws_sock_file_fd_type u;
34 uint8_t buf[1024];
35 int n;
36
37 switch (reason) {
38 case LWS_CALLBACK_PROTOCOL_INIT:
39 vhd = lws_protocol_vh_priv_zalloc(lws_get_vhost(wsi),
40 lws_get_protocol(wsi), sizeof(struct raw_vhd));
41 vhd->filefd = lws_open(filepath, O_RDWR);
42 if (vhd->filefd == -1) {
43 lwsl_err("Unable to open %s\n", filepath);
44
45 return 1;
46 }
47 u.filefd = (lws_filefd_type)(long long)vhd->filefd;
48 if (!lws_adopt_descriptor_vhost(lws_get_vhost(wsi),
49 LWS_ADOPT_RAW_FILE_DESC, u,
50 "raw-test", NULL)) {
51 lwsl_err("Failed to adopt fifo descriptor\n");
52 close(vhd->filefd);
53 vhd->filefd = -1;
54
55 return 1;
56 }
57 break;
58
59 case LWS_CALLBACK_PROTOCOL_DESTROY:
60 if (vhd && vhd->filefd != -1)
61 close(vhd->filefd);
62 break;
63
64 /* callbacks related to raw file descriptor */
65
66 case LWS_CALLBACK_RAW_ADOPT_FILE:
67 lwsl_notice("LWS_CALLBACK_RAW_ADOPT_FILE\n");
68 break;
69
70 case LWS_CALLBACK_RAW_RX_FILE:
71 lwsl_notice("LWS_CALLBACK_RAW_RX_FILE\n");
72 n = (int)read(vhd->filefd, buf, sizeof(buf));
73 if (n < 0) {
74 lwsl_err("Reading from %s failed\n", filepath);
75
76 return 1;
77 }
78 lwsl_hexdump_level(LLL_NOTICE, buf, (unsigned int)n);
79 break;
80
81 case LWS_CALLBACK_RAW_CLOSE_FILE:
82 lwsl_notice("LWS_CALLBACK_RAW_CLOSE_FILE\n");
83 break;
84
85 case LWS_CALLBACK_RAW_WRITEABLE_FILE:
86 lwsl_notice("LWS_CALLBACK_RAW_WRITEABLE_FILE\n");
87 /*
88 * you can call lws_callback_on_writable() on a raw file wsi as
89 * usual, and then write directly into the raw filefd here.
90 */
91 break;
92
93 default:
94 break;
95 }
96
97 return 0;
98 }
99
100 static struct lws_protocols protocols[] = {
101 { "raw-test", callback_raw_test, 0, 0, 0, NULL, 0 },
102 LWS_PROTOCOL_LIST_TERM
103 };
104
105 static int interrupted;
106
sigint_handler(int sig)107 void sigint_handler(int sig)
108 {
109 interrupted = 1;
110 }
111
main(int argc,const char ** argv)112 int main(int argc, const char **argv)
113 {
114 struct lws_context_creation_info info;
115 struct lws_context *context;
116 const char *p;
117 int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
118 /* for LLL_ verbosity above NOTICE to be built into lws,
119 * lws must have been configured and built with
120 * -DCMAKE_BUILD_TYPE=DEBUG instead of =RELEASE */
121 /* | LLL_INFO */ /* | LLL_PARSER */ /* | LLL_HEADER */
122 /* | LLL_EXT */ /* | LLL_CLIENT */ /* | LLL_LATENCY */
123 /* | LLL_DEBUG */;
124
125 signal(SIGINT, sigint_handler);
126
127 if ((p = lws_cmdline_option(argc, argv, "-d")))
128 logs = atoi(p);
129
130 lws_set_log_level(logs, NULL);
131 lwsl_user("LWS minimal raw file\n");
132 if (argc < 2) {
133 lwsl_user("Usage: %s <file to monitor> "
134 " eg, /dev/ttyUSB0 or /dev/input/event0 or "
135 "/proc/self/fd/0\n", argv[0]);
136
137 return 1;
138 }
139
140 signal(SIGINT, sigint_handler);
141
142 memset(&info, 0, sizeof info); /* otherwise uninitialized garbage */
143 info.port = CONTEXT_PORT_NO_LISTEN_SERVER; /* no listen socket for demo */
144 info.protocols = protocols;
145
146 lws_strncpy(filepath, argv[1], sizeof(filepath));
147
148 context = lws_create_context(&info);
149 if (!context) {
150 lwsl_err("lws init failed\n");
151 return 1;
152 }
153
154 while (n >= 0 && !interrupted)
155 n = lws_service(context, 0);
156
157 lws_context_destroy(context);
158
159 return 0;
160 }
161