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
20struct raw_vhd {
21//	lws_sock_file_fd_type u;
22	int filefd;
23};
24
25static char filepath[256];
26
27static int
28callback_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
100static struct lws_protocols protocols[] = {
101	{ "raw-test", callback_raw_test, 0, 0, 0, NULL, 0 },
102	LWS_PROTOCOL_LIST_TERM
103};
104
105static int interrupted;
106
107void sigint_handler(int sig)
108{
109	interrupted = 1;
110}
111
112int 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