xref: /openbmc/linux/samples/connector/ucon.c (revision 1a59d1b8)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * 	ucon.c
4  *
5  * Copyright (c) 2004+ Evgeniy Polyakov <zbr@ioremap.net>
6  */
7 
8 #include <asm/types.h>
9 
10 #include <sys/types.h>
11 #include <sys/socket.h>
12 #include <sys/poll.h>
13 
14 #include <linux/netlink.h>
15 #include <linux/rtnetlink.h>
16 
17 #include <arpa/inet.h>
18 
19 #include <stdbool.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 #include <string.h>
24 #include <errno.h>
25 #include <time.h>
26 #include <getopt.h>
27 
28 #include <linux/connector.h>
29 
30 #define DEBUG
31 #define NETLINK_CONNECTOR 	11
32 
33 /* Hopefully your userspace connector.h matches this kernel */
34 #define CN_TEST_IDX		CN_NETLINK_USERS + 3
35 #define CN_TEST_VAL		0x456
36 
37 #ifdef DEBUG
38 #define ulog(f, a...) fprintf(stdout, f, ##a)
39 #else
40 #define ulog(f, a...) do {} while (0)
41 #endif
42 
43 static int need_exit;
44 static __u32 seq;
45 
netlink_send(int s,struct cn_msg * msg)46 static int netlink_send(int s, struct cn_msg *msg)
47 {
48 	struct nlmsghdr *nlh;
49 	unsigned int size;
50 	int err;
51 	char buf[128];
52 	struct cn_msg *m;
53 
54 	size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
55 
56 	nlh = (struct nlmsghdr *)buf;
57 	nlh->nlmsg_seq = seq++;
58 	nlh->nlmsg_pid = getpid();
59 	nlh->nlmsg_type = NLMSG_DONE;
60 	nlh->nlmsg_len = size;
61 	nlh->nlmsg_flags = 0;
62 
63 	m = NLMSG_DATA(nlh);
64 #if 0
65 	ulog("%s: [%08x.%08x] len=%u, seq=%u, ack=%u.\n",
66 	       __func__, msg->id.idx, msg->id.val, msg->len, msg->seq, msg->ack);
67 #endif
68 	memcpy(m, msg, sizeof(*m) + msg->len);
69 
70 	err = send(s, nlh, size, 0);
71 	if (err == -1)
72 		ulog("Failed to send: %s [%d].\n",
73 			strerror(errno), errno);
74 
75 	return err;
76 }
77 
usage(void)78 static void usage(void)
79 {
80 	printf(
81 		"Usage: ucon [options] [output file]\n"
82 		"\n"
83 		"\t-h\tthis help screen\n"
84 		"\t-s\tsend buffers to the test module\n"
85 		"\n"
86 		"The default behavior of ucon is to subscribe to the test module\n"
87 		"and wait for state messages.  Any ones received are dumped to the\n"
88 		"specified output file (or stdout).  The test module is assumed to\n"
89 		"have an id of {%u.%u}\n"
90 		"\n"
91 		"If you get no output, then verify the cn_test module id matches\n"
92 		"the expected id above.\n"
93 		, CN_TEST_IDX, CN_TEST_VAL
94 	);
95 }
96 
main(int argc,char * argv[])97 int main(int argc, char *argv[])
98 {
99 	int s;
100 	char buf[1024];
101 	int len;
102 	struct nlmsghdr *reply;
103 	struct sockaddr_nl l_local;
104 	struct cn_msg *data;
105 	FILE *out;
106 	time_t tm;
107 	struct pollfd pfd;
108 	bool send_msgs = false;
109 
110 	while ((s = getopt(argc, argv, "hs")) != -1) {
111 		switch (s) {
112 		case 's':
113 			send_msgs = true;
114 			break;
115 
116 		case 'h':
117 			usage();
118 			return 0;
119 
120 		default:
121 			/* getopt() outputs an error for us */
122 			usage();
123 			return 1;
124 		}
125 	}
126 
127 	if (argc != optind) {
128 		out = fopen(argv[optind], "a+");
129 		if (!out) {
130 			ulog("Unable to open %s for writing: %s\n",
131 				argv[1], strerror(errno));
132 			out = stdout;
133 		}
134 	} else
135 		out = stdout;
136 
137 	memset(buf, 0, sizeof(buf));
138 
139 	s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
140 	if (s == -1) {
141 		perror("socket");
142 		return -1;
143 	}
144 
145 	l_local.nl_family = AF_NETLINK;
146 	l_local.nl_groups = -1; /* bitmask of requested groups */
147 	l_local.nl_pid = 0;
148 
149 	ulog("subscribing to %u.%u\n", CN_TEST_IDX, CN_TEST_VAL);
150 
151 	if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
152 		perror("bind");
153 		close(s);
154 		return -1;
155 	}
156 
157 #if 0
158 	{
159 		int on = 0x57; /* Additional group number */
160 		setsockopt(s, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &on, sizeof(on));
161 	}
162 #endif
163 	if (send_msgs) {
164 		int i, j;
165 
166 		memset(buf, 0, sizeof(buf));
167 
168 		data = (struct cn_msg *)buf;
169 
170 		data->id.idx = CN_TEST_IDX;
171 		data->id.val = CN_TEST_VAL;
172 		data->seq = seq++;
173 		data->ack = 0;
174 		data->len = 0;
175 
176 		for (j=0; j<10; ++j) {
177 			for (i=0; i<1000; ++i) {
178 				len = netlink_send(s, data);
179 			}
180 
181 			ulog("%d messages have been sent to %08x.%08x.\n", i, data->id.idx, data->id.val);
182 		}
183 
184 		return 0;
185 	}
186 
187 
188 	pfd.fd = s;
189 
190 	while (!need_exit) {
191 		pfd.events = POLLIN;
192 		pfd.revents = 0;
193 		switch (poll(&pfd, 1, -1)) {
194 			case 0:
195 				need_exit = 1;
196 				break;
197 			case -1:
198 				if (errno != EINTR) {
199 					need_exit = 1;
200 					break;
201 				}
202 				continue;
203 		}
204 		if (need_exit)
205 			break;
206 
207 		memset(buf, 0, sizeof(buf));
208 		len = recv(s, buf, sizeof(buf), 0);
209 		if (len == -1) {
210 			perror("recv buf");
211 			close(s);
212 			return -1;
213 		}
214 		reply = (struct nlmsghdr *)buf;
215 
216 		switch (reply->nlmsg_type) {
217 		case NLMSG_ERROR:
218 			fprintf(out, "Error message received.\n");
219 			fflush(out);
220 			break;
221 		case NLMSG_DONE:
222 			data = (struct cn_msg *)NLMSG_DATA(reply);
223 
224 			time(&tm);
225 			fprintf(out, "%.24s : [%x.%x] [%08u.%08u].\n",
226 				ctime(&tm), data->id.idx, data->id.val, data->seq, data->ack);
227 			fflush(out);
228 			break;
229 		default:
230 			break;
231 		}
232 	}
233 
234 	close(s);
235 	return 0;
236 }
237