summaryrefslogtreecommitdiff
path: root/tools/testing/vsock/control.c
blob: 0066e0324d35c65dcce569d6f73394be075c9dbc (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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
// SPDX-License-Identifier: GPL-2.0-only
/* Control socket for client/server test execution
 *
 * Copyright (C) 2017 Red Hat, Inc.
 *
 * Author: Stefan Hajnoczi <stefanha@redhat.com>
 */

/* The client and server may need to coordinate to avoid race conditions like
 * the client attempting to connect to a socket that the server is not
 * listening on yet.  The control socket offers a communications channel for
 * such coordination tasks.
 *
 * If the client calls control_expectln("LISTENING"), then it will block until
 * the server calls control_writeln("LISTENING").  This provides a simple
 * mechanism for coordinating between the client and the server.
 */

#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>

#include "timeout.h"
#include "control.h"
#include "util.h"

static int control_fd = -1;

/* Open the control socket, either in server or client mode */
void control_init(const char *control_host,
		  const char *control_port,
		  bool server)
{
	struct addrinfo hints = {
		.ai_socktype = SOCK_STREAM,
	};
	struct addrinfo *result = NULL;
	struct addrinfo *ai;
	int ret;

	ret = getaddrinfo(control_host, control_port, &hints, &result);
	if (ret != 0) {
		fprintf(stderr, "%s\n", gai_strerror(ret));
		exit(EXIT_FAILURE);
	}

	for (ai = result; ai; ai = ai->ai_next) {
		int fd;

		fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
		if (fd < 0)
			continue;

		if (!server) {
			if (connect(fd, ai->ai_addr, ai->ai_addrlen) < 0)
				goto next;
			control_fd = fd;
			printf("Control socket connected to %s:%s.\n",
			       control_host, control_port);
			break;
		}

		setsockopt_int_check(fd, SOL_SOCKET, SO_REUSEADDR, 1,
				     "setsockopt SO_REUSEADDR");

		if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0)
			goto next;
		if (listen(fd, 1) < 0)
			goto next;

		printf("Control socket listening on %s:%s\n",
		       control_host, control_port);
		fflush(stdout);

		control_fd = accept(fd, NULL, 0);
		close(fd);

		if (control_fd < 0) {
			perror("accept");
			exit(EXIT_FAILURE);
		}
		printf("Control socket connection accepted...\n");
		break;

next:
		close(fd);
	}

	if (control_fd < 0) {
		fprintf(stderr, "Control socket initialization failed.  Invalid address %s:%s?\n",
			control_host, control_port);
		exit(EXIT_FAILURE);
	}

	freeaddrinfo(result);
}

/* Free resources */
void control_cleanup(void)
{
	close(control_fd);
	control_fd = -1;
}

/* Write a line to the control socket */
void control_writeln(const char *str)
{
	ssize_t len = strlen(str);
	ssize_t ret;

	timeout_begin(TIMEOUT);

	do {
		ret = send(control_fd, str, len, MSG_MORE);
		timeout_check("send");
	} while (ret < 0 && errno == EINTR);

	if (ret != len) {
		perror("send");
		exit(EXIT_FAILURE);
	}

	do {
		ret = send(control_fd, "\n", 1, 0);
		timeout_check("send");
	} while (ret < 0 && errno == EINTR);

	if (ret != 1) {
		perror("send");
		exit(EXIT_FAILURE);
	}

	timeout_end();
}

void control_writeulong(unsigned long value)
{
	char str[32];

	if (snprintf(str, sizeof(str), "%lu", value) >= sizeof(str)) {
		perror("snprintf");
		exit(EXIT_FAILURE);
	}

	control_writeln(str);
}

unsigned long control_readulong(void)
{
	unsigned long value;
	char *str;

	str = control_readln();

	if (!str)
		exit(EXIT_FAILURE);

	value = strtoul(str, NULL, 10);
	free(str);

	return value;
}

/* Return the next line from the control socket (without the trailing newline).
 *
 * The program terminates if a timeout occurs.
 *
 * The caller must free() the returned string.
 */
char *control_readln(void)
{
	char *buf = NULL;
	size_t idx = 0;
	size_t buflen = 0;

	timeout_begin(TIMEOUT);

	for (;;) {
		ssize_t ret;

		if (idx >= buflen) {
			char *new_buf;

			new_buf = realloc(buf, buflen + 80);
			if (!new_buf) {
				perror("realloc");
				exit(EXIT_FAILURE);
			}

			buf = new_buf;
			buflen += 80;
		}

		do {
			ret = recv(control_fd, &buf[idx], 1, 0);
			timeout_check("recv");
		} while (ret < 0 && errno == EINTR);

		if (ret == 0) {
			fprintf(stderr, "unexpected EOF on control socket\n");
			exit(EXIT_FAILURE);
		}

		if (ret != 1) {
			perror("recv");
			exit(EXIT_FAILURE);
		}

		if (buf[idx] == '\n') {
			buf[idx] = '\0';
			break;
		}

		idx++;
	}

	timeout_end();

	return buf;
}

/* Wait until a given line is received or a timeout occurs */
void control_expectln(const char *str)
{
	char *line;

	line = control_readln();

	control_cmpln(line, str, true);

	free(line);
}

bool control_cmpln(char *line, const char *str, bool fail)
{
	if (strcmp(str, line) == 0)
		return true;

	if (fail) {
		fprintf(stderr, "expected \"%s\" on control socket, got \"%s\"\n",
			str, line);
		exit(EXIT_FAILURE);
	}

	return false;
}