1 /* Control socket for client/server test execution
3 * Copyright (C) 2017 Red Hat, Inc.
5 * Author: Stefan Hajnoczi <stefanha@redhat.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; version 2
13 /* The client and server may need to coordinate to avoid race conditions like
14 * the client attempting to connect to a socket that the server is not
15 * listening on yet. The control socket offers a communications channel for
16 * such coordination tasks.
18 * If the client calls control_expectln("LISTENING"), then it will block until
19 * the server calls control_writeln("LISTENING"). This provides a simple
20 * mechanism for coordinating between the client and the server.
29 #include <sys/types.h>
30 #include <sys/socket.h>
35 static int control_fd = -1;
37 /* Open the control socket, either in server or client mode */
38 void control_init(const char *control_host,
39 const char *control_port,
42 struct addrinfo hints = {
43 .ai_socktype = SOCK_STREAM,
45 struct addrinfo *result = NULL;
49 ret = getaddrinfo(control_host, control_port, &hints, &result);
51 fprintf(stderr, "%s\n", gai_strerror(ret));
55 for (ai = result; ai; ai = ai->ai_next) {
59 fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
64 if (connect(fd, ai->ai_addr, ai->ai_addrlen) < 0)
67 printf("Control socket connected to %s:%s.\n",
68 control_host, control_port);
72 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
73 &val, sizeof(val)) < 0) {
78 if (bind(fd, ai->ai_addr, ai->ai_addrlen) < 0)
80 if (listen(fd, 1) < 0)
83 printf("Control socket listening on %s:%s\n",
84 control_host, control_port);
87 control_fd = accept(fd, NULL, 0);
94 printf("Control socket connection accepted...\n");
101 if (control_fd < 0) {
102 fprintf(stderr, "Control socket initialization failed. Invalid address %s:%s?\n",
103 control_host, control_port);
107 freeaddrinfo(result);
111 void control_cleanup(void)
117 /* Write a line to the control socket */
118 void control_writeln(const char *str)
120 ssize_t len = strlen(str);
123 timeout_begin(TIMEOUT);
126 ret = send(control_fd, str, len, MSG_MORE);
127 timeout_check("send");
128 } while (ret < 0 && errno == EINTR);
136 ret = send(control_fd, "\n", 1, 0);
137 timeout_check("send");
138 } while (ret < 0 && errno == EINTR);
148 /* Return the next line from the control socket (without the trailing newline).
150 * The program terminates if a timeout occurs.
152 * The caller must free() the returned string.
154 char *control_readln(void)
160 timeout_begin(TIMEOUT);
168 new_buf = realloc(buf, buflen + 80);
179 ret = recv(control_fd, &buf[idx], 1, 0);
180 timeout_check("recv");
181 } while (ret < 0 && errno == EINTR);
184 fprintf(stderr, "unexpected EOF on control socket\n");
193 if (buf[idx] == '\n') {
206 /* Wait until a given line is received or a timeout occurs */
207 void control_expectln(const char *str)
211 line = control_readln();
212 if (strcmp(str, line) != 0) {
213 fprintf(stderr, "expected \"%s\" on control socket, got \"%s\"\n",