diff options
Diffstat (limited to 'tools/testing/vsock/control.c')
| -rw-r--r-- | tools/testing/vsock/control.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/tools/testing/vsock/control.c b/tools/testing/vsock/control.c new file mode 100644 index 000000000..90fd47f0e --- /dev/null +++ b/tools/testing/vsock/control.c @@ -0,0 +1,219 @@ +/* Control socket for client/server test execution + * + * Copyright (C) 2017 Red Hat, Inc. + * + * Author: Stefan Hajnoczi <stefanha@redhat.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +/* 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" + +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; + int val = 1; + + 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; + } + + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, + &val, sizeof(val)) < 0) { + perror("setsockopt"); + exit(EXIT_FAILURE); + } + + 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(); +} + +/* 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(); + if (strcmp(str, line) != 0) { + fprintf(stderr, "expected \"%s\" on control socket, got \"%s\"\n", + str, line); + exit(EXIT_FAILURE); + } + + free(line); +} |