console-client.c - openbmc/obmc-console - Gitiles

 /**
  * Copyright © 2016 IBM Corporation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <err.h>
 #include <errno.h>
 #include <getopt.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <termios.h>
 #include <unistd.h>

 #include <sys/socket.h>
 #include <sys/un.h>

 #include "console-server.h"
 #include "config.h"

 #define EXIT_ESCAPE 2

 enum process_rc {
 	PROCESS_OK = 0,
 	PROCESS_ERR,
 	PROCESS_EXIT,
 	PROCESS_ESC,
 };

 enum esc_type {
 	ESC_TYPE_SSH,
 	ESC_TYPE_STR,
 };

 struct ssh_esc_state {
 	uint8_t state;
 };

 struct str_esc_state {
 	const uint8_t *str;
 	size_t pos;
 };

 struct console_client {
 	int console_sd;
 	int fd_in;
 	int fd_out;
 	bool is_tty;
 	struct termios orig_termios;
 	enum esc_type esc_type;
 	union {
 		struct ssh_esc_state ssh;
 		struct str_esc_state str;
 	} esc_state;
 };

 static enum process_rc process_ssh_tty(struct console_client *client,
 				       const uint8_t *buf, size_t len)
 {
 	struct ssh_esc_state *esc_state = &client->esc_state.ssh;
 	const uint8_t *out_buf = buf;
 	int rc;

 	for (size_t i = 0; i < len; ++i) {
 		switch (buf[i]) {
 		case '.':
 			if (esc_state->state != '~') {
 				esc_state->state = '\0';
 				break;
 			}
 			return PROCESS_ESC;
 		case '~':
 			if (esc_state->state != '\r') {
 				esc_state->state = '\0';
 				break;
 			}
 			esc_state->state = '~';
 			/* We need to print everything to skip the tilde */
 			rc = write_buf_to_fd(client->console_sd, out_buf,
 					     i - (out_buf - buf));
 			if (rc < 0) {
 				return PROCESS_ERR;
 			}
 			out_buf = &buf[i + 1];
 			break;
 		case '\r':
 			esc_state->state = '\r';
 			break;
 		default:
 			esc_state->state = '\0';
 		}
 	}

 	rc = write_buf_to_fd(client->console_sd, out_buf,
 			     len - (out_buf - buf));
 	return rc < 0 ? PROCESS_ERR : PROCESS_OK;
 }

 static enum process_rc process_str_tty(struct console_client *client,
 				       const uint8_t *buf, size_t len)
 {
 	struct str_esc_state *esc_state = &client->esc_state.str;
 	enum process_rc prc = PROCESS_OK;
 	size_t i;

 	for (i = 0; i < len; ++i) {
 		if (buf[i] == esc_state->str[esc_state->pos]) {
 			esc_state->pos++;
 		} else {
 			esc_state->pos = 0;
 		}

 		if (esc_state->str[esc_state->pos] == '\0') {
 			prc = PROCESS_ESC;
 			++i;
 			break;
 		}
 	}

 	if (write_buf_to_fd(client->console_sd, buf, i) < 0) {
 		return PROCESS_ERR;
 	}
 	return prc;
 }

 static enum process_rc process_tty(struct console_client *client)
 {
 	uint8_t buf[4096];
 	ssize_t len;

 	len = read(client->fd_in, buf, sizeof(buf));
 	if (len < 0) {
 		return PROCESS_ERR;
 	}
 	if (len == 0) {
 		return PROCESS_EXIT;
 	}

 	switch (client->esc_type) {
 	case ESC_TYPE_SSH:
 		return process_ssh_tty(client, buf, len);
 	case ESC_TYPE_STR:
 		return process_str_tty(client, buf, len);
 	default:
 		return PROCESS_ERR;
 	}
 }

 static int process_console(struct console_client *client)
 {
 	uint8_t buf[4096];
 	ssize_t len;
 	int rc;

 	len = read(client->console_sd, buf, sizeof(buf));
 	if (len < 0) {
 		warn("Can't read from server");
 		return PROCESS_ERR;
 	}
 	if (len == 0) {
 		fprintf(stderr, "Connection closed\n");
 		return PROCESS_EXIT;
 	}

 	rc = write_buf_to_fd(client->fd_out, buf, len);
 	return rc ? PROCESS_ERR : PROCESS_OK;
 }

 /*
  * Setup our local file descriptors for IO: use stdin/stdout, and if we're on a
  * TTY, put it in canonical mode
  */
 static int client_tty_init(struct console_client *client)
 {
 	struct termios termios;
 	int rc;

 	client->fd_in = STDIN_FILENO;
 	client->fd_out = STDOUT_FILENO;
 	client->is_tty = isatty(client->fd_in);

 	if (!client->is_tty) {
 		return 0;
 	}

 	rc = tcgetattr(client->fd_in, &termios);
 	if (rc) {
 		warn("Can't get terminal attributes for console");
 		return -1;
 	}
 	memcpy(&client->orig_termios, &termios, sizeof(client->orig_termios));
 	cfmakeraw(&termios);

 	rc = tcsetattr(client->fd_in, TCSANOW, &termios);
 	if (rc) {
 		warn("Can't set terminal attributes for console");
 		return -1;
 	}

 	return 0;
 }

 static int client_init(struct console_client *client, struct config *config,
 		       const char *console_id)
 {
 	const char *resolved_id = NULL;
 	struct sockaddr_un addr;
 	socket_path_t path;
 	ssize_t len;
 	int rc;

 	client->console_sd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if (!client->console_sd) {
 		warn("Can't open socket");
 		return -1;
 	}

 	/* Get the console id */
 	resolved_id = config_resolve_console_id(config, console_id);

 	memset(&addr, 0, sizeof(addr));
 	addr.sun_family = AF_UNIX;
 	len = console_socket_path(addr.sun_path, resolved_id);
 	if (len < 0) {
 		if (errno) {
 			warn("Failed to configure socket: %s", strerror(errno));
 		} else {
 			warn("Socket name length exceeds buffer limits");
 		}
 		goto cleanup;
 	}

 	rc = connect(client->console_sd, (struct sockaddr *)&addr,
 		     sizeof(addr) - sizeof(addr.sun_path) + len);
 	if (!rc) {
 		return 0;
 	}

 	console_socket_path_readable(&addr, len, path);
 	warn("Can't connect to console server '@%s'", path);
 cleanup:
 	close(client->console_sd);
 	return -1;
 }

 static void client_fini(struct console_client *client)
 {
 	if (client->is_tty) {
 		tcsetattr(client->fd_in, TCSANOW, &client->orig_termios);
 	}
 	close(client->console_sd);
 }

 int main(int argc, char *argv[])
 {
 	struct console_client _client;
 	struct console_client *client;
 	struct pollfd pollfds[2];
 	enum process_rc prc = PROCESS_OK;
 	const char *config_path = NULL;
 	struct config *config = NULL;
 	const char *console_id = NULL;
 	const uint8_t *esc = NULL;
 	int rc;

 	client = &_client;
 	memset(client, 0, sizeof(*client));
 	client->esc_type = ESC_TYPE_SSH;

 	for (;;) {
 		rc = getopt(argc, argv, "c:e:i:");
 		if (rc == -1) {
 			break;
 		}

 		switch (rc) {
 		case 'c':
 			if (optarg[0] == '\0') {
 				fprintf(stderr, "Config str cannot be empty\n");
 				return EXIT_FAILURE;
 			}
 			config_path = optarg;
 			break;
 		case 'e':
 			if (optarg[0] == '\0') {
 				fprintf(stderr, "Escape str cannot be empty\n");
 				return EXIT_FAILURE;
 			}
 			esc = (const uint8_t *)optarg;
 			break;
 		case 'i':
 			if (optarg[0] == '\0') {
 				fprintf(stderr,
 					"Socket ID str cannot be empty\n");
 				return EXIT_FAILURE;
 			}
 			console_id = optarg;
 			break;
 		default:
 			fprintf(stderr,
 				"Usage: %s "
 				"[-e <escape sequence>]"
 				"[-i <console ID>]"
 				"[-c <config>]\n",
 				argv[0]);
 			return EXIT_FAILURE;
 		}
 	}

 	if (config_path) {
 		config = config_init(config_path);
 		if (!config) {
 			warnx("Can't read configuration, exiting.");
 			return EXIT_FAILURE;
 		}

 		if (!esc) {
 			esc = (const uint8_t *)config_get_value(
 				config, "escape-sequence");
 		}
 	}

 	if (esc) {
 		client->esc_type = ESC_TYPE_STR;
 		client->esc_state.str.str = esc;
 	}

 	rc = client_init(client, config, console_id);
 	if (rc) {
 		goto out_config_fini;
 	}

 	rc = client_tty_init(client);
 	if (rc) {
 		goto out_client_fini;
 	}

 	for (;;) {
 		pollfds[0].fd = client->fd_in;
 		pollfds[0].events = POLLIN;
 		pollfds[1].fd = client->console_sd;
 		pollfds[1].events = POLLIN;

 		rc = poll(pollfds, 2, -1);
 		if (rc < 0) {
 			warn("Poll failure");
 			break;
 		}

 		if (pollfds[0].revents) {
 			prc = process_tty(client);
 		}

 		if (prc == PROCESS_OK && pollfds[1].revents) {
 			prc = process_console(client);
 		}

 		rc = (prc == PROCESS_ERR) ? -1 : 0;
 		if (prc != PROCESS_OK) {
 			break;
 		}
 	}

 out_client_fini:
 	client_fini(client);

 out_config_fini:
 	if (config_path) {
 		config_fini(config);
 	}

 	if (prc == PROCESS_ESC) {
 		return EXIT_ESCAPE;
 	}
 	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
 }
	/**
	* Copyright © 2016 IBM Corporation
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <err.h>
	#include <errno.h>
	#include <getopt.h>
	#include <stdbool.h>
	#include <stdint.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <termios.h>
	#include <unistd.h>

	#include <sys/socket.h>
	#include <sys/un.h>

	#include "console-server.h"
	#include "config.h"

	#define EXIT_ESCAPE 2

	enum process_rc {
	PROCESS_OK = 0,
	PROCESS_ERR,
	PROCESS_EXIT,
	PROCESS_ESC,
	};

	enum esc_type {
	ESC_TYPE_SSH,
	ESC_TYPE_STR,
	};

	struct ssh_esc_state {
	uint8_t state;
	};

	struct str_esc_state {
	const uint8_t *str;
	size_t pos;
	};

	struct console_client {
	int console_sd;
	int fd_in;
	int fd_out;
	bool is_tty;
	struct termios orig_termios;
	enum esc_type esc_type;
	union {
	struct ssh_esc_state ssh;
	struct str_esc_state str;
	} esc_state;
	};

	static enum process_rc process_ssh_tty(struct console_client *client,
	const uint8_t *buf, size_t len)
	{
	struct ssh_esc_state *esc_state = &client->esc_state.ssh;
	const uint8_t *out_buf = buf;
	int rc;

	for (size_t i = 0; i < len; ++i) {
	switch (buf[i]) {
	case '.':
	if (esc_state->state != '~') {
	esc_state->state = '\0';
	break;
	}
	return PROCESS_ESC;
	case '~':
	if (esc_state->state != '\r') {
	esc_state->state = '\0';
	break;
	}
	esc_state->state = '~';
	/* We need to print everything to skip the tilde */
	rc = write_buf_to_fd(client->console_sd, out_buf,
	i - (out_buf - buf));
	if (rc < 0) {
	return PROCESS_ERR;
	}
	out_buf = &buf[i + 1];
	break;
	case '\r':
	esc_state->state = '\r';
	break;
	default:
	esc_state->state = '\0';
	}
	}

	rc = write_buf_to_fd(client->console_sd, out_buf,
	len - (out_buf - buf));
	return rc < 0 ? PROCESS_ERR : PROCESS_OK;
	}

	static enum process_rc process_str_tty(struct console_client *client,
	const uint8_t *buf, size_t len)
	{
	struct str_esc_state *esc_state = &client->esc_state.str;
	enum process_rc prc = PROCESS_OK;
	size_t i;

	for (i = 0; i < len; ++i) {
	if (buf[i] == esc_state->str[esc_state->pos]) {
	esc_state->pos++;
	} else {
	esc_state->pos = 0;
	}

	if (esc_state->str[esc_state->pos] == '\0') {
	prc = PROCESS_ESC;
	++i;
	break;
	}
	}

	if (write_buf_to_fd(client->console_sd, buf, i) < 0) {
	return PROCESS_ERR;
	}
	return prc;
	}

	static enum process_rc process_tty(struct console_client *client)
	{
	uint8_t buf[4096];
	ssize_t len;

	len = read(client->fd_in, buf, sizeof(buf));
	if (len < 0) {
	return PROCESS_ERR;
	}
	if (len == 0) {
	return PROCESS_EXIT;
	}

	switch (client->esc_type) {
	case ESC_TYPE_SSH:
	return process_ssh_tty(client, buf, len);
	case ESC_TYPE_STR:
	return process_str_tty(client, buf, len);
	default:
	return PROCESS_ERR;
	}
	}

	static int process_console(struct console_client *client)
	{
	uint8_t buf[4096];
	ssize_t len;
	int rc;

	len = read(client->console_sd, buf, sizeof(buf));
	if (len < 0) {
	warn("Can't read from server");
	return PROCESS_ERR;
	}
	if (len == 0) {
	fprintf(stderr, "Connection closed\n");
	return PROCESS_EXIT;
	}

	rc = write_buf_to_fd(client->fd_out, buf, len);
	return rc ? PROCESS_ERR : PROCESS_OK;
	}

	/*
	* Setup our local file descriptors for IO: use stdin/stdout, and if we're on a
	* TTY, put it in canonical mode
	*/
	static int client_tty_init(struct console_client *client)
	{
	struct termios termios;
	int rc;

	client->fd_in = STDIN_FILENO;
	client->fd_out = STDOUT_FILENO;
	client->is_tty = isatty(client->fd_in);

	if (!client->is_tty) {
	return 0;
	}

	rc = tcgetattr(client->fd_in, &termios);
	if (rc) {
	warn("Can't get terminal attributes for console");
	return -1;
	}
	memcpy(&client->orig_termios, &termios, sizeof(client->orig_termios));
	cfmakeraw(&termios);

	rc = tcsetattr(client->fd_in, TCSANOW, &termios);
	if (rc) {
	warn("Can't set terminal attributes for console");
	return -1;
	}

	return 0;
	}

	static int client_init(struct console_client client, struct config config,
	const char *console_id)
	{
	const char *resolved_id = NULL;
	struct sockaddr_un addr;
	socket_path_t path;
	ssize_t len;
	int rc;

	client->console_sd = socket(AF_UNIX, SOCK_STREAM, 0);
	if (!client->console_sd) {
	warn("Can't open socket");
	return -1;
	}

	/* Get the console id */
	resolved_id = config_resolve_console_id(config, console_id);

	memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	len = console_socket_path(addr.sun_path, resolved_id);
	if (len < 0) {
	if (errno) {
	warn("Failed to configure socket: %s", strerror(errno));
	} else {
	warn("Socket name length exceeds buffer limits");
	}
	goto cleanup;
	}

	rc = connect(client->console_sd, (struct sockaddr *)&addr,
	sizeof(addr) - sizeof(addr.sun_path) + len);
	if (!rc) {
	return 0;
	}

	console_socket_path_readable(&addr, len, path);
	warn("Can't connect to console server '@%s'", path);
	cleanup:
	close(client->console_sd);
	return -1;
	}

	static void client_fini(struct console_client *client)
	{
	if (client->is_tty) {
	tcsetattr(client->fd_in, TCSANOW, &client->orig_termios);
	}
	close(client->console_sd);
	}

	int main(int argc, char *argv[])
	{
	struct console_client _client;
	struct console_client *client;
	struct pollfd pollfds[2];
	enum process_rc prc = PROCESS_OK;
	const char *config_path = NULL;
	struct config *config = NULL;
	const char *console_id = NULL;
	const uint8_t *esc = NULL;
	int rc;

	client = &_client;
	memset(client, 0, sizeof(*client));
	client->esc_type = ESC_TYPE_SSH;

	for (;;) {
	rc = getopt(argc, argv, "c:e:i:");
	if (rc == -1) {
	break;
	}

	switch (rc) {
	case 'c':
	if (optarg[0] == '\0') {
	fprintf(stderr, "Config str cannot be empty\n");
	return EXIT_FAILURE;
	}
	config_path = optarg;
	break;
	case 'e':
	if (optarg[0] == '\0') {
	fprintf(stderr, "Escape str cannot be empty\n");
	return EXIT_FAILURE;
	}
	esc = (const uint8_t *)optarg;
	break;
	case 'i':
	if (optarg[0] == '\0') {
	fprintf(stderr,
	"Socket ID str cannot be empty\n");
	return EXIT_FAILURE;
	}
	console_id = optarg;
	break;
	default:
	fprintf(stderr,
	"Usage: %s "
	"[-e <escape sequence>]"
	"[-i <console ID>]"
	"[-c <config>]\n",
	argv[0]);
	return EXIT_FAILURE;
	}
	}

	if (config_path) {
	config = config_init(config_path);
	if (!config) {
	warnx("Can't read configuration, exiting.");
	return EXIT_FAILURE;
	}

	if (!esc) {
	esc = (const uint8_t *)config_get_value(
	config, "escape-sequence");
	}
	}

	if (esc) {
	client->esc_type = ESC_TYPE_STR;
	client->esc_state.str.str = esc;
	}

	rc = client_init(client, config, console_id);
	if (rc) {
	goto out_config_fini;
	}

	rc = client_tty_init(client);
	if (rc) {
	goto out_client_fini;
	}

	for (;;) {
	pollfds[0].fd = client->fd_in;
	pollfds[0].events = POLLIN;
	pollfds[1].fd = client->console_sd;
	pollfds[1].events = POLLIN;

	rc = poll(pollfds, 2, -1);
	if (rc < 0) {
	warn("Poll failure");
	break;
	}

	if (pollfds[0].revents) {
	prc = process_tty(client);
	}

	if (prc == PROCESS_OK && pollfds[1].revents) {
	prc = process_console(client);
	}

	rc = (prc == PROCESS_ERR) ? -1 : 0;
	if (prc != PROCESS_OK) {
	break;
	}
	}

	out_client_fini:
	client_fini(client);

	out_config_fini:
	if (config_path) {
	config_fini(config);
	}

	if (prc == PROCESS_ESC) {
	return EXIT_ESCAPE;
	}
	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
	}