sftp-client.c

OpenSSL Source code for SFTP, SSH, and many others

/*
 * Copyright (c) 2001,2002 Damien Miller.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* XXX: memleaks */
/* XXX: signed vs unsigned */
/* XXX: remove all logging, only return status codes */
/* XXX: copy between two remote sites */

#include "includes.h"
RCSID("$OpenBSD: sftp-client.c,v 1.32 2002/06/09 13:32:01 markus Exp $");

#include "openbsd-compat/fake-queue.h"

#include "buffer.h"
#include "bufaux.h"
#include "getput.h"
#include "xmalloc.h"
#include "log.h"
#include "atomicio.h"

#include "sftp.h"
#include "sftp-common.h"
#include "sftp-client.h"

/* Minimum amount of data to read at at time */
#define MIN_READ_SIZE	512

struct sftp_conn {
	int fd_in;
	int fd_out;
	u_int transfer_buflen;
	u_int num_requests;
	u_int version;
	u_int msg_id;
};

static void
send_msg(int fd, Buffer *m)
{
	int mlen = buffer_len(m);
	int len;
	Buffer oqueue;

	buffer_init(&oqueue);
	buffer_put_int(&oqueue, mlen);
	buffer_append(&oqueue, buffer_ptr(m), mlen);
	buffer_consume(m, mlen);

	len = atomicio(write, fd, buffer_ptr(&oqueue), buffer_len(&oqueue));
	if (len <= 0)
		fatal("Couldn't send packet: %s", strerror(errno));

	buffer_free(&oqueue);
}

static void
get_msg(int fd, Buffer *m)
{
	u_int len, msg_len;
	unsigned char buf[4096];

	len = atomicio(read, fd, buf, 4);
	if (len == 0)
		fatal("Connection closed");
	else if (len == -1)
		fatal("Couldn't read packet: %s", strerror(errno));

	msg_len = GET_32BIT(buf);
	if (msg_len > 256 * 1024)
		fatal("Received message too long %d", msg_len);

	while (msg_len) {
		len = atomicio(read, fd, buf, MIN(msg_len, sizeof(buf)));
		if (len == 0)
			fatal("Connection closed");
		else if (len == -1)
			fatal("Couldn't read packet: %s", strerror(errno));

		msg_len -= len;
		buffer_append(m, buf, len);
	}
}

static void
send_string_request(int fd, u_int id, u_int code, char *s,
    u_int len)
{
	Buffer msg;

	buffer_init(&msg);
	buffer_put_char(&msg, code);
	buffer_put_int(&msg, id);
	buffer_put_string(&msg, s, len);
	send_msg(fd, &msg);
	debug3("Sent message fd %d T:%d I:%d", fd, code, id);
	buffer_free(&msg);
}

static void
send_string_attrs_request(int fd, u_int id, u_int code, char *s,
    u_int len, Attrib *a)
{
	Buffer msg;

	buffer_init(&msg);
	buffer_put_char(&msg, code);
	buffer_put_int(&msg, id);
	buffer_put_string(&msg, s, len);
	encode_attrib(&msg, a);
	send_msg(fd, &msg);
	debug3("Sent message fd %d T:%d I:%d", fd, code, id);
	buffer_free(&msg);
}

static u_int
get_status(int fd, int expected_id)
{
	Buffer msg;
	u_int type, id, status;

	buffer_init(&msg);
	get_msg(fd, &msg);
	type = buffer_get_char(&msg);
	id = buffer_get_int(&msg);

	if (id != expected_id)
		fatal("ID mismatch (%d != %d)", id, expected_id);
	if (type != SSH2_FXP_STATUS)
		fatal("Expected SSH2_FXP_STATUS(%d) packet, got %d",
		    SSH2_FXP_STATUS, type);

	status = buffer_get_int(&msg);
	buffer_free(&msg);

	debug3("SSH2_FXP_STATUS %d", status);

	return(status);
}

static char *
get_handle(int fd, u_int expected_id, u_int *len)
{
	Buffer msg;
	u_int type, id;
	char *handle;

	buffer_init(&msg);
	get_msg(fd, &msg);
	type = buffer_get_char(&msg);
	id = buffer_get_int(&msg);

	if (id != expected_id)
		fatal("ID mismatch (%d != %d)", id, expected_id);
	if (type == SSH2_FXP_STATUS) {
		int status = buffer_get_int(&msg);

		error("Couldn't get handle: %s", fx2txt(status));
		return(NULL);
	} else if (type != SSH2_FXP_HANDLE)
		fatal("Expected SSH2_FXP_HANDLE(%d) packet, got %d",
		    SSH2_FXP_HANDLE, type);

	handle = buffer_get_string(&msg, len);
	buffer_free(&msg);

	return(handle);
}

static Attrib *
get_decode_stat(int fd, u_int expected_id, int quiet)
{
	Buffer msg;
	u_int type, id;
	Attrib *a;

	buffer_init(&msg);
	get_msg(fd, &msg);

	type = buffer_get_char(&msg);
	id = buffer_get_int(&msg);

	debug3("Received stat reply T:%d I:%d", type, id);
	if (id != expected_id)
		fatal("ID mismatch (%d != %d)", id, expected_id);
	if (type == SSH2_FXP_STATUS) {
		int status = buffer_get_int(&msg);

		if (quiet)
			debug("Couldn't stat remote file: %s", fx2txt(status));
		else
			error("Couldn't stat remote file: %s", fx2txt(status));
		return(NULL);
	} else if (type != SSH2_FXP_ATTRS) {
		fatal("Expected SSH2_FXP_ATTRS(%d) packet, got %d",
		    SSH2_FXP_ATTRS, type);
	}
	a = decode_attrib(&msg);
	buffer_free(&msg);

	return(a);
}

struct sftp_conn *
do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests)
{
	int type, version;
	Buffer msg;
	struct sftp_conn *ret;

	buffer_init(&msg);
	buffer_put_char(&msg, SSH2_FXP_INIT);
	buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
	send_msg(fd_out, &msg);

	buffer_clear(&msg);

	get_msg(fd_in, &msg);

	/* Expecting a VERSION reply */
	if ((type = buffer_get_char(&msg)) != SSH2_FXP_VERSION) {
		error("Invalid packet back from SSH2_FXP_INIT (type %d)",
		    type);
		buffer_free(&msg);
		return(NULL);
	}
	version = buffer_get_int(&msg);

	debug2("Remote version: %d", version);

	/* Check for extensions */
	while (buffer_len(&msg) > 0) {
		char *name = buffer_get_string(&msg, NULL);
		char *value = buffer_get_string(&msg, NULL);

		debug2("Init extension: \"%s\"", name);
		xfree(name);
		xfree(value);
	}

	buffer_free(&msg);

	ret = xmalloc(sizeof(*ret));
	ret->fd_in = fd_in;
	ret->fd_out = fd_out;
	ret->transfer_buflen = transfer_buflen;
	ret->num_requests = num_requests;
	ret->version = version;
	ret->msg_id = 1;

	/* Some filexfer v.0 servers don't support large packets */
	if (version == 0)
		ret->transfer_buflen = MIN(ret->transfer_buflen, 20480);

	return(ret);
}

u_int
sftp_proto_version(struct sftp_conn *conn)
{
	return(conn->version);
}

int
do_close(struct sftp_conn *conn, char *handle, u_int handle_len)
{
	u_int id, status;
	Buffer msg;

	buffer_init(&msg);

	id = conn->msg_id++;
	buffer_put_char(&msg, SSH2_FXP_CLOSE);
	buffer_put_int(&msg, id);
	buffer_put_string(&msg, handle, handle_len);
	send_msg(conn->fd_out, &msg);
	debug3("Sent message SSH2_FXP_CLOSE I:%d", id);

	status = get_status(conn->fd_in, id);
	if (status != SSH2_FX_OK)
		error("Couldn't close file: %s", fx2txt(status));

	buffer_free(&msg);

	return(status);
}


static int
do_lsreaddir(struct sftp_conn *conn, char *path, int printflag,
    SFTP_DIRENT ***dir)
{
	Buffer msg;
	u_int type, id, handle_len, i, expected_id, ents = 0;
	char *handle;

	id = conn->msg_id++;

	buffer_init(&msg);
	buffer_put_char(&msg, SSH2_FXP_OPENDIR);
	buffer_put_int(&msg, id);
	buffer_put_cstring(&msg, path);
	send_msg(conn->fd_out, &msg);

	buffer_clear(&msg);

	handle = get_handle(conn->fd_in, id, &handle_len);
	if (handle == NULL)
		return(-1);

	if (dir) {
		ents = 0;
		*dir = xmalloc(sizeof(**dir));
		(*dir)[0] = NULL;
	}

	for (;;) {
		int count;

		id = expected_id = conn->msg_id++;

		debug3("Sending SSH2_FXP_READDIR I:%d", id);

		buffer_clear(&msg);
		buffer_put_char(&msg, SSH2_FXP_READDIR);
		buffer_put_int(&msg, id);
		buffer_put_string(&msg, handle, handle_len);
		send_msg(conn->fd_out, &msg);

		buffer_clear(&msg);

		get_msg(conn->fd_in, &msg);

		type = buffer_get_char(&msg);
		id = buffer_get_int(&msg);

		debug3("Received reply T:%d I:%d", type, id);

		if (id != expected_id)
			fatal("ID mismatch (%d != %d)", id, expected_id);

		if (type == SSH2_FXP_STATUS) {
			int status = buffer_get_int(&msg);

			debug3("Received SSH2_FXP_STATUS %d", status);

			if (status == SSH2_FX_EOF) {
				break;
			} else {
				error("Couldn't read directory: %s",
				    fx2txt(status));
				do_close(conn, handle, handle_len);
				return(status);
			}
		} else if (type != SSH2_FXP_NAME)
			fatal("Expected SSH2_FXP_NAME(%d) packet, got %d",
			    SSH2_FXP_NAME, type);

		count = buffer_get_int(&msg);
		if (count == 0)
			break;
		debug3("Received %d SSH2_FXP_NAME responses", count);
		for (i = 0; i < count; i++) {
			char *filename, *longname;
			Attrib *a;

			filename = buffer_get_string(&msg, NULL);
			longname = buffer_get_string(&msg, NULL);
			a = decode_attrib(&msg);

			if (printflag)
				printf("%s\n", longname);

			if (dir) {
				*dir = xrealloc(*dir, sizeof(**dir) *
				    (ents + 2));
				(*dir)[ents] = xmalloc(sizeof(***dir));
				(*dir)[ents]->filename = xstrdup(filename);
				(*dir)[ents]->longname = xstrdup(longname);
				memcpy(&(*dir)[ents]->a, a, sizeof(*a));
				(*dir)[++ents] = NULL;
			}

			xfree(filename);
			xfree(longname);
		}
	}

	buffer_free(&msg);
	do_close(conn, handle, handle_len);
	xfree(handle);

	return(0);
}

int
do_ls(struct sftp_conn *conn, char *path)
{
	return(do_lsreaddir(conn, path, 1, NULL));
}

int
do_readdir(struct sftp_conn *conn, char *path, SFTP_DIRENT ***dir)
{
	return(do_lsreaddir(conn, path, 0, dir));
}

void free_sftp_dirents(SFTP_DIRENT **s)
{
	int i;

	for (i = 0; s[i]; i++) {
		xfree(s[i]->filename);
		xfree(s[i]->longname);
		xfree(s[i]);
	}
	xfree(s);
}

int
do_rm(struct sftp_conn *conn, char *path)
{
	u_int status, id;

	debug2("Sending SSH2_FXP_REMOVE \"%s\"", path);

	id = conn->msg_id++;
	send_string_request(conn->fd_out, id, SSH2_FXP_REMOVE, path,
	    strlen(path));
	status = get_status(conn->fd_in, id);
	if (status != SSH2_FX_OK)
		error("Couldn't delete file: %s", fx2txt(status));
	return(status);
}

int
do_mkdir(struct sftp_conn *conn, char *path, Attrib *a)
{
	u_int status, id;

	id = conn->msg_id++;
	send_string_attrs_request(conn->fd_out, id, SSH2_FXP_MKDIR, path,
	    strlen(path), a);

	status = get_status(conn->fd_in, id);
	if (status != SSH2_FX_OK)
		error("Couldn't create directory: %s", fx2txt(status));

	return(status);
}

int
do_rmdir(struct sftp_conn *conn, char *path)
{
	u_int status, id;

	id = conn->msg_id++;
	send_string_request(conn->fd_out, id, SSH2_FXP_RMDIR, path,
	    strlen(path));

	status = get_status(conn->fd_in, id);
	if (status != SSH2_FX_OK)
		error("Couldn't remove directory: %s", fx2txt(status));

	return(status);
}

Attrib *
do_stat(struct sftp_conn *conn, char *path, int quiet)
{
	u_int id;

	id = conn->msg_id++;

	send_string_request(conn->fd_out, id,
	    conn->version == 0 ? SSH2_FXP_STAT_VERSION_0 : SSH2_FXP_STAT,
	    path, strlen(path));

	return(get_decode_stat(conn->fd_in, id, quiet));
}

Attrib *
do_lstat(struct sftp_conn *conn, char *path, int quiet)
{
	u_int id;

	if (conn->version == 0) {
		if (quiet)
			debug("Server version does not support lstat operation");
		else
			log("Server version does not support lstat operation");
		return(do_stat(conn, path, quiet));
	}

	id = conn->msg_id++;
	send_string_request(conn->fd_out, id, SSH2_FXP_LSTAT, path,
	    strlen(path));

	return(get_decode_stat(conn->fd_in, id, quiet));
}

Attrib *
do_fstat(struct sftp_conn *conn, char *handle, u_int handle_len, int quiet)
{
	u_int id;

	id = conn->msg_id++;
	send_string_request(conn->fd_out, id, SSH2_FXP_FSTAT, handle,
	    handle_len);

	return(get_decode_stat(conn->fd_in, id, quiet));
}

int
do_setstat(struct sftp_conn *conn, char *path, Attrib *a)
{
	u_int status, id;

	id = conn->msg_id++;
	send_string_attrs_request(conn->fd_out, id, SSH2_FXP_SETSTAT, path,
	    strlen(path), a);

	status = get_status(conn->fd_in, id);
	if (status != SSH2_FX_OK)
		error("Couldn't setstat on \"%s\": %s", path,
		    fx2txt(status));

	return(status);
}

int
do_fsetstat(struct sftp_conn *conn, char *handle, u_int handle_len,
    Attrib *a)
{
	u_int status, id;

	id = conn->msg_id++;
	send_string_attrs_request(conn->fd_out, id, SSH2_FXP_FSETSTAT, handle,
	    handle_len, a);

	status = get_status(conn->fd_in, id);