1 files changed, 1337 insertions, 0 deletions

diff --git a/sftp-server.c b/sftp-server.c
new file mode 100644
index 000000000000..c57958b0f327
--- /dev/null
+++ b/sftp-server.c
@@ -0,0 +1,1337 @@
+/* $OpenBSD: sftp-server.c,v 1.70 2006/08/03 03:34:42 deraadt Exp $ */
+/*
+ * Copyright (c) 2000-2004 Markus Friedl.  All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <pwd.h>
+#include <time.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "log.h"
+#include "misc.h"
+#include "uidswap.h"
+
+#include "sftp.h"
+#include "sftp-common.h"
+
+/* helper */
+#define get_int64()			buffer_get_int64(&iqueue);
+#define get_int()			buffer_get_int(&iqueue);
+#define get_string(lenp)		buffer_get_string(&iqueue, lenp);
+
+/* Our verbosity */
+LogLevel log_level = SYSLOG_LEVEL_ERROR;
+
+/* Our client */
+struct passwd *pw = NULL;
+char *client_addr = NULL;
+
+/* input and output queue */
+Buffer iqueue;
+Buffer oqueue;
+
+/* Version of client */
+int version;
+
+/* portable attributes, etc. */
+
+typedef struct Stat Stat;
+
+struct Stat {
+	char *name;
+	char *long_name;
+	Attrib attrib;
+};
+
+static int
+errno_to_portable(int unixerrno)
+{
+	int ret = 0;
+
+	switch (unixerrno) {
+	case 0:
+		ret = SSH2_FX_OK;
+		break;
+	case ENOENT:
+	case ENOTDIR:
+	case EBADF:
+	case ELOOP:
+		ret = SSH2_FX_NO_SUCH_FILE;
+		break;
+	case EPERM:
+	case EACCES:
+	case EFAULT:
+		ret = SSH2_FX_PERMISSION_DENIED;
+		break;
+	case ENAMETOOLONG:
+	case EINVAL:
+		ret = SSH2_FX_BAD_MESSAGE;
+		break;
+	default:
+		ret = SSH2_FX_FAILURE;
+		break;
+	}
+	return ret;
+}
+
+static int
+flags_from_portable(int pflags)
+{
+	int flags = 0;
+
+	if ((pflags & SSH2_FXF_READ) &&
+	    (pflags & SSH2_FXF_WRITE)) {
+		flags = O_RDWR;
+	} else if (pflags & SSH2_FXF_READ) {
+		flags = O_RDONLY;
+	} else if (pflags & SSH2_FXF_WRITE) {
+		flags = O_WRONLY;
+	}
+	if (pflags & SSH2_FXF_CREAT)
+		flags |= O_CREAT;
+	if (pflags & SSH2_FXF_TRUNC)
+		flags |= O_TRUNC;
+	if (pflags & SSH2_FXF_EXCL)
+		flags |= O_EXCL;
+	return flags;
+}
+
+static const char *
+string_from_portable(int pflags)
+{
+	static char ret[128];
+
+	*ret = '\0';
+
+#define PAPPEND(str)	{				\
+		if (*ret != '\0')			\
+			strlcat(ret, ",", sizeof(ret));	\
+		strlcat(ret, str, sizeof(ret));		\
+	}
+
+	if (pflags & SSH2_FXF_READ)
+		PAPPEND("READ")
+	if (pflags & SSH2_FXF_WRITE)
+		PAPPEND("WRITE")
+	if (pflags & SSH2_FXF_CREAT)
+		PAPPEND("CREATE")
+	if (pflags & SSH2_FXF_TRUNC)
+		PAPPEND("TRUNCATE")
+	if (pflags & SSH2_FXF_EXCL)
+		PAPPEND("EXCL")
+
+	return ret;
+}
+
+static Attrib *
+get_attrib(void)
+{
+	return decode_attrib(&iqueue);
+}
+
+/* handle handles */
+
+typedef struct Handle Handle;
+struct Handle {
+	int use;
+	DIR *dirp;
+	int fd;
+	char *name;
+	u_int64_t bytes_read, bytes_write;
+};
+
+enum {
+	HANDLE_UNUSED,
+	HANDLE_DIR,
+	HANDLE_FILE
+};
+
+Handle	handles[100];
+
+static void
+handle_init(void)
+{
+	u_int i;
+
+	for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
+		handles[i].use = HANDLE_UNUSED;
+}
+
+static int
+handle_new(int use, const char *name, int fd, DIR *dirp)
+{
+	u_int i;
+
+	for (i = 0; i < sizeof(handles)/sizeof(Handle); i++) {
+		if (handles[i].use == HANDLE_UNUSED) {
+			handles[i].use = use;
+			handles[i].dirp = dirp;
+			handles[i].fd = fd;
+			handles[i].name = xstrdup(name);
+			handles[i].bytes_read = handles[i].bytes_write = 0;
+			return i;
+		}
+	}
+	return -1;
+}
+
+static int
+handle_is_ok(int i, int type)
+{
+	return i >= 0 && (u_int)i < sizeof(handles)/sizeof(Handle) &&
+	    handles[i].use == type;
+}
+
+static int
+handle_to_string(int handle, char **stringp, int *hlenp)
+{
+	if (stringp == NULL || hlenp == NULL)
+		return -1;
+	*stringp = xmalloc(sizeof(int32_t));
+	put_u32(*stringp, handle);
+	*hlenp = sizeof(int32_t);
+	return 0;
+}
+
+static int
+handle_from_string(const char *handle, u_int hlen)
+{
+	int val;
+
+	if (hlen != sizeof(int32_t))
+		return -1;
+	val = get_u32(handle);
+	if (handle_is_ok(val, HANDLE_FILE) ||
+	    handle_is_ok(val, HANDLE_DIR))
+		return val;
+	return -1;
+}
+
+static char *
+handle_to_name(int handle)
+{
+	if (handle_is_ok(handle, HANDLE_DIR)||
+	    handle_is_ok(handle, HANDLE_FILE))
+		return handles[handle].name;
+	return NULL;
+}
+
+static DIR *
+handle_to_dir(int handle)
+{
+	if (handle_is_ok(handle, HANDLE_DIR))
+		return handles[handle].dirp;
+	return NULL;
+}
+
+static int
+handle_to_fd(int handle)
+{
+	if (handle_is_ok(handle, HANDLE_FILE))
+		return handles[handle].fd;
+	return -1;
+}
+
+static void
+handle_update_read(int handle, ssize_t bytes)
+{
+	if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
+		handles[handle].bytes_read += bytes;
+}
+
+static void
+handle_update_write(int handle, ssize_t bytes)
+{
+	if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
+		handles[handle].bytes_write += bytes;
+}
+
+static u_int64_t
+handle_bytes_read(int handle)
+{
+	if (handle_is_ok(handle, HANDLE_FILE))
+		return (handles[handle].bytes_read);
+	return 0;
+}
+
+static u_int64_t
+handle_bytes_write(int handle)
+{
+	if (handle_is_ok(handle, HANDLE_FILE))
+		return (handles[handle].bytes_write);
+	return 0;
+}
+
+static int
+handle_close(int handle)
+{
+	int ret = -1;
+
+	if (handle_is_ok(handle, HANDLE_FILE)) {
+		ret = close(handles[handle].fd);
+		handles[handle].use = HANDLE_UNUSED;
+		xfree(handles[handle].name);
+	} else if (handle_is_ok(handle, HANDLE_DIR)) {
+		ret = closedir(handles[handle].dirp);
+		handles[handle].use = HANDLE_UNUSED;
+		xfree(handles[handle].name);
+	} else {
+		errno = ENOENT;
+	}
+	return ret;
+}
+
+static void
+handle_log_close(int handle, char *emsg)
+{
+	if (handle_is_ok(handle, HANDLE_FILE)) {
+		logit("%s%sclose \"%s\" bytes read %llu written %llu",
+		    emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
+		    handle_to_name(handle),
+		    handle_bytes_read(handle), handle_bytes_write(handle));
+	} else {
+		logit("%s%sclosedir \"%s\"",
+		    emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
+		    handle_to_name(handle));
+	}
+}
+
+static void
+handle_log_exit(void)
+{
+	u_int i;
+
+	for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
+		if (handles[i].use != HANDLE_UNUSED)
+			handle_log_close(i, "forced");
+}
+
+static int
+get_handle(void)
+{
+	char *handle;
+	int val = -1;
+	u_int hlen;
+
+	handle = get_string(&hlen);
+	if (hlen < 256)
+		val = handle_from_string(handle, hlen);
+	xfree(handle);
+	return val;
+}
+
+/* send replies */
+
+static void
+send_msg(Buffer *m)
+{
+	int mlen = buffer_len(m);
+
+	buffer_put_int(&oqueue, mlen);
+	buffer_append(&oqueue, buffer_ptr(m), mlen);
+	buffer_consume(m, mlen);
+}
+
+static const char *
+status_to_message(u_int32_t status)
+{
+	const char *status_messages[] = {
+		"Success",			/* SSH_FX_OK */
+		"End of file",			/* SSH_FX_EOF */
+		"No such file",			/* SSH_FX_NO_SUCH_FILE */
+		"Permission denied",		/* SSH_FX_PERMISSION_DENIED */
+		"Failure",			/* SSH_FX_FAILURE */
+		"Bad message",			/* SSH_FX_BAD_MESSAGE */
+		"No connection",		/* SSH_FX_NO_CONNECTION */
+		"Connection lost",		/* SSH_FX_CONNECTION_LOST */
+		"Operation unsupported",	/* SSH_FX_OP_UNSUPPORTED */
+		"Unknown error"			/* Others */
+	};
+	return (status_messages[MIN(status,SSH2_FX_MAX)]);
+}
+
+static void
+send_status(u_int32_t id, u_int32_t status)
+{
+	Buffer msg;
+
+	debug3("request %u: sent status %u", id, status);
+	if (log_level > SYSLOG_LEVEL_VERBOSE ||
+	    (status != SSH2_FX_OK && status != SSH2_FX_EOF))
+		logit("sent status %s", status_to_message(status));
+	buffer_init(&msg);
+	buffer_put_char(&msg, SSH2_FXP_STATUS);
+	buffer_put_int(&msg, id);
+	buffer_put_int(&msg, status);
+	if (version >= 3) {
+		buffer_put_cstring(&msg, status_to_message(status));
+		buffer_put_cstring(&msg, "");
+	}
+	send_msg(&msg);
+	buffer_free(&msg);
+}
+static void
+send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
+{
+	Buffer msg;
+
+	buffer_init(&msg);
+	buffer_put_char(&msg, type);
+	buffer_put_int(&msg, id);
+	buffer_put_string(&msg, data, dlen);
+	send_msg(&msg);
+	buffer_free(&msg);
+}
+
+static void
+send_data(u_int32_t id, const char *data, int dlen)
+{
+	debug("request %u: sent data len %d", id, dlen);
+	send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
+}
+
+static void
+send_handle(u_int32_t id, int handle)
+{
+	char *string;
+	int hlen;
+
+	handle_to_string(handle, &string, &hlen);
+	debug("request %u: sent handle handle %d", id, handle);
+	send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
+	xfree(string);
+}
+
+static void
+send_names(u_int32_t id, int count, const Stat *stats)
+{
+	Buffer msg;
+	int i;
+
+	buffer_init(&msg);
+	buffer_put_char(&msg, SSH2_FXP_NAME);
+	buffer_put_int(&msg, id);
+	buffer_put_int(&msg, count);
+	debug("request %u: sent names count %d", id, count);
+	for (i = 0; i < count; i++) {
+		buffer_put_cstring(&msg, stats[i].name);
+		buffer_put_cstring(&msg, stats[i].long_name);
+		encode_attrib(&msg, &stats[i].attrib);
+	}
+	send_msg(&msg);
+	buffer_free(&msg);
+}
+
+static void
+send_attrib(u_int32_t id, const Attrib *a)
+{
+	Buffer msg;
+
+	debug("request %u: sent attrib have 0x%x", id, a->flags);
+	buffer_init(&msg);
+	buffer_put_char(&msg, SSH2_FXP_ATTRS);
+	buffer_put_int(&msg, id);
+	encode_attrib(&msg, a);
+	send_msg(&msg);
+	buffer_free(&msg);
+}
+
+/* parse incoming */
+
+static void
+process_init(void)
+{
+	Buffer msg;
+
+	version = get_int();
+	verbose("received client version %d", version);
+	buffer_init(&msg);
+	buffer_put_char(&msg, SSH2_FXP_VERSION);
+	buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
+	send_msg(&msg);
+	buffer_free(&msg);
+}
+
+static void
+process_open(void)
+{
+	u_int32_t id, pflags;
+	Attrib *a;
+	char *name;
+	int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
+
+	id = get_int();
+	name = get_string(NULL);
+	pflags = get_int();		/* portable flags */
+	debug3("request %u: open flags %d", id, pflags);
+	a = get_attrib();
+	flags = flags_from_portable(pflags);
+	mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
+	logit("open \"%s\" flags %s mode 0%o",
+	    name, string_from_portable(pflags), mode);
+	fd = open(name, flags, mode);
+	if (fd < 0) {
+		status = errno_to_portable(errno);
+	} else {
+		handle = handle_new(HANDLE_FILE, name, fd, NULL);
+		if (handle < 0) {
+			close(fd);
+		} else {
+			send_handle(id, handle);
+			status = SSH2_FX_OK;
+		}
+	}
+	if (status != SSH2_FX_OK)
+		send_status(id, status);
+	xfree(name);
+}
+
+static void
+process_close(void)
+{
+	u_int32_t id;
+	int handle, ret, status = SSH2_FX_FAILURE;
+
+	id = get_int();
+	handle = get_handle();
+	debug3("request %u: close handle %u", id, handle);
+	handle_log_close(handle, NULL);
+	ret = handle_close(handle);
+	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	send_status(id, status);
+}
+
+static void
+process_read(void)
+{
+	char buf[64*1024];
+	u_int32_t id, len;
+	int handle, fd, ret, status = SSH2_FX_FAILURE;
+	u_int64_t off;
+
+	id = get_int();
+	handle = get_handle();
+	off = get_int64();
+	len = get_int();
+
+	debug("request %u: read \"%s\" (handle %d) off %llu len %d",
+	    id, handle_to_name(handle), handle, (unsigned long long)off, len);
+	if (len > sizeof buf) {
+		len = sizeof buf;
+		debug2("read change len %d", len);
+	}
+	fd = handle_to_fd(handle);
+	if (fd >= 0) {
+		if (lseek(fd, off, SEEK_SET) < 0) {
+			error("process_read: seek failed");
+			status = errno_to_portable(errno);
+		} else {
+			ret = read(fd, buf, len);
+			if (ret < 0) {
+				status = errno_to_portable(errno);
+			} else if (ret == 0) {
+				status = SSH2_FX_EOF;
+			} else {
+				send_data(id, buf, ret);
+				status = SSH2_FX_OK;
+				handle_update_read(handle, ret);
+			}
+		}
+	}
+	if (status != SSH2_FX_OK)
+		send_status(id, status);
+}
+
+static void
+process_write(void)
+{
+	u_int32_t id;
+	u_int64_t off;
+	u_int len;
+	int handle, fd, ret, status = SSH2_FX_FAILURE;
+	char *data;
+
+	id = get_int();
+	handle = get_handle();
+	off = get_int64();
+	data = get_string(&len);
+
+	debug("request %u: write \"%s\" (handle %d) off %llu len %d",
+	    id, handle_to_name(handle), handle, (unsigned long long)off, len);
+	fd = handle_to_fd(handle);
+	if (fd >= 0) {
+		if (lseek(fd, off, SEEK_SET) < 0) {
+			status = errno_to_portable(errno);
+			error("process_write: seek failed");
+		} else {
+/* XXX ATOMICIO ? */
+			ret = write(fd, data, len);
+			if (ret < 0) {
+				error("process_write: write failed");
+				status = errno_to_portable(errno);
+			} else if ((size_t)ret == len) {
+				status = SSH2_FX_OK;
+				handle_update_write(handle, ret);
+			} else {
+				debug2("nothing at all written");
+			}
+		}
+	}
+	send_status(id, status);
+	xfree(data);
+}
+
+static void
+process_do_stat(int do_lstat)
+{
+	Attrib a;
+	struct stat st;
+	u_int32_t id;
+	char *name;
+	int ret, status = SSH2_FX_FAILURE;
+
+	id = get_int();
+	name = get_string(NULL);
+	debug3("request %u: %sstat", id, do_lstat ? "l" : "");
+	verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
+	ret = do_lstat ? lstat(name, &st) : stat(name, &st);
+	if (ret < 0) {
+		status = errno_to_portable(errno);
+	} else {
+		stat_to_attrib(&st, &a);
+		send_attrib(id, &a);
+		status = SSH2_FX_OK;
+	}
+	if (status != SSH2_FX_OK)
+		send_status(id, status);
+	xfree(name);
+}
+
+static void
+process_stat(void)
+{
+	process_do_stat(0);
+}
+
+static void
+process_lstat(void)
+{
+	process_do_stat(1);
+}
+
+static void
+process_fstat(void)
+{
+	Attrib a;
+	struct stat st;
+	u_int32_t id;
+	int fd, ret, handle, status = SSH2_FX_FAILURE;
+
+	id = get_int();
+	handle = get_handle();
+	debug("request %u: fstat \"%s\" (handle %u)",
+	    id, handle_to_name(handle), handle);
+	fd = handle_to_fd(handle);
+	if (fd  >= 0) {
+		ret = fstat(fd, &st);
+		if (ret < 0) {
+			status = errno_to_portable(errno);
+		} else {
+			stat_to_attrib(&st, &a);
+			send_attrib(id, &a);
+			status = SSH2_FX_OK;
+		}
+	}
+	if (status != SSH2_FX_OK)
+		send_status(id, status);
+}
+
+static struct timeval *
+attrib_to_tv(const Attrib *a)
+{
+	static struct timeval tv[2];
+
+	tv[0].tv_sec = a->atime;
+	tv[0].tv_usec = 0;
+	tv[1].tv_sec = a->mtime;
+	tv[1].tv_usec = 0;
+	return tv;
+}
+
+static void
+process_setstat(void)
+{
+	Attrib *a;
+	u_int32_t id;
+	char *name;
+	int status = SSH2_FX_OK, ret;
+
+	id = get_int();
+	name = get_string(NULL);
+	a = get_attrib();
+	debug("request %u: setstat name \"%s\"", id, name);
+	if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+		logit("set \"%s\" size %llu", name, a->size);
+		ret = truncate(name, a->size);
+		if (ret == -1)
+			status = errno_to_portable(errno);
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+		logit("set \"%s\" mode %04o", name, a->perm);
+		ret = chmod(name, a->perm & 0777);
+		if (ret == -1)
+			status = errno_to_portable(errno);
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+		char buf[64];
+		time_t t = a->mtime;
+
+		strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+		    localtime(&t));
+		logit("set \"%s\" modtime %s", name, buf);
+		ret = utimes(name, attrib_to_tv(a));
+		if (ret == -1)
+			status = errno_to_portable(errno);
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
+		logit("set \"%s\" owner %lu group %lu", name,
+		    (u_long)a->uid, (u_long)a->gid);
+		ret = chown(name, a->uid, a->gid);
+		if (ret == -1)
+			status = errno_to_portable(errno);
+	}
+	send_status(id, status);
+	xfree(name);
+}
+
+static void
+process_fsetstat(void)
+{
+	Attrib *a;
+	u_int32_t id;
+	int handle, fd, ret;
+	int status = SSH2_FX_OK;
+
+	id = get_int();
+	handle = get_handle();
+	a = get_attrib();
+	debug("request %u: fsetstat handle %d", id, handle);
+	fd = handle_to_fd(handle);
+	if (fd < 0) {
+		status = SSH2_FX_FAILURE;
+	} else {
+		char *name = handle_to_name(handle);
+
+		if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+			logit("set \"%s\" size %llu", name, a->size);
+			ret = ftruncate(fd, a->size);
+			if (ret == -1)
+				status = errno_to_portable(errno);
+		}
+		if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+			logit("set \"%s\" mode %04o", name, a->perm);
+#ifdef HAVE_FCHMOD
+			ret = fchmod(fd, a->perm & 0777);
+#else
+			ret = chmod(name, a->perm & 0777);
+#endif
+			if (ret == -1)
+				status = errno_to_portable(errno);
+		}
+		if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+			char buf[64];
+			time_t t = a->mtime;
+
+			strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+			    localtime(&t));
+			logit("set \"%s\" modtime %s", name, buf);
+#ifdef HAVE_FUTIMES
+			ret = futimes(fd, attrib_to_tv(a));
+#else
+			ret = utimes(name, attrib_to_tv(a));
+#endif
+			if (ret == -1)
+				status = errno_to_portable(errno);
+		}
+		if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
+			logit("set \"%s\" owner %lu group %lu", name,
+			    (u_long)a->uid, (u_long)a->gid);
+#ifdef HAVE_FCHOWN
+			ret = fchown(fd, a->uid, a->gid);
+#else
+			ret = chown(name, a->uid, a->gid);
+#endif
+			if (ret == -1)
+				status = errno_to_portable(errno);
+		}
+	}
+	send_status(id, status);
+}
+
+static void
+process_opendir(void)
+{
+	DIR *dirp = NULL;
+	char *path;
+	int handle, status = SSH2_FX_FAILURE;
+	u_int32_t id;
+
+	id = get_int();
+	path = get_string(NULL);
+	debug3("request %u: opendir", id);
+	logit("opendir \"%s\"", path);
+	dirp = opendir(path);
+	if (dirp == NULL) {
+		status = errno_to_portable(errno);
+	} else {
+		handle = handle_new(HANDLE_DIR, path, 0, dirp);
+		if (handle < 0) {
+			closedir(dirp);
+		} else {
+			send_handle(id, handle);
+			status = SSH2_FX_OK;
+		}
+
+	}
+	if (status != SSH2_FX_OK)
+		send_status(id, status);
+	xfree(path);
+}
+
+static void
+process_readdir(void)
+{
+	DIR *dirp;
+	struct dirent *dp;
+	char *path;
+	int handle;
+	u_int32_t id;
+
+	id = get_int();
+	handle = get_handle();
+	debug("request %u: readdir \"%s\" (handle %d)", id,
+	    handle_to_name(handle), handle);
+	dirp = handle_to_dir(handle);
+	path = handle_to_name(handle);
+	if (dirp == NULL || path == NULL) {
+		send_status(id, SSH2_FX_FAILURE);
+	} else {
+		struct stat st;
+		char pathname[MAXPATHLEN];
+		Stat *stats;
+		int nstats = 10, count = 0, i;
+
+		stats = xcalloc(nstats, sizeof(Stat));
+		while ((dp = readdir(dirp)) != NULL) {
+			if (count >= nstats) {
+				nstats *= 2;
+				stats = xrealloc(stats, nstats, sizeof(Stat));
+			}
+/* XXX OVERFLOW ? */
+			snprintf(pathname, sizeof pathname, "%s%s%s", path,
+			    strcmp(path, "/") ? "/" : "", dp->d_name);
+			if (lstat(pathname, &st) < 0)
+				continue;
+			stat_to_attrib(&st, &(stats[count].attrib));
+			stats[count].name = xstrdup(dp->d_name);
+			stats[count].long_name = ls_file(dp->d_name, &st, 0);
+			count++;
+			/* send up to 100 entries in one message */
+			/* XXX check packet size instead */
+			if (count == 100)
+				break;
+		}
+		if (count > 0) {
+			send_names(id, count, stats);
+			for (i = 0; i < count; i++) {
+				xfree(stats[i].name);
+				xfree(stats[i].long_name);
+			}
+		} else {
+			send_status(id, SSH2_FX_EOF);
+		}
+		xfree(stats);
+	}
+}
+
+static void
+process_remove(void)
+{
+	char *name;
+	u_int32_t id;
+	int status = SSH2_FX_FAILURE;
+	int ret;
+
+	id = get_int();
+	name = get_string(NULL);
+	debug3("request %u: remove", id);
+	logit("remove name \"%s\"", name);
+	ret = unlink(name);
+	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	send_status(id, status);
+	xfree(name);
+}
+
+static void
+process_mkdir(void)
+{
+	Attrib *a;
+	u_int32_t id;
+	char *name;
+	int ret, mode, status = SSH2_FX_FAILURE;
+
+	id = get_int();
+	name = get_string(NULL);
+	a = get_attrib();
+	mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
+	    a->perm & 0777 : 0777;
+	debug3("request %u: mkdir", id);
+	logit("mkdir name \"%s\" mode 0%o", name, mode);
+	ret = mkdir(name, mode);
+	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	send_status(id, status);
+	xfree(name);
+}
+
+static void
+process_rmdir(void)
+{
+	u_int32_t id;
+	char *name;
+	int ret, status;
+
+	id = get_int();
+	name = get_string(NULL);
+	debug3("request %u: rmdir", id);
+	logit("rmdir name \"%s\"", name);
+	ret = rmdir(name);
+	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	send_status(id, status);
+	xfree(name);
+}
+
+static void
+process_realpath(void)
+{
+	char resolvedname[MAXPATHLEN];
+	u_int32_t id;
+	char *path;
+
+	id = get_int();
+	path = get_string(NULL);
+	if (path[0] == '\0') {
+		xfree(path);
+		path = xstrdup(".");
+	}
+	debug3("request %u: realpath", id);
+	verbose("realpath \"%s\"", path);
+	if (realpath(path, resolvedname) == NULL) {
+		send_status(id, errno_to_portable(errno));
+	} else {
+		Stat s;
+		attrib_clear(&s.attrib);
+		s.name = s.long_name = resolvedname;
+		send_names(id, 1, &s);
+	}
+	xfree(path);
+}
+
+static void
+process_rename(void)
+{
+	u_int32_t id;
+	char *oldpath, *newpath;
+	int status;
+	struct stat sb;
+
+	id = get_int();
+	oldpath = get_string(NULL);
+	newpath = get_string(NULL);
+	debug3("request %u: rename", id);
+	logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
+	status = SSH2_FX_FAILURE;
+	if (lstat(oldpath, &sb) == -1)
+		status = errno_to_portable(errno);
+	else if (S_ISREG(sb.st_mode)) {
+		/* Race-free rename of regular files */
+		if (link(oldpath, newpath) == -1) {
+			if (errno == EOPNOTSUPP
+#ifdef LINK_OPNOTSUPP_ERRNO
+			    || errno == LINK_OPNOTSUPP_ERRNO
+#endif
+			    ) {
+				struct stat st;
+
+				/*
+				 * fs doesn't support links, so fall back to
+				 * stat+rename.  This is racy.
+				 */
+				if (stat(newpath, &st) == -1) {
+					if (rename(oldpath, newpath) == -1)
+						status =
+						    errno_to_portable(errno);
+					else
+						status = SSH2_FX_OK;
+				}
+			} else {
+				status = errno_to_portable(errno);
+			}
+		} else if (unlink(oldpath) == -1) {
+			status = errno_to_portable(errno);
+			/* clean spare link */
+			unlink(newpath);
+		} else
+			status = SSH2_FX_OK;
+	} else if (stat(newpath, &sb) == -1) {
+		if (rename(oldpath, newpath) == -1)
+			status = errno_to_portable(errno);
+		else
+			status = SSH2_FX_OK;
+	}
+	send_status(id, status);
+	xfree(oldpath);
+	xfree(newpath);
+}
+
+static void
+process_readlink(void)
+{
+	u_int32_t id;
+	int len;
+	char buf[MAXPATHLEN];
+	char *path;
+
+	id = get_int();
+	path = get_string(NULL);
+	debug3("request %u: readlink", id);
+	verbose("readlink \"%s\"", path);
+	if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
+		send_status(id, errno_to_portable(errno));
+	else {
+		Stat s;
+
+		buf[len] = '\0';
+		attrib_clear(&s.attrib);
+		s.name = s.long_name = buf;
+		send_names(id, 1, &s);
+	}
+	xfree(path);
+}
+
+static void
+process_symlink(void)
+{
+	u_int32_t id;
+	char *oldpath, *newpath;
+	int ret, status;
+
+	id = get_int();
+	oldpath = get_string(NULL);
+	newpath = get_string(NULL);
+	debug3("request %u: symlink", id);
+	logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
+	/* this will fail if 'newpath' exists */
+	ret = symlink(oldpath, newpath);
+	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	send_status(id, status);
+	xfree(oldpath);
+	xfree(newpath);
+}
+
+static void
+process_extended(void)
+{
+	u_int32_t id;
+	char *request;
+
+	id = get_int();
+	request = get_string(NULL);
+	send_status(id, SSH2_FX_OP_UNSUPPORTED);		/* MUST */
+	xfree(request);
+}
+
+/* stolen from ssh-agent */
+
+static void
+process(void)
+{
+	u_int msg_len;
+	u_int buf_len;
+	u_int consumed;
+	u_int type;
+	u_char *cp;
+
+	buf_len = buffer_len(&iqueue);
+	if (buf_len < 5)
+		return;		/* Incomplete message. */
+	cp = buffer_ptr(&iqueue);
+	msg_len = get_u32(cp);
+	if (msg_len > SFTP_MAX_MSG_LENGTH) {
+		error("bad message from %s local user %s",
+		    client_addr, pw->pw_name);
+		cleanup_exit(11);
+	}
+	if (buf_len < msg_len + 4)
+		return;
+	buffer_consume(&iqueue, 4);
+	buf_len -= 4;
+	type = buffer_get_char(&iqueue);
+	switch (type) {
+	case SSH2_FXP_INIT:
+		process_init();
+		break;
+	case SSH2_FXP_OPEN:
+		process_open();
+		break;
+	case SSH2_FXP_CLOSE:
+		process_close();
+		break;
+	case SSH2_FXP_READ:
+		process_read();
+		break;
+	case SSH2_FXP_WRITE:
+		process_write();
+		break;
+	case SSH2_FXP_LSTAT:
+		process_lstat();
+		break;
+	case SSH2_FXP_FSTAT:
+		process_fstat();
+		break;
+	case SSH2_FXP_SETSTAT:
+		process_setstat();
+		break;
+	case SSH2_FXP_FSETSTAT:
+		process_fsetstat();
+		break;
+	case SSH2_FXP_OPENDIR:
+		process_opendir();
+		break;
+	case SSH2_FXP_READDIR:
+		process_readdir();
+		break;
+	case SSH2_FXP_REMOVE:
+		process_remove();
+		break;
+	case SSH2_FXP_MKDIR:
+		process_mkdir();
+		break;
+	case SSH2_FXP_RMDIR:
+		process_rmdir();
+		break;
+	case SSH2_FXP_REALPATH:
+		process_realpath();
+		break;
+	case SSH2_FXP_STAT:
+		process_stat();
+		break;
+	case SSH2_FXP_RENAME:
+		process_rename();
+		break;
+	case SSH2_FXP_READLINK:
+		process_readlink();
+		break;
+	case SSH2_FXP_SYMLINK:
+		process_symlink();
+		break;
+	case SSH2_FXP_EXTENDED:
+		process_extended();
+		break;
+	default:
+		error("Unknown message %d", type);
+		break;
+	}
+	/* discard the remaining bytes from the current packet */
+	if (buf_len < buffer_len(&iqueue))
+		fatal("iqueue grew unexpectedly");
+	consumed = buf_len - buffer_len(&iqueue);
+	if (msg_len < consumed)
+		fatal("msg_len %d < consumed %d", msg_len, consumed);
+	if (msg_len > consumed)
+		buffer_consume(&iqueue, msg_len - consumed);
+}
+
+/* Cleanup handler that logs active handles upon normal exit */
+void
+cleanup_exit(int i)
+{
+	if (pw != NULL && client_addr != NULL) {
+		handle_log_exit();
+		logit("session closed for local user %s from [%s]",
+		    pw->pw_name, client_addr);
+	}
+	_exit(i);
+}
+
+static void
+usage(void)
+{
+	extern char *__progname;
+
+	fprintf(stderr,
+	    "usage: %s [-he] [-l log_level] [-f log_facility]\n", __progname);
+	exit(1);
+}
+
+int
+main(int argc, char **argv)
+{
+	fd_set *rset, *wset;
+	int in, out, max, ch, skipargs = 0, log_stderr = 0;
+	ssize_t len, olen, set_size;
+	SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
+	char *cp;
+
+	extern char *optarg;
+	extern char *__progname;
+
+	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+	sanitise_stdfd();
+
+	__progname = ssh_get_progname(argv[0]);
+	log_init(__progname, log_level, log_facility, log_stderr);
+
+	while (!skipargs && (ch = getopt(argc, argv, "C:f:l:che")) != -1) {
+		switch (ch) {
+		case 'c':
+			/*
+			 * Ignore all arguments if we are invoked as a
+			 * shell using "sftp-server -c command"
+			 */
+			skipargs = 1;
+			break;
+		case 'e':
+			log_stderr = 1;
+			break;
+		case 'l':
+			log_level = log_level_number(optarg);
+			if (log_level == SYSLOG_LEVEL_NOT_SET)
+				error("Invalid log level \"%s\"", optarg);
+			break;
+		case 'f':
+			log_facility = log_facility_number(optarg);
+			if (log_level == SYSLOG_FACILITY_NOT_SET)
+				error("Invalid log facility \"%s\"", optarg);
+			break;
+		case 'h':
+		default:
+			usage();
+		}
+	}
+
+	log_init(__progname, log_level, log_facility, log_stderr);
+
+	if ((cp = getenv("SSH_CONNECTION")) != NULL) {
+		client_addr = xstrdup(cp);
+		if ((cp = strchr(client_addr, ' ')) == NULL)
+			fatal("Malformed SSH_CONNECTION variable: \"%s\"",
+			    getenv("SSH_CONNECTION"));
+		*cp = '\0';
+	} else
+		client_addr = xstrdup("UNKNOWN");
+
+	if ((pw = getpwuid(getuid())) == NULL)
+		fatal("No user found for uid %lu", (u_long)getuid());
+	pw = pwcopy(pw);
+
+	logit("session opened for local user %s from [%s]",
+	    pw->pw_name, client_addr);
+
+	handle_init();
+
+	in = dup(STDIN_FILENO);
+	out = dup(STDOUT_FILENO);
+
+#ifdef HAVE_CYGWIN
+	setmode(in, O_BINARY);
+	setmode(out, O_BINARY);
+#endif
+
+	max = 0;
+	if (in > max)
+		max = in;
+	if (out > max)
+		max = out;
+
+	buffer_init(&iqueue);
+	buffer_init(&oqueue);
+
+	set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
+	rset = (fd_set *)xmalloc(set_size);
+	wset = (fd_set *)xmalloc(set_size);
+
+	for (;;) {
+		memset(rset, 0, set_size);
+		memset(wset, 0, set_size);
+
+		FD_SET(in, rset);
+		olen = buffer_len(&oqueue);
+		if (olen > 0)
+			FD_SET(out, wset);
+
+		if (select(max+1, rset, wset, NULL, NULL) < 0) {
+			if (errno == EINTR)
+				continue;
+			error("select: %s", strerror(errno));
+			cleanup_exit(2);
+		}
+
+		/* copy stdin to iqueue */
+		if (FD_ISSET(in, rset)) {
+			char buf[4*4096];
+			len = read(in, buf, sizeof buf);
+			if (len == 0) {
+				debug("read eof");
+				cleanup_exit(0);
+			} else if (len < 0) {
+				error("read: %s", strerror(errno));
+				cleanup_exit(1);
+			} else {
+				buffer_append(&iqueue, buf, len);
+			}
+		}
+		/* send oqueue to stdout */
+		if (FD_ISSET(out, wset)) {
+			len = write(out, buffer_ptr(&oqueue), olen);
+			if (len < 0) {
+				error("write: %s", strerror(errno));
+				cleanup_exit(1);
+			} else {
+				buffer_consume(&oqueue, len);
+			}
+		}
+		/* process requests from client */
+		process();
+	}
+}