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sftpserver: Move duplicate code handling SFTP operations to library

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These can be replaced by user-provided functions when needed.

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
This commit is contained in:
Jakub Jelen
2023-01-23 09:57:43 +01:00
parent af60e23081
commit 5ea54c8159
6 changed files with 1028 additions and 1989 deletions
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932
src/sftpserver.c
View File

@@ -3,7 +3,8 @@
*
* This file is part of the SSH Library
*
* Copyright (c) 2005 by Aris Adamantiadis
* Copyright (c) 2005 Aris Adamantiadis
* Copyright (c) 2022 Zeyu Sheng <shengzeyu19_98@163.com>
*
* The SSH Library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
@@ -23,16 +24,23 @@
#include "config.h"
#include <stdio.h>
#ifndef _WIN32
#include <netinet/in.h>
#include <arpa/inet.h>
#include <dirent.h>
#include <sys/statvfs.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <time.h>
#include "libssh/libssh.h"
#include "libssh/sftp.h"
#include "libssh/sftp_priv.h"
#include "libssh/sftpserver.h"
#include "libssh/ssh2.h"
#include "libssh/priv.h"
#include "libssh/buffer.h"
@@ -40,6 +48,9 @@
#define SFTP_HANDLES 256
#define MAX_ENTRIES_NUM_IN_PACKET 50
#define MAX_LONG_NAME_LEN 350
static sftp_client_message
sftp_make_client_message(sftp_session sftp, sftp_packet packet)
{
@@ -641,3 +652,920 @@ void sftp_handle_remove(sftp_session sftp, void *handle) {
}
}
}
/* Default SFTP handlers */
static const char *
ssh_str_error(int u_errno)
{
switch (u_errno)
{
case SSH_FX_NO_SUCH_FILE:
return "No such file";
case SSH_FX_PERMISSION_DENIED:
return "Permission denied";
case SSH_FX_BAD_MESSAGE:
return "Bad message";
case SSH_FX_OP_UNSUPPORTED:
return "Operation not supported";
default:
return "Operation failed";
}
return "Operation failed";
}
static int
unix_errno_to_ssh_stat(int u_errno)
{
int ret = SSH_OK;
switch (u_errno) {
case 0:
break;
case ENOENT:
case ENOTDIR:
case EBADF:
case ELOOP:
ret = SSH_FX_NO_SUCH_FILE;
break;
case EPERM:
case EACCES:
case EFAULT:
ret = SSH_FX_PERMISSION_DENIED;
break;
case ENAMETOOLONG:
case EINVAL:
ret = SSH_FX_BAD_MESSAGE;
break;
case ENOSYS:
ret = SSH_FX_OP_UNSUPPORTED;
break;
default:
ret = SSH_FX_FAILURE;
break;
}
return ret;
}
static void
stat_to_filexfer_attrib(const struct stat *z_st, struct sftp_attributes_struct *z_attr)
{
z_attr->flags = 0 | (uint32_t)SSH_FILEXFER_ATTR_SIZE;
z_attr->size = z_st->st_size;
z_attr->flags |= (uint32_t)SSH_FILEXFER_ATTR_UIDGID;
z_attr->uid = z_st->st_uid;
z_attr->gid = z_st->st_gid;
z_attr->flags |= (uint32_t)SSH_FILEXFER_ATTR_PERMISSIONS;
z_attr->permissions = z_st->st_mode;
z_attr->flags |= (uint32_t)SSH_FILEXFER_ATTR_ACMODTIME;
z_attr->atime = z_st->st_atime;
z_attr->mtime = z_st->st_mtime;
}
static void
clear_filexfer_attrib(struct sftp_attributes_struct *z_attr)
{
z_attr->flags = 0;
z_attr->size = 0;
z_attr->uid = 0;
z_attr->gid = 0;
z_attr->permissions = 0;
z_attr->atime = 0;
z_attr->mtime = 0;
}
#ifndef _WIN32
/* internal */
enum sftp_handle_type
{
SFTP_NULL_HANDLE,
SFTP_DIR_HANDLE,
SFTP_FILE_HANDLE
};
struct sftp_handle
{
enum sftp_handle_type type;
int fd;
DIR *dirp;
char *name;
};
SSH_SFTP_CALLBACK(process_unsupposed);
SSH_SFTP_CALLBACK(process_open);
SSH_SFTP_CALLBACK(process_read);
SSH_SFTP_CALLBACK(process_write);
SSH_SFTP_CALLBACK(process_close);
SSH_SFTP_CALLBACK(process_opendir);
SSH_SFTP_CALLBACK(process_readdir);
SSH_SFTP_CALLBACK(process_rmdir);
SSH_SFTP_CALLBACK(process_mkdir);
SSH_SFTP_CALLBACK(process_lstat);
SSH_SFTP_CALLBACK(process_readlink);
SSH_SFTP_CALLBACK(process_symlink);
SSH_SFTP_CALLBACK(process_remove);
SSH_SFTP_CALLBACK(process_extended_statvfs);
const struct sftp_message_handler message_handlers[] = {
{"open", NULL, SSH_FXP_OPEN, process_open},
{"close", NULL, SSH_FXP_CLOSE, process_close},
{"read", NULL, SSH_FXP_READ, process_read},
{"write", NULL, SSH_FXP_WRITE, process_write},
{"lstat", NULL, SSH_FXP_LSTAT, process_lstat},
{"fstat", NULL, SSH_FXP_FSTAT, process_unsupposed},
{"setstat", NULL, SSH_FXP_SETSTAT, process_unsupposed},
{"fsetstat", NULL, SSH_FXP_FSETSTAT, process_unsupposed},
{"opendir", NULL, SSH_FXP_OPENDIR, process_opendir},
{"readdir", NULL, SSH_FXP_READDIR, process_readdir},
{"remove", NULL, SSH_FXP_REMOVE, process_remove},
{"mkdir", NULL, SSH_FXP_MKDIR, process_mkdir},
{"rmdir", NULL, SSH_FXP_RMDIR, process_rmdir},
{"realpath", NULL, SSH_FXP_REALPATH, process_unsupposed},
{"stat", NULL, SSH_FXP_STAT, process_unsupposed},
{"rename", NULL, SSH_FXP_RENAME, process_unsupposed},
{"readlink", NULL, SSH_FXP_READLINK, process_readlink},
{"symlink", NULL, SSH_FXP_SYMLINK, process_symlink},
{"init", NULL, SSH_FXP_INIT, sftp_process_init_packet},
{NULL, NULL, 0, NULL},
};
const struct sftp_message_handler extended_handlers[] = {
/* here are some extended type handlers */
{"statvfs", "statvfs@openssh.com", 0, process_extended_statvfs},
{NULL, NULL, 0, NULL},
};
static int
process_open(sftp_client_message client_msg)
{
const char *filename = sftp_client_message_get_filename(client_msg);
uint32_t msg_flag = sftp_client_message_get_flags(client_msg);
ssh_string handle_s = NULL;
struct sftp_handle *h = NULL;
int file_flag;
int fd = -1;
int status;
if (((msg_flag & (uint32_t)SSH_FXF_READ) == SSH_FXF_READ) &&
((msg_flag & (uint32_t)SSH_FXF_WRITE) == SSH_FXF_WRITE)) {
file_flag = O_RDWR; // file must exist
if ((msg_flag & (uint32_t)SSH_FXF_CREAT) == SSH_FXF_CREAT)
file_flag |= O_CREAT;
} else if ((msg_flag & (uint32_t)SSH_FXF_WRITE) == SSH_FXF_WRITE) {
file_flag = O_WRONLY;
if ((msg_flag & (uint32_t)SSH_FXF_APPEND) == SSH_FXF_APPEND)
file_flag |= O_APPEND;
if ((msg_flag & (uint32_t)SSH_FXF_CREAT) == SSH_FXF_CREAT)
file_flag |= O_CREAT;
} else if ((msg_flag & (uint32_t)SSH_FXF_READ) == SSH_FXF_READ) {
file_flag = O_RDONLY;
} else {
SSH_LOG(SSH_LOG_PROTOCOL, "undefined message flag: %d", errno);
sftp_reply_status(client_msg, SSH_FX_FAILURE, "Flag error");
return SSH_ERROR;
}
fd = open(filename, file_flag, 0600);
if (fd == -1) {
status = unix_errno_to_ssh_stat(errno);
SSH_LOG(SSH_LOG_PROTOCOL, "error open file with error: %d", errno);
sftp_reply_status(client_msg, status, "Write error");
return SSH_ERROR;
}
h = calloc(1, sizeof (struct sftp_handle));
if (h == NULL) {
SSH_LOG(SSH_LOG_PROTOCOL, "failed to allocate a new handle");
sftp_reply_status(client_msg, SSH_FX_FAILURE,
"Failed to allocate new handle");
return SSH_ERROR;
}
h->fd = fd;
h->type = SFTP_FILE_HANDLE;
handle_s = sftp_handle_alloc(client_msg->sftp, h);
if (handle_s != NULL) {
sftp_reply_handle(client_msg, handle_s);
ssh_string_free(handle_s);
} else {
SSH_LOG(SSH_LOG_PROTOCOL, "opening file failed: %d", errno);
close(fd);
sftp_reply_status(client_msg, SSH_FX_FAILURE, "No handle available");
}
return SSH_OK;
}
static int
process_read(sftp_client_message client_msg)
{
sftp_session sftp = client_msg->sftp;
ssh_string handle = client_msg->handle;
struct sftp_handle *h = NULL;
uint32_t readn;
int fd = -1;
char *buffer = NULL;
int rv;
h = sftp_handle(sftp, handle);
if (h->type == SFTP_FILE_HANDLE) {
fd = h->fd;
}
if (fd < 0) {
sftp_reply_status(client_msg, SSH_FX_INVALID_HANDLE, NULL);
SSH_LOG(SSH_LOG_PROTOCOL, "error reading file fd: %d", fd);
return SSH_ERROR;
}
rv = lseek(fd, client_msg->offset, SEEK_SET);
if (rv == -1) {
sftp_reply_status(client_msg, SSH_FX_FAILURE, NULL);
SSH_LOG(SSH_LOG_PROTOCOL,
"error seeking file fd: %d at offset: %" PRIu64,
fd,
client_msg->offset);
return SSH_ERROR;
}
buffer = malloc(client_msg->len);
readn = read(fd, buffer, client_msg->len);
if (readn > 0) {
sftp_reply_data(client_msg, buffer, readn);
} else if (readn == 0) {
sftp_reply_status(client_msg, SSH_FX_EOF, "EOF encountered");
} else {
sftp_reply_status(client_msg, SSH_FX_FAILURE, NULL);
SSH_LOG(SSH_LOG_PROTOCOL, "read file error!");
free(buffer);
return SSH_ERROR;
}
free(buffer);
return SSH_OK;
}
static int
process_write(sftp_client_message client_msg)
{
sftp_session sftp = client_msg->sftp;
ssh_string handle = client_msg->handle;
struct sftp_handle *h = NULL;
int written;
int fd = -1;
const char *msg_data = NULL;
uint32_t len;
int rv;
h = sftp_handle(sftp, handle);
if (h->type == SFTP_FILE_HANDLE) {
fd = h->fd;
}
if (fd < 0) {
sftp_reply_status(client_msg, SSH_FX_INVALID_HANDLE, NULL);
SSH_LOG(SSH_LOG_PROTOCOL, "write file fd error!");
return SSH_ERROR;
}
msg_data = ssh_string_get_char(client_msg->data);
len = ssh_string_len(client_msg->data);
rv = lseek(fd, client_msg->offset, SEEK_SET);
if (rv == -1) {
sftp_reply_status(client_msg, SSH_FX_FAILURE, NULL);
SSH_LOG(SSH_LOG_PROTOCOL, "error seeking file at offset: %" PRIu64,
client_msg->offset);
}
written = write(fd, msg_data, len);
if (written == (int)len) {
sftp_reply_status(client_msg, SSH_FX_OK, NULL);
} else if (written == -1) {
sftp_reply_status(client_msg, SSH_FX_FAILURE, "Write error");
} else {
sftp_reply_status(client_msg, SSH_FX_FAILURE, "Partial write");
}
return SSH_OK;
}
static int
process_close(sftp_client_message client_msg)
{
sftp_session sftp = client_msg->sftp;
ssh_string handle = client_msg->handle;
struct sftp_handle *h = NULL;
int ret;
h = sftp_handle(sftp, handle);
if (h->type == SFTP_FILE_HANDLE) {
int fd = h->fd;
close(fd);
ret = SSH_OK;
} else if (h->type == SFTP_DIR_HANDLE) {
DIR *dir = h->dirp;
closedir(dir);
ret = SSH_OK;
} else {
ret = SSH_ERROR;
}
SAFE_FREE(h->name);
sftp_handle_remove(sftp, h);
SAFE_FREE(h);
if (ret == SSH_OK) {
sftp_reply_status(client_msg, SSH_FX_OK, NULL);
} else {
SSH_LOG(SSH_LOG_PROTOCOL, "closing file failed");
sftp_reply_status(client_msg, SSH_FX_BAD_MESSAGE, "Invalid handle");
}
return SSH_OK;
}
static int
process_opendir(sftp_client_message client_msg)
{
DIR *dir = NULL;
const char *dir_name = sftp_client_message_get_filename(client_msg);
ssh_string handle_s = NULL;
struct sftp_handle *h = NULL;
dir = opendir(dir_name);
if (dir == NULL) {
sftp_reply_status(client_msg, SSH_FX_NO_SUCH_FILE, "No such directory");
return SSH_ERROR;
}
h = calloc(1, sizeof (struct sftp_handle));
if (h == NULL) {
SSH_LOG(SSH_LOG_PROTOCOL, "failed to allocate a new handle");
sftp_reply_status(client_msg, SSH_FX_FAILURE,
"Failed to allocate new handle");
return SSH_ERROR;
}
h->dirp = dir;
h->name = strdup(dir_name);
h->type = SFTP_DIR_HANDLE;
handle_s = sftp_handle_alloc(client_msg->sftp, h);
if (handle_s != NULL) {
sftp_reply_handle(client_msg, handle_s);
ssh_string_free(handle_s);
} else {
closedir(dir);
sftp_reply_status(client_msg, SSH_FX_FAILURE, "No handle available");
}
return SSH_OK;
}
static int
readdir_long_name(char *z_file_name, struct stat *z_st, char *z_long_name)
{
char tmpbuf[MAX_LONG_NAME_LEN];
char time[50];
char *ptr = z_long_name;
int mode = z_st->st_mode;
*ptr = '\0';
switch (mode & S_IFMT) {
case S_IFDIR:
*ptr++ = 'd';
break;
default:
*ptr++ = '-';
break;
}
/* user */
if (mode & 0400)
*ptr++ = 'r';
else
*ptr++ = '-';
if (mode & 0200)
*ptr++ = 'w';
else
*ptr++ = '-';
if (mode & 0100) {
if (mode & S_ISUID)
*ptr++ = 's';
else
*ptr++ = 'x';
} else
*ptr++ = '-';
/* group */
if (mode & 040)
*ptr++ = 'r';
else
*ptr++ = '-';
if (mode & 020)
*ptr++ = 'w';
else
*ptr++ = '-';
if (mode & 010)
*ptr++ = 'x';
else
*ptr++ = '-';
/* other */
if (mode & 04)
*ptr++ = 'r';
else
*ptr++ = '-';
if (mode & 02)
*ptr++ = 'w';
else
*ptr++ = '-';
if (mode & 01)
*ptr++ = 'x';
else
*ptr++ = '-';
*ptr++ = ' ';
*ptr = '\0';
snprintf(tmpbuf, sizeof(tmpbuf), "%3d %d %d %d", (int)z_st->st_nlink,
(int)z_st->st_uid, (int)z_st->st_gid, (int)z_st->st_size);
strcat(z_long_name, tmpbuf);
ctime_r(&z_st->st_mtime, time);
if ((ptr = strchr(time, '\n'))) {
*ptr = '\0';
}
snprintf(tmpbuf, sizeof(tmpbuf), " %s %s", time + 4, z_file_name);
strcat(z_long_name, tmpbuf);
return SSH_OK;
}
static int
process_readdir(sftp_client_message client_msg)
{
sftp_session sftp = client_msg->sftp;
ssh_string handle = client_msg->handle;
struct sftp_handle *h = NULL;
int ret = SSH_OK;
int entries = 0;
struct dirent *dentry = NULL;
DIR *dir = NULL;
char long_path[PATH_MAX];
int srclen;
const char *handle_name = NULL;
h = sftp_handle(sftp, client_msg->handle);
if (h->type == SFTP_DIR_HANDLE) {
dir = h->dirp;
handle_name = h->name;
}
if (dir == NULL) {
sftp_reply_status(client_msg, SSH_FX_INVALID_HANDLE, NULL);
SSH_LOG(SSH_LOG_PROTOCOL, "read dir handle error!");
return SSH_ERROR;
}
if (handle_name == NULL) {
sftp_reply_status(client_msg, SSH_FX_INVALID_HANDLE, NULL);
return SSH_ERROR;
}
srclen = strlen(handle_name);
if (srclen + 2 >= PATH_MAX) {
SSH_LOG(SSH_LOG_PROTOCOL, "handle string length exceed max length!");
sftp_reply_status(client_msg, SSH_FX_INVALID_HANDLE, NULL);
return SSH_ERROR;
}
for (int i = 0; i < MAX_ENTRIES_NUM_IN_PACKET; i++) {
dentry = readdir(dir);
if (dentry != NULL) {
struct sftp_attributes_struct attr;
struct stat st;
char long_name[MAX_LONG_NAME_LEN];
if (strlen(dentry->d_name) + srclen + 1 >= PATH_MAX) {
SSH_LOG(SSH_LOG_PROTOCOL,
"handle string length exceed max length!");
sftp_reply_status(client_msg, SSH_FX_INVALID_HANDLE, NULL);
return SSH_ERROR;
}
snprintf(long_path, PATH_MAX, "%s/%s", handle_name, dentry->d_name);
if (lstat(long_path, &st) == 0) {
stat_to_filexfer_attrib(&st, &attr);
} else {
clear_filexfer_attrib(&attr);
}
if (readdir_long_name(dentry->d_name, &st, long_name) == 0) {
sftp_reply_names_add(client_msg, dentry->d_name, long_name, &attr);
} else {
printf("readdir long name error\n");
}
entries++;
} else {
break;
}
}
if (entries > 0) {
ret = sftp_reply_names(client_msg);
} else {
sftp_reply_status(client_msg, SSH_FX_EOF, NULL);
}
return ret;
}
static int
process_mkdir(sftp_client_message client_msg)
{
int ret = SSH_OK;
const char *filename = sftp_client_message_get_filename(client_msg);
uint32_t msg_flags = client_msg->flags;
uint32_t permission = client_msg->attr->permissions;
uint32_t mode = (msg_flags & (uint32_t)SSH_FILEXFER_ATTR_PERMISSIONS)
? permission & (uint32_t)07777 : 0777;
int status = SSH_FX_OK;
int rv;
if (filename == NULL) {
sftp_reply_status(client_msg, SSH_FX_NO_SUCH_FILE, "File name error");
return SSH_ERROR;
}
rv = mkdir(filename, mode);
if (rv < 0) {
status = unix_errno_to_ssh_stat(errno);
ret = SSH_ERROR;
}
sftp_reply_status(client_msg, status, NULL);
return ret;
}
static int
process_rmdir(sftp_client_message client_msg)
{
int ret = SSH_OK;
const char *filename = sftp_client_message_get_filename(client_msg);
int status = SSH_FX_OK;
int rv;
if (filename == NULL) {
sftp_reply_status(client_msg, SSH_FX_NO_SUCH_FILE, "File name error");
return SSH_ERROR;
}
rv = rmdir(filename);
if (rv < 0) {
status = unix_errno_to_ssh_stat(errno);
ret = SSH_ERROR;
}
sftp_reply_status(client_msg, status, NULL);
return ret;
}
static int
process_lstat(sftp_client_message client_msg)
{
int ret = SSH_OK;
const char *filename = sftp_client_message_get_filename(client_msg);
struct sftp_attributes_struct attr;
struct stat st;
int status = SSH_FX_OK;
int rv;
if (filename == NULL) {
sftp_reply_status(client_msg, SSH_FX_NO_SUCH_FILE, "File name error");
return SSH_ERROR;
}
rv = lstat(filename, &st);
if (rv < 0) {
status = unix_errno_to_ssh_stat(errno);
sftp_reply_status(client_msg, status, NULL);
ret = SSH_ERROR;
} else {
stat_to_filexfer_attrib(&st, &attr);
sftp_reply_attr(client_msg, &attr);
}
return ret;
}
static int
process_readlink(sftp_client_message client_msg)
{
int ret = SSH_OK;
const char *filename = sftp_client_message_get_filename(client_msg);
char buf[PATH_MAX];
int len = -1;
const char *err_msg;
int status = SSH_FX_OK;
if (filename == NULL) {
sftp_reply_status(client_msg, SSH_FX_NO_SUCH_FILE, "File name error");
return SSH_ERROR;
}
len = readlink(filename, buf, sizeof(buf) - 1);
if (len < 0) {
SSH_LOG(SSH_LOG_PROTOCOL, "read link error with reason: %d", errno);
status = unix_errno_to_ssh_stat(errno);
err_msg = ssh_str_error(status);
sftp_reply_status(client_msg, status, err_msg);
ret = SSH_ERROR;
} else {
buf[len] = '\0';
sftp_reply_name(client_msg, buf, NULL);
}
return ret;
}
static int
process_symlink(sftp_client_message client_msg)
{
int ret = SSH_OK;
const char *destpath = sftp_client_message_get_filename(client_msg);
const char *srcpath = ssh_string_get_char(client_msg->data);
int status = SSH_FX_OK;
int rv;
SSH_LOG(SSH_LOG_PROTOCOL, "try to create link with src: %s and dest: %s",
srcpath, destpath);
if (srcpath == NULL || destpath == NULL) {
sftp_reply_status(client_msg, SSH_FX_NO_SUCH_FILE, "File name error");
return SSH_ERROR;
}
rv = symlink(srcpath, destpath);
if (rv < 0) {
status = unix_errno_to_ssh_stat(errno);
SSH_LOG(SSH_LOG_PROTOCOL, "error symlink with error: %d", errno);
sftp_reply_status(client_msg, status, "Write error");
ret = SSH_ERROR;
} else {
sftp_reply_status(client_msg, SSH_FX_OK, "write success");
}
return ret;
}
static int
process_remove(sftp_client_message client_msg)
{
int ret = SSH_OK;
const char *filename = sftp_client_message_get_filename(client_msg);
int rv;
int status = SSH_FX_OK;
rv = unlink(filename);
if (rv < 0) {
SSH_LOG(SSH_LOG_PROTOCOL, "unlink error with reason: %d", errno);
status = unix_errno_to_ssh_stat(errno);
ret = SSH_ERROR;
}
sftp_reply_status(client_msg, status, NULL);
return ret;
}
static int
process_unsupposed(sftp_client_message client_msg)
{
sftp_reply_status(client_msg, SSH_FX_OP_UNSUPPORTED,
"Operation not supported");
SSH_LOG(SSH_LOG_PROTOCOL, "Message type %d not implemented",
sftp_client_message_get_type(client_msg));
return SSH_OK;
}
static int
process_extended_statvfs(sftp_client_message client_msg)
{
const char *path = sftp_client_message_get_filename(client_msg);
struct statvfs st;
int status;
int rv;
rv = statvfs(path, &st);
if (rv == 0) {
sftp_statvfs_t sftp_statvfs;
u_int64_t flag;
sftp_statvfs = calloc(1, sizeof(struct sftp_statvfs_struct));
if (sftp_statvfs != NULL) {
flag = (st.f_flag & ST_RDONLY) ? SSH_FXE_STATVFS_ST_RDONLY : 0;
flag |= (st.f_flag & ST_NOSUID) ? SSH_FXE_STATVFS_ST_NOSUID : 0;
sftp_statvfs->f_bsize = st.f_bsize;
sftp_statvfs->f_frsize = st.f_frsize;
sftp_statvfs->f_blocks = st.f_blocks;
sftp_statvfs->f_bfree = st.f_bfree;
sftp_statvfs->f_bavail = st.f_bavail;
sftp_statvfs->f_files = st.f_files;
sftp_statvfs->f_ffree = st.f_ffree;
sftp_statvfs->f_favail = st.f_favail;
sftp_statvfs->f_fsid = st.f_fsid;
sftp_statvfs->f_flag = flag;
sftp_statvfs->f_namemax = st.f_namemax;
rv = sftp_reply_statvfs(client_msg, sftp_statvfs);
free(sftp_statvfs);
if (rv == 0) {
return SSH_OK;
}
}
}
status = unix_errno_to_ssh_stat(errno);
sftp_reply_status(client_msg, status, NULL);
printf("statvfs send failed!\n");
return SSH_ERROR;
}
static int
process_extended(sftp_client_message sftp_msg)
{
int status = SSH_ERROR;
const char *subtype = sftp_msg->submessage;
sftp_server_message_callback handler = NULL;
for (int i = 0; extended_handlers[i].cb != NULL; i++) {
if (strcmp(subtype, extended_handlers[i].extended_name) == 0) {
handler = extended_handlers[i].cb;
break;
}
}
if (handler != NULL) {
status = handler(sftp_msg);
return status;
}
sftp_reply_status(sftp_msg, SSH_FX_OP_UNSUPPORTED,
"Extended Operation not supported");
SSH_LOG(SSH_LOG_PROTOCOL, "Extended Message type %s not implemented",
subtype);
return SSH_OK;
}
static int
dispatch_sftp_request(sftp_client_message sftp_msg)
{
int status = SSH_ERROR;
sftp_server_message_callback handler = NULL;
uint8_t type = sftp_client_message_get_type(sftp_msg);
for (int i = 0; message_handlers[i].cb != NULL; i++) {
if (type == message_handlers[i].type) {
handler = message_handlers[i].cb;
break;
}
}
if (handler != NULL) {
status = handler(sftp_msg);
} else {
sftp_reply_status(sftp_msg, SSH_FX_OP_UNSUPPORTED,
"Operation not supported");
SSH_LOG(SSH_LOG_PROTOCOL, "Message type %u not implemented", type);
return SSH_OK;
}
return status;
}
static int
process_client_message(sftp_client_message client_msg)
{
int status = SSH_OK;
if (client_msg == NULL) {
return SSH_ERROR;
}
switch (client_msg->type) {
case SSH_FXP_EXTENDED:
status = process_extended(client_msg);
break;
default:
status = dispatch_sftp_request(client_msg);
}
if (status != SSH_OK)
SSH_LOG(SSH_LOG_PROTOCOL, "error occur in process client message!");
return status;
}
/**
* @brief Default subsystem request handler for SFTP subsystem
*
* @param[in] session The ssh session
* @param[in] channel The existing ssh channel
* @param[in] subsystem The subsystem name. Only "sftp" is handled
* @param[out] userdata The pointer to sftp_session which will get the
* resulting SFTP session
*
* @return SSH_OK when the SFTP server was successfully initialized, SSH_ERROR
* otherwise.
*/
int
sftp_channel_default_subsystem_request(ssh_session session,
ssh_channel channel,
const char *subsystem,
void *userdata)
{
if (strcmp(subsystem, "sftp") == 0) {
sftp_session *sftp = (sftp_session *)userdata;
/* initialize sftp session and file handler */
*sftp = sftp_server_new(session, channel);
if (*sftp == NULL) {
return SSH_ERROR;
}
return SSH_OK;
}
return SSH_ERROR;
}
/**
* @brief Default data callback for sftp server
*
* @param[in] session The ssh session
* @param[in] channel The ssh channel with SFTP session opened
* @param[in] data The data to be processed.
* @param[in] len The length of input data to be processed
* @param[in] is_stderr Unused channel flag for stderr flagging
* @param[in] userdata The pointer to sftp_session
*
* @return number of bytes processed, -1 when error occurs.
*/
int
sftp_channel_default_data_callback(UNUSED_PARAM(ssh_session session),
UNUSED_PARAM(ssh_channel channel),
void *data,
UNUSED_PARAM(uint32_t len),
UNUSED_PARAM(int is_stderr),
void *userdata)
{
sftp_session *sftpp = (sftp_session *)userdata;
sftp_session sftp = NULL;
sftp_client_message msg;
int decode_len;
int rc;
if (sftpp == NULL) {
SSH_LOG(SSH_LOG_WARNING, "NULL userdata passed to callback");
return -1;
}
sftp = *sftpp;
decode_len = sftp_decode_channel_data_to_packet(sftp, data);
if (decode_len == -1)
return -1;
msg = sftp_get_client_message_from_packet(sftp);
rc = process_client_message(msg);
sftp_client_message_free(msg);
if (rc != SSH_OK)
SSH_LOG(SSH_LOG_PROTOCOL, "process sftp failed!");
return decode_len;
}
#else
/* Not available on Windows for now */
int
sftp_channel_default_data_callback(UNUSED_PARAM(ssh_session session),
UNUSED_PARAM(ssh_channel channel),
UNUSED_PARAM(void *data),
UNUSED_PARAM(uint32_t len),
UNUSED_PARAM(int is_stderr),
UNUSED_PARAM(void *userdata))
{
return -1;
}
int
sftp_channel_default_subsystem_request(UNUSED_PARAM(ssh_session session),
UNUSED_PARAM(ssh_channel channel),
UNUSED_PARAM(const char *subsystem),
UNUSED_PARAM(void *userdata))
{
return SSH_ERROR;
}
#endif