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/*
* scp - SSH scp wrapper functions
*
* This file is part of the SSH Library
*
* Copyright (c) 2009 by Aris Adamantiadis <aris@0xbadc0de.be>
*
* 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
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The SSH Library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the SSH Library; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
#include <stdio.h>
#include <string.h>
#include "libssh/priv.h"
#include "libssh/scp.h"
/** @defgroup ssh_scp SSH-scp
* @brief SCP protocol over SSH functions
* @addtogroup ssh_scp
* @{
*/
/** @brief Creates a new scp session
* @param session the SSH session to use
* @param mode one of SSH_SCP_WRITE or SSH_SCP_READ, depending if you need to drop files remotely or read them.
* It is not possible to combine read and write.
* @param location The directory in which write or read will be done. Any push or pull will be relative
* to this place
* @returns NULL if the creation was impossible.
* @returns a ssh_scp handle if it worked.
*/
ssh_scp ssh_scp_new(ssh_session session, int mode, const char *location){
ssh_scp scp=malloc(sizeof(struct ssh_scp_struct));
if(scp == NULL){
ssh_set_error(session,SSH_FATAL,"Error allocating memory for ssh_scp");
return NULL;
}
ZERO_STRUCTP(scp);
if((mode&~SSH_SCP_RECURSIVE) != SSH_SCP_WRITE && (mode &~SSH_SCP_RECURSIVE) != SSH_SCP_READ){
ssh_set_error(session,SSH_FATAL,"Invalid mode %d for ssh_scp_new()",mode);
ssh_scp_free(scp);
return NULL;
}
scp->location=strdup(location);
if (scp->location == NULL) {
ssh_set_error(session,SSH_FATAL,"Error allocating memory for ssh_scp");
ssh_scp_free(scp);
return NULL;
}
scp->session=session;
scp->mode=mode & ~SSH_SCP_RECURSIVE;
scp->recursive = (mode & SSH_SCP_RECURSIVE) != 0;
scp->channel=NULL;
scp->state=SSH_SCP_NEW;
return scp;
}
int ssh_scp_init(ssh_scp scp){
int r;
char execbuffer[1024];
uint8_t code;
if(scp->state != SSH_SCP_NEW){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_init called under invalid state");
return SSH_ERROR;
}
ssh_log(scp->session,SSH_LOG_PROTOCOL,"Initializing scp session %s %son location '%s'",
scp->mode==SSH_SCP_WRITE?"write":"read",
scp->recursive?"recursive ":"",
scp->location);
scp->channel=channel_new(scp->session);
if(scp->channel == NULL){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
r= channel_open_session(scp->channel);
if(r==SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
if(scp->mode == SSH_SCP_WRITE)
snprintf(execbuffer,sizeof(execbuffer),"scp -t %s %s",
scp->recursive ? "-r":"", scp->location);
else
snprintf(execbuffer,sizeof(execbuffer),"scp -f %s %s",
scp->recursive ? "-r":"", scp->location);
if(channel_request_exec(scp->channel,execbuffer) == SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
if(scp->mode == SSH_SCP_WRITE){
r=channel_read(scp->channel,&code,1,0);
if(code != 0){
ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
} else {
channel_write(scp->channel,"",1);
}
if(scp->mode == SSH_SCP_WRITE)
scp->state=SSH_SCP_WRITE_INITED;
else
scp->state=SSH_SCP_READ_INITED;
return SSH_OK;
}
int ssh_scp_close(ssh_scp scp){
char buffer[128];
int err;
if(scp->channel != NULL){
if(channel_send_eof(scp->channel) == SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
/* avoid situations where data are buffered and
* not yet stored on disk. This can happen if the close is sent
* before we got the EOF back
*/
while(!channel_is_eof(scp->channel)){
err=channel_read(scp->channel,buffer,sizeof(buffer),0);
if(err==SSH_ERROR)
break;
}
if(channel_close(scp->channel) == SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
channel_free(scp->channel);
scp->channel=NULL;
}
scp->state=SSH_SCP_NEW;
return SSH_OK;
}
void ssh_scp_free(ssh_scp scp){
if(scp->state != SSH_SCP_NEW)
ssh_scp_close(scp);
if(scp->channel)
channel_free(scp->channel);
SAFE_FREE(scp->location);
SAFE_FREE(scp->request_name);
SAFE_FREE(scp->warning);
SAFE_FREE(scp);
}
/** @brief creates a directory in a scp in sink mode
* @param scp the scp handle.
* @param dirname Name of the directory being created.
* @param mode Unix permissions for the new directory, e.g. 0755.
* @returns SSH_OK if the directory was created.
* @returns SSH_ERROR if an error happened.
* @see ssh_scp_leave_directory
*/
int ssh_scp_push_directory(ssh_scp scp, const char *dirname, int mode){
char buffer[1024];
int r;
uint8_t code;
char *dir;
char *perms;
if(scp->state != SSH_SCP_WRITE_INITED){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_push_directory called under invalid state");
return SSH_ERROR;
}
dir=ssh_basename(dirname);
perms=ssh_scp_string_mode(mode);
snprintf(buffer, sizeof(buffer), "D%s 0 %s\n", perms, dir);
SAFE_FREE(dir);
SAFE_FREE(perms);
r=channel_write(scp->channel,buffer,strlen(buffer));
if(r==SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
r=channel_read(scp->channel,&code,1,0);
if(code != 0){
ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
return SSH_OK;
}
/**
* @brief Leaves a directory
* @returns SSH_OK if the directory was created.
* @returns SSH_ERROR if an error happened.
* @see ssh_scp_push_directory
*/
int ssh_scp_leave_directory(ssh_scp scp){
char buffer[]="E\n";
int r;
uint8_t code;
if(scp->state != SSH_SCP_WRITE_INITED){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_leave_directory called under invalid state");
return SSH_ERROR;
}
r=channel_write(scp->channel,buffer,strlen(buffer));
if(r==SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
r=channel_read(scp->channel,&code,1,0);
if(code != 0){
ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
return SSH_OK;
}
/** @brief initializes the sending of a file to a scp in sink mode
* @param scp the scp handle.
* @param filename Name of the file being sent. It should not contain any path indicator
* @param size Exact size in bytes of the file being sent.
* @param mode Unix permissions for the new file, e.g. 0644
* @returns SSH_OK if the file is ready to be sent.
* @returns SSH_ERROR if an error happened.
*/
int ssh_scp_push_file(ssh_scp scp, const char *filename, size_t size, int mode){
char buffer[1024];
int r;
uint8_t code;
char *file;
char *perms;
if(scp->state != SSH_SCP_WRITE_INITED){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_push_file called under invalid state");
return SSH_ERROR;
}
file=ssh_basename(filename);
perms=ssh_scp_string_mode(mode);
ssh_log(scp->session,SSH_LOG_PROTOCOL,"SCP pushing file %s, size %" PRIdS " with permissions '%s'",file,size,perms);
snprintf(buffer, sizeof(buffer), "C%s %" PRIdS " %s\n", perms, size, file);
SAFE_FREE(file);
SAFE_FREE(perms);
r=channel_write(scp->channel,buffer,strlen(buffer));
if(r==SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
r=channel_read(scp->channel,&code,1,0);
if(code != 0){
ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
scp->filelen = size;
scp->processed = 0;
scp->state=SSH_SCP_WRITE_WRITING;
return SSH_OK;
}
/** @brief waits for a response of the scp server
* @internal
* @param response pointer where the response message must be
* copied if any. This pointer must then be free'd.
* @returns the return code.
* @returns SSH_ERROR a error occured
*/
int ssh_scp_response(ssh_scp scp, char **response){
unsigned char code;
int r;
char msg[128];
r=channel_read(scp->channel,&code,1,0);
if(r == SSH_ERROR)
return SSH_ERROR;
if(code == 0)
return 0;
if(code > 2){
ssh_set_error(scp->session,SSH_FATAL, "SCP: invalid status code %ud received", code);
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
r=ssh_scp_read_string(scp,msg,sizeof(msg));
if(r==SSH_ERROR)
return r;
/* Warning */
if(code == 1){
ssh_set_error(scp->session,SSH_REQUEST_DENIED, "SCP: Warning: status code 1 received: %s", msg);
ssh_log(scp->session,SSH_LOG_RARE,"SCP: Warning: status code 1 received: %s", msg);
if(response)
*response=strdup(msg);
return 1;
}
if(code == 2){
ssh_set_error(scp->session,SSH_FATAL, "SCP: Error: status code 2 received: %s", msg);
if(response)
*response=strdup(msg);
return 2;
}
/* Not reached */
return SSH_ERROR;
}
/** @brief Write into a remote scp file
* @param scp the scp handle.
* @param buffer the buffer to write
* @param len the number of bytes to write
* @returns SSH_OK the write was successful
* @returns SSH_ERROR an error happened while writing
*/
int ssh_scp_write(ssh_scp scp, const void *buffer, size_t len){
int w;
//int r;
//uint8_t code;
if(scp->state != SSH_SCP_WRITE_WRITING){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_write called under invalid state");
return SSH_ERROR;
}
if(scp->processed + len > scp->filelen)
len = scp->filelen - scp->processed;
/* hack to avoid waiting for window change */
channel_poll(scp->channel,0);
w=channel_write(scp->channel,buffer,len);
if(w != SSH_ERROR)
scp->processed += w;
else {
scp->state=SSH_SCP_ERROR;
//return=channel_get_exit_status(scp->channel);
return SSH_ERROR;
}
/* Check if we arrived at end of file */
if(scp->processed == scp->filelen) {
/* r=channel_read(scp->channel,&code,1,0);
if(r==SSH_ERROR){
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
if(code != 0){
ssh_set_error(scp->session,SSH_FATAL, "scp status code %ud not valid", code);
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
*/
scp->processed=scp->filelen=0;
scp->state=SSH_SCP_WRITE_INITED;
}
return SSH_OK;
}
/**
* @brief reads a string on a channel, terminated by '\n'
* @param scp the scp handle.
* @param buffer pointer to a buffer to place the string
* @param len size of the buffer in bytes. If the string is bigger
* than len-1, only len-1 bytes are read and the string
* is null-terminated.
* @returns SSH_OK The string was read
* @returns SSH_ERROR Error happened while reading
*/
int ssh_scp_read_string(ssh_scp scp, char *buffer, size_t len){
size_t r=0;
int err=SSH_OK;
while(r<len-1){
err=channel_read(scp->channel,&buffer[r],1,0);
if(err==SSH_ERROR){
break;
}
if(err==0){
ssh_set_error(scp->session,SSH_FATAL,"End of file while reading string");
err=SSH_ERROR;
break;
}
r++;
if(buffer[r-1] == '\n')
break;
}
buffer[r]=0;
return err;
}
/** @brief waits for a scp request (file, directory)
* @returns SSH_ERROR Some error happened
* @returns SSH_SCP_REQUEST_NEWFILE The other side is sending a file
* @returns SSH_SCP_REQUEST_NEWDIRECTORY The other side is sending a directory
* @returns SSH_SCP_REQUEST_END_DIRECTORY The other side has finished with the current directory
* @see ssh_scp_read
* @see ssh_scp_deny_request
* @see ssh_scp_accept_request
*/
int ssh_scp_pull_request(ssh_scp scp){
char buffer[4096];
char *mode=NULL;
char *p,*tmp;
size_t size;
char *name=NULL;
int err;
if(scp->state != SSH_SCP_READ_INITED){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_pull_request called under invalid state");
return SSH_ERROR;
}
err=ssh_scp_read_string(scp,buffer,sizeof(buffer));
if(err==SSH_ERROR){
if(channel_is_eof(scp->channel)){
scp->state=SSH_SCP_TERMINATED;
return SSH_SCP_REQUEST_EOF;
}
return err;
}
p=strchr(buffer,'\n');
if(p!=NULL)
*p='\0';
ssh_log(scp->session,SSH_LOG_PROTOCOL,"Received SCP request: '%s'",buffer);
switch(buffer[0]){
case 'C':
/* File */
case 'D':
/* Directory */
p=strchr(buffer,' ');
if(p==NULL)
goto error;
*p='\0';
p++;
//mode=strdup(&buffer[1]);
scp->request_mode=ssh_scp_integer_mode(&buffer[1]);
tmp=p;
p=strchr(p,' ');
if(p==NULL)
goto error;
*p=0;
size=strtoull(tmp,NULL,10);
p++;
name=strdup(p);
SAFE_FREE(scp->request_name);
scp->request_name=name;
if(buffer[0]=='C'){
scp->filelen=size;
scp->request_type=SSH_SCP_REQUEST_NEWFILE;
} else {
scp->filelen='0';
scp->request_type=SSH_SCP_REQUEST_NEWDIR;
}
scp->state=SSH_SCP_READ_REQUESTED;
scp->processed = 0;
return scp->request_type;
break;
case 'E':
scp->request_type=SSH_SCP_REQUEST_ENDDIR;
channel_write(scp->channel,"",1);
return scp->request_type;
case 0x1:
ssh_set_error(scp->session,SSH_REQUEST_DENIED,"SCP: Warning: %s",&buffer[1]);
scp->request_type=SSH_SCP_REQUEST_WARNING;
SAFE_FREE(scp->warning);
scp->warning=strdup(&buffer[1]);
return scp->request_type;
case 0x2:
ssh_set_error(scp->session,SSH_FATAL,"SCP: Error: %s",&buffer[1]);
return SSH_ERROR;
case 'T':
/* Timestamp */
default:
ssh_set_error(scp->session,SSH_FATAL,"Unhandled message: (%d)%s",buffer[0],buffer);
return SSH_ERROR;
}
/* a parsing error occured */
error:
SAFE_FREE(name);
SAFE_FREE(mode);
ssh_set_error(scp->session,SSH_FATAL,"Parsing error while parsing message: %s",buffer);
return SSH_ERROR;
}
/**
* @brief denies the transfer of a file or creation of a directory
* coming from the remote party
* @param scp the scp handle.
* @param reason nul-terminated string with a human-readable explanation
* of the deny
* @returns SSH_OK the message was sent
* @returns SSH_ERROR Error sending the message, or sending it in a bad state
*/
int ssh_scp_deny_request(ssh_scp scp, const char *reason){
char buffer[4096];
int err;
if(scp->state != SSH_SCP_READ_REQUESTED){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_deny_request called under invalid state");
return SSH_ERROR;
}
snprintf(buffer,sizeof(buffer),"%c%s\n",2,reason);
err=channel_write(scp->channel,buffer,strlen(buffer));
if(err==SSH_ERROR) {
return SSH_ERROR;
}
else {
scp->state=SSH_SCP_READ_INITED;
return SSH_OK;
}
}
/**
* @brief accepts transfer of a file or creation of a directory
* coming from the remote party
* @param scp the scp handle.
* @returns SSH_OK the message was sent
* @returns SSH_ERROR Error sending the message, or sending it in a bad state
*/
int ssh_scp_accept_request(ssh_scp scp){
char buffer[]={0x00};
int err;
if(scp->state != SSH_SCP_READ_REQUESTED){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_deny_request called under invalid state");
return SSH_ERROR;
}
err=channel_write(scp->channel,buffer,1);
if(err==SSH_ERROR) {
return SSH_ERROR;
}
if(scp->request_type==SSH_SCP_REQUEST_NEWFILE)
scp->state=SSH_SCP_READ_READING;
else
scp->state=SSH_SCP_READ_INITED;
return SSH_OK;
}
/** @brief Read from a remote scp file
* @param scp the scp handle.
* @param buffer Destination buffer
* @param size Size of the buffer
* @returns Number of bytes read
* @returns SSH_ERROR An error happened while reading
*/
int ssh_scp_read(ssh_scp scp, void *buffer, size_t size){
int r;
int code;
if(scp->state == SSH_SCP_READ_REQUESTED && scp->request_type == SSH_SCP_REQUEST_NEWFILE){
r=ssh_scp_accept_request(scp);
if(r==SSH_ERROR)
return r;
}
if(scp->state != SSH_SCP_READ_READING){
ssh_set_error(scp->session,SSH_FATAL,"ssh_scp_read called under invalid state");
return SSH_ERROR;
}
if(scp->processed + size > scp->filelen)
size = scp->filelen - scp->processed;
if(size > 65536)
size=65536; /* avoid too large reads */
r=channel_read(scp->channel,buffer,size,0);
if(r != SSH_ERROR)
scp->processed += r;
else {
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
/* Check if we arrived at end of file */
if(scp->processed == scp->filelen) {
scp->processed=scp->filelen=0;
channel_write(scp->channel,"",1);
code=ssh_scp_response(scp,NULL);
if(code == 0){
scp->state=SSH_SCP_READ_INITED;
return r;
}
if(code==1){
scp->state=SSH_SCP_READ_INITED;
return SSH_ERROR;
}
scp->state=SSH_SCP_ERROR;
return SSH_ERROR;
}
return r;
}
/** @brief Gets the name of the directory or file being
* pushed from the other party
* @returns file name. Should not be freed.
*/
const char *ssh_scp_request_get_filename(ssh_scp scp){
return scp->request_name;
}
/**@brief Gets the permissions of the directory or file being
* pushed from the other party
* @returns Unix permission, e.g 0644.
*/
int ssh_scp_request_get_permissions(ssh_scp scp){
return scp->request_mode;
}
/** @brief Gets the size of the file being pushed
* from the other party
* @returns Numeric size of the file being read.
*/
size_t ssh_scp_request_get_size(ssh_scp scp){
return scp->filelen;
}
/** @brief Converts a scp text mode to an integer one
* @param mode mode to convert, e.g. "0644"
* @returns integer value, e.g. 420 for "0644"
*/
int ssh_scp_integer_mode(const char *mode){
int value=strtoul(mode,NULL,8) & 0xffff;
return value;
}
/** @brief Converts a unix mode into a scp string one.
* @param mode mode to convert, e.g. 420 or 0644
* @returns pointer to a malloc'ed string containing the scp mode,
* e.g. "0644".
*/
char *ssh_scp_string_mode(int mode){
char buffer[16];
snprintf(buffer,sizeof(buffer),"%.4o",mode);
return strdup(buffer);
}
/** @brief Gets the warning string
* @returns Warning string. Should not be freed.
*/
const char *ssh_scp_request_get_warning(ssh_scp scp){
return scp->warning;
}
/** @} */
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