/* buffer.c */
 /* Well, buffers */
 /*
 Copyright 2003 Aris Adamantiadis
 
 This file is part of the SSH Library
 
 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 <stdlib.h>
 #include <string.h>
 #include <netdb.h>
 #include "libssh/priv.h"
 BUFFER *buffer_new(){
     BUFFER *buffer=malloc(sizeof(BUFFER));
     memset(buffer,0,sizeof(BUFFER));
     return buffer;
     }
 
 void buffer_free(BUFFER *buffer){
     if(buffer->data){
         memset(buffer->data,0,buffer->allocated); /* burn the data */
         free(buffer->data);
         }
     free(buffer);
     }
 
 void buffer_reinit(BUFFER *buffer){
     memset(buffer->data,0,buffer->used);
     buffer->used=0;
     buffer->pos=0;
 }
 
 static void realloc_buffer(BUFFER *buffer,int needed){
     needed=(needed+0x7f) & ~0x7f;
     buffer->data=realloc(buffer->data,needed);
     buffer->allocated=needed;
 }
 
 void buffer_add_data(BUFFER *buffer,void *data,int len){
     if(buffer->allocated < buffer->used+len)
         realloc_buffer(buffer,buffer->used+len);
     memcpy(buffer->data+buffer->used,data,len);
     buffer->used+=len;
     }
 
 void buffer_add_ssh_string(BUFFER *buffer,STRING *string){
     u32 len=ntohl(string->size);
     buffer_add_data(buffer,string,len+sizeof(u32));
     }
 
 void buffer_add_u32(BUFFER *buffer,u32 data){
     buffer_add_data(buffer,&data,sizeof(data));
 }
 
 void buffer_add_u64(BUFFER *buffer,u64 data){
     buffer_add_data(buffer,&data,sizeof(data));
 }
 
 void buffer_add_u8(BUFFER *buffer,u8 data){
     buffer_add_data(buffer,&data,sizeof(u8));
 }
 
 void buffer_add_data_begin(BUFFER *buffer, void *data, int len){
     if(buffer->allocated < buffer->used + len)
         realloc_buffer(buffer,buffer->used+len);
     memmove(buffer->data+len,buffer->data,buffer->used);
     memcpy(buffer->data,data,len);
     buffer->used+=len;
 }
 
 void buffer_add_buffer(BUFFER *buffer, BUFFER *source){
     buffer_add_data(buffer,buffer_get(source),buffer_get_len(source));
 }
 
 void *buffer_get(BUFFER *buffer){
     return buffer->data;
 }
 
 void *buffer_get_rest(BUFFER *buffer){
     return buffer->data+buffer->pos;
 }
 
 int buffer_get_len(BUFFER *buffer){
     return buffer->used;
 }
 
 int buffer_get_rest_len(BUFFER *buffer){
     return buffer->used - buffer->pos;
 }
 
 int buffer_pass_bytes(BUFFER *buffer,int len){
     if(buffer->used < buffer->pos+len)
         return 0;
     buffer->pos+=len;
     /* if the buffer is empty after having passed the whole bytes into it, we can clean it */
     if(buffer->pos==buffer->used){
         buffer->pos=0;
         buffer->used=0;
     }
     return len;
 }
 
 int buffer_pass_bytes_end(BUFFER *buffer,int len){
     if(buffer->used < buffer->pos + len)
         return 0;
     buffer->used-=len;
     return len;
 }
 
 int buffer_get_data(BUFFER *buffer, void *data, int len){
     if(buffer->pos+len>buffer->used)
         return 0;  /*no enough data in buffer */
     memcpy(data,buffer->data+buffer->pos,len);
     buffer->pos+=len;
     return len;   /* no yet support for partial reads (is it really needed ?? ) */
 }    
 
 int buffer_get_u8(BUFFER *buffer, u8 *data){
     return buffer_get_data(buffer,data,sizeof(u8));
 }
 
 int buffer_get_u32(BUFFER *buffer, u32 *data){
     return buffer_get_data(buffer,data,sizeof(u32));
 }
 
 int buffer_get_u64(BUFFER *buffer, u64 *data){
     return buffer_get_data(buffer,data,sizeof(u64));
 }
 
 STRING *buffer_get_ssh_string(BUFFER *buffer){
     u32 stringlen;
     u32 hostlen;
     STRING *str;
     if(buffer_get_u32(buffer,&stringlen)==0)
         return NULL;
     hostlen=ntohl(stringlen);
     /* verify if there is enough space in buffer to get it */
     if(buffer->pos+hostlen>buffer->used)
         return 0; /* it is indeed */
     str=string_new(hostlen);
     if(buffer_get_data(buffer,str->string,hostlen)!=hostlen){
         ssh_say(0,"buffer_get_ssh_string: oddish : second test failed when first was successful. len=%d",hostlen);
         free(str);
         return NULL;
         }
     return str;
 }