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/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */
#include "or.h"
static cell_t *new_create_cell(uint16_t aci, unsigned char length, unsigned char *buf)
{
cell_t *c = NULL;
int retval;
if ((aci) && (buf) && (length <= CELL_PAYLOAD_SIZE)) /* valid parameters */
{
c = (cell_t *)malloc(sizeof(cell_t));
if (!c) /* malloc() error */
return NULL;
c->command = CELL_CREATE;
c->aci = aci;
c->length = length;
c->seq = 0;
memcpy((void *)c->payload, (void *)buf, length);
retval = crypto_pseudo_rand(CELL_PAYLOAD_SIZE-length, (unsigned char *)(c->payload+length));
if (retval) /* RAND_pseudo_bytes() error */
{
free((void *)c);
return NULL;
} /* RAND_pseudo_bytes() error */
return c;
} /* valid parameters */
else /* invalid parameters */
return NULL;
}
int pack_create(uint16_t aci, unsigned char *onion, uint32_t onionlen, unsigned char **cellbuf, unsigned int *cellbuflen)
{
cell_t *c;
unsigned char *buf;
unsigned int buflen;
unsigned int cells;
unsigned int dataleft;
unsigned int i;
assert(aci && onion && onionlen && cellbuf && cellbuflen);
/* copy the onion into a buffer, prepend with onion length */
buflen = onionlen+4;
buf = (unsigned char *)malloc(buflen);
if (!buf) /* malloc() error */
return -1;
log(LOG_DEBUG,"pack_create() : Setting onion length to %u.",onionlen);
*(uint32_t*)buf = htonl(onionlen);
memcpy((void *)(buf+4),(void *)onion,onionlen);
/* calculate number of cells required */
if (buflen%CELL_PAYLOAD_SIZE == 0)
cells = buflen/CELL_PAYLOAD_SIZE;
else
cells = buflen/CELL_PAYLOAD_SIZE+1;
/* allocate memory for the cells */
*cellbuflen = cells * sizeof(cell_t);
*cellbuf = malloc(*cellbuflen);
if (!*cellbuf) /* malloc() error */
return -1;
log(LOG_DEBUG,"pack_create() : Allocated memory for %u cells.",cells);
/* create cells one by one */
dataleft = buflen;
for(i=0; i<cells; i++)
{
log(LOG_DEBUG,"pack_create() : Packing %u bytes of data.",dataleft);
if (dataleft >= CELL_PAYLOAD_SIZE)
{
c = new_create_cell(aci,CELL_PAYLOAD_SIZE,buf+i*CELL_PAYLOAD_SIZE);
dataleft -= CELL_PAYLOAD_SIZE;
}
else
c = new_create_cell(aci,dataleft,buf+i*CELL_PAYLOAD_SIZE);
if (!c) /* cell creation failed */
{
free((void *)*cellbuf);
return -1;
} /* cell creation failed */
log(LOG_DEBUG,"pack_create() : new_create_cell succeeded; copying the cell into output buffer");
/* cell has been created, now copy into buffer */
memcpy((void *)(*cellbuf+i*sizeof(cell_t)),(void *)c,sizeof(cell_t));
free((void *)c);
}
free(buf);
return 0;
}
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