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355 lines
8.7 KiB
C
355 lines
8.7 KiB
C
/**
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* cell.c
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* Cell manipulation.
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*
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* Matej Pfajfar <mp292@cam.ac.uk>
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*/
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/*
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* Changes :
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* $Log$
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* Revision 1.1 2002/06/26 22:45:50 arma
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* Initial revision
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*
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* Revision 1.16 2002/06/14 20:41:19 mp292
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* Parameter checking error - thanks Roger.
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*
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* Revision 1.15 2002/04/02 14:27:11 badbytes
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* Final finishes.
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*
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* Revision 1.14 2002/04/02 10:19:37 badbytes
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* Stricter parameter checking.
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*
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* Revision 1.13 2002/03/12 23:30:19 mp292
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* Removed some memory overruns.
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*
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* Revision 1.12 2002/03/03 00:06:45 mp292
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* Modifications to support re-transmission.
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*
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* Revision 1.11 2002/02/03 22:41:45 mp292
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* Changes to cell size.
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*
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* Revision 1.10 2002/01/21 20:57:19 mp292
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* Reviewed according to Secure-Programs-HOWTO.
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*
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* Revision 1.9 2002/01/17 15:00:43 mp292
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* Fixed a bug which caused malloc() generate a seg fault.
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*
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* Revision 1.8 2002/01/16 23:01:54 mp292
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* First phase of system testing completed (main functionality).
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*
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* Revision 1.7 2002/01/14 13:05:37 badbytes
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* System testing in progress.
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*
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* Revision 1.6 2002/01/10 13:15:54 badbytes
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* Fixed ACI size from 32bits to 16bits.
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*
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* Revision 1.5 2002/01/07 13:06:06 badbytes
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* cell.ACI is now cell.aci
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*
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* Revision 1.4 2002/01/07 09:26:00 badbytes
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* Added pack_create() and pack_data().
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*
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* Revision 1.3 2002/01/07 07:48:34 badbytes
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* fixed new_create_cell()
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*
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* Revision 1.2 2002/01/04 12:11:54 badbytes
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* Syntax errors fixed.
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*
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* Revision 1.1 2002/01/04 12:08:34 badbytes
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* Added functions for cell creation.
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*
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <netinet/in.h>
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#include <openssl/rand.h>
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#include "cell.h"
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#include "log.h"
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cell_t *new_padding_cell()
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{
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cell_t *c = NULL;
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int retval;
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c = malloc(sizeof(cell_t));
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if (!c) /* malloc() error */
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return NULL;
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retval = RAND_pseudo_bytes((unsigned char *)c,sizeof(cell_t));
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if (retval == -1) /* RAND_pseudo_bytes() error */
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{
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free((void *)c);
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return NULL;
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} /* RAND_pseudo_bytes() error */
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c->command = CELL_PADDING;
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return c;
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}
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cell_t *new_destroy_cell(uint16_t aci)
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{
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cell_t *c = NULL;
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int retval;
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if (aci) /* valid ACI */
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{
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c = (cell_t *)malloc(sizeof(cell_t));
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if (!c) /* malloc error */
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return NULL;
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retval = RAND_pseudo_bytes((unsigned char *)c+3,sizeof(cell_t)-3);
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if (retval == -1) /* RAND_pseudo_bytes() error */
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{
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free((void *)c);
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return NULL;
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} /* RAND_pseudo_bytes() error */
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c->aci = aci;
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c->command = CELL_DESTROY;
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return c;
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} /* valid ACI */
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else /* invalid ACI */
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return NULL;
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}
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cell_t *new_ack_cell(uint16_t aci)
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{
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cell_t *c = NULL;
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int retval;
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if (aci) /* valid ACI */
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{
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c = (cell_t *)malloc(sizeof(cell_t));
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if (!c) /* malloc error */
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return NULL;
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retval = RAND_pseudo_bytes((unsigned char *)c+3,sizeof(cell_t)-3);
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if (retval == -1) /* RAND_pseudo_bytes() error */
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{
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free((void *)c);
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return NULL;
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} /* RAND_pseudo_bytes() error */
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c->aci = aci;
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c->command = CELL_ACK;
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return c;
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} /* valid ACI */
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else /* invalid ACI */
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return NULL;
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}
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cell_t *new_nack_cell(uint16_t aci)
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{
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cell_t *c = NULL;
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int retval;
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if (aci) /* valid ACI */
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{
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c = (cell_t *)malloc(sizeof(cell_t));
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if (!c) /* malloc error */
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return NULL;
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retval = RAND_pseudo_bytes((unsigned char *)c+3,sizeof(cell_t)-3);
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if (retval == -1) /* RAND_pseudo_bytes() error */
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{
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free((void *)c);
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return NULL;
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} /* RAND_pseudo_bytes() error */
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c->aci = aci;
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c->command = CELL_NACK;
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return c;
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} /* valid ACI */
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else /* invalid ACI */
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return NULL;
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}
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cell_t *new_create_cell(uint16_t aci, unsigned char length, unsigned char *buf)
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{
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cell_t *c = NULL;
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int retval;
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if ((aci) && (buf) && (length <= CELL_PAYLOAD_SIZE)) /* valid parameters */
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{
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c = (cell_t *)malloc(sizeof(cell_t));
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if (!c) /* malloc() error */
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return NULL;
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c->command = CELL_CREATE;
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c->aci = aci;
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c->length = length;
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c->seq = 0;
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memcpy((void *)c->payload, (void *)buf, length);
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retval = RAND_pseudo_bytes((unsigned char *)(c->payload+length),CELL_PAYLOAD_SIZE-length);
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if (retval == -1) /* RAND_pseudo_bytes() error */
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{
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free((void *)c);
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return NULL;
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} /* RAND_pseudo_bytes() error */
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return c;
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} /* valid parameters */
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else /* invalid parameters */
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return NULL;
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}
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cell_t *new_data_cell(uint16_t aci, unsigned char length, unsigned char *buf)
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{
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cell_t *c = NULL;
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int retval;
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if ((aci) && (buf) && (length <= CELL_PAYLOAD_SIZE)) /* valid parameters */
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{
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c = malloc(sizeof(cell_t));
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if (!c) /* malloc() error */
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return NULL;
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c->command = CELL_DATA;
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c->aci = aci;
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c->length = length;
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c->seq = 0;
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memcpy((void *)c->payload, (void *)buf, length);
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retval = RAND_pseudo_bytes((unsigned char *)(c->payload+length),CELL_PAYLOAD_SIZE-length);
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if (retval == -1) /* RAND_pseudo_bytes() error */
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{
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free((void *)c);
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return NULL;
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} /* RAND_pseudo_bytes() error */
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return c;
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} /* valid parameters */
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else /* invalid parameters */
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return NULL;
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}
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int pack_create(uint16_t aci, unsigned char *onion, uint32_t onionlen, unsigned char **cellbuf, unsigned int *cellbuflen)
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{
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cell_t *c;
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unsigned char *buf;
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unsigned int buflen;
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unsigned int cells;
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unsigned int dataleft;
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unsigned int i;
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if ((aci) && (onion) && (cellbuf) && (cellbuflen) && (onionlen)) /* valid parameters */
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{
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/* copy the onion into a buffer, prepend with onion length */
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buflen = onionlen+4;
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buf = (unsigned char *)malloc(buflen);
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if (!buf) /* malloc() error */
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return -1;
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log(LOG_DEBUG,"pack_create() : Setting onion length to %u.",onionlen);
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onionlen=htonl(onionlen);
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memcpy((void *)buf,(void *)&onionlen,4);
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onionlen=ntohl(onionlen);
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memcpy((void *)(buf+4),(void *)onion,onionlen);
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/* calculate number of cells required */
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if (buflen%CELL_PAYLOAD_SIZE == 0)
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cells = buflen/CELL_PAYLOAD_SIZE;
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else
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cells = buflen/CELL_PAYLOAD_SIZE+1;
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/* allocate memory for the cells */
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*cellbuflen = cells * sizeof(cell_t);
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*cellbuf = malloc(*cellbuflen);
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if (!*cellbuf) /* malloc() error */
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return -1;
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log(LOG_DEBUG,"pack_create() : Allocated memory for %u cells.",cells);
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/* create cells one by one */
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dataleft = buflen;
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for(i=0; i<cells; i++)
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{
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log(LOG_DEBUG,"pack_create() : Packing %u bytes of data.",dataleft);
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if (dataleft >= CELL_PAYLOAD_SIZE)
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{
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c = new_create_cell(aci,CELL_PAYLOAD_SIZE,buf+i*CELL_PAYLOAD_SIZE);
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dataleft -= CELL_PAYLOAD_SIZE;
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}
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else
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c = new_create_cell(aci,dataleft,buf+i*CELL_PAYLOAD_SIZE);
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if (!c) /* cell creation failed */
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{
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free((void *)*cellbuf);
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return -1;
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} /* cell creation failed */
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log(LOG_DEBUG,"pack_create() : new_create_cell succeeded; copying the cell into output buffer");
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/* cell has been created, now copy into buffer */
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memcpy((void *)(*cellbuf+i*sizeof(cell_t)),(void *)c,sizeof(cell_t));
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free((void *)c);
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}
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free(buf);
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return 0;
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} /* valid parameters */
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else /* invalid parameters */
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return -1;
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}
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int pack_data(uint16_t aci,unsigned char *buf, size_t buflen, unsigned char **cellbuf, unsigned int *cellbuflen)
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{
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cell_t *c;
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unsigned int cells;
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unsigned int dataleft;
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unsigned int i;
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if ((aci) && (buf) && (cellbuf) && (cellbuflen) && (buflen)) /* valid parameters */
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{
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/* calculate number of cells required */
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if (buflen%CELL_PAYLOAD_SIZE == 0)
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cells = buflen/CELL_PAYLOAD_SIZE;
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else
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cells = buflen/CELL_PAYLOAD_SIZE+1;
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/* allocate memory for the cells */
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*cellbuf = malloc(cells * sizeof(cell_t));
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if (!*cellbuf) /* malloc() error */
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return -1;
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log(LOG_DEBUG,"pack_data() : Allocated memory for %u cells.",cells);
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/* create cells one by one */
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dataleft = buflen;
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for(i=0; i<cells; i++)
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{
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log(LOG_DEBUG,"pack_data() : Packing %u bytes of data.",dataleft);
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if (dataleft >= CELL_PAYLOAD_SIZE)
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{
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c = new_data_cell(aci,CELL_PAYLOAD_SIZE,buf+i*CELL_PAYLOAD_SIZE);
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dataleft -= CELL_PAYLOAD_SIZE;
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}
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else
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c = new_data_cell(aci,dataleft,buf+i*CELL_PAYLOAD_SIZE);
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if (!c) /* cell creation failed */
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{
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free((void *)*cellbuf);
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return -1;
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} /* cell creation failed */
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/* cell has been created, now copy into buffer */
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memcpy((void *)(*cellbuf+i*sizeof(cell_t)),(void *)c,sizeof(cell_t));
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free((void *)c);
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}
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*cellbuflen = cells * sizeof(cell_t);
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return 0;
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} /* valid parameters */
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else /* invalid parameters */
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return -1;
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}
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