strongswan/src/charon/encoding/payloads/sa_payload.c

398 lines
11 KiB
C

/**
* @file sa_payload.c
*
* @brief Implementation of sa_payload_t.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, Martin Willi
* Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program 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 General Public License
* for more details.
*/
#include <stddef.h>
#include "sa_payload.h"
#include <encoding/payloads/encodings.h>
#include <utils/linked_list.h>
typedef struct private_sa_payload_t private_sa_payload_t;
/**
* Private data of an sa_payload_t object.
*
*/
struct private_sa_payload_t {
/**
* Public sa_payload_t interface.
*/
sa_payload_t public;
/**
* Next payload type.
*/
u_int8_t next_payload;
/**
* Critical flag.
*/
bool critical;
/**
* Length of this payload.
*/
u_int16_t payload_length;
/**
* Proposals in this payload are stored in a linked_list_t.
*/
linked_list_t * proposals;
/**
* @brief Computes the length of this payload.
*
* @param this calling private_sa_payload_t object
*/
void (*compute_length) (private_sa_payload_t *this);
};
/**
* Encoding rules to parse or generate a IKEv2-SA Payload
*
* The defined offsets are the positions in a object of type
* private_sa_payload_t.
*
*/
encoding_rule_t sa_payload_encodings[] = {
/* 1 Byte next payload type, stored in the field next_payload */
{ U_INT_8, offsetof(private_sa_payload_t, next_payload) },
/* the critical bit */
{ FLAG, offsetof(private_sa_payload_t, critical) },
/* 7 Bit reserved bits, nowhere stored */
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
/* Length of the whole SA payload*/
{ PAYLOAD_LENGTH, offsetof(private_sa_payload_t, payload_length) },
/* Proposals are stored in a proposal substructure,
offset points to a linked_list_t pointer */
{ PROPOSALS, offsetof(private_sa_payload_t, proposals) }
};
/*
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! !
~ <Proposals> ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/**
* Implementation of payload_t.verify.
*/
static status_t verify(private_sa_payload_t *this)
{
int proposal_number = 1;
status_t status = SUCCESS;
iterator_t *iterator;
bool first = TRUE;
/* check proposal numbering */
iterator = this->proposals->create_iterator(this->proposals,TRUE);
while(iterator->has_next(iterator))
{
proposal_substructure_t *current_proposal;
iterator->current(iterator,(void **)&current_proposal);
if (current_proposal->get_proposal_number(current_proposal) > proposal_number)
{
if (first)
{
/* first number must be 1 */
status = FAILED;
break;
}
if (current_proposal->get_proposal_number(current_proposal) != (proposal_number + 1))
{
/* must be only one more then previous proposal */
status = FAILED;
break;
}
}
else if (current_proposal->get_proposal_number(current_proposal) < proposal_number)
{
/* must not be smaller then proceeding one */
status = FAILED;
break;
}
status = current_proposal->payload_interface.verify(&(current_proposal->payload_interface));
if (status != SUCCESS)
{
break;
}
first = FALSE;
}
iterator->destroy(iterator);
return status;
}
/**
* Implementation of payload_t.destroy and sa_payload_t.destroy.
*/
static status_t destroy(private_sa_payload_t *this)
{
/* all proposals are getting destroyed */
while (this->proposals->get_count(this->proposals) > 0)
{
proposal_substructure_t *current_proposal;
this->proposals->remove_last(this->proposals,(void **)&current_proposal);
current_proposal->destroy(current_proposal);
}
this->proposals->destroy(this->proposals);
free(this);
return SUCCESS;
}
/**
* Implementation of payload_t.get_encoding_rules.
*/
static void get_encoding_rules(private_sa_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
{
*rules = sa_payload_encodings;
*rule_count = sizeof(sa_payload_encodings) / sizeof(encoding_rule_t);
}
/**
* Implementation of payload_t.get_type.
*/
static payload_type_t get_type(private_sa_payload_t *this)
{
return SECURITY_ASSOCIATION;
}
/**
* Implementation of payload_t.get_next_type.
*/
static payload_type_t get_next_type(private_sa_payload_t *this)
{
return (this->next_payload);
}
/**
* Implementation of payload_t.set_next_type.
*/
static void set_next_type(private_sa_payload_t *this,payload_type_t type)
{
this->next_payload = type;
}
/**
* Implementation of payload_t.get_length.
*/
static size_t get_length(private_sa_payload_t *this)
{
this->compute_length(this);
return this->payload_length;
}
/**
* Implementation of sa_payload_t.create_proposal_substructure_iterator.
*/
static iterator_t *create_proposal_substructure_iterator (private_sa_payload_t *this,bool forward)
{
return this->proposals->create_iterator(this->proposals,forward);
}
/**
* Implementation of sa_payload_t.add_proposal_substructure.
*/
static void add_proposal_substructure(private_sa_payload_t *this,proposal_substructure_t *proposal)
{
status_t status;
u_int proposal_count = this->proposals->get_count(this->proposals);
if (proposal_count > 0)
{
proposal_substructure_t *last_proposal;
status = this->proposals->get_last(this->proposals,(void **) &last_proposal);
/* last transform is now not anymore last one */
last_proposal->set_is_last_proposal(last_proposal, FALSE);
}
proposal->set_is_last_proposal(proposal, TRUE);
proposal->set_proposal_number(proposal, proposal_count + 1);
this->proposals->insert_last(this->proposals,(void *) proposal);
this->compute_length(this);
}
/**
* Implementation of sa_payload_t.add_proposal.
*/
static void add_proposal(private_sa_payload_t *this, proposal_t *proposal)
{
proposal_substructure_t *substructure;
substructure = proposal_substructure_create_from_proposal(proposal);
add_proposal_substructure(this, substructure);
}
/**
* Implementation of sa_payload_t.get_proposals.
*/
static linked_list_t *get_proposals(private_sa_payload_t *this)
{
int struct_number = 0;
int ignore_struct_number = 0;
iterator_t *iterator;
linked_list_t *proposal_list;
/* this list will hold our proposals */
proposal_list = linked_list_create();
/* we do not support proposals split up to two proposal substructures, as
* AH+ESP bundles are not supported in RFC4301 anymore.
* To handle such structures safely, we just skip proposals with multiple
* protocols.
*/
iterator = this->proposals->create_iterator(this->proposals, TRUE);
while (iterator->has_next(iterator))
{
proposal_t *proposal;
proposal_substructure_t *proposal_struct;
iterator->current(iterator, (void **)&proposal_struct);
/* check if a proposal has a single protocol */
if (proposal_struct->get_proposal_number(proposal_struct) == struct_number)
{
if (ignore_struct_number < struct_number)
{
/* remova an already added, if first of series */
proposal_list->remove_last(proposal_list, (void**)proposal);
proposal->destroy(proposal);
ignore_struct_number = struct_number;
}
continue;
}
struct_number++;
proposal = proposal_struct->get_proposal(proposal_struct);
if (proposal)
{
proposal_list->insert_last(proposal_list, proposal);
}
}
iterator->destroy(iterator);
return proposal_list;
}
/**
* Implementation of private_sa_payload_t.compute_length.
*/
static void compute_length (private_sa_payload_t *this)
{
iterator_t *iterator;
size_t length = SA_PAYLOAD_HEADER_LENGTH;
iterator = this->proposals->create_iterator(this->proposals,TRUE);
while (iterator->has_next(iterator))
{
payload_t *current_proposal;
iterator->current(iterator,(void **) &current_proposal);
length += current_proposal->get_length(current_proposal);
}
iterator->destroy(iterator);
this->payload_length = length;
}
/*
* Described in header.
*/
sa_payload_t *sa_payload_create()
{
private_sa_payload_t *this = malloc_thing(private_sa_payload_t);
/* public interface */
this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type;
this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
/* public functions */
this->public.create_proposal_substructure_iterator = (iterator_t* (*) (sa_payload_t *,bool)) create_proposal_substructure_iterator;
this->public.add_proposal_substructure = (void (*) (sa_payload_t *,proposal_substructure_t *)) add_proposal_substructure;
this->public.add_proposal = (void (*) (sa_payload_t*,proposal_t*))add_proposal;
this->public.get_proposals = (linked_list_t* (*) (sa_payload_t *)) get_proposals;
this->public.destroy = (void (*) (sa_payload_t *)) destroy;
/* private functions */
this->compute_length = compute_length;
/* set default values of the fields */
this->critical = FALSE;
this->next_payload = NO_PAYLOAD;
this->payload_length = SA_PAYLOAD_HEADER_LENGTH;
this->proposals = linked_list_create();
return &this->public;
}
/*
* Described in header.
*/
sa_payload_t *sa_payload_create_from_proposal_list(linked_list_t *proposals)
{
iterator_t *iterator;
proposal_t *proposal;
sa_payload_t *sa_payload = sa_payload_create();
/* add every payload from the list */
iterator = proposals->create_iterator(proposals, TRUE);
while (iterator->has_next(iterator))
{
iterator->current(iterator, (void**)&proposal);
add_proposal((private_sa_payload_t*)sa_payload, proposal);
}
iterator->destroy(iterator);
return sa_payload;
}
/*
* Described in header.
*/
sa_payload_t *sa_payload_create_from_proposal(proposal_t *proposal)
{
sa_payload_t *sa_payload = sa_payload_create();
add_proposal((private_sa_payload_t*)sa_payload, proposal);
return sa_payload;
}