packet.h

/* Copyright (c) 2014, Robert Escriva
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of this project nor the names of its contributors may
 *       be used to endorse or promote products derived from this software
 *       without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef macaroons_packet_h_
#define macaroons_packet_h_

/* c */
#include <stddef.h>

#define PACKET_PREFIX 4
#define PACKET_SIZE(KEY, VAL) (PACKET_PREFIX + STRLENOF(KEY) + (VAL) + 2)
#define PACKET_MAX_SIZE 65535

#define NULL_PACKET {NULL, 0};
#define EMPTY_PACKET {(const unsigned char*)"0004", 4}

struct packet
{
    const unsigned char* data;
    size_t size;
};

const unsigned char*
parse_packet(const unsigned char* ptr,
             const unsigned char* const end,
             struct packet* pkt);

/* 0 if equal; !0 if non-equal; no other comparison implied */
int
packet_cmp(const struct packet* lhs,
           const struct packet* rhs);

/* A key-value packet has this form:
 * <4 byte header><key><space><value><new-line>
 */
unsigned char*
create_kv_packet(const unsigned char* key, size_t key_sz,
                 const unsigned char* val, size_t val_sz,
                 struct packet* pkt, unsigned char* ptr);
int
parse_kv_packet(const struct packet* pkt,
                const unsigned char** key, size_t* key_sz,
                const unsigned char** val, size_t* val_sz);

/* copy a packet to the memory pointed to by ptr */
unsigned char*
copy_packet(const struct packet* from,
            struct packet* to,
            unsigned char* ptr);
unsigned char*
serialize_packet(const struct packet* from,
                 unsigned char* ptr);
char*
inspect_packet(const struct packet* from, char* ptr);
int
copy_if_parses(const unsigned char** rptr,
               const unsigned char* const end,
               int (*f)(const struct packet* pkt,
                        const unsigned char** s, size_t* s_sz),
               struct packet* to,
               unsigned char** wptr);

/* create a location packet */
unsigned char*
create_location_packet(const unsigned char* location, size_t location_sz,
                       struct packet* pkt, unsigned char* ptr);
int
parse_location_packet(const struct packet* pkt,
                      const unsigned char** location, size_t* location_sz);

/* create a identifier packet */
unsigned char*
create_identifier_packet(const unsigned char* identifier, size_t identifier_sz,
                         struct packet* pkt, unsigned char* ptr);
int
parse_identifier_packet(const struct packet* pkt,
                        const unsigned char** identifier, size_t* identifier_sz);

/* create a signature packet */
unsigned char*
create_signature_packet(const unsigned char* signature,
                        struct packet* pkt, unsigned char* ptr);
int
parse_signature_packet(const struct packet* pkt,
                       const unsigned char** signature);

/* caveat packets */
unsigned char*
create_cid_packet(const unsigned char* cid, size_t cid_sz,
                  struct packet* pkt, unsigned char* ptr);
int
parse_cid_packet(const struct packet* pkt,
                 const unsigned char** cid, size_t* cid_sz);

unsigned char*
create_vid_packet(const unsigned char* vid, size_t vid_sz,
                  struct packet* pkt, unsigned char* ptr);
int
parse_vid_packet(const struct packet* pkt,
                 const unsigned char** vid, size_t* vid_sz);

unsigned char*
create_cl_packet(const unsigned char* cl, size_t cl_sz,
                 struct packet* pkt, unsigned char* ptr);
int
parse_cl_packet(const struct packet* pkt,
                const unsigned char** cl, size_t* cl_sz);

#endif /* macaroons_packet_h_ */