c_generic.h

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/*
 * 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.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef C_GENERIC_H
#define C_GENERIC_H

#include <netinet/ip.h>
#include <string.h>

#include "rohc_comp.h"
#include "comp_list.h"


#define IPID_MAX_DELTA  20

#define MAX_ITEM 15

#define L 5

struct ipv4_header_info
{
        struct c_wlsb *ip_id_window;

        struct iphdr old_ip;

        int df_count;
        int rnd_count;
        int nbo_count;

        int rnd;
        int nbo;
        int old_rnd;
        int old_nbo;

        int id_delta;
};


struct ipv6_header_info
{
        struct ip6_hdr old_ip;
        struct list_comp * ext_comp;
};


struct ip_header_info
{
        ip_version  version;           

        int tos_count;
        int ttl_count;
        int protocol_count;

        union
        {
                struct ipv4_header_info v4; 
                struct ipv6_header_info v6; 
        } info;                        
};


struct generic_tmp_variables
{
        int nr_of_ip_hdr;

        unsigned short changed_fields;
        unsigned short changed_fields2;
        int send_static;
        int send_dynamic;

        int nr_sn_bits;
        int nr_ip_id_bits;
        int nr_ip_id_bits2;

        int packet_type;

        int max_size;
};


struct c_generic_context
{
        unsigned int sn;
        struct c_wlsb *sn_window;

        int ir_count;
        int fo_count;
        int so_count;

        int go_back_fo_count;
        int go_back_ir_count;
        int ir_dyn_count;

        struct ip_header_info ip_flags;
        struct ip_header_info ip2_flags;
        int is_ip2_initialized;

        struct generic_tmp_variables tmp_variables;

        /* below are some information and handlers to manage the next header
         * (if any) located just after the IP headers (1 or 2 IP headers) */

        unsigned int next_header_proto;
        unsigned int next_header_len;

        void (*decide_state)(struct c_context *context);

        void (*init_at_IR)(struct c_context *context,
                           const unsigned char *next_header);

        int (*code_static_part)(struct c_context *context,
                                const unsigned char *next_header,
                                unsigned char *dest, int counter);

        int (*code_dynamic_part)(struct c_context *context,
                                 const unsigned char *next_header,
                                 unsigned char *dest, int counter);

        int (*code_UO_packet_head)(struct c_context *context,
                                   const unsigned char *next_header,
                                   unsigned char *dest, int counter,
                                   int *first_position);

        int (*code_UO_packet_tail)(struct c_context *context,
                                   const unsigned char *next_header,
                                   unsigned char *dest, int counter);

        unsigned int (*compute_crc_static)(const unsigned char *ip,
                                           const unsigned char *ip2,
                                           const unsigned char *next_header,
                                           unsigned int crc_type,
                                           unsigned int init_val);

        unsigned int (*compute_crc_dynamic)(const unsigned char *ip,
                                            const unsigned char *ip2,
                                            const unsigned char *next_header,
                                            unsigned int crc_type,
                                            unsigned int init_val);

        void *specific;
};

struct list_comp
{
        struct c_list * ref_list;
        struct c_list * curr_list;
        int counter;
        struct item  based_table[MAX_ITEM];
        struct c_translation  trans_table[MAX_ITEM];
        int update_done;
        int list_compress;
        int islist;
        unsigned char *(*get_extension)(const struct ip_packet ip,int index);

        int (*get_index_table)(const struct ip_packet ip, int index);

        int (*get_size)(unsigned char * ext);

        int (*compare)(unsigned char * ext,struct list_comp * comp,int size, int index_table);

        void (*create_item)(unsigned char *ext, int index_table, int size, 
                                struct list_comp * comp);
        void (*free_table)(struct list_comp * comp);
};
                                                                                                                                                                                                            

/*
 * Function prototypes.
 */

int c_generic_create(struct c_context *context, const struct ip_packet ip);
void c_generic_destroy(struct c_context *context);

void change_mode(struct c_context *context, rohc_mode new_mode);
void change_state(struct c_context *context, rohc_c_state new_state);

void ip6_c_init_table(struct list_comp * comp);
int c_algo_list_compress(struct list_comp * comp, const struct ip_packet ip);
int c_create_current_list(int index, struct list_comp * comp, unsigned char * ext, int index_table);
int decide_type(struct list_comp * comp);
int encode_list(struct list_comp * comp, unsigned char * dest, int counter, int ps, int size);
int encode_type_0(struct list_comp * comp, unsigned char * dest, int counter, int ps);
int encode_type_1(struct list_comp * comp, unsigned char * dest, int counter, int ps);
int encode_type_3(struct list_comp * comp, unsigned char * dest, int counter, int ps);
int encode_type_2(struct list_comp * comp, unsigned char * dest, int counter, int ps);
int c_generic_encode(struct c_context *context,
                     const struct ip_packet ip,
                     int packet_size,
                     unsigned char *dest,
                     int dest_size,
                     int *payload_offset);

void c_generic_feedback(struct c_context *context, struct c_feedback *feedback);

void decide_state(struct c_context *context);


#endif