src/rohc/comp.c

/*
    ROHC Project 2003 at Lulea University of Technology, Sweden.
    Authors: Andreas Vernersson <andver-8@student.luth.se>
             Daniel Pettersson <danpet-7@student.luth.se>
             Erik Soderstrom <soderstrom@yahoo.com>
             Fredrik Lindstrom <frelin-9@student.luth.se>
             Johan Stenmark <johste-8@student.luth.se>
             Martin Juhlin <juhlin@users.sourceforge.net>
             Mikael Larsson <larmik-9@student.luth.se>
             Robert Maxe <robmax-1@student.luth.se>
             
    Copyright (C) 2003 Andreas Vernersson, Daniel Pettersson, 
    Erik Soderström, Fredrik Lindström, Johan Stenmark, 
    Martin Juhlin, Mikael Larsson, Robert Maxe.  

    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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/    
/***************************************************************************
 * File:        comp.c                                                     *
 * Description: description                                                *
 ***************************************************************************/

#include "rohc.h"
#include "comp.h"
#include "c_util.h"

#include "decomp.h"
#include "d_util.h"

///////////////////////////////////////////////////////////////////////
// Profile definitions and variables

// Profile IDs
#define ROHC_PROFILE_UNCOMPRESSED     0
#define ROHC_PROFILE_UDP     2
#define ROHC_PROFILE_UDPLITE 8
#define ROHC_PROFILE_IP      4

// The profiles.. in c_ip.c, c_udp.c, c_udp_lite.c, c_uncompressed.c
extern struct sc_profile c_ip_profile;
extern struct sc_profile c_uncompressed_profile;
extern struct sc_profile c_udp_profile;
extern struct sc_profile c_udp_lite_profile;

/* C_NUM_PROFILES is defined in comp.h */

// Pointers to all profiles:
static struct sc_profile *c_profiles[C_NUM_PROFILES] = {
        &c_udp_profile,
        &c_udp_lite_profile,
        &c_ip_profile,
        &c_uncompressed_profile
};

////////////////////////////////////////////////////////////////////////
// Feedback variables
static void c_piggyback_destroy(struct sc_rohc *);
static int c_piggyback_get(struct sc_rohc *, unsigned char *buf);

////////////////////////////////////////////////////////////////////////
// Context definitions functions
static void c_destroy_contexts(struct sc_rohc *);
static int c_create_contexts(struct sc_rohc *);
static int c_alloc_contexts(struct sc_rohc *, int num);


////////////////////////////////////////////////////////////////////////
// Public functions

/* Allocate space for a compressor (transmit side) */
void *rohc_alloc_compressor(int max_cid)
{

        struct sc_rohc *comp;
        int i;
        rohc_debugf(1, "ROHC: Allocating compressor\n");

        comp = kmalloc(sizeof(struct sc_rohc), GFP_ATOMIC);
        if (comp == NULL) {
          rohc_debugf(0, "rohc_alloc_compressor() no mem for compressor!\n");
          return NULL;
        }

        comp->enabled = 1;
        comp->feedback_pointer = 0;
        comp->max_cid = max_cid;
        comp->large_cid = 0;
        comp->mrru = 0;

        for (i = 0; i < C_NUM_PROFILES; i++) {
                comp->profiles[i] = 0;
        }

        comp->num_packets = 0;
        comp->total_compressed_size = 0;
        comp->total_uncompressed_size = 0;

        for (i=0; i<FEEDBACK_BUFFER_SIZE; i++) {
          comp->feedback_buffer[i] = (void*)0;
          comp->feedback_size[i] = 0;
        }

        if (!c_create_contexts(comp)) {
                return NULL;
        }

        return comp;
}


/* Free space used by a compressor */
void rohc_free_compressor(struct sc_rohc *comp) {

        rohc_debugf(2,"ROHC: Free contexts\n");
        // free memory used by contexts..
        c_destroy_contexts(comp);

        rohc_debugf(2,"ROHC: Free piggybacks\n");
        // destroy unsent piggybacked feedback
        c_piggyback_destroy(comp);

        // free profile array
        rohc_debugf(2,"ROHC: Free profiles\n");

        // free compressor..
        kfree(comp);
}


/* Compress a packet */
int     rohc_compress(struct sc_rohc *comp, unsigned char *ibuf, int isize,
                   unsigned char *obuf, int osize)
{
        struct iphdr *ip = (struct iphdr *)(ibuf); // + PPP_HDRLEN);
        int proto = ip->protocol;
        struct sc_profile *p;
        struct sc_context *c;
        int feedback_size, payload_size, payload_offset;
        int size, esize;

        if (comp == 0) {
                rohc_debugf(0, "c_compress(): comp=null!\n");
                return 0;
        }

        if (ip->version != 4) {
                rohc_debugf(0, "Wrong IP version (%d)\n", ip->version);
                return 0;
        }

        if (ip->ihl*4 != 20) {
                rohc_debugf(0, "Wrong IP header size (%d)\n", ip->ihl);
                return 0;
        }

        // Get profile based on ip->protocol..
        rohc_debugf(2,"c_compress(): protocoll %d \n", proto);
        p = c_get_profile_from_protocol(comp, proto);

        if (p == 0) // use IP-profile if no profile was found based on the protocol
        {
                rohc_debugf(2,"c_compress(): Using IP profile\n");
                p = c_get_profile_from_id(comp, ROHC_PROFILE_IP);

                if (p == 0) { // Use Uncompressed-profile if IP profile was not found..
                        rohc_debugf(0,"c_compress(): Using UNCOMPRESSED profile\n");
                        p = c_get_profile_from_id(comp, ROHC_PROFILE_UNCOMPRESSED);

                        if (p == 0) {
                                rohc_debugf(0,"c_compress(): No profile found, giving up\n");
                                return 0;
                        }
                }
        }


        // Get Context using help from the profiles..
        c = c_find_context(comp, p, ip);

        if (c==0) // skapa nytt context
                c = c_create_context(comp, p, ip);
        else if (c==(struct sc_context*)-1) { 
                // the profile dedected anomalities in ip-packet (such as fragments) that made 
                // it un-compressible - switch to Uncompressed profile!
                
                p = c_get_profile_from_id(comp, ROHC_PROFILE_UNCOMPRESSED);
                c = c_find_context(comp, p,  ip); // find the uncompressed
                if (c==0)
                        c = c_create_context(comp, p, ip);
        }


        c->latest_used = get_milliseconds();

        // copy PPP header
        //memcpy(obuf, rptr, PPP_HDRLEN);
        // change protocol in ppp header to rohc-over-ppp identifier???
        size = 0; //PPP_HDRLEN;

        // add feedback
        feedback_size = c_piggyback_get(comp, obuf);
        obuf += feedback_size;
        size += feedback_size;

        // use profile to compress packet
        esize = p->encode(c, ip, isize, obuf, osize - size, &payload_offset);

        if (esize < 0) { // error while compressing.. use uncompressed..
                if (c->num_send_packets <= 1) { // free context
                        c->profile->destroy(c);
                        c->used = 0;
                }

                p = c_get_profile_from_id(comp, ROHC_PROFILE_UNCOMPRESSED);
                c = c_find_context(comp, p,  ip); // find the uncompressed
                if (c==0)
                        c = c_create_context(comp, p, ip);

                if (c!=0)
                        esize = p->encode(c, ip, isize, obuf, osize - size, &payload_offset);
                else {
                        rohc_debugf(0, "c_compress(): Failed to create uncompressed context!\n");
                        return 0;
                }
        }

        size += esize;
        obuf += esize;

        payload_size = ntohs(ip->tot_len) - payload_offset;

        rohc_debugf(2,"c_compress(): ROHC size=%d, Payload size=%d (totlen=%d, ihl=%d), outbut buffer size=%d\n", size, payload_size, ntohs(ip->tot_len), ip->ihl*4, osize);

        if (size + payload_size > osize) // packet to big!!!
        {
                // do uncompressed!!
                rohc_debugf(0,"ROHC packet to large (osize=%d, isize=%d)\n", size+payload_size, isize);
                return 0;
        }

        // copy payload to rohc packet..
        memcpy(obuf, ((unsigned char*)ip) + payload_offset, payload_size);

        obuf += payload_size;
        size += payload_size;

        // Update statistic..
        comp->num_packets ++;
        comp->total_uncompressed_size += isize;
        comp->total_compressed_size += size;

        c->total_uncompressed_size += isize;
        c->total_compressed_size += size;
        c->header_uncompressed_size += payload_offset;
        c->header_compressed_size += esize;
        c->num_send_packets ++;
        c_add_wlsb(c->total_16_uncompressed, 0, 0, isize);
        c_add_wlsb(c->total_16_compressed, 0,0, size);
        c_add_wlsb(c->header_16_uncompressed, 0, 0, payload_offset);
        c_add_wlsb(c->header_16_compressed, 0,0, esize);

        return size;
}

// Used in the handshake to active profiles that are can be used
void rohc_activate_profile(struct sc_rohc * comp, int profile)
{
        int i;
        for (i = 0; i < C_NUM_PROFILES; i++) {
                if (c_profiles[i]->id == profile) {
                        comp->profiles[i] = 1;
                        return;
                }
        }
        rohc_debugf(0, "Unknown ROHC profile with id = %d\n", profile);
}

int rohc_c_using_small_cid(struct sc_rohc * comp)
{
        return !comp->large_cid;
}

void rohc_c_set_header(struct sc_rohc *compressor, int header)
{
        compressor->max_header_size = header;
}

void rohc_c_set_mrru(struct sc_rohc *compressor, int value) {
        compressor->mrru = value;
}

void rohc_c_set_max_cid(struct sc_rohc *compressor, int value) {
        if (compressor->large_cid) {
                if (value > 0 && value < 65536)
                        compressor->max_cid = value;
        } else {
                if (value > 0 && value < 16)
                        compressor->max_cid = value;
        }
}

void rohc_c_set_large_cid(struct sc_rohc *compressor, int value) {
        if (value) {
                compressor->large_cid = 1;
        } else {
                compressor->large_cid = 0;
                if (compressor->max_cid > 15)
                        compressor->max_cid = 15;
        }
}

void rohc_c_set_connection_type(struct sc_rohc *compressor, int value) {
        compressor->connection_type = value;
}

void rohc_c_set_enable(struct sc_rohc *compressor, int value) {
        compressor->enabled = value;
}

int rohc_c_is_enabled(struct sc_rohc *compressor) {
        return compressor->enabled;
}


/* Called by proc_rohc to get information about available profiles (used in usermode ppp for handshake)*/
int     rohc_c_info(char *buffer) {
        int i;

        sprintf(buffer, "%s\n", "---Information");

        //"Profiles: 1 2 3 4"
        sprintf(buffer, "%s%s", buffer, "Profiles:");
        for (i=0; i<C_NUM_PROFILES; i++) {
                sprintf(buffer, "%s%d ", buffer, c_profiles[i]->id);
        }
        sprintf(buffer, "%s\n", buffer);

        return strlen(buffer);
}

/* Called by proc_rohc to get information about the compressor  */
int    rohc_c_statistics(struct sc_rohc *comp, char *buffer)
{
        char *save;
        struct sc_profile *p;
        int i,v;

        save = buffer;

        // Instance part..
        buffer += strlen(buffer);
        sprintf(buffer, "\n---Instance\n");
        buffer += strlen(buffer);
        sprintf(buffer, "CREATOR:%s\n", "LULEA/SMD143/2003");
        buffer += strlen(buffer);
        sprintf(buffer, "VERSION NO:%s\n", "1.0");
        buffer += strlen(buffer);
        sprintf(buffer, "STATUS:%s\n", comp->enabled?"ENABLED":"DISABLED");
        buffer += strlen(buffer);
        sprintf(buffer, "NO COMPRESSED FLOWS:%d\n", comp->num_used);
        buffer += strlen(buffer);
        sprintf(buffer, "TOTAL NO PACKETS:%d\n", comp->num_packets);
        buffer += strlen(buffer);

        if (comp->total_uncompressed_size != 0)
                v = (100 * comp->total_compressed_size) / comp->total_uncompressed_size;
        else
                v = 0;
        sprintf(buffer, "TOTAL COMPRESSION RATIO:%d%%\n", v);
        buffer += strlen(buffer);
        sprintf(buffer, "MAX_CID:%d\n", comp->max_cid);
        buffer += strlen(buffer);
        sprintf(buffer, "MRRU:%d\n", 4); // comp->mrru
        buffer += strlen(buffer);
        sprintf(buffer, "LARGE_CID:%s\n", comp->large_cid?"YES" : "NO");
        buffer += strlen(buffer);
        sprintf(buffer, "CONNECTION_TYPE:%d\n", 3);
        buffer += strlen(buffer);
        sprintf(buffer, "FEEDBACK_FREQ:%d\n", 7); // comp-> ??
        buffer += strlen(buffer);

        // profiles part
        for (i=0; i<C_NUM_PROFILES; i++) {
                p = c_profiles[i];

                sprintf(buffer, "\n---Profile\n");
                buffer += strlen(buffer);
                sprintf(buffer, "PROFILE NO:%d\n", p->id);
                buffer += strlen(buffer);
                sprintf(buffer, "ACTIVE:%s\n", comp->profiles[i]?"YES":"NO");
                buffer += strlen(buffer);
                sprintf(buffer, "VERSION NO:%s\n", p->version);
                buffer += strlen(buffer);
                sprintf(buffer, "PROFILE TYPE:%s\n", p->description);
                buffer += strlen(buffer);
        }

        return strlen(save);
}

/* Called by proc_rohc to get information about a context (cid=index)
 * Returns -2 if index is larger than allocated cids
 * Returns -1 if cid is unused
 * Else returns length if buffer..
 */
int rohc_c_context(struct sc_rohc *comp, int index, char *buffer) {
        struct sc_context *c;
        char *save;
        char *modes[4]= {"error", "U-mode", "O-mode", "R-mode"};
        char *states[4] = {"error", "IR", "FO", "SO"};
        int v;

        // Compressor Contexts
        if (index >= comp->num_allocated)
                return -2;

        c = &comp->contexts[index];
        if (!c->used)
                return -1;

        save = buffer;
        buffer += strlen(buffer);
        sprintf(buffer, "\n%s\n", "---Context");
        buffer += strlen(buffer);
        sprintf(buffer, "CONTEXTTYPE:Compressor\n");
        buffer += strlen(buffer);
        sprintf(buffer, "CID:%d\n", c->cid);
        buffer += strlen(buffer);
        sprintf(buffer, "CID_STATE:%s\n", c->used?"USED":"UNUSED");
        buffer += strlen(buffer);
        sprintf(buffer, "STATE:%s\n", states[c->c_state]);
        buffer += strlen(buffer);
        sprintf(buffer, "MODE:%s\n", modes[c->c_mode]);
        buffer += strlen(buffer);
        sprintf(buffer, "PROFILE:%s\n", c->profile->description);
        buffer += strlen(buffer);

        if (c->total_uncompressed_size != 0)
                v = (100*c->total_compressed_size) / c->total_uncompressed_size;
        else
                v = 0;
        if (v < 0) {
                rohc_debugf(0, "comp: total_compressed_size=%d total_uncompressed_size=%d\n", c->total_compressed_size, c->total_uncompressed_size);
        }
        sprintf(buffer, "TOTALCOMPRATIOALLPACK:%d%%\n", v);
        buffer += strlen(buffer);

        if (c->header_uncompressed_size != 0)
                v = (100*c->header_compressed_size) / c->header_uncompressed_size;
        else
                v = 0;
        sprintf(buffer, "TOTALCOMPRATIOALLPACKHEAD:%d%%\n", v);
        buffer += strlen(buffer);

        if (c->num_send_packets != 0)
                v = c->total_compressed_size / c->num_send_packets;
        else
                v = 0;
        sprintf(buffer, "MEANCOMPPACKSIZEALLPACK:%d\n", v);
        buffer += strlen(buffer);

        if (c->num_send_packets != 0)
                v = c->header_compressed_size / c->num_send_packets;
        else
                v = 0;
        sprintf(buffer, "MEANHEADSIZEALLCOMPHEAD:%d\n", v);
        buffer += strlen(buffer);

        v = c_sum_wlsb(c->total_16_uncompressed);
        if (v != 0)
                v = (100*c_sum_wlsb(c->total_16_compressed)) / v;
        sprintf(buffer, "COMPRATIOLAST16PACK:%d%%\n", v);
        buffer += strlen(buffer);

        v = c_sum_wlsb(c->header_16_uncompressed);
        if (v != 0)
                v = (100*c_sum_wlsb(c->header_16_compressed)) / v;
        sprintf(buffer, "COMPRATIOLAST16PACKHEAD:%d%%\n", v);
        buffer += strlen(buffer);

        v = c_mean_wlsb(c->total_16_compressed);
        sprintf(buffer, "MEANCOMPPACKSIZELAST16PACK:%d\n", v);
        buffer += strlen(buffer);

        v = c_mean_wlsb(c->header_16_compressed);
        sprintf(buffer, "MEANHEADSIZELAST16COMPHEAD:%d\n", v);
        buffer += strlen(buffer);
        sprintf(buffer, "CONTEXTACTIVATIONTIME:%d\n", (get_milliseconds() - c->first_used)/1000);
        buffer += strlen(buffer);
        sprintf(buffer, "CONTEXTIDLETIME:%d\n", (get_milliseconds() - c->latest_used)/1000);
        buffer += strlen(buffer);
        sprintf(buffer, "NOSENTPACKETS:%d\n", c->num_send_packets);
        buffer += strlen(buffer);
        sprintf(buffer, "NOSENTIRPACKETS:%d\n", c->num_send_ir);
        buffer += strlen(buffer);
        sprintf(buffer, "NOSENTIRDYNPACKETS:%d\n", c->num_send_ir_dyn);
        buffer += strlen(buffer);
        sprintf(buffer, "NORECVFEEDBACKS:%d\n", c->num_recv_feedbacks);

        return strlen(save);
}


////////////////////////////////////////////////////////////////////////
// Generic profile functions

// Retrieve a profile given a profile_id
struct sc_profile *c_get_profile_from_id(struct sc_rohc *comp, int profile_id)
{
        int i;
        for (i=0; i<C_NUM_PROFILES; i++)
        {
                if (c_profiles[i]->id == profile_id && comp->profiles[i]==1)
                        return c_profiles[i];
        }

        // log this failure maybe..
        return NULL;
}

// Retrieve a profile given a (ip) protocol id
struct sc_profile *c_get_profile_from_protocol(struct sc_rohc *comp, int protocol)
{
        int i;
        for (i=0; i<C_NUM_PROFILES; i++)
        {
                if (c_profiles[i]->protocol == protocol && comp->profiles[i]==1)
                        return c_profiles[i];
        }

        return NULL;
}

////////////////////////////////////////////////////////////////////////
// Generic context functions


// Allocate the context array
static int c_alloc_contexts(struct sc_rohc *comp, int num) {
        if (num > comp->max_cid+1)
                num = comp->max_cid+1;

        if (comp->num_allocated < num) {
                struct sc_context *tmp;
                int i;

                tmp = kmalloc(sizeof(struct sc_context) * num, GFP_ATOMIC);
                if (tmp == 0) {
                      rohc_debugf(0,"rohc_alloc_compressor() no mem for contexts!\n");
                      return 0;
                }

                for (i=0; i<num; i++) {
                        tmp[i].used = 0;
                }

                if (comp->num_allocated > 0 && comp->contexts) {
                        memcpy(tmp,comp->contexts, comp->num_allocated * sizeof(struct sc_context));
                        kfree(comp->contexts);
                }

                for (i=comp->num_allocated; i<num; i++) {
                        tmp[i].total_16_uncompressed = c_create_wlsb(32, 16, 0); // create a window with 16 entries..
                        tmp[i].total_16_compressed = c_create_wlsb(32, 16, 0);
                        tmp[i].header_16_uncompressed = c_create_wlsb(32, 16, 0);
                        tmp[i].header_16_compressed = c_create_wlsb(32, 16, 0);
                }

                comp->contexts = tmp;
                comp->num_allocated = num;
        }

        return 1;
}

// Skapa en ny context
struct sc_context *c_create_context(struct sc_rohc *comp, struct sc_profile *profile, struct iphdr *ip) {
        struct sc_context *c;
        int index, i;

        index = 0;

        if (comp->num_used >= comp->max_cid+1) {
                // find oldest or one not in use:
                int minimum;

find_oldest:

                index = 0;
                minimum = 0x7fffffff;
                for (i=0; i<comp->num_allocated; i++) {
                        if (comp->contexts[i].used == 0) {
                                index = i;
                                break;
                        } else if (comp->contexts[i].latest_used < minimum) {
                                minimum = comp->contexts[i].latest_used;
                                index = i;
                        }
                }

                if (comp->contexts[index].used) {
                        // free memory..
                        rohc_debugf(2,"Freeing memory for recycled context (cid=%d)\n", index);
                        comp->contexts[index].profile->destroy(&comp->contexts[index]);
                }

        } else if (comp->num_used >= comp->num_allocated) {
                if (!c_alloc_contexts(comp, comp->num_used * 2))
                        goto find_oldest;

                index = comp->num_used;
                comp->num_used ++;

        } else{
                index = -1;
                for (i=0; i<comp->num_used; i++) {
                        if (comp->contexts[i].used==0) {
                                index = i;
                                break;
                        }
                }

                if (index==-1) {
                        index = comp->num_used;
                        comp->num_used++;
                }
        }


        c = &comp->contexts[index];

        c->used = 1;
        c->first_used = get_milliseconds();
        c->latest_used = get_milliseconds();

        c->total_uncompressed_size = 0;
        c->total_compressed_size = 0;
        c->header_uncompressed_size = 0;
        c->header_compressed_size = 0;
        c->num_send_packets = 0;
        c->num_send_ir = 0;
        c->num_send_ir_dyn = 0;
        c->num_recv_feedbacks = 0;

        c->cid = index;

        c->profile = profile;
        c->profile_id = profile->id;

        c->c_mode = U;
        c->c_state = IR;

        c->nbo = 1;
        c->rnd = 0;

        c->nbo2 = 1;
        c->rnd2 = 0;

        c->compressor = comp;
        c->latest_used = get_milliseconds();

        rohc_debugf(1, "Creating context CID=%d (numUsed=%d)\n", c->cid, comp->num_used);

        // Create profile specific context and initialize..
        if (profile->create(c, ip) == 0) {
                c->used = 0;
                return NULL;
        }

        return c;
}


// Find context given a profile and a ip packet..
struct sc_context *c_find_context(struct sc_rohc *comp, struct sc_profile *profile, struct iphdr *ip) {
        int i;
        int ret;
        struct sc_context *c;

        rohc_debugf(2,"c_find_context(): %d\n", comp->num_used);

        for (i=0; i<comp->num_used; i++) {
                c = &comp->contexts[i];

                if (c && !c->used) {
                        rohc_debugf(1,"Using unused context CID=%d\n", c->cid);
                        return c;
                }
                if (c && c->used && c->profile_id==profile->id) {
                        ret = c->profile->check_context(c, ip);

                        if (ret==-1)
                                return (struct sc_context*)-1;
                        if (ret) {
                                rohc_debugf(1,"Using context CID=%d\n", c->cid);
                                return c;
                        }
                }
        }

        rohc_debugf(2,"c_find_context(): No context was found\n");
        return NULL; // no matching context was found..
}


// Get context, given the CID
struct sc_context *c_get_context(struct sc_rohc *comp, int cid) {
        if (cid > comp->num_allocated)
                return NULL;
        if (cid > comp->num_used)
                return NULL;
        if (comp->contexts[cid].used == 0)
                return NULL;

        return &comp->contexts[cid];
}


// Allocate context memory..
static int c_create_contexts(struct sc_rohc *comp) {
        comp->num_used = 0;
        comp->num_allocated = 0;
        comp->contexts = 0;

        return c_alloc_contexts(comp, 4); // start with 4 contexts from the beginning..
}


// Deallocate all contexts including their profile specific context
static void c_destroy_contexts(struct sc_rohc *comp) {
        if (comp->num_allocated > 0) {
                int i;
                for (i=0; i<comp->num_allocated; i++) {

                        if (comp->contexts[i].used && comp->contexts[i].profile != 0)
                                comp->contexts[i].profile->destroy(&comp->contexts[i]);

                        c_destroy_wlsb(comp->contexts[i].total_16_uncompressed);
                        c_destroy_wlsb(comp->contexts[i].total_16_compressed);
                        c_destroy_wlsb(comp->contexts[i].header_16_uncompressed);
                        c_destroy_wlsb(comp->contexts[i].header_16_compressed);

                        comp->contexts[i].used = 0;

                }

                kfree(comp->contexts);
        }
}


////////////////////////////////////////////////////////////////////////
// Feedback functions for piggybacking

// Add this feedback to the next outgoing ROHC packet:
void c_piggyback_feedback(struct sc_rohc *comp, unsigned char *feedback, int size) {
        if (comp->feedback_pointer >= FEEDBACK_BUFFER_SIZE) // log this failure maybe?
                return;

        comp->feedback_buffer[comp->feedback_pointer] = kmalloc(size, GFP_ATOMIC);
        if (comp->feedback_buffer[comp->feedback_pointer] == 0) {
          rohc_debugf(0,"c_piggyback_feedback() no mem for feedback!\n");
          return;
        }
        memcpy(comp->feedback_buffer[comp->feedback_pointer], feedback, size);
        comp->feedback_size[comp->feedback_pointer] = size;

        comp->feedback_pointer++;
}

// Retrieve one feedback and store in buf. Return length of feedback
static int c_piggyback_get(struct sc_rohc *comp, unsigned char *buf) {
        if (comp->feedback_pointer > 0) {
                int size;
                int index=0;

                comp->feedback_pointer--;
                size = comp->feedback_size[comp->feedback_pointer];
                if (size < 8) {
                        buf[index] = 0xf0 | size;
                        index++;
                } else {
                        buf[index] = 0xf0;
                        index++;
                        buf[index] = size;
                        index++;
                }

                memcpy(buf+index, comp->feedback_buffer[comp->feedback_pointer], size);

                kfree(comp->feedback_buffer[comp->feedback_pointer]);
                comp->feedback_size[comp->feedback_pointer] = 0;

                return index + size;
        }

        // No feedback exists..
        return 0;
}

// Destory memory allocated by the feedback buffer
static void c_piggyback_destroy(struct sc_rohc *comp) {
        int i;

        for (i=0; i<FEEDBACK_BUFFER_SIZE; i++) {
                if (comp->feedback_size[i] > 0 && comp->feedback_buffer[i] != 0)
                        kfree(comp->feedback_buffer[i]);
        }
}

////////////////////////////////////////////////////////////////////////
// Feedback functions delivery to right profile/context..


// When feedback is received by the decompressor, this function is called
// and delivers that to the right profile/context..
void c_deliver_feedback(struct sc_rohc *comp, unsigned char *packet, int size) {
        struct sc_context *c;
        struct sc_feedback feedback;
        unsigned char *p = packet;

        feedback.size = size;

        if (comp->large_cid) { // decode large cid.at p[0..3]
                feedback.cid =  d_sdvalue_decode(p);
                p += d_sdvalue_size(p);
        } else {
                if (d_is_add_cid(p)) {
                        feedback.cid = d_decode_add_cid(p);
                        p++;
                } else
                        feedback.cid = 0;
        }

        feedback.specific_size = size - (p - packet);
        rohc_debugf(2,"feedback size = %d\n",feedback.specific_size);
        if (feedback.specific_size == 1)
                feedback.type = 1;  // FEEDBACK-1
        else {
                feedback.type = 2;  // FEEDBACK-2
                feedback.acktype = p[0]>>6;
        }

        feedback.specific_offset = (p - packet);
        feedback.data = kmalloc(feedback.size, GFP_ATOMIC);

        if (feedback.data == 0) {
          rohc_debugf(0, "c_deliver_feedback(): no mem for feedback data\n");
          return;
        }

        rohc_debugf(2, "spec size    %d\n",feedback.specific_size);

        memcpy(feedback.data,packet,feedback.size );

        // find cid.. get context
        c = c_get_context(comp,feedback.cid);
        if (c==0){
                // Error: Context was not found..
                rohc_debugf(0, "c_deliver_feedback(): Context not found (cid=%d)\n", feedback.cid);
                kfree(feedback.data);
                return;
        }

        c->num_recv_feedbacks++;

        // deliver feedback to profile with the context..
        c->profile->feedback(c, &feedback);

        kfree(feedback.data);

}


Revision:	1.3
Committed:	Tue Apr 26 00:55:56 2005 UTC (19 years, 1 month ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_01, rel-3_0, rel-2_2, rel-2_0, rel-2_21, rel-2_22, rel-2_25, HEAD
Changes since 1.2:	+1 -1 lines
Log Message:	* empty log message *