Fix: MLPPP complete lost frame.

[l2tpns.git] / ppp.c

diff --git a/ppp.c b/ppp.c
index 7942e6e..e805e22 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,7 +1,5 @@
 // L2TPNS PPP Stuff
 
 // L2TPNS PPP Stuff
 

-char const *cvs_id_ppp = "$Id: ppp.c,v 1.104 2009/12/08 14:49:28 bodea Exp $";
-

 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>


@@ -821,6 +819,10 @@ void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                        break;
 
 
                        break;
 

+               case Closing:
+                       sessionshutdown(s, "LCP: ConfigReq in state Closing. This should not happen. Killing session.", CDN_ADMIN_DISC, TERM_LOST_SERVICE);
+                       break;
+

                default:
                        LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
                        return;
                default:
                        LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
                        return;


@@ -1536,7 +1538,7 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                uint8_t *o = p + 4;
                int length = l - 4;
                int gotip = 0;
                uint8_t *o = p + 4;
                int length = l - 4;
                int gotip = 0;

-               uint8_t ident[8];
+               uint32_t ident[2];

 
                while (length > 2)
                {
 
                while (length > 2)
                {


@@ -1548,12 +1550,12 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                gotip++; // seen address
                                if (o[1] != 10) return;
 
                                gotip++; // seen address
                                if (o[1] != 10) return;
 

-                               *(uint32_t *) ident = htonl(session[s].ip);
-                               *(uint32_t *) (ident + 4) = 0;
+                               ident[0] = htonl(session[s].ip);
+                               ident[1] = 0;

 
                                if (memcmp(o + 2, ident, sizeof(ident)))
                                {
 
                                if (memcmp(o + 2, ident, sizeof(ident)))
                                {

-                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
+                                       q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, (uint8_t *)ident, sizeof(ident));

                                        if (!q) return;
                                }
 
                                        if (!q) return;
                                }
 


@@ -1807,130 +1809,303 @@ void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 // process Multilink PPP packet received
 void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {
 // process Multilink PPP packet received
 void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 {

-        bundleidt b = session[s].bundle;
+       bundleidt b = session[s].bundle;

        bundlet * this_bundle = &bundle[b];
        bundlet * this_bundle = &bundle[b];

-       uint32_t frag_offset, M_offset;
-       uint16_t frag_index, M_index;
+       uint32_t maskSeq, max_seq;
+       int frag_offset;
+       uint16_t frag_index, frag_index_next, frag_index_prev;

        fragmentationt *this_fragmentation = &frag[b];
        uint8_t begin_frame = (*p & MP_BEGIN);
        fragmentationt *this_fragmentation = &frag[b];
        uint8_t begin_frame = (*p & MP_BEGIN);

-        uint8_t end_frame = (*p & MP_END);
-        uint32_t seq_num;
+       uint8_t end_frame = (*p & MP_END);
+       uint32_t seq_num, seq_num_next, seq_num_prev;
+       uint32_t i;

        uint8_t flags = *p;
        uint8_t flags = *p;

-       uint16_t begin_index, end_index;
+       uint16_t begin_index, end_index, start_index;

 
        // Perform length checking
 
        // Perform length checking

-        if(l > MAXFRAGLEN)
-        {
-               LOG(2, s, t, "MPPP: discarding fragment larger than MAXFRAGLEN\n");
-               return;
-        }
+       if(l > MAXFRAGLEN)
+       {
+               LOG(2, s, t, "MPPP: discarding fragment larger than MAXFRAGLEN\n");
+               return;
+       }

 
 

-        if(!b)
-        {
-                LOG(2, s, t, "MPPP: Invalid bundle id: 0\n");
-                return;
-        }
+       if(!b)
+       {
+               LOG(2, s, t, "MPPP: Invalid bundle id: 0\n");
+               return;
+       }

        // FIXME !! session[s].mssf means that the receiver wants to receive frames in mssf not means the receiver will send frames in mssf
        // FIXME !! session[s].mssf means that the receiver wants to receive frames in mssf not means the receiver will send frames in mssf

-        /* if(session[s].mssf)
-        {
-                // Get 12 bit for seq number
-                seq_num = ntohs((*(uint16_t *) p) & 0xFF0F);
-                p += 2;
-                l -= 2;
-                // After this point the pointer should be advanced 2 bytes
-                LOG(3, s, t, "MPPP: 12 bits, sequence number: %d\n",seq_num);
-        }
-        else */
-        {
-                // Get 24 bit for seq number
-                seq_num = ntohl((*(uint32_t *) p) & 0xFFFFFF00);
-                p += 4;
-                l -= 4;
-                // After this point the pointer should be advanced 4 bytes
-                LOG(4, s, t, "MPPP: 24 bits sequence number:%d\n",seq_num);
-        }
+       /* if(session[s].mssf)
+       {
+               // Get 12 bit for seq number
+               seq_num = ntohs((*(uint16_t *) p) & 0xFF0F);
+               p += 2;
+               l -= 2;
+               // After this point the pointer should be advanced 2 bytes
+               LOG(3, s, t, "MPPP: 12 bits, sequence number: %d\n",seq_num);
+       }
+       else */
+       {
+               // Get 24 bit for seq number
+               seq_num = ntohl((*(uint32_t *) p) & 0xFFFFFF00);
+               p += 4;
+               l -= 4;
+               // After this point the pointer should be advanced 4 bytes
+               LOG(4, s, t, "MPPP: 24 bits sequence number:%d\n",seq_num);
+       }

 
 

-       // calculate this fragment's offset from the begin seq in the bundle
-       frag_offset = (seq_num + this_bundle->max_seq - this_fragmentation->start_seq) & (this_bundle->max_seq-1);
+       max_seq = this_bundle->max_seq;
+       maskSeq = max_seq - 1;

 
 

-       // discard this fragment if frag_offset is bigger that the fragmentation buffer size
-       if (frag_offset >= MAXFRAGNUM)
-        {
-               LOG(3, s, t, "MPPP: Index out of range, received more than MAXFRAGNUM fragment (lost frag) seq:%d, begin_seq:%d, bundle:%d, max:%d\n",seq_num, this_fragmentation->start_seq, b, this_bundle->max_seq);
-                return;
-        }
+       /*
+        * Expand sequence number to 32 bits, making it as close
+        * as possible to this_fragmentation->M.
+        */
+       seq_num |= this_fragmentation->M & ~maskSeq;
+       if ((int)(this_fragmentation->M - seq_num) > (int)(maskSeq >> 1))
+       {
+               seq_num += maskSeq + 1;
+       }
+       else if ((int)(seq_num - this_fragmentation->M) > (int)(maskSeq >> 1))
+       {
+               seq_num -= maskSeq + 1; /* should never happen */
+       }
+
+       // calculate this fragment's offset from the begin seq in the bundle
+       frag_offset = (int) (seq_num - this_fragmentation->start_seq);
+       start_index = this_fragmentation->start_index;

        
        

-       // update M

        sess_local[s].last_seq = seq_num;
        sess_local[s].last_seq = seq_num;

+
+       uint32_t min;
+

        if (seq_num < this_fragmentation->M)
        if (seq_num < this_fragmentation->M)

+       {
+               min = seq_num;

                this_fragmentation->M = seq_num;
                this_fragmentation->M = seq_num;

+       }

        else
        {
        else
        {

-               uint32_t i, min = sess_local[(this_bundle->members[0])].last_seq;;
+               min = sess_local[(this_bundle->members[0])].last_seq;

                for (i = 1; i < this_bundle->num_of_links; i++)
                {
                for (i = 1; i < this_bundle->num_of_links; i++)
                {

-                       uint32_t s_seq = sess_local[(this_bundle->members[i])].last_seq; 
+                       uint32_t s_seq = sess_local[(this_bundle->members[i])].last_seq;

                        if (s_seq < min)
                                min = s_seq;
                }
                this_fragmentation->M = min;
        }
 
                        if (s_seq < min)
                                min = s_seq;
                }
                this_fragmentation->M = min;
        }
 

-       LOG(4, s, t, "MPPP: Setting M to %d\n", this_fragmentation->M); 
-       //calculate M's offset from the begin seq in the bundle
-       M_offset = (this_fragmentation->M + this_bundle->max_seq - this_fragmentation->start_seq) & (this_bundle->max_seq-1);
+       if (min >= (this_fragmentation->start_seq + this_bundle->num_of_links))
+       {
+               // Find the new start sequence, the previous frag are lost
+               // calculate M offset of the M seq in the bundle
+               int M_offset = (int) (min - this_fragmentation->start_seq);
+               begin_index = (M_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
+
+               if (M_offset >= MAXFRAGNUM)
+               {
+                       // There have a long break of the link !!!!!!!!
+                       // M_offset is bigger that the fragmentation buffer size
+                       LOG(3, s, t, "MPPP: M_offset out of range, min:%d, begin_seq:%d, size frag:%d\n", min, this_fragmentation->start_seq, l);
+
+                       // Set new Start sequence
+                       this_fragmentation->start_index = begin_index;
+                       this_fragmentation->start_seq = min;
+                       M_offset = 0;
+                       // recalculate the fragment offset from the new begin seq in the bundle
+                       frag_offset = (int) (seq_num - min);
+               }
+               else if (M_offset > 0)
+               {
+                       uint32_t b_seq = min;
+                       if ((min == seq_num) && begin_frame)
+                       {
+                               // Set new Start sequence
+                               this_fragmentation->start_index = begin_index;
+                               this_fragmentation->start_seq = min;
+                               frag_offset = 0;
+                       }
+                       else
+                       {
+                               if (min == seq_num)
+                               {
+                                       M_offset--;
+                                       begin_index = (begin_index ? (begin_index -1) : (MAXFRAGNUM -1));
+                                       b_seq--;
+                               }
+
+                               // Find the Begin sequence
+                               while (this_fragmentation->fragment[begin_index].length)
+                               {
+                                       if (b_seq == this_fragmentation->fragment[begin_index].seq)
+                                       {
+                                               if (this_fragmentation->fragment[begin_index].flags & MP_BEGIN)
+                                                       break;
+                                       }
+                                       else
+                                       {
+                                               // This fragment is lost, it was never completed the packet.
+                                               LOG(3, this_fragmentation->fragment[begin_index].sid, this_fragmentation->fragment[begin_index].tid,
+                                                       "MPPP: (FIND) seq_num:%d frag_index:%d flags:%d is LOST\n",
+                                                       this_fragmentation->fragment[begin_index].seq, begin_index, this_fragmentation->fragment[begin_index].flags);
+                                               // this frag is lost
+                                               this_fragmentation->fragment[begin_index].length = 0;
+                                               this_fragmentation->fragment[begin_index].flags = 0;
+                                               break;
+                                       }
+                                       begin_index = (begin_index ? (begin_index -1) : (MAXFRAGNUM -1));
+                                       b_seq--;
+                               }

 
 

-       //caculate M's index in the fragment array
-       M_index = (M_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
+                               // begin sequence found ?
+                               if (this_fragmentation->fragment[begin_index].length)
+                               {
+                                       // Set new Start sequence
+                                       this_fragmentation->start_index = begin_index;
+                                       this_fragmentation->start_seq = b_seq;
+                                       // recalculate the fragment offset from the new begin seq in the bundle
+                                       frag_offset = (int) (seq_num - b_seq);
+                               }
+                       }
+               }
+       }
+       else if ((this_fragmentation->fragment[start_index].length) &&
+                        (!(this_fragmentation->fragment[start_index].flags & MP_BEGIN)))
+       {
+               uint32_t f_seq = this_fragmentation->start_seq;
+               end_index = start_index;
+               // Find the Begin sequence
+               while (this_fragmentation->fragment[end_index].length)
+               {
+                       if (f_seq == this_fragmentation->fragment[end_index].seq)
+                       {
+                               if (this_fragmentation->fragment[end_index].flags & MP_BEGIN)
+                                       break;
+                       }
+                       else
+                       {
+                               // This fragment is lost, it was never completed the packet.
+                               LOG(3, this_fragmentation->fragment[end_index].sid, this_fragmentation->fragment[end_index].tid,
+                                       "MPPP: (FIND2) seq_num:%d frag_index:%d flags:%d is LOST\n",
+                                       this_fragmentation->fragment[end_index].seq, end_index, this_fragmentation->fragment[end_index].flags);
+                               // this frag is lost
+                               this_fragmentation->fragment[end_index].length = 0;
+                               this_fragmentation->fragment[end_index].flags = 0;
+                               break;
+                       }
+                       end_index = (end_index +1) & MAXFRAGNUM_MASK;
+                       f_seq++;
+               }
+
+               // Set new Start sequence
+               this_fragmentation->start_index = end_index;
+               this_fragmentation->start_seq = f_seq;
+               // recalculate the fragment offset from the new begin seq in the bundle
+               frag_offset = (int) (seq_num - f_seq);
+       }
+
+       // discard this fragment if the packet comes before the start sequence
+       if (frag_offset < 0)
+       {
+               // this packet comes before the next
+               LOG(3, s, t, "MPPP: packet comes before the next, seq:%d, begin_seq:%d, size frag:%d\n", seq_num, this_fragmentation->start_seq, l);
+               return;
+       }

        
        

+       // discard if frag_offset is bigger that the fragmentation buffer size
+       if (frag_offset >= MAXFRAGNUM)
+       {
+               // frag_offset is bigger that the fragmentation buffer size
+               LOG(3, s, t, "MPPP: Index out of range, seq:%d, begin_seq:%d, size frag:%d\n", seq_num, this_fragmentation->start_seq, l);
+               return;
+       }
+

        //caculate received fragment's index in the fragment array
        frag_index = (frag_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
 
        //caculate received fragment's index in the fragment array
        frag_index = (frag_offset + this_fragmentation->start_index) & MAXFRAGNUM_MASK;
 

-       //frame with a single fragment
-       if (begin_frame && end_frame)
-       {
-               // process and reset fragmentation
-                LOG(4, s, t, "MPPP: Both bits are set (Begin and End).\n");
-               this_fragmentation->fragment[frag_index].length = l;
-               this_fragmentation->fragment[frag_index].sid = s;
-               this_fragmentation->fragment[frag_index].flags = flags;
-               this_fragmentation->fragment[frag_index].seq = seq_num;
-               this_fragmentation->re_frame_begin_index = frag_index;
-               this_fragmentation->re_frame_end_index = frag_index;
-               processmpframe(s, t, p, l, 0);
-               this_fragmentation->fragment[frag_index].length = 0;
-               this_fragmentation->fragment[frag_index].flags = 0;
-               end_index = frag_index;
-       }
-       else

        {
                // insert the frame in it's place
                fragmentt *this_frag = &this_fragmentation->fragment[frag_index];
        {
                // insert the frame in it's place
                fragmentt *this_frag = &this_fragmentation->fragment[frag_index];

+
+               if (this_frag->length > 0)
+                       // This fragment is lost, It was around the buffer and it was never completed the packet.
+                       LOG(3, this_frag->sid, this_frag->tid, "MPPP: (INSERT) seq_num:%d frag_index:%d flags:%d is LOST\n",
+                               this_frag->seq, frag_index, this_frag->flags);
+

                this_frag->length = l;
                this_frag->sid = s;
                this_frag->flags = flags;
                this_frag->seq = seq_num;
                this_frag->length = l;
                this_frag->sid = s;
                this_frag->flags = flags;
                this_frag->seq = seq_num;

-                memcpy(this_frag->data, p, l);
+               memcpy(this_frag->data, p, l);
+
+               LOG(4, s, t, "MPPP: seq_num:%d frag_index:%d INSERTED flags: %02X\n",  seq_num, frag_index, flags);
+
+               //next frag index
+               frag_index_next = (frag_index + 1) & MAXFRAGNUM_MASK;
+               //previous frag index
+               frag_index_prev = (frag_index - 1) & MAXFRAGNUM_MASK;
+               // next seq
+               seq_num_next = seq_num + 1;
+               // previous seq
+               seq_num_prev = seq_num - 1;
+
+               if ((frag_index_next != this_fragmentation->start_index) && this_fragmentation->fragment[frag_index_next].length)
+               {
+                       // check if the next frag is a lost fragment
+                       if (this_fragmentation->fragment[frag_index_next].seq != seq_num_next)
+                       {
+                               // This fragment is lost, It was around the buffer and it was never completed the packet.
+                               LOG(3, this_fragmentation->fragment[frag_index_next].sid, this_fragmentation->fragment[frag_index_next].tid,
+                                       "MPPP: (NEXT) seq_num:%d frag_index:%d flags:%d is LOST\n",
+                                       this_fragmentation->fragment[frag_index_next].seq, frag_index_next, this_fragmentation->fragment[frag_index_next].flags);
+                               // this frag is lost
+                               this_fragmentation->fragment[frag_index_next].length = 0;
+                               this_fragmentation->fragment[frag_index_next].flags = 0;
+
+                               if (begin_frame && (!end_frame)) return; // assembling frame failed
+                       }
+               }
+
+               if ((frag_index != this_fragmentation->start_index) && this_fragmentation->fragment[frag_index_prev].length)
+               {
+                       // check if the next frag is a lost fragment
+                       if (this_fragmentation->fragment[frag_index_prev].seq != seq_num_prev)
+                       {
+                               // This fragment is lost, It was around the buffer and it was never completed the packet.
+                               LOG(3, this_fragmentation->fragment[frag_index_prev].sid, this_fragmentation->fragment[frag_index_prev].tid,
+                                       "MPPP: (PREV) seq_num:%d frag_index:%d flags:%d is LOST\n",
+                                       this_fragmentation->fragment[frag_index_prev].seq, frag_index_prev, this_fragmentation->fragment[frag_index_prev].flags);
+
+                               this_fragmentation->fragment[frag_index_prev].length = 0;
+                               this_fragmentation->fragment[frag_index_prev].flags = 0;

 
 

+                               if (end_frame && (!begin_frame)) return; // assembling frame failed
+                       }
+               }
+
+assembling_frame:

                // try to assemble the frame that has the received fragment as a member         
                // get the beginning of this frame
                // try to assemble the frame that has the received fragment as a member         
                // get the beginning of this frame

-               begin_index = end_index = frag_index;
-               while (this_fragmentation->fragment[begin_index].length)
+               begin_index = end_index = this_fragmentation->start_index;
+               if (this_fragmentation->fragment[begin_index].length)

                {
                {

-                       if (this_fragmentation->fragment[begin_index].flags & MP_BEGIN)
-                               break;
-                       begin_index = (begin_index ? (begin_index -1) : (MAXFRAGNUM -1)); 
+                       if (!(this_fragmentation->fragment[begin_index].flags & MP_BEGIN))
+                               return; // assembling frame failed

                }
                }

-
-               // return if a lost fragment is found
-               if (!(this_fragmentation->fragment[begin_index].length))
+               else

                        return; // assembling frame failed
                        return; // assembling frame failed

+

                // get the end of his frame
                while (this_fragmentation->fragment[end_index].length)
                {
                        if (this_fragmentation->fragment[end_index].flags & MP_END)
                                break;
                // get the end of his frame
                while (this_fragmentation->fragment[end_index].length)
                {
                        if (this_fragmentation->fragment[end_index].flags & MP_END)
                                break;

-                       end_index = (end_index +1) & MAXFRAGNUM_MASK; 
+
+                       end_index = (end_index +1) & MAXFRAGNUM_MASK;
+
+                       if (end_index == this_fragmentation->start_index)
+                               return; // assembling frame failed

                }
 
                // return if a lost fragment is found
                }
 
                // return if a lost fragment is found


@@ -1940,35 +2115,37 @@ void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                // assemble the packet
                //assemble frame, process it, reset fragmentation
                uint16_t cur_len = 4;   // This is set to 4 to leave 4 bytes for function processipin
                // assemble the packet
                //assemble frame, process it, reset fragmentation
                uint16_t cur_len = 4;   // This is set to 4 to leave 4 bytes for function processipin

-               uint32_t i;

 
 

-                       LOG(4, s, t, "MPPP: processing fragments from %d to %d\n", begin_index, end_index);
-                       // Push to the receive buffer
-                                       
+               LOG(4, s, t, "MPPP: processing fragments from %d to %d\n", begin_index, end_index);
+               // Push to the receive buffer
+

                for (i = begin_index;; i = (i + 1) & MAXFRAGNUM_MASK)
                for (i = begin_index;; i = (i + 1) & MAXFRAGNUM_MASK)

-                {
+               {

                        this_frag = &this_fragmentation->fragment[i];
                        this_frag = &this_fragmentation->fragment[i];

-                        if(cur_len + this_frag->length > MAXETHER)
-                        {
-                                LOG(2, s, t, "MPPP: discarding reassembled frames larger than MAXETHER\n");                            
-                                break;
-                        }
-                        memcpy(this_fragmentation->reassembled_frame+cur_len, this_frag->data, this_frag->length);
+                       if(cur_len + this_frag->length > MAXETHER)
+                       {
+                               LOG(2, s, t, "MPPP: discarding reassembled frames larger than MAXETHER\n");
+                               break;
+                       }
+
+                       memcpy(this_fragmentation->reassembled_frame+cur_len, this_frag->data, this_frag->length);

                        LOG(5, s, t, "MPPP: processing frame at %d, with len %d\n", i, this_frag->length);
                        LOG(5, s, t, "MPPP: processing frame at %d, with len %d\n", i, this_frag->length);

-                        cur_len += this_frag->length;
+
+                       cur_len += this_frag->length;

                        if (i == end_index)
                        {
                                this_fragmentation->re_frame_len = cur_len;
                                this_fragmentation->re_frame_begin_index = begin_index;
                        if (i == end_index)
                        {
                                this_fragmentation->re_frame_len = cur_len;
                                this_fragmentation->re_frame_begin_index = begin_index;

-                               this_fragmentation->re_frame_end_index = end_index;
-                               // Process the resassembled frame
-                               LOG(5, s, t, "MPPP: Process the reassembled frame, len=%d\n",cur_len);
-                               processmpframe(s, t, this_fragmentation->reassembled_frame, this_fragmentation->re_frame_len, 1);
+                               this_fragmentation->re_frame_end_index = end_index;
+                               // Process the resassembled frame
+                               LOG(5, s, t, "MPPP: Process the reassembled frame, len=%d\n",cur_len);
+                               processmpframe(s, t, this_fragmentation->reassembled_frame, this_fragmentation->re_frame_len, 1);

                                break;
                        }
                                break;
                        }

-                }
-                // Set reassembled frame length to zero after processing it
-                this_fragmentation->re_frame_len = 0;
+               }
+
+               // Set reassembled frame length to zero after processing it
+               this_fragmentation->re_frame_len = 0;

                for (i = begin_index;; i = (i + 1) & MAXFRAGNUM_MASK)
                {
                        this_fragmentation->fragment[i].length = 0;      // Indicates that this fragment has been consumed
                for (i = begin_index;; i = (i + 1) & MAXFRAGNUM_MASK)
                {
                        this_fragmentation->fragment[i].length = 0;      // Indicates that this fragment has been consumed


@@ -1976,20 +2153,32 @@ void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                        if (i == end_index)
                                break;
                }
                        if (i == end_index)
                                break;
                }

+
+               // Set the new start_index and start_seq
+               this_fragmentation->start_index = (end_index + 1) & MAXFRAGNUM_MASK;
+               this_fragmentation->start_seq = this_fragmentation->fragment[end_index].seq + 1;
+
+               LOG(4, s, t, "MPPP after assembling: start index is = %d, start seq=%d\n", this_fragmentation->start_index, this_fragmentation->start_seq);
+
+               begin_index = this_fragmentation->start_index;
+               if (this_fragmentation->fragment[begin_index].length)
+               {
+                       if (this_fragmentation->fragment[begin_index].seq == this_fragmentation->start_seq)
+                       {
+                               if (this_fragmentation->fragment[begin_index].flags & MP_BEGIN)
+                                       goto assembling_frame;
+                       }
+                       else
+                       {
+                               LOG(3, this_fragmentation->fragment[begin_index].sid, this_fragmentation->fragment[begin_index].tid,
+                                       "MPPP: START seq_num:%d frag_index:%d flags:%d is LOST\n",
+                                       this_fragmentation->fragment[begin_index].seq, begin_index, this_fragmentation->fragment[begin_index].flags);
+                               this_fragmentation->fragment[begin_index].length = 0;
+                               this_fragmentation->fragment[begin_index].flags = 0;
+                       }
+               }

        }
        }

-       //discard fragments received before the recently assembled frame
-       begin_index = this_fragmentation->start_index;
-       this_fragmentation->start_index = (end_index + 1) & MAXFRAGNUM_MASK;
-        this_fragmentation->start_seq = (this_fragmentation->fragment[end_index].seq + 1) & (this_bundle->max_seq-1);
-       //clear length and flags of the discarded fragments
-       while (begin_index != this_fragmentation->start_index)
-        {
-                this_fragmentation->fragment[begin_index].flags = 0;
-               this_fragmentation->fragment[begin_index].length = 0;
-                begin_index = (begin_index + 1) & MAXFRAGNUM_MASK;
-        }

 
 

-       LOG(4, s, t, "MPPP after assembling: M index is =%d, start index is = %d, start seq=%d\n",M_index, this_fragmentation->start_index, this_fragmentation->start_seq);     

        return;
 }
 
        return;
 }
 


@@ -2371,7 +2560,7 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid
 
        if ((b - start) + l > size)
        {
 
        if ((b - start) + l > size)
        {

-               LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, (b - start) + l);
+               LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%td)\n", size, (b - start) + l);

                return NULL;
        }
 
                return NULL;
        }