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Fix MLPPP functionality.

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Fernando Alves 2012-02-03 16:28:14 +01:00 • committed by Benjamin Cama
parent 6dfe2883c9
commit 442b04cea2
4 changed files with 405 additions and 155 deletions
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405
ppp.c
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@ -1809,130 +1809,299 @@ 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)
{
bundleidt b = session[s].bundle;
bundleidt b = session[s].bundle;
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);
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;
uint16_t begin_index, end_index;
uint16_t begin_index, end_index, start_index;
// 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
/* 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);
}
max_seq = this_bundle->max_seq;
maskSeq = max_seq - 1;
/*
* 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 = (seq_num + this_bundle->max_seq - this_fragmentation->start_seq) & (this_bundle->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;
}
frag_offset = (int) (seq_num - this_fragmentation->start_seq);
start_index = this_fragmentation->start_index;
// update M
sess_local[s].last_seq = seq_num;
uint32_t min;
if (seq_num < this_fragmentation->M)
{
min = seq_num;
this_fragmentation->M = seq_num;
}
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++)
{
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;
}
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;
//caculate M's index in the fragment array
M_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)
{
if (begin_frame)
{
// Set new Start sequence
this_fragmentation->start_index = begin_index;
this_fragmentation->start_seq = min;
frag_offset = 0;
}
}
else
{
// 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--;
}
// 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;
//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];
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;
memcpy(this_frag->data, p, l);
memcpy(this_frag->data, p, l);
// 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)
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)
{
if (this_fragmentation->fragment[begin_index].flags & MP_BEGIN)
break;
begin_index = (begin_index ? (begin_index -1) : (MAXFRAGNUM -1));
// 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
}
}
// return if a lost fragment is found
if (!(this_fragmentation->fragment[begin_index].length))
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
begin_index = end_index = this_fragmentation->start_index;
if (this_fragmentation->fragment[begin_index].length)
{
if (!(this_fragmentation->fragment[begin_index].flags & MP_BEGIN))
return; // assembling frame failed
}
else
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;
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
@ -1942,35 +2111,37 @@ 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
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)
{
{
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);
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;
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;
}
}
// 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
@ -1978,20 +2149,32 @@ void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
if (i == end_index)
break;
}
}
//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);
// 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;
}
}
}
return;
}
@ -2373,7 +2556,7 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid
if ((b - start) + l > size)
{
LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%ld)\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;
}