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l2tplac: Delay considering the tunnel to LNS open until SCCCN ack

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We are not really supposed to send ICRQ until we got our SCCCN acked, so better
wait for it.
This commit is contained in:
Samuel Thibault 2025-03-09 17:48:28 +01:00
parent 6f04a5c390
commit b48dfb2697
2 changed files with 18 additions and 5 deletions
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22
l2tpns.c
View file

@ -3483,14 +3483,15 @@ static void controlnull(tunnelidt t)
}
// add a control message to a tunnel, and send if within window
static void controladd(controlt *c, sessionidt far, tunnelidt t)
static uint16_t controladd(controlt *c, sessionidt far, tunnelidt t)
{
uint16_t *pint16 = (uint16_t *) (c->buf + 2);
uint16_t ns;
pint16[0] = htons(c->length); // length
pint16[1] = htons(tunnel[t].far); // tunnel
pint16[2] = htons(far); // session
pint16[3] = htons(tunnel[t].ns); // sequence
tunnel[t].ns++; // advance sequence
ns = tunnel[t].ns++; // advance sequence
pint16[3] = htons(ns); // sequence
// link in message in to queue
if (tunnel[t].controlc)
tunnel[t].controle->next = c;
@ -3506,6 +3507,7 @@ static void controladd(controlt *c, sessionidt far, tunnelidt t)
tunnel[t].try = 0; // first send
tunnelsend(c->buf, c->length, t);
}
return ns;
}
//
@ -3904,6 +3906,7 @@ static void tunnelclear(tunnelidt t)
tunn_local[t].l2tp_fd = -1;
tunnel[t].state = TUNNELFREE;
tunn_local[t].scccn = -1;
}
static void bundleclear(bundleidt b)
@ -4279,6 +4282,15 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr, uint16_t indexu
if (!tunnel[t].controlc)
tunnel[t].retry = 0; // caught up
}
{
// Handle ack (possibly just a ZLB)
if (tunn_local[t].scccn >= 0 && ((uint16_t) tunn_local[t].scccn) - nr >= 0x8000u)
{
LOG(3, s, t, "REMOTE LNS acked our SCCCN %d\n", tunn_local[t].scccn);
tunn_local[t].scccn = -1;
tunnel[t].state = TUNNELOPEN;
}
}
if (l)
{ // if not a null message
int result = 0;
@ -4750,7 +4762,6 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr, uint16_t indexu
}
break;
case 2: // SCCRP
tunnel[t].state = TUNNELOPEN;
tunnel[t].lastrec = time_now;
LOG(3, s, t, "Received SCCRP\n");
if (main_quit != QUIT_SHUTDOWN)
@ -4772,7 +4783,8 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr, uint16_t indexu
control32(c, 3, 3, 1); // framing Capabilities
if (sendchalresponse) controlb(c, 13, sendchalresponse, 16, 1); // Challenge response
control16(c, 9, t, 1); // assigned tunnel
controladd(c, 0, t); // send
tunn_local[t].scccn = controladd(c, 0, t); // send
LOG(3, s, t, "sent SCCCN as %d\n", tunn_local[t].scccn);
}
else
{

1
l2tpns.h
View file

@ -517,6 +517,7 @@ tunnelt;
typedef struct
{
int32_t scccn; // seq number of last sccn waiting for an ack (-1 if none)
controlt *controlr; // queue of OoO-received messages
int l2tp_fd; // kernel acceleration UDP socket
}