if.c revision dc3c1d295bdf59ab52692f78315a664673bf3f2c
/*
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include <slirp.h>
{
}
{
}
void
{
#if 0
/*
* and 8 bytes for PPP, but need to have it on an 8byte boundary
*/
#ifdef USE_PPP
if_maxlinkhdr = 48;
#else
if_maxlinkhdr = 40;
#endif
#else
#endif
if_queued = 0;
if_thresh = 10;
if_mtu = 1500;
if_mru = 1500;
/* sl_compress_init(&comp_s); */
}
/*
* if_output: Queue packet into an output queue.
* There are 2 output queue's, if_fastq and if_batchq.
* Each output queue is a doubly linked list of double linked lists
* of mbufs, each list belonging to one "session" (socket). This
* way, we can output packets fairly by sending one packet from each
* session, instead of all the packets from one session, then all packets
* from the next session, etc. Packets on the if_fastq get absolute
* priority, but if one session hogs the link, it gets "downgraded"
* to the batchq until it runs out of packets, then it'll return
* to the fastq (eg. if the user does an ls -alR in a telnet session,
* it'll temporarily get downgraded to the batchq)
*/
void
{
int on_fastq = 1;
DEBUG_CALL("if_output");
/*
* First remove the mbuf from m_usedlist,
* since we're gonna use m_next and m_prev ourselves
* XXX Shouldn't need this, gotta change dtom() etc.
*/
}
/*
* See if there's already a batchq list for this session.
* This can include an interactive session, which should go on fastq,
* but gets too greedy... hence it'll be downgraded from fastq to batchq.
* We mustn't put this packet back on the fastq (or we'll send it out of order)
* XXX add cache here?
*/
/* A match! */
goto diddit;
}
}
/* No match, check which queue to put it on */
on_fastq = 1;
/*
* Check if this packet is a part of the last
* packet's session
*/
goto diddit;
}
} else
/* Create a new doubly linked list for this session */
++if_queued;
if (so) {
/* Update *_queued */
so->so_nqueued++;
/*
* Check if the interactive session should be downgraded to
* the batchq. A session is downgraded if it has queued 6
* packets without pausing, and at least 3 of those packets
* have been sent over the link
* (XXX These are arbitrary numbers, probably not optimal..)
*/
/* Remove from current queue... */
/* ...And insert in the new. That'll teach ya! */
}
}
#ifndef FULL_BOLT
/*
* This prevents us from malloc()ing too many mbufs
*/
if (link_up) {
/* if_start will check towrite */
}
#endif
}
/*
* Send a packet
* We choose a packet based on it's position in the output queues;
* If there are packets on the fastq, they are sent FIFO, before
* everything else. Otherwise we choose the first packet from the
* batchq and send it. the next packet chosen will be from the session
* after this one, then the session after that one, and so on.. So,
* for example, if there are 3 ftp session's fighting for bandwidth,
* one packet will be sent from the first session, then one packet
* from the second session, then one packet from the third, then back
* to the first, etc. etc.
*/
void
{
DEBUG_CALL("if_start");
if (if_queued == 0)
return; /* Nothing to do */
/* check if we can really output */
return;
/*
* See which queue to get next packet from
* If there's something in the fastq, select it immediately
*/
} else {
/* Nothing on fastq, see if next_m is valid */
else
/* Set which packet to send on next iteration */
}
/* Remove it from the queue */
--if_queued;
/* If there are more packets for this session, re-queue them */
}
/* Update so_queued */
/* If there's no more queued, reset nqueued */
}
/* Encapsulate the packet for sending */
if (if_queued)
goto again;
}