mirror of
https://github.com/qemu/qemu.git
synced 2024-12-05 17:53:36 +08:00
02d2c54cd3
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1102 c046a42c-6fe2-441c-8c8c-71466251a162
323 lines
7.7 KiB
C
323 lines
7.7 KiB
C
/*
|
|
* Copyright (c) 1995 Danny Gasparovski.
|
|
*
|
|
* Please read the file COPYRIGHT for the
|
|
* terms and conditions of the copyright.
|
|
*/
|
|
|
|
#include <slirp.h>
|
|
|
|
int if_mtu, if_mru;
|
|
int if_comp;
|
|
int if_maxlinkhdr;
|
|
int if_queued = 0; /* Number of packets queued so far */
|
|
int if_thresh = 10; /* Number of packets queued before we start sending
|
|
* (to prevent allocing too many mbufs) */
|
|
|
|
struct mbuf if_fastq; /* fast queue (for interactive data) */
|
|
struct mbuf if_batchq; /* queue for non-interactive data */
|
|
struct mbuf *next_m; /* Pointer to next mbuf to output */
|
|
|
|
#define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
|
|
|
|
void
|
|
ifs_insque(ifm, ifmhead)
|
|
struct mbuf *ifm, *ifmhead;
|
|
{
|
|
ifm->ifs_next = ifmhead->ifs_next;
|
|
ifmhead->ifs_next = ifm;
|
|
ifm->ifs_prev = ifmhead;
|
|
ifm->ifs_next->ifs_prev = ifm;
|
|
}
|
|
|
|
void
|
|
ifs_remque(ifm)
|
|
struct mbuf *ifm;
|
|
{
|
|
ifm->ifs_prev->ifs_next = ifm->ifs_next;
|
|
ifm->ifs_next->ifs_prev = ifm->ifs_prev;
|
|
}
|
|
|
|
void
|
|
if_init()
|
|
{
|
|
#if 0
|
|
/*
|
|
* Set if_maxlinkhdr to 48 because it's 40 bytes for TCP/IP,
|
|
* 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
|
|
/* 14 for ethernet + 40 */
|
|
if_maxlinkhdr = 14 + 40;
|
|
#endif
|
|
if_mtu = 1500;
|
|
if_mru = 1500;
|
|
if_comp = IF_AUTOCOMP;
|
|
if_fastq.ifq_next = if_fastq.ifq_prev = &if_fastq;
|
|
if_batchq.ifq_next = if_batchq.ifq_prev = &if_batchq;
|
|
// sl_compress_init(&comp_s);
|
|
next_m = &if_batchq;
|
|
}
|
|
|
|
#if 0
|
|
/*
|
|
* This shouldn't be needed since the modem is blocking and
|
|
* we don't expect any signals, but what the hell..
|
|
*/
|
|
inline int
|
|
writen(fd, bptr, n)
|
|
int fd;
|
|
char *bptr;
|
|
int n;
|
|
{
|
|
int ret;
|
|
int total;
|
|
|
|
/* This should succeed most of the time */
|
|
ret = send(fd, bptr, n,0);
|
|
if (ret == n || ret <= 0)
|
|
return ret;
|
|
|
|
/* Didn't write everything, go into the loop */
|
|
total = ret;
|
|
while (n > total) {
|
|
ret = send(fd, bptr+total, n-total,0);
|
|
if (ret <= 0)
|
|
return ret;
|
|
total += ret;
|
|
}
|
|
return total;
|
|
}
|
|
|
|
/*
|
|
* if_input - read() the tty, do "top level" processing (ie: check for any escapes),
|
|
* and pass onto (*ttyp->if_input)
|
|
*
|
|
* XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet.
|
|
*/
|
|
#define INBUFF_SIZE 2048 /* XXX */
|
|
void
|
|
if_input(ttyp)
|
|
struct ttys *ttyp;
|
|
{
|
|
u_char if_inbuff[INBUFF_SIZE];
|
|
int if_n;
|
|
|
|
DEBUG_CALL("if_input");
|
|
DEBUG_ARG("ttyp = %lx", (long)ttyp);
|
|
|
|
if_n = recv(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE,0);
|
|
|
|
DEBUG_MISC((dfd, " read %d bytes\n", if_n));
|
|
|
|
if (if_n <= 0) {
|
|
if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) {
|
|
if (ttyp->up)
|
|
link_up--;
|
|
tty_detached(ttyp, 0);
|
|
}
|
|
return;
|
|
}
|
|
if (if_n == 1) {
|
|
if (*if_inbuff == '0') {
|
|
ttyp->ones = 0;
|
|
if (++ttyp->zeros >= 5)
|
|
slirp_exit(0);
|
|
return;
|
|
}
|
|
if (*if_inbuff == '1') {
|
|
ttyp->zeros = 0;
|
|
if (++ttyp->ones >= 5)
|
|
tty_detached(ttyp, 0);
|
|
return;
|
|
}
|
|
}
|
|
ttyp->ones = ttyp->zeros = 0;
|
|
|
|
(*ttyp->if_input)(ttyp, if_inbuff, if_n);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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
|
|
if_output(so, ifm)
|
|
struct socket *so;
|
|
struct mbuf *ifm;
|
|
{
|
|
struct mbuf *ifq;
|
|
int on_fastq = 1;
|
|
|
|
DEBUG_CALL("if_output");
|
|
DEBUG_ARG("so = %lx", (long)so);
|
|
DEBUG_ARG("ifm = %lx", (long)ifm);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (ifm->m_flags & M_USEDLIST) {
|
|
remque(ifm);
|
|
ifm->m_flags &= ~M_USEDLIST;
|
|
}
|
|
|
|
/*
|
|
* 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?
|
|
*/
|
|
for (ifq = if_batchq.ifq_prev; ifq != &if_batchq; ifq = ifq->ifq_prev) {
|
|
if (so == ifq->ifq_so) {
|
|
/* A match! */
|
|
ifm->ifq_so = so;
|
|
ifs_insque(ifm, ifq->ifs_prev);
|
|
goto diddit;
|
|
}
|
|
}
|
|
|
|
/* No match, check which queue to put it on */
|
|
if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
|
|
ifq = if_fastq.ifq_prev;
|
|
on_fastq = 1;
|
|
/*
|
|
* Check if this packet is a part of the last
|
|
* packet's session
|
|
*/
|
|
if (ifq->ifq_so == so) {
|
|
ifm->ifq_so = so;
|
|
ifs_insque(ifm, ifq->ifs_prev);
|
|
goto diddit;
|
|
}
|
|
} else
|
|
ifq = if_batchq.ifq_prev;
|
|
|
|
/* Create a new doubly linked list for this session */
|
|
ifm->ifq_so = so;
|
|
ifs_init(ifm);
|
|
insque(ifm, ifq);
|
|
|
|
diddit:
|
|
++if_queued;
|
|
|
|
if (so) {
|
|
/* Update *_queued */
|
|
so->so_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..)
|
|
*/
|
|
if (on_fastq && ((so->so_nqueued >= 6) &&
|
|
(so->so_nqueued - so->so_queued) >= 3)) {
|
|
|
|
/* Remove from current queue... */
|
|
remque(ifm->ifs_next);
|
|
|
|
/* ...And insert in the new. That'll teach ya! */
|
|
insque(ifm->ifs_next, &if_batchq);
|
|
}
|
|
}
|
|
|
|
#ifndef FULL_BOLT
|
|
/*
|
|
* This prevents us from malloc()ing too many mbufs
|
|
*/
|
|
if (link_up) {
|
|
/* if_start will check towrite */
|
|
if_start();
|
|
}
|
|
#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
|
|
if_start(void)
|
|
{
|
|
struct mbuf *ifm, *ifqt;
|
|
|
|
DEBUG_CALL("if_start");
|
|
|
|
if (if_queued == 0)
|
|
return; /* Nothing to do */
|
|
|
|
again:
|
|
/* check if we can really output */
|
|
if (!slirp_can_output())
|
|
return;
|
|
|
|
/*
|
|
* See which queue to get next packet from
|
|
* If there's something in the fastq, select it immediately
|
|
*/
|
|
if (if_fastq.ifq_next != &if_fastq) {
|
|
ifm = if_fastq.ifq_next;
|
|
} else {
|
|
/* Nothing on fastq, see if next_m is valid */
|
|
if (next_m != &if_batchq)
|
|
ifm = next_m;
|
|
else
|
|
ifm = if_batchq.ifq_next;
|
|
|
|
/* Set which packet to send on next iteration */
|
|
next_m = ifm->ifq_next;
|
|
}
|
|
/* Remove it from the queue */
|
|
ifqt = ifm->ifq_prev;
|
|
remque(ifm);
|
|
--if_queued;
|
|
|
|
/* If there are more packets for this session, re-queue them */
|
|
if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) {
|
|
insque(ifm->ifs_next, ifqt);
|
|
ifs_remque(ifm);
|
|
}
|
|
|
|
/* Update so_queued */
|
|
if (ifm->ifq_so) {
|
|
if (--ifm->ifq_so->so_queued == 0)
|
|
/* If there's no more queued, reset nqueued */
|
|
ifm->ifq_so->so_nqueued = 0;
|
|
}
|
|
|
|
/* Encapsulate the packet for sending */
|
|
if_encap(ifm->m_data, ifm->m_len);
|
|
|
|
m_free(ifm);
|
|
|
|
if (if_queued)
|
|
goto again;
|
|
}
|