ref: 61f4c085c402af665b436f6d010d61107551d8a3
dir: /sys/src/9/ip/il.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
#include "ip.h"
enum /* Connection state */
{
Ilclosed,
Ilsyncer,
Ilsyncee,
Ilestablished,
Illistening,
Ilclosing,
Ilopening, /* only for file server */
};
char *ilstates[] =
{
"Closed",
"Syncer",
"Syncee",
"Established",
"Listen",
"Closing",
"Opening", /* only for file server */
};
enum /* Packet types */
{
Ilsync,
Ildata,
Ildataquery,
Ilack,
Ilquery,
Ilstate,
Ilclose,
};
char *iltype[] =
{
"sync",
"data",
"dataquery",
"ack",
"query",
"state",
"close"
};
enum
{
Seconds = 1000,
Iltickms = 50, /* time base */
AckDelay = 2*Iltickms, /* max time twixt message rcvd & ack sent */
MaxTimeout = 30*Seconds, /* max time between rexmit */
QueryTime = 10*Seconds, /* time between subsequent queries */
DeathTime = 30*QueryTime,
MaxRexmit = 16, /* max retransmissions before hangup */
Defaultwin = 20,
LogAGain = 3,
AGain = 1<<LogAGain,
LogDGain = 2,
DGain = 1<<LogDGain,
DefByteRate = 100, /* assume a megabit link */
DefRtt = 50, /* cross country on a great day */
Maxrq = 64*1024,
};
enum
{
Nqt= 8,
};
typedef struct Ilcb Ilcb;
struct Ilcb /* Control block */
{
int state; /* Connection state */
Conv *conv;
QLock ackq; /* Unacknowledged queue */
Block *unacked;
Block *unackedtail;
ulong unackedbytes;
QLock outo; /* Out of order packet queue */
Block *outoforder;
ulong next; /* Id of next to send */
ulong recvd; /* Last packet received */
ulong acksent; /* Last packet acked */
ulong start; /* Local start id */
ulong rstart; /* Remote start id */
int window; /* Maximum receive window */
int rxquery; /* number of queries on this connection */
int rxtot; /* number of retransmits on this connection */
int rexmit; /* number of retransmits of *unacked */
ulong qt[Nqt+1]; /* state table for query messages */
int qtx; /* ... index into qt */
/* if set, fasttimeout causes a connection request to terminate after 4*Iltickms */
int fasttimeout;
/* timers */
ulong lastxmit; /* time of last xmit */
ulong lastrecv; /* time of last recv */
ulong timeout; /* retransmission time for *unacked */
ulong acktime; /* time to send next ack */
ulong querytime; /* time to send next query */
/* adaptive measurements */
int delay; /* Average of the fixed rtt delay */
int rate; /* Average uchar rate */
int mdev; /* Mean deviation of rtt */
int maxrtt; /* largest rtt seen */
ulong rttack; /* The ack we are waiting for */
int rttlen; /* Length of rttack packet */
uvlong rttstart; /* Time we issued rttack packet */
};
enum
{
IL_IPSIZE = 20,
IL_HDRSIZE = 18,
IL_LISTEN = 0,
IL_CONNECT = 1,
IP_ILPROTO = 40,
};
typedef struct Ilhdr Ilhdr;
struct Ilhdr
{
uchar vihl; /* Version and header length */
uchar tos; /* Type of service */
uchar length[2]; /* packet length */
uchar id[2]; /* Identification */
uchar frag[2]; /* Fragment information */
uchar ttl; /* Time to live */
uchar proto; /* Protocol */
uchar cksum[2]; /* Header checksum */
uchar src[4]; /* Ip source */
uchar dst[4]; /* Ip destination */
uchar ilsum[2]; /* Checksum including header */
uchar illen[2]; /* Packet length */
uchar iltype; /* Packet type */
uchar ilspec; /* Special */
uchar ilsrc[2]; /* Src port */
uchar ildst[2]; /* Dst port */
uchar ilid[4]; /* Sequence id */
uchar ilack[4]; /* Acked sequence */
};
enum
{
InMsgs,
OutMsgs,
CsumErrs, /* checksum errors */
HlenErrs, /* header length error */
LenErrs, /* short packet */
OutOfOrder, /* out of order */
Retrans, /* retransmissions */
DupMsg,
DupBytes,
DroppedMsgs,
Nstats,
};
static char *statnames[] =
{
[InMsgs] "InMsgs",
[OutMsgs] "OutMsgs",
[CsumErrs] "CsumErrs",
[HlenErrs] "HlenErr",
[LenErrs] "LenErrs",
[OutOfOrder] "OutOfOrder",
[Retrans] "Retrans",
[DupMsg] "DupMsg",
[DupBytes] "DupBytes",
[DroppedMsgs] "DroppedMsgs",
};
typedef struct Ilpriv Ilpriv;
struct Ilpriv
{
Ipht ht;
uvlong stats[Nstats];
ulong csumerr; /* checksum errors */
ulong hlenerr; /* header length error */
ulong lenerr; /* short packet */
ulong order; /* out of order */
ulong rexmit; /* retransmissions */
ulong dup;
ulong dupb;
/* keeping track of the ack kproc */
int ackprocstarted;
QLock apl;
};
/* state for query/dataquery messages */
void ilrcvmsg(Conv*, Block*);
int ilsendctl(Conv*, Ilhdr*, int, ulong, ulong, int);
void ilackq(Ilcb*, Block*);
void ilprocess(Conv*, Ilhdr*, Block*);
void ilpullup(Conv*);
void ilhangup(Conv*, char*);
void ilfreeq(Ilcb*);
void ilrexmit(Ilcb*);
void ilbackoff(Ilcb*);
void ilsettimeout(Ilcb*);
char* ilstart(Conv*, int, int);
void ilackproc(void*);
void iloutoforder(Conv*, Ilhdr*, Block*);
void iliput(Proto*, Ipifc*, Block*);
void iladvise(Proto*, Block*, Ipifc*, char*);
int ilnextqt(Ilcb*);
void ilcbinit(Ilcb*);
int later(ulong, ulong, char*);
void ilreject(Fs*, Ilhdr*);
void illocalclose(Conv *c);
int ilcksum = 1;
static int initseq = 25001;
static ulong scalediv, scalemul;
static char *etime = "connection timed out";
static char*
ilconnect(Conv *c, char **argv, int argc)
{
char *e, *p;
int fast;
/* huge hack to quickly try an il connection */
fast = 0;
if(argc > 1){
p = strstr(argv[1], "!fasttimeout");
if(p != nil){
*p = 0;
fast = 1;
}
}
e = Fsstdconnect(c, argv, argc);
if(e != nil)
return e;
if(c->ipversion != V4)
return "only IP version 4 supported";
return ilstart(c, IL_CONNECT, fast);
}
static int
ilstate(Conv *c, char *state, int n)
{
Ilcb *ic;
ic = (Ilcb*)(c->ptcl);
return snprint(state, n, "%s qin %d qout %d del %5.5d Br %5.5d md %5.5d una %5.5lud rex %5.5d rxq %5.5d max %5.5d\n",
ilstates[ic->state],
c->rq ? qlen(c->rq) : 0,
c->wq ? qlen(c->wq) : 0,
ic->delay>>LogAGain, ic->rate>>LogAGain, ic->mdev>>LogDGain,
ic->unackedbytes, ic->rxtot, ic->rxquery, ic->maxrtt);
}
static int
ilinuse(Conv *c)
{
Ilcb *ic;
ic = (Ilcb*)(c->ptcl);
return ic->state != Ilclosed;
}
/* called with c locked */
static char*
ilannounce(Conv *c, char **argv, int argc)
{
char *e;
e = Fsstdannounce(c, argv, argc);
if(e != nil)
return e;
e = ilstart(c, IL_LISTEN, 0);
if(e != nil)
return e;
Fsconnected(c, nil);
return nil;
}
void
illocalclose(Conv *c)
{
Ilcb *ic;
Ilpriv *ipriv;
ipriv = c->p->priv;
ic = (Ilcb*)c->ptcl;
ic->state = Ilclosed;
iphtrem(&ipriv->ht, c);
c->lport = 0;
ipmove(c->laddr, IPnoaddr);
}
static void
ilclose(Conv *c)
{
Ilcb *ic;
ic = (Ilcb*)c->ptcl;
qclose(c->rq);
qclose(c->wq);
qclose(c->eq);
switch(ic->state) {
case Ilclosing:
case Ilclosed:
break;
case Ilsyncer:
case Ilsyncee:
case Ilestablished:
ic->state = Ilclosing;
ilsettimeout(ic);
ilsendctl(c, nil, Ilclose, ic->next, ic->recvd, 0);
break;
case Illistening:
illocalclose(c);
break;
}
ilfreeq(ic);
}
void
ilkick(void *x, Block *bp)
{
Conv *c = x;
Ilhdr *ih;
Ilcb *ic;
int dlen;
ulong id, ack;
Fs *f;
Ilpriv *priv;
f = c->p->f;
priv = c->p->priv;
ic = (Ilcb*)c->ptcl;
if(bp == nil)
return;
switch(ic->state) {
case Ilclosed:
case Illistening:
case Ilclosing:
freeblist(bp);
qhangup(c->rq, nil);
return;
}
dlen = blocklen(bp);
/* Make space to fit il & ip */
bp = padblock(bp, IL_IPSIZE+IL_HDRSIZE);
ih = (Ilhdr *)(bp->rp);
ih->vihl = IP_VER4;
/* Ip fields */
ih->frag[0] = 0;
ih->frag[1] = 0;
v6tov4(ih->dst, c->raddr);
v6tov4(ih->src, c->laddr);
ih->proto = IP_ILPROTO;
/* Il fields */
hnputs(ih->illen, dlen+IL_HDRSIZE);
hnputs(ih->ilsrc, c->lport);
hnputs(ih->ildst, c->rport);
qlock(&ic->ackq);
id = ic->next++;
hnputl(ih->ilid, id);
ack = ic->recvd;
hnputl(ih->ilack, ack);
ic->acksent = ack;
ic->acktime = NOW + AckDelay;
ih->iltype = Ildata;
ih->ilspec = 0;
ih->ilsum[0] = 0;
ih->ilsum[1] = 0;
/* Checksum of ilheader plus data (not ip & no pseudo header) */
if(ilcksum)
hnputs(ih->ilsum, ptclcsum(bp, IL_IPSIZE, dlen+IL_HDRSIZE));
ilackq(ic, bp);
qunlock(&ic->ackq);
/* Start the round trip timer for this packet if the timer is free */
if(ic->rttack == 0) {
ic->rttack = id;
ic->rttstart = fastticks(nil);
ic->rttlen = dlen + IL_IPSIZE + IL_HDRSIZE;
}
if(later(NOW, ic->timeout, nil))
ilsettimeout(ic);
ipoput4(f, bp, nil, c->ttl, c->tos, c);
priv->stats[OutMsgs]++;
}
static void
ilcreate(Conv *c)
{
c->rq = qopen(Maxrq, 0, 0, c);
c->wq = qbypass(ilkick, c);
}
int
ilxstats(Proto *il, char *buf, int len)
{
Ilpriv *priv;
char *p, *e;
int i;
priv = il->priv;
p = buf;
e = p+len;
for(i = 0; i < Nstats; i++)
p = seprint(p, e, "%s: %llud\n", statnames[i], priv->stats[i]);
return p - buf;
}
void
ilackq(Ilcb *ic, Block *bp)
{
Block *np;
int n;
n = blocklen(bp);
/* Enqueue a copy on the unacked queue in case this one gets lost */
np = copyblock(bp, n);
if(ic->unacked)
ic->unackedtail->list = np;
else
ic->unacked = np;
ic->unackedtail = np;
np->list = nil;
ic->unackedbytes += n;
}
static
void
ilrttcalc(Ilcb *ic, Block *bp)
{
int rtt, tt, pt, delay, rate;
rtt = fastticks(nil) - ic->rttstart;
rtt = (rtt*scalemul)/scalediv;
delay = ic->delay;
rate = ic->rate;
/* Guard against zero wrap */
if(rtt > 120000 || rtt < 0)
return;
/* this block had to be transmitted after the one acked so count its size */
ic->rttlen += blocklen(bp) + IL_IPSIZE + IL_HDRSIZE;
if(ic->rttlen < 256){
/* guess fixed delay as rtt of small packets */
delay += rtt - (delay>>LogAGain);
if(delay < AGain)
delay = AGain;
ic->delay = delay;
} else {
/* if packet took longer than avg rtt delay, recalc rate */
tt = rtt - (delay>>LogAGain);
if(tt > 0){
rate += ic->rttlen/tt - (rate>>LogAGain);
if(rate < AGain)
rate = AGain;
ic->rate = rate;
}
}
/* mdev */
pt = ic->rttlen/(rate>>LogAGain) + (delay>>LogAGain);
ic->mdev += abs(rtt-pt) - (ic->mdev>>LogDGain);
if(rtt > ic->maxrtt)
ic->maxrtt = rtt;
}
void
ilackto(Ilcb *ic, ulong ackto, Block *bp)
{
Ilhdr *h;
ulong id;
if(ic->rttack == ackto)
ilrttcalc(ic, bp);
/* Cancel if we've passed the packet we were interested in */
if(ic->rttack <= ackto)
ic->rttack = 0;
qlock(&ic->ackq);
while(ic->unacked) {
h = (Ilhdr *)ic->unacked->rp;
id = nhgetl(h->ilid);
if(ackto < id)
break;
bp = ic->unacked;
ic->unacked = bp->list;
bp->list = nil;
ic->unackedbytes -= blocklen(bp);
freeblist(bp);
ic->rexmit = 0;
ilsettimeout(ic);
}
qunlock(&ic->ackq);
}
void
iliput(Proto *il, Ipifc*, Block *bp)
{
char *st;
Ilcb *ic;
Ilhdr *ih;
uchar raddr[IPaddrlen];
uchar laddr[IPaddrlen];
ushort sp, dp, csum;
int plen, illen;
Iphash *iph;
Conv *new, *s;
Ilpriv *ipriv;
ipriv = il->priv;
ih = (Ilhdr *)bp->rp;
plen = blocklen(bp);
if(plen > 0 && (ih->vihl&0xF0)!=IP_VER4)
goto raise; /* ignore non V4 packets */
if(plen < IL_IPSIZE+IL_HDRSIZE){
netlog(il->f, Logil, "il: hlenerr\n");
ipriv->stats[HlenErrs]++;
goto raise;
}
illen = nhgets(ih->illen);
if(illen+IL_IPSIZE > plen){
netlog(il->f, Logil, "il: lenerr\n");
ipriv->stats[LenErrs]++;
goto raise;
}
sp = nhgets(ih->ildst);
dp = nhgets(ih->ilsrc);
v4tov6(raddr, ih->src);
v4tov6(laddr, ih->dst);
if((csum = ptclcsum(bp, IL_IPSIZE, illen)) != 0) {
if(ih->iltype > Ilclose)
st = "?";
else
st = iltype[ih->iltype];
ipriv->stats[CsumErrs]++;
netlog(il->f, Logil, "il: cksum %ux %s, pkt(%ux id %ud ack %I/%d->%d)\n",
csum, st, nhgetl(ih->ilid), nhgetl(ih->ilack), raddr, sp, dp);
goto raise;
}
qlock(il);
iph = iphtlook(&ipriv->ht, raddr, dp, laddr, sp);
if(iph == nil){
if(ih->iltype == Ilsync)
ilreject(il->f, ih); /* no listener */
qunlock(il);
goto raise;
}
s = iphconv(iph);
ic = (Ilcb*)s->ptcl;
if(ic->state == Illistening){
if(ih->iltype != Ilsync){
qunlock(il);
if(ih->iltype > Ilclose)
st = "?";
else
st = iltype[ih->iltype];
ilreject(il->f, ih); /* no channel and not sync */
netlog(il->f, Logil, "il: no channel, pkt(%s id %ud ack %ud %I/%ud->%ud)\n",
st, nhgetl(ih->ilid), nhgetl(ih->ilack), raddr, sp, dp);
goto raise;
}
new = Fsnewcall(s, raddr, dp, laddr, sp, V4);
if(new == nil){
qunlock(il);
netlog(il->f, Logil, "il: bad newcall %I/%ud->%ud\n", raddr, sp, dp);
ilsendctl(s, ih, Ilclose, 0, nhgetl(ih->ilid), 0);
goto raise;
}
s = new;
ic = (Ilcb*)s->ptcl;
ic->conv = s;
ic->state = Ilsyncee;
ilcbinit(ic);
ic->rstart = nhgetl(ih->ilid);
iphtadd(&ipriv->ht, s);
}
qlock(s);
qunlock(il);
if(waserror()){
qunlock(s);
nexterror();
}
ilprocess(s, ih, bp);
qunlock(s);
poperror();
return;
raise:
freeblist(bp);
}
void
_ilprocess(Conv *s, Ilhdr *h, Block *bp)
{
Ilcb *ic;
ulong id, ack;
Ilpriv *priv;
id = nhgetl(h->ilid);
ack = nhgetl(h->ilack);
ic = (Ilcb*)s->ptcl;
ic->lastrecv = NOW;
ic->querytime = NOW + QueryTime;
priv = s->p->priv;
priv->stats[InMsgs]++;
switch(ic->state) {
default:
netlog(s->p->f, Logil, "il: unknown state %d\n", ic->state);
case Ilclosed:
freeblist(bp);
break;
case Ilsyncer:
switch(h->iltype) {
default:
break;
case Ilsync:
if(ack != ic->start)
ilhangup(s, "connection rejected");
else {
ic->recvd = id;
ic->rstart = id;
ilsendctl(s, nil, Ilack, ic->next, ic->recvd, 0);
ic->state = Ilestablished;
ic->fasttimeout = 0;
ic->rexmit = 0;
Fsconnected(s, nil);
ilpullup(s);
}
break;
case Ilclose:
if(ack == ic->start)
ilhangup(s, "connection rejected");
break;
}
freeblist(bp);
break;
case Ilsyncee:
switch(h->iltype) {
default:
break;
case Ilsync:
if(id != ic->rstart || ack != 0){
illocalclose(s);
} else {
ic->recvd = id;
ilsendctl(s, nil, Ilsync, ic->start, ic->recvd, 0);
}
break;
case Ilack:
if(ack == ic->start) {
ic->state = Ilestablished;
ic->fasttimeout = 0;
ic->rexmit = 0;
ilpullup(s);
}
break;
case Ildata:
if(ack == ic->start) {
ic->state = Ilestablished;
ic->fasttimeout = 0;
ic->rexmit = 0;
goto established;
}
break;
case Ilclose:
if(ack == ic->start)
ilhangup(s, "remote close");
break;
}
freeblist(bp);
break;
case Ilestablished:
established:
switch(h->iltype) {
case Ilsync:
if(id != ic->rstart)
ilhangup(s, "remote close");
else
ilsendctl(s, nil, Ilack, ic->next, ic->rstart, 0);
freeblist(bp);
break;
case Ildata:
/*
* avoid consuming all the mount rpc buffers in the
* system. if the input queue is too long, drop this
* packet.
*/
if (s->rq && qlen(s->rq) >= Maxrq) {
priv->stats[DroppedMsgs]++;
freeblist(bp);
break;
}
ilackto(ic, ack, bp);
iloutoforder(s, h, bp);
ilpullup(s);
break;
case Ildataquery:
ilackto(ic, ack, bp);
iloutoforder(s, h, bp);
ilpullup(s);
ilsendctl(s, nil, Ilstate, ic->next, ic->recvd, h->ilspec);
break;
case Ilack:
ilackto(ic, ack, bp);
freeblist(bp);
break;
case Ilquery:
ilackto(ic, ack, bp);
ilsendctl(s, nil, Ilstate, ic->next, ic->recvd, h->ilspec);
freeblist(bp);
break;
case Ilstate:
if(ack >= ic->rttack)
ic->rttack = 0;
ilackto(ic, ack, bp);
if(h->ilspec > Nqt)
h->ilspec = 0;
if(ic->qt[h->ilspec] > ack){
ilrexmit(ic);
ilsettimeout(ic);
}
freeblist(bp);
break;
case Ilclose:
freeblist(bp);
if(ack < ic->start || ack > ic->next)
break;
ic->recvd = id;
ilsendctl(s, nil, Ilclose, ic->next, ic->recvd, 0);
ic->state = Ilclosing;
ilsettimeout(ic);
ilfreeq(ic);
break;
}
break;
case Illistening:
freeblist(bp);
break;
case Ilclosing:
switch(h->iltype) {
case Ilclose:
ic->recvd = id;
ilsendctl(s, nil, Ilclose, ic->next, ic->recvd, 0);
if(ack == ic->next)
ilhangup(s, nil);
break;
default:
break;
}
freeblist(bp);
break;
}
}
void
ilrexmit(Ilcb *ic)
{
Ilhdr *h;
Block *nb;
Conv *c;
ulong id;
Ilpriv *priv;
nb = nil;
qlock(&ic->ackq);
if(ic->unacked)
nb = copyblock(ic->unacked, blocklen(ic->unacked));
qunlock(&ic->ackq);
if(nb == nil)
return;
h = (Ilhdr*)nb->rp;
h->vihl = IP_VER4;
h->iltype = Ildataquery;
hnputl(h->ilack, ic->recvd);
h->ilspec = ilnextqt(ic);
h->ilsum[0] = 0;
h->ilsum[1] = 0;
hnputs(h->ilsum, ptclcsum(nb, IL_IPSIZE, nhgets(h->illen)));
c = ic->conv;
id = nhgetl(h->ilid);
netlog(c->p->f, Logil, "il: rexmit %lud %lud: %d %lud: %I %d/%d\n", id, ic->recvd,
ic->rexmit, ic->timeout,
c->raddr, c->lport, c->rport);
ilbackoff(ic);
ipoput4(c->p->f, nb, nil, c->ttl, c->tos, c);
/* statistics */
ic->rxtot++;
priv = c->p->priv;
priv->rexmit++;
}
/* DEBUG */
void
ilprocess(Conv *s, Ilhdr *h, Block *bp)
{
Ilcb *ic;
ic = (Ilcb*)s->ptcl;
USED(ic);
netlog(s->p->f, Logilmsg, "%11s rcv %lud/%lud snt %lud/%lud pkt(%s id %d ack %ud %ud->%ud) ",
ilstates[ic->state], ic->rstart, ic->recvd, ic->start,
ic->next, iltype[h->iltype], nhgetl(h->ilid),
nhgetl(h->ilack), nhgets(h->ilsrc), nhgets(h->ildst));
_ilprocess(s, h, bp);
netlog(s->p->f, Logilmsg, "%11s rcv %lud snt %lud\n", ilstates[ic->state], ic->recvd, ic->next);
}
void
ilhangup(Conv *s, char *msg)
{
Ilcb *ic;
int callout;
netlog(s->p->f, Logil, "il: hangup! %I %d/%d: %s\n", s->raddr,
s->lport, s->rport, msg?msg:"no reason");
ic = (Ilcb*)s->ptcl;
callout = ic->state == Ilsyncer;
illocalclose(s);
qhangup(s->rq, msg);
qhangup(s->wq, msg);
if(callout)
Fsconnected(s, msg);
}
void
ilpullup(Conv *s)
{
Ilcb *ic;
Ilhdr *oh;
Block *bp;
ulong oid, dlen;
Ilpriv *ipriv;
ic = (Ilcb*)s->ptcl;
if(ic->state != Ilestablished)
return;
qlock(&ic->outo);
while(ic->outoforder) {
bp = ic->outoforder;
oh = (Ilhdr*)bp->rp;
oid = nhgetl(oh->ilid);
if(oid <= ic->recvd) {
ic->outoforder = bp->list;
freeblist(bp);
continue;
}
if(oid != ic->recvd+1){
ipriv = s->p->priv;
ipriv->stats[OutOfOrder]++;
break;
}
ic->recvd = oid;
ic->outoforder = bp->list;
bp->list = nil;
dlen = nhgets(oh->illen)-IL_HDRSIZE;
bp = trimblock(bp, IL_IPSIZE+IL_HDRSIZE, dlen);
/*
* Upper levels don't know about multiple-block
* messages so copy all into one (yick).
*/
qpass(s->rq, packblock(concatblock(bp)));
}
qunlock(&ic->outo);
}
void
iloutoforder(Conv *s, Ilhdr *h, Block *bp)
{
Ilcb *ic;
uchar *lid;
Block *f, **l;
ulong id, newid;
Ilpriv *ipriv;
ipriv = s->p->priv;
ic = (Ilcb*)s->ptcl;
bp->list = nil;
id = nhgetl(h->ilid);
/* Window checks */
if(id <= ic->recvd || id > ic->recvd+ic->window) {
netlog(s->p->f, Logil, "il: message outside window %lud <%lud-%lud>: %I %d/%d\n",
id, ic->recvd, ic->recvd+ic->window, s->raddr, s->lport, s->rport);
freeblist(bp);
return;
}
/* Packet is acceptable so sort onto receive queue for pullup */
qlock(&ic->outo);
if(ic->outoforder == nil)
ic->outoforder = bp;
else {
l = &ic->outoforder;
for(f = *l; f; f = f->list) {
lid = ((Ilhdr*)(f->rp))->ilid;
newid = nhgetl(lid);
if(id <= newid) {
if(id == newid) {
ipriv->stats[DupMsg]++;
ipriv->stats[DupBytes] += blocklen(bp);
qunlock(&ic->outo);
freeblist(bp);
return;
}
bp->list = f;
*l = bp;
qunlock(&ic->outo);
return;
}
l = &f->list;
}
*l = bp;
}
qunlock(&ic->outo);
}
int
ilsendctl(Conv *ipc, Ilhdr *inih, int type, ulong id, ulong ack, int ilspec)
{
Ilhdr *ih;
Ilcb *ic;
Block *bp;
int ttl, tos;
bp = allocb(IL_IPSIZE+IL_HDRSIZE);
bp->wp += IL_IPSIZE+IL_HDRSIZE;
ih = (Ilhdr *)(bp->rp);
ih->vihl = IP_VER4;
/* Ip fields */
ih->proto = IP_ILPROTO;
hnputs(ih->illen, IL_HDRSIZE);
ih->frag[0] = 0;
ih->frag[1] = 0;
if(inih != nil) {
hnputl(ih->dst, nhgetl(inih->src));
hnputl(ih->src, nhgetl(inih->dst));
hnputs(ih->ilsrc, nhgets(inih->ildst));
hnputs(ih->ildst, nhgets(inih->ilsrc));
hnputl(ih->ilid, nhgetl(inih->ilack));
hnputl(ih->ilack, nhgetl(inih->ilid));
ttl = MAXTTL;
tos = DFLTTOS;
}
else {
v6tov4(ih->dst, ipc->raddr);
v6tov4(ih->src, ipc->laddr);
hnputs(ih->ilsrc, ipc->lport);
hnputs(ih->ildst, ipc->rport);
hnputl(ih->ilid, id);
hnputl(ih->ilack, ack);
ic = (Ilcb*)ipc->ptcl;
ic->acksent = ack;
ic->acktime = NOW;
ttl = ipc->ttl;
tos = ipc->tos;
}
ih->iltype = type;
ih->ilspec = ilspec;
ih->ilsum[0] = 0;
ih->ilsum[1] = 0;
if(ilcksum)
hnputs(ih->ilsum, ptclcsum(bp, IL_IPSIZE, IL_HDRSIZE));
if(ipc==nil)
panic("ipc is nil caller is %#p", getcallerpc(&ipc));
if(ipc->p==nil)
panic("ipc->p is nil");
netlog(ipc->p->f, Logilmsg, "ctl(%s id %d ack %d %d->%d)\n",
iltype[ih->iltype], nhgetl(ih->ilid), nhgetl(ih->ilack),
nhgets(ih->ilsrc), nhgets(ih->ildst));
return ipoput4(ipc->p->f, bp, nil, ttl, tos, ipc);
}
void
ilreject(Fs *f, Ilhdr *inih)
{
Ilhdr *ih;
Block *bp;
bp = allocb(IL_IPSIZE+IL_HDRSIZE);
bp->wp += IL_IPSIZE+IL_HDRSIZE;
ih = (Ilhdr *)(bp->rp);
ih->vihl = IP_VER4;
/* Ip fields */
ih->proto = IP_ILPROTO;
hnputs(ih->illen, IL_HDRSIZE);
ih->frag[0] = 0;
ih->frag[1] = 0;
hnputl(ih->dst, nhgetl(inih->src));
hnputl(ih->src, nhgetl(inih->dst));
hnputs(ih->ilsrc, nhgets(inih->ildst));
hnputs(ih->ildst, nhgets(inih->ilsrc));
hnputl(ih->ilid, nhgetl(inih->ilack));
hnputl(ih->ilack, nhgetl(inih->ilid));
ih->iltype = Ilclose;
ih->ilspec = 0;
ih->ilsum[0] = 0;
ih->ilsum[1] = 0;
if(ilcksum)
hnputs(ih->ilsum, ptclcsum(bp, IL_IPSIZE, IL_HDRSIZE));
ipoput4(f, bp, nil, MAXTTL, DFLTTOS, nil);
}
void
ilsettimeout(Ilcb *ic)
{
ulong pt;
pt = (ic->delay>>LogAGain)
+ ic->unackedbytes/(ic->rate>>LogAGain)
+ (ic->mdev>>(LogDGain-1))
+ AckDelay;
if(pt > MaxTimeout)
pt = MaxTimeout;
ic->timeout = NOW + pt;
}
void
ilbackoff(Ilcb *ic)
{
ulong pt;
int i;
pt = (ic->delay>>LogAGain)
+ ic->unackedbytes/(ic->rate>>LogAGain)
+ (ic->mdev>>(LogDGain-1))
+ AckDelay;
for(i = 0; i < ic->rexmit; i++)
pt = pt + (pt>>1);
if(pt > MaxTimeout)
pt = MaxTimeout;
ic->timeout = NOW + pt;
if(ic->fasttimeout)
ic->timeout = NOW+Iltickms;
ic->rexmit++;
}
// complain if two numbers not within an hour of each other
#define Tfuture (1000*60*60)
int
later(ulong t1, ulong t2, char *x)
{
int dt;
dt = t1 - t2;
if(dt > 0) {
if(x != nil && dt > Tfuture)
print("%s: way future %d\n", x, dt);
return 1;
}
if(dt < -Tfuture) {
if(x != nil)
print("%s: way past %d\n", x, -dt);
return 1;
}
return 0;
}
void
ilackproc(void *x)
{
Ilcb *ic;
Conv **s, *p;
Proto *il;
il = x;
while(waserror())
;
loop:
tsleep(&up->sleep, return0, 0, Iltickms);
for(s = il->conv; s && *s; s++) {
p = *s;
ic = (Ilcb*)p->ptcl;
switch(ic->state) {
case Ilclosed:
case Illistening:
break;
case Ilclosing:
if(later(NOW, ic->timeout, "timeout0")) {
if(ic->rexmit > MaxRexmit){
ilhangup(p, nil);
break;
}
ilsendctl(p, nil, Ilclose, ic->next, ic->recvd, 0);
ilbackoff(ic);
}
break;
case Ilsyncee:
case Ilsyncer:
if(later(NOW, ic->timeout, "timeout1")) {
if(ic->rexmit > MaxRexmit){
ilhangup(p, etime);
break;
}
ilsendctl(p, nil, Ilsync, ic->start, ic->recvd, 0);
ilbackoff(ic);
}
break;
case Ilestablished:
if(ic->recvd != ic->acksent)
if(later(NOW, ic->acktime, "acktime"))
ilsendctl(p, nil, Ilack, ic->next, ic->recvd, 0);
if(later(NOW, ic->querytime, "querytime")){
if(later(NOW, ic->lastrecv+DeathTime, "deathtime")){
netlog(il->f, Logil, "il: hangup: deathtime\n");
ilhangup(p, etime);
break;
}
ilsendctl(p, nil, Ilquery, ic->next, ic->recvd, ilnextqt(ic));
ic->querytime = NOW + QueryTime;
}
if(ic->unacked != nil)
if(later(NOW, ic->timeout, "timeout2")) {
if(ic->rexmit > MaxRexmit){
netlog(il->f, Logil, "il: hangup: too many rexmits\n");
ilhangup(p, etime);
break;
}
ilsendctl(p, nil, Ilquery, ic->next, ic->recvd, ilnextqt(ic));
ic->rxquery++;
ilbackoff(ic);
}
break;
}
}
goto loop;
}
void
ilcbinit(Ilcb *ic)
{
ic->start = nrand(0x1000000);
ic->next = ic->start+1;
ic->recvd = 0;
ic->window = Defaultwin;
ic->unackedbytes = 0;
ic->unacked = nil;
ic->outoforder = nil;
ic->rexmit = 0;
ic->rxtot = 0;
ic->rxquery = 0;
ic->qtx = 1;
ic->fasttimeout = 0;
/* timers */
ic->delay = DefRtt<<LogAGain;
ic->mdev = DefRtt<<LogDGain;
ic->rate = DefByteRate<<LogAGain;
ic->querytime = NOW + QueryTime;
ic->lastrecv = NOW; /* or we'll timeout right away */
ilsettimeout(ic);
}
char*
ilstart(Conv *c, int type, int fasttimeout)
{
Ilcb *ic;
Ilpriv *ipriv;
char kpname[KNAMELEN];
ipriv = c->p->priv;
if(ipriv->ackprocstarted == 0){
qlock(&ipriv->apl);
if(ipriv->ackprocstarted == 0){
sprint(kpname, "#I%dilack", c->p->f->dev);
kproc(kpname, ilackproc, c->p);
ipriv->ackprocstarted = 1;
}
qunlock(&ipriv->apl);
}
ic = (Ilcb*)c->ptcl;
ic->conv = c;
if(ic->state != Ilclosed)
return nil;
ilcbinit(ic);
if(fasttimeout){
/* timeout if we can't connect quickly */
ic->fasttimeout = 1;
ic->timeout = NOW+Iltickms;
ic->rexmit = MaxRexmit - 4;
};
switch(type) {
default:
netlog(c->p->f, Logil, "il: start: type %d\n", type);
break;
case IL_LISTEN:
ic->state = Illistening;
iphtadd(&ipriv->ht, c);
break;
case IL_CONNECT:
ic->state = Ilsyncer;
iphtadd(&ipriv->ht, c);
if(ilsendctl(c, nil, Ilsync, ic->start, ic->recvd, 0) < 0)
ilhangup(c, "no route");
break;
}
return nil;
}
void
ilfreeq(Ilcb *ic)
{
Block *bp, *next;
qlock(&ic->ackq);
for(bp = ic->unacked; bp; bp = next) {
next = bp->list;
freeblist(bp);
}
ic->unacked = nil;
qunlock(&ic->ackq);
qlock(&ic->outo);
for(bp = ic->outoforder; bp; bp = next) {
next = bp->list;
freeblist(bp);
}
ic->outoforder = nil;
qunlock(&ic->outo);
}
void
iladvise(Proto *il, Block *bp, Ipifc*, char *msg)
{
uchar source[IPaddrlen], dest[IPaddrlen];
ushort psource, pdest;
Iphash *iph;
Ilhdr *h;
Ilcb *ic;
Conv *s;
if(BLEN(bp) < IL_IPSIZE+IL_HDRSIZE-8){
freeblist(bp);
return;
}
h = (Ilhdr*)(bp->rp);
v4tov6(dest, h->dst);
v4tov6(source, h->src);
pdest = nhgets(h->ildst);
psource = nhgets(h->ilsrc);
/* Look for a connection (source/dest reversed; this is the original packet we sent) */
qlock(il);
iph = iphtlook(&((Ilpriv*)il->priv)->ht, dest, pdest, source, psource);
if(iph == nil || iph->match != IPmatchexact)
goto raise;
s = iphconv(iph);
if(s->ignoreadvice || s->state == Announced)
goto raise;
qlock(s);
qunlock(il);
ic = (Ilcb*)s->ptcl;
if(ic->state == Ilsyncer)
ilhangup(s, msg);
qunlock(s);
freeblist(bp);
return;
raise:
qunlock(il);
freeblist(bp);
}
int
ilnextqt(Ilcb *ic)
{
int x;
qlock(&ic->ackq);
x = ic->qtx;
if(++x > Nqt)
x = 1;
ic->qtx = x;
ic->qt[x] = ic->next-1; /* highest xmitted packet */
ic->qt[0] = ic->qt[x]; /* compatibility with old implementations */
qunlock(&ic->ackq);
return x;
}
/* calculate scale constants that converts fast ticks to ms (more or less) */
static void
inittimescale(void)
{
uvlong hz;
fastticks(&hz);
if(hz > 1000){
scalediv = hz/1000;
scalemul = 1;
} else {
scalediv = 1;
scalemul = 1000/hz;
}
}
void
ilinit(Fs *f)
{
Proto *il;
inittimescale();
il = smalloc(sizeof(Proto));
il->priv = smalloc(sizeof(Ilpriv));
il->name = "il";
il->connect = ilconnect;
il->announce = ilannounce;
il->state = ilstate;
il->create = ilcreate;
il->close = ilclose;
il->rcv = iliput;
il->ctl = nil;
il->advise = iladvise;
il->stats = ilxstats;
il->inuse = ilinuse;
il->gc = nil;
il->ipproto = IP_ILPROTO;
il->nc = scalednconv();
il->ptclsize = sizeof(Ilcb);
Fsproto(f, il);
}