#include "u.h"#include "../port/lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "../port/error.h" typedef struct Link Link;typedef struct Loop Loop; struct Link{ Lock; int ref; long packets; /* total number of packets sent */ long bytes; /* total number of bytes sent */ int indrop; /* enable dropping on iq overflow */ long soverflows; /* packets dropped because iq overflowed */ long droprate; /* drop 1/droprate packets in tq */ long drops; /* packets deliberately dropped */ vlong delay0ns; /* nanosec of delay in the link */ long delaynns; /* nanosec of delay per byte */ Block *tq; /* transmission queue */ Block *tqtail; vlong tout; /* time the last packet in tq is really out */ vlong tin; /* time the head packet in tq enters the remote side */ long limit; /* queue buffering limit */ Queue *oq; /* output queue from other side & packets in the link */ Queue *iq; Timer ci; /* time to move packets from next packet from oq */}; struct Loop{ QLock; int ref; int minmtu; /* smallest block transmittable */ Loop *next; ulong path; Link link[2];}; static struct{ Lock; ulong path;} loopbackalloc; enum{ Qtopdir= 1, /* top level directory */ Qloopdir, /* loopback* directory */ Qportdir, /* directory each end of the loop */ Qctl, Qstatus, Qstats, Qdata, MaxQ, Nloopbacks = 5, Statelen = 23*1024, /* status buffer size */ Tmsize = 8, Delayn = 10000, /* default delays in ns */ Delay0 = 2500000, Loopqlim = 32*1024, /* default size of queues */}; static Dirtab loopportdir[] ={ "ctl", {Qctl}, 0, 0222, "status", {Qstatus}, 0, 0444, "stats", {Qstats}, 0, 0444, "data", {Qdata}, 0, 0666,};static Dirtab loopdirs[MaxQ]; static Loop loopbacks[Nloopbacks]; #define TYPE(x) (((ulong)(x))&0xff)#define ID(x) (((ulong)(x))>>8)#define QID(x,y) ((((ulong)(x))<<8)|((ulong)(y))) static void looper(Loop *lb);static long loopoput(Loop *lb, Link *link, Block *bp);static void ptime(uchar *p, vlong t);static vlong gtime(uchar *p);static void closelink(Link *link, int dofree);static void pushlink(Link *link, vlong now);static void freelb(Loop *lb);static void linkintr(Ureg*, Timer *ci); static voidloopbackinit(void){ int i; for(i = 0; i < Nloopbacks; i++) loopbacks[i].path = i; /* invert directory tables for non-directory entries */ for(i=0; i<nelem(loopportdir); i++) loopdirs[loopportdir[i].qid.path] = loopportdir[i];} static Chan*loopbackattach(char *spec){ Loop *volatile lb; Queue *q; Chan *c; int chan; int dev; dev = 0; if(spec != nil){ dev = atoi(spec); if(dev >= Nloopbacks) error(Ebadspec); } c = devattach('X', spec); lb = &loopbacks[dev]; qlock(lb); if(waserror()){ lb->ref--; qunlock(lb); nexterror(); } lb->ref++; if(lb->ref == 1){ for(chan = 0; chan < 2; chan++){ lb->link[chan].ci.tmode = Tabsolute; lb->link[chan].ci.ta = &lb->link[chan]; lb->link[chan].ci.tf = linkintr; lb->link[chan].limit = Loopqlim; q = qopen(lb->link[chan].limit, 0, 0, 0); lb->link[chan].iq = q; if(q == nil){ freelb(lb); exhausted("memory"); } q = qopen(lb->link[chan].limit, 0, 0, 0); lb->link[chan].oq = q; if(q == nil){ freelb(lb); exhausted("memory"); } lb->link[chan].indrop = 1; lb->link[chan].delaynns = Delayn; lb->link[chan].delay0ns = Delay0; } } poperror(); qunlock(lb); mkqid(&c->qid, QID(0, Qtopdir), 0, QTDIR); c->aux = lb; c->dev = dev; return c;} static intloopbackgen(Chan *c, char*, Dirtab*, int, int i, Dir *dp){ Dirtab *tab; int len, type; Qid qid; type = TYPE(c->qid.path); if(i == DEVDOTDOT){ switch(type){ case Qtopdir: case Qloopdir: snprint(up->genbuf, sizeof(up->genbuf), "#X%ld", c->dev); mkqid(&qid, QID(0, Qtopdir), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); break; case Qportdir: snprint(up->genbuf, sizeof(up->genbuf), "loopback%ld", c->dev); mkqid(&qid, QID(0, Qloopdir), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); break; default: panic("loopbackgen %llux", c->qid.path); } return 1; } switch(type){ case Qtopdir: if(i != 0) return -1; snprint(up->genbuf, sizeof(up->genbuf), "loopback%ld", c->dev); mkqid(&qid, QID(0, Qloopdir), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); return 1; case Qloopdir: if(i >= 2) return -1; snprint(up->genbuf, sizeof(up->genbuf), "%d", i); mkqid(&qid, QID(i, QID(0, Qportdir)), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); return 1; case Qportdir: if(i >= nelem(loopportdir)) return -1; tab = &loopportdir[i]; mkqid(&qid, QID(ID(c->qid.path), tab->qid.path), 0, QTFILE); devdir(c, qid, tab->name, tab->length, eve, tab->perm, dp); return 1; default: /* non directory entries end up here; must be in lowest level */ if(c->qid.type & QTDIR) panic("loopbackgen: unexpected directory"); if(i != 0) return -1; tab = &loopdirs[type]; if(tab == nil) panic("loopbackgen: unknown type: %d", type); len = tab->length; devdir(c, c->qid, tab->name, len, eve, tab->perm, dp); return 1; }} static Walkqid*loopbackwalk(Chan *c, Chan *nc, char **name, int nname){ Walkqid *wq; Loop *lb; wq = devwalk(c, nc, name, nname, nil, 0, loopbackgen); if(wq != nil && wq->clone != nil && wq->clone != c){ lb = c->aux; qlock(lb); lb->ref++; if((c->flag & COPEN) && TYPE(c->qid.path) == Qdata) lb->link[ID(c->qid.path)].ref++; qunlock(lb); } return wq;} static intloopbackstat(Chan *c, uchar *db, int n){ return devstat(c, db, n, nil, 0, loopbackgen);} /* * if the stream doesn't exist, create it */static Chan*loopbackopen(Chan *c, int omode){ Loop *lb; if(c->qid.type & QTDIR){ if(omode != OREAD) error(Ebadarg); c->mode = omode; c->flag |= COPEN; c->offset = 0; return c; } lb = c->aux; qlock(lb); if(TYPE(c->qid.path) == Qdata){ if(lb->link[ID(c->qid.path)].ref){ qunlock(lb); error(Einuse); } lb->link[ID(c->qid.path)].ref++; } qunlock(lb); c->mode = openmode(omode); c->flag |= COPEN; c->offset = 0; c->iounit = qiomaxatomic; return c;} static voidloopbackclose(Chan *c){ Loop *lb; int ref, chan; lb = c->aux; qlock(lb); /* * closing either side hangs up the stream */ if((c->flag & COPEN) && TYPE(c->qid.path) == Qdata){ chan = ID(c->qid.path); if(--lb->link[chan].ref == 0){ qhangup(lb->link[chan ^ 1].oq, nil); looper(lb); } } /* * if both sides are closed, they are reusable */ if(lb->link[0].ref == 0 && lb->link[1].ref == 0){ for(chan = 0; chan < 2; chan++){ closelink(&lb->link[chan], 0); qreopen(lb->link[chan].iq); qreopen(lb->link[chan].oq); qsetlimit(lb->link[chan].oq, lb->link[chan].limit); qsetlimit(lb->link[chan].iq, lb->link[chan].limit); } } ref = --lb->ref; if(ref == 0) freelb(lb); qunlock(lb);} static voidfreelb(Loop *lb){ int chan; for(chan = 0; chan < 2; chan++) closelink(&lb->link[chan], 1);} /* * called with the Loop qlocked, * so only pushlink can mess with the queues */static voidcloselink(Link *link, int dofree){ Queue *iq, *oq; Block *bp; ilock(link); iq = link->iq; oq = link->oq; bp = link->tq; link->tq = nil; link->tqtail = nil; link->tout = 0; link->tin = 0; timerdel(&link->ci); iunlock(link); if(iq != nil){ qclose(iq); if(dofree){ ilock(link); free(iq); link->iq = nil; iunlock(link); } } if(oq != nil){ qclose(oq); if(dofree){ ilock(link); free(oq); link->oq = nil; iunlock(link); } } freeblist(bp);} static longloopbackread(Chan *c, void *va, long n, vlong offset){ Loop *lb; Link *link; char *buf; long rv; lb = c->aux; switch(TYPE(c->qid.path)){ default: error(Eperm); return -1; /* not reached */ case Qtopdir: case Qloopdir: case Qportdir: return devdirread(c, va, n, nil, 0, loopbackgen); case Qdata: return qread(lb->link[ID(c->qid.path)].iq, va, n); case Qstatus: link = &lb->link[ID(c->qid.path)]; buf = smalloc(Statelen); rv = snprint(buf, Statelen, "delay %lld %ld\n", link->delay0ns, link->delaynns); rv += snprint(buf+rv, Statelen-rv, "limit %ld\n", link->limit); rv += snprint(buf+rv, Statelen-rv, "indrop %d\n", link->indrop); snprint(buf+rv, Statelen-rv, "droprate %ld\n", link->droprate); rv = readstr(offset, va, n, buf); free(buf); break; case Qstats: link = &lb->link[ID(c->qid.path)]; buf = smalloc(Statelen); rv = snprint(buf, Statelen, "packets: %ld\n", link->packets); rv += snprint(buf+rv, Statelen-rv, "bytes: %ld\n", link->bytes); rv += snprint(buf+rv, Statelen-rv, "dropped: %ld\n", link->drops); snprint(buf+rv, Statelen-rv, "soft overflows: %ld\n", link->soverflows); rv = readstr(offset, va, n, buf); free(buf); break; } return rv;} static Block*loopbackbread(Chan *c, long n, ulong offset){ Loop *lb; lb = c->aux; if(TYPE(c->qid.path) == Qdata) return qbread(lb->link[ID(c->qid.path)].iq, n); return devbread(c, n, offset);} static longloopbackbwrite(Chan *c, Block *bp, ulong off){ Loop *lb; lb = c->aux; if(TYPE(c->qid.path) == Qdata) return loopoput(lb, &lb->link[ID(c->qid.path) ^ 1], bp); return devbwrite(c, bp, off);} static longloopbackwrite(Chan *c, void *va, long n, vlong off){ Loop *lb; Link *link; Cmdbuf *volatile cb; Block *volatile bp; vlong d0ns; long dnns; switch(TYPE(c->qid.path)){ case Qdata: bp = allocb(n); if(waserror()){ freeb(bp); nexterror(); } memmove(bp->wp, va, n); poperror(); bp->wp += n; return loopbackbwrite(c, bp, off); case Qctl: lb = c->aux; link = &lb->link[ID(c->qid.path)]; cb = parsecmd(va, n); if(waserror()){ free(cb); nexterror(); } if(cb->nf < 1) error("short control request"); if(strcmp(cb->f[0], "delay") == 0){ if(cb->nf != 3) error("usage: delay latency bytedelay"); d0ns = strtoll(cb->f[1], nil, 10); dnns = strtol(cb->f[2], nil, 10); /* * it takes about 20000 cycles on a pentium ii * to run pushlink; perhaps this should be accounted. */ ilock(link); link->delay0ns = d0ns;Lines 1–500 of 743. 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#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" typedef struct Link Link; typedef struct Loop Loop; struct Link { Lock; int ref; long packets; /* total number of packets sent */ long bytes; /* total number of bytes sent */ int indrop; /* enable dropping on iq overflow */ long soverflows; /* packets dropped because iq overflowed */ long droprate; /* drop 1/droprate packets in tq */ long drops; /* packets deliberately dropped */ vlong delay0ns; /* nanosec of delay in the link */ long delaynns; /* nanosec of delay per byte */ Block *tq; /* transmission queue */ Block *tqtail; vlong tout; /* time the last packet in tq is really out */ vlong tin; /* time the head packet in tq enters the remote side */ long limit; /* queue buffering limit */ Queue *oq; /* output queue from other side & packets in the link */ Queue *iq; Timer ci; /* time to move packets from next packet from oq */ }; struct Loop { QLock; int ref; int minmtu; /* smallest block transmittable */ Loop *next; ulong path; Link link[2]; }; static struct { Lock; ulong path; } loopbackalloc; enum { Qtopdir= 1, /* top level directory */ Qloopdir, /* loopback* directory */ Qportdir, /* directory each end of the loop */ Qctl, Qstatus, Qstats, Qdata, MaxQ, Nloopbacks = 5, Statelen = 23*1024, /* status buffer size */ Tmsize = 8, Delayn = 10000, /* default delays in ns */ Delay0 = 2500000, Loopqlim = 32*1024, /* default size of queues */ }; static Dirtab loopportdir[] = { "ctl", {Qctl}, 0, 0222, "status", {Qstatus}, 0, 0444, "stats", {Qstats}, 0, 0444, "data", {Qdata}, 0, 0666, }; static Dirtab loopdirs[MaxQ]; static Loop loopbacks[Nloopbacks]; #define TYPE(x) (((ulong)(x))&0xff) #define ID(x) (((ulong)(x))>>8) #define QID(x,y) ((((ulong)(x))<<8)|((ulong)(y))) static void looper(Loop *lb); static long loopoput(Loop *lb, Link *link, Block *bp); static void ptime(uchar *p, vlong t); static vlong gtime(uchar *p); static void closelink(Link *link, int dofree); static void pushlink(Link *link, vlong now); static void freelb(Loop *lb); static void linkintr(Ureg*, Timer *ci); static void loopbackinit(void) { int i; for(i = 0; i < Nloopbacks; i++) loopbacks[i].path = i; /* invert directory tables for non-directory entries */ for(i=0; i<nelem(loopportdir); i++) loopdirs[loopportdir[i].qid.path] = loopportdir[i]; } static Chan* loopbackattach(char *spec) { Loop *volatile lb; Queue *q; Chan *c; int chan; int dev; dev = 0; if(spec != nil){ dev = atoi(spec); if(dev >= Nloopbacks) error(Ebadspec); } c = devattach('X', spec); lb = &loopbacks[dev]; qlock(lb); if(waserror()){ lb->ref--; qunlock(lb); nexterror(); } lb->ref++; if(lb->ref == 1){ for(chan = 0; chan < 2; chan++){ lb->link[chan].ci.tmode = Tabsolute; lb->link[chan].ci.ta = &lb->link[chan]; lb->link[chan].ci.tf = linkintr; lb->link[chan].limit = Loopqlim; q = qopen(lb->link[chan].limit, 0, 0, 0); lb->link[chan].iq = q; if(q == nil){ freelb(lb); exhausted("memory"); } q = qopen(lb->link[chan].limit, 0, 0, 0); lb->link[chan].oq = q; if(q == nil){ freelb(lb); exhausted("memory"); } lb->link[chan].indrop = 1; lb->link[chan].delaynns = Delayn; lb->link[chan].delay0ns = Delay0; } } poperror(); qunlock(lb); mkqid(&c->qid, QID(0, Qtopdir), 0, QTDIR); c->aux = lb; c->dev = dev; return c; } static int loopbackgen(Chan *c, char*, Dirtab*, int, int i, Dir *dp) { Dirtab *tab; int len, type; Qid qid; type = TYPE(c->qid.path); if(i == DEVDOTDOT){ switch(type){ case Qtopdir: case Qloopdir: snprint(up->genbuf, sizeof(up->genbuf), "#X%ld", c->dev); mkqid(&qid, QID(0, Qtopdir), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); break; case Qportdir: snprint(up->genbuf, sizeof(up->genbuf), "loopback%ld", c->dev); mkqid(&qid, QID(0, Qloopdir), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); break; default: panic("loopbackgen %llux", c->qid.path); } return 1; } switch(type){ case Qtopdir: if(i != 0) return -1; snprint(up->genbuf, sizeof(up->genbuf), "loopback%ld", c->dev); mkqid(&qid, QID(0, Qloopdir), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); return 1; case Qloopdir: if(i >= 2) return -1; snprint(up->genbuf, sizeof(up->genbuf), "%d", i); mkqid(&qid, QID(i, QID(0, Qportdir)), 0, QTDIR); devdir(c, qid, up->genbuf, 0, eve, 0555, dp); return 1; case Qportdir: if(i >= nelem(loopportdir)) return -1; tab = &loopportdir[i]; mkqid(&qid, QID(ID(c->qid.path), tab->qid.path), 0, QTFILE); devdir(c, qid, tab->name, tab->length, eve, tab->perm, dp); return 1; default: /* non directory entries end up here; must be in lowest level */ if(c->qid.type & QTDIR) panic("loopbackgen: unexpected directory"); if(i != 0) return -1; tab = &loopdirs[type]; if(tab == nil) panic("loopbackgen: unknown type: %d", type); len = tab->length; devdir(c, c->qid, tab->name, len, eve, tab->perm, dp); return 1; } } static Walkqid* loopbackwalk(Chan *c, Chan *nc, char **name, int nname) { Walkqid *wq; Loop *lb; wq = devwalk(c, nc, name, nname, nil, 0, loopbackgen); if(wq != nil && wq->clone != nil && wq->clone != c){ lb = c->aux; qlock(lb); lb->ref++; if((c->flag & COPEN) && TYPE(c->qid.path) == Qdata) lb->link[ID(c->qid.path)].ref++; qunlock(lb); } return wq; } static int loopbackstat(Chan *c, uchar *db, int n) { return devstat(c, db, n, nil, 0, loopbackgen); } /* * if the stream doesn't exist, create it */ static Chan* loopbackopen(Chan *c, int omode) { Loop *lb; if(c->qid.type & QTDIR){ if(omode != OREAD) error(Ebadarg); c->mode = omode; c->flag |= COPEN; c->offset = 0; return c; } lb = c->aux; qlock(lb); if(TYPE(c->qid.path) == Qdata){ if(lb->link[ID(c->qid.path)].ref){ qunlock(lb); error(Einuse); } lb->link[ID(c->qid.path)].ref++; } qunlock(lb); c->mode = openmode(omode); c->flag |= COPEN; c->offset = 0; c->iounit = qiomaxatomic; return c; } static void loopbackclose(Chan *c) { Loop *lb; int ref, chan; lb = c->aux; qlock(lb); /* * closing either side hangs up the stream */ if((c->flag & COPEN) && TYPE(c->qid.path) == Qdata){ chan = ID(c->qid.path); if(--lb->link[chan].ref == 0){ qhangup(lb->link[chan ^ 1].oq, nil); looper(lb); } } /* * if both sides are closed, they are reusable */ if(lb->link[0].ref == 0 && lb->link[1].ref == 0){ for(chan = 0; chan < 2; chan++){ closelink(&lb->link[chan], 0); qreopen(lb->link[chan].iq); qreopen(lb->link[chan].oq); qsetlimit(lb->link[chan].oq, lb->link[chan].limit); qsetlimit(lb->link[chan].iq, lb->link[chan].limit); } } ref = --lb->ref; if(ref == 0) freelb(lb); qunlock(lb); } static void freelb(Loop *lb) { int chan; for(chan = 0; chan < 2; chan++) closelink(&lb->link[chan], 1); } /* * called with the Loop qlocked, * so only pushlink can mess with the queues */ static void closelink(Link *link, int dofree) { Queue *iq, *oq; Block *bp; ilock(link); iq = link->iq; oq = link->oq; bp = link->tq; link->tq = nil; link->tqtail = nil; link->tout = 0; link->tin = 0; timerdel(&link->ci); iunlock(link); if(iq != nil){ qclose(iq); if(dofree){ ilock(link); free(iq); link->iq = nil; iunlock(link); } } if(oq != nil){ qclose(oq); if(dofree){ ilock(link); free(oq); link->oq = nil; iunlock(link); } } freeblist(bp); } static long loopbackread(Chan *c, void *va, long n, vlong offset) { Loop *lb; Link *link; char *buf; long rv; lb = c->aux; switch(TYPE(c->qid.path)){ default: error(Eperm); return -1; /* not reached */ case Qtopdir: case Qloopdir: case Qportdir: return devdirread(c, va, n, nil, 0, loopbackgen); case Qdata: return qread(lb->link[ID(c->qid.path)].iq, va, n); case Qstatus: link = &lb->link[ID(c->qid.path)]; buf = smalloc(Statelen); rv = snprint(buf, Statelen, "delay %lld %ld\n", link->delay0ns, link->delaynns); rv += snprint(buf+rv, Statelen-rv, "limit %ld\n", link->limit); rv += snprint(buf+rv, Statelen-rv, "indrop %d\n", link->indrop); snprint(buf+rv, Statelen-rv, "droprate %ld\n", link->droprate); rv = readstr(offset, va, n, buf); free(buf); break; case Qstats: link = &lb->link[ID(c->qid.path)]; buf = smalloc(Statelen); rv = snprint(buf, Statelen, "packets: %ld\n", link->packets); rv += snprint(buf+rv, Statelen-rv, "bytes: %ld\n", link->bytes); rv += snprint(buf+rv, Statelen-rv, "dropped: %ld\n", link->drops); snprint(buf+rv, Statelen-rv, "soft overflows: %ld\n", link->soverflows); rv = readstr(offset, va, n, buf); free(buf); break; } return rv; } static Block* loopbackbread(Chan *c, long n, ulong offset) { Loop *lb; lb = c->aux; if(TYPE(c->qid.path) == Qdata) return qbread(lb->link[ID(c->qid.path)].iq, n); return devbread(c, n, offset); } static long loopbackbwrite(Chan *c, Block *bp, ulong off) { Loop *lb; lb = c->aux; if(TYPE(c->qid.path) == Qdata) return loopoput(lb, &lb->link[ID(c->qid.path) ^ 1], bp); return devbwrite(c, bp, off); } static long loopbackwrite(Chan *c, void *va, long n, vlong off) { Loop *lb; Link *link; Cmdbuf *volatile cb; Block *volatile bp; vlong d0ns; long dnns; switch(TYPE(c->qid.path)){ case Qdata: bp = allocb(n); if(waserror()){ freeb(bp); nexterror(); } memmove(bp->wp, va, n); poperror(); bp->wp += n; return loopbackbwrite(c, bp, off); case Qctl: lb = c->aux; link = &lb->link[ID(c->qid.path)]; cb = parsecmd(va, n); if(waserror()){ free(cb); nexterror(); } if(cb->nf < 1) error("short control request"); if(strcmp(cb->f[0], "delay") == 0){ if(cb->nf != 3) error("usage: delay latency bytedelay"); d0ns = strtoll(cb->f[1], nil, 10); dnns = strtol(cb->f[2], nil, 10); /* * it takes about 20000 cycles on a pentium ii * to run pushlink; perhaps this should be accounted. */ ilock(link); link->delay0ns = d0ns;