ref: c8e25d2a18c0395431abc5818a1d2f0561b0181f
dir: /sys/src/cmd/vnc/devcons.c/
#include <u.h> #include <libc.h> #include "compat.h" #include "kbd.h" #include "error.h" Snarf snarf = { .vers = 1 }; enum{ Qdir, Qcons, Qconsctl, Qsnarf, }; static Dirtab consdir[]={ ".", {Qdir, 0, QTDIR}, 0, DMDIR|0555, "cons", {Qcons}, 0, 0660, "consctl", {Qconsctl}, 0, 0220, "snarf", {Qsnarf}, 0, 0600, }; static Chan* consattach(char *spec) { return devattach('c', spec); } static Walkqid* conswalk(Chan *c, Chan *nc, char **name, int nname) { return devwalk(c, nc, name,nname, consdir, nelem(consdir), devgen); } static int consstat(Chan *c, uchar *dp, int n) { return devstat(c, dp, n, consdir, nelem(consdir), devgen); } static Chan* consopen(Chan *c, int omode) { c->aux = nil; c = devopen(c, omode, consdir, nelem(consdir), devgen); switch((ulong)c->qid.path){ case Qconsctl: break; case Qsnarf: if((c->mode&3) == OWRITE || (c->mode&3) == ORDWR) c->aux = smalloc(sizeof(Snarf)); break; } return c; } void setsnarf(char *buf, int n, int *vers) { int i; qlock(&snarf); snarf.vers++; if(vers) *vers = snarf.vers; for(i = 0; i < nelem(consdir); i++){ if(consdir[i].qid.type == Qsnarf){ consdir[i].qid.vers = snarf.vers; break; } } free(snarf.buf); snarf.n = n; snarf.buf = buf; qunlock(&snarf); } static void consclose(Chan *c) { Snarf *t; switch((ulong)c->qid.path){ /* last close of control file turns off raw */ case Qconsctl: break; /* odd behavior but really ok: replace snarf buffer when /dev/snarf is closed */ case Qsnarf: t = c->aux; if(t == nil) break; setsnarf(t->buf, t->n, 0); t->buf = nil; /* setsnarf took it */ free(t); c->aux = nil; break; } } static long consread(Chan *c, void *buf, long n, vlong off) { if(n <= 0) return n; switch((ulong)c->qid.path){ case Qsnarf: qlock(&snarf); if(off < snarf.n){ if(off + n > snarf.n) n = snarf.n - off; memmove(buf, snarf.buf+off, n); }else n = 0; qunlock(&snarf); return n; case Qdir: return devdirread(c, buf, n, consdir, nelem(consdir), devgen); case Qcons: error(Egreg); return -1; default: print("consread 0x%llux\n", c->qid.path); error(Egreg); } return -1; /* never reached */ } static long conswrite(Chan *c, void *va, long n, vlong) { Snarf *t; char *a; switch((ulong)c->qid.path){ case Qcons: screenputs(va, n); break; case Qconsctl: error(Egreg); break; case Qsnarf: t = c->aux; /* always append only */ if(t->n > MAXSNARF) /* avoid thrashing when people cut huge text */ error("snarf buffer too big"); a = realloc(t->buf, t->n + n + 1); if(a == nil) error("snarf buffer too big"); t->buf = a; memmove(t->buf+t->n, va, n); t->n += n; t->buf[t->n] = '\0'; break; default: print("conswrite: 0x%llux\n", c->qid.path); error(Egreg); } return n; } Dev consdevtab = { 'c', "cons", devreset, devinit, consattach, conswalk, consstat, consopen, devcreate, consclose, consread, devbread, conswrite, devbwrite, devremove, devwstat, };