1990/0227/port/sysfile.c (diff list | history)

port/sysfile.c on 1990/0227
1990/0227		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "errno.h" #include "fcall.h" /* * The sys*() routines needn't poperror() as they return directly to syscall(). */ int newfd(void) { int i; for(i=0; i<NFD; i++) if(u->fd[i] == 0){ if(i > u->maxfd) u->maxfd = i; return i; } error(0, Enofd); } Chan* fdtochan(int fd, int mode) { Chan *c; if(fd<0 || NFD<=fd || (c=u->fd[fd])==0) error(0, Ebadfd); if(mode<0 || c->mode == 2) return c; if((mode&16) && c->mode==0) err: error(0, Ebadusefd); if((mode&~16) != c->mode) goto err; return c; } int openmode(ulong o) { if(o >= (OTRUNC|OEXEC)) Err: error(0, Ebadarg); o &= ~OTRUNC; if(o > OEXEC) goto Err; if(o == OEXEC) return OREAD; return o; } long sysdup(ulong *arg) { int fd; Chan *c, *oc; /* * Close after dup'ing, so date > #d/1 works */ c = fdtochan(arg[0], -1); fd = arg[1]; if(fd != -1) oc = u->fd[fd]; else{ oc = 0; fd = newfd(); } u->fd[fd] = c; incref(c); if(oc) close(oc); return fd; } long sysopen(ulong *arg) { int fd; Chan *c; openmode(arg[1]); /* error check only */ fd = newfd(); validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aopen, arg[1], 0); u->fd[fd] = c; return fd; } void fdclose(int fd) { int i; u->fd[fd] = 0; if(fd == u->maxfd) for(i=fd; --i>=0 && u->fd[i]==0; ) u->maxfd = i; } long sysclose(ulong *arg) { Chan *c; c = fdtochan(arg[0], -1); close(c); fdclose(arg[0]); return 0; } long unionread(Chan *c, void *va, long n) { Mount *mnt; Chan *mc, *nc; Pgrp *pg = u->p->pgrp; long nr; mnt = c->mnt; lock(pg); if(c->mountid != mnt->mountid){ print("unionread: changed underfoot?\n"); unlock(pg); return 0; } Again: mc = mnt->c; incref(mc); unlock(pg); if(waserror()){ close(mc); nexterror(); } nc = clone(mc, 0); close(mc); poperror(); if(waserror()){ close(nc); nexterror(); } nc = (*devtab[nc->type].open)(nc, OREAD); nc->offset = c->offset; nr = (*devtab[nc->type].read)(nc, va, n); close(nc); poperror(); if(nr > 0) return nr; /* * Advance to next element */ lock(pg); mnt = c->mnt; if(c->mountid != mnt->mountid){ print("unionread: changed underfoot?\n"); unlock(pg); return 0; } if(mnt->term){ unlock(pg); return 0; } mnt = mnt->next; c->mnt = mnt; c->mountid = mnt->mountid; c->offset = 0; goto Again; } long sysread(ulong *arg) { Chan *c; long n; c = fdtochan(arg[0], 0); validaddr(arg[1], arg[2], 0); qlock(c); if(waserror()){ qunlock(c); nexterror(); } n = arg[2]; if(c->qid&CHDIR){ n -= n%DIRLEN; if(c->offset%DIRLEN || n==0) error(0, Ebaddirread); } if((c->qid&CHDIR) && c->flag&CMOUNT) n = unionread(c, (void*)arg[1], n); else n = (*devtab[c->type].read)(c, (void*)arg[1], n); c->offset += n; qunlock(c); return n; } long syswrite(ulong *arg) { Chan *c; long n; c = fdtochan(arg[0], 1); validaddr(arg[1], arg[2], 0); qlock(c); if(waserror()){ qunlock(c); nexterror(); } if(c->qid & CHDIR) error(0, Eisdir); n = (*devtab[c->type].write)(c, (void*)arg[1], arg[2]); c->offset += n; qunlock(c); return n; } long sysseek(ulong *arg) { Chan *c; char buf[DIRLEN]; Dir dir; long off; c = fdtochan(arg[0], -1); if(c->qid & CHDIR) error(0, Eisdir); qlock(c); if(waserror()){ qunlock(c); nexterror(); } switch(arg[2]){ case 0: c->offset = arg[1]; break; case 1: c->offset += (long)arg[1]; break; case 2: (*devtab[c->type].stat)(c, buf); convM2D(buf, &dir); c->offset = dir.length + (long)arg[1]; break; } off = c->offset; qunlock(c); poperror(); return off; } long sysfstat(ulong *arg) { Chan *c; long n; validaddr(arg[1], DIRLEN, 1); evenaddr(arg[1]); c = fdtochan(arg[0], -1); (*devtab[c->type].stat)(c, (char*)arg[1]); return 0; } long sysstat(ulong *arg) { Chan *c; long n; validaddr(arg[1], DIRLEN, 1); evenaddr(arg[1]); validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); if(waserror()){ close(c); nexterror(); } (*devtab[c->type].stat)(c, (char*)arg[1]); poperror(); close(c); return 0; } long sysaccess(ulong *arg) { Chan *c; long mode; validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); mode = c->mode; close(c); /* BUG: check modes */ return 0; } long syschdir(ulong *arg) { Chan *c; validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Atodir, 0, 0); close(u->dot); u->dot = c; return 0; } long bindmount(ulong *arg, int ismount) { Chan *c0, *c1; ulong flag; long ret; struct{ Chan *chan; char *spec; }bogus; flag = arg[2]; if(flag>MMASK || (flag&MORDER)==(MBEFORE|MAFTER)) error(0, Ebadarg); if(ismount){ bogus.chan = fdtochan(arg[0], 2); /*BUG: check validaddr for ALL of arg[3]!! */ validaddr(arg[3], 1, 0); bogus.spec = (char*)arg[3]; ret = devno('M', 0); c0 = (*devtab[ret].attach)((char*)&bogus); }else{ validaddr(arg[0], 1, 0); c0 = namec((char*)arg[0], Aaccess, 0, 0); } if(waserror()){ close(c0); nexterror(); } validaddr(arg[1], 1, 0); c1 = namec((char*)arg[1], Amount, 0, 0); if(waserror()){ close(c1); nexterror(); } if((c0->qid^c1->qid) & CHDIR) error(0, Ebadmount); if(flag && !(c0->qid&CHDIR)) error(0, Ebadmount); ret = mount(c0, c1, flag); close(c0); close(c1); if(ismount){ close(bogus.chan); fdclose(arg[0]); } return ret; } long sysbind(ulong *arg) { return bindmount(arg, 0); } long sysmount(ulong *arg) { return bindmount(arg, 1); } long syspipe(ulong *arg) { int fd[2]; Chan *c[2]; Dev *d; validaddr(arg[0], 2*BY2WD, 1); evenaddr(arg[0]); d = &devtab[devno('|', 0)]; c[0] = (*d->attach)(0); c[1] = 0; fd[0] = -1; fd[1] = -1; if(waserror()){ close(c[0]); if(c[1]) close(c[1]); if(fd[0] >= 0) u->fd[fd[0]]=0; if(fd[1] >= 0) u->fd[fd[1]]=0; nexterror(); } c[1] = (*d->clone)(c[0], 0); c[0] = (*d->open)(c[0], ORDWR); c[1] = (*d->open)(c[1], ORDWR); c[0]->mode = 2; c[1]->mode = 2; c[0]->flag |= COPEN; c[1]->flag |= COPEN; fd[0] = newfd(); u->fd[fd[0]] = c[0]; fd[1] = newfd(); u->fd[fd[1]] = c[1]; ((long*)arg[0])[0] = fd[0]; ((long*)arg[0])[1] = fd[1]; poperror(); return 0; } long syscreate(ulong *arg) { int fd; Chan *c; openmode(arg[1]); /* error check only */ fd = newfd(); validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Acreate, arg[1], arg[2]); u->fd[fd] = c; return fd; } long sysuserstr(ulong *arg) { Error err; char buf[NAMELEN]; validaddr(arg[0], sizeof(Error), 0); validaddr(arg[1], NAMELEN, 1); err = *(Error*)arg[0]; err.type = devno(err.type, 1); if(err.type == -1) strcpy((char*)arg[1], "*gok*"); else{ (*devtab[err.type].userstr)(&err, buf); memcpy((char*)arg[1], buf, sizeof buf); } return 0; } long sysremove(ulong *arg) { Chan *c; validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); if(waserror()){ close(c); nexterror(); } (*devtab[c->type].remove)(c); /* * Remove clunks the fid, but we need to recover the Chan * so fake it up. rootclose() is known to be a nop. */ c->type = 0; close(c); return 0; } long syswstat(ulong *arg) { Chan *c; long n; validaddr(arg[1], DIRLEN, 0); evenaddr(arg[1]); validaddr(arg[0], 1, 0); c = namec((char*)arg[0], Aaccess, 0, 0); if(waserror()){ close(c); nexterror(); } (*devtab[c->type].wstat)(c, (char*)arg[1]); poperror(); close(c); return 0; } long sysfwstat(ulong *arg) { Chan *c; long n; validaddr(arg[1], DIRLEN, 0); evenaddr(arg[1]); c = fdtochan(arg[0], -1); (*devtab[c->type].wstat)(c, (char*)arg[1]); return 0; }