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

port/dev.c on 1990/0227
1990/0227		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "errno.h" #define DEVTAB #include "devtab.h" #include "fcall.h" int devno(int c, int user) { char *s; s = strchr(devchar, c); if(s==0 || c==0){ if(user) return -1; panic("devno %c 0x%ux", c, c); } return s - devchar; } void devdir(Chan *c, long qid, char *n, long length, long perm, Dir *db) { strcpy(db->name, n); db->qid = qid; db->type = devchar[c->type]; db->dev = c->dev; if(qid & CHDIR) db->mode = CHDIR|perm; else db->mode = perm; db->atime = seconds(); db->mtime = db->atime; db->hlength = 0; db->length = length; db->uid = 0; db->gid = 0; } int devgen(Chan *c, Dirtab *tab, int ntab, int i, Dir *dp) { if(tab==0 || i>=ntab) return -1; tab += i; devdir(c, tab->qid, tab->name, tab->length, tab->perm, dp); return 1; } Chan * devattach(int tc, char *spec) { Chan *c; c = newchan(); c->qid = CHDIR; c->type = devno(tc, 0); return c; } Chan * devclone(Chan *c, Chan *nc) { if(nc == 0) nc = newchan(); nc->type = c->type; nc->mode = c->mode; nc->qid = c->qid; nc->offset = c->offset; nc->dev = c->dev; nc->flag = c->flag; nc->mnt = c->mnt; return nc; } int devwalk(Chan *c, char *name, Dirtab *tab, int ntab, Devgen *gen) { long i; Dir dir; isdir(c); if(name[0]=='.' && name[1]==0) return 1; for(i=0;; i++) switch((*gen)(c, tab, ntab, i, &dir)){ case -1: u->error.type = 0; u->error.dev = 0; u->error.code = Enonexist; return 0; case 0: continue; case 1: if(strcmp(name, dir.name) == 0){ c->qid = dir.qid; return 1; } continue; } } void devstat(Chan *c, char *db, Dirtab *tab, int ntab, Devgen *gen) { int i; Dir dir; for(i=0;; i++) switch((*gen)(c, tab, ntab, i, &dir)){ case -1: /* * devices with interesting directories usually don't get * here, which is good because we've lost the name by now. */ if(c->qid & CHDIR){ devdir(c, c->qid, ".", 0L, CHDIR|0700, &dir); convD2M(&dir, db); return; } panic("devstat"); case 0: break; case 1: if(c->qid == dir.qid){ convD2M(&dir, db); return; } break; } } long devdirread(Chan *c, char *d, long n, Dirtab *tab, int ntab, Devgen *gen) { long k, l, m; Dir dir; k = c->offset/DIRLEN; l = (c->offset+n)/DIRLEN; n = 0; for(m=k; m<l; k++) switch((*gen)(c, tab, ntab, k, &dir)){ case -1: return n; case 0: c->offset += DIRLEN; break; case 1: convD2M(&dir, d); n += DIRLEN; d += DIRLEN; m++; break; } return n; } Chan * devopen(Chan *c, int omode, Dirtab *tab, int ntab, Devgen *gen) { int i; Dir dir; static int access[] = { 0400, 0200, 0600, 0100 }; for(i=0;; i++) switch((*gen)(c, tab, ntab, i, &dir)){ case -1: /* Deal with union directories? */ goto Return; case 0: break; case 1: if(c->qid == dir.qid){ if((access[omode&3] & dir.mode) == access[omode&3]) goto Return; error(0, Eperm); } break; } Return: c->offset = 0; if((c->qid&CHDIR) && omode!=OREAD) error(0, Eperm); c->mode = openmode(omode); c->flag |= COPEN; return c; }