tapefs from plan9

src/cmd/tapefs/util.c

@@ -0,0 +1,153 @@
+#include <u.h>
+#include <libc.h>
+#include <auth.h>
+#include <fcall.h>
+#include <bio.h>
+#include "tapefs.h"
+
+Idmap *
+getpass(char *file)
+{
+	Biobuf *bp;
+	char *cp;
+	Idmap *up;
+	int nid, maxid;
+	char *line[4];
+
+	if ((bp = Bopen(file, OREAD)) == 0)
+		error("Can't open passwd/group");
+	up = emalloc(1*sizeof(Idmap));
+	maxid = 1;
+	nid = 0;
+	while ((cp = Brdline(bp, '\n'))) {
+		int nf;
+		cp[Blinelen(bp)-1] = 0;
+		nf = getfields(cp, line, 3, 0, ":\n");
+		if (nf<3) {
+			fprint(2, "bad format in %s\n", file);
+			break;
+		}
+		if (nid>=maxid) {
+			maxid *= 2;
+			up = (Idmap *)erealloc(up, maxid*sizeof(Idmap));
+		}
+		up[nid].id = atoi(line[2]);
+		up[nid].name = strdup(line[0]);
+		nid++;
+	}		
+	Bterm(bp);
+	up[nid].name = 0;
+	return up;
+}
+
+char *
+mapid(Idmap *up, int id)
+{
+	char buf[16];
+
+	if (up)
+		while (up->name){
+			if (up->id==id)
+				return strdup(up->name);
+			up++;
+		}
+	sprint(buf, "%d", id);
+	return strdup(buf);
+}
+
+Ram *
+poppath(Fileinf fi, int new)
+{
+	char *suffix;
+	Ram *dir, *ent;
+	Fileinf f;
+
+	if (*fi.name=='\0')
+		return 0;
+	if (suffix=strrchr(fi.name, '/')){
+		*suffix = 0;
+		suffix++;
+		if (*suffix=='\0'){
+			fi.mode |= DMDIR;
+			return poppath(fi, 1);
+		}
+		f = fi;
+		f.size = 0;
+		f.addr = 0;
+		f.mode = 0555|DMDIR;
+		dir = poppath(f, 0);
+		if (dir==0)
+			dir = ram;
+	} else {
+		suffix = fi.name;
+		dir = ram;
+		if (strcmp(suffix, ".")==0)
+			return dir;
+	}
+	ent = lookup(dir, suffix);
+	fi.mode |= 0400;			/* at least user read */
+	if (ent){
+		if (((fi.mode&DMDIR)!=0) != ((ent->qid.type&QTDIR)!=0)){
+			fprint(2, "%s/%s directory botch\n", fi.name, suffix);
+			exits("");
+		}
+		if (new)  {
+			ent->ndata = fi.size;
+			ent->addr = fi.addr;
+			ent->data = fi.data;
+			ent->perm = fi.mode;
+			ent->mtime = fi.mdate;
+			ent->user = mapid(uidmap, fi.uid);
+			ent->group = mapid(gidmap, fi.gid);
+		}
+	} else {
+		fi.name = suffix;
+		ent = popfile(dir, fi);
+	}
+	return ent;
+}
+
+Ram *
+popfile(Ram *dir, Fileinf fi)
+{
+	Ram *ent = (Ram *)emalloc(sizeof(Ram));
+	if (*fi.name=='\0')
+		return 0;
+	ent->busy = 1;
+	ent->open = 0;
+	ent->parent = dir;
+	ent->next = dir->child;
+	dir->child = ent;
+	ent->child = 0;
+	ent->qid.path = ++path;
+	ent->qid.vers = 0;
+	if(fi.mode&DMDIR)
+		ent->qid.type = QTDIR;
+	else
+		ent->qid.type = QTFILE;
+	ent->perm = fi.mode;
+	ent->name = estrdup(fi.name);
+	ent->atime = ent->mtime = fi.mdate;
+	ent->user = mapid(uidmap, fi.uid);
+	ent->group = mapid(gidmap, fi.gid);
+	ent->ndata = fi.size;
+	ent->data = fi.data;
+	ent->addr = fi.addr;
+	ent->replete |= replete;
+	return ent;
+}
+
+Ram *
+lookup(Ram *dir, char *name)
+{
+	Ram *r;
+
+	if (dir==0)
+		return 0;
+	for (r=dir->child; r; r=r->next){
+		if (r->busy==0 || strcmp(r->name, name)!=0)
+			continue;
+		return r;
+	}
+	return 0;
+}