a

kern/devroot.c

@@ -0,0 +1,268 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"error.h"
+
+enum
+{
+	Qdir = 0,
+	Qboot = 0x1000,
+
+	Nrootfiles = 32,
+	Nbootfiles = 32,
+};
+
+typedef struct Dirlist Dirlist;
+struct Dirlist
+{
+	uint base;
+	Dirtab *dir;
+	uchar **data;
+	int ndir;
+	int mdir;
+};
+
+static Dirtab rootdir[Nrootfiles] = {
+	"#/",		{Qdir, 0, QTDIR},	0,		DMDIR|0555,
+	"boot",	{Qboot, 0, QTDIR},	0,		DMDIR|0555,
+};
+static uchar *rootdata[Nrootfiles];
+static Dirlist rootlist = 
+{
+	0,
+	rootdir,
+	rootdata,
+	2,
+	Nrootfiles
+};
+
+static Dirtab bootdir[Nbootfiles] = {
+	"boot",	{Qboot, 0, QTDIR},	0,		DMDIR|0555,
+};
+static uchar *bootdata[Nbootfiles];
+static Dirlist bootlist =
+{
+	Qboot,
+	bootdir,
+	bootdata,
+	1,
+	Nbootfiles
+};
+
+/*
+ *  add a file to the list
+ */
+static void
+addlist(Dirlist *l, char *name, uchar *contents, ulong len, int perm)
+{
+	Dirtab *d;
+
+	if(l->ndir >= l->mdir)
+		panic("too many root files");
+	l->data[l->ndir] = contents;
+	d = &l->dir[l->ndir];
+	strcpy(d->name, name);
+	d->length = len;
+	d->perm = perm;
+	d->qid.type = 0;
+	d->qid.vers = 0;
+	d->qid.path = ++l->ndir + l->base;
+	if(perm & DMDIR)
+		d->qid.type |= QTDIR;
+}
+
+/*
+ *  add a root file
+ */
+void
+addbootfile(char *name, uchar *contents, ulong len)
+{
+	addlist(&bootlist, name, contents, len, 0555);
+}
+
+/*
+ *  add a root directory
+ */
+static void
+addrootdir(char *name)
+{
+	addlist(&rootlist, name, nil, 0, DMDIR|0555);
+}
+
+static void
+rootreset(void)
+{
+	addrootdir("bin");
+	addrootdir("dev");
+	addrootdir("env");
+	addrootdir("fd");
+	addrootdir("mnt");
+	addrootdir("net");
+	addrootdir("net.alt");
+	addrootdir("proc");
+	addrootdir("root");
+	addrootdir("srv");
+}
+
+static Chan*
+rootattach(char *spec)
+{
+	return devattach('/', spec);
+}
+
+static int
+rootgen(Chan *c, char *name, Dirtab *dirt, int ndirt, int s, Dir *dp)
+{
+	int t;
+	Dirtab *d;
+	Dirlist *l;
+
+	USED(dirt);
+	USED(ndirt);
+
+	switch((int)c->qid.path){
+	case Qdir:
+		if(s == DEVDOTDOT){
+			Qid tqiddir = {Qdir, 0, QTDIR};
+			devdir(c, tqiddir, "#/", 0, eve, 0555, dp);
+			return 1;
+		}
+		return devgen(c, name, rootlist.dir, rootlist.ndir, s, dp);
+	case Qboot:
+		if(s == DEVDOTDOT){
+			Qid tqiddir = {Qdir, 0, QTDIR};
+			devdir(c, tqiddir, "#/", 0, eve, 0555, dp);
+			return 1;
+		}
+		return devgen(c, name, bootlist.dir, bootlist.ndir, s, dp);
+	default:
+		if(s == DEVDOTDOT){
+			Qid tqiddir = {Qdir, 0, QTDIR};
+			if((int)c->qid.path < Qboot)
+				devdir(c, tqiddir, "#/", 0, eve, 0555, dp);
+			else {
+				tqiddir.path = Qboot;
+				devdir(c, tqiddir, "#/", 0, eve, 0555, dp);
+			}
+			return 1;
+		}
+		if(s != 0)
+			return -1;
+		if((int)c->qid.path < Qboot){
+			t = c->qid.path-1;
+			l = &rootlist;
+		}else{
+			t = c->qid.path - Qboot - 1;
+			l = &bootlist;
+		}
+		if(t >= l->ndir)
+			return -1;
+if(t < 0){
+print("rootgen %llud %d %d\n", c->qid.path, s, t);
+panic("whoops");
+}
+		d = &l->dir[t];
+		devdir(c, d->qid, d->name, d->length, eve, d->perm, dp);
+		return 1;
+	}
+	return -1;
+}
+
+static Walkqid*
+rootwalk(Chan *c, Chan *nc, char **name, int nname)
+{
+	return devwalk(c,  nc, name, nname, nil, 0, rootgen);
+}
+
+static int
+rootstat(Chan *c, uchar *dp, int n)
+{
+	return devstat(c, dp, n, nil, 0, rootgen);
+}
+
+static Chan*
+rootopen(Chan *c, int omode)
+{
+	return devopen(c, omode, nil, 0, devgen);
+}
+
+/*
+ * sysremove() knows this is a nop
+ */
+static void
+rootclose(Chan *c)
+{
+	USED(c);
+}
+
+static long
+rootread(Chan *c, void *buf, long n, vlong off)
+{
+	ulong t;
+	Dirtab *d;
+	Dirlist *l;
+	uchar *data;
+	ulong offset = off;
+
+	t = c->qid.path;
+	switch(t){
+	case Qdir:
+	case Qboot:
+		return devdirread(c, buf, n, nil, 0, rootgen);
+	}
+
+	if(t<Qboot)
+		l = &rootlist;
+	else{
+		t -= Qboot;
+		l = &bootlist;
+	}
+
+	t--;
+	if(t >= l->ndir)
+		error(Egreg);
+
+	d = &l->dir[t];
+	data = l->data[t];
+	if(offset >= d->length)
+		return 0;
+	if(offset+n > d->length)
+		n = d->length - offset;
+	memmove(buf, data+offset, n);
+	return n;
+}
+
+static long
+rootwrite(Chan *c, void *v, long n, vlong o)
+{
+	USED(c);
+	USED(v);
+	USED(n);
+	USED(o);
+
+	error(Egreg);
+	return 0;
+}
+
+Dev rootdevtab = {
+	'/',
+	"root",
+
+	rootreset,
+	devinit,
+	devshutdown,
+	rootattach,
+	rootwalk,
+	rootstat,
+	rootopen,
+	devcreate,
+	rootclose,
+	rootread,
+	devbread,
+	rootwrite,
+	devbwrite,
+	devremove,
+	devwstat,
+};
+