commit cef0d2f8a4aa3181901589321d0b289890d923a2
parent 31e59616e044a57c3829a225239160a5bd1dcba1
Author: Michael Teichgräber <mt4swm@googlemail.com>
Date: Sun, 27 Dec 2009 09:48:22 -0800
To make it possible to log into 9vx using drawterm a
device #¤ (devcap) is needed, otherwise auth_chuid()
will fail, because it cannot open #¤/capuse.
This patch adds `9/port/devcap.c' from Plan 9 to
9vx/a, with only a few adaptions (see a/devcap.ed).
R=rsc_swtch, rsc
CC=codebot
http://codereview.appspot.com/151042
Committer: Russ Cox <rsc@swtch.com>
Diffstat:
4 files changed, 316 insertions(+), 0 deletions(-)
diff --git a/src/9vx/Makefrag b/src/9vx/Makefrag
@@ -66,6 +66,7 @@ PLAN9_A_OBJS = \
convS2M.o \
convM2S.o \
dev.o \
+ devcap.o \
devcons.o \
devdraw.o \
devdup.o \
diff --git a/src/9vx/a/devcap.c b/src/9vx/a/devcap.c
@@ -0,0 +1,286 @@
+#include "u.h"
+#include "lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "error.h"
+
+#include "libsec.h"
+
+enum
+{
+ Hashlen= SHA1dlen,
+ Maxhash= 256,
+};
+
+/*
+ * if a process knows cap->cap, it can change user
+ * to capabilty->user.
+ */
+typedef struct Caphash Caphash;
+struct Caphash
+{
+ Caphash *next;
+ char hash[Hashlen];
+ ulong ticks;
+};
+
+struct
+{
+ QLock l;
+ Caphash *first;
+ int nhash;
+} capalloc;
+
+enum
+{
+ Qdir,
+ Qhash,
+ Quse,
+};
+
+/* caphash must be last */
+Dirtab capdir[] =
+{
+ ".", {Qdir,0,QTDIR}, 0, DMDIR|0500,
+ "capuse", {Quse}, 0, 0222,
+ "caphash", {Qhash}, 0, 0200,
+};
+int ncapdir = nelem(capdir);
+
+static Chan*
+capattach(char *spec)
+{
+ return devattach(L'¤', spec);
+}
+
+static Walkqid*
+capwalk(Chan *c, Chan *nc, char **name, int nname)
+{
+ return devwalk(c, nc, name, nname, capdir, ncapdir, devgen);
+}
+
+static void
+capremove(Chan *c)
+{
+ if(iseve() && c->qid.path == Qhash)
+ ncapdir = nelem(capdir)-1;
+ else
+ error(Eperm);
+}
+
+
+static int
+capstat(Chan *c, uchar *db, int n)
+{
+ return devstat(c, db, n, capdir, ncapdir, devgen);
+}
+
+/*
+ * if the stream doesn't exist, create it
+ */
+static Chan*
+capopen(Chan *c, int omode)
+{
+ if(c->qid.type & QTDIR){
+ if(omode != OREAD)
+ error(Ebadarg);
+ c->mode = omode;
+ c->flag |= COPEN;
+ c->offset = 0;
+ return c;
+ }
+
+ switch((ulong)c->qid.path){
+ case Qhash:
+ if(!iseve())
+ error(Eperm);
+ break;
+ }
+
+ c->mode = openmode(omode);
+ c->flag |= COPEN;
+ c->offset = 0;
+ return c;
+}
+
+/*
+static char*
+hashstr(uchar *hash)
+{
+ static char buf[2*Hashlen+1];
+ int i;
+
+ for(i = 0; i < Hashlen; i++)
+ sprint(buf+2*i, "%2.2ux", hash[i]);
+ buf[2*Hashlen] = 0;
+ return buf;
+}
+ */
+
+static Caphash*
+remcap(uchar *hash)
+{
+ Caphash *t, **l;
+
+ qlock(&capalloc.l);
+
+ /* find the matching capability */
+ for(l = &capalloc.first; *l != nil;){
+ t = *l;
+ if(memcmp(hash, t->hash, Hashlen) == 0)
+ break;
+ l = &t->next;
+ }
+ t = *l;
+ if(t != nil){
+ capalloc.nhash--;
+ *l = t->next;
+ }
+ qunlock(&capalloc.l);
+
+ return t;
+}
+
+/* add a capability, throwing out any old ones */
+static void
+addcap(uchar *hash)
+{
+ Caphash *p, *t, **l;
+
+ p = smalloc(sizeof *p);
+ memmove(p->hash, hash, Hashlen);
+ p->next = nil;
+ p->ticks = msec();
+
+ qlock(&capalloc.l);
+
+ /* trim extras */
+ while(capalloc.nhash >= Maxhash){
+ t = capalloc.first;
+ if(t == nil)
+ panic("addcap");
+ capalloc.first = t->next;
+ free(t);
+ capalloc.nhash--;
+ }
+
+ /* add new one */
+ for(l = &capalloc.first; *l != nil; l = &(*l)->next)
+ ;
+ *l = p;
+ capalloc.nhash++;
+
+ qunlock(&capalloc.l);
+}
+
+static void
+capclose(Chan *c)
+{
+}
+
+static long
+capread(Chan *c, void *va, long n, vlong vl)
+{
+ switch((ulong)c->qid.path){
+ case Qdir:
+ return devdirread(c, va, n, capdir, ncapdir, devgen);
+
+ default:
+ error(Eperm);
+ break;
+ }
+ return n;
+}
+
+static long
+capwrite(Chan *c, void *va, long n, vlong vl)
+{
+ Caphash *p;
+ char *cp;
+ uchar hash[Hashlen];
+ char *key, *from, *to;
+ char err[256];
+
+ switch((ulong)c->qid.path){
+ case Qhash:
+ if(!iseve())
+ error(Eperm);
+ if(n < Hashlen)
+ error(Eshort);
+ memmove(hash, va, Hashlen);
+ addcap(hash);
+ break;
+
+ case Quse:
+ /* copy key to avoid a fault in hmac_xx */
+ cp = nil;
+ if(waserror()){
+ free(cp);
+ nexterror();
+ }
+ cp = smalloc(n+1);
+ memmove(cp, va, n);
+ cp[n] = 0;
+
+ from = cp;
+ key = strrchr(cp, '@');
+ if(key == nil)
+ error(Eshort);
+ *key++ = 0;
+
+ hmac_sha1((uchar*)from, strlen(from), (uchar*)key, strlen(key), hash, nil);
+
+ p = remcap(hash);
+ if(p == nil){
+ snprint(err, sizeof err, "invalid capability %s@%s", from, key);
+ error(err);
+ }
+
+ /* if a from user is supplied, make sure it matches */
+ to = strchr(from, '@');
+ if(to == nil){
+ to = from;
+ } else {
+ *to++ = 0;
+ if(strcmp(from, up->user) != 0)
+ error("capability must match user");
+ }
+
+ /* set user id */
+ kstrdup(&up->user, to);
+ up->basepri = PriNormal;
+
+ free(p);
+ free(cp);
+ poperror();
+ break;
+
+ default:
+ error(Eperm);
+ break;
+ }
+
+ return n;
+}
+
+Dev capdevtab = {
+ L'¤',
+ "cap",
+
+ devreset,
+ devinit,
+ devshutdown,
+ capattach,
+ capwalk,
+ capstat,
+ capopen,
+ devcreate,
+ capclose,
+ capread,
+ devbread,
+ capwrite,
+ devbwrite,
+ capremove,
+ devwstat
+};
diff --git a/src/9vx/a/devcap.ed b/src/9vx/a/devcap.ed
@@ -0,0 +1,27 @@
+197c
+capwrite(Chan *c, void *va, long n, vlong vl)
+.
+183c
+capread(Chan *c, void *va, long n, vlong vl)
+.
+178c
+capclose(Chan *c)
+.
+174c
+ qunlock(&capalloc.l);
+.
+156c
+ qlock(&capalloc.l);
+.
+154c
+ p->ticks = msec();
+.
+140c
+ qunlock(&capalloc.l);
+.
+126c
+ qlock(&capalloc.l);
+.
+30c
+ QLock l;
+.
diff --git a/src/9vx/devtab.c b/src/9vx/devtab.c
@@ -22,6 +22,7 @@ extern Dev procdevtab;
extern Dev mntloopdevtab;
extern Dev dupdevtab;
extern Dev sddevtab;
+extern Dev capdevtab;
Dev *devtab[] = {
&rootdevtab, /* must be first */
@@ -41,6 +42,7 @@ Dev *devtab[] = {
&ssldevtab,
&tlsdevtab,
&sddevtab,
+ &capdevtab,
0
};
