Merge the dev_clone and dev_clone_cred event handlers into a single

event handler, dev_clone, which accepts a credential argument.
Implementors of the event can ignore it if they're not interested,
and most do.  This avoids having multiple event handler types and
fall-back/precedence logic in devfs.

This changes the kernel API for /dev cloning, and may affect third
party packages containg cloning kernel modules.

Requested by:	phk
MFC after:	3 days

sys/cam/scsi/scsi_target.c

@@ -141,8 +141,8 @@ static void		targfreeccb(struct targ_softc *softc, union ccb *ccb);
 static struct targ_cmd_descr *
 			targgetdescr(struct targ_softc *softc);
 static periph_init_t	targinit;
-static void		targclone(void *arg, char *name, int namelen,
-				  struct cdev **dev);
+static void		targclone(void *arg, struct ucred *cred, char *name,
+				  int namelen, struct cdev **dev);
 static void		targasync(void *callback_arg, u_int32_t code,
 				  struct cam_path *path, void *arg);
 static void		abort_all_pending(struct targ_softc *softc);
@@ -1025,7 +1025,8 @@ targinit(void)
 }
 
 static void
-targclone(void *arg, char *name, int namelen, struct cdev **dev)
+targclone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	int u;
 

sys/coda/coda_fbsd.c

@@ -70,8 +70,8 @@ int     vcdebug = 1;
 #define VCDEBUG if (vcdebug) printf
 
 /* for DEVFS, using bpf & tun drivers as examples*/
-static void coda_fbsd_clone(void *arg, char *name, int namelen,
-    struct cdev **dev);
+static void coda_fbsd_clone(void *arg, struct ucred *cred, char *name,
+    int namelen, struct cdev **dev);
 
 static int
 codadev_modevent(module_t mod, int type, void *data)
@@ -105,8 +105,9 @@ static moduledata_t codadev_mod = {
 };
 DECLARE_MODULE(codadev, codadev_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
 
-static void coda_fbsd_clone(arg, name, namelen, dev)
+static void coda_fbsd_clone(arg, cred, name, namelen, dev)
     void *arg;
+    struct ucred *cred;
     char *name;
     int namelen;
     struct cdev **dev;

sys/dev/firewire/firewirereg.h

@@ -303,7 +303,7 @@ struct fw_bind *fw_bindlookup (struct firewire_comm *, uint16_t, uint32_t);
 void fw_drain_txq (struct firewire_comm *);
 int fwdev_makedev (struct firewire_softc *);
 int fwdev_destroydev (struct firewire_softc *);
-void fwdev_clone (void *, char *, int, struct cdev **);
+void fwdev_clone (void *, struct ucred *, char *, int, struct cdev **);
 
 extern int firewire_debug;
 extern devclass_t firewire_devclass;

sys/dev/firewire/fwdev.c

@@ -840,7 +840,8 @@ fwdev_destroydev(struct firewire_softc *sc)
 #if defined(__FreeBSD__) && __FreeBSD_version >= 500000
 #define NDEVTYPE 2
 void
-fwdev_clone(void *arg, char *name, int namelen, struct cdev **dev)
+fwdev_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	struct firewire_softc *sc;
 	char *devnames[NDEVTYPE] = {"fw", "fwmem"};

sys/dev/nmdm/nmdm.c

@@ -104,7 +104,8 @@ static struct clonedevs *nmdmclones;
 static TAILQ_HEAD(,nm_softc) nmdmhead = TAILQ_HEAD_INITIALIZER(nmdmhead);
 
 static void
-nmdm_clone(void *arg, char *name, int nameen, struct cdev **dev)
+nmdm_clone(void *arg, struct ucred *cred, char *name, int nameen,
+    struct cdev **dev)
 {
 	int i, unit;
 	char *p;

sys/dev/snp/snp.c

@@ -114,7 +114,7 @@ static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist);
 static struct clonedevs	  *snpclones;
 
 static struct tty	*snpdevtotty(struct cdev *dev);
-static void		snp_clone(void *arg, char *name,
+static void		snp_clone(void *arg, struct ucred *cred, char *name,
 			    int namelen, struct cdev **dev);
 static int		snp_detach(struct snoop *snp);
 static int		snp_down(struct snoop *snp);
@@ -627,8 +627,9 @@ snppoll(dev, events, td)
 }
 
 static void
-snp_clone(arg, name, namelen, dev)
+snp_clone(arg, cred, name, namelen, dev)
 	void *arg;
+	struct ucred *cred;
 	char *name;
 	int namelen;
 	struct cdev **dev;

sys/dev/sound/pcm/dsp.c

@@ -1130,7 +1130,8 @@ dsp_mmap(struct cdev *i_dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
  *    	if xN.i isn't busy, return its dev_t
  */
 static void
-dsp_clone(void *arg, char *name, int namelen, struct cdev **dev)
+dsp_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	struct cdev *pdev;
 	struct snddev_info *pcm_dev;

sys/dev/sound/pcm/mixer.c

@@ -486,7 +486,8 @@ mixer_ioctl(struct cdev *i_dev, u_long cmd, caddr_t arg, int mode, struct thread
 
 #ifdef USING_DEVFS
 static void
-mixer_clone(void *arg, char *name, int namelen, struct cdev **dev)
+mixer_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	struct snddev_info *sd;
 

sys/dev/vkbd/vkbd.c

@@ -124,7 +124,8 @@ typedef struct vkbd_state	vkbd_state_t;
  *****************************************************************************
  *****************************************************************************/
 
-static void		vkbd_dev_clone(void *, char *, int, struct cdev **);
+static void		vkbd_dev_clone(void *, struct ucred *, char *, int,
+			    struct cdev **);
 static d_open_t		vkbd_dev_open;
 static d_close_t	vkbd_dev_close;
 static d_read_t		vkbd_dev_read;
@@ -152,7 +153,8 @@ static struct clonedevs	*vkbd_dev_clones = NULL;
 
 /* Clone device */
 static void
-vkbd_dev_clone(void *arg, char *name, int namelen, struct cdev **dev)
+vkbd_dev_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	int	unit;
 

sys/fs/coda/coda_fbsd.c

@@ -70,8 +70,8 @@ int     vcdebug = 1;
 #define VCDEBUG if (vcdebug) printf
 
 /* for DEVFS, using bpf & tun drivers as examples*/
-static void coda_fbsd_clone(void *arg, char *name, int namelen,
-    struct cdev **dev);
+static void coda_fbsd_clone(void *arg, struct ucred *cred, char *name,
+    int namelen, struct cdev **dev);
 
 static int
 codadev_modevent(module_t mod, int type, void *data)
@@ -105,8 +105,9 @@ static moduledata_t codadev_mod = {
 };
 DECLARE_MODULE(codadev, codadev_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
 
-static void coda_fbsd_clone(arg, name, namelen, dev)
+static void coda_fbsd_clone(arg, cred, name, namelen, dev)
     void *arg;
+    struct ucred *cred;
     char *name;
     int namelen;
     struct cdev **dev;

sys/fs/devfs/devfs_vnops.c

@@ -705,13 +705,10 @@ devfs_lookupx(ap)
 		goto notfound;
 
 	cdev = NULL;
-	EVENTHANDLER_INVOKE(dev_clone_cred, td->td_ucred, pname,
-	    strlen(pname), &cdev);
-	if (cdev == NULL) {
-		EVENTHANDLER_INVOKE(dev_clone, pname, strlen(pname), &cdev);
-		if (cdev == NULL)
-			goto notfound;
-	}
+	EVENTHANDLER_INVOKE(dev_clone, td->td_ucred, pname, strlen(pname),
+	    &cdev);
+	if (cdev == NULL)
+		goto notfound;
 
 	devfs_populate(dmp);
 

sys/kern/tty_pty.c

@@ -720,7 +720,7 @@ static void
 ptc_drvinit(void *unused)
 {
 
-	EVENTHANDLER_REGISTER(dev_clone_cred, pty_clone, 0, 1000);
+	EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
 }
 
 SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,ptc_drvinit,NULL)

sys/kern/tty_tty.c

@@ -52,7 +52,8 @@ cttyopen(struct cdev *dev, int flag, int mode, struct thread *td)
 }
 
 static void
-ctty_clone(void *arg, char *name, int namelen, struct cdev **dev)
+ctty_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 
 	if (*dev != NULL)

sys/net/bpf.c

@@ -108,7 +108,7 @@ static int	bpf_setdlt(struct bpf_d *, u_int);
 static void	filt_bpfdetach(struct knote *);
 static int	filt_bpfread(struct knote *, long);
 static void	bpf_drvinit(void *);
-static void	bpf_clone(void *, char *, int, struct cdev **);
+static void	bpf_clone(void *, struct ucred *, char *, int, struct cdev **);
 static int	bpf_stats_sysctl(SYSCTL_HANDLER_ARGS);
 
 /*
@@ -1614,8 +1614,9 @@ bpf_setdlt(d, dlt)
 }
 
 static void
-bpf_clone(arg, name, namelen, dev)
+bpf_clone(arg, cred, name, namelen, dev)
 	void *arg;
+	struct ucred *cred;
 	char *name;
 	int namelen;
 	struct cdev **dev;

sys/net/if_tap.c

@@ -82,7 +82,8 @@
 static int		tapmodevent(module_t, int, void *);
 
 /* device */
-static void		tapclone(void *, char *, int, struct cdev **);
+static void		tapclone(void *, struct ucred *, char *, int,
+			    struct cdev **);
 static void		tapcreate(struct cdev *);
 
 /* network interface */
@@ -231,8 +232,9 @@ tapmodevent(mod, type, data)
  * We need to support two kind of devices - tap and vmnet
  */
 static void
-tapclone(arg, name, namelen, dev)
+tapclone(arg, cred, name, namelen, dev)
 	void	*arg;
+	struct ucred *cred;
 	char	*name;
 	int	 namelen;
 	struct cdev **dev;

sys/net/if_tun.c

@@ -107,7 +107,8 @@ static struct clonedevs *tunclones;
 static TAILQ_HEAD(,tun_softc)	tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
 
-static void	tunclone(void *arg, char *name, int namelen, struct cdev **dev);
+static void	tunclone(void *arg, struct ucred *cred, char *name,
+		    int namelen, struct cdev **dev);
 static void	tuncreate(struct cdev *dev);
 static int	tunifioctl(struct ifnet *, u_long, caddr_t);
 static int	tuninit(struct ifnet *);
@@ -136,7 +137,8 @@ static struct cdevsw tun_cdevsw = {
 };
 
 static void
-tunclone(void *arg, char *name, int namelen, struct cdev **dev)
+tunclone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	int u, i;
 

sys/netsmb/smb_dev.c

@@ -99,7 +99,8 @@ static struct cdevsw nsmb_cdevsw = {
 static eventhandler_tag nsmb_dev_tag;
 
 static void
-nsmb_dev_clone(void *arg, char *name, int namelen, struct cdev **dev)
+nsmb_dev_clone(void *arg, struct ucred *cred, char *name, int namelen,
+    struct cdev **dev)
 {
 	int u;
 

sys/sys/conf.h

@@ -68,7 +68,7 @@ struct cdev {
 	uid_t		si_uid;
 	gid_t		si_gid;
 	mode_t		si_mode;
-	struct ucred	*si_cred;
+	struct ucred	*si_cred;	/* cached clone-time credential */
 	u_int		si_drv0;
 	int		si_refcount;
 	LIST_ENTRY(cdev)	si_list;
@@ -279,15 +279,12 @@ void devfs_destroy(struct cdev *dev);
 #define		GID_GAMES	13
 #define		GID_DIALER	68
 
-typedef void (*dev_clone_fn)(void *arg, char *name, int namelen, struct cdev **result);
+typedef void (*dev_clone_fn)(void *arg, struct ucred *cred, char *name,
+	    int namelen, struct cdev **result);
 
 int dev_stdclone(char *_name, char **_namep, const char *_stem, int *_unit);
 EVENTHANDLER_DECLARE(dev_clone, dev_clone_fn);
 
-typedef void (*dev_clone_cred_fn)(void *arg, struct ucred *cred, char *name,
-	int namelen, struct cdev **result);
-EVENTHANDLER_DECLARE(dev_clone_cred, dev_clone_cred_fn);
-
 /* Stuff relating to kernel-dump */
 
 struct dumperinfo {