X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/cb3231590a3c94ab4375e2228bd5e86b0cf1ad7e..94ff46dc2849db4d43eaaf144872decc522aafb4:/bsd/kern/kern_control.c

diff --git a/bsd/kern/kern_control.c b/bsd/kern/kern_control.c
index dede2e6e8..e41d1f103 100644
--- a/bsd/kern/kern_control.c
+++ b/bsd/kern/kern_control.c
@@ -93,6 +93,7 @@ struct ctl_cb {
 	void                    *userdata;
 	struct sockaddr_ctl     sac;
 	u_int32_t               usecount;
+	u_int32_t               kcb_usecount;
 };
 
 #ifndef ROUNDUP64
@@ -351,6 +352,27 @@ ctl_sofreelastref(struct socket *so)
 	return 0;
 }
 
+/*
+ * Use this function to serialize calls into the kctl subsystem
+ */
+static void
+ctl_kcb_increment_use_count(struct ctl_cb *kcb, lck_mtx_t *mutex_held)
+{
+	LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
+	while (kcb->kcb_usecount > 0) {
+		msleep(&kcb->kcb_usecount, mutex_held, PSOCK | PCATCH, "kcb_usecount", NULL);
+	}
+	kcb->kcb_usecount++;
+}
+
+static void
+clt_kcb_decrement_use_count(struct ctl_cb *kcb)
+{
+	assert(kcb->kcb_usecount != 0);
+	kcb->kcb_usecount--;
+	wakeup_one((caddr_t)&kcb->kcb_usecount);
+}
+
 static int
 ctl_detach(struct socket *so)
 {
@@ -360,6 +382,9 @@ ctl_detach(struct socket *so)
 		return 0;
 	}
 
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	if (kcb->kctl != NULL && kcb->kctl->bind != NULL &&
 	    kcb->userdata != NULL && !(so->so_state & SS_ISCONNECTED)) {
 		// The unit was bound, but not connected
@@ -374,6 +399,7 @@ ctl_detach(struct socket *so)
 
 	soisdisconnected(so);
 	so->so_flags |= SOF_PCBCLEARING;
+	clt_kcb_decrement_use_count(kcb);
 	return 0;
 }
 
@@ -522,9 +548,12 @@ ctl_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
 		panic("ctl_bind so_pcb null\n");
 	}
 
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	error = ctl_setup_kctl(so, nam, p);
 	if (error) {
-		return error;
+		goto out;
 	}
 
 	if (kcb->kctl == NULL) {
@@ -532,13 +561,16 @@ ctl_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
 	}
 
 	if (kcb->kctl->bind == NULL) {
-		return EINVAL;
+		error = EINVAL;
+		goto out;
 	}
 
 	socket_unlock(so, 0);
 	error = (*kcb->kctl->bind)(kcb->kctl->kctlref, &kcb->sac, &kcb->userdata);
 	socket_lock(so, 0);
 
+out:
+	clt_kcb_decrement_use_count(kcb);
 	return error;
 }
 
@@ -552,9 +584,12 @@ ctl_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 		panic("ctl_connect so_pcb null\n");
 	}
 
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	error = ctl_setup_kctl(so, nam, p);
 	if (error) {
-		return error;
+		goto out;
 	}
 
 	if (kcb->kctl == NULL) {
@@ -596,6 +631,8 @@ end:
 		kctlstat.kcs_conn_fail++;
 		lck_mtx_unlock(ctl_mtx);
 	}
+out:
+	clt_kcb_decrement_use_count(kcb);
 	return error;
 }
 
@@ -605,6 +642,8 @@ ctl_disconnect(struct socket *so)
 	struct ctl_cb   *kcb = (struct ctl_cb *)so->so_pcb;
 
 	if ((kcb = (struct ctl_cb *)so->so_pcb)) {
+		lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+		ctl_kcb_increment_use_count(kcb, mtx_held);
 		struct kctl             *kctl = kcb->kctl;
 
 		if (kctl && kctl->disconnect) {
@@ -628,6 +667,7 @@ ctl_disconnect(struct socket *so)
 		kctlstat.kcs_gencnt++;
 		lck_mtx_unlock(ctl_mtx);
 		socket_lock(so, 0);
+		clt_kcb_decrement_use_count(kcb);
 	}
 	return 0;
 }
@@ -694,11 +734,20 @@ ctl_sbrcv_trim(struct socket *so)
 static int
 ctl_usr_rcvd(struct socket *so, int flags)
 {
+	int                     error = 0;
 	struct ctl_cb           *kcb = (struct ctl_cb *)so->so_pcb;
 	struct kctl                     *kctl;
 
+	if (kcb == NULL) {
+		return ENOTCONN;
+	}
+
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	if ((kctl = kcb->kctl) == NULL) {
-		return EINVAL;
+		error = EINVAL;
+		goto out;
 	}
 
 	if (kctl->rcvd) {
@@ -709,7 +758,9 @@ ctl_usr_rcvd(struct socket *so, int flags)
 
 	ctl_sbrcv_trim(so);
 
-	return 0;
+out:
+	clt_kcb_decrement_use_count(kcb);
+	return error;
 }
 
 static int
@@ -730,6 +781,9 @@ ctl_send(struct socket *so, int flags, struct mbuf *m,
 		error = ENOTCONN;
 	}
 
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	if (error == 0 && (kctl = kcb->kctl) == NULL) {
 		error = EINVAL;
 	}
@@ -749,6 +803,8 @@ ctl_send(struct socket *so, int flags, struct mbuf *m,
 	if (error != 0) {
 		OSIncrementAtomic64((SInt64 *)&kctlstat.kcs_send_fail);
 	}
+	clt_kcb_decrement_use_count(kcb);
+
 	return error;
 }
 
@@ -769,6 +825,9 @@ ctl_send_list(struct socket *so, int flags, struct mbuf *m,
 		error = ENOTCONN;
 	}
 
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	if (error == 0 && (kctl = kcb->kctl) == NULL) {
 		error = EINVAL;
 	}
@@ -808,6 +867,8 @@ ctl_send_list(struct socket *so, int flags, struct mbuf *m,
 	if (error != 0) {
 		OSIncrementAtomic64((SInt64 *)&kctlstat.kcs_send_list_fail);
 	}
+	clt_kcb_decrement_use_count(kcb);
+
 	return error;
 }
 
@@ -1234,16 +1295,21 @@ ctl_ctloutput(struct socket *so, struct sockopt *sopt)
 		return EINVAL;
 	}
 
+	lck_mtx_t *mtx_held = socket_getlock(so, PR_F_WILLUNLOCK);
+	ctl_kcb_increment_use_count(kcb, mtx_held);
+
 	switch (sopt->sopt_dir) {
 	case SOPT_SET:
 		if (kctl->setopt == NULL) {
-			return ENOTSUP;
+			error = ENOTSUP;
+			goto out;
 		}
 		if (sopt->sopt_valsize != 0) {
 			MALLOC(data, void *, sopt->sopt_valsize, M_TEMP,
 			    M_WAITOK | M_ZERO);
 			if (data == NULL) {
-				return ENOMEM;
+				error = ENOMEM;
+				goto out;
 			}
 			error = sooptcopyin(sopt, data,
 			    sopt->sopt_valsize, sopt->sopt_valsize);
@@ -1263,14 +1329,16 @@ ctl_ctloutput(struct socket *so, struct sockopt *sopt)
 
 	case SOPT_GET:
 		if (kctl->getopt == NULL) {
-			return ENOTSUP;
+			error = ENOTSUP;
+			goto out;
 		}
 
 		if (sopt->sopt_valsize && sopt->sopt_val) {
 			MALLOC(data, void *, sopt->sopt_valsize, M_TEMP,
 			    M_WAITOK | M_ZERO);
 			if (data == NULL) {
-				return ENOMEM;
+				error = ENOMEM;
+				goto out;
 			}
 			/*
 			 * 4108337 - copy user data in case the
@@ -1306,6 +1374,9 @@ ctl_ctloutput(struct socket *so, struct sockopt *sopt)
 		}
 		break;
 	}
+
+out:
+	clt_kcb_decrement_use_count(kcb);
 	return error;
 }