git: a77facd27368 - main - ifnet: consistently call hooks when the interface gets up.

The branch main has been updated by melifaro:

URL: https://cgit.FreeBSD.org/src/commit/?id=a77facd27368f618520d25391cfce11149879a41

commit a77facd27368f618520d25391cfce11149879a41
Author:     Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2023-06-01 11:44:15 +0000
Commit:     Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2023-06-01 11:44:19 +0000

    ifnet: consistently call hooks when the interface gets up.
    
    Some context on the current IPv6 interface setup & address management:
    
    There are two data path for IPv6 initialisation in context of assigning
     LL addresses:
    1) Userland explicitly requests IFF_UP for the interface w/o any addresses.
    if_up() then calls in6_if_up(), which calls in6_ifattach().
    The latter sets up some initial ND/IN6 state and disables IPv6 for the
    interface if it’s not loopback. If the interface is loopback, then it
    adds ::1/128 and LL addresses via in6_ifattach_loopback().
    Then, devd notification is generated (if the VNET is the default one),
    which triggers rc.network ifconfig_up(), causing ifdisabled to be removed
    via SIOCSIFINFO_IN6 from ifconfig. The kernel SIOCSIFINFO_IN6 handler
    calls in6_if_up() once again and it assigns the interface link-local address.
    
    2) Userland adds IPv4 or IPv6 address to the interface. SIOCAIFADDR[_IN6]
    kernel handler calls IPv4/IPv6 protocol handler to add the address.
    Both then call if_ioctl() with SIOCSIFADDR. Ethernet/loopback ioctl handlers
    silently sets IFF_UP for the interface. Finally, if.c:ifioctl() wrapper code
    compares old and new interface flags and, if IFF_UP is added, it explicitly
    calls in6_if_up(), which adds link-local address if either the original
    address is IPv6 or the interface is loopback.
    
    In the latter case, “formal” interface-up notifications are missing.
    The kernel does not trigger event handler event, does not call carp hook
    and does not provide any userland notification.
    
    This diff unifies the event handling in both scenarios, providing the
    necessary notifications to the kernel and userland.
    
    Reviewed By: kp
    Differential Revision: https://reviews.freebsd.org/D40332
    MFC after:      2 weeks
---
 sys/net/if.c              | 36 +++++++-----------------------------
 sys/netinet6/in6.c        | 14 ++++++++++++++
 sys/netlink/route/iface.c |  4 +---
 3 files changed, 22 insertions(+), 32 deletions(-)

diff --git a/sys/net/if.c b/sys/net/if.c
index af9758a39324..975f4498073e 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -278,7 +278,6 @@ static void	if_attachdomain1(struct ifnet *);
 static int	ifconf(u_long, caddr_t);
 static void	if_input_default(struct ifnet *, struct mbuf *);
 static int	if_requestencap_default(struct ifnet *, struct if_encap_req *);
-static void	if_route(struct ifnet *, int flag, int fam);
 static int	if_setflag(struct ifnet *, int, int, int *, int);
 static int	if_transmit_default(struct ifnet *ifp, struct mbuf *m);
 static void	if_unroute(struct ifnet *, int flag, int fam);
@@ -2141,26 +2140,6 @@ if_unroute(struct ifnet *ifp, int flag, int fam)
 	rt_ifmsg(ifp, IFF_UP);
 }
 
-/*
- * Mark an interface up and notify protocols of
- * the transition.
- */
-static void
-if_route(struct ifnet *ifp, int flag, int fam)
-{
-
-	KASSERT(flag == IFF_UP, ("if_route: flag != IFF_UP"));
-
-	ifp->if_flags |= flag;
-	getmicrotime(&ifp->if_lastchange);
-	if (ifp->if_carp)
-		(*carp_linkstate_p)(ifp);
-	rt_ifmsg(ifp, IFF_UP);
-#ifdef INET6
-	in6_if_up(ifp);
-#endif
-}
-
 void	(*vlan_link_state_p)(struct ifnet *);	/* XXX: private from if_vlan */
 void	(*vlan_trunk_cap_p)(struct ifnet *);		/* XXX: private from if_vlan */
 struct ifnet *(*vlan_trunkdev_p)(struct ifnet *);
@@ -2246,7 +2225,11 @@ void
 if_up(struct ifnet *ifp)
 {
 
-	if_route(ifp, IFF_UP, AF_UNSPEC);
+	ifp->if_flags |= IFF_UP;
+	getmicrotime(&ifp->if_lastchange);
+	if (ifp->if_carp)
+		(*carp_linkstate_p)(ifp);
+	rt_ifmsg(ifp, IFF_UP);
 	EVENTHANDLER_INVOKE(ifnet_event, ifp, IFNET_EVENT_UP);
 }
 
@@ -3109,13 +3092,8 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 	    cmd != SIOCSIFDSTADDR && cmd != SIOCSIFNETMASK)
 		error = (*ifp->if_ioctl)(ifp, cmd, data);
 
-	if ((oif_flags ^ ifp->if_flags) & IFF_UP) {
-#ifdef INET6
-		if (ifp->if_flags & IFF_UP)
-			in6_if_up(ifp);
-#endif
-	}
-
+	if (!(oif_flags & IFF_UP) && (ifp->if_flags & IFF_UP))
+		if_up(ifp);
 out_ref:
 	if_rele(ifp);
 out_noref:
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index 3d967e9a40c7..0ef640c5c4bf 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -2049,6 +2049,20 @@ in6_if_up(struct ifnet *ifp)
 	in6_ifattach(ifp, NULL);
 }
 
+static void
+in6_ifevent(void *arg __unused, struct ifnet *ifp, int event)
+{
+	if (event == IFNET_EVENT_UP)
+		in6_if_up(ifp);
+}
+
+static void
+in6_init(void *arg __unused)
+{
+	EVENTHANDLER_REGISTER(ifnet_event, in6_ifevent, NULL, EVENTHANDLER_PRI_ANY);
+}
+SYSINIT(in6_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, in6_init, NULL);
+
 int
 in6if_do_dad(struct ifnet *ifp)
 {
diff --git a/sys/netlink/route/iface.c b/sys/netlink/route/iface.c
index 2f70325ce9ef..5e0295e7fe52 100644
--- a/sys/netlink/route/iface.c
+++ b/sys/netlink/route/iface.c
@@ -1312,10 +1312,8 @@ rtnl_handle_addr(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt)
 		error = EAFNOSUPPORT;
 	}
 
-#ifdef INET6
 	if (error == 0 && !(if_flags & IFF_UP) && (if_getflags(ifp) & IFF_UP))
-		in6_if_up(ifp);
-#endif
+		if_up(ifp);
 
 	if_rele(ifp);