git: 1865ebfb12dd - main - if_bridge: change MTU for new members

The branch main has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=1865ebfb12ddaf3d0ff1458e6152b3cb1f1bdee8

commit 1865ebfb12ddaf3d0ff1458e6152b3cb1f1bdee8
Author:     Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2022-06-25 11:39:44 +0000
Commit:     Kristof Provost <kp@FreeBSD.org>
CommitDate: 2022-06-27 06:27:27 +0000

    if_bridge: change MTU for new members
    
    Rather than reject new bridge members because they have the wrong MTU
    change it to match the bridge. If that fails, reject the new interface.
    
    PR:     264883
    Different Revision:     https://reviews.freebsd.org/D35597
---
 sys/net/if_bridge.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index dd65188bcc4a..39085fa440e8 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -1266,9 +1266,21 @@ bridge_ioctl_add(struct bridge_softc *sc, void *arg)
 	if (CK_LIST_EMPTY(&sc->sc_iflist))
 		sc->sc_ifp->if_mtu = ifs->if_mtu;
 	else if (sc->sc_ifp->if_mtu != ifs->if_mtu) {
-		if_printf(sc->sc_ifp, "invalid MTU: %u(%s) != %u\n",
-		    ifs->if_mtu, ifs->if_xname, sc->sc_ifp->if_mtu);
-		return (EINVAL);
+		struct ifreq ifr;
+
+		snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s",
+		    ifs->if_xname);
+		ifr.ifr_mtu = sc->sc_ifp->if_mtu;
+
+		error = (*ifs->if_ioctl)(ifs,
+		    SIOCSIFMTU, (caddr_t)&ifr);
+		if (error != 0) {
+			log(LOG_NOTICE, "%s: invalid MTU: %u for"
+			    " new member %s\n", sc->sc_ifp->if_xname,
+			    ifr.ifr_mtu,
+			    ifs->if_xname);
+			return (EINVAL);
+		}
 	}
 
 	bif = malloc(sizeof(*bif), M_DEVBUF, M_NOWAIT|M_ZERO);