The branch main has been updated by kp:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=85967694b4590a436c56a061b397620e342784ae

commit 85967694b4590a436c56a061b397620e342784ae
Author:     Lexi Winter <l...@hemlock.eden.le-fay.org>
AuthorDate: 2025-04-05 14:04:21 +0000
Commit:     Kristof Provost <k...@freebsd.org>
CommitDate: 2025-04-09 07:39:01 +0000

    bridge: store a bridge_iflist pointer in ifnet
    
    currently, bridge stores a pointer to its softc in ifnet.  this means
    that when processing a packet, it needs to walk the bridge's member list
    to find the bridge_iflist for the interface the packet came from.
    
    instead, store a pointer to the bridge_iflist in ifnet, and add a
    pointer from bridge_iflist back to the bridge_softc.  this means given
    an ifnet, we always have both the softc and the bridge_iflist without a
    list walk.
    
    there are two places outside if_bridge that treat ifnet->if_bridge as
    something other than an opaque pointer: bridgestp, and netinet.  add two
    function pointers exported from if_bridge to handle those cases.
    
    bump __FreeBSD_version as this is technically a KABI break.
    
    Reviewed by:    kp
---
 sys/net/bridgestp.c    |   4 +-
 sys/net/if_bridge.c    | 132 ++++++++++++++++++++++++++++++++++---------------
 sys/net/if_bridgevar.h |   2 +
 sys/net/if_ethersubr.c |   2 +
 sys/netinet/if_ether.c |   7 +--
 sys/sys/param.h        |   2 +-
 6 files changed, 103 insertions(+), 46 deletions(-)

diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index c67f1efe3d88..b5a863641de7 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -57,6 +57,7 @@
 #include <net/if_types.h>
 #include <net/if_llc.h>
 #include <net/if_media.h>
+#include <net/if_bridgevar.h>
 #include <net/vnet.h>
 
 #include <netinet/in.h>
@@ -2059,6 +2060,7 @@ bstp_reinit(struct bstp_state *bs)
        mif = NULL;
        bridgeptr = LIST_FIRST(&bs->bs_bplist)->bp_ifp->if_bridge;
        KASSERT(bridgeptr != NULL, ("Invalid bridge pointer"));
+       KASSERT(bridge_same_p != NULL, ("if_bridge not loaded"));
        /*
         * Search through the Ethernet adapters and find the one with the
         * lowest value. Make sure the adapter which we take the MAC address
@@ -2070,7 +2072,7 @@ bstp_reinit(struct bstp_state *bs)
                if (ifp->if_type != IFT_ETHER && ifp->if_type != IFT_L2VLAN)
                        continue;       /* Not Ethernet */
 
-               if (ifp->if_bridge != bridgeptr)
+               if (!bridge_same_p(ifp->if_bridge, bridgeptr))
                        continue;       /* Not part of our bridge */
 
                if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index 5cb4a033e325..fdfec024ef07 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -238,12 +238,15 @@
 #define BRIDGE_RT_LOCK_OR_NET_EPOCH_ASSERT(_sc)        \
            MPASS(in_epoch(net_epoch_preempt) || mtx_owned(&(_sc)->sc_rt_mtx))
 
+struct bridge_softc;
+
 /*
  * Bridge interface list entry.
  */
 struct bridge_iflist {
        CK_LIST_ENTRY(bridge_iflist) bif_next;
        struct ifnet            *bif_ifp;       /* member if */
+       struct bridge_softc     *bif_sc;        /* parent bridge */
        struct bstp_port        bif_stp;        /* STP state */
        uint32_t                bif_flags;      /* member if flags */
        int                     bif_savedcaps;  /* saved capabilities */
@@ -314,6 +317,8 @@ static void bridge_set_ifcap(struct bridge_softc *, struct 
bridge_iflist *,
 static void    bridge_ifdetach(void *arg __unused, struct ifnet *);
 static void    bridge_init(void *);
 static void    bridge_dummynet(struct mbuf *, struct ifnet *);
+static bool    bridge_same(const void *, const void *);
+static void    *bridge_get_softc(struct ifnet *);
 static void    bridge_stop(struct ifnet *, int);
 static int     bridge_transmit(struct ifnet *, struct mbuf *);
 #ifdef ALTQ
@@ -658,6 +663,8 @@ bridge_modevent(module_t mod, int type, void *data)
        switch (type) {
        case MOD_LOAD:
                bridge_dn_p = bridge_dummynet;
+               bridge_same_p = bridge_same;
+               bridge_get_softc_p = bridge_get_softc;
                bridge_detach_cookie = EVENTHANDLER_REGISTER(
                    ifnet_departure_event, bridge_ifdetach, NULL,
                    EVENTHANDLER_PRI_ANY);
@@ -666,6 +673,8 @@ bridge_modevent(module_t mod, int type, void *data)
                EVENTHANDLER_DEREGISTER(ifnet_departure_event,
                    bridge_detach_cookie);
                bridge_dn_p = NULL;
+               bridge_same_p = NULL;
+               bridge_get_softc_p = NULL;
                break;
        default:
                return (EOPNOTSUPP);
@@ -740,6 +749,43 @@ bridge_reassign(struct ifnet *ifp, struct vnet *newvnet, 
char *arg)
 }
 #endif
 
+/*
+ * bridge_get_softc:
+ *
+ * Return the bridge softc for an ifnet.
+ */
+static void *
+bridge_get_softc(struct ifnet *ifp)
+{
+       struct bridge_iflist *bif;
+
+       NET_EPOCH_ASSERT();
+
+       bif = ifp->if_bridge;
+       if (bif == NULL)
+               return (NULL);
+       return (bif->bif_sc);
+}
+
+/*
+ * bridge_same:
+ *
+ * Return true if two interfaces are in the same bridge.  This is only used by
+ * bridgestp via bridge_same_p.
+ */
+static bool
+bridge_same(const void *bifap, const void *bifbp)
+{
+       const struct bridge_iflist *bifa = bifap, *bifb = bifbp;
+
+       NET_EPOCH_ASSERT();
+
+       if (bifa == NULL || bifb == NULL)
+               return (false);
+
+       return (bifa->bif_sc == bifb->bif_sc);
+}
+
 /*
  * bridge_clone_create:
  *
@@ -1116,16 +1162,8 @@ bridge_lookup_member(struct bridge_softc *sc, const char 
*name)
 static struct bridge_iflist *
 bridge_lookup_member_if(struct bridge_softc *sc, struct ifnet *member_ifp)
 {
-       struct bridge_iflist *bif;
-
        BRIDGE_LOCK_OR_NET_EPOCH_ASSERT(sc);
-
-       CK_LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
-               if (bif->bif_ifp == member_ifp)
-                       return (bif);
-       }
-
-       return (NULL);
+       return (member_ifp->if_bridge);
 }
 
 static void
@@ -1257,11 +1295,13 @@ bridge_ioctl_add(struct bridge_softc *sc, void *arg)
                if (ifs == bif->bif_ifp)
                        return (EBUSY);
 
-       if (ifs->if_bridge == sc)
-               return (EEXIST);
+       if (ifs->if_bridge) {
+               struct bridge_iflist *sbif = ifs->if_bridge;
+               if (sbif->bif_sc == sc)
+                       return (EEXIST);
 
-       if (ifs->if_bridge != NULL)
                return (EBUSY);
+       }
 
        switch (ifs->if_type) {
        case IFT_ETHER:
@@ -1336,6 +1376,7 @@ bridge_ioctl_add(struct bridge_softc *sc, void *arg)
        if (bif == NULL)
                return (ENOMEM);
 
+       bif->bif_sc = sc;
        bif->bif_ifp = ifs;
        bif->bif_flags = IFBIF_LEARNING | IFBIF_DISCOVER;
        bif->bif_savedcaps = ifs->if_capenable;
@@ -1352,7 +1393,7 @@ bridge_ioctl_add(struct bridge_softc *sc, void *arg)
                EVENTHANDLER_INVOKE(iflladdr_event, sc->sc_ifp);
        }
 
-       ifs->if_bridge = sc;
+       ifs->if_bridge = bif;
        ifs->if_bridge_output = bridge_output;
        ifs->if_bridge_input = bridge_input;
        ifs->if_bridge_linkstate = bridge_linkstate;
@@ -1979,8 +2020,11 @@ bridge_ioctl_stxhc(struct bridge_softc *sc, void *arg)
 static void
 bridge_ifdetach(void *arg __unused, struct ifnet *ifp)
 {
-       struct bridge_softc *sc = ifp->if_bridge;
-       struct bridge_iflist *bif;
+       struct bridge_iflist *bif = ifp->if_bridge;
+       struct bridge_softc *sc = NULL;
+
+       if (bif)
+               sc = bif->bif_sc;
 
        if (ifp->if_flags & IFF_RENAMING)
                return;
@@ -1994,11 +2038,7 @@ bridge_ifdetach(void *arg __unused, struct ifnet *ifp)
        /* Check if the interface is a bridge member */
        if (sc != NULL) {
                BRIDGE_LOCK(sc);
-
-               bif = bridge_lookup_member_if(sc, ifp);
-               if (bif != NULL)
-                       bridge_delete_member(sc, bif, 1);
-
+               bridge_delete_member(sc, bif, 1);
                BRIDGE_UNLOCK(sc);
                return;
        }
@@ -2136,9 +2176,11 @@ bridge_enqueue(struct bridge_softc *sc, struct ifnet 
*dst_ifp, struct mbuf *m)
 static void
 bridge_dummynet(struct mbuf *m, struct ifnet *ifp)
 {
-       struct bridge_softc *sc;
+       struct bridge_iflist *bif = ifp->if_bridge;
+       struct bridge_softc *sc = NULL;
 
-       sc = ifp->if_bridge;
+       if (bif)
+               sc = bif->bif_sc;
 
        /*
         * The packet didnt originate from a member interface. This should only
@@ -2175,6 +2217,7 @@ bridge_output(struct ifnet *ifp, struct mbuf *m, struct 
sockaddr *sa,
     struct rtentry *rt)
 {
        struct ether_header *eh;
+       struct bridge_iflist *sbif;
        struct ifnet *bifp, *dst_if;
        struct bridge_softc *sc;
        uint16_t vlan;
@@ -2187,12 +2230,13 @@ bridge_output(struct ifnet *ifp, struct mbuf *m, struct 
sockaddr *sa,
                        return (0);
        }
 
+       sbif = ifp->if_bridge;
+       sc = sbif->bif_sc;
+       bifp = sc->sc_ifp;
+
        eh = mtod(m, struct ether_header *);
-       sc = ifp->if_bridge;
        vlan = VLANTAGOF(m);
 
-       bifp = sc->sc_ifp;
-
        /*
         * If bridge is down, but the original output interface is up,
         * go ahead and send out that interface.  Otherwise, the packet
@@ -2503,7 +2547,7 @@ drop:
 static struct mbuf *
 bridge_input(struct ifnet *ifp, struct mbuf *m)
 {
-       struct bridge_softc *sc;
+       struct bridge_softc *sc = NULL;
        struct bridge_iflist *bif, *bif2;
        struct ifnet *bifp;
        struct ether_header *eh;
@@ -2516,7 +2560,10 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
        eh = mtod(m, struct ether_header *);
        vlan = VLANTAGOF(m);
 
-       sc = ifp->if_bridge;
+       bif = ifp->if_bridge;
+       if (bif)
+               sc = bif->bif_sc;
+
        if (sc == NULL) {
                /*
                 * This packet originated from the bridge itself, so it must
@@ -2553,10 +2600,6 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
                m_freem(m);
                return (NULL);
        }
-       bif = bridge_lookup_member_if(sc, ifp);
-       if (bif == NULL) {
-               return (m);
-       }
 
        bridge_span(sc, m);
 
@@ -3329,10 +3372,16 @@ bridge_rtnode_destroy(struct bridge_softc *sc, struct 
bridge_rtnode *brt)
 static void
 bridge_rtable_expire(struct ifnet *ifp, int age)
 {
-       struct bridge_softc *sc = ifp->if_bridge;
+       struct bridge_iflist *bif = NULL;
+       struct bridge_softc *sc = NULL;
        struct bridge_rtnode *brt;
 
        CURVNET_SET(ifp->if_vnet);
+
+       bif = ifp->if_bridge;
+       if (bif)
+               sc = bif->bif_sc;
+       MPASS(sc != NULL);
        BRIDGE_RT_LOCK(sc);
 
        /*
@@ -3362,7 +3411,8 @@ bridge_rtable_expire(struct ifnet *ifp, int age)
 static void
 bridge_state_change(struct ifnet *ifp, int state)
 {
-       struct bridge_softc *sc = ifp->if_bridge;
+       struct bridge_iflist *bif = ifp->if_bridge;
+       struct bridge_softc *sc = bif->bif_sc;
        static const char *stpstates[] = {
                "disabled",
                "listening",
@@ -3877,20 +3927,20 @@ dropit:
 static void
 bridge_linkstate(struct ifnet *ifp)
 {
-       struct bridge_softc *sc = ifp->if_bridge;
+       struct bridge_softc *sc = NULL;
        struct bridge_iflist *bif;
        struct epoch_tracker et;
 
        NET_EPOCH_ENTER(et);
 
-       bif = bridge_lookup_member_if(sc, ifp);
-       if (bif == NULL) {
-               NET_EPOCH_EXIT(et);
-               return;
-       }
-       bridge_linkcheck(sc);
+       bif = ifp->if_bridge;
+       if (bif)
+               sc = bif->bif_sc;
 
-       bstp_linkstate(&bif->bif_stp);
+       if (sc != NULL) {
+               bridge_linkcheck(sc);
+               bstp_linkstate(&bif->bif_stp);
+       }
 
        NET_EPOCH_EXIT(et);
 }
diff --git a/sys/net/if_bridgevar.h b/sys/net/if_bridgevar.h
index 01ac96e8d5b0..1f762bc4ecf9 100644
--- a/sys/net/if_bridgevar.h
+++ b/sys/net/if_bridgevar.h
@@ -320,5 +320,7 @@ struct ifbpstpconf {
 } while (0)
 
 extern void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
+extern bool (*bridge_same_p)(const void *, const void *);
+extern void *(*bridge_get_softc_p)(struct ifnet *);
 
 #endif /* _KERNEL */
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index ddaa94414ca5..2397b5ff2090 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -110,6 +110,8 @@ void        (*vlan_input_p)(struct ifnet *, struct mbuf *);
 
 /* if_bridge(4) support */
 void   (*bridge_dn_p)(struct mbuf *, struct ifnet *);
+bool   (*bridge_same_p)(const void *, const void *);
+void   *(*bridge_get_softc_p)(struct ifnet *);
 
 /* if_lagg(4) support */
 struct mbuf *(*lagg_input_ethernet_p)(struct ifnet *, struct mbuf *); 
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 88da1b139b1f..dc6ef343662d 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -56,6 +56,7 @@
 #include <net/if_dl.h>
 #include <net/if_private.h>
 #include <net/if_types.h>
+#include <net/if_bridgevar.h>
 #include <net/netisr.h>
 #include <net/ethernet.h>
 #include <net/route.h>
@@ -832,7 +833,7 @@ in_arpinput(struct mbuf *m)
         * when we have clusters of interfaces).
         */
        CK_LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
-               if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) ||
+               if (((bridged && bridge_same_p(ia->ia_ifp->if_bridge, 
ifp->if_bridge)) ||
                    ia->ia_ifp == ifp) &&
                    itaddr.s_addr == ia->ia_addr.sin_addr.s_addr &&
                    (ia->ia_ifa.ifa_carp == NULL ||
@@ -842,7 +843,7 @@ in_arpinput(struct mbuf *m)
                }
        }
        CK_LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
-               if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) ||
+               if (((bridged && bridge_same_p(ia->ia_ifp->if_bridge, 
ifp->if_bridge)) ||
                    ia->ia_ifp == ifp) &&
                    isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
                        ifa_ref(&ia->ia_ifa);
@@ -850,7 +851,7 @@ in_arpinput(struct mbuf *m)
                }
 
 #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia)                          \
-  (ia->ia_ifp->if_bridge == ifp->if_softc &&                           \
+  (bridge_get_softc_p(ia->ia_ifp) == ifp->if_softc &&                  \
   !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) &&     \
   addr == ia->ia_addr.sin_addr.s_addr)
        /*
diff --git a/sys/sys/param.h b/sys/sys/param.h
index b08a83ccc25b..4b7b4853e19d 100644
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -73,7 +73,7 @@
  * cannot include sys/param.h and should only be updated here.
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 1500035
+#define __FreeBSD_version 1500036
 
 /*
  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,

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