[src/trunk]: src/sys/net Use a random hunique, instead of sending the pointer...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/8f5e030eb034
branches:  trunk
changeset: 834702:8f5e030eb034
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri Aug 24 17:06:29 2018 +0000

description:
Use a random hunique, instead of sending the pointer of the interface.
Tested via ATF.

diffstat:

 sys/net/if_pppoe.c |  64 ++++++++++++++++++++++++++++++++++++++++-------------
 1 files changed, 48 insertions(+), 16 deletions(-)

diffs (161 lines):

diff -r 0a978327e5ca -r 8f5e030eb034 sys/net/if_pppoe.c
--- a/sys/net/if_pppoe.c        Fri Aug 24 16:37:19 2018 +0000
+++ b/sys/net/if_pppoe.c        Fri Aug 24 17:06:29 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_pppoe.c,v 1.142 2018/08/13 09:29:13 maxv Exp $ */
+/* $NetBSD: if_pppoe.c,v 1.143 2018/08/24 17:06:29 maxv Exp $ */
 
 /*-
  * Copyright (c) 2002, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_pppoe.c,v 1.142 2018/08/13 09:29:13 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_pppoe.c,v 1.143 2018/08/24 17:06:29 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "pppoe.h"
@@ -56,6 +56,7 @@
 #include <sys/rwlock.h>
 #include <sys/mutex.h>
 #include <sys/psref.h>
+#include <sys/cprng.h>
 
 #include <net/if.h>
 #include <net/if_types.h>
@@ -157,6 +158,7 @@
        LIST_ENTRY(pppoe_softc) sc_list;
        struct ifnet *sc_eth_if;        /* ethernet interface we are using */
 
+       uint64_t sc_id;                 /* id of this softc, our hunique */
        int sc_state;                   /* discovery phase or session connected */
        struct ether_addr sc_dest;      /* hardware address of concentrator */
        uint16_t sc_session;            /* PPPoE session id */
@@ -293,6 +295,31 @@
        return error;
 }
 
+static void
+pppoe_softc_genid(uint64_t *id)
+{
+       struct pppoe_softc *sc;
+       uint64_t rndid;
+
+       rw_enter(&pppoe_softc_list_lock, RW_READER);
+
+       while (1) {
+               rndid = cprng_strong64();
+
+               sc = NULL;
+               LIST_FOREACH(sc, &pppoe_softc_list, sc_list) {
+                       if (sc->sc_id == rndid)
+                               break;
+               }
+               if (sc == NULL) {
+                       break;
+               }
+       }
+
+       rw_exit(&pppoe_softc_list_lock);
+       *id = rndid;
+}
+
 static int
 pppoe_clone_create(struct if_clone *ifc, int unit)
 {
@@ -301,6 +328,8 @@
 
        sc = malloc(sizeof(struct pppoe_softc), M_DEVBUF, M_WAITOK|M_ZERO);
 
+       pppoe_softc_genid(&sc->sc_id);
+
        if_initname(&sc->sc_sppp.pp_if, "pppoe", unit);
        sc->sc_sppp.pp_if.if_softc = sc;
        sc->sc_sppp.pp_if.if_mtu = PPPOE_MAXMTU;
@@ -428,7 +457,10 @@
 pppoe_find_softc_by_hunique(uint8_t *token, size_t len,
     struct ifnet *rcvif, krw_t lock)
 {
-       struct pppoe_softc *sc, *t;
+       struct pppoe_softc *sc;
+       uint64_t t;
+
+       CTASSERT(sizeof(t) == sizeof(sc->sc_id));
 
        rw_enter(&pppoe_softc_list_lock, RW_READER);
        if (LIST_EMPTY(&pppoe_softc_list)) {
@@ -436,14 +468,14 @@
                return NULL;
        }
 
-       if (len != sizeof sc) {
+       if (len != sizeof(sc->sc_id)) {
                rw_exit(&pppoe_softc_list_lock);
                return NULL;
        }
        memcpy(&t, token, len);
 
        LIST_FOREACH(sc, &pppoe_softc_list, sc_list) {
-               if (sc == t) {
+               if (sc->sc_id == t) {
                        PPPOE_LOCK(sc, lock);
                        break;
                }
@@ -1345,7 +1377,7 @@
                l2 = strlen(sc->sc_concentrator_name);
                len += sizeof(struct pppoetag) + l2;
        }
-       len += sizeof(struct pppoetag) + sizeof(sc);
+       len += sizeof(struct pppoetag) + sizeof(sc->sc_id);
        if (sc->sc_sppp.pp_if.if_mtu > PPPOE_MAXMTU) {
                len += sizeof(struct pppoetag) + 2;
        }
@@ -1373,9 +1405,9 @@
                p += l2;
        }
        PPPOE_ADD_16(p, PPPOE_TAG_HUNIQUE);
-       PPPOE_ADD_16(p, sizeof(sc));
-       memcpy(p, &sc, sizeof(sc));
-       p += sizeof(sc);
+       PPPOE_ADD_16(p, sizeof(sc->sc_id));
+       memcpy(p, &sc->sc_id, sizeof(sc->sc_id));
+       p += sizeof(sc->sc_id);
 
        if (sc->sc_sppp.pp_if.if_mtu > PPPOE_MAXMTU) {
                PPPOE_ADD_16(p, PPPOE_TAG_MAX_PAYLOAD);
@@ -1621,7 +1653,7 @@
        if (sc->sc_relay_sid_len > 0) {
                len += sizeof(struct pppoetag) + sc->sc_relay_sid_len;
        }
-       len += sizeof(struct pppoetag) + sizeof(sc);
+       len += sizeof(struct pppoetag) + sizeof(sc->sc_id);
        if (sc->sc_sppp.pp_if.if_mtu > PPPOE_MAXMTU) {
                len += sizeof(struct pppoetag) + 2;
        }
@@ -1655,9 +1687,9 @@
                p += sc->sc_relay_sid_len;
        }
        PPPOE_ADD_16(p, PPPOE_TAG_HUNIQUE);
-       PPPOE_ADD_16(p, sizeof(sc));
-       memcpy(p, &sc, sizeof(sc));
-       p += sizeof(sc);
+       PPPOE_ADD_16(p, sizeof(sc->sc_id));
+       memcpy(p, &sc->sc_id, sizeof(sc->sc_id));
+       p += sizeof(sc->sc_id);
 
        if (sc->sc_sppp.pp_if.if_mtu > PPPOE_MAXMTU) {
                PPPOE_ADD_16(p, PPPOE_TAG_MAX_PAYLOAD);
@@ -1723,9 +1755,9 @@
        p = mtod(m0, uint8_t *);
        PPPOE_ADD_HEADER(p, PPPOE_CODE_PADO, 0, len);
        PPPOE_ADD_16(p, PPPOE_TAG_ACCOOKIE);
-       PPPOE_ADD_16(p, sizeof(sc));
-       memcpy(p, &sc, sizeof(sc));
-       p += sizeof(sc);
+       PPPOE_ADD_16(p, sizeof(sc->sc_id));
+       memcpy(p, &sc->sc_id, sizeof(sc->sc_id));
+       p += sizeof(sc->sc_id);
        PPPOE_ADD_16(p, PPPOE_TAG_HUNIQUE);
        PPPOE_ADD_16(p, sc->sc_hunique_len);
        memcpy(p, sc->sc_hunique, sc->sc_hunique_len);