BSD: When applying RA base information, ensure flags are correct

For some resaon, under privsep only, SIOCGIFINFO_IN6 returns 0
in flags even though the kernel seems to set it correctly.
SIOCSIFINFO_IN6 *will* overwrite flags regardless, so ensure
it has the correct value for dhcpcd.

diff --git a/src/if-bsd.c b/src/if-bsd.c
index b14650ce537f57db77a2fd4df87f38f7e19e58e2..e47f308a0dbf1453c5c91f8729d43ed800e7fb83 100644 (file)
--- a/src/if-bsd.c
+++ b/src/if-bsd.c
@@ -1585,23 +1585,71 @@ inet6_sysctl(int code, int val, int action)
 }
 #endif
 
+#if defined(SIOCSIFINFO_IN6) || defined(SIOCSIFINFO_FLAGS)
+static uint32_t
+if_if6flags(const struct interface *ifp, uint32_t oflags)
+{
+       int flags = (int)oflags;
+
+#ifdef ND6_IFF_AUTO_LINKLOCAL
+       /* Unlike the kernel,
+        * dhcpcd make make a stable private address. */
+       flags &= ~ND6_IFF_AUTO_LINKLOCAL;
+#endif
+
+#ifdef ND6_IFF_IFDISABLED
+       /* Ensure the interface is not disabled. */
+       flags &= ~ND6_IFF_IFDISABLED;
+#endif
+
+#ifdef ND6_IFF_PERFORMNUD
+       /* NUD is kind of essential. */
+       flags |= ND6_IFF_PERFORMNUD;
+#endif
+
+       /*
+        * If not doing autoconf, don't disable the kernel from doing it.
+        * If we need to, we should have another option actively disable it.
+        */
+#ifdef ND6_IFF_ACCEPT_RTADV
+       if (ifp->options->options & DHCPCD_IPV6RS)
+               flags &= ~ND6_IFF_ACCEPT_RTADV;
+#ifdef ND6_IFF_OVERRIDE_RTADV
+       if (ifp->options->options & DHCPCD_IPV6RS)
+               flags |= ND6_IFF_OVERRIDE_RTADV;
+#endif
+#endif
+
+       return (uint32_t)flags;
+}
+#endif
+
 int
 if_applyra(const struct ra *rap)
 {
 #ifdef SIOCSIFINFO_IN6
-       struct in6_ndireq ndi = { .ndi.chlim = 0 };
+       struct in6_ndireq nd;
        struct dhcpcd_ctx *ctx = rap->iface->ctx;
        int error;
 
-       strlcpy(ndi.ifname, rap->iface->name, sizeof(ndi.ifname));
-       if (if_ioctl6(ctx, SIOCGIFINFO_IN6, &ndi, sizeof(ndi)) == -1)
+       memset(&nd, 0, sizeof(nd));
+       strlcpy(nd.ifname, rap->iface->name, sizeof(nd.ifname));
+       if (if_ioctl6(ctx, SIOCGIFINFO_IN6, &nd, sizeof(nd)) == -1)
                return -1;
 
-       ndi.ndi.linkmtu = rap->mtu;
-       ndi.ndi.chlim = rap->hoplimit;
-       ndi.ndi.retrans = rap->retrans;
-       ndi.ndi.basereachable = rap->reachable;
-       error = if_ioctl6(ctx, SIOCSIFINFO_IN6, &ndi, sizeof(ndi));
+       nd.ndi.linkmtu = rap->mtu;
+       nd.ndi.chlim = rap->hoplimit;
+       nd.ndi.retrans = rap->retrans;
+       nd.ndi.basereachable = rap->reachable;
+       /*
+        * Under privsep, flags are returned as zero - no idea why.
+        * SIOCSIFINFO_IN6 will replace the flags anyway so force them
+        * to our idea again.
+        */
+       if (nd.ndi.flags == 0)
+               nd.ndi.flags = if_if6flags(rap->iface, nd.ndi.flags);
+
+       error = if_ioctl6(ctx, SIOCSIFINFO_IN6, &nd, sizeof(nd));
        if (error == -1 && errno == EINVAL) {
                /*
                 * Very likely that this is caused by a dodgy MTU
@@ -1610,8 +1658,8 @@ if_applyra(const struct ra *rap)
                 * Doesn't really matter as we fix the MTU against the
                 * routes we add as not all OS support SIOCSIFINFO_IN6.
                 */
-               ndi.ndi.linkmtu = 0;
-               error = if_ioctl6(ctx, SIOCSIFINFO_IN6, &ndi, sizeof(ndi));
+               nd.ndi.linkmtu = 0;
+               error = if_ioctl6(ctx, SIOCSIFINFO_IN6, &nd, sizeof(nd));
        }
        return error;
 #else
@@ -1815,7 +1863,7 @@ if_setup_inet6(const struct interface *ifp)
        int s;
 #ifdef ND6_NDI_FLAGS
        struct in6_ndireq nd;
-       int flags;
+       uint32_t flags;
 #endif
 
        priv = (struct priv *)ifp->ctx->priv;
@@ -1825,42 +1873,12 @@ if_setup_inet6(const struct interface *ifp)
        memset(&nd, 0, sizeof(nd));
        strlcpy(nd.ifname, ifp->name, sizeof(nd.ifname));
        if (ioctl(s, SIOCGIFINFO_IN6, &nd) == -1)
-               logerr("%s: SIOCGIFINFO_FLAGS", ifp->name);
-       flags = (int)nd.ndi.flags;
-#endif
-
-#ifdef ND6_IFF_AUTO_LINKLOCAL
-       /* Unlike the kernel,
-        * dhcpcd make make a stable private address. */
-       flags &= ~ND6_IFF_AUTO_LINKLOCAL;
-#endif
+               logerr("%s: SIOCGIFINFO_IN6", ifp->name);
 
-#ifdef ND6_IFF_PERFORMNUD
-       /* NUD is kind of essential. */
-       flags |= ND6_IFF_PERFORMNUD;
-#endif
+       flags = if_if6flags(ifp, nd.ndi.flags);
 
-#ifdef ND6_IFF_IFDISABLED
-       /* Ensure the interface is not disabled. */
-       flags &= ~ND6_IFF_IFDISABLED;
-#endif
-
-       /*
-        * If not doing autoconf, don't disable the kernel from doing it.
-        * If we need to, we should have another option actively disable it.
-        */
-#ifdef ND6_IFF_ACCEPT_RTADV
-       if (ifp->options->options & DHCPCD_IPV6RS)
-               flags &= ~ND6_IFF_ACCEPT_RTADV;
-#ifdef ND6_IFF_OVERRIDE_RTADV
-       if (ifp->options->options & DHCPCD_IPV6RS)
-               flags |= ND6_IFF_OVERRIDE_RTADV;
-#endif
-#endif
-
-#ifdef ND6_NDI_FLAGS
-       if (nd.ndi.flags != (uint32_t)flags) {
-               nd.ndi.flags = (uint32_t)flags;
+       if (nd.ndi.flags != flags) {
+               nd.ndi.flags = flags;
                if (if_ioctl6(ifp->ctx, SIOCSIFINFO_FLAGS,
                    &nd, sizeof(nd)) == -1)
                        logerr("%s: SIOCSIFINFO_FLAGS", ifp->name);