Merge pull request #424 from ecsv/batadv-17.01

[feed/routing.git] / batman-adv / patches / 0056-batman-adv-Use-explicit-tvlv-padding-for-ELP-packets.patch

diff --git a/batman-adv/patches/0056-batman-adv-Use-explicit-tvlv-padding-for-ELP-packets.patch b/batman-adv/patches/0056-batman-adv-Use-explicit-tvlv-padding-for-ELP-packets.patch
new file mode 100644 (file)
index 0000000..44f68ce
--- /dev/null
+++ b/batman-adv/patches/0056-batman-adv-Use-explicit-tvlv-padding-for-ELP-packets.patch
@@ -0,0 +1,58 @@
+From: Sven Eckelmann <sven@narfation.org>
+Date: Tue, 30 Oct 2018 12:17:10 +0100
+Subject: [PATCH] batman-adv: Use explicit tvlv padding for ELP packets
+
+The announcement messages of batman-adv COMPAT_VERSION 15 have the
+possibility to announce additional information via a dynamic TVLV part.
+This part is optional for the ELP packets and currently not parsed by the
+Linux implementation. Still out-of-tree versions are using it to transport
+things like neighbor hashes to optimize the rebroadcast behavior.
+
+Since the ELP broadcast packets are smaller than the minimal ethernet
+packet, it often has to be padded. This is often done (as specified in
+RFC894) with octets of zero and thus work perfectly fine with the TVLV
+part (making it a zero length and thus empty). But not all ethernet
+compatible hardware seems to follow this advice. To avoid ambiguous
+situations when parsing the TVLV header, just force the 4 bytes (TVLV
+length + padding) after the required ELP header to zero.
+
+Fixes: a4b88af77e28 ("batman-adv: ELP - adding basic infrastructure")
+Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+
+Origin: backport, https://git.open-mesh.org/batman-adv.git/commit/974337ee9773c4bd0a2d5c322306cf2bea445e11
+---
+ net/batman-adv/bat_v_elp.c | 8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
+index 2ec0ecab0493ff88fdc01e55c8557de5b772e8bf..08c0809fca7de1fe51727652a2e870ddfa74dc13 100644
+--- a/net/batman-adv/bat_v_elp.c
++++ b/net/batman-adv/bat_v_elp.c
+@@ -338,21 +338,23 @@ out:
+  */
+ int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
+ {
++      static const size_t tvlv_padding = sizeof(__be32);
+       struct batadv_elp_packet *elp_packet;
+       unsigned char *elp_buff;
+       u32 random_seqno;
+       size_t size;
+       int res = -ENOMEM;
+ 
+-      size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN;
++      size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding;
+       hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
+       if (!hard_iface->bat_v.elp_skb)
+               goto out;
+ 
+       skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
+-      elp_buff = skb_put(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
++      elp_buff = skb_put(hard_iface->bat_v.elp_skb,
++                         BATADV_ELP_HLEN + tvlv_padding);
+       elp_packet = (struct batadv_elp_packet *)elp_buff;
+-      memset(elp_packet, 0, BATADV_ELP_HLEN);
++      memset(elp_packet, 0, BATADV_ELP_HLEN + tvlv_padding);
+ 
+       elp_packet->packet_type = BATADV_ELP;
+       elp_packet->version = BATADV_COMPAT_VERSION;