This Linux kernel change "mac80211: allocate tailroom for forwarded mesh packets" is included in the Linux 5.0 release. This change is authored by Felix Fietkau <nbd [at] nbd.name> on Fri Feb 22 13:21:15 2019 +0100. The commit for this change in Linux stable tree is 51d0af2 (patch).
mac80211: allocate tailroom for forwarded mesh packets Forwarded packets enter the tx path through ieee80211_add_pending_skb, which skips the ieee80211_skb_resize call. Fixes WARN_ON in ccmp_encrypt_skb and resulting packet loss. Cc: [email protected] Signed-off-by: Felix Fietkau <[email protected]> Signed-off-by: Johannes Berg <[email protected]>
There are 7 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.
net/mac80211/rx.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index bb4d71e..c2a6da5 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2644,6 +2644,7 @@ static void ieee80211_deliver_skb_to_local_stack(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata = rx->sdata; struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; u16 ac, q, hdrlen; + int tailroom = 0; hdr = (struct ieee80211_hdr *) skb->data; hdrlen = ieee80211_hdrlen(hdr->frame_control); @@ -2732,8 +2733,12 @@ static void ieee80211_deliver_skb_to_local_stack(struct sk_buff *skb, if (!ifmsh->mshcfg.dot11MeshForwarding) goto out; + if (sdata->crypto_tx_tailroom_needed_cnt) + tailroom = IEEE80211_ENCRYPT_TAILROOM; + fwd_skb = skb_copy_expand(skb, local->tx_headroom + - sdata->encrypt_headroom, 0, GFP_ATOMIC); + sdata->encrypt_headroom, + tailroom, GFP_ATOMIC); if (!fwd_skb) goto out;