From 94f885db2a18b9c6d36b31f1f4af7c1c820fac60 Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Fri, 27 Jul 2018 15:26:55 +0300 Subject: [PATCH] net: dcb: For wild-card lookups, use priority -1, not 0 [ Upstream commit 08193d1a893c802c4b807e4d522865061f4e9f4f ] The function dcb_app_lookup walks the list of specified DCB APP entries, looking for one that matches a given criteria: ifindex, selector, protocol ID and optionally also priority. The "don't care" value for priority is set to 0, because that priority has not been allowed under CEE regime, which predates the IEEE standardization. Under IEEE, 0 is a valid priority number. But because dcb_app_lookup considers zero a wild card, attempts to add an APP entry with priority 0 fail when other entries exist for a given ifindex / selector / PID triplet. Fix by changing the wild-card value to -1. Signed-off-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/dcb/dcbnl.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c index bae7d78aa068..fbeacbc2be5d 100644 --- a/net/dcb/dcbnl.c +++ b/net/dcb/dcbnl.c @@ -1765,7 +1765,7 @@ static struct dcb_app_type *dcb_app_lookup(const struct dcb_app *app, if (itr->app.selector == app->selector && itr->app.protocol == app->protocol && itr->ifindex == ifindex && - (!prio || itr->app.priority == prio)) + ((prio == -1) || itr->app.priority == prio)) return itr; } @@ -1800,7 +1800,8 @@ u8 dcb_getapp(struct net_device *dev, struct dcb_app *app) u8 prio = 0; spin_lock_bh(&dcb_lock); - if ((itr = dcb_app_lookup(app, dev->ifindex, 0))) + itr = dcb_app_lookup(app, dev->ifindex, -1); + if (itr) prio = itr->app.priority; spin_unlock_bh(&dcb_lock); @@ -1828,7 +1829,8 @@ int dcb_setapp(struct net_device *dev, struct dcb_app *new) spin_lock_bh(&dcb_lock); /* Search for existing match and replace */ - if ((itr = dcb_app_lookup(new, dev->ifindex, 0))) { + itr = dcb_app_lookup(new, dev->ifindex, -1); + if (itr) { if (new->priority) itr->app.priority = new->priority; else { @@ -1861,7 +1863,8 @@ u8 dcb_ieee_getapp_mask(struct net_device *dev, struct dcb_app *app) u8 prio = 0; spin_lock_bh(&dcb_lock); - if ((itr = dcb_app_lookup(app, dev->ifindex, 0))) + itr = dcb_app_lookup(app, dev->ifindex, -1); + if (itr) prio |= 1 << itr->app.priority; spin_unlock_bh(&dcb_lock);