| Message ID | 557B5F4F.1060703@cococorp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Johannes Berg |
| Headers | show |
On Fri, 2015-06-12 at 15:38 -0700, Alexis Green wrote: > From: Jesse Jones <jjones@cococorp.com> > > When processing a PREQ or PREP it's critical to use the incoming SN. If > that is improperly done routing loops and other types of badness can > happen. But the code was always processing path messages for deactivated > paths. This path fixes that so that if we have a valid SN then we use it > to verify that it is a message we can accept. For reference the relevant > section of the standard is 13.10.8.4 which doesn't address the deactivated > path case at all. > > I also included a special case for when our peer reboots or restarts > networking. This is an important case because without it there can be a > very long delay before we accept path messages from that peer. It's also a > simple case and intimately associated with processing messages for > deactivated paths so I used one patch instead of two. Applied. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index 45485f3..3c5f76a 100755 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -79,6 +79,12 @@ static inline u16 u16_field_get(const u8 *preq_elem, int offset, bool ae) #define MSEC_TO_TU(x) (x*1000/1024) #define SN_GT(x, y) ((s32)(y - x) < 0) #define SN_LT(x, y) ((s32)(x - y) < 0) +#define MAX_SANE_SN_DELTA 32 + +static inline u32 SN_DELTA(u32 x, u32 y) +{ + return x >= y ? x - y : y - x; +} #define net_traversal_jiffies(s) \ msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) @@ -441,6 +447,26 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata, process = false; fresh_info = false; } + } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { + bool have_sn, newer_sn, bounced; + + have_sn = mpath->flags & MESH_PATH_SN_VALID; + newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); + bounced = have_sn && + (SN_DELTA(orig_sn, mpath->sn) > + MAX_SANE_SN_DELTA); + + if (!have_sn || newer_sn) { + /* if SN is newer than what we had + * then we can take it */; + } else if (bounced) { + /* if SN is way different than what + * we had then assume the other side + * rebooted or restarted */; + } else { + process = false; + fresh_info = false; + } } } else { mpath = mesh_path_add(sdata, orig_addr);