Ovs ko passes odp key and packet to userspace. Next packet is extracted into flow, which is the input for xlate to generate wc. At last, ukey(= odp_key/wc) is installed into datapath. If the odp_key is not consistant with packet extracted flow. The ukey will be wrong.
commit [1] was created to fix inconsistance caused by bad tcp header. commit [2] was cretaed to fix inconsistance caused by bad ip header. There is no guarantee of the consistance of odp_key and packet flow. So it is necessary to make the check to prevent from installing wrong ukey. [1] 1f5749c790accd98dbcafdaefc40bf5e52d7c672 [2] 79349cbab0b2a755140eedb91833ad2760520a83 Signed-off-by: Cheng Li <lic...@chinatelecom.cn> --- Notes: v2: Leverage avoid_caching to avoid ukey install. ofproto/ofproto-dpif-upcall.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c index b5cbeed87..bd93f0981 100644 --- a/ofproto/ofproto-dpif-upcall.c +++ b/ofproto/ofproto-dpif-upcall.c @@ -66,6 +66,7 @@ COVERAGE_DEFINE(upcall_flow_limit_reduced); COVERAGE_DEFINE(upcall_flow_limit_scaled); COVERAGE_DEFINE(upcall_ukey_contention); COVERAGE_DEFINE(upcall_ukey_replace); +COVERAGE_DEFINE(upcall_packet_flow_inconsistant); /* A thread that reads upcalls from dpif, forwards each upcall's packet, * and possibly sets up a kernel flow as a cache. */ @@ -840,6 +841,7 @@ recv_upcalls(struct handler *handler) struct dpif_upcall dupcalls[UPCALL_MAX_BATCH]; struct upcall upcalls[UPCALL_MAX_BATCH]; struct flow flows[UPCALL_MAX_BATCH]; + struct flow odp_key_flow; size_t n_upcalls, i; n_upcalls = 0; @@ -903,6 +905,8 @@ recv_upcalls(struct handler *handler) upcall->out_tun_key = dupcall->out_tun_key; upcall->actions = dupcall->actions; + /* Save odp flow before overwrite. */ + memcpy(&odp_key_flow, flow, sizeof odp_key_flow); pkt_metadata_from_flow(&dupcall->packet.md, flow); flow_extract(&dupcall->packet, flow); @@ -912,6 +916,12 @@ recv_upcalls(struct handler *handler) goto cleanup; } + if (!flow_equal_except(&odp_key_flow, flow, &upcall->wc)) { + /* If odp flow is not consistant with flow extract from packet, + * bad ukey/mask will be installed. */ + COVERAGE_INC(upcall_packet_flow_inconsistant); + upcall->xout.avoid_caching = true; + } n_upcalls++; continue; @@ -1376,6 +1386,10 @@ should_install_flow(struct udpif *udpif, struct upcall *upcall) return false; } + if (upcall->xout.avoid_caching) { + return false; + } + atomic_read_relaxed(&udpif->flow_limit, &flow_limit); if (udpif_get_n_flows(udpif) >= flow_limit) { COVERAGE_INC(upcall_flow_limit_hit); -- 2.39.3 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev