From 479df1769d51351d031482acaaf0c713726c05d1 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Tue, 24 Jul 2012 13:06:44 -0700 Subject: [PATCH] ofproto-dpif: Add more details to "ofproto/trace" output. There are many reasons why OFPP_NORMAL translation can drop packets, and it's often far from obvious why. This should make it easier to debug. Bug #12618. Signed-off-by: Ben Pfaff --- ofproto/ofproto-dpif.c | 51 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c index dc15c15b..c25c513c 100644 --- a/ofproto/ofproto-dpif.c +++ b/ofproto/ofproto-dpif.c @@ -243,6 +243,11 @@ struct action_xlate_ctx { * calling action_xlate_ctx_init(). */ void (*resubmit_hook)(struct action_xlate_ctx *, struct rule_dpif *rule); + /* If nonnull, flow translation calls this function to report some + * significant decision, e.g. to explain why OFPP_NORMAL translation + * dropped a packet. */ + void (*report_hook)(struct action_xlate_ctx *, const char *s); + /* If nonnull, flow translation credits the specified statistics to each * rule reached through a resubmit or OFPP_TABLE action. * @@ -299,6 +304,8 @@ static void compose_slow_path(const struct ofproto_dpif *, const struct flow *, const struct nlattr **actionsp, size_t *actions_lenp); +static void xlate_report(struct action_xlate_ctx *ctx, const char *s); + /* A subfacet (see "struct subfacet" below) has three possible installation * states: * @@ -5570,6 +5577,7 @@ action_xlate_ctx_init(struct action_xlate_ctx *ctx, ctx->may_learn = packet != NULL; ctx->tcp_flags = tcp_flags; ctx->resubmit_hook = NULL; + ctx->report_hook = NULL; ctx->resubmit_stats = NULL; } @@ -5696,6 +5704,14 @@ xlate_actions_for_side_effects(struct action_xlate_ctx *ctx, xlate_actions(ctx, ofpacts, ofpacts_len, &odp_actions); ofpbuf_uninit(&odp_actions); } + +static void +xlate_report(struct action_xlate_ctx *ctx, const char *s) +{ + if (ctx->report_hook) { + ctx->report_hook(ctx, s); + } +} /* OFPP_NORMAL implementation. */ @@ -6107,14 +6123,17 @@ lookup_input_bundle(const struct ofproto_dpif *ofproto, uint16_t in_port, * so in one special case. */ static bool -is_admissible(struct ofproto_dpif *ofproto, const struct flow *flow, - struct ofport_dpif *in_port, uint16_t vlan, tag_type *tags) +is_admissible(struct action_xlate_ctx *ctx, struct ofport_dpif *in_port, + uint16_t vlan) { + struct ofproto_dpif *ofproto = ctx->ofproto; + struct flow *flow = &ctx->flow; struct ofbundle *in_bundle = in_port->bundle; /* Drop frames for reserved multicast addresses * only if forward_bpdu option is absent. */ if (!ofproto->up.forward_bpdu && eth_addr_is_reserved(flow->dl_dst)) { + xlate_report(ctx, "packet has reserved destination MAC, dropping"); return false; } @@ -6122,11 +6141,12 @@ is_admissible(struct ofproto_dpif *ofproto, const struct flow *flow, struct mac_entry *mac; switch (bond_check_admissibility(in_bundle->bond, in_port, - flow->dl_dst, tags)) { + flow->dl_dst, &ctx->tags)) { case BV_ACCEPT: break; case BV_DROP: + xlate_report(ctx, "bonding refused admissibility, dropping"); return false; case BV_DROP_IF_MOVED: @@ -6134,6 +6154,8 @@ is_admissible(struct ofproto_dpif *ofproto, const struct flow *flow, if (mac && mac->port.p != in_bundle && (!is_gratuitous_arp(flow) || mac_entry_is_grat_arp_locked(mac))) { + xlate_report(ctx, "SLB bond thinks this packet looped back, " + "dropping"); return false; } break; @@ -6157,6 +6179,7 @@ xlate_normal(struct action_xlate_ctx *ctx) in_bundle = lookup_input_bundle(ctx->ofproto, ctx->flow.in_port, ctx->packet != NULL, &in_port); if (!in_bundle) { + xlate_report(ctx, "no input bundle, dropping"); return; } @@ -6169,6 +6192,7 @@ xlate_normal(struct action_xlate_ctx *ctx) "VLAN tag received on port %s", ctx->ofproto->up.name, in_bundle->name); } + xlate_report(ctx, "partial VLAN tag, dropping"); return; } @@ -6180,19 +6204,20 @@ xlate_normal(struct action_xlate_ctx *ctx) "%s, which is reserved exclusively for mirroring", ctx->ofproto->up.name, in_bundle->name); } + xlate_report(ctx, "input port is mirror output port, dropping"); return; } /* Check VLAN. */ vid = vlan_tci_to_vid(ctx->flow.vlan_tci); if (!input_vid_is_valid(vid, in_bundle, ctx->packet != NULL)) { + xlate_report(ctx, "disallowed VLAN VID for this input port, dropping"); return; } vlan = input_vid_to_vlan(in_bundle, vid); /* Check other admissibility requirements. */ - if (in_port && - !is_admissible(ctx->ofproto, &ctx->flow, in_port, vlan, &ctx->tags)) { + if (in_port && !is_admissible(ctx, in_port, vlan)) { return; } @@ -6206,11 +6231,15 @@ xlate_normal(struct action_xlate_ctx *ctx) &ctx->tags); if (mac) { if (mac->port.p != in_bundle) { + xlate_report(ctx, "forwarding to learned port"); output_normal(ctx, mac->port.p, vlan); + } else { + xlate_report(ctx, "learned port is input port, dropping"); } } else { struct ofbundle *bundle; + xlate_report(ctx, "no learned MAC for destination, flooding"); HMAP_FOR_EACH (bundle, hmap_node, &ctx->ofproto->bundles) { if (bundle != in_bundle && ofbundle_includes_vlan(bundle, vlan) @@ -6600,6 +6629,17 @@ trace_resubmit(struct action_xlate_ctx *ctx, struct rule_dpif *rule) trace_format_rule(result, ctx->table_id, ctx->recurse + 1, rule); } +static void +trace_report(struct action_xlate_ctx *ctx, const char *s) +{ + struct trace_ctx *trace = CONTAINER_OF(ctx, struct trace_ctx, ctx); + struct ds *result = trace->result; + + ds_put_char_multiple(result, '\t', ctx->recurse); + ds_put_cstr(result, s); + ds_put_char(result, '\n'); +} + static void ofproto_unixctl_trace(struct unixctl_conn *conn, int argc, const char *argv[], void *aux OVS_UNUSED) @@ -6750,6 +6790,7 @@ ofproto_trace(struct ofproto_dpif *ofproto, const struct flow *flow, action_xlate_ctx_init(&trace.ctx, ofproto, flow, initial_tci, rule, tcp_flags, packet); trace.ctx.resubmit_hook = trace_resubmit; + trace.ctx.report_hook = trace_report; xlate_actions(&trace.ctx, rule->up.ofpacts, rule->up.ofpacts_len, &odp_actions); -- 2.30.2