From 79eee1eb33caa89ced4a03c2f486d94cd1b6930f Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Fri, 2 Apr 2010 15:12:42 -0700 Subject: [PATCH] ofproto: Make OFPFC_MODIFY and OFPFC_MODIFY_STRICT add a flow if no match. OpenFlow 1.0 says that OFPFC_MODIFY and OFPFC_MODIFY_STRICT are supposed to add the specified flow to the flow table if it does not already contain one that matches. Reported-by: Natasha Gude Bug #2506. --- ofproto/ofproto.c | 270 +++++++++++++++++++++++++++++++++------------- 1 file changed, 198 insertions(+), 72 deletions(-) diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c index 9efc96eb7..fd1256fc7 100644 --- a/ofproto/ofproto.c +++ b/ofproto/ofproto.c @@ -108,6 +108,9 @@ struct rule { struct list list; /* OpenFlow actions. + * + * 'n_actions' is the number of elements in the 'actions' array. A single + * action may take up more more than one element's worth of space. * * A subrule has no actions (it uses the super-rule's actions). */ int n_actions; @@ -2874,9 +2877,18 @@ update_stats(struct ofproto *ofproto, struct rule *rule, } } +/* Implements OFPFC_ADD and the cases for OFPFC_MODIFY and OFPFC_MODIFY_STRICT + * in which no matching flow already exists in the flow table. + * + * Adds the flow specified by 'ofm', which is followed by 'n_actions' + * ofp_actions, to 'p''s flow table. Returns 0 on success or an OpenFlow error + * code as encoded by ofp_mkerr() on failure. + * + * 'ofconn' is used to retrieve the packet buffer specified in ofm->buffer_id, + * if any. */ static int add_flow(struct ofproto *p, struct ofconn *ofconn, - struct ofp_flow_mod *ofm, size_t n_actions) + const struct ofp_flow_mod *ofm, size_t n_actions) { struct ofpbuf *packet; struct rule *rule; @@ -2914,112 +2926,224 @@ add_flow(struct ofproto *p, struct ofconn *ofconn, return error; } -static int -modify_flow(struct ofproto *p, const struct ofp_flow_mod *ofm, - size_t n_actions, uint16_t command, struct rule *rule) -{ - if (rule_is_hidden(rule)) { - return 0; - } - - if (command == OFPFC_DELETE) { - long long int now = time_msec(); - send_flow_removed(p, rule, now, OFPRR_DELETE); - rule_remove(p, rule); - } else { - size_t actions_len = n_actions * sizeof *rule->actions; - - rule->flow_cookie = ofm->cookie; - if (n_actions == rule->n_actions - && !memcmp(ofm->actions, rule->actions, actions_len)) - { - return 0; - } - - free(rule->actions); - rule->actions = xmemdup(ofm->actions, actions_len); - rule->n_actions = n_actions; - - if (rule->cr.wc.wildcards) { - COVERAGE_INC(ofproto_mod_wc_flow); - p->need_revalidate = true; - } else { - rule_update_actions(p, rule); - } - } - - return 0; -} - -static int -modify_flows_strict(struct ofproto *p, const struct ofp_flow_mod *ofm, - size_t n_actions, uint16_t command) +static struct rule * +find_flow_strict(struct ofproto *p, const struct ofp_flow_mod *ofm) { - struct rule *rule; uint32_t wildcards; flow_t flow; flow_from_match(&flow, &wildcards, &ofm->match); - rule = rule_from_cls_rule(classifier_find_rule_exactly( + return rule_from_cls_rule(classifier_find_rule_exactly( &p->cls, &flow, wildcards, ntohs(ofm->priority))); +} - if (rule) { - if (command == OFPFC_DELETE - && ofm->out_port != htons(OFPP_NONE) - && !rule_has_out_port(rule, ofm->out_port)) { - return 0; - } +static int +send_buffered_packet(struct ofproto *ofproto, struct ofconn *ofconn, + struct rule *rule, const struct ofp_flow_mod *ofm) +{ + struct ofpbuf *packet; + uint16_t in_port; + flow_t flow; + int error; - modify_flow(p, ofm, n_actions, command, rule); + if (ofm->buffer_id == htonl(UINT32_MAX)) { + return 0; } + + error = pktbuf_retrieve(ofconn->pktbuf, ntohl(ofm->buffer_id), + &packet, &in_port); + if (error) { + return error; + } + + flow_extract(packet, in_port, &flow); + rule_execute(ofproto, rule, packet, &flow); + ofpbuf_delete(packet); + return 0; } + +/* OFPFC_MODIFY and OFPFC_MODIFY_STRICT. */ struct modify_flows_cbdata { struct ofproto *ofproto; const struct ofp_flow_mod *ofm; - uint16_t out_port; size_t n_actions; - uint16_t command; + struct rule *match; }; +static int modify_flow(struct ofproto *, const struct ofp_flow_mod *, + size_t n_actions, struct rule *); +static void modify_flows_cb(struct cls_rule *, void *cbdata_); + +/* Implements OFPFC_MODIFY. Returns 0 on success or an OpenFlow error code as + * encoded by ofp_mkerr() on failure. + * + * 'ofconn' is used to retrieve the packet buffer specified in ofm->buffer_id, + * if any. */ +static int +modify_flows_loose(struct ofproto *p, struct ofconn *ofconn, + const struct ofp_flow_mod *ofm, size_t n_actions) +{ + struct modify_flows_cbdata cbdata; + struct cls_rule target; + + cbdata.ofproto = p; + cbdata.ofm = ofm; + cbdata.n_actions = n_actions; + cbdata.match = NULL; + + cls_rule_from_match(&target, &ofm->match, 0); + + classifier_for_each_match(&p->cls, &target, CLS_INC_ALL, + modify_flows_cb, &cbdata); + if (cbdata.match) { + /* This credits the packet to whichever flow happened to happened to + * match last. That's weird. Maybe we should do a lookup for the + * flow that actually matches the packet? Who knows. */ + send_buffered_packet(p, ofconn, cbdata.match, ofm); + return 0; + } else { + return add_flow(p, ofconn, ofm, n_actions); + } +} + +/* Implements OFPFC_MODIFY_STRICT. Returns 0 on success or an OpenFlow error + * code as encoded by ofp_mkerr() on failure. + * + * 'ofconn' is used to retrieve the packet buffer specified in ofm->buffer_id, + * if any. */ +static int +modify_flow_strict(struct ofproto *p, struct ofconn *ofconn, + struct ofp_flow_mod *ofm, size_t n_actions) +{ + struct rule *rule = find_flow_strict(p, ofm); + if (rule && !rule_is_hidden(rule)) { + modify_flow(p, ofm, n_actions, rule); + return send_buffered_packet(p, ofconn, rule, ofm); + } else { + return add_flow(p, ofconn, ofm, n_actions); + } +} + +/* Callback for modify_flows_loose(). */ static void modify_flows_cb(struct cls_rule *rule_, void *cbdata_) { struct rule *rule = rule_from_cls_rule(rule_); struct modify_flows_cbdata *cbdata = cbdata_; - if (cbdata->out_port != htons(OFPP_NONE) - && !rule_has_out_port(rule, cbdata->out_port)) { - return; + if (!rule_is_hidden(rule)) { + cbdata->match = rule; + modify_flow(cbdata->ofproto, cbdata->ofm, cbdata->n_actions, rule); } - - modify_flow(cbdata->ofproto, cbdata->ofm, cbdata->n_actions, - cbdata->command, rule); } +/* Implements core of OFPFC_MODIFY and OFPFC_MODIFY_STRICT where 'rule' has + * been identified as a flow in 'p''s flow table to be modified, by changing + * the rule's actions to match those in 'ofm' (which is followed by 'n_actions' + * ofp_action[] structures). */ static int -modify_flows_loose(struct ofproto *p, const struct ofp_flow_mod *ofm, - size_t n_actions, uint16_t command) +modify_flow(struct ofproto *p, const struct ofp_flow_mod *ofm, + size_t n_actions, struct rule *rule) { - struct modify_flows_cbdata cbdata; + size_t actions_len = n_actions * sizeof *rule->actions; + + rule->flow_cookie = ofm->cookie; + + /* If the actions are the same, do nothing. */ + if (n_actions == rule->n_actions + && !memcmp(ofm->actions, rule->actions, actions_len)) + { + return 0; + } + + /* Replace actions. */ + free(rule->actions); + rule->actions = xmemdup(ofm->actions, actions_len); + rule->n_actions = n_actions; + + /* Make sure that the datapath gets updated properly. */ + if (rule->cr.wc.wildcards) { + COVERAGE_INC(ofproto_mod_wc_flow); + p->need_revalidate = true; + } else { + rule_update_actions(p, rule); + } + + return 0; +} + +/* OFPFC_DELETE implementation. */ + +struct delete_flows_cbdata { + struct ofproto *ofproto; + uint16_t out_port; +}; + +static void delete_flows_cb(struct cls_rule *, void *cbdata_); +static void delete_flow(struct ofproto *, struct rule *, uint16_t out_port); + +/* Implements OFPFC_DELETE. */ +static void +delete_flows_loose(struct ofproto *p, const struct ofp_flow_mod *ofm) +{ + struct delete_flows_cbdata cbdata; struct cls_rule target; cbdata.ofproto = p; - cbdata.ofm = ofm; - cbdata.out_port = (command == OFPFC_DELETE ? ofm->out_port - : htons(OFPP_NONE)); - cbdata.n_actions = n_actions; - cbdata.command = command; + cbdata.out_port = ofm->out_port; cls_rule_from_match(&target, &ofm->match, 0); classifier_for_each_match(&p->cls, &target, CLS_INC_ALL, - modify_flows_cb, &cbdata); - return 0; + delete_flows_cb, &cbdata); +} + +/* Implements OFPFC_DELETE_STRICT. */ +static void +delete_flow_strict(struct ofproto *p, struct ofp_flow_mod *ofm) +{ + struct rule *rule = find_flow_strict(p, ofm); + if (rule) { + delete_flow(p, rule, ofm->out_port); + } +} + +/* Callback for delete_flows_loose(). */ +static void +delete_flows_cb(struct cls_rule *rule_, void *cbdata_) +{ + struct rule *rule = rule_from_cls_rule(rule_); + struct delete_flows_cbdata *cbdata = cbdata_; + + delete_flow(cbdata->ofproto, rule, cbdata->out_port); } +/* Implements core of OFPFC_DELETE and OFPFC_DELETE_STRICT where 'rule' has + * been identified as a flow to delete from 'p''s flow table, by deleting the + * flow and sending out a OFPT_FLOW_REMOVED message to any interested + * controller. + * + * Will not delete 'rule' if it is hidden. Will delete 'rule' only if + * 'out_port' is htons(OFPP_NONE) or if 'rule' actually outputs to the + * specified 'out_port'. */ +static void +delete_flow(struct ofproto *p, struct rule *rule, uint16_t out_port) +{ + if (rule_is_hidden(rule)) { + return; + } + + if (out_port != htons(OFPP_NONE) && !rule_has_out_port(rule, out_port)) { + return; + } + + send_flow_removed(p, rule, time_msec(), OFPRR_DELETE); + rule_remove(p, rule); +} + static int handle_flow_mod(struct ofproto *p, struct ofconn *ofconn, struct ofp_flow_mod *ofm) @@ -3057,16 +3181,18 @@ handle_flow_mod(struct ofproto *p, struct ofconn *ofconn, return add_flow(p, ofconn, ofm, n_actions); case OFPFC_MODIFY: - return modify_flows_loose(p, ofm, n_actions, OFPFC_MODIFY); + return modify_flows_loose(p, ofconn, ofm, n_actions); case OFPFC_MODIFY_STRICT: - return modify_flows_strict(p, ofm, n_actions, OFPFC_MODIFY); + return modify_flow_strict(p, ofconn, ofm, n_actions); case OFPFC_DELETE: - return modify_flows_loose(p, ofm, n_actions, OFPFC_DELETE); + delete_flows_loose(p, ofm); + return 0; case OFPFC_DELETE_STRICT: - return modify_flows_strict(p, ofm, n_actions, OFPFC_DELETE); + delete_flow_strict(p, ofm); + return 0; default: return ofp_mkerr(OFPET_FLOW_MOD_FAILED, OFPFMFC_BAD_COMMAND); -- 2.43.0