From 5bf0e941d91cc1236b0fa9551a75a287ca31282f Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Tue, 26 Apr 2011 11:30:46 -0700 Subject: [PATCH] ofproto: Better document the ofproto_class interface. Also, make a few minor adjustments to the interface so that it makes a little more sense. --- ofproto/ofproto-dpif.c | 15 +++- ofproto/ofproto.c | 21 +++-- ofproto/private.h | 190 ++++++++++++++++++++++++++++++++++++++--- 3 files changed, 203 insertions(+), 23 deletions(-) diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c index 53d7ca43..b1980b67 100644 --- a/ofproto/ofproto-dpif.c +++ b/ofproto/ofproto-dpif.c @@ -2450,6 +2450,13 @@ rule_construct(struct rule *rule_) struct rule_dpif *rule = rule_dpif_cast(rule_); struct ofproto_dpif *ofproto = ofproto_dpif_cast(rule->up.ofproto); struct cls_rule *displaced_rule; + int error; + + error = validate_actions(rule->up.actions, rule->up.n_actions, + &rule->up.cr.flow, ofproto->max_ports); + if (error) { + return error; + } rule->used = rule->up.created; rule->packet_count = 0; @@ -2508,7 +2515,7 @@ rule_get_stats(struct rule *rule_, uint64_t *packets, uint64_t *bytes) } } -static void +static int rule_execute(struct rule *rule_, struct flow *flow, struct ofpbuf *packet) { struct rule_dpif *rule = rule_dpif_cast(rule_); @@ -2522,7 +2529,7 @@ rule_execute(struct rule *rule_, struct flow *flow, struct ofpbuf *packet) facet = facet_lookup_valid(ofproto, flow); if (facet && facet->rule == rule) { facet_execute(ofproto, facet, packet); - return; + return 0; } /* Otherwise, if 'rule' is in fact the correct rule for 'packet', then @@ -2531,7 +2538,7 @@ rule_execute(struct rule *rule_, struct flow *flow, struct ofpbuf *packet) facet = facet_create(rule, flow, packet); facet_execute(ofproto, facet, packet); facet_install(ofproto, facet, true); - return; + return 0; } /* We can't account anything to a facet. If we were to try, then that @@ -2547,6 +2554,8 @@ rule_execute(struct rule *rule_, struct flow *flow, struct ofpbuf *packet) flow_push_stats(rule, flow, 1, size, rule->used); } ofpbuf_delete(odp_actions); + + return 0; } static int diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c index 8ec5a124..cead7f76 100644 --- a/ofproto/ofproto.c +++ b/ofproto/ofproto.c @@ -701,8 +701,10 @@ ofproto_run(struct ofproto *p) return ENODEV; } - while ((error = p->ofproto_class->port_poll(p, &devname)) != EAGAIN) { - process_port_change(p, error, devname); + if (p->ofproto_class->port_poll) { + while ((error = p->ofproto_class->port_poll(p, &devname)) != EAGAIN) { + process_port_change(p, error, devname); + } } while ((error = netdev_monitor_poll(p->netdev_monitor, &devname)) != EAGAIN) { @@ -718,7 +720,9 @@ void ofproto_wait(struct ofproto *p) { p->ofproto_class->wait(p); - p->ofproto_class->port_poll_wait(p); + if (p->ofproto_class->port_poll_wait) { + p->ofproto_class->port_poll_wait(p); + } netdev_monitor_poll_wait(p->netdev_monitor); connmgr_wait(p->connmgr); } @@ -1344,7 +1348,7 @@ ofproto_rule_lookup(struct ofproto *ofproto, const struct flow *flow) * with statistics for 'packet' either way. * * Takes ownership of 'packet'. */ -static void +static int rule_execute(struct rule *rule, uint16_t in_port, struct ofpbuf *packet) { struct flow flow; @@ -1352,7 +1356,7 @@ rule_execute(struct rule *rule, uint16_t in_port, struct ofpbuf *packet) assert(ofpbuf_headroom(packet) >= sizeof(struct ofp_packet_in)); flow_extract(packet, 0, in_port, &flow); - rule->ofproto->ofproto_class->rule_execute(rule, &flow, packet); + return rule->ofproto->ofproto_class->rule_execute(rule, &flow, packet); } /* Remove 'rule' from 'ofproto' and free up the associated memory: @@ -2212,7 +2216,8 @@ add_flow(struct ofconn *ofconn, struct flow_mod *fm) } if (packet) { - rule_execute(rule, in_port, packet); + assert(!buf_err); + return rule_execute(rule, in_port, packet); } return buf_err; } @@ -2240,9 +2245,7 @@ send_buffered_packet(struct ofconn *ofconn, return error; } - rule_execute(rule, in_port, packet); - - return 0; + return rule_execute(rule, in_port, packet); } /* OFPFC_MODIFY and OFPFC_MODIFY_STRICT. */ diff --git a/ofproto/private.h b/ofproto/private.h index cadd19e8..bf054fd5 100644 --- a/ofproto/private.h +++ b/ofproto/private.h @@ -204,8 +204,30 @@ struct ofproto_class { /* ## Factory Functions ## */ /* ## ----------------- ## */ + /* Enumerates the types of all support ofproto types into 'types'. The + * caller has already initialized 'types' and other ofproto classes might + * already have added names to it. */ void (*enumerate_types)(struct sset *types); + + /* Enumerates the names of all existing datapath of the specified 'type' + * into 'names' 'all_dps'. The caller has already initialized 'names' as + * an empty sset. + * + * 'type' is one of the types enumerated by ->enumerate_types(). + * + * Returns 0 if successful, otherwise a positive errno value. + */ int (*enumerate_names)(const char *type, struct sset *names); + + /* Deletes the datapath with the specified 'type' and 'name'. The caller + * should have closed any open ofproto with this 'type' and 'name'; this + * function is allowed to fail if that is not the case. + * + * 'type' is one of the types enumerated by ->enumerate_types(). + * 'name' is one of the names enumerated by ->enumerate_names() for 'type'. + * + * Returns 0 if successful, otherwise a positive errno value. + */ int (*del)(const char *type, const char *name); /* ## --------------------------- ## */ @@ -224,7 +246,10 @@ struct ofproto_class { * Only one ofproto instance needs to be supported for any given datapath. * If a datapath is already open as part of one "ofproto", then another * attempt to "construct" the same datapath as part of another ofproto is - * allowed to fail with an error. */ + * allowed to fail with an error. + * + * ->construct() returns 0 if successful, otherwise a positive errno + * value. */ struct ofproto *(*alloc)(void); int (*construct)(struct ofproto *ofproto); void (*destruct)(struct ofproto *ofproto); @@ -238,6 +263,10 @@ struct ofproto_class { * * - Call ofproto_rule_expire() for each OpenFlow flow that has reached * its hard_timeout or idle_timeout, to expire the flow. + * + * Returns 0 if successful, otherwise a positive errno value. The ENODEV + * return value specifically means that the datapath underlying 'ofproto' + * has been destroyed (externally, e.g. by an admin running ovs-dpctl). */ int (*run)(struct ofproto *ofproto); @@ -284,6 +313,9 @@ struct ofproto_class { * implementation's ports, in the same way as at ofproto * initialization, and construct and destruct ofports to reflect all of * the changes. + * + * ->port_construct() returns 0 if successful, otherwise a positive errno + * value. */ struct ofport *(*port_alloc)(void); int (*port_construct)(struct ofport *ofport); @@ -316,12 +348,22 @@ struct ofproto_class { int (*port_query_by_name)(const struct ofproto *ofproto, const char *devname, struct ofproto_port *port); - /* Attempts to add 'netdev' as a port on 'ofproto'. If successful, sets - * '*ofp_portp' to the new port's port number. */ + /* Attempts to add 'netdev' as a port on 'ofproto'. Returns 0 if + * successful, otherwise a positive errno value. If successful, sets + * '*ofp_portp' to the new port's port number. + * + * It doesn't matter whether the new port will be returned by a later call + * to ->port_poll(); the implementation may do whatever is more + * convenient. */ int (*port_add)(struct ofproto *ofproto, struct netdev *netdev, uint16_t *ofp_portp); - /* Deletes port number 'ofp_port' from the datapath for 'ofproto'. */ + /* Deletes port number 'ofp_port' from the datapath for 'ofproto'. Returns + * 0 if successful, otherwise a positive errno value. + * + * It doesn't matter whether the new port will be returned by a later call + * to ->port_poll(); the implementation may do whatever is more + * convenient. */ int (*port_del)(struct ofproto *ofproto, uint16_t ofp_port); /* Attempts to begin dumping the ports in 'ofproto'. On success, returns 0 @@ -371,39 +413,165 @@ struct ofproto_class { * * If the set of ports in 'ofproto' has not changed, returns EAGAIN. May * also return other positive errno values to indicate that something has - * gone wrong. */ + * gone wrong. + * + * If the set of ports in a datapath is fixed, or if the only way that the + * set of ports in a datapath can change is through ->port_add() and + * ->port_del(), then this function may be a null pointer. + */ int (*port_poll)(const struct ofproto *ofproto, char **devnamep); - /* Arranges for the poll loop to wake up when 'port_poll' will return a - * value other than EAGAIN. */ + /* Arranges for the poll loop to wake up when ->port_poll() will return a + * value other than EAGAIN. + * + * If the set of ports in a datapath is fixed, or if the only way that the + * set of ports in a datapath can change is through ->port_add() and + * ->port_del(), or if the poll loop will always wake up anyway when + * ->port_poll() will return a value other than EAGAIN, then this function + * may be a null pointer. + */ void (*port_poll_wait)(const struct ofproto *ofproto); + /* Checks the status of LACP negotiation for 'port'. Returns 1 if LACP + * partner information for 'port' is up-to-date, 0 if LACP partner + * information is not current (generally indicating a connectivity + * problem), or -1 if LACP is not enabled on 'port'. + * + * This function may be a null pointer if the ofproto implementation does + * not support LACP. */ int (*port_is_lacp_current)(const struct ofport *port); +/* ## ----------------------- ## */ +/* ## OpenFlow Rule Functions ## */ +/* ## ----------------------- ## */ + + /* Life-cycle functions for a "struct rule" (see "Life Cycle" above). + * + * ->rule_construct() should first check whether the rule is acceptable: + * + * - Validate that the matching rule in 'rule->cr' is supported by the + * datapath. If not, then return an OpenFlow error code (as returned + * by ofp_mkerr()). + * + * For example, if the datapath does not support registers, then it + * should return an error if 'rule->cr' does not wildcard all + * registers. + * + * - Validate that 'rule->actions' and 'rule->n_actions' are well-formed + * OpenFlow actions that can be correctly implemented by the datapath. + * If not, then return an OpenFlow error code (as returned by + * ofp_mkerr()). + * + * The validate_actions() function (in ofp-util.c) can be useful as a + * model for action validation, but it accepts all of the OpenFlow + * actions that OVS understands. If your ofproto implementation only + * implements a subset of those, then you should implement your own + * action validation. + * + * If the rule is acceptable, then ->rule_construct() should modify the + * flow table: + * + * - If there was already a rule with exactly the same matching criteria + * and priority in the classifier, then it should remove that rule from + * the classifier and destroy it (with ofproto_rule_destroy()). + * + * - Insert the new rule into the ofproto's 'cls' classifier, and into + * the datapath flow table. + * + * (The function classifier_insert() both inserts a rule into the + * classifier and removes any rule with identical matching criteria, so + * this single call implements parts of both steps above.) + * + * Other than inserting 'rule->cr' into the classifier, ->rule_construct() + * should not modify any base members of struct rule. + * + * When ->rule_destruct() is called, 'rule' has already been removed from + * the classifier and the datapath flow table (by calling ->rule_remove()), + * so ->rule_destruct() should not duplicate that behavior. */ struct rule *(*rule_alloc)(void); int (*rule_construct)(struct rule *rule); void (*rule_destruct)(struct rule *rule); void (*rule_dealloc)(struct rule *rule); + /* Removes 'rule' from 'rule->ofproto->cls' and from the datapath. + * + * 'rule' will be destructed, with ->rule_destruct(), soon after. */ void (*rule_remove)(struct rule *rule); + /* Obtains statistics for 'rule', storing the number of packets that have + * matched it in '*packet_count' and the number of bytes in those packets + * in '*byte_count'. */ void (*rule_get_stats)(struct rule *rule, uint64_t *packet_count, uint64_t *byte_count); - void (*rule_execute)(struct rule *rule, struct flow *flow, - struct ofpbuf *packet); - + /* Applies the actions in 'rule' to 'packet'. (This implements sending + * buffered packets for OpenFlow OFPT_FLOW_MOD commands.) + * + * Takes ownership of 'packet' (so it should eventually free it, with + * ofpbuf_delete()). + * + * 'flow' reflects the flow information for 'packet'. All of the + * information in 'flow' is extracted from 'packet', except for + * flow->tun_id and flow->in_port, which are assigned the correct values + * for the incoming packet. The register values are zeroed. + * + * The statistics for 'packet' should be included in 'rule'. + * + * Returns 0 if successful, otherwise an OpenFlow error code (as returned + * by ofp_mkerr()). */ + int (*rule_execute)(struct rule *rule, struct flow *flow, + struct ofpbuf *packet); + + /* Validates that the 'n' elements in 'actions' are well-formed OpenFlow + * actions that can be correctly implemented by the datapath. If not, then + * return an OpenFlow error code (as returned by ofp_mkerr()). If so, + * then update the datapath to implement the new actions and return 0. + * + * When this function runs, 'rule' still has its original actions. If this + * function returns 0, then the caller will update 'rule' with the new + * actions and free the old ones. */ int (*rule_modify_actions)(struct rule *rule, const union ofp_action *actions, size_t n); + /* These functions implement the OpenFlow IP fragment handling policy. By + * default ('drop_frags' == false), an OpenFlow switch should treat IP + * fragments the same way as other packets (although TCP and UDP port + * numbers cannot be determined). With 'drop_frags' == true, the switch + * should drop all IP fragments without passing them through the flow + * table. */ bool (*get_drop_frags)(struct ofproto *ofproto); void (*set_drop_frags)(struct ofproto *ofproto, bool drop_frags); + /* Implements the OpenFlow OFPT_PACKET_OUT command. The datapath should + * execute the 'n_actions' in the 'actions' array on 'packet'. + * + * The caller retains ownership of 'packet', so ->packet_out() should not + * modify or free it. + * + * This function must validate that the 'n_actions' elements in 'actions' + * are well-formed OpenFlow actions that can be correctly implemented by + * the datapath. If not, then it should return an OpenFlow error code (as + * returned by ofp_mkerr()). + * + * 'flow' reflects the flow information for 'packet'. All of the + * information in 'flow' is extracted from 'packet', except for + * flow->in_port, which is taken from the OFPT_PACKET_OUT message. + * flow->tun_id and its register values are zeroed. + * + * 'packet' is not matched against the OpenFlow flow table, so its + * statistics should not be included in OpenFlow flow statistics. + * + * Returns 0 if successful, otherwise an OpenFlow error code (as returned + * by ofp_mkerr()). */ int (*packet_out)(struct ofproto *ofproto, struct ofpbuf *packet, const struct flow *flow, const union ofp_action *actions, size_t n_actions); - + +/* ## ------------------------- ## */ +/* ## OFPP_NORMAL configuration ## */ +/* ## ------------------------- ## */ + /* Configures NetFlow on 'ofproto' according to the options in * 'netflow_options', or turns off NetFlow if 'netflow_options' is NULL. * -- 2.30.2