[ovs-dev] [next2 1/7] ofproto: Better document the ofproto_class interface.
Ethan Jackson
ethan at nicira.com
Wed May 11 18:27:51 UTC 2011
This patch seems fine to me.
I would think that documentation of the functions unchanged in this
patch would probably be better placed in the previous patch where
their prototypes are added. Not a big deal though.
Ethan
On Tue, Apr 26, 2011 at 13:51, Ben Pfaff <blp at nicira.com> wrote:
> 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 d83ed6a..4b34ff9 100644
> --- a/ofproto/ofproto-dpif.c
> +++ b/ofproto/ofproto-dpif.c
> @@ -2443,6 +2443,13 @@ 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;
> @@ -2500,7 +2507,7 @@ 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_);
> @@ -2514,7 +2521,7 @@ 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
> @@ -2523,7 +2530,7 @@ 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
> @@ -2539,6 +2546,8 @@ 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 0e76666..a22efe3 100644
> --- a/ofproto/ofproto.c
> +++ b/ofproto/ofproto.c
> @@ -695,8 +695,10 @@ 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) {
> @@ -712,7 +714,9 @@ 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);
> }
> @@ -1336,7 +1340,7 @@ 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;
> @@ -1344,7 +1348,7 @@ 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:
> @@ -2205,7 +2209,8 @@ 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;
> }
> @@ -2233,9 +2238,7 @@ 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 d79ed81..cbf2c2e 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.
> *
> --
> 1.7.4.4
>
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