bool exit; /* No further actions should be processed. */
mirror_mask_t mirrors; /* Bitmap of associated mirrors. */
- /* These are used for non-bond recirculation. The recirculation IDs are
- * stored in xout and must be associated with a datapath flow (ukey),
- * otherwise they will be freed when the xout is uninitialized.
+ /* Freezing Translation
+ * ====================
*
+ * At some point during translation, the code may recognize the need to halt
+ * and checkpoint the translation in a way that it can be restarted again
+ * later. We call the checkpointing process "freezing" and the restarting
+ * process "thawing".
*
- * Steps in Recirculation Translation
- * ==================================
+ * The use cases for freezing are:
*
- * At some point during translation, the code recognizes the need for
- * recirculation. For example, recirculation is necessary when, after
- * popping the last MPLS label, an action or a match tries to examine or
- * modify a field that has been newly revealed following the MPLS label.
+ * - "Recirculation", where the translation process discovers that it
+ * doesn't have enough information to complete translation without
+ * actually executing the actions that have already been translated,
+ * which provides the additionally needed information. In these
+ * situations, translation freezes translation and assigns the frozen
+ * data a unique "recirculation ID", which it associates with the data
+ * in a table in userspace (see ofproto-dpif-rid.h). It also adds a
+ * OVS_ACTION_ATTR_RECIRC action specifying that ID to the datapath
+ * actions. When a packet hits that action, the datapath looks its
+ * flow up again using the ID. If there's a miss, it comes back to
+ * userspace, which find the recirculation table entry for the ID,
+ * thaws the associated frozen data, and continues translation from
+ * that point given the additional information that is now known.
*
- * The simplest part of the work to be done is to commit existing changes to
- * the packet, which produces datapath actions corresponding to the changes,
- * and after this, add an OVS_ACTION_ATTR_RECIRC datapath action.
+ * The archetypal example is MPLS. As MPLS is implemented in
+ * OpenFlow, the protocol that follows the last MPLS label becomes
+ * known only when that label is popped by an OpenFlow action. That
+ * means that Open vSwitch can't extract the headers beyond the MPLS
+ * labels until the pop action is executed. Thus, at that point
+ * translation uses the recirculation process to extract the headers
+ * beyond the MPLS labels.
*
- * The main problem here is preserving state. When the datapath executes
- * OVS_ACTION_ATTR_RECIRC, it will upcall to userspace to get a translation
- * for the post-recirculation actions. At this point userspace has to
- * resume the translation where it left off, which means that it has to
- * execute the following:
+ * (OVS also uses OVS_ACTION_ATTR_RECIRC to implement hashing for
+ * output to bonds. OVS pre-populates all the datapath flows for bond
+ * output in the datapath, though, which means that the elaborate
+ * process of coming back to userspace for a second round of
+ * translation isn't needed, and so bonds don't follow the above
+ * process.)
*
- * - The action that prompted recirculation, and any actions following
- * it within the same flow.
*
- * - If the action that prompted recirculation was invoked within a
- * NXAST_RESUBMIT, then any actions following the resubmit. These
- * "resubmit"s can be nested, so this has to go all the way up the
- * control stack.
+ * The main problem of freezing translation is preserving state, so that
+ * when the translation is thawed later it resumes from where it left off,
+ * without disruption. In particular, actions must be preserved as follows:
+ *
+ * - If we're freezing because an action needed more information, the
+ * action that prompted it.
+ *
+ * - Any actions remaining to be translated within the current flow.
+ *
+ * - If translation was frozen within a NXAST_RESUBMIT, then any actions
+ * following the resubmit action. Resubmit actions can be nested, so
+ * this has to go all the way up the control stack.
*
* - The OpenFlow 1.1+ action set.
*
*
* - Metadata fields (input port, registers, OF1.1+ metadata, ...).
*
- * - Action set, stack
+ * - The stack used by NXAST_STACK_PUSH and NXAST_STACK_POP actions.
*
* - The table ID and cookie of the flow being translated at each level
- * of the control stack (since OFPAT_CONTROLLER actions send these to
- * the controller).
+ * of the control stack, because these can become visible through
+ * OFPAT_CONTROLLER actions (and other ways).
*
* Translation allows for the control of this state preservation via these
- * members. When a need for recirculation is identified, the translation
- * process:
+ * members. When a need to freeze translation is identified, the
+ * translation process:
*
- * 1. Sets 'recirculating' to true.
+ * 1. Sets 'freezing' to true.
*
* 2. Sets 'exit' to true to tell later steps that we're exiting from the
* translation process.
*
- * 3. Adds an OFPACT_UNROLL_XLATE action to 'recirculate_actions', and
- * points recirculate_actions.header to the action to make it easy to
- * find it later. This action holds the current table ID and cookie so
- * that they can be restored during a post-recirculation upcall
- * translation.
+ * 3. Adds an OFPACT_UNROLL_XLATE action to 'frozen_actions', and points
+ * frozen_actions.header to the action to make it easy to find it later.
+ * This action holds the current table ID and cookie so that they can be
+ * restored during a post-recirculation upcall translation.
*
* 4. Adds the action that prompted recirculation and any actions following
- * it within the same flow to 'recirculate_actions', so that they can be
+ * it within the same flow to 'frozen_actions', so that they can be
* executed during a post-recirculation upcall translation.
*
* 5. Returns.
*
* 6. The action that prompted recirculation might be nested in a stack of
* nested "resubmit"s that have actions remaining. Each of these notices
- * that we're exiting and recirculating and responds by adding more
- * OFPACT_UNROLL_XLATE actions to 'recirculate_actions', as necessary,
- * and any actions that were yet unprocessed.
+ * that we're exiting and freezing and responds by adding more
+ * OFPACT_UNROLL_XLATE actions to 'frozen_actions', as necessary,
+ * followed by any actions that were yet unprocessed.
*
- * The caller stores all the state produced by this process associated with
- * the recirculation ID. For post-recirculation upcall translation, the
- * caller passes it back in for the new translation to execute. The
- * process yielded a set of ofpacts that can be translated directly, so it
- * is not much of a special case at that point.
+ * If we're freezing because of recirculation, the caller generates a
+ * recirculation ID and associates all the state produced by this process
+ * with it. For post-recirculation upcall translation, the caller passes it
+ * back in for the new translation to execute. The process yielded a set of
+ * ofpacts that can be translated directly, so it is not much of a special
+ * case at that point.
*/
- bool recirculating;
- struct ofpbuf recirculate_actions;
+ bool freezing;
+ struct ofpbuf frozen_actions;
/* True if a packet was but is no longer MPLS (due to an MPLS pop action).
* This is a trigger for recirculation in cases where translating an action
/* True if conntrack has been performed on this packet during processing
* on the current bridge. This is used to determine whether conntrack
- * state from the datapath should be honored after recirculation. */
+ * state from the datapath should be honored after thawing. */
bool conntracked;
/* Pointer to an embedded NAT action in a conntrack action, or NULL. */
static void xlate_commit_actions(struct xlate_ctx *ctx);
static void
-ctx_trigger_recirculation(struct xlate_ctx *ctx)
+ctx_trigger_freeze(struct xlate_ctx *ctx)
{
ctx->exit = true;
- ctx->recirculating = true;
+ ctx->freezing = true;
}
static bool
-ctx_first_recirculation_action(const struct xlate_ctx *ctx)
+ctx_first_frozen_action(const struct xlate_ctx *ctx)
{
- return !ctx->recirculate_actions.size;
+ return !ctx->frozen_actions.size;
}
static void
-ctx_cancel_recirculation(struct xlate_ctx *ctx)
+ctx_cancel_freeze(struct xlate_ctx *ctx)
{
- if (ctx->recirculating) {
- ctx->recirculating = false;
- ofpbuf_clear(&ctx->recirculate_actions);
- ctx->recirculate_actions.header = NULL;
+ if (ctx->freezing) {
+ ctx->freezing = false;
+ ofpbuf_clear(&ctx->frozen_actions);
+ ctx->frozen_actions.header = NULL;
}
}
if (!process_special(ctx, peer) && may_receive(peer, ctx)) {
if (xport_stp_forward_state(peer) && xport_rstp_forward_state(peer)) {
xlate_table_action(ctx, flow->in_port.ofp_port, 0, true, true);
- if (!ctx->recirculating) {
+ if (!ctx->freezing) {
xlate_action_set(ctx);
}
- if (ctx->recirculating) {
+ if (ctx->freezing) {
compose_recirculate_action(ctx);
}
} else {
ctx->base_flow = old_base_flow;
ctx->odp_actions->size = old_size;
- /* Undo changes that may have been done for recirculation. */
- ctx_cancel_recirculation(ctx);
+ /* Undo changes that may have been done for freezing. */
+ ctx_cancel_freeze(ctx);
}
}
/* The fact that the peer bridge exits (for any reason) does not mean
* that the original bridge should exit. Specifically, if the peer
- * bridge recirculates (which typically modifies the packet), the
- * original bridge must continue processing with the original, not the
- * recirculated packet! */
+ * bridge freezes translation, the original bridge must continue
+ * processing with the original, not the frozen packet! */
ctx->exit = false;
/* Peer bridge errors do not propagate back. */
{
/* Check if we need to recirculate before matching in a table. */
if (ctx->was_mpls) {
- ctx_trigger_recirculation(ctx);
+ ctx_trigger_freeze(ctx);
return;
}
if (xlate_resubmit_resource_check(ctx)) {
ofpbuf_uninit(&action_list);
/* Check if need to recirculate. */
- if (ctx->recirculating) {
+ if (ctx->freezing) {
compose_recirculate_action(ctx);
}
/* The fact that the group bucket exits (for any reason) does not mean that
* the translation after the group action should exit. Specifically, if
- * the group bucket recirculates (which typically modifies the packet), the
- * actions after the group action must continue processing with the
- * original, not the recirculated packet! */
+ * the group bucket freezes translation, the actions after the group action
+ * must continue processing with the original, not the frozen packet! */
ctx->exit = false;
}
static void
compose_recirculate_action__(struct xlate_ctx *ctx, uint8_t table)
{
- struct recirc_metadata md;
+ struct frozen_metadata md;
uint32_t id;
- recirc_metadata_from_flow(&md, &ctx->xin->flow);
+ frozen_metadata_from_flow(&md, &ctx->xin->flow);
- ovs_assert(ctx->recirculating);
+ ovs_assert(ctx->freezing);
- struct recirc_state state = {
+ struct frozen_state state = {
.table_id = table,
.ofproto_uuid = *ofproto_dpif_get_uuid(ctx->xbridge->ofproto),
.metadata = md,
.n_stack = ctx->stack.size / sizeof(union mf_subvalue),
.mirrors = ctx->mirrors,
.conntracked = ctx->conntracked,
- .ofpacts = ctx->recirculate_actions.data,
- .ofpacts_len = ctx->recirculate_actions.size,
+ .ofpacts = ctx->frozen_actions.data,
+ .ofpacts_len = ctx->frozen_actions.size,
.action_set = ctx->action_set.data,
.action_set_len = ctx->action_set.size,
};
nl_msg_put_u32(ctx->odp_actions, OVS_ACTION_ATTR_RECIRC, id);
- /* Undo changes done by recirculation. */
- ctx_cancel_recirculation(ctx);
+ /* Undo changes done by freezing. */
+ ctx_cancel_freeze(ctx);
}
-/* Called only when we're recirculating. */
+/* Called only when we're freezing. */
static void
compose_recirculate_action(struct xlate_ctx *ctx)
{
static void
compose_recirculate_and_fork(struct xlate_ctx *ctx, uint8_t table)
{
- ctx->recirculating = true;
+ ctx->freezing = true;
compose_recirculate_action__(ctx, table);
}
}
static void
-recirc_put_unroll_xlate(struct xlate_ctx *ctx)
+freeze_put_unroll_xlate(struct xlate_ctx *ctx)
{
- struct ofpact_unroll_xlate *unroll = ctx->recirculate_actions.header;
+ struct ofpact_unroll_xlate *unroll = ctx->frozen_actions.header;
/* Restore the table_id and rule cookie for a potential PACKET
* IN if needed. */
if (!unroll ||
(ctx->table_id != unroll->rule_table_id
|| ctx->rule_cookie != unroll->rule_cookie)) {
- unroll = ofpact_put_UNROLL_XLATE(&ctx->recirculate_actions);
+ unroll = ofpact_put_UNROLL_XLATE(&ctx->frozen_actions);
unroll->rule_table_id = ctx->table_id;
unroll->rule_cookie = ctx->rule_cookie;
- ctx->recirculate_actions.header = unroll;
+ ctx->frozen_actions.header = unroll;
}
}
-/* Copy actions 'a' through 'end' to ctx->recirculate_actions, which will be
- * executed after recirculation. UNROLL_XLATE action is inserted, if not
- * already done so, before actions that may depend on the current table ID or
- * flow cookie. */
+/* Copy actions 'a' through 'end' to ctx->frozen_actions, which will be
+ * executed after thawing. Inserts an UNROLL_XLATE action, if none is already
+ * present, before any action that may depend on the current table ID or flow
+ * cookie. */
static void
-recirc_unroll_actions(const struct ofpact *a, const struct ofpact *end,
+freeze_unroll_actions(const struct ofpact *a, const struct ofpact *end,
struct xlate_ctx *ctx)
{
for (; a < end; a = ofpact_next(a)) {
case OFPACT_DEC_TTL:
/* These actions may generate asynchronous messages, which include
* table ID and flow cookie information. */
- recirc_put_unroll_xlate(ctx);
+ freeze_put_unroll_xlate(ctx);
break;
case OFPACT_RESUBMIT:
if (ofpact_get_RESUBMIT(a)->table_id == 0xff) {
/* This resubmit action is relative to the current table, so we
* need to track what table that is.*/
- recirc_put_unroll_xlate(ctx);
+ freeze_put_unroll_xlate(ctx);
}
break;
continue;
}
/* Copy the action over. */
- ofpbuf_put(&ctx->recirculate_actions, a, OFPACT_ALIGN(a->len));
+ ofpbuf_put(&ctx->frozen_actions, a, OFPACT_ALIGN(a->len));
}
}
#define CHECK_MPLS_RECIRCULATION() \
if (ctx->was_mpls) { \
- ctx_trigger_recirculation(ctx); \
+ ctx_trigger_freeze(ctx); \
break; \
}
#define CHECK_MPLS_RECIRCULATION_IF(COND) \
if (ctx->exit) {
/* Check if need to store the remaining actions for later
* execution. */
- if (ctx->recirculating) {
- recirc_unroll_actions(a, ofpact_end(ofpacts, ofpacts_len),
+ if (ctx->freezing) {
+ freeze_unroll_actions(a, ofpact_end(ofpacts, ofpacts_len),
ctx);
}
break;
break;
case OFPACT_RESUBMIT:
- /* Recirculation complicates resubmit. There are two cases:
+ /* Freezing complicates resubmit. There are two cases:
*
* - If mpls_pop has been executed, then the flow table lookup
* as part of resubmit might depend on fields that can only
* the post-recirculation actions.
*
* - Otherwise, some action in the flow entry found by resubmit
- * might trigger recirculation. If that happens, then we do
- * not want to execute the resubmit again after
- * recirculation, so we want to skip back to the head of the
- * loop to avoid that, only adding any actions that follow
- * the resubmit to the post-recirculation actions.
+ * might trigger freezing. If that happens, then we do not
+ * want to execute the resubmit again during thawing, so we
+ * want to skip back to the head of the loop to avoid that,
+ * only adding any actions that follow the resubmit to the
+ * frozen actions.
*/
if (ctx->was_mpls) {
- ctx_trigger_recirculation(ctx);
+ ctx_trigger_freeze(ctx);
break;
}
xlate_ofpact_resubmit(ctx, ofpact_get_RESUBMIT(a));
break;
case OFPACT_DEBUG_RECIRC:
- ctx_trigger_recirculation(ctx);
+ ctx_trigger_freeze(ctx);
a = ofpact_next(a);
break;
}
/* Check if need to store this and the remaining actions for later
* execution. */
- if (!ctx->error && ctx->exit && ctx_first_recirculation_action(ctx)) {
- recirc_unroll_actions(a, ofpact_end(ofpacts, ofpacts_len), ctx);
+ if (!ctx->error && ctx->exit && ctx_first_frozen_action(ctx)) {
+ freeze_unroll_actions(a, ofpact_end(ofpacts, ofpacts_len), ctx);
break;
}
}
xin->odp_actions = odp_actions;
/* Do recirc lookup. */
- xin->recirc = NULL;
+ xin->frozen_state = NULL;
if (flow->recirc_id) {
const struct recirc_id_node *node
= recirc_id_node_find(flow->recirc_id);
if (node) {
- xin->recirc = &node->state;
+ xin->frozen_state = &node->state;
}
}
}
union mf_subvalue stack_stub[1024 / sizeof(union mf_subvalue)];
uint64_t action_set_stub[1024 / 8];
- uint64_t recirculate_actions_stub[1024 / 8];
+ uint64_t frozen_actions_stub[1024 / 8];
struct flow_wildcards scratch_wc;
uint64_t actions_stub[256 / 8];
struct ofpbuf scratch_actions = OFPBUF_STUB_INITIALIZER(actions_stub);
.error = XLATE_OK,
.mirrors = 0,
- .recirculating = false,
- .recirculate_actions = OFPBUF_STUB_INITIALIZER(recirculate_actions_stub),
+ .freezing = false,
+ .frozen_actions = OFPBUF_STUB_INITIALIZER(frozen_actions_stub),
.was_mpls = false,
.conntracked = false,
COVERAGE_INC(xlate_actions);
- if (xin->recirc) {
- const struct recirc_state *state = xin->recirc;
+ if (xin->frozen_state) {
+ const struct frozen_state *state = xin->frozen_state;
- xlate_report(&ctx, "Restoring state post-recirculation:");
+ xlate_report(&ctx, "Thawing frozen state:");
if (xin->ofpacts_len > 0 || ctx.rule) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
if (OVS_UNLIKELY(!new_bridge)) {
/* Drop the packet if the bridge cannot be found. */
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
- VLOG_WARN_RL(&rl, "Recirculation bridge no longer exists.");
- xlate_report(&ctx, "- Recirculation bridge no longer exists.");
+ VLOG_WARN_RL(&rl, "Frozen bridge no longer exists.");
+ xlate_report(&ctx, "- Frozen bridge no longer exists.");
ctx.error = XLATE_BRIDGE_NOT_FOUND;
goto exit;
}
ctx.xbridge = new_bridge;
}
- /* Set the post-recirculation table id. Note: A table lookup is done
- * only if there are no post-recirculation actions. */
+ /* Set the thawed table id. Note: A table lookup is done only if there
+ * are no frozen actions. */
ctx.table_id = state->table_id;
xlate_report(&ctx, "- Resuming from table %"PRIu8, ctx.table_id);
}
/* Restore pipeline metadata. May change flow's in_port and other
- * metadata to the values that existed when recirculation was
- * triggered. */
- recirc_metadata_to_flow(&state->metadata, flow);
+ * metadata to the values that existed when freezing was triggered. */
+ frozen_metadata_to_flow(&state->metadata, flow);
/* Restore stack, if any. */
if (state->stack) {
state->action_set_len);
}
- /* Restore recirculation actions. If there are no actions, processing
- * will start with a lookup in the table set above. */
+ /* Restore frozen actions. If there are no actions, processing will
+ * start with a lookup in the table set above. */
xin->ofpacts = state->ofpacts;
xin->ofpacts_len = state->ofpacts_len;
if (state->ofpacts_len) {
}
}
- /* Get the proximate input port of the packet. (If xin->recirc,
+ /* Get the proximate input port of the packet. (If xin->frozen_state,
* flow->in_port is the ultimate input port of the packet.) */
struct xport *in_port = get_ofp_port(xbridge,
ctx.base_flow.in_port.ofp_port);
- /* Tunnel stats only for non-recirculated packets. */
- if (!xin->recirc && in_port && in_port->is_tunnel) {
+ /* Tunnel stats only for not-thawed packets. */
+ if (!xin->frozen_state && in_port && in_port->is_tunnel) {
if (ctx.xin->resubmit_stats) {
netdev_vport_inc_rx(in_port->netdev, ctx.xin->resubmit_stats);
if (in_port->bfd) {
}
}
- if (!xin->recirc && process_special(&ctx, in_port)) {
+ if (!xin->frozen_state && process_special(&ctx, in_port)) {
/* process_special() did all the processing for this packet.
*
- * We do not perform special processing on recirculated packets, as
- * recirculated packets are not really received by the bridge.*/
+ * We do not perform special processing on thawed packets, since that
+ * was done before they were frozen and should not be redone. */
} else if (in_port && in_port->xbundle
&& xbundle_mirror_out(xbridge, in_port->xbundle)) {
if (ctx.xin->packet != NULL) {
ctx.xbridge->name, in_port->xbundle->name);
}
} else {
- /* Sampling is done only for packets really received by the bridge. */
+ /* Sampling is done on initial reception; don't redo after thawing. */
unsigned int user_cookie_offset = 0;
- if (!xin->recirc) {
+ if (!xin->frozen_state) {
user_cookie_offset = compose_sflow_action(&ctx);
compose_ipfix_action(&ctx, ODPP_NONE);
}
}
/* We've let OFPP_NORMAL and the learning action look at the
- * packet, so cancel all actions and recirculation if forwarding is
+ * packet, so cancel all actions and freezing if forwarding is
* disabled. */
if (in_port && (!xport_stp_forward_state(in_port) ||
!xport_rstp_forward_state(in_port))) {
ctx.odp_actions->size = sample_actions_len;
- ctx_cancel_recirculation(&ctx);
+ ctx_cancel_freeze(&ctx);
ofpbuf_clear(&ctx.action_set);
}
- if (!ctx.recirculating) {
+ if (!ctx.freezing) {
xlate_action_set(&ctx);
}
- if (ctx.recirculating) {
+ if (ctx.freezing) {
compose_recirculate_action(&ctx);
}
}
/* Output only fully processed packets. */
- if (!ctx.recirculating
+ if (!ctx.freezing
&& xbridge->has_in_band
&& in_band_must_output_to_local_port(flow)
&& !actions_output_to_local_port(&ctx)) {
ctx.xout->slow |= SLOW_ACTION;
}
- /* Do netflow only for packets really received by the bridge and not sent
- * to the controller. We consider packets sent to the controller to be
- * part of the control plane rather than the data plane. */
- if (!xin->recirc && xbridge->netflow && !(xout->slow & SLOW_CONTROLLER)) {
+ /* Do netflow only for packets on initial reception, that are not sent to
+ * the controller. We consider packets sent to the controller to be part
+ * of the control plane rather than the data plane. */
+ if (!xin->frozen_state
+ && xbridge->netflow
+ && !(xout->slow & SLOW_CONTROLLER)) {
if (ctx.xin->resubmit_stats) {
netflow_flow_update(xbridge->netflow, flow,
ctx.nf_output_iface,
exit:
ofpbuf_uninit(&ctx.stack);
ofpbuf_uninit(&ctx.action_set);
- ofpbuf_uninit(&ctx.recirculate_actions);
+ ofpbuf_uninit(&ctx.frozen_actions);
ofpbuf_uninit(&scratch_actions);
/* Make sure we return a "drop flow" in case of an error. */
projects / cascardo / ovs.git / commitdiff