[ovs-dev] [PATCH 15/26] ofproto-dpif-xlate: Clean up sFlow and IPFIX sampling code.
Ben Pfaff
blp at nicira.com
Thu Jul 30 06:42:35 UTC 2015
This code was a twisty maze of tiny functions, but what it actually needed
to do was simple. This makes it look that simple.
Among more stylistic changes, this removes 'user_cookie_offset' from
xlate_ctx. This member was used to communicate between two sections of
code that are both in xlate_actions() and close together, so it's better to
simply use a local variable than to put it into a shared context structure.
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
ofproto/ofproto-dpif-xlate.c | 255 ++++++++++++++++---------------------------
1 file changed, 97 insertions(+), 158 deletions(-)
diff --git a/ofproto/ofproto-dpif-xlate.c b/ofproto/ofproto-dpif-xlate.c
index 03bca1b..7726a40 100644
--- a/ofproto/ofproto-dpif-xlate.c
+++ b/ofproto/ofproto-dpif-xlate.c
@@ -205,7 +205,6 @@ struct xlate_ctx {
uint32_t orig_skb_priority; /* Priority when packet arrived. */
uint32_t sflow_n_outputs; /* Number of output ports. */
odp_port_t sflow_odp_port; /* Output port for composing sFlow action. */
- uint16_t user_cookie_offset;/* Used for user_action_cookie fixup. */
bool exit; /* No further actions should be processed. */
/* These are used for non-bond recirculation. The recirculation IDs are
@@ -2440,211 +2439,147 @@ xlate_normal(struct xlate_ctx *ctx)
}
}
-/* Compose SAMPLE action for sFlow or IPFIX. The given probability is
- * the number of packets out of UINT32_MAX to sample. The given
- * cookie is passed back in the callback for each sampled packet.
+/* Appends a "sample" action for sFlow or IPFIX to 'ctx->odp_actions'. The
+ * 'probability' is the number of packets out of UINT32_MAX to sample. The
+ * 'cookie' (of length 'cookie_size' bytes) is passed back in the callback for
+ * each sampled packet. 'tunnel_out_port', if not ODPP_NONE, is added as the
+ * OVS_USERSPACE_ATTR_EGRESS_TUN_PORT attribute. If 'include_actions', an
+ * OVS_USERSPACE_ATTR_ACTIONS attribute is added.
*/
static size_t
-compose_sample_action(const struct xbridge *xbridge,
- struct ofpbuf *odp_actions,
- const struct flow *flow,
+compose_sample_action(struct xlate_ctx *ctx,
const uint32_t probability,
const union user_action_cookie *cookie,
const size_t cookie_size,
const odp_port_t tunnel_out_port,
bool include_actions)
{
- size_t sample_offset, actions_offset;
- odp_port_t odp_port;
- int cookie_offset;
- uint32_t pid;
+ size_t sample_offset = nl_msg_start_nested(ctx->odp_actions,
+ OVS_ACTION_ATTR_SAMPLE);
- sample_offset = nl_msg_start_nested(odp_actions, OVS_ACTION_ATTR_SAMPLE);
+ nl_msg_put_u32(ctx->odp_actions, OVS_SAMPLE_ATTR_PROBABILITY, probability);
- nl_msg_put_u32(odp_actions, OVS_SAMPLE_ATTR_PROBABILITY, probability);
+ size_t actions_offset = nl_msg_start_nested(ctx->odp_actions,
+ OVS_SAMPLE_ATTR_ACTIONS);
- actions_offset = nl_msg_start_nested(odp_actions, OVS_SAMPLE_ATTR_ACTIONS);
+ odp_port_t odp_port = ofp_port_to_odp_port(
+ ctx->xbridge, ctx->xin->flow.in_port.ofp_port);
+ uint32_t pid = dpif_port_get_pid(ctx->xbridge->dpif, odp_port,
+ flow_hash_5tuple(&ctx->xin->flow, 0));
+ int cookie_offset = odp_put_userspace_action(pid, cookie, cookie_size,
+ tunnel_out_port,
+ include_actions,
+ ctx->odp_actions);
- odp_port = ofp_port_to_odp_port(xbridge, flow->in_port.ofp_port);
- pid = dpif_port_get_pid(xbridge->dpif, odp_port,
- flow_hash_5tuple(flow, 0));
- cookie_offset = odp_put_userspace_action(pid, cookie, cookie_size,
- tunnel_out_port,
- include_actions,
- odp_actions);
+ nl_msg_end_nested(ctx->odp_actions, actions_offset);
+ nl_msg_end_nested(ctx->odp_actions, sample_offset);
- nl_msg_end_nested(odp_actions, actions_offset);
- nl_msg_end_nested(odp_actions, sample_offset);
return cookie_offset;
}
-static void
-compose_sflow_cookie(const struct xbridge *xbridge, ovs_be16 vlan_tci,
- odp_port_t odp_port, unsigned int n_outputs,
- union user_action_cookie *cookie)
-{
- int ifindex;
-
- cookie->type = USER_ACTION_COOKIE_SFLOW;
- cookie->sflow.vlan_tci = vlan_tci;
-
- /* See http://www.sflow.org/sflow_version_5.txt (search for "Input/output
- * port information") for the interpretation of cookie->output. */
- switch (n_outputs) {
- case 0:
- /* 0x40000000 | 256 means "packet dropped for unknown reason". */
- cookie->sflow.output = 0x40000000 | 256;
- break;
-
- case 1:
- ifindex = dpif_sflow_odp_port_to_ifindex(xbridge->sflow, odp_port);
- if (ifindex) {
- cookie->sflow.output = ifindex;
- break;
- }
- /* Fall through. */
- default:
- /* 0x80000000 means "multiple output ports. */
- cookie->sflow.output = 0x80000000 | n_outputs;
- break;
- }
-}
-
-/* Compose SAMPLE action for sFlow bridge sampling. */
+/* If sFLow is not enabled, returns 0 without doing anything.
+ *
+ * If sFlow is enabled, appends a template "sample" action to the ODP actions
+ * in 'ctx'. This action is a template because some of the information needed
+ * to fill it out is not available until flow translation is complete. In this
+ * case, this functions returns an offset, which is always nonzero, to pass
+ * later to fix_sflow_action() to fill in the rest of the template. */
static size_t
-compose_sflow_action(const struct xbridge *xbridge,
- struct ofpbuf *odp_actions,
- const struct flow *flow,
- odp_port_t odp_port)
+compose_sflow_action(struct xlate_ctx *ctx)
{
- uint32_t probability;
- union user_action_cookie cookie;
-
- if (!xbridge->sflow || flow->in_port.ofp_port == OFPP_NONE) {
+ struct dpif_sflow *sflow = ctx->xbridge->sflow;
+ if (!sflow || ctx->xin->flow.in_port.ofp_port == OFPP_NONE) {
return 0;
}
- probability = dpif_sflow_get_probability(xbridge->sflow);
- compose_sflow_cookie(xbridge, htons(0), odp_port,
- odp_port == ODPP_NONE ? 0 : 1, &cookie);
-
- return compose_sample_action(xbridge, odp_actions, flow, probability,
+ union user_action_cookie cookie = { .type = USER_ACTION_COOKIE_SFLOW };
+ return compose_sample_action(ctx, dpif_sflow_get_probability(sflow),
&cookie, sizeof cookie.sflow, ODPP_NONE,
true);
}
+/* If IPFIX is enabled, this appends a "sample" action to implement IPFIX to
+ * 'ctx->odp_actions'. */
static void
-compose_flow_sample_cookie(uint16_t probability, uint32_t collector_set_id,
- uint32_t obs_domain_id, uint32_t obs_point_id,
- union user_action_cookie *cookie)
-{
- cookie->type = USER_ACTION_COOKIE_FLOW_SAMPLE;
- cookie->flow_sample.probability = probability;
- cookie->flow_sample.collector_set_id = collector_set_id;
- cookie->flow_sample.obs_domain_id = obs_domain_id;
- cookie->flow_sample.obs_point_id = obs_point_id;
-}
-
-static void
-compose_ipfix_cookie(union user_action_cookie *cookie,
- odp_port_t output_odp_port)
-{
- cookie->type = USER_ACTION_COOKIE_IPFIX;
- cookie->ipfix.output_odp_port = output_odp_port;
-}
-
-/* Compose SAMPLE action for IPFIX bridge sampling. */
-static void
-compose_ipfix_action(const struct xbridge *xbridge,
- struct ofpbuf *odp_actions,
- const struct flow *flow,
- odp_port_t output_odp_port)
+compose_ipfix_action(struct xlate_ctx *ctx, odp_port_t output_odp_port)
{
- uint32_t probability;
- union user_action_cookie cookie;
+ struct dpif_ipfix *ipfix = ctx->xbridge->ipfix;
odp_port_t tunnel_out_port = ODPP_NONE;
- if (!xbridge->ipfix || flow->in_port.ofp_port == OFPP_NONE) {
+ if (!ipfix || ctx->xin->flow.in_port.ofp_port == OFPP_NONE) {
return;
}
/* For input case, output_odp_port is ODPP_NONE, which is an invalid port
* number. */
if (output_odp_port == ODPP_NONE &&
- !dpif_ipfix_get_bridge_exporter_input_sampling(xbridge->ipfix)) {
+ !dpif_ipfix_get_bridge_exporter_input_sampling(ipfix)) {
return;
}
/* For output case, output_odp_port is valid*/
if (output_odp_port != ODPP_NONE) {
- if (!dpif_ipfix_get_bridge_exporter_output_sampling(xbridge->ipfix)) {
+ if (!dpif_ipfix_get_bridge_exporter_output_sampling(ipfix)) {
return;
}
/* If tunnel sampling is enabled, put an additional option attribute:
* OVS_USERSPACE_ATTR_TUNNEL_OUT_PORT
*/
- if (dpif_ipfix_get_bridge_exporter_tunnel_sampling(xbridge->ipfix) &&
- dpif_ipfix_get_tunnel_port(xbridge->ipfix, output_odp_port) ) {
+ if (dpif_ipfix_get_bridge_exporter_tunnel_sampling(ipfix) &&
+ dpif_ipfix_get_tunnel_port(ipfix, output_odp_port) ) {
tunnel_out_port = output_odp_port;
}
}
- probability = dpif_ipfix_get_bridge_exporter_probability(xbridge->ipfix);
- compose_ipfix_cookie(&cookie, output_odp_port);
-
- compose_sample_action(xbridge, odp_actions, flow, probability,
+ union user_action_cookie cookie = {
+ .ipfix = {
+ .type = USER_ACTION_COOKIE_IPFIX,
+ .output_odp_port = output_odp_port,
+ }
+ };
+ compose_sample_action(ctx,
+ dpif_ipfix_get_bridge_exporter_probability(ipfix),
&cookie, sizeof cookie.ipfix, tunnel_out_port,
false);
}
-/* SAMPLE action for sFlow must be first action in any given list of
- * actions. At this point we do not have all information required to
- * build it. So try to build sample action as complete as possible. */
-static void
-add_sflow_action(struct xlate_ctx *ctx)
-{
- ctx->user_cookie_offset = compose_sflow_action(ctx->xbridge,
- ctx->odp_actions,
- &ctx->xin->flow, ODPP_NONE);
- ctx->sflow_odp_port = 0;
- ctx->sflow_n_outputs = 0;
-}
-
-/* SAMPLE action for IPFIX must be 1st or 2nd action in any given list
- * of actions, eventually after the SAMPLE action for sFlow. */
-static void
-add_ipfix_action(struct xlate_ctx *ctx)
-{
- compose_ipfix_action(ctx->xbridge, ctx->odp_actions,
- &ctx->xin->flow, ODPP_NONE);
-}
-
-static void
-add_ipfix_output_action(struct xlate_ctx *ctx, odp_port_t port)
-{
- compose_ipfix_action(ctx->xbridge, ctx->odp_actions,
- &ctx->xin->flow, port);
-}
-
-/* Fix SAMPLE action according to data collected while composing ODP actions.
- * We need to fix SAMPLE actions OVS_SAMPLE_ATTR_ACTIONS attribute, i.e. nested
- * USERSPACE action's user-cookie which is required for sflow. */
+/* Fix "sample" action according to data collected while composing ODP actions,
+ * as described in compose_sflow_action().
+ *
+ * 'user_cookie_offset' must be the offset returned by add_sflow_action(). */
static void
-fix_sflow_action(struct xlate_ctx *ctx)
+fix_sflow_action(struct xlate_ctx *ctx, unsigned int user_cookie_offset)
{
const struct flow *base = &ctx->base_flow;
union user_action_cookie *cookie;
- if (!ctx->user_cookie_offset) {
- return;
- }
-
- cookie = ofpbuf_at(ctx->odp_actions, ctx->user_cookie_offset,
+ cookie = ofpbuf_at(ctx->odp_actions, user_cookie_offset,
sizeof cookie->sflow);
ovs_assert(cookie->type == USER_ACTION_COOKIE_SFLOW);
- compose_sflow_cookie(ctx->xbridge, base->vlan_tci,
- ctx->sflow_odp_port, ctx->sflow_n_outputs, cookie);
+ cookie->type = USER_ACTION_COOKIE_SFLOW;
+ cookie->sflow.vlan_tci = base->vlan_tci;
+
+ /* See http://www.sflow.org/sflow_version_5.txt (search for "Input/output
+ * port information") for the interpretation of cookie->output. */
+ switch (ctx->sflow_n_outputs) {
+ case 0:
+ /* 0x40000000 | 256 means "packet dropped for unknown reason". */
+ cookie->sflow.output = 0x40000000 | 256;
+ break;
+
+ case 1:
+ cookie->sflow.output = dpif_sflow_odp_port_to_ifindex(
+ ctx->xbridge->sflow, ctx->sflow_odp_port);
+ if (cookie->sflow.output) {
+ break;
+ }
+ /* Fall through. */
+ default:
+ /* 0x80000000 means "multiple output ports. */
+ cookie->sflow.output = 0x80000000 | ctx->sflow_n_outputs;
+ break;
+ }
}
static bool
@@ -3096,7 +3031,7 @@ compose_output_action__(struct xlate_ctx *ctx, ofp_port_t ofp_port,
} else {
/* Tunnel push-pop action is not compatible with
* IPFIX action. */
- add_ipfix_output_action(ctx, out_port);
+ compose_ipfix_action(ctx, out_port);
nl_msg_put_odp_port(ctx->odp_actions,
OVS_ACTION_ATTR_OUTPUT,
out_port);
@@ -3955,7 +3890,6 @@ static void
xlate_sample_action(struct xlate_ctx *ctx,
const struct ofpact_sample *os)
{
- union user_action_cookie cookie;
/* Scale the probability from 16-bit to 32-bit while representing
* the same percentage. */
uint32_t probability = (os->probability << 16) | os->probability;
@@ -3975,12 +3909,17 @@ xlate_sample_action(struct xlate_ctx *ctx,
ctx->odp_actions,
ctx->wc, use_masked);
- compose_flow_sample_cookie(os->probability, os->collector_set_id,
- os->obs_domain_id, os->obs_point_id, &cookie);
- compose_sample_action(ctx->xbridge, ctx->odp_actions,
- &ctx->xin->flow, probability, &cookie,
- sizeof cookie.flow_sample, ODPP_NONE,
- false);
+ union user_action_cookie cookie = {
+ .flow_sample = {
+ .type = USER_ACTION_COOKIE_FLOW_SAMPLE,
+ .probability = os->probability,
+ .collector_set_id = os->collector_set_id,
+ .obs_domain_id = os->obs_domain_id,
+ .obs_point_id = os->obs_point_id,
+ }
+ };
+ compose_sample_action(ctx, probability, &cookie, sizeof cookie.flow_sample,
+ ODPP_NONE, false);
}
static bool
@@ -4821,7 +4760,6 @@ xlate_actions(struct xlate_in *xin, struct xlate_out *xout)
.orig_skb_priority = flow->skb_priority,
.sflow_n_outputs = 0,
.sflow_odp_port = 0,
- .user_cookie_offset = 0,
.exit = false,
.recirc_action_offset = -1,
@@ -4996,9 +4934,10 @@ xlate_actions(struct xlate_in *xin, struct xlate_out *xout)
}
/* Sampling is done only for packets really received by the bridge. */
+ unsigned int user_cookie_offset = 0;
if (!xin->recirc) {
- add_sflow_action(&ctx);
- add_ipfix_action(&ctx);
+ user_cookie_offset = compose_sflow_action(&ctx);
+ compose_ipfix_action(&ctx, ODPP_NONE);
}
size_t sample_actions_len = ctx.odp_actions->size;
@@ -5056,8 +4995,8 @@ xlate_actions(struct xlate_in *xin, struct xlate_out *xout)
compose_output_action(&ctx, OFPP_LOCAL, NULL);
}
- if (!xin->recirc) {
- fix_sflow_action(&ctx);
+ if (user_cookie_offset) {
+ fix_sflow_action(&ctx, user_cookie_offset);
}
/* Only mirror fully processed packets. */
if (!exit_recirculates(&ctx)
--
2.1.3
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