On Fri, Jul 31, 2015 at 02:25:22PM -0700, Jarno Rajahalme wrote:
> I’m starting to dig the designated initializers, too :-)
My favorite use of them is the following example C99 standard. I
haven't actually used this style myself yet, though:
EXAMPLE 3 Initializers with designations can be combined with compound
literals. Structure objects created using compound literals can be
passed to functions without depending on member order:
drawline((struct point){.x=1, .y=1},
(struct point){.x=3, .y=4});
Or, if drawline instead expected pointers to struct point:
drawline(&(struct point){.x=1, .y=1},
&(struct point){.x=3, .y=4});
> Acked-by: Jarno Rajahalme <jrajaha...@nicira.com>
Thanks!
> > On Jul 29, 2015, at 11:42 PM, Ben Pfaff <b...@nicira.com> wrote:
> >
> > 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 <b...@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
> >
> > _______________________________________________
> > dev mailing list
> > dev@openvswitch.org
> > http://openvswitch.org/mailman/listinfo/dev
>
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