On Tue, Oct 24, 2023 at 9:36 PM Han Zhou <[email protected]> wrote:
> Enhance MAC_Binding aging to allow CIDR-based threshold configurations.
> This enables distinct threshold settings for different IP ranges,
> applying the longest prefix matching for overlapping ranges.
>
> A common use case involves setting a default threshold for all IPs, while
> disabling aging for a specific range and potentially excluding a subset
> within that range.
>
> Signed-off-by: Han Zhou <[email protected]>
> ---
>
Hi Han,
thank you for the patch, I have a couple of comments down below.
> northd/aging.c | 297 +++++++++++++++++++++++++++++++++++++++++++++---
> northd/aging.h | 3 +
> northd/northd.c | 11 +-
> ovn-nb.xml | 63 +++++++++-
> tests/ovn.at | 60 ++++++++++
> 5 files changed, 413 insertions(+), 21 deletions(-)
>
> diff --git a/northd/aging.c b/northd/aging.c
> index f626c72c8ca3..e5868211a63b 100644
> --- a/northd/aging.c
> +++ b/northd/aging.c
> @@ -47,12 +47,253 @@ aging_waker_schedule_next_wake(struct aging_waker
> *waker, int64_t next_wake_ms)
> }
> }
>
> +struct threshold_entry {
> + union {
> + ovs_be32 ipv4;
> + struct in6_addr ipv6;
> + } prefix;
> + bool is_v4;
>
We can avoid the is_v4 whatsover by storing the address as mapped v4 in
'in6_addr', I saw the concern and we can still have separate arrays for v4
and v6. The parsing IMO becomes much simpler if we use the mapped v4 for
both see down below.
> + unsigned int plen;
> + unsigned int threshold;
>
I personally prefer sized integers.
> +};
> +
> +/* Contains CIDR-based aging threshold configuration parsed from
> + * "Logical_Router:options:mac_binding_age_threshold".
> + *
> + * This struct is also used for non-CIDR-based threshold, e.g. the ones
> from
> + * "NB_Global:other_config:fdb_age_threshold" for the common aging_context
> + * interface.
> + *
> + * - The arrays `v4_entries` and `v6_entries` are populated with parsed
> entries
> + * for IPv4 and IPv6 CIDRs, respectively, along with their associated
> + * thresholds. Entries within these arrays are sorted by prefix length,
> + * starting with the longest.
> + *
> + * - If a threshold is provided without an accompanying prefix, it's
> captured
> + * in `default_threshold`. In cases with multiple unprefixed
> thresholds,
> + * `default_threshold` will only store the last one. */
> +struct threshold_config {
> + struct threshold_entry *v4_entries;
> + int n_v4_entries;
> + struct threshold_entry *v6_entries;
> + int n_v6_entries;
> + unsigned int default_threshold;
> +};
> +
> +static int
> +compare_entries_by_prefix_length(const void *a, const void *b)
> +{
> + const struct threshold_entry *entry_a = a;
> + const struct threshold_entry *entry_b = b;
> +
> + return entry_b->plen - entry_a->plen;
> +}
> +
> +/* Parse an ENTRY in the threshold option, with the format:
> + * [CIDR:]THRESHOLD
> + *
> + * Returns true if successful, false if failed. */
> +static bool
> +parse_threshold_entry(const char *str, struct threshold_entry *entry)
> +{
> + char *colon_ptr;
> + unsigned int value;
> + const char *threshold_str;
> +
> + colon_ptr = strrchr(str, ':');
>
I find this a bit confusing and probably error prone, could we use
different delimiters for the threshold? I guess we could change it to
'cidr;threshold,cidr;threshold' WDYT? This would allow us to use
'strtok_r()' here and we could spare the multiple copies and replace with a
single one.
> + if (!colon_ptr) {
> + threshold_str = str;
> + entry->plen = 0;
> + } else {
> + threshold_str = colon_ptr + 1;
> + }
> +
> + if (!str_to_uint(threshold_str, 10, &value)) {
> + return false;
> + }
> + entry->threshold = value;
> +
> + if (!colon_ptr) {
> + return true;
> + }
> +
> + /* ":" was found, so parse the string before ":" as a cidr. */
> + char ip_cidr[128];
> + ovs_strzcpy(ip_cidr, str, MIN(colon_ptr - str + 1, sizeof ip_cidr));
> + char *error = ip_parse_cidr(ip_cidr, &entry->prefix.ipv4,
> &entry->plen);
>
As mentioned earlier by storing it in 'in6_addr' we could use
'ip46_parse_cidr()' which would simplify the logic. We can also adjust the
prefix for v4 so the search is the same for both.
> + if (!error) {
> + entry->is_v4 = true;
> + return true;
> + }
> + free(error);
> + error = ipv6_parse_cidr(ip_cidr, &entry->prefix.ipv6, &entry->plen);
> + if (!error) {
> + entry->is_v4 = false;
> + return true;
> + }
> + free(error);
> + return false;
> +}
> +
> +static void
> +threshold_config_destroy(struct threshold_config *config)
> +{
> + free(config->v4_entries);
> + free(config->v6_entries);
> + config->v4_entries = config->v6_entries = NULL;
> + config->n_v4_entries = config->n_v6_entries = 0;
> + config->default_threshold = 0;
> +}
> +
> +/* Parse the threshold option string, which has the format:
> + * ENTRY[;ENTRY[...]]
> + *
> + * For the exact format of ENTRY, refer to the function
> + * `parse_threshold_entry`.
> + *
> + * The parsed data is populated to the struct threshold_config.
> + * See the comments of struct threshold_config for details.
> + *
> + * Return Values:
> + * - Returns `false` if the input does not match the expected format.
> + * Consequently, no entries will be populated.
> + * - Returns `true` upon successful parsing. The caller is responsible for
> + * releasing the allocated memory by calling threshold_config_destroy.
> */
> +static bool
> +parse_aging_threshold(const char *opt,
> + struct threshold_config *config)
> +{
> + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
> + struct threshold_entry e;
> + const char *start = opt, *end;
> + memset(config, 0, sizeof *config);
> +
> + while (start && *start) {
> + end = strchr(start, ';');
>
We should use 'strtok_r()' this again allows us to avoid the constant
copies replaced by single one.
> + if (end) {
> + /* Big enough for any <ipv6>/<ipv6 mask>:<threshold> */
> + char buf[128];
> + ovs_strzcpy(buf, start, MIN(end - start + 1, sizeof buf));
> + if (!parse_threshold_entry(buf, &e)) {
> + VLOG_WARN_RL(&rl, "Parsing aging threshold '%s' failed.",
> buf);
> + goto err;
> + }
> + start = end + 1;
> + } else {
> + if (!parse_threshold_entry(start, &e)) {
> + VLOG_WARN_RL(&rl, "Parsing aging threshold '%s' failed.",
> + start);
> + goto err;
> + }
> + start += strlen(start);
> + }
> + if (!e.plen) {
> + config->default_threshold = e.threshold;
> + } else if (e.is_v4) {
> + config->n_v4_entries++;
> + config->v4_entries = xrealloc(config->v4_entries,
> + config->n_v4_entries * sizeof
> e);
> + config->v4_entries[config->n_v4_entries - 1] = e;
> + } else {
> + config->n_v6_entries++;
> + config->v6_entries = xrealloc(config->v6_entries,
> + config->n_v6_entries * sizeof
> e);
> + config->v6_entries[config->n_v6_entries - 1] = e;
> + }
> + }
> +
> + if (config->n_v4_entries > 0) {
> + qsort(config->v4_entries, config->n_v4_entries, sizeof e,
> + compare_entries_by_prefix_length);
> + }
> +
> + if (config->n_v6_entries > 0) {
> + qsort(config->v6_entries, config->n_v6_entries, sizeof e,
> + compare_entries_by_prefix_length);
> + }
> +
> + return true;
> +
> +err:
> + threshold_config_destroy(config);
> + return false;
> +}
> +
> +static unsigned int
> +find_threshold_for_ip(const char *ip_str,
> + const struct threshold_config *config)
> +{
> + if (!ip_str) {
> + return config->default_threshold;
> + }
> +
> + ovs_be32 ipv4;
> + struct in6_addr ipv6;
> + if (ip_parse(ip_str, &ipv4)) {
> + for (int i = 0; i < config->n_v4_entries; i++) {
> + ovs_be32 masked_ip = ipv4 &
> + be32_prefix_mask(config->v4_entries[i].plen);
> + if (masked_ip == config->v4_entries[i].prefix.ipv4) {
> + return config->v4_entries[i].threshold;
> + }
> + }
> + } else if (ipv6_parse(ip_str, &ipv6)) {
> + for (int i = 0; i < config->n_v6_entries; i++) {
> + struct in6_addr v6_mask =
> + ipv6_create_mask(config->v6_entries[i].plen);
> + struct in6_addr masked_ip = ipv6_addr_bitand(&ipv6, &v6_mask);
> + if (ipv6_addr_equals(&masked_ip,
> + &config->v6_entries[i].prefix.ipv6)) {
> + return config->v6_entries[i].threshold;
> + }
> + }
> + }
> + return config->default_threshold;
> +}
> +
> +/* Parse the threshold option string (see the comment of the function
> + * parse_aging_threshold), and returns the smallest threshold. */
> +unsigned int
> +min_mac_binding_age_threshold(const char *opt)
> +{
> + struct threshold_config config;
> + if (!parse_aging_threshold(opt, &config)) {
> + return 0;
> + }
> +
> + unsigned int threshold = UINT_MAX;
> + unsigned int t;
> +
> + for (int i = 0; i < config.n_v4_entries; i++) {
> + t = config.v4_entries[i].threshold;
> + if (t && t < threshold) {
> + threshold = t;
> + }
> + }
> +
> + for (int i = 0; i < config.n_v6_entries; i++) {
> + t = config.v6_entries[i].threshold;
> + if (t && t < threshold) {
> + threshold = t;
> + }
> + }
> +
> + t = config.default_threshold;
> + if (t && t < threshold) {
> + threshold = t;
> + }
> +
> + threshold_config_destroy(&config);
> +
> + return threshold == UINT_MAX ? 0 : threshold;
> +}
> +
> struct aging_context {
> int64_t next_wake_ms;
> int64_t time_wall_now;
> uint32_t removal_limit;
> uint32_t n_removed;
> - uint64_t threshold;
> + struct threshold_config *threshold;
> };
>
> static struct aging_context
> @@ -63,13 +304,14 @@ aging_context_init(uint32_t removal_limit)
> .time_wall_now = time_wall_msec(),
> .removal_limit = removal_limit,
> .n_removed = 0,
> - .threshold = 0,
> + .threshold = NULL,
> };
> return ctx;
> }
>
> static void
> -aging_context_set_threshold(struct aging_context *ctx, uint64_t threshold)
> +aging_context_set_threshold(struct aging_context *ctx,
> + struct threshold_config *threshold)
> {
> ctx->threshold = threshold;
> }
> @@ -81,19 +323,27 @@ aging_context_is_at_limit(struct aging_context *ctx)
> }
>
> static bool
> -aging_context_handle_timestamp(struct aging_context *ctx, int64_t
> timestamp)
> +aging_context_handle_timestamp(struct aging_context *ctx, int64_t
> timestamp,
> + const char *ip)
> {
> int64_t elapsed = ctx->time_wall_now - timestamp;
> if (elapsed < 0) {
> return false;
> }
>
> - if (elapsed >= ctx->threshold) {
> + ovs_assert(ctx->threshold);
> + uint64_t threshold = 1000 * find_threshold_for_ip(ip, ctx->threshold);
> +
> + if (!threshold) {
> + return false;
> + }
> +
> + if (elapsed >= threshold) {
> ctx->n_removed++;
> return true;
> }
>
> - ctx->next_wake_ms = MIN(ctx->next_wake_ms, (ctx->threshold -
> elapsed));
> + ctx->next_wake_ms = MIN(ctx->next_wake_ms, (threshold - elapsed));
> return false;
> }
>
> @@ -121,13 +371,18 @@ mac_binding_aging_run_for_datapath(const struct
> sbrec_datapath_binding *dp,
> return;
> }
>
> + if (!ctx->threshold->n_v4_entries && !ctx->threshold->n_v6_entries
> + && !ctx->threshold->default_threshold) {
> + return;
> + }
> +
> struct sbrec_mac_binding *mb_index_row =
> sbrec_mac_binding_index_init_row(mb_by_datapath);
> sbrec_mac_binding_index_set_datapath(mb_index_row, dp);
>
> const struct sbrec_mac_binding *mb;
> SBREC_MAC_BINDING_FOR_EACH_EQUAL (mb, mb_index_row, mb_by_datapath) {
> - if (aging_context_handle_timestamp(ctx, mb->timestamp)) {
> + if (aging_context_handle_timestamp(ctx, mb->timestamp, mb->ip)) {
> sbrec_mac_binding_delete(mb);
> if (aging_context_is_at_limit(ctx)) {
> break;
> @@ -166,13 +421,20 @@ en_mac_binding_aging_run(struct engine_node *node,
> void *data OVS_UNUSED)
> continue;
> }
>
> - uint64_t threshold = smap_get_uint(&od->nbr->options,
> - "mac_binding_age_threshold",
> 0);
> - aging_context_set_threshold(&ctx, threshold * 1000);
> + struct threshold_config threshold_config;
> + if (!parse_aging_threshold(smap_get(&od->nbr->options,
> + "mac_binding_age_threshold"),
> + &threshold_config)) {
> + return;
> + }
> +
> + aging_context_set_threshold(&ctx, &threshold_config);
>
> mac_binding_aging_run_for_datapath(od->sb,
> sbrec_mac_binding_by_datapath,
> &ctx);
> + threshold_config_destroy(&threshold_config);
> +
> if (aging_context_is_at_limit(&ctx)) {
> /* Schedule the next run after specified delay. */
> ctx.next_wake_ms = AGING_BULK_REMOVAL_DELAY_MSEC;
> @@ -255,7 +517,7 @@ fdb_run_for_datapath(const struct
> sbrec_datapath_binding *dp,
>
> const struct sbrec_fdb *fdb;
> SBREC_FDB_FOR_EACH_EQUAL (fdb, fdb_index_row, fdb_by_dp_key) {
> - if (aging_context_handle_timestamp(ctx, fdb->timestamp)) {
> + if (aging_context_handle_timestamp(ctx, fdb->timestamp, NULL)) {
> sbrec_fdb_delete(fdb);
> if (aging_context_is_at_limit(ctx)) {
> break;
> @@ -293,11 +555,16 @@ en_fdb_aging_run(struct engine_node *node, void
> *data OVS_UNUSED)
> continue;
> }
>
> - uint64_t threshold =
> - smap_get_uint(&od->nbs->other_config,
> "fdb_age_threshold", 0);
> - aging_context_set_threshold(&ctx, threshold * 1000);
> -
> + struct threshold_config threshold_config;
> + if (!parse_aging_threshold(smap_get(&od->nbs->other_config,
> + "fdb_age_threshold"),
> + &threshold_config)) {
>
This would mean that fdb aging would accept the same arguments, but that
doesn't seem right. We should set only the default value instead of the
whole parsing.
> + return;
> + }
> + aging_context_set_threshold(&ctx, &threshold_config);
> fdb_run_for_datapath(od->sb, sbrec_fdb_by_dp_key, &ctx);
> + threshold_config_destroy(&threshold_config);
> +
> if (aging_context_is_at_limit(&ctx)) {
> /* Schedule the next run after specified delay. */
> ctx.next_wake_ms = AGING_BULK_REMOVAL_DELAY_MSEC;
> diff --git a/northd/aging.h b/northd/aging.h
> index 650990e244aa..2cfe2fd44457 100644
> --- a/northd/aging.h
> +++ b/northd/aging.h
> @@ -30,6 +30,9 @@ void *en_mac_binding_aging_waker_init(struct engine_node
> *node,
> struct engine_arg *arg);
> void en_mac_binding_aging_waker_cleanup(void *data);
>
> +/* The MAC binding aging helper function. */
> +unsigned int min_mac_binding_age_threshold(const char *opt);
> +
> /* The FDB aging node functions. */
> void en_fdb_aging_run(struct engine_node *node, void *data);
> void *en_fdb_aging_init(struct engine_node *node, struct engine_arg *arg);
> diff --git a/northd/northd.c b/northd/northd.c
> index f8b046d83e85..4bc898982cf2 100644
> --- a/northd/northd.c
> +++ b/northd/northd.c
> @@ -17,6 +17,7 @@
> #include <stdlib.h>
> #include <stdio.h>
>
> +#include "aging.h"
> #include "debug.h"
> #include "bitmap.h"
> #include "coverage.h"
> @@ -1166,8 +1167,14 @@ ovn_datapath_update_external_ids(struct
> ovn_datapath *od)
> smap_add(&ids, "always_learn_from_arp_request", "false");
> }
>
> - uint32_t age_threshold = smap_get_uint(&od->nbr->options,
> -
> "mac_binding_age_threshold", 0);
> + /* For timestamp refreshing, the smallest threshold of the option
> is
> + * set to SB to make sure all entries are refreshed in time.
> + * XXX: This approach simplifies processing in ovn-controller,
> but it
> + * may be enhanced, if necessary, to parse the complete CIDR-based
> + * threshold configurations to SB to reduce unnecessary
> refreshes. */
> + uint32_t age_threshold = min_mac_binding_age_threshold(
> + smap_get(&od->nbr->options,
> +
> "mac_binding_age_threshold"));
> if (age_threshold) {
> smap_add_format(&ids, "mac_binding_age_threshold",
> "%u", age_threshold);
> diff --git a/ovn-nb.xml b/ovn-nb.xml
> index 1de0c30416ce..80733273484e 100644
> --- a/ovn-nb.xml
> +++ b/ovn-nb.xml
> @@ -2686,10 +2686,65 @@ or
> </column>
>
> <column name="options" key="mac_binding_age_threshold"
> - type='{"type": "integer", "minInteger": 0, "maxInteger":
> 4294967295}'>
> - MAC binding aging <code>threshold</code> value in seconds. MAC
> binding
> - exceeding this timeout will be automatically removed. The value
> - defaults to 0, which means disabled.
> + type='{"type": "string"}'>
> + <p>
> + Specifies the MAC binding aging thresholds based on CIDRs,
> with the
> + format: <var>entry</var>[<code>;</code><var>entry</var>[...]],
> + where each <var>entry</var> has the format:
> + [<var>cidr</var><code>:</code>]<var>threshold</var>
> + </p>
> +
> + <ul>
> + <li>
> + <var>cidr</var>: Can be either an IPv4 or IPv6 CIDR.
> + </li>
> + <li>
> + <var>threshold</var>: Threshold value in seconds. MAC
> bindings with
> + IP addresses matching the specified CIDR that exceed this
> timeout
> + will be automatically removed.
> + </li>
> + </ul>
> +
> + <p>
> + If an <var>entry</var> is provided without an CIDR (just the
> + threshold value), it specifies the default threshold for MAC
> + bindings that don't match any of the given CIDRs. If there are
> + multiple default threshold entries in the option, the
> behavior is
> + undefined.
> + </p>
> +
> + <p>
> + If there are multiple CIDRs matching a MAC binding IP, the
> one with
> + the longest prefix length takes effect. If there are multiple
> + entries with the same CIDR in the option, the behavior is
> + undefined.
> + </p>
> +
> + <p>
> + If no matching CIDR is found for a MAC binding IP, and no
> default
> + threshold is specified, the behavior defaults to the
> original: the
> + binding will not be removed based on age.
> + </p>
> +
> + <p>
> + The value can also default to an empty string, which means
> that the
> + aging threshold is disabled. Any string not in the above
> format is
> + regarded as invalid and the aging is disabled.
> + </p>
> +
> + <p>
> + Example:
> + <code>192.168.0.0/16:300;192.168.10.0/24:0;fe80::/10:600;1200
> </code>
> + </p>
> +
> + <p>
> + This sets a threshold of 300 seconds for MAC bindings with IP
> + addresses in the 192.168.0.0/16 range, excluding the
> 192.168.1.0/24
> + range (for which the aging is disabled), a threshold of 600
> seconds
> + for MAC bindings with IP addresses in the fe80::/10 IPv6
> range, and
> + a default threshold of 1200 seconds for all other MAC
> bindings.
> + </p>
> +
> </column>
> </group>
>
> diff --git a/tests/ovn.at b/tests/ovn.at
> index 637d92bedbc7..07b5c1ec57fc 100644
> --- a/tests/ovn.at
> +++ b/tests/ovn.at
> @@ -34676,6 +34676,66 @@ OVS_WAIT_UNTIL([
>
> AT_CHECK([as hv1 ovs-ofctl dump-flows br-int table=79 --no-stats |
> strip_cookie], [0], [])
>
> +# Test CIDR-based threshold configuration
> +check ovn-nbctl set logical_router gw options:mac_binding_age_threshold="
> 192.168.10.0/255.255.255.0:2;192.168.10.64/26:0;192.168.10.20:0"
> +check ovn-nbctl --wait=sb sync
> +uuid=$(fetch_column datapath _uuid external_ids:name=gw)
> +AT_CHECK([ovn-sbctl get datapath $uuid
> external_ids:mac_binding_age_threshold], [0], [dnl
> +"2"
> +])
> +
> +# Send GARP to populate MAC binding table records
> +send_garp hv1 ext1 10 # belong to 192.168.10.0/24
> +send_garp hv2 ext2 20 # belong to 192.168.10.20/32
> +send_garp hv2 ext2 65 # belong to 192.168.10.64/26
> +
> +OVS_WAIT_UNTIL([ovn-sbctl list mac_binding | grep -q "192.168.10.10"])
> +OVS_WAIT_UNTIL([ovn-sbctl list mac_binding | grep -q "192.168.10.20"])
> +OVS_WAIT_UNTIL([ovn-sbctl list mac_binding | grep -q "192.168.10.65"])
> +
> +OVS_WAIT_UNTIL([
> + test "0" = "$(ovn-sbctl list mac_binding | grep -c '192.168.10.10')"
> +])
> +# The other two should remain because the corresponding prefixes have
> threshold 0
> +AT_CHECK([ovn-sbctl list mac_binding | grep -q "192.168.10.20"])
> +AT_CHECK([ovn-sbctl list mac_binding | grep -q "192.168.10.65"])
> +check ovn-sbctl --all destroy mac_binding
> +
> +# Set the aging threshold mixed with IPv6 prefixes and default threshold
> +check ovn-nbctl set logical_router gw
> options:mac_binding_age_threshold="1;192.168.10.64/26:0;ff00:1234::/32:888
> "
> +check ovn-nbctl --wait=sb sync
> +uuid=$(fetch_column datapath _uuid external_ids:name=gw)
> +AT_CHECK([ovn-sbctl get datapath $uuid
> external_ids:mac_binding_age_threshold], [0], [dnl
> +"1"
> +])
> +
> +# Send GARP to populate MAC binding table records
> +send_garp hv1 ext1 10 # belong to default
> +send_garp hv2 ext2 65 # belong to 192.168.10.64/26
> +
> +OVS_WAIT_UNTIL([ovn-sbctl list mac_binding | grep -q "192.168.10.10"])
> +OVS_WAIT_UNTIL([ovn-sbctl list mac_binding | grep -q "192.168.10.65"])
> +
> +OVS_WAIT_UNTIL([
> + test "0" = "$(ovn-sbctl list mac_binding | grep -c '192.168.10.10')"
> +])
> +AT_CHECK([ovn-sbctl list mac_binding | grep -q "192.168.10.65"])
> +check ovn-sbctl --all destroy mac_binding
> +
> +# Set the aging threshold with invalid format
> +check ovn-nbctl set logical_router gw
> options:mac_binding_age_threshold="1;abc/26:0"
> +check ovn-nbctl --wait=sb sync
> +uuid=$(fetch_column datapath _uuid external_ids:name=gw)
> +AT_CHECK([ovn-sbctl get datapath $uuid
> external_ids:mac_binding_age_threshold], [1], [ignore], [ignore])
> +
> +# Send GARP to populate MAC binding table records
> +send_garp hv1 ext1 10
> +
> +OVS_WAIT_UNTIL([ovn-sbctl list mac_binding | grep -q "192.168.10.10"])
> +# The record is not deleted
> +sleep 5
> +AT_CHECK([ovn-sbctl list mac_binding | grep -q "192.168.10.10"])
> +
> OVN_CLEANUP([hv1], [hv2])
> AT_CLEANUP
> ])
> --
> 2.38.1
>
> _______________________________________________
> dev mailing list
> [email protected]
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>
>
Thanks,
Ales
--
Ales Musil
Senior Software Engineer - OVN Core
Red Hat EMEA <https://www.redhat.com>
[email protected]
<https://red.ht/sig>
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