base.c

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/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or (at
 *   your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 8e61208e2bf0767fe2acffd8a4e8861e4721c625 $
 * @file kafka/base.c
 * @brief Kafka global structures
 *
 * @copyright 2022 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
 
#include <freeradius-devel/kafka/base.h>
#include <freeradius-devel/server/tmpl.h>
#include <freeradius-devel/util/size.h>
 
/* fr_kafka_conf_ctx_t definition lives in base.h so the KAFKA_BASE_CONFIG
 * macro can construct struct literals of it from caller TUs. */
 
/** @name Shared helpers
 *
 * Used by both the base-level and topic-level parse/dflt paths below.
 *
 * @{
 */
 
/** Common parse path for a single CONF_PAIR's value
 *
 * Handles librdkafka's preferred unit conventions (ms-integer for time
 * deltas, byte-integer for sizes, string "true"/"false" for bools) and
 * the optional kctx->mapping translation.  Caller hands the resulting
 * string to either rd_kafka_conf_set or rd_kafka_topic_conf_set.
 */
static int kafka_config_parse_single(char const **out, CONF_PAIR *cp, conf_parser_t const *rule)
{
        fr_value_box_t                  vb = FR_VALUE_BOX_INITIALISER_NULL(vb);
        fr_kafka_conf_ctx_t const       *kctx = rule->uctx;
        fr_type_t                       type = rule->type;
        static _Thread_local char       buff[sizeof("18446744073709551615")];
        static _Thread_local fr_sbuff_t sbuff;
 
        /*
         *      Map string values if possible, and if there's
         *      no match then just pass the original through.
         *
         *      We count this as validation...
         */
        if (kctx->mapping) {
                fr_table_ptr_sorted_t   *mapping = kctx->mapping;
                size_t                  mapping_len = *kctx->mapping_len;
 
                *out = fr_table_value_by_str(mapping, cf_pair_value(cp), cf_pair_value(cp));
                return 0;
        } else if (fr_type_is_string(type)) {
                *out = cf_pair_value(cp);
                return 0;
        }
 
        /*
         *      Parse as a box for basic validation
         */
        if (cf_pair_to_value_box(NULL, &vb, cp, rule) < 0) return -1;
 
        /*
         *      In kafka all the time deltas are in ms
         *      resolution, so we need to take the parsed value,
         *      scale it, and print it back to a string.
         */
        switch (type) {
        case FR_TYPE_TIME_DELTA:
        {
                uint64_t                        delta;
 
                sbuff = FR_SBUFF_OUT(buff, sizeof(buff));
                delta = fr_time_delta_to_msec(vb.vb_time_delta);
                if (fr_sbuff_in_sprintf(&sbuff, "%" PRIu64, delta) < 0) {
                error:
                        fr_value_box_clear(&vb);
                        return -1;
                }
                *out = fr_sbuff_start(&sbuff);
        }
                break;
 
        case FR_TYPE_SIZE:
        {
                size_t size = vb.vb_size;
 
                sbuff = FR_SBUFF_OUT(buff, sizeof(buff));
 
                /*
                 *      Most options are in bytes, but some are in kilobytes
                 */
                if (kctx->size_scale) size /= kctx->size_scale;
 
                /*
                 *      Kafka doesn't want units...
                 */
                if (fr_sbuff_in_sprintf(&sbuff, "%zu", size) < 0) goto error;
                *out = fr_sbuff_start(&sbuff);
        }
                break;
 
        /*
         *      Ensure bool is always mapped to the string constants
         *      "true" or "false".
         */
        case FR_TYPE_BOOL:
                *out = vb.vb_bool ? "true" : "false";
                break;
 
        default:
                *out = cf_pair_value(cp);
                break;
        }
 
        fr_value_box_clear(&vb);
 
        return 0;
}
 
/** Common dflt path: take a librdkafka-native value string and materialise
 *  it as a CONF_PAIR in the caller's units (time deltas as "Ns", sizes
 *  with unit suffixes, etc.).  Invoked by the base and topic dflt funcs.
 *
 * @param[out] out      Where to write the pair.
 * @param[in] parent    being populated.
 * @param[in] cs        to allocate the pair in.
 * @param[in] value     to convert.
 * @param[in] quote     to use when allocing the pair.
 * @param[in] rule      UNUSED.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int kafka_config_dflt_single(CONF_PAIR **out, UNUSED void *parent, CONF_SECTION *cs, char const *value,
                                    fr_token_t quote, conf_parser_t const *rule)
{
        char                            tmp[sizeof("18446744073709551615b")];
        fr_kafka_conf_ctx_t const       *kctx = rule->uctx;
        fr_type_t                       type = rule->type;
 
        /*
         *      Apply any mappings available, but default back
         *      to the raw value if we don't have a match.
         */
        if (kctx->mapping) {
                fr_table_ptr_sorted_t   *mapping = kctx->mapping;
                size_t                  mapping_len = *kctx->mapping_len;
 
                value = fr_table_str_by_str_value(mapping, value, value);
        }
        /*
         *      Convert time delta as an integer with ms precision
         */
        switch (type) {
        case FR_TYPE_TIME_DELTA:
        {
                fr_sbuff_t      value_elem = FR_SBUFF_IN(tmp, sizeof(tmp));
                fr_time_delta_t delta;
 
                if (fr_time_delta_from_str(&delta, value, strlen(value), FR_TIME_RES_MSEC) < 0) {
                        cf_log_perr(cs, "Failed parsing default \"%s\"", value);
                        return -1;
                }
 
                fr_time_delta_to_str(&value_elem, delta, FR_TIME_RES_SEC, true);
                value = fr_sbuff_start(&value_elem);
        }
                break;
 
        case FR_TYPE_SIZE:
        {
                fr_sbuff_t      value_elem = FR_SBUFF_IN(tmp, sizeof(tmp));
                size_t          size;
 
                if (fr_size_from_str(&size, &FR_SBUFF_IN_STR(value)) < 0) {
                        cf_log_perr(cs, "Failed parsing default \"%s\"", value);
                        return -1;
                }
 
                /*
                 *      Some options are in kbytes *sigh*
                 */
                if (kctx->size_scale) size *= kctx->size_scale;
 
                /*
                 *      reprint the size with an appropriate unit
                 */
                if (fr_size_to_str(&value_elem, size) < 0) {
                        cf_log_perr(cs, "Failed size reprint");
                        return -1;
                }
                value = fr_sbuff_start(&value_elem);
        }
                break;
 
        default:
                break;
        }
 
        MEM(*out = cf_pair_alloc(cs, rule->name1, value, T_OP_EQ, T_BARE_WORD, quote));
        cf_item_mark_parsed(*out);      /* Don't re-parse this */
 
        return 0;
}
 
/** No-op parser used to reserve CONF_PAIR names inside a topic subsection
 *  that the module reads separately (via call_env), so they aren't caught
 *  by the trailing raw-passthrough catch-all and fed to librdkafka.
 */
static int kafka_noop_parse(UNUSED TALLOC_CTX *ctx, UNUSED void *out, UNUSED void *base,
                            UNUSED CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        return 0;
}
 
/** @} */
 
/** @name Base conf (`fr_kafka_conf_t`)
 *
 * Lifecycle, lazy-init + talloc sentinel, and the FR_CONF_PAIR_GLOBAL parsers for
 * the top-level `kafka { ... }` section.
 *
 * @{
 */
 
/** Destructor on the talloc sentinel that owns the rd_kafka_conf_t handle
 *
 * The sentinel is just a talloced `rd_kafka_conf_t *` attached to the
 * caller's parse ctx - when talloc unwinds the instance, this fires and
 * releases the librdkafka handle.
 */
static int _kafka_conf_free(rd_kafka_conf_t **pconf)
{
        if (*pconf) rd_kafka_conf_destroy(*pconf);
        return 0;
}
 
/** Fetch the `fr_kafka_conf_t` currently being populated by the parser
 *
 * The parser contract is that `base` points at the caller's instance
 * struct and `fr_kafka_conf_t` is its first member, so a reinterpret
 * cast of `base` is the `fr_kafka_conf_t`.
 *
 * Also lazy-initialises the underlying librdkafka conf the first time
 * we see it, attaching a talloc sentinel under the parse ctx so the
 * handle is released when the caller's instance tree unwinds.
 */
static fr_kafka_conf_t *kafka_conf_get(TALLOC_CTX *ctx, void *base)
{
        fr_kafka_conf_t *kc = base;
 
        if (!kc) return NULL;
        if (!kc->conf) {
                rd_kafka_conf_t **s;
 
                MEM(kc->conf = rd_kafka_conf_new());
 
                /*
                 *      Attach a sentinel under the parse ctx so teardown
                 *      of the caller's instance data automatically releases
                 *      the librdkafka handle.
                 */
                MEM(s = talloc(ctx, rd_kafka_conf_t *));
                *s = kc->conf;
                talloc_set_destructor(s, _kafka_conf_free);
        }
        return kc;
}
 
/** Translate config items directly to settings in a kafka config struct
 *
 * @param[in] ctx       to allocate fr_kafka_conf_t in.
 * @param[out] out      Unused.
 * @param[in] base      Unused.
 * @param[in] ci        To parse.
 * @param[in] rule      describing how to parse the item.
 * @return
 *      - 0 on success.
 *      - -1 on failure
 */
int kafka_config_parse(TALLOC_CTX *ctx, UNUSED void *out, void *base,
                       CONF_ITEM *ci, conf_parser_t const *rule)
{
        fr_kafka_conf_ctx_t const       *kctx = rule->uctx;
        CONF_ITEM                       *parent = cf_parent(ci);
        CONF_SECTION                    *cs = cf_item_to_section(parent);
        CONF_PAIR                       *cp = cf_item_to_pair(ci);
 
        fr_kafka_conf_t                 *kc;
        char const                      *value;
 
        kc = kafka_conf_get(ctx, base);
        fr_assert_msg(kc, "kafka base struct missing - caller must embed fr_kafka_conf_t as first member");
 
        /*
         *      Multi rules require us to concat the values together before handing them off
         */
        if (fr_rule_multi(rule)) {
                unsigned int    i;
                CONF_PAIR       *cp_p;
                size_t          count;
                char const      **array;
                fr_sbuff_t      *agg;
                fr_slen_t       slen;
 
                FR_SBUFF_TALLOC_THREAD_LOCAL(&agg, 256, SIZE_MAX);
 
                count = cf_pair_count(cs,  rule->name1);
                if (count <= 1) goto do_single;
 
                MEM(array = talloc_array(ctx, char const *, count));
                for (cp_p = cp, i = 0;
                     cp_p;
                     cp_p = cf_pair_find_next(cs, cp_p, rule->name1), i++) {
                        if (kafka_config_parse_single(&array[i], cp_p, rule) < 0) return -1;
                        cf_item_mark_parsed(cp_p);
                }
 
                slen = fr_sbuff_array_concat(agg, array, kctx->string_sep);
                talloc_free(array);
                if (slen < 0) return -1;
 
                value = fr_sbuff_start(agg);
        } else {
        do_single:
                if (kafka_config_parse_single(&value, cp, rule) < 0) return -1;
        }
 
        {
                char errstr[512];
 
                if (rd_kafka_conf_set(kc->conf, kctx->property,
                                      value, errstr, sizeof(errstr)) != RD_KAFKA_CONF_OK) {
                        cf_log_perr(cp, "%s", errstr);
                        return -1;
                }
        }
 
        return 0;
}
 
/** Return the default value from the kafka client library
 *
 * @param[out] out      Where to write the pair.
 * @param[in] parent    being populated.
 * @param[in] cs        to allocate the pair in.
 * @param[in] quote     to use when allocing the pair.
 * @param[in] rule      UNUSED.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int kafka_config_dflt(CONF_PAIR **out, void *parent, CONF_SECTION *cs, fr_token_t quote, conf_parser_t const *rule)
{
        char                            buff[1024];
        size_t                          buff_len = sizeof(buff);
        char const                      *value;
 
        fr_kafka_conf_t                 *kc;
        fr_kafka_conf_ctx_t const       *kctx = rule->uctx;
        rd_kafka_conf_res_t             ret;
 
        kc = kafka_conf_get(cs, parent);
        fr_assert_msg(kc, "kafka base struct missing during default generation");
 
        if ((ret = rd_kafka_conf_get(kc->conf, kctx->property, buff, &buff_len)) != RD_KAFKA_CONF_OK) {
                if (ret == RD_KAFKA_CONF_UNKNOWN) {
                        if (kctx->empty_default) return 0;
 
                        cf_log_debug(cs, "No default available for \"%s\" - \"%s\"", rule->name1, kctx->property);
                        return 0;       /* Not an error */
                }
 
                cf_log_err(cs, "Failed retrieving kafka property \"%s\"", kctx->property);
                return -1;
        }
#if 0
        cf_log_debug(cs, "Retrieved dflt \"%s\" for \"%s\" - \"%s\"", buff, rule->name1, kctx->property);
#endif
        value = buff;
 
        /*
         *      If it's multi we need to break the string apart on the string separator
         *      and potentially unescape the separator.
         */
        if (fr_rule_multi(rule)) {
                fr_sbuff_t                      value_in = FR_SBUFF_IN(value, buff_len);
                char                            tmp[256];
                fr_sbuff_t                      value_elem = FR_SBUFF_OUT(tmp, sizeof(tmp));
                /*
                 *      FR_SBUFF_TERM() uses sizeof() on its argument, which
                 *      produces the wrong length for a runtime pointer.  Build
                 *      the terminator list by hand so the length is correct.
                 */
                fr_sbuff_term_elem_t            tt_elem = { .str = kctx->string_sep, .len = strlen(kctx->string_sep) };
                fr_sbuff_term_t                 tt = { .len = 1, .elem = &tt_elem };
                fr_sbuff_unescape_rules_t       ue_rules = {
                                                        .name = __FUNCTION__,
                                                        .chr = '\\'
                                                };
                /*
                 *      Convert escaped separators back
                 */
                ue_rules.subs[(uint8_t)kctx->string_sep[0]] = kctx->string_sep[0];
 
                while (fr_sbuff_out_unescape_until(&value_elem, &value_in, SIZE_MAX, &tt, &ue_rules) > 0) {
                        if (kafka_config_dflt_single(out, parent, cs, fr_sbuff_start(&value_elem), quote, rule) < 0) return -1;
 
                        /*
                         *      Skip past the string separator
                         */
                        fr_sbuff_advance(&value_in, strlen(kctx->string_sep));
 
                        /*
                         *      Reset
                         */
                        fr_sbuff_set_to_start(&value_elem);
                }
                return 0;
        }
 
        /*
         *      Parse a single value
         */
        if (kafka_config_dflt_single(out, parent, cs, value, quote, rule) < 0) return -1;
 
        return 0;
}
 
/** Untyped passthrough: hand a CONF_PAIR's attr/value straight to rd_kafka_conf_set
 *
 * Used by the `CF_IDENT_ANY` entry in the base `properties { }` subsection
 * to accept arbitrary librdkafka properties that don't have a typed entry
 * in `KAFKA_BASE_CONFIG` / `KAFKA_PRODUCER_CONFIG` / `KAFKA_CONSUMER_CONFIG`.
 * No unit scaling, no bool mapping - the user writes what librdkafka
 * expects (e.g. "500" for a ms value, "1048576" for a byte count).
 */
int kafka_config_raw_parse(TALLOC_CTX *ctx, UNUSED void *out, void *base,
                           CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        CONF_PAIR               *cp = cf_item_to_pair(ci);
        fr_kafka_conf_t         *kc;
        char                    errstr[512];
 
        kc = kafka_conf_get(ctx, base);
        fr_assert_msg(kc, "kafka base struct missing - caller must embed fr_kafka_conf_t as first member");
 
        if (rd_kafka_conf_set(kc->conf, cf_pair_attr(cp), cf_pair_value(cp),
                              errstr, sizeof(errstr)) != RD_KAFKA_CONF_OK) {
                cf_log_perr(cp, "%s", errstr);
                return -1;
        }
        return 0;
}
 
/** @} */
 
/** @name Topic conf (`fr_kafka_topic_conf_t` + `fr_kafka_topic_t`)
 *
 * Per-topic lifecycle, FR_CONF_PAIR_GLOBAL parsers for entries inside a declared
 * topic subsection, and the subsection hook that indexes each declared
 * topic onto `fr_kafka_conf_t.topics`.
 *
 * @{
 */
 
/** Destructor on a per-topic conf - releases the librdkafka handle. */
static int _kafka_topic_conf_free(fr_kafka_topic_conf_t *ktc)
{
        if (ktc->rdtc) rd_kafka_topic_conf_destroy(ktc->rdtc);
        return 0;
}
 
/** Allocate a per-topic conf parented under `ctx`
 *
 * Used by the subsection hook to build each declared topic's
 * `fr_kafka_topic_conf_t`.  The destructor releases the librdkafka
 * handle when the owning `fr_kafka_topic_t` is freed.
 */
static fr_kafka_topic_conf_t *kafka_topic_conf_alloc(TALLOC_CTX *ctx)
{
        fr_kafka_topic_conf_t   *ktc;
 
        MEM(ktc = talloc(ctx, fr_kafka_topic_conf_t));
        MEM(ktc->rdtc = rd_kafka_topic_conf_new());
        talloc_set_destructor(ktc, _kafka_topic_conf_free);
        return ktc;
}
 
/** Translate config items directly to settings in a kafka topic config struct
 *
 * `base` is the `fr_kafka_topic_conf_t` the per-topic subsection hook
 * handed down, so we write directly through it instead of re-fetching
 * via cf_data.  Falls back to cf_data lookup if a caller runs this
 * parser outside `kafka_topic_subsection_parse`.
 *
 * @param[in] ctx       UNUSED.
 * @param[out] out      UNUSED.
 * @param[in] base      topic-level conf (`fr_kafka_topic_conf_t *`).
 * @param[in] ci        To parse.
 * @param[in] rule      describing how to parse the item.
 * @return
 *      - 0 on success.
 *      - -1 on failure
 */
static int kafka_topic_config_parse(UNUSED TALLOC_CTX *ctx, UNUSED void *out, void *base,
                                    CONF_ITEM *ci, conf_parser_t const *rule)
{
        fr_kafka_conf_ctx_t const       *kctx = rule->uctx;
        CONF_PAIR                       *cp = cf_item_to_pair(ci);
 
        fr_kafka_topic_conf_t           *ktc = base;
        char const                      *value;
 
        fr_assert_msg(ktc, "kafka topic conf missing - topic parser invoked without subsection hook");
        if (kafka_config_parse_single(&value, cp, rule) < 0) return -1;
 
        {
                char errstr[512];
 
                if (rd_kafka_topic_conf_set(ktc->rdtc, kctx->property,
                                            value, errstr, sizeof(errstr)) != RD_KAFKA_CONF_OK) {
                        cf_log_perr(cp, "%s", errstr);
                        return -1;
                }
        }
 
        return 0;
}
 
/** Return the default value for a topic from the kafka client library
 *
 * @param[out] out      Where to write the pair.
 * @param[in] parent    being populated.
 * @param[in] cs        to allocate the pair in.
 * @param[in] quote     to use when allocing the pair.
 * @param[in] rule      UNUSED.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int kafka_topic_config_dflt(CONF_PAIR **out, void *parent, CONF_SECTION *cs, fr_token_t quote, conf_parser_t const *rule)
{
        char                            buff[1024];
        size_t                          buff_len = sizeof(buff);
        char const                      *value;
 
        fr_kafka_topic_conf_t           *ktc = parent;
        fr_kafka_conf_ctx_t const       *kctx = rule->uctx;
        rd_kafka_conf_res_t             ret;
 
        fr_assert_msg(ktc, "kafka topic conf missing during default generation");
 
        if ((ret = rd_kafka_topic_conf_get(ktc->rdtc, kctx->property, buff, &buff_len)) != RD_KAFKA_CONF_OK) {
                if (ret == RD_KAFKA_CONF_UNKNOWN) {
                        if (kctx->empty_default) return 0;
 
                        cf_log_debug(cs, "No default available for \"%s\" - \"%s\"", rule->name1, kctx->property);
                        return 0;       /* Not an error */
                }
 
                cf_log_err(cs, "Failed retrieving kafka property '%s'", kctx->property);
                return -1;
        }
#if 0
        cf_log_debug(cs, "Retrieved dflt \"%s\" for \"%s\" - \"%s\"", buff, rule->name1, kctx->property);
#endif
        value = buff;
 
        /*
         *      Parse a single value
         */
        if (kafka_config_dflt_single(out, parent, cs, value, quote, rule) < 0) return -1;
 
        return 0;
}
 
/** Topic-level counterpart to `kafka_config_raw_parse`
 *
 * Used inside a declared topic's `properties { }` subsection to accept
 * arbitrary `rd_kafka_topic_conf_set` properties.  `base` is the enclosing
 * topic's `fr_kafka_topic_conf_t`, handed down by the subsection hook.
 */
int kafka_topic_config_raw_parse(UNUSED TALLOC_CTX *ctx, UNUSED void *out, void *base,
                                 CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        CONF_PAIR               *cp = cf_item_to_pair(ci);
        fr_kafka_topic_conf_t   *ktc = base;
        char                    errstr[512];
 
        fr_assert_msg(ktc, "kafka topic conf missing - raw parser invoked without subsection hook");
 
        if (rd_kafka_topic_conf_set(ktc->rdtc, cf_pair_attr(cp), cf_pair_value(cp),
                                    errstr, sizeof(errstr)) != RD_KAFKA_CONF_OK) {
                cf_log_perr(cp, "%s", errstr);
                return -1;
        }
        return 0;
}
 
/** Order-by-name comparator for the `fr_kafka_conf_t.topics` tree. */
static int8_t _kafka_topic_cmp(void const *one, void const *two)
{
        fr_kafka_topic_t const  *a = one;
        fr_kafka_topic_t const  *b = two;
        return CMP(strcmp(a->name, b->name), 0);
}
 
fr_kafka_topic_t *kafka_topic_conf_find(fr_kafka_conf_t const *kc, char const *name)
{
        fr_kafka_topic_t        key;
 
        if (!kc || !kc->topics || !name) return NULL;
        key.name = name;
        return fr_rb_find(kc->topics, &key);
}
 
/** Per-topic subsection hook.  Runs the inner rules against the topic's
 *  section, then inserts a record into the parent's topics tree.
 *
 * Invoked by the framework for each `<name> { ... }` inside `topic { }`.
 * `ci` is the topic's CONF_SECTION, `base` points at the caller's instance
 * struct (with `fr_kafka_conf_t` as its first member).
 */
int kafka_topic_subsection_parse(TALLOC_CTX *ctx, void *out, void *base,
                                 CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        CONF_SECTION            *subcs = cf_item_to_section(ci);
        fr_kafka_conf_t         *kc;
        fr_kafka_topic_t        *topic;
        char const              *name = cf_section_name1(subcs);
 
        fr_assert_msg(base, "kafka base struct missing");
 
        kc = kafka_conf_get(ctx, base);
        if (!kc->topics) {
                MEM(kc->topics = fr_rb_inline_talloc_alloc(ctx, fr_kafka_topic_t, node, _kafka_topic_cmp, NULL));
        }
 
        /*
         *      Allocate eagerly so the inner parsers can write into
         *      topic->conf via `base` instead of round-tripping through
         *      cf_data.
         */
        MEM(topic = talloc_zero(kc->topics, fr_kafka_topic_t));
        topic->name = talloc_strdup(topic, name);
        topic->conf = kafka_topic_conf_alloc(topic);
        topic->cs = subcs;
 
        /*
         *      Inner rules (acks, compression, properties, ...) have been
         *      pushed on the subsection by the framework.  Run them with
         *      topic->conf as base so they write directly into our struct.
         */
        if (cf_section_parse(ctx, topic->conf, subcs) < 0) {
                talloc_free(topic);
                return -1;
        }
 
        if (!fr_rb_insert(kc->topics, topic)) {
                cf_log_err(ci, "Duplicate kafka topic '%s'", name);
                talloc_free(topic);
                return -1;
        }
 
        /*
         *      If the caller wired an output target on the subsection
         *      rule, hand back the topic pointer so it lands in their
         *      array.  The tree on kc->topics is the primary index;
         *      this is just a convenience for direct-access patterns.
         */
        if (out) *((fr_kafka_topic_t **)out) = topic;
 
        return 0;
}
/** @} */
 
/** @name `conf_parser_t` arrays
 *
 * Nested subsections referenced by the `KAFKA_BASE_CONFIG` /
 * `KAFKA_PRODUCER_CONFIG` / `KAFKA_CONSUMER_CONFIG` macros in base.h.
 * Base-level surfaces first, then producer-specific, then consumer.
 *
 * @{
 */
 
/** `properties { ... }` escape-hatch contents
 *
 * Accepts any `key = value` pair and hands it straight to
 * `rd_kafka_conf_set`.  See `kafka_config_raw_parse`.
 */
conf_parser_t const kafka_base_properties_config[] = {
        { .name1 = CF_IDENT_ANY, .func = kafka_config_raw_parse },
        CONF_PARSER_TERMINATOR
};
 
/** Per-topic `properties { ... }` escape-hatch contents
 *
 * Same idea as `kafka_base_properties_config`, but dispatches to
 * `rd_kafka_topic_conf_set` against the enclosing topic's conf.
 */
conf_parser_t const kafka_base_topic_properties_config[] = {
        { .name1 = CF_IDENT_ANY, .func = kafka_topic_config_raw_parse },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t const kafka_sasl_oauth_config[] = {
        { FR_CONF_PAIR_GLOBAL("oauthbearer_conf", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.oauthbearer.config", .empty_default = true }},
 
        { FR_CONF_PAIR_GLOBAL("unsecure_jwt", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "enable.sasl.oauthbearer.unsecure.jwt" }},
 
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t const kafka_sasl_kerberos_config[] = {
        /*
         *      Service principal
         */
        { FR_CONF_PAIR_GLOBAL("service_name", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.kerberos.service.name" }},
 
        /*
         *      Principal
         */
        { FR_CONF_PAIR_GLOBAL("principal", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.kerberos.principal" }},
 
        /*
         *      knit cmd
         */
        { FR_CONF_PAIR_GLOBAL("kinit_cmd", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.kerberos.kinit.cmd" }},
 
        /*
         *      keytab
         */
        { FR_CONF_PAIR_GLOBAL("keytab", FR_TYPE_STRING, CONF_FLAG_FILE_READABLE, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.kerberos.kinit.keytab", .empty_default = true }},
 
        /*
         *      How long between key refreshes
         */
        { FR_CONF_PAIR_GLOBAL("refresh_delay", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.kerberos.min.time.before.relogin" }},
 
        CONF_PARSER_TERMINATOR
};
 
conf_parser_t const kafka_sasl_config[] = {
        /*
         *      SASL mechanism
         */
        { FR_CONF_PAIR_GLOBAL("mech", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.mechanism" }},
 
        /*
         *      Static SASL username
         */
        { FR_CONF_PAIR_GLOBAL("username", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.username", .empty_default = true }},
 
        /*
         *      Static SASL password
         */
        { FR_CONF_PAIR_GLOBAL("password", FR_TYPE_STRING, CONF_FLAG_SECRET, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "sasl.password", .empty_default = true }},
 
        { FR_CONF_SUBSECTION_GLOBAL("kerberos", 0, kafka_sasl_kerberos_config) },
 
        { FR_CONF_SUBSECTION_GLOBAL("oauth", 0, kafka_sasl_oauth_config) },
 
        CONF_PARSER_TERMINATOR
};
 
static fr_table_ptr_sorted_t kafka_check_cert_cn_table[] = {
        { L("false"),   "none"  },
        { L("no"),      "none"  },
        { L("true"),    "https" },
        { L("yes"),     "https" }
};
static size_t kafka_check_cert_cn_table_len = NUM_ELEMENTS(kafka_check_cert_cn_table);
 
conf_parser_t const kafka_tls_config[] = {
        /*
         *      Cipher suite list in OpenSSL's format
         */
        { FR_CONF_PAIR_GLOBAL("cipher_list", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.cipher.suites", .empty_default = true }},
 
        /*
         *      Curves list in OpenSSL's format
         */
        { FR_CONF_PAIR_GLOBAL("curve_list", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.curves.list", .empty_default = true }},
 
        /*
         *      Curves list in OpenSSL's format
         */
        { FR_CONF_PAIR_GLOBAL("sigalg_list", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.sigalgs.list", .empty_default = true }},
 
        /*
         *      Sets the full path to a CA certificate (used to validate
         *      the certificate the server presents).
         */
        { FR_CONF_PAIR_GLOBAL("ca_file", FR_TYPE_STRING, CONF_FLAG_FILE_READABLE, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.ca.location", .empty_default = true }},
 
        /*
         *      Location of the CRL file.
         */
        { FR_CONF_PAIR_GLOBAL("crl_file", FR_TYPE_STRING, CONF_FLAG_FILE_READABLE, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.crl.location", .empty_default = true }},
 
        /*
         *      Sets the path to the public certificate file we present
         *      to the servers.
         */
        { FR_CONF_PAIR_GLOBAL("certificate_file", FR_TYPE_STRING, CONF_FLAG_FILE_READABLE, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.certificate.location", .empty_default = true }},
 
        /*
         *      Sets the path to the private key for our public
         *      certificate.
         */
        { FR_CONF_PAIR_GLOBAL("private_key_file", FR_TYPE_STRING, CONF_FLAG_FILE_READABLE, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.key.location", .empty_default = true }},
 
        /*
         *      Enable or disable certificate validation
         */
        { FR_CONF_PAIR_GLOBAL("require_cert", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "enable.ssl.certificate.verification" }},
 
        { FR_CONF_PAIR_GLOBAL("check_cert_cn", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "ssl.endpoint.identification.algorithm",
                                          .mapping = kafka_check_cert_cn_table,
                                          .mapping_len = &kafka_check_cert_cn_table_len }},
        CONF_PARSER_TERMINATOR
};
 
conf_parser_t const kafka_connection_config[] = {
        /*
         *      Socket timeout
         */
        { FR_CONF_PAIR_GLOBAL("timeout", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "socket.timeout.ms" }},
 
        /*
         *      Close broker connections after this period.
         */
        { FR_CONF_PAIR_GLOBAL("idle_timeout", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "connections.max.idle.ms" }},
 
        /*
         *      Maximum requests in flight (per connection).
         */
        { FR_CONF_PAIR_GLOBAL("max_requests_in_flight", FR_TYPE_UINT64, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "max.in.flight.requests.per.connection" }},
 
        /*
         *      Socket send buffer.
         */
        { FR_CONF_PAIR_GLOBAL("send_buff", FR_TYPE_UINT64, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "socket.send.buffer.bytes" }},
 
        /*
         *      Socket recv buffer.
         */
        { FR_CONF_PAIR_GLOBAL("recv_buff", FR_TYPE_UINT64, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "socket.receive.buffer.bytes" }},
 
        /*
         *      If true, send TCP keepalives
         */
        { FR_CONF_PAIR_GLOBAL("keepalive", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "socket.keepalive.enable" }},
 
        /*
         *      If true, disable nagle algorithm
         */
        { FR_CONF_PAIR_GLOBAL("nodelay", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "socket.nagle.disable" }},
 
        /*
         *      How long the DNS resolver cache is valid for
         */
        { FR_CONF_PAIR_GLOBAL("resolver_cache_ttl", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "broker.address.ttl" }},
 
        /*
         *      Should we use A records, AAAA records or either
         *      when resolving broker addresses
         */
        { FR_CONF_PAIR_GLOBAL("resolver_addr_family", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "broker.address.family" }},
 
        /*
         *      How many failures before we reconnect the connection
         */
        { FR_CONF_PAIR_GLOBAL("reconnection_failure_count", FR_TYPE_UINT32, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "socket.max.fails" }},
 
        /*
         *      Initial time to wait before reconnecting.
         */
        { FR_CONF_PAIR_GLOBAL("reconnection_delay_initial", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "reconnect.backoff.ms" }},
 
        /*
         *      Max time to wait before reconnecting.
         */
        { FR_CONF_PAIR_GLOBAL("reconnection_delay_max", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "reconnect.backoff.max.ms" }},
 
        CONF_PARSER_TERMINATOR
};
 
conf_parser_t const kafka_version_config[] = {
        /*
         *      Request the API version from connected brokers
         */
        { FR_CONF_PAIR_GLOBAL("request", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "api.version.request" }},
 
        /*
         *      How long to wait for a version response.
         */
        { FR_CONF_PAIR_GLOBAL("timeout", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "api.version.request.timeout.ms" }},
 
        /*
         *      How long to wait before retrying a version request.
         */
        { FR_CONF_PAIR_GLOBAL("retry_delay", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "api.version.fallback.ms" }},
 
        /*
         *      Default version to use if the version request fails.
         */
        { FR_CONF_PAIR_GLOBAL("default", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "broker.version.fallback" }},
 
        CONF_PARSER_TERMINATOR
};
 
conf_parser_t const kafka_metadata_config[] = {
        /*
         *      Interval between attempts to refresh metadata from brokers
         */
        { FR_CONF_PAIR_GLOBAL("refresh_interval", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "topic.metadata.refresh.interval.ms" }},
 
        /*
         *      Interval between attempts to refresh metadata from brokers
         */
        { FR_CONF_PAIR_GLOBAL("max_age", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "metadata.max.age.ms" }},
 
        /*
         *       Used when a topic loses its leader
         */
        { FR_CONF_PAIR_GLOBAL("fast_refresh_interval", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "topic.metadata.refresh.fast.interval.ms" }},
 
        /*
         *       Used when a topic loses its leader to prevent spurious metadata changes
         */
        { FR_CONF_PAIR_GLOBAL("max_propagation", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "topic.metadata.propagation.max.ms" }},
 
        /*
         *      Use sparse metadata requests which use less bandwidth maps
         */
        { FR_CONF_PAIR_GLOBAL("refresh_sparse", FR_TYPE_BOOL, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "topic.metadata.refresh.sparse" }},
 
        /*
         *      List of topics to ignore
         */
        { FR_CONF_PAIR_GLOBAL("blacklist", FR_TYPE_STRING, CONF_FLAG_MULTI, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "topic.blacklist", .string_sep = ",", .empty_default = true }},
 
        CONF_PARSER_TERMINATOR
};
 
/** @name Producer-specific topic config
 * @{
 */
 
static conf_parser_t const kafka_base_producer_topic_config[] = {
        /*
         *      Payload and key templates for `kafka.produce.<topic>`
         *      invocations.  Parsed at call_env time, but we reserve
         *      the names here so the raw-passthrough catch-all below
         *      doesn't try to hand them to rd_kafka_topic_conf_set.
         */
        { FR_CONF_PAIR_GLOBAL("value", FR_TYPE_STRING, 0, kafka_noop_parse, NULL) },
        { FR_CONF_PAIR_GLOBAL("key", FR_TYPE_STRING, 0, kafka_noop_parse, NULL) },
 
        /*
         *      This field indicates the number of acknowledgements the leader
         *      broker must receive from ISR brokers before responding to the request.
         */
        { FR_CONF_PAIR_GLOBAL("request_required_acks", FR_TYPE_INT16, 0, kafka_topic_config_parse, kafka_topic_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "request.required.acks" }},
 
        /*
         *      medium  The ack timeout of the producer request in milliseconds
         */
        { FR_CONF_PAIR_GLOBAL("request_timeout", FR_TYPE_TIME_DELTA, 0, kafka_topic_config_parse, kafka_topic_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "request.timeout.ms" }},
 
        /*
         *      Local message timeout
         */
        { FR_CONF_PAIR_GLOBAL("message_timeout", FR_TYPE_TIME_DELTA, 0, kafka_topic_config_parse, kafka_topic_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "message.timeout.ms" }},
 
        /*
         *      Partitioning strategy
         */
        { FR_CONF_PAIR_GLOBAL("partitioner", FR_TYPE_STRING, 0, kafka_topic_config_parse, kafka_topic_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "partitioner" }},
 
        /*
         *      compression codec to use for compressing message sets.
         */
        { FR_CONF_PAIR_GLOBAL("compression_type", FR_TYPE_STRING, 0, kafka_topic_config_parse, kafka_topic_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "compression.type" }},
 
        /*
         *      compression level to use
         */
        { FR_CONF_PAIR_GLOBAL("compression_level", FR_TYPE_INT8, 0, kafka_topic_config_parse, kafka_topic_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "compression.level" }},
 
        /*
         *      Escape hatch for rd_kafka_topic_conf_set properties not
         *      covered above.  Same shape as the top-level properties
         *      block but writes to the per-topic conf.
         */
        { FR_CONF_SUBSECTION_GLOBAL("properties", 0, kafka_base_topic_properties_config) },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 * Allows topic configurations in the format:
 *
 * topic {
 *   <name> {
 *     request_required_acks = ...
 *   }
 * }
 *
 */
conf_parser_t const kafka_base_producer_topics_config[] = {
        { FR_CONF_SUBSECTION_GLOBAL(CF_IDENT_ANY, CONF_FLAG_MULTI, kafka_base_producer_topic_config),
          .subcs_size = sizeof(fr_kafka_topic_conf_t), .subcs_type = "fr_kafka_topic_conf_t",
          .func = kafka_topic_subsection_parse },
 
        CONF_PARSER_TERMINATOR
};
 
/* The producer config now lives entirely in the `KAFKA_PRODUCER_CONFIG`
 * macro in base.h so callers can compose it with their own config entries.
 * See that macro for the full set of librdkafka pass-through properties. */
 
/** @} */
 
/** @name Consumer-specific topic + group config
 * @{
 */
 
conf_parser_t const kafka_consumer_group_config[] = {
        /*
         *      Group consumer is a member of
         */
        { FR_CONF_PAIR_GLOBAL("id", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "group.id" }},
 
        /*
         *      A unique identifier of the consumer instance provided by the end user
         */
        { FR_CONF_PAIR_GLOBAL("instance_id", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "group.instance.id" }},
 
        /*
         *      Range or roundrobin
         */
        { FR_CONF_PAIR_GLOBAL("partition_assignment_strategy", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "partition.assignment.strategy" }},
 
        /*
         *      Client group session and failure detection timeout.
         */
        { FR_CONF_PAIR_GLOBAL("session_timeout", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "session.timeout.ms" }},
 
        /*
         *      Group session keepalive heartbeat interval.
         */
        { FR_CONF_PAIR_GLOBAL("heartbeat_interval", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "heartbeat.interval.ms" }},
 
        /*
         *      How often to query for the current client group coordinator
         */
        { FR_CONF_PAIR_GLOBAL("coordinator_query_interval", FR_TYPE_TIME_DELTA, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "coordinator.query.interval.ms" }},
 
 
        CONF_PARSER_TERMINATOR
};
 
conf_parser_t const kafka_base_consumer_topic_config[] = {
        /*
         *      How many messages we process at a time
         *
         *      High numbers may starve the worker thread
         */
        { FR_CONF_PAIR_GLOBAL("max_messages_per_cycle", FR_TYPE_UINT32, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "consume.callback.max.messages" }},
 
        /*
         *      Action to take when there is no initial offset
         *      in offset store or the desired offset is out of range.
         */
        { FR_CONF_PAIR_GLOBAL("auto_offset_reset", FR_TYPE_STRING, 0, kafka_config_parse, kafka_config_dflt),
          .uctx = &(fr_kafka_conf_ctx_t){ .property = "auto.offset.reset" }},
 
        /*
         *      Escape hatch for rd_kafka_topic_conf_set properties not
         *      covered above.
         */
        { FR_CONF_SUBSECTION_GLOBAL("properties", 0, kafka_base_topic_properties_config) },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 * Allows topic configurations in the format:
 *
 * topic {
 *   <name> {
 *     request_required_acks = ...
 *   }
 * }
 *
 */
conf_parser_t const kafka_base_consumer_topics_config[] = {
        { FR_CONF_SUBSECTION_GLOBAL(CF_IDENT_ANY, CONF_FLAG_MULTI, kafka_base_consumer_topic_config),
          .subcs_size = sizeof(fr_kafka_topic_conf_t), .subcs_type = "fr_kafka_topic_conf_t",
          .func = kafka_topic_subsection_parse },
 
        CONF_PARSER_TERMINATOR
};
 
/* The consumer config now lives in the `KAFKA_CONSUMER_CONFIG` macro in
 * base.h so callers can compose it with their own entries. */
 
/** @} */
 
/** @name Library init
 *
 * librdkafka defers SSL / SASL / internal-refcount setup until the first
 * `rd_kafka_new()`.  Doing that lazily in a worker thread races the
 * server's own OpenSSL init and leaves the ordering non-deterministic,
 * so we kick it once at module load via `fr_kafka_init()`.  The counter
 * mirrors `fr_openssl_init()` in src/lib/tls/base.c.
 *
 * @{
 */
static uint32_t kafka_instance_count = 0;
 
static void _kafka_null_log_cb(UNUSED rd_kafka_t const *rk, UNUSED int level,
                               UNUSED char const *fac, UNUSED char const *buf)
{
        /* swallow the "no bootstrap brokers" warning from the dummy producer */
}
 
/** Drive librdkafka's lazy global init deterministically
 *
 * First call creates and immediately destroys a throwaway producer, which
 * walks all of librdkafka's one-shot init paths (SSL lock callbacks on
 * OpenSSL 1.0.2, SASL global init if compiled in, etc.).  Subsequent
 * calls just bump the refcount so multiple kafka-using modules can share
 * the init.
 */
int fr_kafka_init(void)
{
        rd_kafka_conf_t *conf;
        rd_kafka_t      *rk;
        char            errstr[512];
 
        if (kafka_instance_count > 0) {
                kafka_instance_count++;
                return 0;
        }
 
        conf = rd_kafka_conf_new();
        rd_kafka_conf_set_log_cb(conf, _kafka_null_log_cb);
 
        rk = rd_kafka_new(RD_KAFKA_PRODUCER, conf, errstr, sizeof(errstr));
        if (!rk) {
                fr_strerror_printf("Failed priming librdkafka globals: %s", errstr);
                return -1;
        }
        rd_kafka_destroy(rk);
 
        kafka_instance_count++;
        return 0;
}
 
/** Drop one ref to librdkafka's global init
 *
 * librdkafka refcounts its own globals internally; our counter just
 * pairs fr_kafka_init() calls so re-entrant module load/unload in test
 * harnesses does the right thing.
 */
void fr_kafka_free(void)
{
        if (kafka_instance_count == 0) return;
        kafka_instance_count--;
}
 
/** @} */
/** @} */