bio_dedup_tests.c

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/*
 *   This library is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   This library 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
 *   Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
 
/** Tests for the dedup bio expiring entries after a reply
 *
 * @file src/lib/bio/test/bio_dedup_tests.c
 *
 * @copyright 2026 Network RADIUS SAS (legal@networkradius.com)
 */
#include <freeradius-devel/util/test/acutest_common_init.h>
#include <freeradius-devel/util/test/acutest_helpers.h>
 
#define _BIO_PRIVATE 1
#include <freeradius-devel/bio/bio_priv.h>
#include <freeradius-devel/util/rb.h>
#include <freeradius-devel/bio/dedup.h>
 
static int                      expired_count;
static fr_bio_dedup_entry_t     *saved_item;
 
static uint8_t                  request[4] = { 1, 2, 3, 4 };
static uint8_t                  reply[4] = { 5, 6, 7, 8 };
static int                      packet_ctx;             //!< the tests pass only the address of packet_ctx
 
static bool dedup_receive(UNUSED fr_bio_t *bio, fr_bio_dedup_entry_t *dedup_ctx, UNUSED void *pctx)
{
        saved_item = dedup_ctx;
        return true;
}
 
static void dedup_release(UNUSED fr_bio_t *bio, UNUSED fr_bio_dedup_entry_t *dedup_ctx,
                          fr_bio_dedup_release_reason_t reason)
{
        if (reason == FR_BIO_DEDUP_EXPIRED) expired_count++;
}
 
static fr_bio_dedup_entry_t *dedup_get_item(UNUSED fr_bio_t *bio, UNUSED void *pctx)
{
        return saved_item;
}
 
/** The stub transport returns a copy of request on every read, and reports every write as complete.
 */
static ssize_t stub_read(UNUSED fr_bio_t *bio, UNUSED void *pctx, void *buffer, size_t size)
{
        if (size < sizeof(request)) return fr_bio_error(BUFFER_TOO_SMALL);
 
        memcpy(buffer, request, sizeof(request));
        return sizeof(request);
}
 
static size_t                   stub_bytes;             //!< bytes of reply data which the stub transport has accepted
 
static ssize_t stub_write_all(UNUSED fr_bio_t *bio, UNUSED void *pctx, void const *buffer, size_t size)
{
        if (!buffer) return 0;          /* nothing to flush */
 
        stub_bytes += size;
        return size;
}
 
/** A stub transport write function which always returns IO_WOULD_BLOCK.
 */
static ssize_t stub_write_block(UNUSED fr_bio_t *bio, UNUSED void *pctx, UNUSED void const *buffer, UNUSED size_t size)
{
        return fr_bio_error(IO_WOULD_BLOCK);
}
 
/** A stub transport write function which accepts one byte of each write.
 */
static ssize_t stub_write_one(UNUSED fr_bio_t *bio, UNUSED void *pctx, void const *buffer, UNUSED size_t size)
{
        if (!buffer) return 0;
 
        stub_bytes++;
        return 1;
}
 
static fr_bio_t *stub_alloc(TALLOC_CTX *ctx)
{
        fr_bio_common_t *my;
 
        my = talloc_zero(ctx, fr_bio_common_t);
        if (!my) return NULL;
 
        my->bio.read = stub_read;
        my->bio.write = stub_write_all;
 
        return &my->bio;
}
 
/** Allocate a dedup bio with two entries and a one-second lifetime, in front of the stub transport.
 */
static fr_bio_t *test_dedup_alloc(TALLOC_CTX *ctx, fr_bio_dedup_config_t *cfg)
{
        fr_bio_t *stub;
 
        expired_count = 0;
        saved_item = NULL;
        stub_bytes = 0;
 
        cfg->el = fr_event_list_alloc(ctx, NULL, NULL);
        if (!cfg->el) return NULL;
 
        cfg->lifetime = fr_time_delta_from_sec(1);
 
        stub = stub_alloc(ctx);
        if (!stub) return NULL;
 
        return fr_bio_dedup_alloc(ctx, 2, dedup_receive, dedup_release, dedup_get_item, cfg, stub);
}
 
/** Read one request through the dedup bio, and attach reply to the dedup entry of the request.
 */
static bool test_read_request(fr_bio_t *dedup, uint8_t *buffer, size_t size)
{
        saved_item = NULL;
 
        if (fr_bio_read(dedup, &packet_ctx, buffer, size) != sizeof(request)) return false;
        if (!saved_item) return false;
 
        saved_item->reply = reply;
        saved_item->reply_size = sizeof(reply);
        saved_item->reply_ctx = &packet_ctx;
        return true;
}
 
/** Run every timer which is due within the next five seconds.
 */
static void test_run_timers(fr_bio_dedup_config_t *cfg)
{
        fr_time_t when = fr_time_add(fr_time(), fr_time_delta_from_sec(5));
 
        (void) fr_timer_list_run(cfg->el->tl, &when);
}
 
/** The dedup entry for a reply sent with fr_bio_dedup_respond() expires once the lifetime is over.
 *
 *  Regression test for dedup.md finding 1.  fr_bio_dedup_respond() and fr_bio_dedup_write() did not
 *  arm the expiry timer, so no entry expired.
 */
static void test_respond_expires(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup;
        uint8_t                 buffer[64];
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
 
        TEST_CHECK(test_read_request(dedup, buffer, sizeof(buffer)));
        if (!saved_item) goto done;
 
        TEST_CASE("fr_bio_dedup_respond() writes the reply");
        TEST_CHECK_RET((int) fr_bio_dedup_respond(dedup, saved_item), (int) sizeof(reply));
 
        TEST_CASE("the dedup entry expires once the lifetime is over");
        test_run_timers(&cfg);
        TEST_CHECK_RET(expired_count, 1);
 
done:
        talloc_free(ctx);
}
 
/** The dedup entry for a reply sent with fr_bio_write() expires once the lifetime is over.
 */
static void test_write_expires(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup;
        uint8_t                 buffer[64];
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
 
        TEST_CHECK(test_read_request(dedup, buffer, sizeof(buffer)));
        if (!saved_item) goto done;
 
        TEST_CASE("fr_bio_write() writes the reply");
        TEST_CHECK_RET((int) fr_bio_write(dedup, &packet_ctx, reply, sizeof(reply)), (int) sizeof(reply));
 
        TEST_CASE("the dedup entry expires once the lifetime is over");
        test_run_timers(&cfg);
        TEST_CHECK_RET(expired_count, 1);
 
done:
        talloc_free(ctx);
}
 
/** The expiry timer returns each expired entry to the free list, so the dedup bio reads more
 *  requests than the dedup bio has entries.
 *
 *  The UDP bio of the RADIUS server has 256 entries.  Without the fix for dedup.md finding 1, the UDP
 *  bio returned fr_bio_error(OOM) for every request after 256 replies.
 */
static void test_entries_are_reused(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup;
        uint8_t                 buffer[64];
        int                     i;
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
 
        TEST_CASE("a dedup bio with two entries finds a free entry for each of five requests");
        for (i = 0; i < 5; i++) {
                TEST_CHECK(test_read_request(dedup, buffer, sizeof(buffer)));
                TEST_MSG("request %d", i);
                if (!saved_item) break;
 
                TEST_CHECK_RET((int) fr_bio_dedup_respond(dedup, saved_item), (int) sizeof(reply));
                test_run_timers(&cfg);
        }
        TEST_CHECK_RET(expired_count, 5);
 
done:
        talloc_free(ctx);
}
 
/** Two entries with the same expiry time both expire.
 *
 *  See finding 1 in dedup.md.  The expiry tree compared only the expiry time, so the tree treated the
 *  second entry as a duplicate, and never inserted the second entry.
 */
static void test_equal_expiry(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup;
        fr_bio_dedup_entry_t    *first, *second;
        fr_time_t               expires;
        uint8_t                 buffer[64];
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
 
        TEST_CHECK(test_read_request(dedup, buffer, sizeof(buffer)));
        first = saved_item;
        if (!first) goto done;
        TEST_CHECK_RET((int) fr_bio_dedup_respond(dedup, first), (int) sizeof(reply));
 
        TEST_CHECK(test_read_request(dedup, buffer, sizeof(buffer)));
        second = saved_item;
        if (!second) goto done;
        TEST_CHECK_RET((int) fr_bio_dedup_respond(dedup, second), (int) sizeof(reply));
 
        TEST_CASE("fr_bio_dedup_entry_extend() gives both entries the same expiry time");
        expires = fr_time_add(fr_time(), fr_time_delta_from_sec(2));
        TEST_CHECK(fr_bio_dedup_entry_extend(dedup, first, expires) == 0);
        TEST_CHECK(fr_bio_dedup_entry_extend(dedup, second, expires) == 0);
 
        TEST_CASE("both entries expire");
        test_run_timers(&cfg);
        TEST_CHECK_RET(expired_count, 2);
 
done:
        talloc_free(ctx);
}
 
/** Call the dedup bio's write_resume callback, as fr_bio_packet_write_resume() does.
 */
static int test_write_resume(fr_bio_t *dedup)
{
        fr_bio_common_t *my = (fr_bio_common_t *) dedup;
 
        if (!my->priv_cb.write_resume) return -1;
 
        return my->priv_cb.write_resume(dedup);
}
 
/** Read a request, and respond while the stub transport is blocked, so that the reply goes on the
 *  pending list.
 */
static bool test_pending_reply(fr_bio_t *dedup, fr_bio_t *stub, uint8_t *buffer, size_t size)
{
        if (!test_read_request(dedup, buffer, size)) return false;
 
        stub->write = stub_write_block;
        return (fr_bio_dedup_respond(dedup, saved_item) == sizeof(reply));
}
 
/** write_resume sends a pending reply, and the dedup entry then expires once the lifetime is over.
 */
static void test_resume_sends_pending(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup, *stub;
        uint8_t                 buffer[64];
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
        stub = fr_bio_next(dedup);
 
        TEST_CASE("a reply written while the stub transport is blocked goes on the pending list");
        TEST_CHECK(test_pending_reply(dedup, stub, buffer, sizeof(buffer)));
        TEST_CHECK_RET((int) stub_bytes, 0);
 
        TEST_CASE("write_resume sends the pending reply");
        stub->write = stub_write_all;
        TEST_CHECK_RET(test_write_resume(dedup), 1);
        TEST_CHECK_RET((int) stub_bytes, (int) sizeof(reply));
 
        TEST_CASE("the dedup entry then expires once the lifetime is over");
        test_run_timers(&cfg);
        TEST_CHECK_RET(expired_count, 1);
 
done:
        talloc_free(ctx);
}
 
/** write_resume keeps the pending reply when the stub transport is still blocked.
 */
static void test_resume_still_blocked(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup, *stub;
        uint8_t                 buffer[64];
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
        stub = fr_bio_next(dedup);
 
        TEST_CHECK(test_pending_reply(dedup, stub, buffer, sizeof(buffer)));
 
        TEST_CASE("write_resume reports that writes are still blocked");
        TEST_CHECK_RET(test_write_resume(dedup), 0);
 
        TEST_CASE("write_resume kept the pending reply, and the next write_resume call sends the pending reply");
        stub->write = stub_write_all;
        TEST_CHECK_RET(test_write_resume(dedup), 1);
        TEST_CHECK_RET((int) stub_bytes, (int) sizeof(reply));
 
done:
        talloc_free(ctx);
}
 
/** When the stub transport writes only part of a pending reply, the next resume writes the rest.
 */
static void test_resume_partial(void)
{
        TALLOC_CTX              *ctx = talloc_init_const("test");
        fr_bio_dedup_config_t   cfg;
        fr_bio_t                *dedup, *stub;
        uint8_t                 buffer[64];
 
        dedup = test_dedup_alloc(ctx, &cfg);
        TEST_CHECK(dedup != NULL);
        if (!dedup) goto done;
        stub = fr_bio_next(dedup);
 
        TEST_CHECK(test_pending_reply(dedup, stub, buffer, sizeof(buffer)));
 
        TEST_CASE("the stub transport accepts one byte, so write_resume reports that writes are still blocked");
        stub->write = stub_write_one;
        TEST_CHECK_RET(test_write_resume(dedup), 0);
        TEST_CHECK_RET((int) stub_bytes, 1);
 
        TEST_CASE("the next write_resume call sends the rest of the reply exactly once");
        stub->write = stub_write_all;
        TEST_CHECK_RET(test_write_resume(dedup), 1);
        TEST_CHECK_RET((int) stub_bytes, (int) sizeof(reply));
 
done:
        talloc_free(ctx);
}
 
TEST_LIST = {
        { "respond_expires",            test_respond_expires },
        { "write_expires",              test_write_expires },
        { "entries_are_reused",         test_entries_are_reused },
        { "equal_expiry",               test_equal_expiry },
        { "resume_sends_pending",       test_resume_sends_pending },
        { "resume_still_blocked",       test_resume_still_blocked },
        { "resume_partial",             test_resume_partial },
        TEST_TERMINATOR
};