Add a test for BIO_s_mem() when using datagrams

The previous commit added support to BIO_s_mem() for using datagrams. We
now add tests for that functionality.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18596)

3 files changed, 140 insertions, 1 deletions

diff --git a/test/build.info b/test/build.info
index 13653f9efa..2047cf29b8 100644
--- a/test/build.info
+++ b/test/build.info
@@ -63,7 +63,7 @@ IF[{- !$disabled{tests} -}]
           keymgmt_internal_test hexstr_test provider_status_test defltfips_test \
           bio_readbuffer_test user_property_test pkcs7_test upcallstest \
           provfetchtest prov_config_test rand_test ca_internals_test \
-          bio_tfo_test
+          bio_tfo_test membio_test
 
   IF[{- !$disabled{'deprecated-3.0'} -}]
     PROGRAMS{noinst}=enginetest
@@ -391,6 +391,10 @@ IF[{- !$disabled{tests} -}]
   INCLUDE[bio_tfo_test]=../include ../apps/include ..
   DEPEND[bio_tfo_test]=../libcrypto libtestutil.a
 
+  SOURCE[membio_test]=membio_test.c
+  INCLUDE[membio_test]=../include ../apps/include ..
+  DEPEND[membio_test]=../libcrypto libtestutil.a
+
   SOURCE[params_api_test]=params_api_test.c
   INCLUDE[params_api_test]=../include ../apps/include
   DEPEND[params_api_test]=../libcrypto libtestutil.a
diff --git a/test/membio_test.c b/test/membio_test.c
new file mode 100644
index 0000000000..d1b01061a9
--- /dev/null
+++ b/test/membio_test.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <openssl/bio.h>
+#include "testutil.h"
+
+static int test_dgram(void)
+{
+    BIO *bio = BIO_new(BIO_s_dgram_mem()), *rbio = NULL;
+    int testresult = 0;
+    const char msg1[] = "12345656";
+    const char msg2[] = "abcdefghijklmno";
+    const char msg3[] = "ABCDEF";
+    const char msg4[] = "FEDCBA";
+    char buf[80];
+
+    if (!TEST_ptr(bio))
+        goto err;
+
+    rbio = BIO_new_mem_buf(msg1, sizeof(msg1));
+    if (!TEST_ptr(rbio))
+        goto err;
+
+    /* Seeting the EOF return value on a non datagram mem BIO should be fine */
+    if (!TEST_int_gt(BIO_set_mem_eof_return(rbio, 0), 0))
+        goto err;
+
+    /* Setting the EOF return value on a datagram mem BIO should fail */
+    if (!TEST_int_le(BIO_set_mem_eof_return(bio, 0), 0))
+        goto err;
+
+    /* Write 4 dgrams */
+    if (!TEST_int_eq(BIO_write(bio, msg1, sizeof(msg1)), sizeof(msg1)))
+        goto err;
+    if (!TEST_int_eq(BIO_write(bio, msg2, sizeof(msg2)), sizeof(msg2)))
+        goto err;
+    if (!TEST_int_eq(BIO_write(bio, msg3, sizeof(msg3)), sizeof(msg3)))
+        goto err;
+    if (!TEST_int_eq(BIO_write(bio, msg4, sizeof(msg4)), sizeof(msg4)))
+        goto err;
+
+    /* Reading all 4 dgrams out again should all be the correct size */
+    if (!TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg1))
+            || !TEST_mem_eq(buf, sizeof(msg1), msg1, sizeof(msg1))
+            || !TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg2))
+            || !TEST_mem_eq(buf, sizeof(msg2), msg2, sizeof(msg2))
+            || !TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg3))
+            || !TEST_mem_eq(buf, sizeof(msg3), msg3, sizeof(msg3))
+            || !TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg4))
+            || !TEST_mem_eq(buf, sizeof(msg4), msg4, sizeof(msg4)))
+        goto err;
+
+    /* Interleaving writes and reads should be fine */
+    if (!TEST_int_eq(BIO_write(bio, msg1, sizeof(msg1)), sizeof(msg1)))
+        goto err;
+    if (!TEST_int_eq(BIO_write(bio, msg2, sizeof(msg2)), sizeof(msg2)))
+        goto err;
+    if (!TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg1))
+            || !TEST_mem_eq(buf, sizeof(msg1), msg1, sizeof(msg1)))
+        goto err;
+    if (!TEST_int_eq(BIO_write(bio, msg3, sizeof(msg3)), sizeof(msg3)))
+        goto err;
+    if (!TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg2))
+            || !TEST_mem_eq(buf, sizeof(msg2), msg2, sizeof(msg2))
+            || !TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg3))
+            || !TEST_mem_eq(buf, sizeof(msg3), msg3, sizeof(msg3)))
+        goto err;
+
+    /*
+     * Requesting less than the available data in a dgram should not impact the
+     * next packet.
+     */
+    if (!TEST_int_eq(BIO_write(bio, msg1, sizeof(msg1)), sizeof(msg1)))
+        goto err;
+    if (!TEST_int_eq(BIO_write(bio, msg2, sizeof(msg2)), sizeof(msg2)))
+        goto err;
+    if (!TEST_int_eq(BIO_read(bio, buf, /* Short buffer */ 2), 2)
+            || !TEST_mem_eq(buf, 2, msg1, 2))
+        goto err;
+    if (!TEST_int_eq(BIO_read(bio, buf, sizeof(buf)), sizeof(msg2))
+            || !TEST_mem_eq(buf, sizeof(msg2), msg2, sizeof(msg2)))
+        goto err;
+
+    /*
+     * Writing a zero length datagram will return zero, but no datagrams will
+     * be written. Attempting to read when there are no datagrams to read should
+     * return a negative result, but not eof. Retry flags will be set.
+     */
+    if (!TEST_int_eq(BIO_write(bio, NULL, 0), 0)
+            || !TEST_int_lt(BIO_read(bio, buf, sizeof(buf)), 0)
+            || !TEST_false(BIO_eof(bio))
+            || !TEST_true(BIO_should_retry(bio)))
+        goto err;
+
+    testresult = 1;
+ err:
+    BIO_free(rbio);
+    BIO_free(bio);
+    return testresult;
+}
+
+
+int setup_tests(void)
+{
+    if (!test_skip_common_options()) {
+        TEST_error("Error parsing test options\n");
+        return 0;
+    }
+
+    ADD_TEST(test_dgram);
+
+    return 1;
+}
diff --git a/test/recipes/04-test_membio.t b/test/recipes/04-test_membio.t
new file mode 100644
index 0000000000..58d1080fb8
--- /dev/null
+++ b/test/recipes/04-test_membio.t
@@ -0,0 +1,16 @@
+#! /usr/bin/env perl
+# Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the Apache License 2.0 (the "License").  You may not use
+# this file except in compliance with the License.  You can obtain a copy
+# in the file LICENSE in the source distribution or at
+# https://www.openssl.org/source/license.html
+
+use strict;
+use OpenSSL::Test;
+use OpenSSL::Test::Simple;
+use OpenSSL::Test::Utils;
+
+setup("test_membio");
+
+simple_test("test_membio", "membio_test");