temp: verify memory-bio up_ref fix

Author: aidangarske

.github/workflows/diag.yml

@@ -60,17 +60,22 @@ jobs:
           grep -v 'would read block' /tmp/c.out | head -12
           exit $rc
 
-      - name: memory-bio-dtls -- backtrace the dtls1.2 segfault
+      - name: memory-bio-dtls -- does the up_ref fix work
         if: always()
         run: |
           cd dtls
           export LD_LIBRARY_PATH=/tmp/inst/lib
+          gcc -g -O0 -o /tmp/mb13 memory-bio-dtls.c -I/tmp/inst/include \
+            -L/tmp/inst/lib -lwolfssl -lpthread -lm || exit 1
           sed 's/#ifdef WOLFSSL_DTLS13/#if 0/' memory-bio-dtls.c > /tmp/mb12.c
           gcc -g -O0 -o /tmp/mb12 /tmp/mb12.c -I/tmp/inst/include \
             -L/tmp/inst/lib -lwolfssl -lpthread -lm || exit 1
-          ulimit -c unlimited
-          echo "=== confirm the forced method:"
-          grep -n -A4 '#if 0' /tmp/mb12.c | head -8
-          echo "=== run under gdb:"
-          gdb -batch -ex run -ex 'thread apply all bt' --args /tmp/mb12 2>&1 \
-            | grep -vE '^\[|^Reading|^Downloading|^warning:' | tail -40
+          bad=0
+          for v in 13 12; do
+            timeout 15 /tmp/mb$v > /tmp/o$v.txt 2>&1
+            rc=$?
+            echo "=== DTLS 1.$v : rc=$rc (0=works, 124=hang, 139=segv)"
+            cat /tmp/o$v.txt | head -8
+            [ $rc -eq 0 ] || bad=1
+          done
+          exit $bad

dtls/memory-bio-dtls.c

@@ -119,8 +119,7 @@ static void* client_thread(void* args)
     } while (ret <= 0 &&
       ((err ==  WOLFSSL_ERROR_WANT_READ) || (err == WOLFSSL_ERROR_WANT_WRITE)));
 
-    /* clean up, wolfSSL_free would also free the WOLFSSL_BIO's so set as NULL
-     * since they are also being used with srv_ssl and will be free'd there. */
+    /* drops this thread's BIO references; srv_ssl still holds its own */
     wolfSSL_set_bio(cli_ssl, NULL, NULL);
     wolfSSL_free(cli_ssl);
     wolfSSL_CTX_free(cli_ctx);
@@ -147,6 +146,10 @@ int main()
 
     io.rbio = wolfSSL_BIO_new(wolfSSL_BIO_s_mem());
     io.wbio = wolfSSL_BIO_new(wolfSSL_BIO_s_mem());
+    /* cli_ssl and srv_ssl both use these, so take the second reference here or
+     * whichever side cleans up first frees them under the other. */
+    wolfSSL_BIO_up_ref(io.rbio);
+    wolfSSL_BIO_up_ref(io.wbio);
     sem_init(&io.bioSem, 0, 1);
 
     /* set up server */