Add async sub-library to libcrypto

Provides support for running asynchronous jobs. Currently this is completely
stand alone. Future commits will integrate this into libssl and s_server/
s_client. An asynchronous capable engine will be required to see any benefit
from this capability.

Reviewed-by: Rich Salz <rsalz@openssl.org>

1 files changed, 275 insertions, 0 deletions

diff --git a/crypto/async/async.c b/crypto/async/async.c
new file mode 100644
index 0000000..2f6eca1
--- /dev/null
+++ b/crypto/async/async.c
@@ -0,0 +1,275 @@
+/* crypto/async/async.c */
+/*
+ * Written by Matt Caswell (matt@openssl.org) for the OpenSSL project.
+ */
+/* ====================================================================
+ * Copyright (c) 2015 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ */
+
+#include <openssl/crypto.h>
+#include <openssl/async.h>
+#include <ucontext.h>
+#include <string.h>
+
+#define ASYNC_JOB_RUNNING   0
+#define ASYNC_JOB_PAUSING   1
+#define ASYNC_JOB_PAUSED    2
+#define ASYNC_JOB_STOPPING  3
+
+
+typedef struct async_ctx_st {
+    ucontext_t dispatcher;
+    ASYNC_JOB *currjob;
+} ASYNC_CTX;
+
+__thread ASYNC_CTX *ctx;
+
+struct async_job_st {
+    ucontext_t fibrectx;
+    int (*func)(void *);
+    void *funcargs;
+    int ret;
+    int status;
+};
+
+
+static ASYNC_CTX *ASYNC_CTX_new(void)
+{
+    ASYNC_CTX *nctx = NULL;
+
+    if(!(nctx = OPENSSL_malloc(sizeof (ASYNC_CTX)))) {
+        /* Error here */
+        goto err;
+    }
+
+    nctx->currjob = NULL;
+    ctx = nctx;
+
+    return nctx;
+err:
+    if(nctx) {
+        OPENSSL_free(nctx);
+    }
+
+    return NULL;
+}
+
+static int ASYNC_CTX_free(void)
+{
+    if(ctx) {
+        OPENSSL_free(ctx);
+    }
+
+    ctx = NULL;
+
+    return 1;
+}
+
+static ASYNC_JOB *ASYNC_JOB_new(void)
+{
+    ASYNC_JOB *job = NULL;
+    void *stack = NULL;
+
+    if(!(job = OPENSSL_malloc(sizeof (ASYNC_JOB)))) {
+        goto err;
+    }
+
+    if(!(stack = OPENSSL_malloc(SIGSTKSZ))) {
+        goto err;
+    }
+    if(getcontext(&job->fibrectx))
+        goto err;
+    job->fibrectx.uc_stack.ss_sp = stack;
+    job->fibrectx.uc_stack.ss_size = SIGSTKSZ;
+    job->fibrectx.uc_link = NULL;
+    job->status = ASYNC_JOB_RUNNING;
+    job->funcargs = NULL;
+
+    return job;
+err:
+    if(job) {
+        if(stack)
+            OPENSSL_free(stack);
+        OPENSSL_free(job);
+    }
+    return NULL;
+}
+
+static void ASYNC_JOB_free(ASYNC_JOB *job)
+{
+    if(job) {
+        if(job->funcargs)
+            OPENSSL_free(job->funcargs);
+        if(job->fibrectx.uc_stack.ss_sp)
+            OPENSSL_free(job->fibrectx.uc_stack.ss_sp);
+        OPENSSL_free(job);
+    }
+}
+
+static void ASYNC_start_func(void)
+{
+    ASYNC_JOB *job;
+
+    /* Run the job */
+    job = ctx->currjob;
+    job->ret = job->func(job->funcargs);
+
+    /* Stop the job */
+    job->status = ASYNC_JOB_STOPPING;
+    setcontext(&ctx->dispatcher);
+
+    /*
+     * Should not happen. Getting here will close the thread...can't do much
+     * about it
+     */
+}
+
+int ASYNC_start_job(ASYNC_JOB **job, int *ret, int (*func)(void *),
+                         void *args, size_t size)
+{
+    if(ctx || !ASYNC_CTX_new()) {
+        return ASYNC_ERR;
+    }
+
+    if(*job) {
+        ctx->currjob = *job;
+    }
+
+    getcontext(&ctx->dispatcher);
+
+    if(ctx->currjob) {
+        if(ctx->currjob->status == ASYNC_JOB_STOPPING) {
+            *ret = ctx->currjob->ret;
+            ASYNC_JOB_free(ctx->currjob);
+            ctx->currjob = NULL;
+            ASYNC_CTX_free();
+            return ASYNC_FINISH;
+        }
+
+        if(ctx->currjob->status == ASYNC_JOB_PAUSING) {
+            *job = ctx->currjob;
+            ctx->currjob->status = ASYNC_JOB_PAUSED;
+            ASYNC_CTX_free();
+            return ASYNC_PAUSE;
+        }
+
+        if(ctx->currjob->status == ASYNC_JOB_PAUSED) {
+            ctx->currjob = *job;
+            /* Resume previous job */
+            setcontext(&ctx->currjob->fibrectx);
+            /* Does not return */
+        }
+
+        /* Should not happen */
+        ASYNC_JOB_free(ctx->currjob);
+        ctx->currjob = NULL;
+        ASYNC_CTX_free();
+        return ASYNC_ERR;
+    }
+
+    /* Start a new job */
+    if(!(ctx->currjob = ASYNC_JOB_new())) {
+        ASYNC_CTX_free();
+        return ASYNC_ERR;
+    }
+
+    if(args != NULL) {
+        ctx->currjob->funcargs = OPENSSL_malloc(size);
+        if(!ctx->currjob->funcargs) {
+            ASYNC_JOB_free(ctx->currjob);
+            ctx->currjob = NULL;
+            ASYNC_CTX_free();
+            return ASYNC_ERR;
+        }
+        memcpy(ctx->currjob->funcargs, args, size);
+    } else {
+        ctx->currjob->funcargs = NULL;
+    }
+
+    ctx->currjob->func = func;
+    makecontext(&ctx->currjob->fibrectx, ASYNC_start_func, 0);
+    setcontext(&ctx->currjob->fibrectx);
+
+    /* Does not return except in error */
+    ASYNC_JOB_free(ctx->currjob);
+    ctx->currjob = NULL;
+    ASYNC_CTX_free();
+    return ASYNC_ERR;
+}
+
+
+int ASYNC_pause_job(void)
+{
+    ASYNC_JOB *job;
+
+    if(!ctx || !ctx->currjob)
+        return 0;
+
+    job = ctx->currjob;
+    job->status = ASYNC_JOB_PAUSING;
+
+    if(swapcontext(&job->fibrectx, &ctx->dispatcher)) {
+        /* Error */
+        return 0;
+    }
+
+    return 1;
+}
+
+int ASYNC_in_job(void)
+{
+    if(ctx)
+        return 1;
+
+    return 0;
+}
+
+int ASYNC_job_is_waiting(ASYNC_JOB *job)
+{
+    return job->status == ASYNC_JOB_PAUSED;
+}