[PATCH 19 of 21] blktap3/drivers: Introduce tapdisk's main function

[Thanos Makatos <thanos.makatos@citrix.com>]

This patch copies from blktap2.5 tapdisk's main function.

Signed-off-by: Thanos Makatos <thanos.makatos@citrix.com>

diff --git a/tools/blktap3/drivers/tapdisk.c b/tools/blktap3/drivers/tapdisk.c
new file mode 100644
--- /dev/null
+++ b/tools/blktap3/drivers/tapdisk.c
@@ -0,0 +1,140 @@
+ /*
+  * Copyright (c) 2008, XenSource Inc.
+  * All rights reserved.
+  *
+  * Redistribution and use in source and binary forms, with or without
+  * modification, are permitted provided that the following conditions are met:
+  *     * Redistributions of source code must retain the above copyright
+  *       notice, this list of conditions and the following disclaimer.
+  *     * 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.
+  *     * Neither the name of XenSource Inc. nor the names of its contributors
+  *       may be used to endorse or promote products derived from this software
+  *       without specific prior written permission.
+  *
+  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+  * "AS IS" AND ANY EXPRESS 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 COPYRIGHT OWNER
+  * OR 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 <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "tapdisk.h"
+#include "tapdisk-utils.h"
+#include "tapdisk-server.h"
+#include "tapdisk-control.h"
+
+static void usage(const char *app, int err)
+{
+    fprintf(stderr, "usage: %s <-u uuid> <-c control socket>\n", app);
+    exit(err);
+}
+
+static FILE
+*fdup(FILE * stream __attribute__((unused)), const char *mode)
+{
+    int fd, err;
+    FILE *f;
+
+    fd = dup(STDOUT_FILENO);
+    if (fd < 0)
+        goto fail;
+
+    f = fdopen(fd, mode);
+    if (!f)
+        goto fail;
+
+    return f;
+
+  fail:
+    err = -errno;
+    if (fd >= 0)
+        close(fd);
+    errno = -err;
+
+    return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+    char *control;
+    int c, err, nodaemon;
+    FILE *out;
+
+    control = NULL;
+    nodaemon = 0;
+
+    while ((c = getopt(argc, argv, "Dh")) != -1) {
+        switch (c) {
+        case 'D':
+            nodaemon = 1;
+            break;
+        case 'h':
+            usage(argv[0], 0);
+            break;
+        default:
+            usage(argv[0], EINVAL);
+        }
+    }
+
+    if (optind != argc)
+        usage(argv[0], EINVAL);
+
+    err = tapdisk_server_init();
+    if (err) {
+        DPRINTF("failed to initialize server: %d\n", err);
+        goto out;
+    }
+
+    out = fdup(stdout, "w");
+    if (!out) {
+        err = -errno;
+        DPRINTF("failed to dup stdout: %d\n", err);
+        goto out;
+    }
+
+    if (!nodaemon) {
+        err = daemon(0, 0);
+        if (err) {
+            DPRINTF("failed to daemonize: %d\n", errno);
+            goto out;
+        }
+    }
+
+    tapdisk_start_logging("tapdisk", NULL);
+
+    err = tapdisk_control_open(&control);
+    if (err) {
+        DPRINTF("failed to open control socket: %d\n", err);
+        goto out;
+    }
+
+    err = tapdisk_server_complete();
+    if (err) {
+        DPRINTF("failed to complete server: %d\n", err);
+        goto out;
+    }
+
+    fprintf(out, "%s\n", control);
+    fclose(out);
+
+    err = tapdisk_server_run();
+
+  out:
+    tapdisk_control_close();
+    tapdisk_stop_logging();
+    return -err;
+}