tools: split up xen-init-dom0.c

Split up tools/helpers/xen-init-dom0.c in order to prepare reusing
generation of the json configuration by init-xenstore-domain.c.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

tools/helpers/Makefile

@@ -10,7 +10,7 @@ ifeq ($(CONFIG_Linux),y)
 PROGS += init-xenstore-domain
 endif
 
-XEN_INIT_DOM0_OBJS = xen-init-dom0.o
+XEN_INIT_DOM0_OBJS = xen-init-dom0.o init-dom-json.o
 $(XEN_INIT_DOM0_OBJS): CFLAGS += $(CFLAGS_libxentoollog)
 $(XEN_INIT_DOM0_OBJS): CFLAGS += $(CFLAGS_libxenstore)
 $(XEN_INIT_DOM0_OBJS): CFLAGS += $(CFLAGS_libxenlight)

tools/helpers/init-dom-json.c

@@ -0,0 +1,59 @@
+#include <err.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <xenctrl.h>
+#include <libxl.h>
+
+int gen_stub_json_config(uint32_t domid)
+{
+    int rc = 1;
+    xentoollog_logger_stdiostream *logger;
+    libxl_ctx *ctx;
+    libxl_domain_config dom_config;
+    char *json = NULL;
+
+    logger = xtl_createlogger_stdiostream(stderr, XTL_ERROR, 0);
+    if (!logger)
+        return 1;
+
+    if (libxl_ctx_alloc(&ctx, LIBXL_VERSION, 0,
+                        (xentoollog_logger *)logger)) {
+        fprintf(stderr, "cannot init libxl context\n");
+        goto outlog;
+    }
+
+    libxl_domain_config_init(&dom_config);
+
+    /* Generate stub JSON config. */
+    dom_config.c_info.type = LIBXL_DOMAIN_TYPE_PV;
+    libxl_domain_build_info_init_type(&dom_config.b_info,
+                                      LIBXL_DOMAIN_TYPE_PV);
+
+    json = libxl_domain_config_to_json(ctx, &dom_config);
+    /* libxl-json format requires the string ends with '\0'. Code
+     * snippet taken from libxl.
+     */
+    rc = libxl_userdata_store(ctx, domid, "libxl-json",
+                              (const uint8_t *)json,
+                              strlen(json) + 1 /* include '\0' */);
+    if (rc)
+        fprintf(stderr, "cannot store stub json config for domain %u\n", domid);
+
+    libxl_domain_config_dispose(&dom_config);
+    free(json);
+    libxl_ctx_free(ctx);
+outlog:
+    xtl_logger_destroy((xentoollog_logger *)logger);
+    return rc;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

tools/helpers/init-dom-json.h

@@ -0,0 +1,18 @@
+#ifndef __INIT_DOM_JSON_H
+#define __INIT_DOM_JSON_H
+
+/*
+ * Generate a stub JSON config for a domain with the given domid.
+ */
+int gen_stub_json_config(uint32_t domid);
+
+#endif
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */

tools/helpers/xen-init-dom0.c

@@ -1,65 +1,26 @@
-#include <err.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
 #include <stdio.h>
 
-#include <xentoollog.h>
 #include <xenstore.h>
-#include <libxl.h>
+
+#include "init-dom-json.h"
 
 #define DOMNAME_PATH   "/local/domain/0/name"
 #define DOMID_PATH     "/local/domain/0/domid"
 
-static libxl_ctx *ctx;
-static xentoollog_logger_stdiostream *logger;
-static struct xs_handle *xsh;
-
-static void ctx_alloc(void)
+int main(int argc, char **argv)
 {
-    if (libxl_ctx_alloc(&ctx, LIBXL_VERSION, 0,
-                        (xentoollog_logger *)logger)) {
-        fprintf(stderr, "cannot init libxl context\n");
-        exit(1);
-    }
+    int rc;
+    struct xs_handle *xsh;
+    char *domname_string = NULL, *domid_string = NULL;
+
     xsh = xs_open(0);
     if (!xsh) {
         fprintf(stderr, "cannot open xenstore connection\n");
         exit(1);
     }
-}
-
-static void ctx_free(void)
-{
-    if (ctx) {
-        libxl_ctx_free(ctx);
-        ctx = NULL;
-    }
-    if (logger) {
-        xtl_logger_destroy((xentoollog_logger *)logger);
-        logger = NULL;
-    }
-    if (xsh) {
-        xs_close(xsh);
-        xsh = NULL;
-    }
-}
-
-int main(int argc, char **argv)
-{
-    int rc;
-    libxl_domain_config dom0_config;
-    char *domname_string = NULL, *domid_string = NULL;
-    char *json = NULL;;
-
-    logger = xtl_createlogger_stdiostream(stderr, XTL_ERROR, 0);
-    if (!logger) exit(1);
-
-    atexit(ctx_free);
-
-    ctx_alloc();
-
-    libxl_domain_config_init(&dom0_config);
 
     /* Sanity check: this program can only be run once. */
     domid_string = xs_read(xsh, XBT_NULL, DOMID_PATH, NULL);
@@ -70,22 +31,9 @@ int main(int argc, char **argv)
         goto out;
     }
 
-    /* Generate stub JSON config. */
-    dom0_config.c_info.type = LIBXL_DOMAIN_TYPE_PV;
-    libxl_domain_build_info_init_type(&dom0_config.b_info,
-                                      LIBXL_DOMAIN_TYPE_PV);
-
-    json = libxl_domain_config_to_json(ctx, &dom0_config);
-    /* libxl-json format requires the string ends with '\0'. Code
-     * snippet taken from libxl.
-     */
-    rc = libxl_userdata_store(ctx, 0, "libxl-json",
-                              (const uint8_t *)json,
-                              strlen(json) + 1 /* include '\0' */);
-    if (rc) {
-        fprintf(stderr, "cannot store stub json config for Dom0\n");
+    rc = gen_stub_json_config(0);
+    if (rc)
         goto out;
-    }
 
     /* Write xenstore entries. */
     if (!xs_write(xsh, XBT_NULL, DOMID_PATH, "0", strlen("0"))) {
@@ -104,10 +52,9 @@ int main(int argc, char **argv)
     printf("Done setting up Dom0\n");
 
 out:
-    libxl_domain_config_dispose(&dom0_config);
     free(domid_string);
     free(domname_string);
-    free(json);
+    xs_close(xsh);
     return rc;
 }