[PATCH v2 08/13] xenstore: modify init-xenstore-domain parameter syntax

[Juergen Gross <jgross@suse.com>]

init-xenstore-domain takes only positional parameters today. Change
this to a more flexible parameter syntax allowing to specify additional
options or to omit some.

Today the supported usage is:

init-xenstore-domain <xenstore-kernel> <memory_mb> <flask-label>
                     [<ramdisk-file>]

Modify this to:

init-xenstore-domain --kernel <xenstore-kernel>
                     --memory <memory_mb>
                     [--flask <flask-label>]
                     [--ramdisk <ramdisk-file>]

The flask label is made optional in order to support xenstore domains
without the need of a flask enabled hypervisor.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/helpers/init-xenstore-domain.c | 82 +++++++++++++++++++++++++++++-------
 1 file changed, 66 insertions(+), 16 deletions(-)

diff --git a/tools/helpers/init-xenstore-domain.c b/tools/helpers/init-xenstore-domain.c
index d3abec0..17f0151 100644
--- a/tools/helpers/init-xenstore-domain.c
+++ b/tools/helpers/init-xenstore-domain.c
@@ -4,6 +4,7 @@
 #include <string.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <getopt.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <xenctrl.h>
@@ -13,16 +14,42 @@
 #include <xen-xsm/flask/flask.h>
 
 static uint32_t domid = ~0;
+static char *kernel;
+static char *ramdisk;
+static char *flask;
+static int memory;
+
+static struct option options[] = {
+    { "kernel", 1, NULL, 'k' },
+    { "memory", 1, NULL, 'm' },
+    { "flask", 1, NULL, 'f' },
+    { "ramdisk", 1, NULL, 'r' },
+    { NULL, 0, NULL, 0 }
+};
+
+static void usage(void)
+{
+    fprintf(stderr,
+"Usage:\n"
+"\n"
+"init-xenstore-domain <options>\n"
+"\n"
+"where options may include:\n"
+"\n"
+"  --kernel <xenstore-kernel> kernel file of the xenstore domain, mandatory\n"
+"  --memory <memory size>     size of the domain in MB, mandatory\n"
+"  --flask <flask-label>      optional flask label of the domain\n"
+"  --ramdisk <ramdisk-file>   optional ramdisk file for the domain\n");
+}
 
-static int build(xc_interface *xch, int argc, char** argv)
+static int build(xc_interface *xch)
 {
     char cmdline[512];
     uint32_t ssid;
     xen_domain_handle_t handle = { 0 };
     int rv, xs_fd;
     struct xc_dom_image *dom = NULL;
-    int maxmem = atoi(argv[2]);
-    int limit_kb = (maxmem + 1)*1024;
+    int limit_kb = (memory + 1)*1024;
 
     xs_fd = open("/dev/xen/xenbus_backend", O_RDWR);
     if (xs_fd == -1) {
@@ -30,10 +57,14 @@ static int build(xc_interface *xch, int argc, char** argv)
         return -1;
     }
 
-    rv = xc_flask_context_to_sid(xch, argv[3], strlen(argv[3]), &ssid);
-    if (rv) {
-        fprintf(stderr, "xc_flask_context_to_sid failed\n");
-        goto err;
+    if (flask) {
+        rv = xc_flask_context_to_sid(xch, flask, strlen(flask), &ssid);
+        if (rv) {
+            fprintf(stderr, "xc_flask_context_to_sid failed\n");
+            goto err;
+        }
+    } else {
+        ssid = SECINITSID_DOMU;
     }
     rv = xc_domain_create(xch, ssid, handle, 0, &domid, NULL);
     if (rv) {
@@ -64,14 +95,14 @@ static int build(xc_interface *xch, int argc, char** argv)
     snprintf(cmdline, 512, "--event %d --internal-db", rv);
 
     dom = xc_dom_allocate(xch, cmdline, NULL);
-    rv = xc_dom_kernel_file(dom, argv[1]);
+    rv = xc_dom_kernel_file(dom, kernel);
     if (rv) {
         fprintf(stderr, "xc_dom_kernel_file failed\n");
         goto err;
     }
 
-    if (argc > 4) {
-        rv = xc_dom_ramdisk_file(dom, argv[4]);
+    if (ramdisk) {
+        rv = xc_dom_ramdisk_file(dom, ramdisk);
         if (rv) {
             fprintf(stderr, "xc_dom_ramdisk_file failed\n");
             goto err;
@@ -88,7 +119,7 @@ static int build(xc_interface *xch, int argc, char** argv)
         fprintf(stderr, "xc_dom_parse_image failed\n");
         goto err;
     }
-    rv = xc_dom_mem_init(dom, maxmem);
+    rv = xc_dom_mem_init(dom, memory);
     if (rv) {
         fprintf(stderr, "xc_dom_mem_init failed\n");
         goto err;
@@ -136,15 +167,34 @@ err:
 
 int main(int argc, char** argv)
 {
+    int opt;
     xc_interface *xch;
     struct xs_handle *xsh;
     char buf[16];
     int rv, fd;
 
-    if (argc < 4 || argc > 5) {
-        fprintf(stderr,
-            "Use: %s <xenstore-kernel> <memory_mb> <flask-label> [<ramdisk-file>]\n",
-            argv[0]);
+    while ((opt = getopt_long(argc, argv, "", options, NULL)) != -1) {
+        switch (opt) {
+        case 'k':
+            kernel = optarg;
+            break;
+        case 'm':
+            memory = strtol(optarg, NULL, 10);
+            break;
+        case 'f':
+            flask = optarg;
+            break;
+        case 'r':
+            ramdisk = optarg;
+            break;
+        default:
+            usage();
+            return 2;
+        }
+    }
+
+    if (optind != argc || !kernel || !memory) {
+        usage();
         return 2;
     }
 
@@ -154,7 +204,7 @@ int main(int argc, char** argv)
         return 1;
     }
 
-    rv = build(xch, argc, argv);
+    rv = build(xch);
 
     xc_interface_close(xch);
 
-- 
2.6.2