tools: Prepare further command line tool extensions

Allow to add more extension scripts to the command line tool. We define
a structure that describes an extension by command / subcommand and
provides help to be displayed by the tool. The extension script itself
has to be called jailhouse-<command>-<subcommand>. We look for it in
$PATH, extended by the tool's directory and /usr/lib/jailhouse.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

diff --git a/tools/jailhouse-cell-list b/tools/jailhouse-cell-list
index 2e48390d19ae7c5476ac26bcb567a47af713923e..e1195dabf8fe69b97a6aca4ff464e17b3ad52c12 100755 (executable)
--- a/tools/jailhouse-cell-list
+++ b/tools/jailhouse-cell-list
@@ -12,6 +12,7 @@
 
 import glob
 import os
+import sys
 
 
 def read_cpus(path):
@@ -43,6 +44,10 @@ def print_cpus(mask):
     return output.strip(",")
 
 
+if len(sys.argv) > 1:
+    print("usage: %s" % os.path.basename(sys.argv[0]).replace("-", " "))
+    exit(0 if sys.argv[1] in ("--help", "-h") else 1)
+
 cells = []
 for cell_path in glob.glob('/sys/devices/jailhouse/cells/*'):
     cells.append({

diff --git a/tools/jailhouse.c b/tools/jailhouse.c
index ab3704ef096b57977a96fd4d1c066a6cd48854a3..674d6186be8f728075bc599b9905331cb2612d23 100644 (file)
--- a/tools/jailhouse.c
+++ b/tools/jailhouse.c
@@ -27,10 +27,20 @@
 
 enum shutdown_load_mode {LOAD, SHUTDOWN};
 
-static void __attribute__((noreturn))
-help(const char *progname, int exit_status)
+struct extension {
+       char *cmd, *subcmd, *help;
+};
+
+static const struct extension extensions[] = {
+       { "cell", "list", "" },
+       { NULL }
+};
+
+static void __attribute__((noreturn)) help(char *prog, int exit_status)
 {
-       printf("%s { COMMAND | --help }\n"
+       const struct extension *ext;
+
+       printf("Usage: %s { COMMAND | --help }\n"
               "\nAvailable commands:\n"
               "   enable SYSCONFIG\n"
               "   disable\n"
@@ -39,12 +49,42 @@ help(const char *progname, int exit_status)
                        "[ -a | --address ADDRESS] ...\n"
               "   cell start { ID | [--name] NAME }\n"
               "   cell shutdown { ID | [--name] NAME }\n"
-              "   cell destroy { ID | [--name] NAME }\n"
-              "   cell list\n",
-              progname);
+              "   cell destroy { ID | [--name] NAME }\n",
+              basename(prog));
+       for (ext = extensions; ext->cmd; ext++)
+               printf("   %s %s %s\n", ext->cmd, ext->subcmd, ext->help);
+
        exit(exit_status);
 }
 
+static void call_extension_script(const char *cmd, int argc, char *argv[])
+{
+       const struct extension *ext;
+       char new_path[PATH_MAX];
+       char script[64];
+
+       if (argc < 3)
+               return;
+
+       for (ext = extensions; ext->cmd; ext++) {
+               if (strcmp(ext->cmd, cmd) != 0 ||
+                   strcmp(ext->subcmd, argv[2]) != 0)
+                       continue;
+
+               snprintf(new_path, sizeof(new_path), "PATH=%s:%s:%s",
+                       dirname(argv[0]), "/usr/lib/jailhouse",
+                       getenv("PATH") ? : "");
+               putenv(new_path);
+
+               snprintf(script, sizeof(script), "jailhouse-%s-%s",
+                        cmd, ext->subcmd);
+               execvp(script, &argv[2]);
+
+               perror("execvp");
+               exit(1);
+       }
+}
+
 static int open_dev()
 {
        int fd;
@@ -271,25 +311,6 @@ static int cell_simple_cmd(int argc, char *argv[], unsigned int command)
        return err;
 }
 
-static int cell_list(int argc, char *argv[])
-{
-       static const char *cell_list_cmd = "jailhouse-cell-list";
-       char new_path[PATH_MAX];
-       int err;
-
-       if (argc != 3)
-               help(argv[0], 1);
-
-       snprintf(new_path, sizeof(new_path), "PATH=%s:%s",
-                getenv("PATH") ? : "", dirname(argv[0]));
-       putenv(new_path);
-
-       err = execvp(cell_list_cmd, argv);
-
-       perror(cell_list_cmd);
-       return err;
-}
-
 static int cell_management(int argc, char *argv[])
 {
        int err;
@@ -297,20 +318,20 @@ static int cell_management(int argc, char *argv[])
        if (argc < 3)
                help(argv[0], 1);
 
-       if (strcmp(argv[2], "create") == 0)
+       if (strcmp(argv[2], "create") == 0) {
                err = cell_create(argc, argv);
-       else if (strcmp(argv[2], "load") == 0)
+       } else if (strcmp(argv[2], "load") == 0) {
                err = cell_shutdown_load(argc, argv, LOAD);
-       else if (strcmp(argv[2], "start") == 0)
+       } else if (strcmp(argv[2], "start") == 0) {
                err = cell_simple_cmd(argc, argv, JAILHOUSE_CELL_START);
-       else if (strcmp(argv[2], "shutdown") == 0)
+       } else if (strcmp(argv[2], "shutdown") == 0) {
                err = cell_shutdown_load(argc, argv, SHUTDOWN);
-       else if (strcmp(argv[2], "destroy") == 0)
+       } else if (strcmp(argv[2], "destroy") == 0) {
                err = cell_simple_cmd(argc, argv, JAILHOUSE_CELL_DESTROY);
-       else if (strcmp(argv[2], "list") == 0)
-               err = cell_list(argc, argv);
-       else
+       } else {
+               call_extension_script("cell", argc, argv);
                help(argv[0], 1);
+       }
 
        return err;
 }