[TOOLS] Modify xenstore_client.c to include a new utility, xenstore-chmod.

This utility permits developers and administrators to
manually change the permissions on arbitrary locations in XenStore
from the command line.  This is often helpful if you're trying to debug an
application that relies on XenStore and is encountering difficulties
with permissions.

Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil>

1 files changed, 104 insertions, 2 deletions

diff --git a/tools/xenstore/xenstore_client.c b/tools/xenstore/xenstore_client.c
index 07809e6c83..811c6acb6a 100644
--- a/tools/xenstore/xenstore_client.c
+++ b/tools/xenstore/xenstore_client.c
@@ -60,6 +60,8 @@ usage(const char *progname)
     errx(1, "Usage: %s [-h] [-s] [-t] key [...]", progname);
 #elif defined(CLIENT_exists) || defined(CLIENT_list)
     errx(1, "Usage: %s [-h] [-s] key [...]", progname);
+#elif defined(CLIENT_chmod)
+    errx(1, "Usage: %s [-h] [-s] key <mode [modes...]>", progname);
 #endif
 }
 
@@ -78,10 +80,61 @@ do_rm(char *path, struct xs_handle *xsh, xs_transaction_t xth)
 }
 #endif
 
+#if defined(CLIENT_chmod)
+#define PATH_SEP '/'
+#define MAX_PATH_LEN 256
+
+static void
+do_chmod(char *path, struct xs_permissions *perms, int nperms, int upto,
+	 int recurse, struct xs_handle *xsh, xs_transaction_t xth)
+{
+    int ret;
+
+    if (!path[0])
+	return;
+
+    ret = xs_set_permissions(xsh, xth, path, perms, nperms);
+    if (!ret)
+	err(1, "Error occurred setting permissions on '%s'", path);
+
+    if (upto) {
+	/* apply same permissions to all parent entries: */
+	char *path_sep_ptr = strrchr(path, PATH_SEP);
+	if (!path_sep_ptr)
+	    errx(1, "Unable to locate path separator '%c' in '%s'",
+		 PATH_SEP, path);
+	
+	*path_sep_ptr = '\0'; /* truncate path */
+	
+	do_chmod(path, perms, nperms, 1, 0, xsh, xth);
+
+	*path_sep_ptr = PATH_SEP;
+    }
+
+    if (recurse) {
+	char buf[MAX_PATH_LEN];
+
+	/* apply same permissions to all child entries: */
+	unsigned int xsval_n;
+	char **xsval = xs_directory(xsh, xth, path, &xsval_n);
+
+	if (xsval) {
+	    int i;
+	    for (i = 0; i < xsval_n; i++) {
+		snprintf(buf, MAX_PATH_LEN, "%s/%s", path, xsval[i]);
+
+		do_chmod(buf, perms, nperms, 0, 1, xsh, xth);
+	    }
+
+	    free(xsval);
+	}
+    }
+}
+#endif
 
 static int
 perform(int optind, int argc, char **argv, struct xs_handle *xsh,
-        xs_transaction_t xth, int prefix, int tidy)
+        xs_transaction_t xth, int prefix, int tidy, int upto, int recurse)
 {
     while (optind < argc) {
 #if defined(CLIENT_read)
@@ -168,6 +221,41 @@ perform(int optind, int argc, char **argv, struct xs_handle *xsh,
 	}
 	free(list);
 	optind++;
+#elif defined(CLIENT_chmod)
+#define MAX_PERMS 16
+	struct xs_permissions perms[MAX_PERMS];
+	int nperms = 0;
+	/* save path pointer: */
+	char *path = argv[optind++];
+	for (; argv[optind]; optind++, nperms++)
+	{
+	    if (MAX_PERMS <= nperms)
+		errx(1, "Too many permissions specified.  "
+		     "Maximum per invocation is %d.", MAX_PERMS);
+
+	    perms[nperms].id = atoi(argv[optind]+1);
+
+	    switch (argv[optind][0])
+	    {
+	    case 'n':
+		perms[nperms].perms = XS_PERM_NONE;
+		break;
+	    case 'r':
+		perms[nperms].perms = XS_PERM_READ;
+		break;
+	    case 'w':
+		perms[nperms].perms = XS_PERM_WRITE;
+		break;
+	    case 'b':
+		perms[nperms].perms = XS_PERM_READ | XS_PERM_WRITE;
+		break;
+	    default:
+		errx(1, "Invalid permission specification: '%c'",
+		     argv[optind][0]);
+	    }
+	}
+
+	do_chmod(path, perms, nperms, upto, recurse, xsh, xth);
 #endif
     }
 
@@ -183,6 +271,8 @@ main(int argc, char **argv)
     int ret = 0, socket = 0;
     int prefix = 0;
     int tidy = 0;
+    int upto = 0;
+    int recurse = 0;
 
     while (1) {
 	int c, index = 0;
@@ -193,6 +283,9 @@ main(int argc, char **argv)
 	    {"prefix", 0, 0, 'p'},
 #elif defined(CLIENT_rm)
             {"tidy",   0, 0, 't'},
+#elif defined(CLIENT_chmod)
+	    {"upto",    0, 0, 'u'},
+	    {"recurse", 0, 0, 'r'},
 #endif
 	    {0, 0, 0, 0}
 	};
@@ -202,6 +295,8 @@ main(int argc, char **argv)
 			"p"
 #elif defined(CLIENT_rm)
                         "t"
+#elif defined(CLIENT_chmod)
+			"ur"
 #endif
 			, long_options, &index);
 	if (c == -1)
@@ -222,6 +317,13 @@ main(int argc, char **argv)
 	case 't':
 	    tidy = 1;
 	    break;
+#elif defined(CLIENT_chmod)
+	case 'u':
+	    upto = 1;
+	    break;
+	case 'r':
+	    recurse = 1;
+	    break;
 #endif
 	}
     }
@@ -246,7 +348,7 @@ main(int argc, char **argv)
     if (xth == XBT_NULL)
 	errx(1, "couldn't start transaction");
 
-    ret = perform(optind, argc, argv, xsh, xth, prefix, tidy);
+    ret = perform(optind, argc, argv, xsh, xth, prefix, tidy, upto, recurse);
 
     if (!xs_transaction_end(xsh, xth, ret)) {
 	if (ret == 0 && errno == EAGAIN) {