From cbee8106e38f9ffa130c7bf8be325f7f203da67a Mon Sep 17 00:00:00 2001
From: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Wed, 10 Jul 2013 23:30:29 -0500
Subject: [PATCH] lxcapi_create: fix template handling

1. If no template is passed in, then do not try to execute it.  The user
just wanted to write the configuration.

2. If template is passed in as a full path, then use that instead of
constructing '$templatedir/lxc-$template'.

Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
---
 src/lxc/lxccontainer.c | 64 ++++++++++++++++++++++++++++--------------
 1 file changed, 43 insertions(+), 21 deletions(-)

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 596c189a2..6326eb074 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -646,17 +646,6 @@ static bool lxcapi_stop(struct lxc_container *c)
 	return ret == 0;
 }
 
-static bool valid_template(char *t)
-{
-	struct stat statbuf;
-	int statret;
-
-	statret = stat(t, &statbuf);
-	if (statret == 0)
-		return true;
-	return false;
-}
-
 /*
  * create the standard expected container dir
  */
@@ -715,6 +704,46 @@ static struct bdev *do_bdev_create(struct lxc_container *c, const char *type,
 	return bdev;
 }
 
+/*
+ * Given the '-t' template option to lxc-create, figure out what to
+ * do.  If the template is a full executable path, use that.  If it
+ * is something like 'sshd', then return $templatepath/lxc-sshd.  If
+ * no template was passed in, return NULL  (this is ok).
+ * On error return (char *) -1.
+ */
+char *get_template_path(const char *t)
+{
+	int ret, len;
+	char *tpath;
+
+	if (!t)
+		return NULL;
+
+	if (t[0] == '/' && access(t, X_OK) == 0) {
+		tpath = strdup(t);
+		if (!tpath)
+			return (char *) -1;
+		return tpath;
+	}
+
+	len = strlen(LXCTEMPLATEDIR) + strlen(t) + strlen("/lxc-") + 1;
+	tpath = malloc(len);
+	if (!tpath)
+		return (char *) -1;
+	ret = snprintf(tpath, len, "%s/lxc-%s", LXCTEMPLATEDIR, t);
+	if (ret < 0 || ret >= len) {
+		free(tpath);
+		return (char *) -1;
+	}
+	if (access(tpath, X_OK) < 0) {
+		SYSERROR("bad template: %s\n", t);
+		free(tpath);
+		return (char *) -1;
+	}
+
+	return tpath;
+}
+
 static char *lxcbasename(char *path)
 {
 	char *p = path + strlen(path) - 1;
@@ -854,20 +883,13 @@ static bool lxcapi_create(struct lxc_container *c, const char *t,
 {
 	bool bret = false;
 	pid_t pid;
-	char *tpath = NULL;
-	int partial_fd, ret, len;
+	char *tpath;
+	int partial_fd;
 
 	if (!c)
 		return false;
 
-	len = strlen(LXCTEMPLATEDIR) + strlen(t) + strlen("/lxc-") + 1;
-	tpath = malloc(len);
-	if (!tpath)
-		return false;
-	ret = snprintf(tpath, len, "%s/lxc-%s", LXCTEMPLATEDIR, t);
-	if (ret < 0 || ret >= len)
-		goto out;
-	if (!valid_template(tpath)) {
+	if ((tpath = get_template_path(t)) < 0) {
 		ERROR("bad template: %s\n", t);
 		goto out;
 	}