From 1513e8162aee3202b99f26fa6c734766b5658db9 Mon Sep 17 00:00:00 2001
From: Ying Lv <lvying6@huawei.com>
Date: Mon, 2 Mar 2020 18:08:54 +0800

---
 ip/ip_common.h |  2 ++
 ip/ipaddress.c |  2 +-
 ip/ipnetns.c   | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/ip/ip_common.h b/ip/ip_common.h
index 879287e..6d10e53 100644
--- a/ip/ip_common.h
+++ b/ip/ip_common.h
@@ -90,6 +90,8 @@ int iplink_ifla_xstats(int argc, char **argv);
 int ip_link_list(req_filter_fn_t filter_fn, struct nlmsg_chain *linfo);
 void free_nlmsg_chain(struct nlmsg_chain *info);
 
+int store_nlmsg(struct nlmsghdr *n, void *arg);
+
 static inline int rtm_get_table(struct rtmsg *r, struct rtattr **tb)
 {
 	__u32 table = r->rtm_table;
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index bc8f5ba..cb38db3 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -1519,7 +1519,7 @@ static int print_selected_addrinfo(struct ifinfomsg *ifi,
 }
 
 
-static int store_nlmsg(struct nlmsghdr *n, void *arg)
+int store_nlmsg(struct nlmsghdr *n, void *arg)
 {
 	struct nlmsg_chain *lchain = (struct nlmsg_chain *)arg;
 	struct nlmsg_list *h;
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index fedc3db..e36ca51 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -754,6 +754,51 @@ static int netns_identify(int argc, char **argv)
 	return rc;
 }
 
+static int check_netns_numbers(char *name) {
+	char net_path[MAXPATHLEN];
+	struct rtnl_handle rth = { .fd = -1 };
+	struct nlmsg_chain linfo = { NULL, NULL};
+	struct nlmsg_list *l;
+	int count = 0;
+	int netns;
+
+	snprintf(net_path, sizeof(net_path), "%s/%s", NETNS_RUN_DIR, name);
+	netns = open(net_path, O_RDONLY | O_CLOEXEC);
+	if (netns < 0) {
+		fprintf(stderr, "Cannot open network namespace \"%s\": %s\n",
+				name, strerror(errno));
+		exit(1);
+	}
+
+	if (setns(netns, CLONE_NEWNET) < 0) {
+		fprintf(stderr, "seting the network namespace \"%s\" failed: %s\n",
+				name, strerror(errno));
+		exit(1);
+	}
+
+	if (rtnl_open(&rth, 0) < 0)
+		exit(1);
+
+	if (rtnl_linkdump_req(&rth, AF_PACKET) < 0) {
+		fprintf(stderr, "Cannot send dump request");
+		exit(1);
+	}
+
+	if (rtnl_dump_filter(&rth, store_nlmsg, &linfo) < 0) {
+		fprintf(stderr, "Dump terminated\n");
+		exit(1);
+	}
+
+	for (l = linfo.head; l; l = l->next) {
+		count++;
+	}
+	free_nlmsg_chain(&linfo);
+
+	rtnl_close(&rth);
+	close(netns);
+	return count;
+}
+
 static int on_netns_del(char *nsname, void *arg)
 {
 	char netns_path[PATH_MAX];
@@ -775,6 +820,12 @@ static int netns_delete(int argc, char **argv)
 		return -1;
 	}
 
+	if (check_netns_numbers(argv[0]) > 1) {
+		fprintf(stderr, "Cannot delete network namespace, there are some NICs"
+				" in %s namespace\n", argv[0]);
+		return -1;
+	}
+
 	if (do_all)
 		return netns_foreach(on_netns_del, NULL);
 
-- 
2.19.1