[PATCH iproute2 2/2] iplink: enable to specify a name for the link-netns

[Nicolas Dichtel <nicolas.dichtel@6wind.com>]

The 'link-netnsid' argument needs a number. Add 'link-netns' when the user
wants to use the iproute2 netns name instead of the nsid.

Example:
ip link add ipip1 link-netns foo type ipip remote 10.16.0.121 local 10.16.0.249

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
 ip/ip_common.h |  2 ++
 ip/iplink.c    | 18 ++++++++++++++++--
 ip/ipnetns.c   |  8 ++++++--
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/ip/ip_common.h b/ip/ip_common.h
index 794478c546cd..4d3227cbc389 100644
--- a/ip/ip_common.h
+++ b/ip/ip_common.h
@@ -61,6 +61,8 @@ void netns_nsid_socket_init(void);
 int print_nsid(const struct sockaddr_nl *who,
 	       struct nlmsghdr *n, void *arg);
 char *get_name_from_nsid(int nsid);
+int get_netnsid_from_name(const char *name);
+int set_netnsid_from_name(const char *name, int nsid);
 int do_ipaddr(int argc, char **argv);
 int do_ipaddrlabel(int argc, char **argv);
 int do_iproute(int argc, char **argv);
diff --git a/ip/iplink.c b/ip/iplink.c
index 9ff5f692a1d4..e4d4da96aedb 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -85,7 +85,7 @@ void iplink_usage(void)
 		"	                  [ broadcast LLADDR ]\n"
 		"	                  [ mtu MTU ]\n"
 		"	                  [ netns { PID | NAME } ]\n"
-		"	                  [ link-netnsid ID ]\n"
+		"	                  [ link-netns NAME | link-netnsid ID ]\n"
 		"			  [ alias NAME ]\n"
 		"	                  [ vf NUM [ mac LLADDR ]\n"
 		"				   [ vlan VLANID [ qos VLAN-QOS ] [ proto VLAN-PROTO ] ]\n"
@@ -865,10 +865,24 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
 				 IFLA_INET6_ADDR_GEN_MODE, mode);
 			addattr_nest_end(&req->n, afs6);
 			addattr_nest_end(&req->n, afs);
+		} else if (matches(*argv, "link-netns") == 0) {
+			NEXT_ARG();
+			if (link_netnsid != -1)
+				duparg("link-netns/link-netnsid", *argv);
+			link_netnsid = get_netnsid_from_name(*argv);
+			/* No nsid? Try to assign one. */
+			if (link_netnsid < 0)
+				set_netnsid_from_name(*argv, -1);
+			link_netnsid = get_netnsid_from_name(*argv);
+			if (link_netnsid < 0)
+				invarg("Invalid \"link-netns\" value\n",
+				       *argv);
+			addattr32(&req->n, sizeof(*req), IFLA_LINK_NETNSID,
+				  link_netnsid);
 		} else if (matches(*argv, "link-netnsid") == 0) {
 			NEXT_ARG();
 			if (link_netnsid != -1)
-				duparg("link-netnsid", *argv);
+				duparg("link-netns/link-netnsid", *argv);
 			if (get_integer(&link_netnsid, *argv, 0))
 				invarg("Invalid \"link-netnsid\" value\n",
 				       *argv);
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index a4f5b02427e7..fb1daade366b 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -91,7 +91,7 @@ static int ipnetns_have_nsid(void)
 	return have_rtnl_getnsid;
 }
 
-static int get_netnsid_from_name(const char *name)
+int get_netnsid_from_name(const char *name)
 {
 	struct {
 		struct nlmsghdr n;
@@ -108,6 +108,8 @@ static int get_netnsid_from_name(const char *name)
 	struct rtgenmsg *rthdr;
 	int len, fd;
 
+	netns_nsid_socket_init();
+
 	fd = netns_get_fd(name);
 	if (fd < 0)
 		return fd;
@@ -701,7 +703,7 @@ out_delete:
 	return -1;
 }
 
-static int set_netnsid_from_name(const char *name, int nsid)
+int set_netnsid_from_name(const char *name, int nsid)
 {
 	struct {
 		struct nlmsghdr n;
@@ -715,6 +717,8 @@ static int set_netnsid_from_name(const char *name, int nsid)
 	};
 	int fd, err = 0;
 
+	netns_nsid_socket_init();
+
 	fd = netns_get_fd(name);
 	if (fd < 0)
 		return fd;
-- 
2.15.1