[git commit] ip: added support for setting netns on devices

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=c28313bb176639e1e4b11a63f6452baebf69f28e
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
set_netns                                              -     130    +130
do_iplink                                           1252    1315     +63
.rodata                                           104173  104179      +6
packed_usage                                       34020   33993     -27
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 199/-27)           Total: 172 bytes

Signed-off-by: Nicholas Niro <blowfist at xroutine.net>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 networking/ip.c                |  2 +-
 networking/libiproute/iplink.c | 35 +++++++++++++++++++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/networking/ip.c b/networking/ip.c
index 85b1ba080..7c3208699 100644
--- a/networking/ip.c
+++ b/networking/ip.c
@@ -152,7 +152,7 @@
 //usage:#define iplink_trivial_usage
 //usage:       /*Usage:iplink*/"set IFACE [up|down] [arp on|off] [multicast on|off]\n"
 //usage:       "	[promisc on|off] [mtu NUM] [name NAME] [qlen NUM] [address MAC]\n"
-//usage:       "	[master IFACE | nomaster]"
+//usage:       "	[master IFACE | nomaster] [netns PID]"
 // * short help shows only "set" command, long help continues (with just one "\n")
 // * and shows all other commands:
 //usage:#define iplink_full_usage "\n"
diff --git a/networking/libiproute/iplink.c b/networking/libiproute/iplink.c
index 1a1064bdc..68d199044 100644
--- a/networking/libiproute/iplink.c
+++ b/networking/libiproute/iplink.c
@@ -152,6 +152,30 @@ static void set_master(char *dev, int master)
 		xfunc_die();
 }
 
+/* Exits on error */
+static void set_netns(char *dev, int netns)
+{
+	struct rtnl_handle rth;
+	struct {
+		struct nlmsghdr  n;
+		struct ifinfomsg i;
+		char             buf[1024];
+	} req;
+
+	memset(&req, 0, sizeof(req));
+	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	req.n.nlmsg_flags = NLM_F_REQUEST;
+	req.n.nlmsg_type = RTM_NEWLINK;
+	req.i.ifi_family = preferred_family;
+
+	xrtnl_open(&rth);
+	req.i.ifi_index = xll_name_to_index(dev);
+	//printf("netns %i for %i\n", netns, req.i.ifi_index);
+	addattr_l(&req.n, sizeof(req), IFLA_NET_NS_PID, &netns, 4);
+	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
+		xfunc_die();
+}
+
 /* Exits on error */
 static int get_address(char *dev, int *htype)
 {
@@ -226,6 +250,7 @@ static int do_set(char **argv)
 	int qlen = -1;
 	int mtu = -1;
 	int master = -1;
+	int netns = -1;
 	char *newaddr = NULL;
 	char *newbrd = NULL;
 	struct ifreq ifr0, ifr1;
@@ -234,11 +259,11 @@ static int do_set(char **argv)
 	/* If you add stuff here, update iplink_full_usage */
 	static const char keywords[] ALIGN1 =
 		"up\0""down\0""name\0""mtu\0""qlen\0""multicast\0"
-		"arp\0""promisc\0""address\0"
+		"arp\0""promisc\0""address\0""netns\0"
 		"master\0""nomaster\0"
 		"dev\0" /* must be last */;
 	enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_qlen, ARG_multicast,
-		ARG_arp, ARG_promisc, ARG_addr,
+		ARG_arp, ARG_promisc, ARG_addr, ARG_netns,
 		ARG_master, ARG_nomaster,
 		ARG_dev };
 	enum { PARM_on = 0, PARM_off };
@@ -276,6 +301,9 @@ static int do_set(char **argv)
 			master = xll_name_to_index(*argv);
 		} else if (key == ARG_nomaster) {
 			master = 0;
+		} else if (key == ARG_netns) {
+			NEXT_ARG();
+			netns = get_unsigned(*argv, "netns");
 		} else if (key >= ARG_dev) {
 			/* ^^^^^^ ">=" here results in "dev IFACE" treated as default */
 			if (key == ARG_dev) {
@@ -463,6 +491,9 @@ static int do_set(char **argv)
 	if (master != -1) {
 		set_master(dev, master);
 	}
+	if (netns != -1) {
+		set_netns(dev, netns);
+	}
 	if (mask)
 		do_chflags(dev, flags, mask);
 	return 0;