From 0c74068f5643b87db779bb92c73679b257e03a9c Mon Sep 17 00:00:00 2001
From: Stefano Brivio <sbrivio@redhat.com>
Date: Thu, 15 Aug 2024 00:09:43 +0200
Subject: [PATCH] netlink, pasta: Turn nl_link_up() into a generic function to
 set link flags

In the next patches, we'll reuse it to set flags other than IFF_UP.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 netlink.c | 11 +++++++----
 netlink.h |  3 ++-
 pasta.c   |  4 ++--
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/netlink.c b/netlink.c
index e33765e..873e6c7 100644
--- a/netlink.c
+++ b/netlink.c
@@ -968,13 +968,16 @@ int nl_link_set_mtu(int s, unsigned int ifi, int mtu)
 }
 
 /**
- * nl_link_up() - Bring link up
+ * nl_link_set_flags() - Set link flags
  * @s:		Netlink socket
  * @ifi:	Interface index
+ * @set:	Device flags to set
+ * @change:	Mask of device flag changes
  *
  * Return: 0 on success, negative error code on failure
  */
-int nl_link_up(int s, unsigned int ifi)
+int nl_link_set_flags(int s, unsigned int ifi,
+		      unsigned int set, unsigned int change)
 {
 	struct req_t {
 		struct nlmsghdr nlh;
@@ -982,8 +985,8 @@ int nl_link_up(int s, unsigned int ifi)
 	} req = {
 		.ifm.ifi_family	  = AF_UNSPEC,
 		.ifm.ifi_index	  = ifi,
-		.ifm.ifi_flags	  = IFF_UP,
-		.ifm.ifi_change	  = IFF_UP,
+		.ifm.ifi_flags	  = set,
+		.ifm.ifi_change	  = change,
 	};
 
 	return nl_do(s, &req, RTM_NEWLINK, 0, sizeof(req));
diff --git a/netlink.h b/netlink.h
index 87d27ae..178f8ae 100644
--- a/netlink.h
+++ b/netlink.h
@@ -24,6 +24,7 @@ int nl_addr_dup(int s_src, unsigned int ifi_src,
 int nl_link_get_mac(int s, unsigned int ifi, void *mac);
 int nl_link_set_mac(int s, unsigned int ifi, const void *mac);
 int nl_link_set_mtu(int s, unsigned int ifi, int mtu);
-int nl_link_up(int s, unsigned int ifi);
+int nl_link_set_flags(int s, unsigned int ifi,
+		      unsigned int set, unsigned int change);
 
 #endif /* NETLINK_H */
diff --git a/pasta.c b/pasta.c
index 3a0652e..96545b1 100644
--- a/pasta.c
+++ b/pasta.c
@@ -288,7 +288,7 @@ void pasta_ns_conf(struct ctx *c)
 {
 	int rc = 0;
 
-	rc = nl_link_up(nl_sock_ns, 1 /* lo */);
+	rc = nl_link_set_flags(nl_sock_ns, 1 /* lo */, IFF_UP, IFF_UP);
 	if (rc < 0)
 		die("Couldn't bring up loopback interface in namespace: %s",
 		    strerror(-rc));
@@ -306,7 +306,7 @@ void pasta_ns_conf(struct ctx *c)
 		if (c->mtu != -1)
 			nl_link_set_mtu(nl_sock_ns, c->pasta_ifi, c->mtu);
 
-		nl_link_up(nl_sock_ns, c->pasta_ifi);
+		nl_link_set_flags(nl_sock_ns, c->pasta_ifi, IFF_UP, IFF_UP);
 
 		if (c->ifi4) {
 			if (c->ip4.no_copy_addrs) {