executor: fix setup of xfrm device

XFRM device creation will fail w/o IFLA_XFRM_IF_ID attribute:
https://elixir.bootlin.com/linux/v6.0-rc4/source/net/xfrm/xfrm_interface.c#L648
Add this attribute.

This ID is also present in descriptions in at least 2 places.
In one we got it wrong, it's not ifindex (easy to confuse because of the name).
Fix it as well.

1 files changed, 29 insertions, 12 deletions

diff --git a/executor/common_linux.h b/executor/common_linux.h
index bf8db5502..6ab9265d1 100644
--- a/executor/common_linux.h
+++ b/executor/common_linux.h
@@ -283,10 +283,12 @@ static int netlink_next_msg(struct nlmsg* nlmsg, unsigned int offset,
 
 #if SYZ_EXECUTOR || SYZ_NET_DEVICES || SYZ_802154
 static void netlink_add_device_impl(struct nlmsg* nlmsg, const char* type,
-				    const char* name)
+				    const char* name, bool up)
 {
 	struct ifinfomsg hdr;
 	memset(&hdr, 0, sizeof(hdr));
+	if (up)
+		hdr.ifi_flags = hdr.ifi_change = IFF_UP;
 	netlink_init(nlmsg, RTM_NEWLINK, NLM_F_EXCL | NLM_F_CREATE, &hdr, sizeof(hdr));
 	if (name)
 		netlink_attr(nlmsg, IFLA_IFNAME, name, strlen(name));
@@ -299,7 +301,7 @@ static void netlink_add_device_impl(struct nlmsg* nlmsg, const char* type,
 static void netlink_add_device(struct nlmsg* nlmsg, int sock, const char* type,
 			       const char* name)
 {
-	netlink_add_device_impl(nlmsg, type, name);
+	netlink_add_device_impl(nlmsg, type, name, false);
 	netlink_done(nlmsg);
 	int err = netlink_send(nlmsg, sock);
 	if (err < 0) {
@@ -310,7 +312,7 @@ static void netlink_add_device(struct nlmsg* nlmsg, int sock, const char* type,
 static void netlink_add_veth(struct nlmsg* nlmsg, int sock, const char* name,
 			     const char* peer)
 {
-	netlink_add_device_impl(nlmsg, "veth", name);
+	netlink_add_device_impl(nlmsg, "veth", name, false);
 	netlink_nest(nlmsg, IFLA_INFO_DATA);
 	netlink_nest(nlmsg, VETH_INFO_PEER);
 	nlmsg->pos += sizeof(struct ifinfomsg);
@@ -324,10 +326,24 @@ static void netlink_add_veth(struct nlmsg* nlmsg, int sock, const char* name,
 	}
 }
 
+static void netlink_add_xfrm(struct nlmsg* nlmsg, int sock, const char* name)
+{
+	netlink_add_device_impl(nlmsg, "xfrm", name, true);
+	netlink_nest(nlmsg, IFLA_INFO_DATA);
+	int if_id = 1;
+	netlink_attr(nlmsg, IFLA_XFRM_IF_ID, &if_id, sizeof(if_id));
+	netlink_done(nlmsg);
+	netlink_done(nlmsg);
+	int err = netlink_send(nlmsg, sock);
+	if (err < 0) {
+		debug("netlink: adding device %s type xfrm if_id %d: %s\n", name, if_id, strerror(errno));
+	}
+}
+
 static void netlink_add_hsr(struct nlmsg* nlmsg, int sock, const char* name,
 			    const char* slave1, const char* slave2)
 {
-	netlink_add_device_impl(nlmsg, "hsr", name);
+	netlink_add_device_impl(nlmsg, "hsr", name, false);
 	netlink_nest(nlmsg, IFLA_INFO_DATA);
 	int ifindex1 = if_nametoindex(slave1);
 	netlink_attr(nlmsg, IFLA_HSR_SLAVE1, &ifindex1, sizeof(ifindex1));
@@ -337,13 +353,13 @@ static void netlink_add_hsr(struct nlmsg* nlmsg, int sock, const char* name,
 	netlink_done(nlmsg);
 	int err = netlink_send(nlmsg, sock);
 	if (err < 0) {
-		debug("netlink: adding device %s type hsr slave1 %s slave2 %s: %s\n", name, slave1, slave2, strerror(err));
+		debug("netlink: adding device %s type hsr slave1 %s slave2 %s: %s\n", name, slave1, slave2, strerror(errno));
 	}
 }
 
 static void netlink_add_linked(struct nlmsg* nlmsg, int sock, const char* type, const char* name, const char* link)
 {
-	netlink_add_device_impl(nlmsg, type, name);
+	netlink_add_device_impl(nlmsg, type, name, false);
 	netlink_done(nlmsg);
 	int ifindex = if_nametoindex(link);
 	netlink_attr(nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex));
@@ -355,7 +371,7 @@ static void netlink_add_linked(struct nlmsg* nlmsg, int sock, const char* type,
 
 static void netlink_add_vlan(struct nlmsg* nlmsg, int sock, const char* name, const char* link, uint16 id, uint16 proto)
 {
-	netlink_add_device_impl(nlmsg, "vlan", name);
+	netlink_add_device_impl(nlmsg, "vlan", name, false);
 	netlink_nest(nlmsg, IFLA_INFO_DATA);
 	netlink_attr(nlmsg, IFLA_VLAN_ID, &id, sizeof(id));
 	netlink_attr(nlmsg, IFLA_VLAN_PROTOCOL, &proto, sizeof(proto));
@@ -371,7 +387,7 @@ static void netlink_add_vlan(struct nlmsg* nlmsg, int sock, const char* name, co
 
 static void netlink_add_macvlan(struct nlmsg* nlmsg, int sock, const char* name, const char* link)
 {
-	netlink_add_device_impl(nlmsg, "macvlan", name);
+	netlink_add_device_impl(nlmsg, "macvlan", name, false);
 	netlink_nest(nlmsg, IFLA_INFO_DATA);
 	uint32 mode = MACVLAN_MODE_BRIDGE;
 	netlink_attr(nlmsg, IFLA_MACVLAN_MODE, &mode, sizeof(mode));
@@ -387,7 +403,7 @@ static void netlink_add_macvlan(struct nlmsg* nlmsg, int sock, const char* name,
 
 static void netlink_add_geneve(struct nlmsg* nlmsg, int sock, const char* name, uint32 vni, struct in_addr* addr4, struct in6_addr* addr6)
 {
-	netlink_add_device_impl(nlmsg, "geneve", name);
+	netlink_add_device_impl(nlmsg, "geneve", name, false);
 	netlink_nest(nlmsg, IFLA_INFO_DATA);
 	netlink_attr(nlmsg, IFLA_GENEVE_ID, &vni, sizeof(vni));
 	if (addr4)
@@ -409,7 +425,7 @@ static void netlink_add_geneve(struct nlmsg* nlmsg, int sock, const char* name,
 
 static void netlink_add_ipvlan(struct nlmsg* nlmsg, int sock, const char* name, const char* link, uint16 mode, uint16 flags)
 {
-	netlink_add_device_impl(nlmsg, "ipvlan", name);
+	netlink_add_device_impl(nlmsg, "ipvlan", name, false);
 	netlink_nest(nlmsg, IFLA_INFO_DATA);
 	netlink_attr(nlmsg, IFLA_IPVLAN_MODE, &mode, sizeof(mode));
 	netlink_attr(nlmsg, IFLA_IPVLAN_FLAGS, &flags, sizeof(flags));
@@ -1371,7 +1387,6 @@ static void initialize_netdevices(void)
 	    {"netdevsim", netdevsim},
 	    // This adds connected veth0 and veth1 devices.
 	    {"veth", 0},
-	    {"xfrm", "xfrm0"},
 	    {"wireguard", "wg0"},
 	    {"wireguard", "wg1"},
 	    {"wireguard", "wg2"},
@@ -1465,6 +1480,8 @@ static void initialize_netdevices(void)
 		netlink_device_change(&nlmsg, sock, slave0, false, master, 0, 0, NULL);
 		netlink_device_change(&nlmsg, sock, slave1, false, master, 0, 0, NULL);
 	}
+	netlink_add_xfrm(&nlmsg, sock, "xfrm0");
+
 	// bond/team_slave_* will set up automatically when set their master.
 	// But bridge_slave_* need to set up manually.
 	netlink_device_change(&nlmsg, sock, "bridge_slave_0", true, 0, 0, 0, NULL);
@@ -4841,7 +4858,7 @@ static void setup_802154()
 		}
 		netlink_device_change(&nlmsg, sock_route, devname, true, 0, &hwaddr, sizeof(hwaddr), 0);
 		if (i == 0) {
-			netlink_add_device_impl(&nlmsg, "lowpan", "lowpan0");
+			netlink_add_device_impl(&nlmsg, "lowpan", "lowpan0", false);
 			netlink_done(&nlmsg);
 			netlink_attr(&nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex));
 			int err = netlink_send(&nlmsg, sock_route);