networkd: Add support to configure ISATAP tunnel

Let's just reuse the code of sit tunnel to create a ISATAP tunnel.
Matter of turning a flag

Please see https://elixir.bootlin.com/linux/v4.19.6/source/net/ipv6/sit.c#L208

diff --git a/man/systemd.netdev.xml b/man/systemd.netdev.xml
index f17a6a961905a81aadc794d282e7beba1cbe8d12..67ccc66dd8ed09ffd17378504c23b6140453ece9 100644 (file)
--- a/man/systemd.netdev.xml
+++ b/man/systemd.netdev.xml
@@ -924,6 +924,13 @@
           applicable to SIT tunnels.</para>
         </listitem>
       </varlistentry>
+      <varlistentry>
+        <term><varname>ISATAP=</varname></term>
+        <listitem>
+          <para>Takes a boolean. If set, configures the tunnel as Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) tunnel.
+          Only applicable to SIT tunnels. When unset, the kernel's default will be used.</para>
+        </listitem>
+      </varlistentry>
       <varlistentry>
         <term><varname>SerializeTunneledPackets=</varname></term>
         <listitem>

diff --git a/src/network/netdev/netdev-gperf.gperf b/src/network/netdev/netdev-gperf.gperf
index 49752c2d8a2e96bcd57dc61573c37b08aee636ae..fbc7a59e9e8ca3749947b14ff0fd8be20d63b232 100644 (file)
--- a/src/network/netdev/netdev-gperf.gperf
+++ b/src/network/netdev/netdev-gperf.gperf
@@ -73,6 +73,7 @@ Tunnel.Encapsulation,              config_parse_fou_encap_type,          0,
 Tunnel.IPv6RapidDeploymentPrefix,  config_parse_6rd_prefix,              0,                             0
 Tunnel.ERSPANIndex,                config_parse_uint32,                  0,                             offsetof(Tunnel, erspan_index)
 Tunnel.SerializeTunneledPackets,   config_parse_tristate,                0,                             offsetof(Tunnel, erspan_sequence)
+Tunnel.ISATAP,                     config_parse_tristate,                0,                             offsetof(Tunnel, isatap)
 FooOverUDP.Protocol,               config_parse_uint8,                   0,                             offsetof(FouTunnel, fou_protocol)
 FooOverUDP.Encapsulation,          config_parse_fou_encap_type,          0,                             offsetof(FouTunnel, fou_encap_type)
 FooOverUDP.Port,                   config_parse_ip_port,                 0,                             offsetof(FouTunnel, port)

diff --git a/src/network/netdev/tunnel.c b/src/network/netdev/tunnel.c
index 36f1fe7b03403c959d23422f9727b66010b7a704..684edddb5f5307a1ac25940097cebb7fce63e68a 100644 (file)
--- a/src/network/netdev/tunnel.c
+++ b/src/network/netdev/tunnel.c
@@ -118,6 +118,7 @@ static int netdev_sit_fill_message_create(NetDev *netdev, Link *link, sd_netlink
                 r = sd_netlink_message_append_in6_addr(m, IFLA_IPTUN_6RD_PREFIX, &t->sixrd_prefix);
                 if (r < 0)
                         return log_netdev_error_errno(netdev, r, "Could not append IFLA_IPTUN_6RD_PREFIX attribute: %m");
+
                 /* u16 is deliberate here, even though we're passing a netmask that can never be >128. The kernel is
                  * expecting to receive the prefixlen as a u16.
                  */
@@ -126,6 +127,16 @@ static int netdev_sit_fill_message_create(NetDev *netdev, Link *link, sd_netlink
                         return log_netdev_error_errno(netdev, r, "Could not append IFLA_IPTUN_6RD_PREFIXLEN attribute: %m");
         }
 
+        if (t->isatap >= 0) {
+                uint16_t flags = 0;
+
+                SET_FLAG(flags, SIT_ISATAP, t->isatap);
+
+                r = sd_netlink_message_append_u16(m, IFLA_IPTUN_FLAGS, flags);
+                if (r < 0)
+                        return log_netdev_error_errno(netdev, r, "Could not append IFLA_IPTUN_FLAGS attribute: %m");
+        }
+
         return r;
 }
 
@@ -761,6 +772,7 @@ static void sit_init(NetDev *n) {
         assert(t);
 
         t->pmtudisc = true;
+        t->isatap = -1;
 }
 
 static void vti_init(NetDev *n) {

diff --git a/src/network/netdev/tunnel.h b/src/network/netdev/tunnel.h
index 51b61637ad44a92fcf25ed848f7e583d3826a022..8f511dd1f64a90cd8e68ab4a568df925eb25bf3c 100644 (file)
--- a/src/network/netdev/tunnel.h
+++ b/src/network/netdev/tunnel.h
@@ -30,6 +30,7 @@ typedef struct Tunnel {
         int ipv6_flowlabel;
         int allow_localremote;
         int erspan_sequence;
+        int isatap;
 
         unsigned ttl;
         unsigned tos;

diff --git a/test/fuzz/fuzz-netdev-parser/directives.netdev b/test/fuzz/fuzz-netdev-parser/directives.netdev
index 19226df80621846226a4889e684b0b405120981b..5a8d41eb68385e2949940b80752062eb4207e492 100644 (file)
--- a/test/fuzz/fuzz-netdev-parser/directives.netdev
+++ b/test/fuzz/fuzz-netdev-parser/directives.netdev
@@ -76,6 +76,7 @@ FOUSourcePort=
 IPv6RapidDeploymentPrefix=
 ERSPANIndex=
 SerializeTunneledPackets=
+ISATAP=
 [VXLAN]
 UDP6ZeroChecksumRx=
 ARPProxy=