Move default root set to network-hypervisor, add a priority level to roots.

zerotier-network-hypervisor/default-rootset/make-root-set.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+# This is for internal use by ZeroTier, but obviously users can repurpose it to make their own.
+
+# Usage: make-root-set.sh <identity.secret> [<...>]
+
+for i in $*; do
+	echo $i
+	../../zerotier-system-service/target/debug/zerotier-system-service rootset sign root.zerotier.com.json $i >tmp.json
+	mv -f tmp.json root.zerotier.com.json
+	../../zerotier-system-service/target/debug/zerotier-system-service rootset marshal root.zerotier.com.json >root.zerotier.com.bin
+done
+
+cat root.zerotier.com.json

zerotier-network-hypervisor/default-rootset/root.zerotier.com.json

@@ -0,0 +1,25 @@
+{
+  "name": "root.zerotier.com",
+  "revision": 1,
+  "members": [ {
+      "identity": "62f865ae71:0:e2076c57de870e6288d7d5e7404408b1545efca37d67f77b87e9e54168c25d3ef1a9abf2905ea5e785c01dff23887ad4232d95c7a8fd2c27111a72bd159322dc",
+      "endpoints": [ "udp:50.7.252.138/9993", "udp:2001:49f0:d0db:2::2/9993" ],
+      "signature": [ 1, 250, 55, 178, 250, 221, 13, 136, 125, 246, 209, 222, 43, 154, 3, 87, 224, 202, 86, 154, 217, 132, 141, 77, 246, 233, 118, 35, 112, 37, 58, 226, 104, 232, 33, 180, 29, 159, 20, 100, 217, 129, 242, 16, 247, 253, 70, 245, 59, 22, 126, 148, 52, 7, 231, 5, 230, 252, 35, 204, 22, 12, 85, 122, 10 ],
+      "priority": 0
+    }, {
+      "identity": "778cde7190:0:3f6681a99e5ad1895e9fba33e6212d4454e168bcec7112101bf000956ed8e92e42892cb6f2ec410881a84ab19da50e1287ba3d926c3a1f755cccf299a1207055",
+      "endpoints": [ "udp:103.195.103.66/9993", "udp:2605:9880:400:c3:254:f2bc:a1f7:19/9993" ],
+      "signature": [ 1, 115, 251, 30, 185, 137, 187, 219, 80, 35, 19, 117, 38, 241, 200, 137, 205, 208, 73, 54, 30, 158, 150, 64, 232, 214, 248, 54, 26, 180, 29, 68, 87, 34, 102, 251, 199, 158, 215, 199, 77, 8, 128, 93, 166, 199, 39, 139, 143, 20, 180, 29, 145, 232, 90, 181, 75, 237, 175, 238, 2, 124, 18, 124, 4 ],
+      "priority": 0
+    }, {
+      "identity": "cafe04eba9:0:6c6a9d1dea55c1616bfe2a2b8f0ff9a8cacaf70374fb1f39e3bef81cbfebef17b7228268a0a2a29d3488c752565c6c965cbd6506ec24397cc8a5d9d15285a87f",
+      "endpoints": [ "udp:84.17.53.155/9993", "udp:2a02:6ea0:d405::9993/9993" ],
+      "signature": [ 1, 51, 245, 92, 49, 30, 240, 161, 49, 14, 233, 231, 237, 169, 55, 1, 171, 91, 121, 3, 157, 139, 135, 177, 212, 199, 26, 188, 98, 130, 138, 39, 193, 45, 190, 243, 146, 15, 234, 220, 203, 154, 39, 230, 88, 152, 164, 74, 44, 136, 125, 207, 23, 31, 112, 52, 16, 116, 179, 99, 93, 133, 133, 189, 6 ],
+      "priority": 0
+    }, {
+      "identity": "cafe9efeb9:0:ccdef76bc7b97ded904eabc5df09886d9c1514a610036cb9139cc214001a2958978efcec15712dd3948c6e6b3a8e893df01ff493d1f8d9806a860c5420571bf0",
+      "endpoints": [ "udp:104.194.8.134/9993", "udp:2605:9880:200:1200:30:571:e34:51/9993" ],
+      "signature": [ 1, 237, 145, 250, 221, 80, 44, 48, 158, 74, 198, 149, 192, 96, 220, 223, 232, 141, 163, 254, 173, 190, 7, 16, 67, 234, 182, 183, 16, 36, 154, 40, 141, 98, 18, 253, 57, 186, 222, 71, 223, 247, 43, 131, 203, 38, 79, 36, 43, 52, 130, 80, 218, 188, 3, 175, 221, 108, 218, 139, 248, 37, 228, 112, 5 ],
+      "priority": 0
+    } ]
+}

zerotier-network-hypervisor/src/util/buffer.rs

@@ -497,6 +497,20 @@ impl<const L: usize> AsMut<[u8]> for Buffer<L> {
     }
 }
 
+impl<const L: usize> From<[u8; L]> for Buffer<L> {
+    #[inline(always)]
+    fn from(a: [u8; L]) -> Self {
+        Self(L, a)
+    }
+}
+
+impl<const L: usize> From<&[u8; L]> for Buffer<L> {
+    #[inline(always)]
+    fn from(a: &[u8; L]) -> Self {
+        Self(L, a.clone())
+    }
+}
+
 pub struct PooledBufferFactory<const L: usize>;
 
 impl<const L: usize> PooledBufferFactory<L> {

zerotier-network-hypervisor/src/vl1/rootset.rs

@@ -18,34 +18,44 @@ use crate::vl1::Endpoint;
 use serde::{Deserialize, Serialize};
 
 /// Description of a member of a root cluster.
+///
+/// Natural sort order is in order of identity address.
 #[derive(Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Root {
-    /// Full identity of this node.
+    /// Identity of this node (not including secret).
     pub identity: Identity,
 
-    /// Endpoints for this root or None if this is a former member attesting to an update that removes it.
+    /// Endpoints for this root or None if this is a disabled entry.
+    ///
+    /// Disabled entries typically exist when a former member is needed to sign a new revision to
+    /// achieve N-1 quorum and issue an update.
     pub endpoints: Option<BTreeSet<Endpoint>>,
 
     /// Signature of entire root set by this identity.
+    ///
+    /// This is populated by the sign() method when the completed root set is signed by each member.
+    /// All member roots must sign.
     #[serde(default)]
     pub signature: Vec<u8>,
 
-    /// Flags field (currently unused).
+    /// Priority (higher number is lower priority, 0 is default).
+    ///
+    /// Lower priority roots are only used if NO roots of a higher priority can be reached (in any root set).
     #[serde(default)]
-    pub flags: u64,
+    pub priority: u8,
 }
 
 impl PartialOrd for Root {
     #[inline(always)]
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        self.identity.partial_cmp(&other.identity)
+        self.identity.address.partial_cmp(&other.identity.address)
     }
 }
 
 impl Ord for Root {
     #[inline(always)]
     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.identity.cmp(&other.identity)
+        self.identity.address.cmp(&other.identity.address)
     }
 }
 
@@ -67,7 +77,8 @@ pub struct RootSet {
     pub revision: u64,
 
     /// A set of Root nodes that are current or immediately former members of this cluster.
-    /// This will always be sorted by member identity.
+    ///
+    /// This will always be sorted by member identity address. Duplicate addresses are not allowed.
     pub members: Vec<Root>,
 }
 
@@ -76,6 +87,12 @@ impl RootSet {
         Self { name, revision, members: Vec::new() }
     }
 
+    /// Get the ZeroTier default root set, which contains roots run by ZeroTier Inc.
+    pub fn zerotier_default() -> Self {
+        let mut cursor = 0;
+        Self::unmarshal(&Buffer::from(include_bytes!("../../default-rootset/root.zerotier.com.json")), &mut cursor).unwrap()
+    }
+
     fn marshal_internal<const BL: usize>(&self, buf: &mut Buffer<BL>, include_signatures: bool) -> std::io::Result<()> {
         buf.append_u8(0)?; // version byte for future use
         buf.append_varint(self.name.as_bytes().len() as u64)?;
@@ -97,7 +114,8 @@ impl RootSet {
                 buf.append_varint(m.signature.len() as u64)?;
                 buf.append_bytes(m.signature.as_slice())?;
             }
-            buf.append_varint(m.flags)?;
+            buf.append_varint(0)?; // flags, currently always 0
+            buf.append_u8(m.priority)?;
             buf.append_varint(0)?; // size of additional fields for future use
         }
         buf.append_varint(0)?; // size of additional fields for future use
@@ -127,9 +145,9 @@ impl RootSet {
         return true;
     }
 
-    /// Add a member to this definition, replacing any current entry for this identity.
+    /// Add a member to this definition, replacing any current entry with this address.
-    pub fn add<'a, I: Iterator<Item = &'a Endpoint>>(&mut self, member_identity: &Identity, endpoints: Option<I>) {
+    pub fn add<'a, I: Iterator<Item = &'a Endpoint>>(&mut self, member_identity: &Identity, endpoints: Option<I>, priority: u8) {
-        self.members.retain(|m| !m.identity.eq(member_identity));
+        self.members.retain(|m| m.identity.address != member_identity.address);
         let _ = self.members.push(Root {
             identity: member_identity.clone_without_secret(),
             endpoints: endpoints.map(|endpoints| {
@@ -140,7 +158,7 @@ impl RootSet {
                 tmp
             }),
             signature: Vec::new(),
-            flags: 0,
+            priority,
         });
         self.members.sort();
     }
@@ -162,7 +180,7 @@ impl RootSet {
                 identity: unsigned_entry.identity,
                 endpoints: unsigned_entry.endpoints,
                 signature: signature.unwrap(),
-                flags: unsigned_entry.flags,
+                priority: unsigned_entry.priority,
             });
             self.members.sort();
             return true;
@@ -178,7 +196,7 @@ impl RootSet {
     /// root nodes can replace one member if three cluster members sign the update, but to
     /// remove two at a time one of the exiting members would have to sign. This is done by
     /// adding it with None as its address list, making it disabled. Disabled members function
-    /// only as signers (witnesses).
+    /// only as signers (witnesses) and only if they were enabled previously.
     ///
     /// There is one edge case though. If a cluster definition has only one member, that one
     /// member must sign the next update. N-1 is not permitted to be less than one. If that was
@@ -237,7 +255,7 @@ impl Marshalable for RootSet {
                 identity: Identity::unmarshal(buf, cursor)?,
                 endpoints: None,
                 signature: Vec::new(),
-                flags: 0,
+                priority: 0,
             };
 
             let endpoint_count = buf.read_varint(cursor)?;
@@ -252,7 +270,8 @@ impl Marshalable for RootSet {
             let signature_size = buf.read_varint(cursor)?;
             let _ = m.signature.write_all(buf.read_bytes(signature_size as usize, cursor)?);
 
-            m.flags = buf.read_varint(cursor)?;
+            let _ = buf.read_varint(cursor)?; // flags, currently unused
+            m.priority = buf.read_u8(cursor)?;
 
             *cursor += buf.read_varint(cursor)? as usize;
 

zerotier-system-service/rootsets/root.zerotier.com.json

@@ -1,25 +0,0 @@
-{
-  "name": "root.zerotier.com",
-  "revision": 1,
-  "members": [ {
-      "identity": "62f865ae71:0:e2076c57de870e6288d7d5e7404408b1545efca37d67f77b87e9e54168c25d3ef1a9abf2905ea5e785c01dff23887ad4232d95c7a8fd2c27111a72bd159322dc",
-      "endpoints": [ "udp:50.7.252.138/9993", "udp:2001:49f0:d0db:2::2/9993" ],
-      "signature": [ 1, 45, 14, 211, 108, 240, 151, 85, 43, 241, 113, 18, 24, 45, 198, 197, 67, 254, 96, 138, 194, 77, 170, 156, 168, 31, 240, 55, 168, 108, 69, 135, 253, 198, 153, 36, 166, 200, 222, 157, 122, 50, 149, 149, 40, 35, 125, 93, 78, 228, 51, 245, 53, 238, 133, 84, 188, 190, 98, 145, 177, 19, 54, 154, 0 ],
-      "flags": 0
-    }, {
-      "identity": "778cde7190:0:3f6681a99e5ad1895e9fba33e6212d4454e168bcec7112101bf000956ed8e92e42892cb6f2ec410881a84ab19da50e1287ba3d926c3a1f755cccf299a1207055",
-      "endpoints": [ "udp:103.195.103.66/9993", "udp:2605:9880:400:c3:254:f2bc:a1f7:19/9993" ],
-      "signature": [ 1, 202, 181, 145, 69, 58, 169, 42, 149, 210, 160, 77, 220, 56, 246, 54, 210, 161, 144, 158, 103, 70, 104, 236, 58, 66, 127, 100, 117, 242, 208, 70, 68, 87, 142, 163, 222, 231, 146, 60, 205, 180, 202, 18, 181, 137, 216, 204, 109, 118, 224, 86, 220, 26, 142, 61, 18, 50, 174, 173, 44, 167, 231, 249, 0 ],
-      "flags": 0
-    }, {
-      "identity": "cafe04eba9:0:6c6a9d1dea55c1616bfe2a2b8f0ff9a8cacaf70374fb1f39e3bef81cbfebef17b7228268a0a2a29d3488c752565c6c965cbd6506ec24397cc8a5d9d15285a87f",
-      "endpoints": [ "udp:84.17.53.155/9993", "udp:2a02:6ea0:d405::9993/9993" ],
-      "signature": [ 1, 129, 31, 37, 249, 242, 179, 153, 184, 117, 15, 192, 41, 69, 112, 196, 189, 18, 57, 96, 33, 82, 31, 142, 57, 251, 151, 118, 86, 71, 11, 170, 197, 11, 20, 55, 74, 66, 10, 248, 133, 216, 88, 212, 34, 139, 128, 179, 246, 241, 8, 126, 105, 195, 126, 235, 140, 219, 66, 92, 166, 203, 111, 132, 0 ],
-      "flags": 0
-    }, {
-      "identity": "cafe9efeb9:0:ccdef76bc7b97ded904eabc5df09886d9c1514a610036cb9139cc214001a2958978efcec15712dd3948c6e6b3a8e893df01ff493d1f8d9806a860c5420571bf0",
-      "endpoints": [ "udp:104.194.8.134/9993", "udp:2605:9880:200:1200:30:571:e34:51/9993" ],
-      "signature": [ 1, 254, 236, 249, 244, 29, 229, 55, 85, 171, 15, 42, 222, 51, 237, 237, 47, 54, 158, 123, 96, 24, 101, 207, 63, 82, 113, 254, 154, 225, 188, 147, 75, 115, 243, 200, 253, 221, 198, 234, 74, 168, 126, 13, 137, 143, 13, 56, 73, 206, 242, 29, 97, 8, 221, 31, 236, 187, 86, 190, 15, 65, 184, 253, 13 ],
-      "flags": 0
-    } ]
-}

zerotier-system-service/src/cli/rootset.rs

@@ -30,7 +30,7 @@ pub async fn cmd(flags: Flags, cmd_args: &ArgMatches) -> i32 {
                 let path = path.unwrap();
                 let secret_arg = secret_arg.unwrap();
                 let secret = crate::utils::parse_cli_identity(secret_arg, true).await;
-                let json_data = crate::utils::read_limit(path, 1048576).await;
+                let json_data = crate::utils::read_limit(path, crate::utils::DEFAULT_FILE_IO_READ_LIMIT).await;
                 if secret.is_err() {
                     eprintln!("ERROR: unable to parse '{}' or read as a file.", secret_arg);
                     return exitcode::ERR_IOERR;
@@ -66,7 +66,7 @@ pub async fn cmd(flags: Flags, cmd_args: &ArgMatches) -> i32 {
             let path = sc_args.value_of("path");
             if path.is_some() {
                 let path = path.unwrap();
-                let json_data = crate::utils::read_limit(path, 1048576).await;
+                let json_data = crate::utils::read_limit(path, crate::utils::DEFAULT_FILE_IO_READ_LIMIT).await;
                 if json_data.is_err() {
                     eprintln!("ERROR: unable to read '{}'.", path);
                     return exitcode::ERR_IOERR;

zerotier-system-service/src/jsonformatter.rs

@@ -7,7 +7,6 @@
 
 use serde_json::ser::Formatter;
 
-#[derive(Clone, Debug)]
 pub struct JsonFormatter<'a> {
     current_indent: usize,
     has_value: bool,

zerotier-system-service/src/localconfig.rs

@@ -13,6 +13,7 @@ use serde::{Deserialize, Serialize};
 use zerotier_network_hypervisor::vl1::{Address, InetAddress};
 use zerotier_network_hypervisor::vl2::NetworkId;
 
+/// A list of unassigned or obsolete ports under 1024 that could possibly be squatted.
 pub const UNASSIGNED_PRIVILEGED_PORTS: [u16; 299] = [
     4, 6, 8, 10, 12, 14, 15, 16, 26, 28, 30, 32, 34, 36, 40, 60, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 285, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 323, 324, 325, 326, 327, 328,
     329, 330, 331, 332, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 703, 708, 713, 714, 715, 716, 717, 718, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728, 732, 733, 734, 735, 736, 737, 738, 739, 740, 743, 745, 746, 755, 756, 766, 768, 778, 779,
@@ -22,36 +23,37 @@ pub const UNASSIGNED_PRIVILEGED_PORTS: [u16; 299] = [
     954, 955, 956, 957, 958, 959, 960, 961, 962, 963, 964, 965, 966, 967, 968, 969, 970, 971, 972, 973, 974, 975, 976, 977, 978, 979, 980, 981, 982, 983, 984, 985, 986, 987, 988, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1023,
 ];
 
+/// Default primary ZeroTier port.
 pub const DEFAULT_PORT: u16 = 9993;
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(default)]
-pub struct LocalConfigPhysicalPathConfig {
+pub struct PhysicalPathSettings {
     pub blacklist: bool,
 }
 
-impl Default for LocalConfigPhysicalPathConfig {
+impl Default for PhysicalPathSettings {
     fn default() -> Self {
-        LocalConfigPhysicalPathConfig { blacklist: false }
+        Self { blacklist: false }
     }
 }
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(default)]
-pub struct LocalConfigVirtualConfig {
+pub struct VirtualNetworkSettings {
     #[serde(rename = "try")]
     pub try_: Vec<InetAddress>,
 }
 
-impl Default for LocalConfigVirtualConfig {
+impl Default for VirtualNetworkSettings {
     fn default() -> Self {
-        LocalConfigVirtualConfig { try_: Vec::new() }
+        Self { try_: Vec::new() }
     }
 }
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(default)]
-pub struct LocalConfigNetworkSettings {
+pub struct NetworkSettings {
     #[serde(rename = "allowManagedIPs")]
     pub allow_managed_ips: bool,
     #[serde(rename = "allowGlobalIPs")]
@@ -64,9 +66,9 @@ pub struct LocalConfigNetworkSettings {
     pub allow_default_route_override: bool,
 }
 
-impl Default for LocalConfigNetworkSettings {
+impl Default for NetworkSettings {
     fn default() -> Self {
-        LocalConfigNetworkSettings {
+        Self {
             allow_managed_ips: true,
             allow_global_ips: false,
             allow_managed_routes: true,
@@ -78,78 +80,43 @@ impl Default for LocalConfigNetworkSettings {
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(default)]
-pub struct LocalConfigLogSettings {
+pub struct GlobalSettings {
-    pub path: Option<String>,
-    #[serde(rename = "maxSize")]
-    pub max_size: usize,
-    pub vl1: bool,
-    pub vl2: bool,
-    #[serde(rename = "vl2TraceRules")]
-    pub vl2_trace_rules: bool,
-    #[serde(rename = "vl2TraceMulticast")]
-    pub vl2_trace_multicast: bool,
-    pub debug: bool,
-    pub stderr: bool,
-}
-
-impl Default for LocalConfigLogSettings {
-    fn default() -> Self {
-        // TODO: change before release to saner defaults
-        LocalConfigLogSettings {
-            path: None,
-            max_size: 131072,
-            vl1: true,
-            vl2: true,
-            vl2_trace_rules: true,
-            vl2_trace_multicast: true,
-            debug: true,
-            stderr: true,
-        }
-    }
-}
-
-#[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
-#[serde(default)]
-pub struct LocalConfigSettings {
     #[serde(rename = "primaryPort")]
     pub primary_port: u16,
     #[serde(rename = "portMapping")]
     pub port_mapping: bool,
-    #[serde(rename = "log")]
-    pub log: LocalConfigLogSettings,
     #[serde(rename = "interfacePrefixBlacklist")]
     pub interface_prefix_blacklist: Vec<String>,
     #[serde(rename = "explicitAddresses")]
     pub explicit_addresses: Vec<InetAddress>,
 }
 
-impl Default for LocalConfigSettings {
+impl Default for GlobalSettings {
     fn default() -> Self {
         let mut bl: Vec<String> = Vec::new();
-        bl.reserve(LocalConfigSettings::DEFAULT_PREFIX_BLACKLIST.len());
+        bl.reserve(Self::DEFAULT_PREFIX_BLACKLIST.len());
-        for n in LocalConfigSettings::DEFAULT_PREFIX_BLACKLIST.iter() {
+        for n in Self::DEFAULT_PREFIX_BLACKLIST.iter() {
             bl.push(String::from(*n));
         }
 
-        LocalConfigSettings {
+        Self {
             primary_port: DEFAULT_PORT,
             port_mapping: true,
-            log: LocalConfigLogSettings::default(),
             interface_prefix_blacklist: bl,
             explicit_addresses: Vec::new(),
         }
     }
 }
 
-impl LocalConfigSettings {
+impl GlobalSettings {
     #[cfg(target_os = "macos")]
-    const DEFAULT_PREFIX_BLACKLIST: [&'static str; 9] = ["lo", "utun", "gif", "stf", "iptap", "pktap", "feth", "zt", "llw"];
+    pub const DEFAULT_PREFIX_BLACKLIST: [&'static str; 9] = ["lo", "utun", "gif", "stf", "iptap", "pktap", "feth", "zt", "llw"];
 
     #[cfg(target_os = "linux")]
-    const DEFAULT_PREFIX_BLACKLIST: [&'static str; 5] = ["lo", "tun", "tap", "ipsec", "zt"];
+    pub const DEFAULT_PREFIX_BLACKLIST: [&'static str; 5] = ["lo", "tun", "tap", "ipsec", "zt", "tailscale"];
 
     #[cfg(windows)]
-    const DEFAULT_PREFIX_BLACKLIST: [&'static str; 0] = [];
+    pub const DEFAULT_PREFIX_BLACKLIST: [&'static str; 0] = [];
 
     pub fn is_interface_blacklisted(&self, ifname: &str) -> bool {
         for p in self.interface_prefix_blacklist.iter() {
@@ -163,21 +130,66 @@ impl LocalConfigSettings {
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq)]
 #[serde(default)]
-pub struct LocalConfig {
+pub struct Config {
-    pub physical: BTreeMap<InetAddress, LocalConfigPhysicalPathConfig>,
+    pub physical: BTreeMap<InetAddress, PhysicalPathSettings>,
     #[serde(rename = "virtual")]
-    pub virtual_: BTreeMap<Address, LocalConfigVirtualConfig>,
+    pub virtual_: BTreeMap<Address, VirtualNetworkSettings>,
-    pub network: BTreeMap<NetworkId, LocalConfigNetworkSettings>,
+    pub network: BTreeMap<NetworkId, NetworkSettings>,
-    pub settings: LocalConfigSettings,
+    pub settings: GlobalSettings,
+
+    #[serde(skip_serializing, skip_deserializing)]
+    file_content_hash: [u8; 48],
 }
 
-impl Default for LocalConfig {
+impl Default for Config {
     fn default() -> Self {
-        LocalConfig {
+        Self {
             physical: BTreeMap::new(),
             virtual_: BTreeMap::new(),
             network: BTreeMap::new(),
-            settings: LocalConfigSettings::default(),
+            settings: GlobalSettings::default(),
+            file_content_hash: [0_u8; 48],
+        }
+    }
+}
+
+impl Config {
+    /// Load this configuration from disk.
+    pub async fn load(path: &str) -> std::io::Result<Self> {
+        let mut t = Self::default();
+        t.reload(path).await.map(|_| t)
+    }
+
+    /// Load this configuration from disk if its contents have changed.
+    ///
+    /// This returns true if a new configuration was loaded, false if the file hasn't changed, or an error.
+    pub async fn reload(&mut self, path: &str) -> std::io::Result<bool> {
+        let config_data = crate::utils::read_limit(path, crate::utils::DEFAULT_FILE_IO_READ_LIMIT).await?;
+        let hash = zerotier_core_crypto::hash::SHA384::hash(config_data.as_slice());
+        Ok(if hash != self.file_content_hash {
+            let config = serde_json::from_slice(config_data.as_slice());
+            if config.is_err() {
+                return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, config.err().unwrap().to_string()));
+            }
+            *self = config.unwrap();
+            self.file_content_hash = hash;
+            true
+        } else {
+            false
+        })
+    }
+
+    /// Write this configuration to a file (with human-friendly formatting).
+    ///
+    /// This is mutable because it updates an external state if the write is successful.
+    pub async fn save(&mut self, path: &str) -> std::io::Result<()> {
+        let config_data = crate::utils::to_json_pretty(self);
+        let result = tokio::fs::write(path, &config_data).await;
+        if result.is_ok() {
+            self.file_content_hash = zerotier_core_crypto::hash::SHA384::hash(config_data.as_bytes());
+            Ok(())
+        } else {
+            result
         }
     }
 }

zerotier-system-service/src/main.rs

@@ -86,7 +86,6 @@ Advanced Operations:
 ·   list                                   List root sets in use
     sign <path> <?identity secret>         Sign a root set with an identity
     verify <path>                          Load and verify a root set
-    marshal <path>                         Dump root set as binary to stdout
 
   service                                  Start local service
    (usually not invoked manually)
@@ -105,12 +104,12 @@ pub fn print_help() {
     let _ = std::io::stdout().write_all(h.as_bytes());
 }
 
-#[cfg(any(target_os = "macos"))]
+#[cfg(target_os = "macos")]
 pub fn platform_default_home_path() -> String {
     "/Library/Application Support/ZeroTier".into()
 }
 
-#[cfg(any(target_os = "linux"))]
+#[cfg(target_os = "linux")]
 pub fn platform_default_home_path() -> String {
     "/var/lib/zerotier".into()
 }

zerotier-system-service/src/utils.rs

@@ -6,22 +6,24 @@
  * https://www.zerotier.com/
  */
 
-use std::error::Error;
 use std::str::FromStr;
 use std::time::{Instant, SystemTime, UNIX_EPOCH};
 
 use serde::de::DeserializeOwned;
-use serde::{Serialize, Serializer};
+use serde::Serialize;
 
 use lazy_static::lazy_static;
 
 use tokio::fs::File;
-use tokio::io::{AsyncRead, AsyncReadExt};
+use tokio::io::AsyncReadExt;
 
 use crate::jsonformatter::JsonFormatter;
 
 use zerotier_network_hypervisor::vl1::Identity;
 
+/// Default sanity limit parameter for read_limit() used throughout the service.
+pub const DEFAULT_FILE_IO_READ_LIMIT: usize = 1048576;
+
 lazy_static! {
     static ref STARTUP_INSTANT: Instant = Instant::now();
 }