feat: add internal host detection support (#384)

Cargo.lock

@@ -889,6 +889,18 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bd0c93bb4b0c6d9b77f4435b0ae98c24d17f1c45b2ff844c6151a07256ca923b"
 
+[[package]]
+name = "dns-lookup"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5766087c2235fec47fafa4cfecc81e494ee679d0fd4a59887ea0919bfb0e4fc"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "socket2",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "document-features"
 version = "0.2.8"
@@ -1424,6 +1436,7 @@ dependencies = [
  "base64 0.21.5",
  "chacha20poly1305",
  "clap",
+ "dns-lookup",
  "log",
  "md5",
  "open",

Cargo.toml

@@ -17,6 +17,7 @@ base64 = "0.21"
 clap = { version = "4.4.2", features = ["derive"] }
 ctrlc = "3.4"
 directories = "5.0"
+dns-lookup = "2.0.4"
 env_logger = "0.10"
 is_executable = "1.0"
 log = "0.4"

crates/gpapi/Cargo.toml

@@ -7,6 +7,7 @@ license = "MIT"
 [dependencies]
 anyhow.workspace = true
 base64.workspace = true
+dns-lookup.workspace = true
 log.workspace = true
 reqwest.workspace = true
 openssl.workspace = true

crates/gpapi/src/gateway/parse_gateways.rs

@@ -2,9 +2,17 @@ use roxmltree::Document;
 
 use super::{Gateway, PriorityRule};
 
-pub(crate) fn parse_gateways(doc: &Document) -> Option<Vec<Gateway>> {
+pub(crate) fn parse_gateways(doc: &Document, external: bool) -> Option<Vec<Gateway>> {
   let node_gateways = doc.descendants().find(|n| n.has_tag_name("gateways"))?;
-  let list_gateway = node_gateways.descendants().find(|n| n.has_tag_name("list"))?;
+
+  // if external flag is set, look for external gateways, otherwise look for internal gateways
+  let kind_gateways = if external {
+    node_gateways.descendants().find(|n| n.has_tag_name("external"))?
+  } else {
+    node_gateways.descendants().find(|n| n.has_tag_name("internal"))?
+  };
+
+  let list_gateway = kind_gateways.descendants().find(|n| n.has_tag_name("list"))?;
 
   let gateways = list_gateway
     .children()

crates/gpapi/src/portal/config.rs

@@ -1,4 +1,5 @@
 use anyhow::bail;
+use dns_lookup::lookup_addr;
 use log::{info, warn};
 use reqwest::{Client, StatusCode};
 use roxmltree::Document;
@@ -125,7 +126,38 @@ pub async fn retrieve_config(portal: &str, cred: &Credential, gp_params: &GpPara
 
   let doc = Document::parse(&res_xml).map_err(|e| PortalError::ConfigError(e.to_string()))?;
 
-  let mut gateways = parse_gateways(&doc).unwrap_or_else(|| {
+  let mut external_gateway = true;
+
+  // Perform DNS lookup, set flag to internal or external, and pass it to parse_gateways
+  if let Some(_) = xml::get_child_text(&doc, "internal-host-detection") {
+    let ip_info = [
+      (xml::get_child_text(&doc, "ip-address"), xml::get_child_text(&doc, "host")),
+      (xml::get_child_text(&doc, "ipv6-address"), xml::get_child_text(&doc, "ipv6-host")),
+    ];
+
+    info!("internal-host-detection returned, performing DNS lookup");
+
+    for (ip_address, host) in ip_info.iter() {
+      if let (Some(ip_address), Some(host)) = (ip_address.as_deref(), host.as_deref()) {
+        if !ip_address.is_empty() && !host.is_empty() {
+          match ip_address.parse::<std::net::IpAddr>() {
+            Ok(ip) => match lookup_addr(&ip) {
+              Ok(host_lookup) if host_lookup == *host => {
+                external_gateway = false;
+                break;
+              }
+              Ok(_) => (),
+              Err(err) => warn!("DNS lookup failed for {}: {}", ip_address, err),
+            },
+            Err(err) => warn!("Invalid IP address {}: {}", ip_address, err),
+          }
+        }
+      }
+    }
+  }
+
+
+  let mut gateways = parse_gateways(&doc, external_gateway).unwrap_or_else(|| {
     info!("No gateways found in portal config");
     vec![]
   });

crates/gpapi/tests/files/portal_config.xml

@@ -46,7 +46,26 @@
     <use-sso>yes</use-sso>
     <ip-address></ip-address>
     <host></host>
+    <internal-host-detection>
+      <ip-address></ip-address>
+      <host></host>
+      <ipv6-address/>
+      <ipv6-host/>
+    </internal-host-detection>
     <gateways>
+        <internal>
+          <list>
+                <entry name="xxx.xxx.xxx.xxx">
+                    <priority-rule>
+                        <entry name="Any">
+                            <priority>1</priority>
+                        </entry>
+                    </priority-rule>
+                    <priority>1</priority>
+                    <description>vpn_gateway</description>
+                </entry>
+            </list>
+        </internal>
         <cutoff-time>5</cutoff-time>
         <external>
             <list>
@@ -63,6 +82,19 @@
         </external>
     </gateways>
     <gateways-v6>
+        <internal>
+            <list>
+                <entry name="vpn_gateway">
+                    <ipv4>xxx.xxx.xxx.xxx</ipv4>
+                    <priority-rule>
+                        <entry name="Any">
+                            <priority>1</priority>
+                        </entry>
+                    </priority-rule>
+                    <priority>1</priority>
+                </entry>
+            </list>
+        </internal>
         <cutoff-time>5</cutoff-time>
         <external>
             <list>