Add IPv6 support to DD_AGENT_HOST

ext/coms.c

@@ -658,7 +658,8 @@ static ddtrace_coms_stack_t *_dd_coms_attempt_acquire_stack(void) {
 }
 
 #define TRACE_PATH_STR "/v0.4/traces"
-#define HOST_FORMAT_STR "http://%s:%u"
+#define HOST_V6_FORMAT_STR "http://[%s]:%u"
+#define HOST_V4_FORMAT_STR "http://%s:%u"
 #define DEFAULT_UDS_PATH "/var/run/datadog/apm.socket"
 
 static struct curl_slist *dd_agent_curl_headers = NULL;
@@ -729,12 +730,14 @@ char *ddtrace_agent_url(void) {
     }
 
     if (ZSTR_LEN(hostname) > 0) {
+        bool isIPv6 = memchr(ZSTR_VAL(hostname), ':', ZSTR_LEN(hostname));
+
         int64_t port = get_global_DD_TRACE_AGENT_PORT();
         if (port <= 0 || port > 65535) {
             port = 8126;
         }
         char *formatted_url;
-        asprintf(&formatted_url, HOST_FORMAT_STR, ZSTR_VAL(hostname), (uint32_t)port);
+        asprintf(&formatted_url, isIPv6 ? HOST_V6_FORMAT_STR : HOST_V4_FORMAT_STR, ZSTR_VAL(hostname), (uint32_t)port);
         return formatted_url;
     }
 
@@ -747,7 +750,7 @@ char *ddtrace_agent_url(void) {
         port = 8126;
     }
     char *formatted_url;
-    asprintf(&formatted_url, HOST_FORMAT_STR, "localhost", (uint32_t)port);
+    asprintf(&formatted_url, HOST_V4_FORMAT_STR, "localhost", (uint32_t)port);
     return formatted_url;
 }
 

profiling/src/lib.rs

@@ -689,8 +689,13 @@ fn detect_uri_from_config(
     if port.is_some() || host.is_some() {
         let host = host.unwrap_or(Cow::Borrowed("localhost"));
         let port = port.unwrap_or(8126u16);
+        let url = if host.contains(':') {
+            format!("http://[{host}]:{port}")
+        } else {
+            format!("http://{host}:{port}")
+        };
 
-        match Uri::from_str(format!("http://{host}:{port}").as_str()) {
+        match Uri::from_str(url.as_str()) {
             Ok(uri) => return AgentEndpoint::Uri(uri),
             Err(err) => {
                 warn!("The combination of DD_AGENT_HOST({host}) and DD_TRACE_AGENT_PORT({port}) was not a valid URL: {err}")
@@ -1181,3 +1186,65 @@ fn is_zend_mm() -> bool {
         unsafe { zend::is_zend_mm() }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn detect_uri_from_config_works() {
+        // expected
+        let endpoint = detect_uri_from_config(
+            None,
+            None,
+            None
+        );
+        let expected = AgentEndpoint::default();
+        assert_eq!(endpoint, expected);
+
+        // ipv4 host
+        let endpoint = detect_uri_from_config(
+            None,
+            Some(Cow::Owned("127.0.0.1".to_owned())),
+            None
+        );
+        let expected = AgentEndpoint::Uri(Uri::from_static("http://127.0.0.1:8126"));
+        assert_eq!(endpoint, expected);
+
+        // ipv6 host
+        let endpoint = detect_uri_from_config(
+            None,
+            Some(Cow::Owned("::1".to_owned())),
+            None
+        );
+        let expected = AgentEndpoint::Uri(Uri::from_static("http://[::1]:8126"));
+        assert_eq!(endpoint, expected);
+
+        // ipv6 host, custom port
+        let endpoint = detect_uri_from_config(
+            None,
+            Some(Cow::Owned("::1".to_owned())),
+            Some(9000),
+        );
+        let expected = AgentEndpoint::Uri(Uri::from_static("http://[::1]:9000"));
+        assert_eq!(endpoint, expected);
+
+        // agent_url
+        let endpoint = detect_uri_from_config(
+            Some(Cow::Owned("http://[::1]:8126".to_owned())),
+            None,
+            None,
+        );
+        let expected = AgentEndpoint::Uri(Uri::from_static("http://[::1]:8126"));
+        assert_eq!(endpoint, expected);
+
+        // fallback on non existing UDS
+        let endpoint = detect_uri_from_config(
+            Some(Cow::Owned("unix://foo/bar/baz/I/do/not/exist".to_owned())),
+            None,
+            None,
+        );
+        let expected = AgentEndpoint::default();
+        assert_eq!(endpoint, expected);
+    }
+}

tests/ext/background-sender/background_sender_ipv6_support.phpt

@@ -0,0 +1,18 @@
+--TEST--
+DD_AGENT_HOST with IPv6 works
+--SKIPIF--
+<?php include __DIR__ . '/../startup_logging_skipif.inc'; ?>
+--ENV--
+DD_AGENT_HOST=::1
+--FILE--
+<?php
+include_once __DIR__ . '/../startup_logging.inc';
+
+$logs = dd_get_startup_logs([], ['DD_TRACE_DEBUG=1']);
+
+dd_dump_startup_logs($logs, [
+    'agent_url',
+]);
+?>
+--EXPECT--
+agent_url: "http://[::1]:8126"