From a9fc9bb627b4bbe61943fa2e9cdcd6631ab7ae2f Mon Sep 17 00:00:00 2001
From: Zihan Dai <dzh1436286758@gmail.com>
Date: Wed, 11 Nov 2026 13:41:21 +1100
Subject: [PATCH] Fix DomainNamingService rejecting IPv6 addresses

The http://, https:// and redis:// naming services cut the host at the
first colon, so an address such as `[::1]:8765` failed with "No port
after colon" and a channel initialized with a load balancer could not
select any server. Keep the bracketed address as the host and turn it
into an endpoint directly, since there is nothing to resolve.
---
 src/brpc/policy/domain_naming_service.cpp | 42 ++++++++++++++++++-----
 test/brpc_naming_service_unittest.cpp     | 28 +++++++++++++++
 2 files changed, 62 insertions(+), 8 deletions(-)

diff --git a/src/brpc/policy/domain_naming_service.cpp b/src/brpc/policy/domain_naming_service.cpp
index 8c2632cd6e..d1705575b5 100644
--- a/src/brpc/policy/domain_naming_service.cpp
+++ b/src/brpc/policy/domain_naming_service.cpp
@@ -19,6 +19,7 @@
 #include "butil/build_config.h"                       // OS_MACOSX
 #include <netdb.h>                                    // gethostbyname_r
 #include <stdlib.h>                                   // strtol
+#include <string.h>                                   // strchr, memcpy
 #include <string>                                     // std::string
 #include "bthread/bthread.h"
 #include "brpc/log.h"
@@ -44,15 +45,29 @@ int DomainNamingService::GetServers(const char* dns_name,
     // Should be enough to hold host name
     char buf[256];
     size_t i = 0;
-    for (; i < sizeof(buf) - 1 && dns_name[i] != '\0'
-             && dns_name[i] != ':' && dns_name[i] != '/'; ++i) {
-        buf[i] = dns_name[i];
-    }
-    if (i == sizeof(buf) - 1) {
-        LOG(ERROR) << "dns_name=`" << dns_name << "' is too long";
-        return -1;
+    if (dns_name[0] == '[') {
+        // IPv6 address such as `[::1]:8080'. Keep the brackets, which
+        // butil::str2endpoint() expects.
+        const char* close = strchr(dns_name, ']');
+        if (close == nullptr ||
+            static_cast<size_t>(close - dns_name) + 1 >= sizeof(buf) ||
+            (close[1] != '\0' && close[1] != ':' && close[1] != '/')) {
+            LOG(ERROR) << "Invalid ipv6 address in `" << dns_name << '\'';
+            return -1;
+        }
+        i = close - dns_name + 1;
+        memcpy(buf, dns_name, i);
+    } else {
+        for (; i < sizeof(buf) - 1 && dns_name[i] != '\0'
+                 && dns_name[i] != ':' && dns_name[i] != '/'; ++i) {
+            buf[i] = dns_name[i];
+        }
+        if (i == sizeof(buf) - 1) {
+            LOG(ERROR) << "dns_name=`" << dns_name << "' is too long";
+            return -1;
+        }
     }
-    
+
     buf[i] = '\0';
     int port = _default_port;
     if (dns_name[i] == ':') {
@@ -79,6 +94,17 @@ int DomainNamingService::GetServers(const char* dns_name,
         return -1;
     }
 
+    if (buf[0] == '[') {
+        // An address, not a name: nothing to resolve.
+        butil::EndPoint point;
+        if (butil::str2endpoint(buf, port, &point) != 0) {
+            LOG(ERROR) << "Invalid ipv6 address in `" << dns_name << '\'';
+            return -1;
+        }
+        servers->push_back(ServerNode(point, std::string()));
+        return 0;
+    }
+
     if (FLAGS_dns_support_ipv6) {
         struct addrinfo hints;
         struct addrinfo* addrResult;
diff --git a/test/brpc_naming_service_unittest.cpp b/test/brpc_naming_service_unittest.cpp
index a01e033f61..97d771017d 100644
--- a/test/brpc_naming_service_unittest.cpp
+++ b/test/brpc_naming_service_unittest.cpp
@@ -164,6 +164,34 @@ TEST(NamingServiceTest, sanity) {
     }
 }
 
+TEST(NamingServiceTest, domain_with_ipv6_address) {
+    std::vector<brpc::ServerNode> servers;
+    brpc::policy::DomainNamingService dns;
+
+    ASSERT_EQ(0, dns.GetServers("[::1]:1234", &servers));
+    ASSERT_EQ(1u, servers.size());
+    ASSERT_STREQ("[::1]:1234", butil::endpoint2str(servers[0].addr).c_str());
+
+    ASSERT_EQ(0, dns.GetServers("[fdbd:dc03:ff:501:b783:830f:f0f5:aa6a]:2280", &servers));
+    ASSERT_EQ(1u, servers.size());
+    ASSERT_STREQ("[fdbd:dc03:ff:501:b783:830f:f0f5:aa6a]:2280",
+                 butil::endpoint2str(servers[0].addr).c_str());
+
+    ASSERT_EQ(0, dns.GetServers("[::1]:1234/useless1/useless2", &servers));
+    ASSERT_EQ(1u, servers.size());
+    ASSERT_STREQ("[::1]:1234", butil::endpoint2str(servers[0].addr).c_str());
+
+    ASSERT_EQ(0, dns.GetServers("[::1]", &servers));
+    ASSERT_EQ(1u, servers.size());
+    ASSERT_STREQ("[::1]:80", butil::endpoint2str(servers[0].addr).c_str());
+
+    ASSERT_EQ(-1, dns.GetServers("[::1", &servers));
+    ASSERT_EQ(-1, dns.GetServers("[::1]:", &servers));
+    ASSERT_EQ(-1, dns.GetServers("[::1]1234", &servers));
+    ASSERT_EQ(-1, dns.GetServers("[::1]:99999", &servers));
+    ASSERT_EQ(-1, dns.GetServers("[not-an-ip]:1234", &servers));
+}
+
 TEST(NamingServiceTest, invalid_port) {
     std::vector<brpc::ServerNode> servers;