Fix AF_INET6 accept(0 address handling

mrexodia · mrexodia · commit 6ff4869fd9c8 · 2026-02-20T16:18:38.000+01:00
diff --git a/ixwebsocket/IXSocketServer.cpp b/ixwebsocket/IXSocketServer.cpp
@@ -308,13 +308,12 @@ namespace ix
             }
 
             // Accept a connection.
-            // FIXME: Is this working for ipv6 ?
-            struct sockaddr_in client; // client address information
-            int clientFd;              // socket connected to client
-            socklen_t addressLen = sizeof(client);
-            memset(&client, 0, sizeof(client));
+            sockaddr_storage clientStorage; // client address information (v4 or v6)
+            int clientFd;                   // socket connected to client
+            socklen_t addressLen = sizeof(clientStorage);
+            memset(&clientStorage, 0, sizeof(clientStorage));
 
-            if ((clientFd = accept(_serverFd, (struct sockaddr*) &client, &addressLen)) < 0)
+            if ((clientFd = accept(_serverFd, (struct sockaddr*) &clientStorage, &addressLen)) < 0)
             {
                 if (!Socket::isWaitNeeded())
                 {
@@ -346,8 +345,10 @@ namespace ix
 
             if (_addressFamily == AF_INET)
             {
+                auto* client = reinterpret_cast<sockaddr_in*>(&clientStorage);
+
                 char remoteIp4[INET_ADDRSTRLEN];
-                if (ix::inet_ntop(AF_INET, &client.sin_addr, remoteIp4, INET_ADDRSTRLEN) == nullptr)
+                if (ix::inet_ntop(AF_INET, &client->sin_addr, remoteIp4, INET_ADDRSTRLEN) == nullptr)
                 {
                     int err = Socket::getErrno();
                     std::stringstream ss;
@@ -360,13 +361,15 @@ namespace ix
                     continue;
                 }
 
-                remotePort = ix::network_to_host_short(client.sin_port);
+                remotePort = ix::network_to_host_short(client->sin_port);
                 remoteIp = remoteIp4;
             }
             else // AF_INET6
             {
+                auto* client = reinterpret_cast<sockaddr_in6*>(&clientStorage);
+
                 char remoteIp6[INET6_ADDRSTRLEN];
-                if (ix::inet_ntop(AF_INET6, &client.sin_addr, remoteIp6, INET6_ADDRSTRLEN) ==
+                if (ix::inet_ntop(AF_INET6, &client->sin6_addr, remoteIp6, INET6_ADDRSTRLEN) ==
                     nullptr)
                 {
                     int err = Socket::getErrno();
@@ -380,7 +383,7 @@ namespace ix
                     continue;
                 }
 
-                remotePort = ix::network_to_host_short(client.sin_port);
+                remotePort = ix::network_to_host_short(client->sin6_port);
                 remoteIp = remoteIp6;
             }
 

Original file line number	Diff line number	Diff line change
`@@ -308,13 +308,12 @@ namespace ix`
`308`	`308`	`}`
`309`	`309`
`310`	`310`	`// Accept a connection.`
`311`		`- // FIXME: Is this working for ipv6 ?`
`312`		`- struct sockaddr_in client; // client address information`
`313`		`- int clientFd; // socket connected to client`
`314`		`- socklen_t addressLen = sizeof(client);`
`315`		`- memset(&client, 0, sizeof(client));`
	`311`	`+ sockaddr_storage clientStorage; // client address information (v4 or v6)`
	`312`	`+ int clientFd; // socket connected to client`
	`313`	`+ socklen_t addressLen = sizeof(clientStorage);`
	`314`	`+ memset(&clientStorage, 0, sizeof(clientStorage));`
`316`	`315`
`317`		`- if ((clientFd = accept(_serverFd, (struct sockaddr*) &client, &addressLen)) < 0)`
	`316`	`+ if ((clientFd = accept(_serverFd, (struct sockaddr*) &clientStorage, &addressLen)) < 0)`
`318`	`317`	`{`
`319`	`318`	`if (!Socket::isWaitNeeded())`
`320`	`319`	`{`
`@@ -346,8 +345,10 @@ namespace ix`
`346`	`345`
`347`	`346`	`if (_addressFamily == AF_INET)`
`348`	`347`	`{`
	`348`	`+ auto* client = reinterpret_cast<sockaddr_in*>(&clientStorage);`
	`349`	`+`
`349`	`350`	`char remoteIp4[INET_ADDRSTRLEN];`
`350`		`- if (ix::inet_ntop(AF_INET, &client.sin_addr, remoteIp4, INET_ADDRSTRLEN) == nullptr)`
	`351`	`+ if (ix::inet_ntop(AF_INET, &client->sin_addr, remoteIp4, INET_ADDRSTRLEN) == nullptr)`
`351`	`352`	`{`
`352`	`353`	`int err = Socket::getErrno();`
`353`	`354`	`std::stringstream ss;`
`@@ -360,13 +361,15 @@ namespace ix`
`360`	`361`	`continue;`
`361`	`362`	`}`
`362`	`363`
`363`		`- remotePort = ix::network_to_host_short(client.sin_port);`
	`364`	`+ remotePort = ix::network_to_host_short(client->sin_port);`
`364`	`365`	`remoteIp = remoteIp4;`
`365`	`366`	`}`
`366`	`367`	`else // AF_INET6`
`367`	`368`	`{`
	`369`	`+ auto* client = reinterpret_cast<sockaddr_in6*>(&clientStorage);`
	`370`	`+`
`368`	`371`	`char remoteIp6[INET6_ADDRSTRLEN];`
`369`		`- if (ix::inet_ntop(AF_INET6, &client.sin_addr, remoteIp6, INET6_ADDRSTRLEN) ==`
	`372`	`+ if (ix::inet_ntop(AF_INET6, &client->sin6_addr, remoteIp6, INET6_ADDRSTRLEN) ==`
`370`	`373`	`nullptr)`
`371`	`374`	`{`
`372`	`375`	`int err = Socket::getErrno();`
`@@ -380,7 +383,7 @@ namespace ix`
`380`	`383`	`continue;`
`381`	`384`	`}`
`382`	`385`
`383`		`- remotePort = ix::network_to_host_short(client.sin_port);`
	`386`	`+ remotePort = ix::network_to_host_short(client->sin6_port);`
`384`	`387`	`remoteIp = remoteIp6;`
`385`	`388`	`}`
`386`	`389`