diff --git a/mgetsockname.c b/mgetsockname.c
new file mode 100644
index 0000000..2982334
--- /dev/null
+++ b/mgetsockname.c
@@ -0,0 +1,57 @@
+#include "marignotti.h"
+#include <gno/kerntool.h>
+#include <errno.h>
+#include <string.h>
+
+#include <sys/socket.h>
+
+#pragma noroot
+#pragma optimize 79
+
+int mgetsockname(Entry *e, void *p1, void *p2, void *p3, void *p4, void *p5)
+{
+    LongWord addr;
+    Word port;
+    int len;
+    
+    xsockaddr_in *sock_addr = (xsockaddr_in *)p3;
+    int *addrlen = (int *)p4;
+    
+    if (!addrlen) return EINVAL;
+    if (!sock_addr) return EINVAL;
+
+    len = *addrlen;
+
+    // bsd { has char sin_len; char sin_family; ... }
+    // gno has { short sin_family; ... }
+
+    
+    IncBusy();
+    port = TCPIPGetSourcePort(e->ipid);
+    addr = TCPIPGetMyIPAddress();
+    DecBusy();
+    
+    memset(sock_addr, 0, len);
+    
+    // truncate missing data.
+    if (len >= 2)
+        sock_addr->sin_family = AF_INET;
+    
+    if (len >= 4)
+    {
+        asm {
+            lda <port;
+            xba
+            sta <port;
+        }
+        sock_addr->sin_port = port;
+    }
+    
+    if (len >= 8)
+    {
+        sock_addr->sin_addr = addr;
+    }
+    
+    
+    return 0;
+}
\ No newline at end of file