Workaround for getpeername() issue

getpeername() is returning invalid addresses on ipv6 sockets accepted
with AcceptEx, filling only 16 bytes of the address structure.
Providing a workaround by saving the remote address returned by
GetAcceptExSockaddrs, which is valid.

src/Win32_Interop/win32_wsiocp.c

@@ -29,11 +29,13 @@
 #include "win32_wsiocp.h"
 #include "Win32_FDAPI.h"
 #include <errno.h>
+#include <assert.h>
 
 
 static void *iocpState;
 static HANDLE iocph;
 static fnGetSockState * aeGetSockState;
+static fnGetSockState * aeGetExistingSockState;
 static fnDelSockState * aeDelSockState;
 
 #define SUCCEEDED_WITH_IOCP(result)                        \
@@ -130,6 +132,7 @@ int aeWinAccept(int fd, struct sockaddr *sa, socklen_t *len) {
     SOCKADDR *premotesa;
     int locallen, remotelen;
     aacceptreq * areq;
+    aeSockState *acceptsockstate;
 
     if ((sockstate = aeGetSockState(iocpState, fd)) == NULL) {
         errno = WSAEINVAL;
@@ -169,6 +172,13 @@ int aeWinAccept(int fd, struct sockaddr *sa, socklen_t *len) {
 
     aeWinSocketAttach(acceptsock);
 
+    // Save remote address to support aeWinGetPeerName()
+    if ((acceptsockstate = aeGetExistingSockState(iocpState, acceptsock)) == NULL) {
+        errno = WSAEINVAL;
+        return SOCKET_ERROR;
+    }
+    memcpy(&acceptsockstate->remoteAddress, premotesa, remotelen);
+
     zfree(areq->buf);
     zfree(areq);
 
@@ -180,6 +190,20 @@ int aeWinAccept(int fd, struct sockaddr *sa, socklen_t *len) {
     return acceptsock;
 }
 
+int aeWinGetPeerName(int fd, struct sockaddr *addr, socklen_t * addrlen) {
+    aeSockState *sockState = aeGetExistingSockState(iocpState, fd);
+    if (sockState == NULL) {
+        errno = EBADF;
+        return -1;
+    } else {
+        if (sockState->remoteAddress.ss_family) {
+            memcpy(addr, &sockState->remoteAddress, *addrlen);
+            return 0;
+        } else {
+            return getpeername(fd, addr, addrlen);
+        }
+    }
+}
 
 /* after doing read caller needs to call done
  * so that we can continue to check for read events.
@@ -490,11 +514,15 @@ int aeWinCloseSocket(int fd) {
     return 0;
 }
 
-void aeWinInit(void *state, HANDLE iocp, fnGetSockState *getSockState,
-                                        fnDelSockState *delSockState) {
+void aeWinInit(void *state,
+                HANDLE iocp,
+                fnGetSockState *getSockState,
+                fnGetSockState *getExistingSockState,
+                fnDelSockState *delSockState) {
     iocpState = state;
     iocph = iocp;
     aeGetSockState = getSockState;
+    aeGetExistingSockState = getExistingSockState;
     aeDelSockState = delSockState;
 }
 

src/Win32_Interop/win32_wsiocp.h

@@ -56,6 +56,7 @@ typedef struct aeSockState {
     int wreqs;
     OVERLAPPED ov_read;
     list wreqlist;
+    SOCKADDR_STORAGE remoteAddress;
 } aeSockState;
 
 typedef aeSockState * fnGetSockState(void *apistate, int fd);
@@ -68,7 +69,7 @@ typedef void fnDelSockState(void *apistate, aeSockState *sockState);
 #define CONNECT_PENDING     0x002000
 #define CLOSE_PENDING       0x004000
 
-void aeWinInit(void *state, HANDLE iocp, fnGetSockState *getSockState, fnDelSockState *delSockState);
+void aeWinInit(void *state, HANDLE iocp, fnGetSockState *getSockState, fnGetSockState *getExistingSockState, fnDelSockState *delSockState);
 void aeWinCleanup();
 
 #endif

src/Win32_Interop/win32fixes.h

@@ -301,6 +301,7 @@ int aeWinSocketSend(int fd, char *buf, int len,
                     void *eventLoop, void *client, void *data, void *proc);
 int aeWinListen(int rfd, int backlog);
 int aeWinAccept(int fd, struct sockaddr *sa, socklen_t *len);
+int aeWinGetPeerName(int fd, struct sockaddr *addr, socklen_t * addrlen);
 int aeWinSocketConnect(int fd, const SOCKADDR_STORAGE *ss);
 int aeWinSocketConnectBind(int fd, const SOCKADDR_STORAGE *ss, const char* source_addr);
 

src/ae_wsiocp.c

@@ -90,6 +90,7 @@ aeSockState *aeGetSockState(void *apistate, int fd) {
         sockState->wreqs = 0;
         sockState->reqs = NULL;
         memset(&sockState->wreqlist, 0, sizeof(sockState->wreqlist));
+        memset(&sockState->remoteAddress, 0, sizeof(sockState->remoteAddress));
 
         if (listAddNodeHead(socklist, sockState) != NULL) {
             return sockState;
@@ -202,7 +203,7 @@ static int aeApiCreate(aeEventLoop *eventLoop) {
     state->setsize = eventLoop->setsize;
     eventLoop->apidata = state;
     /* initialize the IOCP socket code with state reference */
-    aeWinInit(state, state->iocp, aeGetSockState, aeDelSockState);
+    aeWinInit(state, state->iocp, aeGetSockState, aeGetExistingSockState, aeDelSockState);
     return 0;
 }
 

src/anet.c

@@ -646,7 +646,11 @@ int anetPeerToString(int fd, char *ip, size_t ip_len, int *port) {
     struct sockaddr_storage sa;
     socklen_t salen = sizeof(sa);
 
+#ifdef WIN32_IOCP
+    if (aeWinGetPeerName(fd,(struct sockaddr*)&sa,&salen) == -1) {
+#else
     if (getpeername(fd,(struct sockaddr*)&sa,&salen) == -1) {
+#endif
         if (port) *port = 0;
         ip[0] = '?';
         ip[1] = '\0';