Rewrote to use the thread-safe version of gethostbyname() by forward-porting

the code used in 8.4, and added rudimentary support for getaddrinfo() (not
enabled by default, as no autoconf-ery written). Part of fix for [Bug 1618235]

2 files changed, 91 insertions, 12 deletions

diff --git a/ChangeLog b/ChangeLog
index 4431805..0786d4a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2007-11-13  Donal K. Fellows  <donal.k.fellows@man.ac.uk>
+
+	* unix/tclUnixChan.c (CreateSocketAddress): Rewrote to use the
+	thread-safe version of gethostbyname() by forward-porting the code
+	used in 8.4, and added rudimentary support for getaddrinfo() (not
+	enabled by default, as no autoconf-ery written). Part of fix for [Bug
+	1618235]
+
 2007-11-12  Jeff Hobbs  <jeffh@ActiveState.com>
 
 	* generic/tclGet.c (Tcl_Get, Tcl_GetInt): revert use of TclGet*
diff --git a/unix/tclUnixChan.c b/unix/tclUnixChan.c
index aeb8539..dc104f0 100644
--- a/unix/tclUnixChan.c
+++ b/unix/tclUnixChan.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclUnixChan.c,v 1.83 2007/11/05 19:37:07 andreas_kupries Exp $
+ * RCS: @(#) $Id: tclUnixChan.c,v 1.84 2007/11/13 14:06:05 dkf Exp $
  */
 
 #include "tclInt.h"	/* Internal definitions for Tcl. */
@@ -237,7 +237,8 @@ static TcpState *	CreateSocket(Tcl_Interp *interp, int port,
 			    const char *host, int server, const char *myaddr,
 			    int myport, int async);
 static int		CreateSocketAddress(struct sockaddr_in *sockaddrPtr,
-			    const char *host, int port);
+			    const char *host, int port, int willBind,
+			    const char **errorMsgPtr);
 static int		FileBlockModeProc(ClientData instanceData, int mode);
 static int		FileCloseProc(ClientData instanceData,
 			    Tcl_Interp *interp);
@@ -2469,14 +2470,15 @@ CreateSocket(
     struct sockaddr_in sockaddr;	/* socket address */
     struct sockaddr_in mysockaddr;	/* Socket address for client */
     TcpState *statePtr;
+    const char *errorMsg = NULL;
 
     sock = -1;
     origState = 0;
-    if (!CreateSocketAddress(&sockaddr, host, port)) {
+    if (!CreateSocketAddress(&sockaddr, host, port, 0, &errorMsg)) {
 	goto addressError;
     }
     if ((myaddr != NULL || myport != 0) &&
-	    !CreateSocketAddress(&mysockaddr, myaddr, myport)) {
+	    !CreateSocketAddress(&mysockaddr, myaddr, myport, 1, &errorMsg)) {
 	goto addressError;
     }
 
@@ -2608,6 +2610,9 @@ CreateSocket(
     if (interp != NULL) {
 	Tcl_AppendResult(interp, "couldn't open socket: ",
 		Tcl_PosixError(interp), NULL);
+	if (errorMsg != NULL) {
+	    Tcl_AppendResult(interp, " (", errorMsg, ")", NULL);
+	}
     }
     return NULL;
 }
@@ -2633,9 +2638,63 @@ static int
 CreateSocketAddress(
     struct sockaddr_in *sockaddrPtr,	/* Socket address */
     const char *host,			/* Host. NULL implies INADDR_ANY */
-    int port)				/* Port number */
+    int port,				/* Port number */
+    int willBind,			/* Is this an address to bind() to or
+					 * to connect() to? */
+    const char **errorMsgPtr)		/* Place to store the error message
+					 * detail, if available. */
 {
-    struct hostent *hostent;		/* Host database entry */
+#ifdef HAVE_GETADDRINFO
+    struct addrinfo hints, *resPtr = NULL;
+    int result;
+
+    if (host == NULL) {
+	sockaddrPtr->sin_family = AF_INET;
+	sockaddrPtr->sin_addr.s_addr = INADDR_ANY;
+    addPort:
+	sockaddrPtr->sin_port = htons((unsigned short) (port & 0xFFFF));
+	return 1;
+    }
+
+    (void) memset(&hints, 0, sizeof(struct addrinfo));
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_STREAM;
+    if (willBind) {
+	hints.ai_flags |= AI_PASSIVE;
+    }
+
+    /*
+     * Note that getaddrinfo() *is* thread-safe. If a platform doesn't get
+     * that right, it shouldn't use this part of the code.
+     */
+
+    result = getaddrinfo(host, NULL, &hints, &resPtr);
+    if (result == 0) {
+	memcpy(sockaddrPtr, resPtr->ai_addr, sizeof(struct sockaddr_in));
+	freeaddrinfo(resPtr);
+	goto addPort;
+    }
+
+    /*
+     * Ought to use gai_strerror() here...
+     */
+
+    switch (result) {
+    case EAI_NONAME:
+    case EAI_SERVICE:
+    case EAI_ADDRFAMILY:
+    case EAI_NODATA:
+	*errorMsgPtr = gai_strerror(result);
+	errno = EHOSTUNREACH;
+	return 0;
+    case EAI_SYSTEM:
+	return 0;
+    default:
+	*errorMsgPtr = gai_strerror(result);
+	errno = ENXIO;
+	return 0;
+    }
+#else /* !HAVE_GETADDRINFO */
     struct in_addr addr;		/* For 64/32 bit madness */
 
     (void) memset(sockaddrPtr, '\0', sizeof(struct sockaddr_in));
@@ -2644,10 +2703,15 @@ CreateSocketAddress(
     if (host == NULL) {
 	addr.s_addr = INADDR_ANY;
     } else {
+	struct hostent *hostent;	/* Host database entry */
 	Tcl_DString ds;
 	const char *native;
 
-	native = Tcl_UtfToExternalDString(NULL, host, -1, &ds);
+	if (host == NULL) {
+	    native = NULL;
+	} else {
+	    native = Tcl_UtfToExternalDString(NULL, host, -1, &ds);
+	}
 	addr.s_addr = inet_addr(native);		/* INTL: Native. */
 
 	/*
@@ -2656,8 +2720,11 @@ CreateSocketAddress(
 	 */
 
 	if (addr.s_addr == 0xFFFFFFFF) {
-	    hostent = gethostbyname(native);		/* INTL: Native. */
-	    if (hostent == NULL) {
+	    hostent = TclpGetHostByName(native);	/* INTL: Native. */
+	    if (hostent != NULL) {
+		memcpy(&addr, hostent->h_addr_list[0],
+			(size_t) hostent->h_length);
+	    } else {
 #ifdef	EHOSTUNREACH
 		errno = EHOSTUNREACH;
 #else /* !EHOSTUNREACH */
@@ -2665,11 +2732,14 @@ CreateSocketAddress(
 		errno = ENXIO;
 #endif /* ENXIO */
 #endif /* EHOSTUNREACH */
-		Tcl_DStringFree(&ds);
+		if (native != NULL) {
+		    Tcl_DStringFree(&ds);
+		}
 		return 0;	/* Error. */
 	    }
-	    memcpy(&addr, (void *) hostent->h_addr_list[0],
-		    (size_t) hostent->h_length);
+	}
+	if (native != NULL) {
+	    Tcl_DStringFree(&ds);
 	}
 	Tcl_DStringFree(&ds);
     }
@@ -2683,6 +2753,7 @@ CreateSocketAddress(
 
     sockaddrPtr->sin_addr.s_addr = addr.s_addr;
     return 1;			/* Success. */
+#endif /* HAVE_GETADDRINFO */
 }
 
 /*