Some changes Bob suggested, including a lwres_context_t that is opaque, and is used to set options.

lib/lwres/include/lwres/lwres.h

@@ -23,6 +23,11 @@
 #include <isc/lang.h>
 #include <isc/int.h>
 
+/*
+ * Used to set various options such as timeout, authentication, etc
+ */
+typedef struct lwres_context lwres_context_t;
+
 #define LWRES_OPCODE_NOOP		0x00000000U
 typedef struct {
 	/* public */
@@ -42,9 +47,9 @@ typedef struct {
 typedef struct {
 	/* public */
 	isc_uint32_t		result;
-	unsigned char	       *real_name;
+	char		       *real_name;
 	unsigned int		naliases;
-	unsigned char	      **aliases;
+	char		      **aliases;
 	unsigned int		naddrs;
 	lwres_addr_t	      **addrs;
 	/* private */
@@ -57,9 +62,9 @@ typedef struct {
 typedef struct {
 	/* public */
 	isc_uint32_t		result;
-	unsigned char	       *real_name;
+	char		       *real_name;
 	unsigned int		naliases;
-	unsigned char	      **aliases;
+	char		      **aliases;
 	/* private */
 	unsigned int		buflen;
 	void		       *buffer;  /* must be last to keep alignment */
@@ -71,14 +76,20 @@ typedef struct {
 
 ISC_LANG_BEGINDECLS
 
+typedef void *(*lwres_malloc_t)(void *arg, unsigned int length);
+typedef void (*lwres_free_t)(void *arg, unsigned int length, void *mem);
+
 unsigned int
-lwres_getaddrsbyname(unsigned char *name, unsigned int addrtypes,
+lwres_getaddrsbyname(lwres_context_t *context,
+		     char *name, unsigned int addrtypes,
 		     lwres_getaddrsbyname_t **structp);
 /*
  * Makes a lwres call to look up all addresses associated with "name".
  *
  * Requires:
  *
+ *	context != NULL, and be a context returned via lwres_contextcreate().
+ *
  *	structp != NULL && *structp == NULL.
  *
  *	name != NULL, and be a null-terminated string.
@@ -97,12 +108,15 @@ lwres_getaddrsbyname(unsigned char *name, unsigned int addrtypes,
  */
 
 void
-lwres_freegetaddrsbyname(lwres_getaddrsbyname_t **structp);
+lwres_freegetaddrsbyname(lwres_context_t *context,
+			 lwres_getaddrsbyname_t **structp);
 /*
  * Frees any dynamically allocated memory for this structure.
  *
  * Requires:
  *
+ *	context != NULL, and be a context returned via lwres_contextcreate().
+ *
  *	structp != NULL && *structp != NULL.
  *
  * Ensures:
@@ -114,13 +128,16 @@ lwres_freegetaddrsbyname(lwres_getaddrsbyname_t **structp);
  */
 
 unsigned int
-lwres_getnamebyaddr(unsigned int addrlen, unsigned char *addr,
-		    unsigned int addrtype, lwres_getnamebyaddr_t **structp);
+lwres_getnamebyaddr(lwres_context_t *context, unsigned int addrtype,
+		    unsigned int addrlen, unsigned char *addr,
+		    lwres_getnamebyaddr_t **structp);
 /*
  * Makes a lwres call to look up the hostnames associated with the address.
  *
  * Requires:
  *
+ *	context != NULL, and be a context returned via lwres_contextcreate().
+ *
  *	structp != NULL && *structp == NULL.
  *
  *	addr != NULL, and points to an address of length "addrlen"
@@ -138,12 +155,15 @@ lwres_getnamebyaddr(unsigned int addrlen, unsigned char *addr,
  */
 
 void
-lwres_freegetnamebyaddr(lwres_getnamebyaddr_t **structp);
+lwres_freegetnamebyaddr(lwres_context_t *context,
+			lwres_getnamebyaddr_t **structp);
 /*
  * Frees any dynamically allocated memory for this structure.
  *
  * Requires:
  *
+ *	context != NULL, and be a context returned via lwres_contextcreate().
+ *
  *	structp != NULL && *structp != NULL.
  *
  * Ensures:
@@ -154,6 +174,40 @@ lwres_freegetnamebyaddr(lwres_getnamebyaddr_t **structp);
  *	system via free().
  */
 
+unsigned int
+lwres_contextcreate(lwres_context_t **contextp, void *arg,
+		    lwres_malloc_t malloc_function,
+		    lwres_free_t free_function);
+/*
+ * Allocated a lwres context.  This is used in all lwres calls.
+ *
+ * Memory management can be replaced here by passing in two functions.
+ * If one is non-NULL, they must both be non-NULL.  "arg" is passed to
+ * these functions.
+ *
+ * If they are NULL, the standard malloc() and free() will be used.
+ *
+ * Requires:
+ *
+ *	contextp != NULL && contextp == NULL.
+ *
+ *	
+ *
+ * Returns:
+ *
+ *	Returns 0 on success, non-zero on failure.
+ */
+
+void
+lwres_contextfree(lwres_context_t **contextp);
+/*
+ * Frees all memory associated with a lwres context.
+ *
+ * Requires:
+ *
+ *	contextp != NULL && contextp == NULL.
+ */
+
 ISC_LANG_ENDDECLS
 
 #endif /* LWRES_LWRES_H */

lib/lwres/lwres.c

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 1998, 1999  Internet Software Consortium.
+ * 
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ */
+
+/* XXXMLG */
+#define REQUIRE(x)
+
+#include <config.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <lwres/lwbuffer.h>
+#include <lwres/lwpacket.h>
+#include <lwres/lwres.h>
+
+static void *lwres_malloc(void *, size_t);
+static void lwres_free(void *, size_t, void *);
+
+/*
+ * Not all the attributes here are actually settable by the application at
+ * this time.
+ */
+struct lwres_context {
+	/*
+	 * Function pointers for allocating memory.
+	 */
+	lwres_malloc_t		malloc;
+	lwres_free_t		free;
+	void		       *arg;
+};
+
+unsigned int
+lwres_contextcreate(lwres_context_t **contextp, void *arg,
+		    lwres_malloc_t malloc_function,
+		    lwres_free_t free_function)
+{
+	lwres_context_t *context;
+
+	if (malloc_function == NULL) {
+		malloc_function = lwres_malloc;
+		free_function = lwres_free;
+	}
+
+	context = malloc_function(arg, sizeof(lwres_context_t));
+	if (context == NULL) {
+		errno = ENOMEM;
+		return (-1);
+	}
+
+	context->free = lwres_free;
+	context->malloc = lwres_malloc;
+	context->arg = arg;
+
+	*contextp = context;
+	return (0);
+}
+
+void
+lwres_contextfree(lwres_context_t **contextp)
+{
+	lwres_context_t *context;
+
+	context = *contextp;
+	*contextp = NULL;
+
+	/* This is always allocated via malloc() for now... */
+	context->free(context->arg, sizeof(lwres_context_t), context);
+}
+
+unsigned int
+lwres_getaddrsbyname(lwres_context_t *contextp,
+		     char *name, unsigned int addrtypes,
+		     lwres_getaddrsbyname_t **structp)
+{
+}
+
+void
+lwres_freegetaddrsbyname(lwres_context_t *contextp,
+			 lwres_getaddrsbyname_t **structp)
+{
+}
+
+unsigned int
+lwres_getnamebyaddr(lwres_context_t *contextp, unsigned int addrtype,
+		    unsigned int addrlen, unsigned char *addr,
+		    lwres_getnamebyaddr_t **structp)
+{
+}
+
+void
+lwres_freegetnamebyaddr(lwres_context_t *contextp,
+			lwres_getnamebyaddr_t **structp)
+{
+}
+
+static void *
+lwres_malloc(void *arg, size_t len)
+{
+	(void)arg;
+
+	return (malloc(len));
+}
+
+static void
+lwres_free(void *arg, size_t len, void *mem)
+{
+	(void)arg;
+	(void)len;
+
+	free(mem);
+}