New wrapper around gethostbyaddr_r if the system has it, else a whole new

2002-04-16  Jeffrey Stedfast  <fejj@ximian.com>

	* e-host-utils.c (e_gethostbyaddr_r): New wrapper around
	gethostbyaddr_r if the system has it, else a whole new
	implementation.

svn path=/trunk/; revision=16483

1 files changed, 140 insertions, 77 deletions

diff --git a/e-util/e-host-utils.c b/e-util/e-host-utils.c
index ab1b1cc0d6..1649d14ece 100644
--- a/e-util/e-host-utils.c
+++ b/e-util/e-host-utils.c
@@ -28,10 +28,85 @@
 #include <stdio.h>
 #include <errno.h>
 
-#ifndef HAVE_GETHOSTBYNAME_R
+#if !defined (HAVE_GETHOSTBYNAME_R) || !defined (HAVE_GETHOSTBYADDR_R)
 G_LOCK_DEFINE_STATIC (gethost_mutex);
 #endif
 
+
+#define GETHOST_PROCESS(h, host, buf, buflen, herr) G_STMT_START {     \
+	int num_aliases = 0, num_addrs = 0;                            \
+	int req_length;                                                \
+	char *p;                                                       \
+	int i;                                                         \
+	                                                               \
+	/* check to make sure we have enough room in our buffer */     \
+	req_length = 0;                                                \
+	if (h->h_aliases) {                                            \
+		for (i = 0; h->h_aliases[i]; i++)                      \
+			req_length += strlen (h->h_aliases[i]) + 1;    \
+		num_aliases = i;                                       \
+	}                                                              \
+	                                                               \
+	if (h->h_addr_list) {                                          \
+		for (i = 0; h->h_addr_list[i]; i++)                    \
+			req_length += h->h_length;                     \
+		num_addrs = i;                                         \
+	}                                                              \
+	                                                               \
+	req_length += sizeof (char *) * (num_aliases + 1);             \
+	req_length += sizeof (char *) * (num_addrs + 1);               \
+	req_length += strlen (h->h_name) + 1;                          \
+	                                                               \
+	if (buflen < req_length) {                                     \
+		*herr = ERANGE;                                        \
+		G_UNLOCK (gethost_mutex);                              \
+		return ERANGE;                                         \
+	}                                                              \
+	                                                               \
+	/* we store the alias/addr pointers in the buffer */           \
+        /* their addresses here. */                                    \
+	p = buf;                                                       \
+	if (num_aliases) {                                             \
+		host->h_aliases = (char **) p;                         \
+		p += sizeof (char *) * (num_aliases + 1);              \
+	} else                                                         \
+		host->h_aliases = NULL;                                \
+                                                                       \
+	if (num_addrs) {                                               \
+		host->h_addr_list = (char **) p;                       \
+		p += sizeof (char *) * (num_addrs + 1);                \
+	} else                                                         \
+		host->h_addr_list = NULL;                              \
+	                                                               \
+	/* copy the host name into the buffer */                       \
+	host->h_name = p;                                              \
+	strcpy (p, h->h_name);                                         \
+	p += strlen (h->h_name) + 1;                                   \
+	host->h_addrtype = h->h_addrtype;                              \
+	host->h_length = h->h_length;                                  \
+	                                                               \
+	/* copy the aliases/addresses into the buffer */               \
+        /* and assign pointers into the hostent */                     \
+	*p = 0;                                                        \
+	if (num_aliases) {                                             \
+		for (i = 0; i < num_aliases; i++) {                    \
+			strcpy (p, h->h_aliases[i]);                   \
+			host->h_aliases[i] = p;                        \
+			p += strlen (h->h_aliases[i]);                 \
+		}                                                      \
+		host->h_aliases[num_aliases] = NULL;                   \
+	}                                                              \
+	                                                               \
+	if (num_addrs) {                                               \
+		for (i = 0; i < num_addrs; i++) {                      \
+			memcpy (p, h->h_addr_list[i], h->h_length);    \
+			host->h_addr_list[i] = p;                      \
+			p += h->h_length;                              \
+		}                                                      \
+		host->h_addr_list[num_addrs] = NULL;                   \
+	}                                                              \
+} G_STMT_END
+
 /**
  * e_gethostbyname_r:
  * @name: the host to resolve
@@ -48,109 +123,97 @@ G_LOCK_DEFINE_STATIC (gethost_mutex);
  **/
 int
 e_gethostbyname_r (const char *name, struct hostent *host,
-		   char *buf, int buflen, int *herr)
+		   char *buf, size_t buflen, int *herr)
 {
 #ifdef HAVE_GETHOSTBYNAME_R
 #ifdef GETHOSTBYNAME_R_FIVE_ARGS
-	if (gethostbyname_r(name, host, buf, buflen, herr))
+	if (gethostbyname_r (name, host, buf, buflen, herr))
 		return 0;
 	else
 		return errno;
 #else
 	struct hostent *hp;
 	int retval;
-
-	retval = gethostbyname_r(name, host, buf, buflen, &hp, herr);
+	
+	retval = gethostbyname_r (name, host, buf, buflen, &hp, herr);
 	if (hp != NULL)
 		*herr = 0;
 	return retval;
 #endif
 #else
-	int i;
-	char *p;
 	struct hostent *h;
-	int req_length;
-	int num_aliases = 0, num_addrs = 0;
-
+	
 	G_LOCK (gethost_mutex);
-
+	
 	h = gethostbyname (name);
-
+	
 	if (!h) {
 		*herr = h_errno;
 		G_UNLOCK (gethost_mutex);
 		return -1;
 	}
+	
+	GETHOST_PROCESS (h, host,buf, buflen, herr);
+	
+	G_UNLOCK (gethost_mutex);
+	
+	return 0;
+#endif
+}
 
-	/* check to make sure we have enough room in our buffer */
-	req_length = 0;
-	if (h->h_aliases) {
-		for (i = 0; h->h_aliases[i]; i ++)
-			req_length += strlen (h->h_aliases[i]) + 1;
-		num_aliases = i;
-	}
-	if (h->h_addr_list) {
-		for (i = 0; h->h_addr_list[i]; i ++)
-			req_length += h->h_length;
-		num_addrs = i;
-	}
-
-	req_length += sizeof (char*) * (num_aliases + 1);
-	req_length += sizeof (char*) * (num_addrs + 1);
-	req_length += strlen (h->h_name) + 1;
 
-	if (buflen < req_length) {
-		*herr = ERANGE;
-		G_UNLOCK (gethost_mutex);
-		return ERANGE;
-	}
-
-	/* we store the alias/addr pointers in the buffer - figure out
-           their addresses here. */
-	p = buf;
-	if (num_aliases) {
-		host->h_aliases = (char**)p;
-		p += sizeof (char*) * (num_aliases + 1);
-	}
-	else
-		host->h_aliases = NULL;
-	if (num_addrs) {
-		host->h_addr_list = (char**)p;
-		p += sizeof(char*) * (num_addrs + 1);
-	}
+/**
+ * e_gethostbyaddr_r:
+ * @addr: the addr to resolve
+ * @len: address length
+ * @type: AF type
+ * @host: a buffer pointing to a struct hostent to use for storage
+ * @buf: a buffer to use for hostname storage
+ * @buflen: the size of @buf
+ * @herr: a pointer to a variable to store an error code in
+ *
+ * Resolves the address @addr, in a hopefully-reentrant fashion.
+ *
+ * Return value: 0 on success, ERANGE if @buflen is too small,
+ * "something else" otherwise (in which case *@herr will be set to
+ * one of the gethostbyaddr() error codes).
+ **/
+int
+e_gethostbyaddr_r (const char *addr, int len, int type, struct hostent *host,
+		   char *buf, size_t buflen, int *herr)
+{
+#ifdef HAVE_GETHOSTBYADDR_R
+#ifdef GETHOSTBYADDR_R_SEVEN_ARGS
+	if (gethostbyaddr_r (addr, len, type, host, buf, buflen, herr))
+		return 0;
 	else
-		host->h_addr_list = NULL;
-
-	/* copy the host name into the buffer */
-	host->h_name = p;
-	strcpy (p, h->h_name);
-	p += strlen (h->h_name) + 1;
-	host->h_addrtype = h->h_addrtype;
-	host->h_length = h->h_length;
-
-	/* copy the aliases/addresses into the buffer, and assign the
-	   pointers into the hostent */
-	*p = 0;
-	if (num_aliases) {
-		for (i = 0; i < num_aliases; i ++) {
-			strcpy (p, h->h_aliases[i]);
-			host->h_aliases[i] = p;
-			p += strlen (h->h_aliases[i]);
-		}
-		host->h_aliases[num_aliases] = NULL;
-	}
-
-	if (num_addrs) {
-		for (i = 0; i < num_addrs; i ++) {
-			memcpy (p, h->h_addr_list[i], h->h_length);
-			host->h_addr_list[i] = p;
-			p += h->h_length;
-		}
-		host->h_addr_list[num_addrs] = NULL;
+		return errno;
+#else
+	struct hostent *hp;
+	int retval;
+	
+	retval = gethostbyaddr_r (addr, len, type, host, buf, buflen, &hp, herr);
+	if (hp != NULL)
+		*herr = 0;
+	return retval;
+#endif
+#else
+	struct hostent *h;
+	
+	G_LOCK (gethost_mutex);
+	
+	h = gethostbyaddr (addr, len, type);
+	
+	if (!h) {
+		*herr = h_errno;
+		G_UNLOCK (gethost_mutex);
+		return -1;
 	}
-
+	
+	GETHOST_PROCESS (h, host, buf, buflen, herr);
+	
 	G_UNLOCK (gethost_mutex);
-
+	
 	return 0;
 #endif
 }