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-rw-r--r--ares/ares_gethostbyaddr.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/ares/ares_gethostbyaddr.c b/ares/ares_gethostbyaddr.c
new file mode 100644
index 000000000..7353f091b
--- /dev/null
+++ b/ares/ares_gethostbyaddr.c
@@ -0,0 +1,174 @@
+/* Copyright 1998 by the Massachusetts Institute of Technology.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose. It is provided "as is"
+ * without express or implied warranty.
+ */
+
+static const char rcsid[] = "$Id$";
+
+#include <sys/types.h>
+
+#ifdef WIN32
+#include "nameser.h"
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/nameser.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "ares.h"
+#include "ares_private.h"
+
+struct addr_query {
+ /* Arguments passed to ares_gethostbyaddr() */
+ ares_channel channel;
+ struct in_addr addr;
+ ares_host_callback callback;
+ void *arg;
+
+ const char *remaining_lookups;
+};
+
+static void next_lookup(struct addr_query *aquery);
+static void addr_callback(void *arg, int status, unsigned char *abuf,
+ int alen);
+static void end_aquery(struct addr_query *aquery, int status,
+ struct hostent *host);
+static int file_lookup(struct in_addr *addr, struct hostent **host);
+
+void ares_gethostbyaddr(ares_channel channel, const void *addr, int addrlen,
+ int family, ares_host_callback callback, void *arg)
+{
+ struct addr_query *aquery;
+
+ if (family != AF_INET || addrlen != sizeof(struct in_addr))
+ {
+ callback(arg, ARES_ENOTIMP, NULL);
+ return;
+ }
+
+ aquery = malloc(sizeof(struct addr_query));
+ if (!aquery)
+ {
+ callback(arg, ARES_ENOMEM, NULL);
+ return;
+ }
+ aquery->channel = channel;
+ memcpy(&aquery->addr, addr, sizeof(aquery->addr));
+ aquery->callback = callback;
+ aquery->arg = arg;
+ aquery->remaining_lookups = channel->lookups;
+
+ next_lookup(aquery);
+}
+
+static void next_lookup(struct addr_query *aquery)
+{
+ const char *p;
+ char name[64];
+ int a1, a2, a3, a4, status;
+ struct hostent *host;
+ unsigned long addr;
+
+ for (p = aquery->remaining_lookups; *p; p++)
+ {
+ switch (*p)
+ {
+ case 'b':
+ addr = ntohl(aquery->addr.s_addr);
+ a1 = addr >> 24;
+ a2 = (addr >> 16) & 0xff;
+ a3 = (addr >> 8) & 0xff;
+ a4 = addr & 0xff;
+ sprintf(name, "%d.%d.%d.%d.in-addr.arpa", a4, a3, a2, a1);
+ aquery->remaining_lookups = p + 1;
+ ares_query(aquery->channel, name, C_IN, T_PTR, addr_callback,
+ aquery);
+ return;
+ case 'f':
+ status = file_lookup(&aquery->addr, &host);
+ if (status != ARES_ENOTFOUND)
+ {
+ end_aquery(aquery, status, host);
+ return;
+ }
+ break;
+ }
+ }
+ end_aquery(aquery, ARES_ENOTFOUND, NULL);
+}
+
+static void addr_callback(void *arg, int status, unsigned char *abuf, int alen)
+{
+ struct addr_query *aquery = (struct addr_query *) arg;
+ struct hostent *host;
+
+ if (status == ARES_SUCCESS)
+ {
+ status = ares_parse_ptr_reply(abuf, alen, &aquery->addr,
+ sizeof(struct in_addr), AF_INET, &host);
+ end_aquery(aquery, status, host);
+ }
+ else if (status == ARES_EDESTRUCTION)
+ end_aquery(aquery, status, NULL);
+ else
+ next_lookup(aquery);
+}
+
+static void end_aquery(struct addr_query *aquery, int status,
+ struct hostent *host)
+{
+ aquery->callback(aquery->arg, status, host);
+ if (host)
+ ares_free_hostent(host);
+ free(aquery);
+}
+
+static int file_lookup(struct in_addr *addr, struct hostent **host)
+{
+ FILE *fp;
+ int status;
+
+#ifdef WIN32
+
+ char PATH_HOSTS[MAX_PATH];
+ if (IsNT) {
+ GetSystemDirectory(PATH_HOSTS, MAX_PATH);
+ strcat(PATH_HOSTS, PATH_HOSTS_NT);
+ } else {
+ GetWindowsDirectory(PATH_HOSTS, MAX_PATH);
+ strcat(PATH_HOSTS, PATH_HOSTS_9X);
+ }
+
+#endif
+
+ fp = fopen(PATH_HOSTS, "r");
+ if (!fp)
+ return ARES_ENOTFOUND;
+
+ while ((status = ares__get_hostent(fp, host)) == ARES_SUCCESS)
+ {
+ if (memcmp((*host)->h_addr, addr, sizeof(struct in_addr)) == 0)
+ break;
+ ares_free_hostent(*host);
+ }
+ fclose(fp);
+ if (status == ARES_EOF)
+ status = ARES_ENOTFOUND;
+ if (status != ARES_SUCCESS)
+ *host = NULL;
+ return status;
+}