summaryrefslogtreecommitdiff
path: root/ares_gethostbyaddr.c
diff options
context:
space:
mode:
authorAnas Nashif <anas.nashif@intel.com>2012-10-30 20:54:38 (GMT)
committerAnas Nashif <anas.nashif@intel.com>2012-10-30 20:54:38 (GMT)
commitb8e6c26b7b9608dffc84645f17fe4cf534af18dd (patch)
tree61d9fff2984aa043471a1c305cfc4c76d7a099fb /ares_gethostbyaddr.c
downloadc-ares-b8e6c26b7b9608dffc84645f17fe4cf534af18dd.zip
c-ares-b8e6c26b7b9608dffc84645f17fe4cf534af18dd.tar.gz
c-ares-b8e6c26b7b9608dffc84645f17fe4cf534af18dd.tar.bz2
Imported Upstream version 1.7.5upstream/1.7.5
Diffstat (limited to 'ares_gethostbyaddr.c')
-rw-r--r--ares_gethostbyaddr.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/ares_gethostbyaddr.c b/ares_gethostbyaddr.c
new file mode 100644
index 0000000..4b4c8a7
--- /dev/null
+++ b/ares_gethostbyaddr.c
@@ -0,0 +1,301 @@
+
+/* 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.
+ */
+#include "ares_setup.h"
+
+#ifdef HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#ifdef HAVE_NETDB_H
+# include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+# include <arpa/inet.h>
+#endif
+#ifdef HAVE_ARPA_NAMESER_H
+# include <arpa/nameser.h>
+#else
+# include "nameser.h"
+#endif
+#ifdef HAVE_ARPA_NAMESER_COMPAT_H
+# include <arpa/nameser_compat.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "ares.h"
+#include "inet_net_pton.h"
+#include "ares_platform.h"
+#include "ares_private.h"
+
+#ifdef WATT32
+#undef WIN32
+#endif
+
+struct addr_query {
+ /* Arguments passed to ares_gethostbyaddr() */
+ ares_channel channel;
+ struct ares_addr addr;
+ ares_host_callback callback;
+ void *arg;
+
+ const char *remaining_lookups;
+ int timeouts;
+};
+
+static void next_lookup(struct addr_query *aquery);
+static void addr_callback(void *arg, int status, int timeouts,
+ unsigned char *abuf, int alen);
+static void end_aquery(struct addr_query *aquery, int status,
+ struct hostent *host);
+static int file_lookup(struct ares_addr *addr, struct hostent **host);
+static void ptr_rr_name(char *name, const struct ares_addr *addr);
+
+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 && family != AF_INET6)
+ {
+ callback(arg, ARES_ENOTIMP, 0, NULL);
+ return;
+ }
+
+ if ((family == AF_INET && addrlen != sizeof(aquery->addr.addrV4)) ||
+ (family == AF_INET6 && addrlen != sizeof(aquery->addr.addrV6)))
+ {
+ callback(arg, ARES_ENOTIMP, 0, NULL);
+ return;
+ }
+
+ aquery = malloc(sizeof(struct addr_query));
+ if (!aquery)
+ {
+ callback(arg, ARES_ENOMEM, 0, NULL);
+ return;
+ }
+ aquery->channel = channel;
+ if (family == AF_INET)
+ memcpy(&aquery->addr.addrV4, addr, sizeof(aquery->addr.addrV4));
+ else
+ memcpy(&aquery->addr.addrV6, addr, sizeof(aquery->addr.addrV6));
+ aquery->addr.family = family;
+ aquery->callback = callback;
+ aquery->arg = arg;
+ aquery->remaining_lookups = channel->lookups;
+ aquery->timeouts = 0;
+
+ next_lookup(aquery);
+}
+
+static void next_lookup(struct addr_query *aquery)
+{
+ const char *p;
+ char name[128];
+ int status;
+ struct hostent *host;
+
+ for (p = aquery->remaining_lookups; *p; p++)
+ {
+ switch (*p)
+ {
+ case 'b':
+ ptr_rr_name(name, &aquery->addr);
+ 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);
+
+ /* this status check below previously checked for !ARES_ENOTFOUND,
+ but we should not assume that this single error code is the one
+ that can occur, as that is in fact no longer the case */
+ if (status == ARES_SUCCESS)
+ {
+ end_aquery(aquery, status, host);
+ return;
+ }
+ break;
+ }
+ }
+ end_aquery(aquery, ARES_ENOTFOUND, NULL);
+}
+
+static void addr_callback(void *arg, int status, int timeouts,
+ unsigned char *abuf, int alen)
+{
+ struct addr_query *aquery = (struct addr_query *) arg;
+ struct hostent *host;
+ size_t addrlen;
+
+ aquery->timeouts += timeouts;
+ if (status == ARES_SUCCESS)
+ {
+ if (aquery->addr.family == AF_INET)
+ {
+ addrlen = sizeof(aquery->addr.addrV4);
+ status = ares_parse_ptr_reply(abuf, alen, &aquery->addr.addrV4,
+ (int)addrlen, AF_INET, &host);
+ }
+ else
+ {
+ addrlen = sizeof(aquery->addr.addrV6);
+ status = ares_parse_ptr_reply(abuf, alen, &aquery->addr.addrV6,
+ (int)addrlen, AF_INET6, &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, aquery->timeouts, host);
+ if (host)
+ ares_free_hostent(host);
+ free(aquery);
+}
+
+static int file_lookup(struct ares_addr *addr, struct hostent **host)
+{
+ FILE *fp;
+ int status;
+ int error;
+
+#ifdef WIN32
+ char PATH_HOSTS[MAX_PATH];
+ win_platform platform;
+
+ PATH_HOSTS[0] = '\0';
+
+ platform = ares__getplatform();
+
+ if (platform == WIN_NT) {
+ char tmp[MAX_PATH];
+ HKEY hkeyHosts;
+
+ if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0, KEY_READ,
+ &hkeyHosts) == ERROR_SUCCESS)
+ {
+ DWORD dwLength = MAX_PATH;
+ RegQueryValueEx(hkeyHosts, DATABASEPATH, NULL, NULL, (LPBYTE)tmp,
+ &dwLength);
+ ExpandEnvironmentStrings(tmp, PATH_HOSTS, MAX_PATH);
+ RegCloseKey(hkeyHosts);
+ }
+ }
+ else if (platform == WIN_9X)
+ GetWindowsDirectory(PATH_HOSTS, MAX_PATH);
+ else
+ return ARES_ENOTFOUND;
+
+ strcat(PATH_HOSTS, WIN_PATH_HOSTS);
+
+#elif defined(WATT32)
+ extern const char *_w32_GetHostsFile (void);
+ const char *PATH_HOSTS = _w32_GetHostsFile();
+
+ if (!PATH_HOSTS)
+ return ARES_ENOTFOUND;
+#endif
+
+ fp = fopen(PATH_HOSTS, "r");
+ if (!fp)
+ {
+ error = ERRNO;
+ switch(error)
+ {
+ case ENOENT:
+ case ESRCH:
+ return ARES_ENOTFOUND;
+ default:
+ DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
+ error, strerror(error)));
+ DEBUGF(fprintf(stderr, "Error opening file: %s\n",
+ PATH_HOSTS));
+ *host = NULL;
+ return ARES_EFILE;
+ }
+ }
+ while ((status = ares__get_hostent(fp, addr->family, host)) == ARES_SUCCESS)
+ {
+ if (addr->family != (*host)->h_addrtype)
+ {
+ ares_free_hostent(*host);
+ continue;
+ }
+ if (addr->family == AF_INET)
+ {
+ if (memcmp((*host)->h_addr, &addr->addrV4,
+ sizeof(addr->addrV4)) == 0)
+ break;
+ }
+ else if (addr->family == AF_INET6)
+ {
+ if (memcmp((*host)->h_addr, &addr->addrV6,
+ sizeof(addr->addrV6)) == 0)
+ break;
+ }
+ ares_free_hostent(*host);
+ }
+ fclose(fp);
+ if (status == ARES_EOF)
+ status = ARES_ENOTFOUND;
+ if (status != ARES_SUCCESS)
+ *host = NULL;
+ return status;
+}
+
+static void ptr_rr_name(char *name, const struct ares_addr *addr)
+{
+ if (addr->family == AF_INET)
+ {
+ unsigned long laddr = ntohl(addr->addrV4.s_addr);
+ unsigned long a1 = (laddr >> 24UL) & 0xFFUL;
+ unsigned long a2 = (laddr >> 16UL) & 0xFFUL;
+ unsigned long a3 = (laddr >> 8UL) & 0xFFUL;
+ unsigned long a4 = laddr & 0xFFUL;
+ sprintf(name, "%lu.%lu.%lu.%lu.in-addr.arpa", a4, a3, a2, a1);
+ }
+ else
+ {
+ unsigned char *bytes = (unsigned char *)&addr->addrV6;
+ /* There are too many arguments to do this in one line using
+ * minimally C89-compliant compilers */
+ sprintf(name,
+ "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.",
+ bytes[15]&0xf, bytes[15] >> 4, bytes[14]&0xf, bytes[14] >> 4,
+ bytes[13]&0xf, bytes[13] >> 4, bytes[12]&0xf, bytes[12] >> 4,
+ bytes[11]&0xf, bytes[11] >> 4, bytes[10]&0xf, bytes[10] >> 4,
+ bytes[9]&0xf, bytes[9] >> 4, bytes[8]&0xf, bytes[8] >> 4);
+ sprintf(name+strlen(name),
+ "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.ip6.arpa",
+ bytes[7]&0xf, bytes[7] >> 4, bytes[6]&0xf, bytes[6] >> 4,
+ bytes[5]&0xf, bytes[5] >> 4, bytes[4]&0xf, bytes[4] >> 4,
+ bytes[3]&0xf, bytes[3] >> 4, bytes[2]&0xf, bytes[2] >> 4,
+ bytes[1]&0xf, bytes[1] >> 4, bytes[0]&0xf, bytes[0] >> 4);
+ }
+}