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-rw-r--r--resolv/res_libc.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/resolv/res_libc.c b/resolv/res_libc.c
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+/*
+ * Copyright (c) 1995-1999 by 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.
+ */
+
+/* Define some functions that go int libc.so. */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static const char rcsid[] = "$Id$";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+
+#include <ctype.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#undef _res
+
+struct __res_state _res;
+
+/* This is the old res_init function. It has been moved from
+ res_data.c to this file since res_init should go into libc.so but
+ the rest of res_data not. */
+
+
+int
+res_init(void) {
+ extern int __res_vinit(res_state, int);
+
+ /*
+ * These three fields used to be statically initialized. This made
+ * it hard to use this code in a shared library. It is necessary,
+ * now that we're doing dynamic initialization here, that we preserve
+ * the old semantics: if an application modifies one of these three
+ * fields of _res before res_init() is called, res_init() will not
+ * alter them. Of course, if an application is setting them to
+ * _zero_ before calling res_init(), hoping to override what used
+ * to be the static default, we can't detect it and unexpected results
+ * will follow. Zero for any of these fields would make no sense,
+ * so one can safely assume that the applications were already getting
+ * unexpected results.
+ *
+ * _res.options is tricky since some apps were known to diddle the bits
+ * before res_init() was first called. We can't replicate that semantic
+ * with dynamic initialization (they may have turned bits off that are
+ * set in RES_DEFAULT). Our solution is to declare such applications
+ * "broken". They could fool us by setting RES_INIT but none do (yet).
+ */
+ if (!_res.retrans)
+ _res.retrans = RES_TIMEOUT;
+ if (!_res.retry)
+ _res.retry = 4;
+ if (!(_res.options & RES_INIT))
+ _res.options = RES_DEFAULT;
+
+ /*
+ * This one used to initialize implicitly to zero, so unless the app
+ * has set it to something in particular, we can randomize it now.
+ */
+ if (!_res.id)
+ _res.id = res_randomid();
+
+ return (__res_vinit(&_res, 1));
+}
+
+/* We need a resolver context - in unthreaded apps, this weak function
+ provides it. */
+
+struct __res_state *
+weak_const_function
+__res_state(void)
+{
+ return &_res;
+}