From 74a16db9752f40656141adf47206b00037c0bce4 Mon Sep 17 00:00:00 2001
From: Yang Tse <yangsita@gmail.com>
Date: Tue, 28 Oct 2008 20:03:22 +0000
Subject: [PATCH] Initial attempt to detect at configuration time if the
getaddrinfo() function returns an addrinfo with an unfreeable ai_canonname
member ptr.
---
ares/configure.ac | 1 +
ares/m4/cares-functions.m4 | 75 ++++++++++++++++++++++++++++++++++++++
configure.ac | 1 +
m4/curl-functions.m4 | 75 ++++++++++++++++++++++++++++++++++++++
4 files changed, 152 insertions(+)
diff --git a/ares/configure.ac b/ares/configure.ac
index 9ef9078279..ac1ca1d0dd 100644
--- a/ares/configure.ac
+++ b/ares/configure.ac
@@ -555,6 +555,7 @@ CURL_CHECK_MSG_NOSIGNAL
CARES_CHECK_FUNC_GETADDRINFO
CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR
+CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_CANONNAME
CARES_CHECK_FUNC_GETHOSTNAME
CARES_CHECK_FUNC_GETSERVBYPORT_R
CARES_CHECK_FUNC_INET_NTOP
diff --git a/ares/m4/cares-functions.m4 b/ares/m4/cares-functions.m4
index 5117788e36..90a07846ae 100644
--- a/ares/m4/cares-functions.m4
+++ b/ares/m4/cares-functions.m4
@@ -440,6 +440,81 @@ AC_DEFUN([CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR], [
])
+dnl CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_CANONNAME
+dnl -------------------------------------------------
+dnl verify if the ai_canonname pointer member of the addrinfo
+dnl struct returned by function getaddrinfo is a pointer
+dnl which can actually be free()ed or not.
+
+AC_DEFUN([CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_CANONNAME], [
+ AC_REQUIRE([CARES_CHECK_FUNC_GETADDRINFO])dnl
+ AC_REQUIRE([CARES_INCLUDES_STRING])dnl
+ #
+ if test "$ac_cv_func_getaddrinfo" = "yes"; then
+ AC_MSG_CHECKING([if getaddrinfo returns unfreeable ai_canonname])
+ dnl only do runtime verification when not cross-compiling
+ if test "x$cross_compiling" != "xyes"; then
+ AC_RUN_IFELSE([
+ AC_LANG_PROGRAM([[
+ $cares_includes_ws2tcpip
+ $cares_includes_stdlib
+ $cares_includes_sys_socket
+ $cares_includes_netdb
+ $cares_includes_string
+ ]],[[
+ char tmp_canonname[80];
+ char *ai_canonname, *freed_ptr;
+ struct addrinfo hints;
+ struct addrinfo *ai = 0;
+ int error;
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_flags = AI_NUMERICHOST|AI_CANONNAME;
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+ error = getaddrinfo("127.0.0.1", 0, &hints, &ai);
+ if(error || !ai)
+ /* should not happen, same test already succeeded, */
+ /* assume that returned ai_canonname not unfreeable. */
+ exit(0);
+
+ memset(&tmp_canonname, 1, sizeof(tmp_canonname));
+ /* attempt to free ai_canonname pointer */
+ freed_ptr = ai_canonname = ai->ai_canonname;
+ /* seg-fault free'ing an unfreeable ptr would be */
+ /* nice, if this happen exit code will be non-zero. */
+ free(ai_canonname);
+ /* attempt to write free'ed memory */
+ freed_ptr[0] = 'x';
+ /* attempt to reuse and clear free'ed memory */
+ ai_canonname = calloc(1, sizeof(tmp_canonname));
+ /* attempt to read free'ed memory */
+ tmp_canonname[0] = freed_ptr[0];
+ /* verify if everithing has worked */
+ if(tmp_canonname[0] == 'x')
+ /* ai_canonname might be unfreeable, ouch! */
+ exit(1);
+ else
+ /* ai_canonname is certainly freeable */
+ exit(0);
+ ]])
+ ],[
+ dnl exit code was zero, getaddrinfo behaves nicely.
+ AC_MSG_RESULT([no])
+ ],[
+ dnl exit code wasn't zero, getaddrinfo returns unfreeable ptr.
+ AC_MSG_RESULT([yes])
+ AC_DEFINE_UNQUOTED(HAVE_GETADDRINFO_UNFREEABLE_AI_CANONNAME, 1,
+ [Define to 1 if getaddrinfo returns unfreeable ai_addr pointer.])
+ ])
+ else
+ dnl for cross-compiling a static check would be nice.
+ AC_MSG_RESULT([unknown])
+ fi
+ fi
+])
+
+
dnl CARES_CHECK_FUNC_GETHOSTNAME
dnl -------------------------------------------------
dnl Verify if gethostname is available, prototyped, and
diff --git a/configure.ac b/configure.ac
index 7f687b8f9e..5b462f5b2d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2018,6 +2018,7 @@ CURL_CHECK_FUNC_FDOPEN
CURL_CHECK_FUNC_FTRUNCATE
CURL_CHECK_FUNC_GETADDRINFO
CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR
+CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_CANONNAME
CURL_CHECK_FUNC_GETHOSTBYADDR_R
CURL_CHECK_FUNC_GETHOSTBYNAME_R
CURL_CHECK_FUNC_GETHOSTNAME
diff --git a/m4/curl-functions.m4 b/m4/curl-functions.m4
index e1bb9f4c82..2f06b571fe 100644
--- a/m4/curl-functions.m4
+++ b/m4/curl-functions.m4
@@ -793,6 +793,81 @@ AC_DEFUN([CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR], [
])
+dnl CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_CANONNAME
+dnl -------------------------------------------------
+dnl verify if the ai_canonname pointer member of the addrinfo
+dnl struct returned by function getaddrinfo is a pointer
+dnl which can actually be free()ed or not.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_CANONNAME], [
+ AC_REQUIRE([CURL_CHECK_FUNC_GETADDRINFO])dnl
+ AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+ #
+ if test "$ac_cv_func_getaddrinfo" = "yes"; then
+ AC_MSG_CHECKING([if getaddrinfo returns unfreeable ai_canonname])
+ dnl only do runtime verification when not cross-compiling
+ if test "x$cross_compiling" != "xyes"; then
+ AC_RUN_IFELSE([
+ AC_LANG_PROGRAM([[
+ $curl_includes_ws2tcpip
+ $curl_includes_stdlib
+ $curl_includes_sys_socket
+ $curl_includes_netdb
+ $curl_includes_string
+ ]],[[
+ char tmp_canonname[80];
+ char *ai_canonname, *freed_ptr;
+ struct addrinfo hints;
+ struct addrinfo *ai = 0;
+ int error;
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_flags = AI_NUMERICHOST|AI_CANONNAME;
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+ error = getaddrinfo("127.0.0.1", 0, &hints, &ai);
+ if(error || !ai)
+ /* should not happen, same test already succeeded, */
+ /* assume that returned ai_canonname not unfreeable. */
+ exit(0);
+
+ memset(&tmp_canonname, 1, sizeof(tmp_canonname));
+ /* attempt to free ai_canonname pointer */
+ freed_ptr = ai_canonname = ai->ai_canonname;
+ /* seg-fault free'ing an unfreeable ptr would be */
+ /* nice, if this happen exit code will be non-zero. */
+ free(ai_canonname);
+ /* attempt to write free'ed memory */
+ freed_ptr[0] = 'x';
+ /* attempt to reuse and clear free'ed memory */
+ ai_canonname = calloc(1, sizeof(tmp_canonname));
+ /* attempt to read free'ed memory */
+ tmp_canonname[0] = freed_ptr[0];
+ /* verify if everithing has worked */
+ if(tmp_canonname[0] == 'x')
+ /* ai_canonname might be unfreeable, ouch! */
+ exit(1);
+ else
+ /* ai_canonname is certainly freeable */
+ exit(0);
+ ]])
+ ],[
+ dnl exit code was zero, getaddrinfo behaves nicely.
+ AC_MSG_RESULT([no])
+ ],[
+ dnl exit code wasn't zero, getaddrinfo returns unfreeable ptr.
+ AC_MSG_RESULT([yes])
+ AC_DEFINE_UNQUOTED(HAVE_GETADDRINFO_UNFREEABLE_AI_CANONNAME, 1,
+ [Define to 1 if getaddrinfo returns unfreeable ai_addr pointer.])
+ ])
+ else
+ dnl for cross-compiling a static check would be nice.
+ AC_MSG_RESULT([unknown])
+ fi
+ fi
+])
+
+
dnl CURL_CHECK_FUNC_GETHOSTBYADDR_R
dnl -------------------------------------------------
dnl Verify if gethostbyaddr_r is available, prototyped,
--
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