diff options
| -rw-r--r-- | acinclude.m4 | 42 | ||||
| -rw-r--r-- | ares/configure.ac | 2 | ||||
| -rw-r--r-- | ares/m4/cares-functions.m4 | 260 | ||||
| -rw-r--r-- | configure.ac | 8 | ||||
| -rw-r--r-- | m4/curl-functions.m4 | 260 |
5 files changed, 527 insertions, 45 deletions
diff --git a/acinclude.m4 b/acinclude.m4 index 8b10c0e50..93b47c819 100644 --- a/acinclude.m4 +++ b/acinclude.m4 @@ -2565,48 +2565,6 @@ AC_DEFUN([CURL_CHECK_FUNC_SELECT], [ ]) -dnl ************************************************************ -dnl check for working getaddrinfo() that works with AI_NUMERICHOST -dnl -AC_DEFUN([CURL_CHECK_WORKING_GETADDRINFO],[ - AC_CACHE_CHECK(for working getaddrinfo, ac_cv_working_getaddrinfo,[ - AC_TRY_RUN( [ -#include <netdb.h> -#include <sys/types.h> -#include <sys/socket.h> - -int main(void) -{ - struct addrinfo hints, *ai; - int error; - - memset(&hints, 0, sizeof(hints)); - hints.ai_flags = AI_NUMERICHOST; - hints.ai_family = AF_UNSPEC; - hints.ai_socktype = SOCK_STREAM; - error = getaddrinfo("127.0.0.1", "8080", &hints, &ai); - if (error) { - return 1; - } - return 0; -} -],[ - ac_cv_working_getaddrinfo="yes" -],[ - ac_cv_working_getaddrinfo="no" -],[ - ac_cv_working_getaddrinfo="yes" -])]) -if test "$ac_cv_working_getaddrinfo" = "yes"; then - AC_DEFINE(HAVE_GETADDRINFO, 1, [Define if getaddrinfo exists and works]) - AC_DEFINE(ENABLE_IPV6, 1, [Define if you want to enable IPv6 support]) - - IPV6_ENABLED=1 - AC_SUBST(IPV6_ENABLED) -fi -]) - - # This is only a temporary fix. This macro is here to replace the broken one # delivered by the automake project (including the 1.9.6 release). As soon as # they ship a working version we SHOULD remove this work-around. diff --git a/ares/configure.ac b/ares/configure.ac index 0550eaba8..9ef907827 100644 --- a/ares/configure.ac +++ b/ares/configure.ac @@ -553,6 +553,8 @@ CURL_CHECK_FUNC_RECVFROM CURL_CHECK_FUNC_SEND CURL_CHECK_MSG_NOSIGNAL +CARES_CHECK_FUNC_GETADDRINFO +CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR CARES_CHECK_FUNC_GETHOSTNAME CARES_CHECK_FUNC_GETSERVBYPORT_R CARES_CHECK_FUNC_INET_NTOP diff --git a/ares/m4/cares-functions.m4 b/ares/m4/cares-functions.m4 index 0aa51f60f..5117788e3 100644 --- a/ares/m4/cares-functions.m4 +++ b/ares/m4/cares-functions.m4 @@ -16,7 +16,7 @@ #*************************************************************************** # File version for 'aclocal' use. Keep it a single number. -# serial 10 +# serial 11 dnl CARES_INCLUDES_ARPA_INET @@ -112,6 +112,27 @@ cares_includes_string="\ ]) +dnl CARES_INCLUDES_SYS_SOCKET +dnl ------------------------------------------------- +dnl Set up variable with list of headers that must be +dnl included when sys/socket.h is to be included. + +AC_DEFUN([CARES_INCLUDES_SYS_SOCKET], [ +cares_includes_sys_socket="\ +/* includes start */ +#ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> +#endif +#ifdef HAVE_SYS_SOCKET_H +# include <sys/socket.h> +#endif +/* includes end */" + AC_CHECK_HEADERS( + sys/types.h sys/socket.h, + [], [], [$cares_includes_sys_socket]) +]) + + dnl CARES_INCLUDES_SYS_UIO dnl ------------------------------------------------- dnl Set up variable with list of headers that must be @@ -182,6 +203,243 @@ cares_includes_winsock2="\ ]) +dnl CARES_INCLUDES_WS2TCPIP +dnl ------------------------------------------------- +dnl Set up variable with list of headers that must be +dnl included when ws2tcpip.h is to be included. + +AC_DEFUN([CARES_INCLUDES_WS2TCPIP], [ +cares_includes_ws2tcpip="\ +/* includes start */ +#ifdef HAVE_WINDOWS_H +# ifndef WIN32_LEAN_AND_MEAN +# define WIN32_LEAN_AND_MEAN +# endif +# include <windows.h> +# ifdef HAVE_WINSOCK2_H +# include <winsock2.h> +# ifdef HAVE_WS2TCPIP_H +# include <ws2tcpip.h> +# endif +# endif +#endif +/* includes end */" + CURL_CHECK_HEADER_WINDOWS + CURL_CHECK_HEADER_WINSOCK2 + CURL_CHECK_HEADER_WS2TCPIP +]) + + +dnl CARES_CHECK_FUNC_GETADDRINFO +dnl ------------------------------------------------- +dnl Verify if getaddrinfo is available, prototyped, can +dnl be compiled and seems to work. If all of these are +dnl true, and usage has not been previously disallowed +dnl with shell variable cares_disallow_getaddrinfo, then +dnl HAVE_GETADDRINFO will be defined. + +AC_DEFUN([CARES_CHECK_FUNC_GETADDRINFO], [ + AC_REQUIRE([CARES_INCLUDES_WS2TCPIP])dnl + AC_REQUIRE([CARES_INCLUDES_STDLIB])dnl + AC_REQUIRE([CARES_INCLUDES_SYS_SOCKET])dnl + AC_REQUIRE([CARES_INCLUDES_NETDB])dnl + # + tst_links_getaddrinfo="unknown" + tst_proto_getaddrinfo="unknown" + tst_compi_getaddrinfo="unknown" + tst_works_getaddrinfo="unknown" + tst_allow_getaddrinfo="unknown" + # + AC_MSG_CHECKING([if getaddrinfo can be linked]) + AC_LINK_IFELSE([ + AC_LANG_PROGRAM([[ + $cares_includes_ws2tcpip + $cares_includes_sys_socket + $cares_includes_netdb + ]],[[ + if(0 != getaddrinfo(0, 0, 0, 0)) + return 1; + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_links_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_links_getaddrinfo="no" + ]) + # + if test "$tst_links_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo is prototyped]) + AC_EGREP_CPP([getaddrinfo],[ + $cares_includes_ws2tcpip + $cares_includes_sys_socket + $cares_includes_netdb + ],[ + AC_MSG_RESULT([yes]) + tst_proto_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_proto_getaddrinfo="no" + ]) + fi + # + if test "$tst_proto_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo is compilable]) + AC_COMPILE_IFELSE([ + AC_LANG_PROGRAM([[ + $cares_includes_ws2tcpip + $cares_includes_sys_socket + $cares_includes_netdb + ]],[[ + if(0 != getaddrinfo(0, 0, 0, 0)) + return 1; + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_compi_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_compi_getaddrinfo="no" + ]) + fi + # + dnl only do runtime verification when not cross-compiling + if test "x$cross_compiling" != "xyes" && + test "$tst_compi_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo seems to work]) + AC_RUN_IFELSE([ + AC_LANG_PROGRAM([[ + $cares_includes_ws2tcpip + $cares_includes_stdlib + $cares_includes_sys_socket + $cares_includes_netdb + ]],[[ + struct addrinfo hints; + struct addrinfo *ai = 0; + int error; + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_NUMERICHOST; + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + error = getaddrinfo("127.0.0.1", 0, &hints, &ai); + if(error || !ai) + exit(1); /* fail */ + else + exit(0); + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_works_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_works_getaddrinfo="no" + ]) + fi + # + if test "$tst_compi_getaddrinfo" = "yes" && + test "$tst_works_getaddrinfo" != "no"; then + AC_MSG_CHECKING([if getaddrinfo usage allowed]) + if test "x$cares_disallow_getaddrinfo" != "xyes"; then + AC_MSG_RESULT([yes]) + tst_allow_getaddrinfo="yes" + else + AC_MSG_RESULT([no]) + tst_allow_getaddrinfo="no" + fi + fi + # + AC_MSG_CHECKING([if getaddrinfo might be used]) + if test "$tst_links_getaddrinfo" = "yes" && + test "$tst_proto_getaddrinfo" = "yes" && + test "$tst_compi_getaddrinfo" = "yes" && + test "$tst_allow_getaddrinfo" = "yes" && + test "$tst_works_getaddrinfo" != "no"; then + AC_MSG_RESULT([yes]) + AC_DEFINE_UNQUOTED(HAVE_GETADDRINFO, 1, + [Define to 1 if you have a working getaddrinfo function.]) + ac_cv_func_getaddrinfo="yes" + else + AC_MSG_RESULT([no]) + ac_cv_func_getaddrinfo="no" + fi +]) + + +dnl CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR +dnl ------------------------------------------------- +dnl verify if the ai_addr pointer member of the addrinfo +dnl struct returned by function getaddrinfo is a pointer +dnl which can actually be free()ed or not. + +AC_DEFUN([CARES_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR], [ + AC_REQUIRE([CARES_CHECK_FUNC_GETADDRINFO])dnl + AC_REQUIRE([CARES_INCLUDES_STRING])dnl + # + if test "$ac_cv_func_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo returns unfreeable ai_addr]) + 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 + ]],[[ + struct sockaddr tmp_addr, *ai_addr, *freed_ptr; + struct addrinfo hints; + struct addrinfo *ai = 0; + int error; + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_NUMERICHOST; + 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_addr is not unfreeable. */ + exit(0); + + memset(&tmp_addr, 1, sizeof(tmp_addr)); + /* attempt to free ai_addr pointer */ + freed_ptr = ai_addr = ai->ai_addr; + /* seg-fault free'ing an unfreeable ptr would be */ + /* nice, if this happen exit code will be non-zero. */ + free(ai_addr); + /* attempt to write free'ed memory */ + freed_ptr->sa_family = 'x'; + /* attempt to reuse and clear free'ed memory */ + ai_addr = calloc(1, sizeof(struct sockaddr)); + /* attempt to read free'ed memory */ + tmp_addr = *freed_ptr; + /* verify if everithing has worked */ + if(tmp_addr.sa_family == 'x') + /* ai_addr might be unfreeable, ouch! */ + exit(1); + else + /* ai_addr 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_ADDR, 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 3fdf376bb..7f687b8f9 100644 --- a/configure.ac +++ b/configure.ac @@ -2016,6 +2016,8 @@ CURL_CHECK_MSG_NOSIGNAL CURL_CHECK_FUNC_ALARM CURL_CHECK_FUNC_FDOPEN CURL_CHECK_FUNC_FTRUNCATE +CURL_CHECK_FUNC_GETADDRINFO +CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR CURL_CHECK_FUNC_GETHOSTBYADDR_R CURL_CHECK_FUNC_GETHOSTBYNAME_R CURL_CHECK_FUNC_GETHOSTNAME @@ -2120,7 +2122,11 @@ dnl and get the types of five of its arguments. CURL_CHECK_FUNC_GETNAMEINFO if test "$ipv6" = "yes"; then - CURL_CHECK_WORKING_GETADDRINFO + if test "$ac_cv_func_getaddrinfo" = "yes"; then + AC_DEFINE(ENABLE_IPV6, 1, [Define if you want to enable IPv6 support]) + IPV6_ENABLED=1 + AC_SUBST(IPV6_ENABLED) + fi CURL_CHECK_NI_WITHSCOPEID fi diff --git a/m4/curl-functions.m4 b/m4/curl-functions.m4 index f2dd1e41f..e1bb9f4c8 100644 --- a/m4/curl-functions.m4 +++ b/m4/curl-functions.m4 @@ -22,7 +22,7 @@ #*************************************************************************** # File version for 'aclocal' use. Keep it a single number. -# serial 26 +# serial 27 dnl CURL_INCLUDES_ARPA_INET @@ -181,6 +181,27 @@ curl_includes_string="\ ]) +dnl CURL_INCLUDES_SYS_SOCKET +dnl ------------------------------------------------- +dnl Set up variable with list of headers that must be +dnl included when sys/socket.h is to be included. + +AC_DEFUN([CURL_INCLUDES_SYS_SOCKET], [ +curl_includes_sys_socket="\ +/* includes start */ +#ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> +#endif +#ifdef HAVE_SYS_SOCKET_H +# include <sys/socket.h> +#endif +/* includes end */" + AC_CHECK_HEADERS( + sys/types.h sys/socket.h, + [], [], [$curl_includes_sys_socket]) +]) + + dnl CURL_INCLUDES_SYS_UIO dnl ------------------------------------------------- dnl Set up variable with list of headers that must be @@ -280,6 +301,33 @@ curl_includes_winsock2="\ ]) +dnl CURL_INCLUDES_WS2TCPIP +dnl ------------------------------------------------- +dnl Set up variable with list of headers that must be +dnl included when ws2tcpip.h is to be included. + +AC_DEFUN([CURL_INCLUDES_WS2TCPIP], [ +curl_includes_ws2tcpip="\ +/* includes start */ +#ifdef HAVE_WINDOWS_H +# ifndef WIN32_LEAN_AND_MEAN +# define WIN32_LEAN_AND_MEAN +# endif +# include <windows.h> +# ifdef HAVE_WINSOCK2_H +# include <winsock2.h> +# ifdef HAVE_WS2TCPIP_H +# include <ws2tcpip.h> +# endif +# endif +#endif +/* includes end */" + CURL_CHECK_HEADER_WINDOWS + CURL_CHECK_HEADER_WINSOCK2 + CURL_CHECK_HEADER_WS2TCPIP +]) + + dnl CURL_CHECK_FUNC_ALARM dnl ------------------------------------------------- dnl Verify if alarm is available, prototyped, and @@ -535,6 +583,216 @@ AC_DEFUN([CURL_CHECK_FUNC_FTRUNCATE], [ ]) +dnl CURL_CHECK_FUNC_GETADDRINFO +dnl ------------------------------------------------- +dnl Verify if getaddrinfo is available, prototyped, can +dnl be compiled and seems to work. If all of these are +dnl true, and usage has not been previously disallowed +dnl with shell variable curl_disallow_getaddrinfo, then +dnl HAVE_GETADDRINFO will be defined. + +AC_DEFUN([CURL_CHECK_FUNC_GETADDRINFO], [ + AC_REQUIRE([CURL_INCLUDES_WS2TCPIP])dnl + AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl + AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl + AC_REQUIRE([CURL_INCLUDES_NETDB])dnl + # + tst_links_getaddrinfo="unknown" + tst_proto_getaddrinfo="unknown" + tst_compi_getaddrinfo="unknown" + tst_works_getaddrinfo="unknown" + tst_allow_getaddrinfo="unknown" + # + AC_MSG_CHECKING([if getaddrinfo can be linked]) + AC_LINK_IFELSE([ + AC_LANG_PROGRAM([[ + $curl_includes_ws2tcpip + $curl_includes_sys_socket + $curl_includes_netdb + ]],[[ + if(0 != getaddrinfo(0, 0, 0, 0)) + return 1; + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_links_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_links_getaddrinfo="no" + ]) + # + if test "$tst_links_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo is prototyped]) + AC_EGREP_CPP([getaddrinfo],[ + $curl_includes_ws2tcpip + $curl_includes_sys_socket + $curl_includes_netdb + ],[ + AC_MSG_RESULT([yes]) + tst_proto_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_proto_getaddrinfo="no" + ]) + fi + # + if test "$tst_proto_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo is compilable]) + AC_COMPILE_IFELSE([ + AC_LANG_PROGRAM([[ + $curl_includes_ws2tcpip + $curl_includes_sys_socket + $curl_includes_netdb + ]],[[ + if(0 != getaddrinfo(0, 0, 0, 0)) + return 1; + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_compi_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_compi_getaddrinfo="no" + ]) + fi + # + dnl only do runtime verification when not cross-compiling + if test "x$cross_compiling" != "xyes" && + test "$tst_compi_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo seems to work]) + AC_RUN_IFELSE([ + AC_LANG_PROGRAM([[ + $curl_includes_ws2tcpip + $curl_includes_stdlib + $curl_includes_sys_socket + $curl_includes_netdb + ]],[[ + struct addrinfo hints; + struct addrinfo *ai = 0; + int error; + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_NUMERICHOST; + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + error = getaddrinfo("127.0.0.1", 0, &hints, &ai); + if(error || !ai) + exit(1); /* fail */ + else + exit(0); + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_works_getaddrinfo="yes" + ],[ + AC_MSG_RESULT([no]) + tst_works_getaddrinfo="no" + ]) + fi + # + if test "$tst_compi_getaddrinfo" = "yes" && + test "$tst_works_getaddrinfo" != "no"; then + AC_MSG_CHECKING([if getaddrinfo usage allowed]) + if test "x$curl_disallow_getaddrinfo" != "xyes"; then + AC_MSG_RESULT([yes]) + tst_allow_getaddrinfo="yes" + else + AC_MSG_RESULT([no]) + tst_allow_getaddrinfo="no" + fi + fi + # + AC_MSG_CHECKING([if getaddrinfo might be used]) + if test "$tst_links_getaddrinfo" = "yes" && + test "$tst_proto_getaddrinfo" = "yes" && + test "$tst_compi_getaddrinfo" = "yes" && + test "$tst_allow_getaddrinfo" = "yes" && + test "$tst_works_getaddrinfo" != "no"; then + AC_MSG_RESULT([yes]) + AC_DEFINE_UNQUOTED(HAVE_GETADDRINFO, 1, + [Define to 1 if you have a working getaddrinfo function.]) + ac_cv_func_getaddrinfo="yes" + else + AC_MSG_RESULT([no]) + ac_cv_func_getaddrinfo="no" + fi +]) + + +dnl CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR +dnl ------------------------------------------------- +dnl verify if the ai_addr pointer member of the addrinfo +dnl struct returned by function getaddrinfo is a pointer +dnl which can actually be free()ed or not. + +AC_DEFUN([CURL_CHECK_FUNC_GETADDRINFO_UNFREEABLE_AI_ADDR], [ + AC_REQUIRE([CURL_CHECK_FUNC_GETADDRINFO])dnl + AC_REQUIRE([CURL_INCLUDES_STRING])dnl + # + if test "$ac_cv_func_getaddrinfo" = "yes"; then + AC_MSG_CHECKING([if getaddrinfo returns unfreeable ai_addr]) + 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 + ]],[[ + struct sockaddr tmp_addr, *ai_addr, *freed_ptr; + struct addrinfo hints; + struct addrinfo *ai = 0; + int error; + + memset(&hints, 0, sizeof(hints)); + hints.ai_flags = AI_NUMERICHOST; + 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_addr is not unfreeable. */ + exit(0); + + memset(&tmp_addr, 1, sizeof(tmp_addr)); + /* attempt to free ai_addr pointer */ + freed_ptr = ai_addr = ai->ai_addr; + /* seg-fault free'ing an unfreeable ptr would be */ + /* nice, if this happen exit code will be non-zero. */ + free(ai_addr); + /* attempt to write free'ed memory */ + freed_ptr->sa_family = 'x'; + /* attempt to reuse and clear free'ed memory */ + ai_addr = calloc(1, sizeof(struct sockaddr)); + /* attempt to read free'ed memory */ + tmp_addr = *freed_ptr; + /* verify if everithing has worked */ + if(tmp_addr.sa_family == 'x') + /* ai_addr might be unfreeable, ouch! */ + exit(1); + else + /* ai_addr 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_ADDR, 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, |