diff --git a/CMakeLists.txt b/CMakeLists.txt index e2290af1..0a403880 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -164,6 +164,7 @@ CARES_FUNCTION_IN_LIBRARY (clock_gettime rt HAVE_LIBRT) # Look for necessary includes CHECK_INCLUDE_FILES (sys/types.h HAVE_SYS_TYPES_H) +CHECK_INCLUDE_FILES (sys/random.h HAVE_SYS_RANDOM_H) CHECK_INCLUDE_FILES (sys/socket.h HAVE_SYS_SOCKET_H) CHECK_INCLUDE_FILES (sys/sockio.h HAVE_SYS_SOCKIO_H) CHECK_INCLUDE_FILES (arpa/inet.h HAVE_ARPA_INET_H) @@ -281,6 +282,7 @@ CARES_EXTRAINCLUDE_IFSET (HAVE_STDLIB_H stdlib.h) CARES_EXTRAINCLUDE_IFSET (HAVE_STRING_H string.h) CARES_EXTRAINCLUDE_IFSET (HAVE_STRINGS_H strings.h) CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_IOCTL_H sys/ioctl.h) +CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_RANDOM_H sys/random.h) CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_SELECT_H sys/select.h) CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_SOCKET_H sys/socket.h) CARES_EXTRAINCLUDE_IFSET (HAVE_SYS_SOCKIO_H sys/sockio.h) @@ -365,6 +367,7 @@ CHECK_SYMBOL_EXISTS (gethostbyaddr "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETHOST CHECK_SYMBOL_EXISTS (gethostbyname "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETHOSTBYNAME) CHECK_SYMBOL_EXISTS (gethostname "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETHOSTNAME) CHECK_SYMBOL_EXISTS (getnameinfo "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETNAMEINFO) +CHECK_SYMBOL_EXISTS (getrandom "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETRANDOM) CHECK_SYMBOL_EXISTS (getservbyport_r "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETSERVBYPORT_R) CHECK_SYMBOL_EXISTS (getservbyname_r "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETSERVBYNAME_R) CHECK_SYMBOL_EXISTS (gettimeofday "${CMAKE_EXTRA_INCLUDE_FILES}" HAVE_GETTIMEOFDAY) @@ -562,6 +565,9 @@ ENDIF () IF (HAVE_SYS_TYPES_H) SET (CARES_HAVE_SYS_TYPES_H 1) ENDIF () +IF (HAVE_SYS_RANDOM_H) + SET (CARES_HAVE_SYS_RANDOM_H 1) +ENDIF() IF (HAVE_SYS_SOCKET_H) SET (CARES_HAVE_SYS_SOCKET_H 1) ENDIF() diff --git a/configure.ac b/configure.ac index 54e79d6e..2d65eb73 100644 --- a/configure.ac +++ b/configure.ac @@ -666,6 +666,7 @@ CARES_CHECK_FUNC_GETENV CARES_CHECK_FUNC_GETHOSTBYADDR CARES_CHECK_FUNC_GETHOSTBYNAME CARES_CHECK_FUNC_GETHOSTNAME +CARES_CHECK_FUNC_GETRANDOM CARES_CHECK_FUNC_GETSERVBYPORT_R CARES_CHECK_FUNC_INET_NET_PTON CARES_CHECK_FUNC_INET_NTOP diff --git a/include/ares_build.h.cmake b/include/ares_build.h.cmake index e847f17e..6bad69a2 100644 --- a/include/ares_build.h.cmake +++ b/include/ares_build.h.cmake @@ -8,6 +8,7 @@ * files. We need to include some dependent headers that may be system specific * for C-Ares */ #cmakedefine CARES_HAVE_SYS_TYPES_H +#cmakedefine CARES_HAVE_SYS_RANDOM_H #cmakedefine CARES_HAVE_SYS_SOCKET_H #cmakedefine CARES_HAVE_WINDOWS_H #cmakedefine CARES_HAVE_WS2TCPIP_H @@ -20,6 +21,10 @@ # include #endif +#ifdef CARES_HAVE_SYS_RANDOM_H +# include +#endif + #ifdef CARES_HAVE_SYS_SOCKET_H # include #endif diff --git a/m4/cares-functions.m4 b/m4/cares-functions.m4 index d4f4f994..ce8d2f90 100644 --- a/m4/cares-functions.m4 +++ b/m4/cares-functions.m4 @@ -186,6 +186,24 @@ cares_includes_stropts="\ ]) +dnl CARES_INCLUDES_SYS_RANDOM +dnl ------------------------------------------------- +dnl Set up variable with list of headers that must be +dnl included when sys/random.h is to be included. + +AC_DEFUN([CARES_INCLUDES_SYS_RANDOM], [ +cares_includes_sys_random="\ +/* includes start */ +#ifdef HAVE_SYS_RANDOM_H +# include +#endif +/* includes end */" + AC_CHECK_HEADERS( + sys/random.h, + [], [], [$cares_includes_sys_random]) +]) + + dnl CARES_INCLUDES_SYS_SOCKET dnl ------------------------------------------------- dnl Set up variable with list of headers that must be @@ -1520,6 +1538,90 @@ AC_DEFUN([CARES_CHECK_FUNC_GETHOSTNAME], [ fi ]) +dnl CARES_CHECK_FUNC_GETRANDOM +dnl ------------------------------------------------- +dnl Verify if getrandom is available, prototyped, and +dnl can be compiled. If all of these are true, and +dnl usage has not been previously disallowed with +dnl shell variable cares_disallow_getrandom, then +dnl HAVE_GETRANDOM will be defined. + +AC_DEFUN([CARES_CHECK_FUNC_GETRANDOM], [ + AC_REQUIRE([CARES_INCLUDES_SYS_RANDOM])dnl + # + tst_links_getrandom="unknown" + tst_proto_getrandom="unknown" + tst_compi_getrandom="unknown" + tst_allow_getrandom="unknown" + # + AC_MSG_CHECKING([if getrandom can be linked]) + AC_LINK_IFELSE([ + AC_LANG_FUNC_LINK_TRY([getrandom]) + ],[ + AC_MSG_RESULT([yes]) + tst_links_getrandom="yes" + ],[ + AC_MSG_RESULT([no]) + tst_links_getrandom="no" + ]) + # + if test "$tst_links_getrandom" = "yes"; then + AC_MSG_CHECKING([if getrandom is prototyped]) + AC_EGREP_CPP([getrandom],[ + $cares_includes_sys_random + ],[ + AC_MSG_RESULT([yes]) + tst_proto_getrandom="yes" + ],[ + AC_MSG_RESULT([no]) + tst_proto_getrandom="no" + ]) + fi + # + if test "$tst_proto_getrandom" = "yes"; then + AC_MSG_CHECKING([if getrandom is compilable]) + AC_COMPILE_IFELSE([ + AC_LANG_PROGRAM([[ + $cares_includes_sys_random + ]],[[ + if(0 != getrandom(0, 0, 0)) + return 1; + ]]) + ],[ + AC_MSG_RESULT([yes]) + tst_compi_getrandom="yes" + ],[ + AC_MSG_RESULT([no]) + tst_compi_getrandom="no" + ]) + fi + # + if test "$tst_compi_getrandom" = "yes"; then + AC_MSG_CHECKING([if getrandom usage allowed]) + if test "x$cares_disallow_getrandom" != "xyes"; then + AC_MSG_RESULT([yes]) + tst_allow_getrandom="yes" + else + AC_MSG_RESULT([no]) + tst_allow_getrandom="no" + fi + fi + # + AC_MSG_CHECKING([if getrandom might be used]) + if test "$tst_links_getrandom" = "yes" && + test "$tst_proto_getrandom" = "yes" && + test "$tst_compi_getrandom" = "yes" && + test "$tst_allow_getrandom" = "yes"; then + AC_MSG_RESULT([yes]) + AC_DEFINE_UNQUOTED(HAVE_GETRANDOM, 1, + [Define to 1 if you have the getrandom function.]) + ac_cv_func_getrandom="yes" + else + AC_MSG_RESULT([no]) + ac_cv_func_getrandom="no" + fi +]) + dnl CARES_CHECK_FUNC_GETSERVBYPORT_R dnl ------------------------------------------------- diff --git a/src/lib/ares_config.h.cmake b/src/lib/ares_config.h.cmake index 798820a3..db0dfe76 100644 --- a/src/lib/ares_config.h.cmake +++ b/src/lib/ares_config.h.cmake @@ -123,6 +123,9 @@ /* Define to 1 if you have the getnameinfo function. */ #cmakedefine HAVE_GETNAMEINFO +/* Define to 1 if you have the getrandom function. */ +#cmakedefine HAVE_GETRANDOM + /* Define to 1 if you have the getservbyport_r function. */ #cmakedefine HAVE_GETSERVBYPORT_R diff --git a/src/lib/ares_rand.c b/src/lib/ares_rand.c index 766c1e6e..f07d419d 100644 --- a/src/lib/ares_rand.c +++ b/src/lib/ares_rand.c @@ -155,7 +155,7 @@ static int ares__init_rand_engine(ares_rand_state *state) { memset(state, 0, sizeof(*state)); -#if defined(HAVE_ARC4RANDOM_BUF) || defined(_WIN32) +#if defined(HAVE_ARC4RANDOM_BUF) || defined(HAVE_GETRANDOM) || defined(_WIN32) state->type = ARES_RAND_OS; return 1; #elif defined(CARES_RANDOM_FILE) @@ -241,6 +241,21 @@ static void ares__rand_bytes(ares_rand_state *state, unsigned char *buf, size_t #elif defined(HAVE_ARC4RANDOM_BUF) arc4random_buf(buf, len); return; +#elif defined(HAVE_GETRANDOM) + while (1) { + size_t n = len - bytes_read; + /* getrandom() on Linux always succeeds and is never + * interrupted by a signal when requesting <= 256 bytes. + */ + ssize_t rv = getrandom(buf + bytes_read, n > 256 ? 256 : n, 0); + if (rv <= 0) + continue; /* Just retry. */ + + bytes_read += rv; + if (bytes_read == len) + return; + } + break; #else /* Shouldn't be possible to be here */ break; diff --git a/src/lib/setup_once.h b/src/lib/setup_once.h index a8cfe6be..4b0f9cec 100644 --- a/src/lib/setup_once.h +++ b/src/lib/setup_once.h @@ -91,6 +91,10 @@ # endif #endif +#ifdef HAVE_SYS_RANDOM_H +#include +#endif + #ifdef HAVE_SYS_SOCKET_H #include #endif