Use sysctl for seeding on MacOS/BSD

Author: sipa

configure.ac

@@ -788,7 +788,7 @@ if test x$TARGET_OS = xdarwin; then
   AX_CHECK_LINK_FLAG([[-Wl,-dead_strip]], [LDFLAGS="$LDFLAGS -Wl,-dead_strip"])
 fi
 
-AC_CHECK_HEADERS([endian.h sys/endian.h byteswap.h stdio.h stdlib.h unistd.h strings.h sys/types.h sys/stat.h sys/select.h sys/prctl.h])
+AC_CHECK_HEADERS([endian.h sys/endian.h byteswap.h stdio.h stdlib.h unistd.h strings.h sys/types.h sys/stat.h sys/select.h sys/prctl.h sys/sysctl.h vm/vm_param.h sys/vmmeter.h sys/resources.h])
 
 # FD_ZERO may be dependent on a declaration of memcpy, e.g. in SmartOS
 # check that it fails to build without memcpy, then that it builds with
@@ -948,6 +948,18 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <unistd.h>
  [ AC_MSG_RESULT(no)]
 )
 
+AC_MSG_CHECKING(for sysctl)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>
+  #include <sys/sysctl.h>]],
+ [[ static const int name[2] = {CTL_KERN, KERN_VERSION};
+    #ifdef __linux__
+    #error "Don't use sysctl on Linux, it's deprecated even when it works"
+    #endif
+    sysctl(name, 2, nullptr, nullptr, nullptr, 0); ]])],
+ [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYSCTL, 1,[Define this symbol if the BSD sysctl() is available]) ],
+ [ AC_MSG_RESULT(no)]
+)
+
 AC_MSG_CHECKING(for sysctl KERN_ARND)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>
   #include <sys/sysctl.h>]],

src/randomenv.cpp

@@ -44,6 +44,18 @@
 #if HAVE_DECL_GETIFADDRS
 #include <ifaddrs.h>
 #endif
+#if HAVE_SYSCTL
+#include <sys/sysctl.h>
+#if HAVE_VM_VM_PARAM_H
+#include <vm/vm_param.h>
+#endif
+#if HAVE_SYS_RESOURCES_H
+#include <sys/resources.h>
+#endif
+#if HAVE_SYS_VMMETER_H
+#include <sys/vmmeter.h>
+#endif
+#endif
 
 //! Necessary on some platforms
 extern char** environ;
@@ -149,6 +161,23 @@ void AddPath(CSHA512& hasher, const char *path)
 }
 #endif
 
+#if HAVE_SYSCTL
+template<int... S>
+void AddSysctl(CSHA512& hasher)
+{
+    int CTL[sizeof...(S)] = {S...};
+    unsigned char buffer[65536];
+    size_t siz = 65536;
+    int ret = sysctl(CTL, sizeof...(S), buffer, &siz, nullptr, 0);
+    if (ret == 0 || (ret == -1 && errno == ENOMEM)) {
+        hasher << sizeof(CTL);
+        hasher.Write((const unsigned char*)CTL, sizeof(CTL));
+        if (siz > sizeof(buffer)) siz = sizeof(buffer);
+        hasher << siz;
+        hasher.Write(buffer, siz);
+    }
+}
+#endif
 
 } // namespace
 
@@ -217,6 +246,30 @@ void RandAddDynamicEnv(CSHA512& hasher)
     AddFile(hasher, "/proc/self/status");
 #endif
 
+#if HAVE_SYSCTL
+#  ifdef CTL_KERN
+#    if defined(KERN_PROC) && defined(KERN_PROC_ALL)
+    AddSysctl<CTL_KERN, KERN_PROC, KERN_PROC_ALL>(hasher);
+#    endif
+#  endif
+#  ifdef CTL_HW
+#    ifdef HW_DISKSTATS
+    AddSysctl<CTL_HW, HW_DISKSTATS>(hasher);
+#    endif
+#  endif
+#  ifdef CTL_VM
+#    ifdef VM_LOADAVG
+    AddSysctl<CTL_VM, VM_LOADAVG>(hasher);
+#    endif
+#    ifdef VM_TOTAL
+    AddSysctl<CTL_VM, VM_TOTAL>(hasher);
+#    endif
+#    ifdef VM_METER
+    AddSysctl<CTL_VM, VM_METER>(hasher);
+#    endif
+#  endif
+#endif
+
     // Stack and heap location
     void* addr = malloc(4097);
     hasher << &addr << addr;
@@ -299,8 +352,81 @@ void RandAddStaticEnv(CSHA512& hasher)
     AddFile(hasher, "/etc/resolv.conf");
     AddFile(hasher, "/etc/timezone");
     AddFile(hasher, "/etc/localtime");
+#endif
 
-    /* TODO: sysctl's for OSX to fetch information not available from /proc */
+    // For MacOS/BSDs, gather data through sysctl instead of /proc. Not all of these
+    // will exist on every system.
+#if HAVE_SYSCTL
+#  ifdef CTL_HW
+#    ifdef HW_MACHINE
+    AddSysctl<CTL_HW, HW_MACHINE>(hasher);
+#    endif
+#    ifdef HW_MODEL
+    AddSysctl<CTL_HW, HW_MODEL>(hasher);
+#    endif
+#    ifdef HW_NCPU
+    AddSysctl<CTL_HW, HW_NCPU>(hasher);
+#    endif
+#    ifdef HW_PHYSMEM
+    AddSysctl<CTL_HW, HW_PHYSMEM>(hasher);
+#    endif
+#    ifdef HW_USERMEM
+    AddSysctl<CTL_HW, HW_USERMEM>(hasher);
+#    endif
+#    ifdef HW_MACHINE_ARCH
+    AddSysctl<CTL_HW, HW_MACHINE_ARCH>(hasher);
+#    endif
+#    ifdef HW_REALMEM
+    AddSysctl<CTL_HW, HW_REALMEM>(hasher);
+#    endif
+#    ifdef HW_CPU_FREQ
+    AddSysctl<CTL_HW, HW_CPU_FREQ>(hasher);
+#    endif
+#    ifdef HW_BUS_FREQ
+    AddSysctl<CTL_HW, HW_BUS_FREQ>(hasher);
+#    endif
+#    ifdef HW_CACHELINE
+    AddSysctl<CTL_HW, HW_CACHELINE>(hasher);
+#    endif
+#  endif
+#  ifdef CTL_KERN
+#    ifdef KERN_BOOTFILE
+     AddSysctl<CTL_KERN, KERN_BOOTFILE>(hasher);
+#    endif
+#    ifdef KERN_BOOTTIME
+     AddSysctl<CTL_KERN, KERN_BOOTTIME>(hasher);
+#    endif
+#    ifdef KERN_CLOCKRATE
+     AddSysctl<CTL_KERN, KERN_CLOCKRATE>(hasher);
+#    endif
+#    ifdef KERN_HOSTID
+     AddSysctl<CTL_KERN, KERN_HOSTID>(hasher);
+#    endif
+#    ifdef KERN_HOSTUUID
+     AddSysctl<CTL_KERN, KERN_HOSTUUID>(hasher);
+#    endif
+#    ifdef KERN_HOSTNAME
+     AddSysctl<CTL_KERN, KERN_HOSTNAME>(hasher);
+#    endif
+#    ifdef KERN_OSRELDATE
+     AddSysctl<CTL_KERN, KERN_OSRELDATE>(hasher);
+#    endif
+#    ifdef KERN_OSRELEASE
+     AddSysctl<CTL_KERN, KERN_OSRELEASE>(hasher);
+#    endif
+#    ifdef KERN_OSREV
+     AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
+#    endif
+#    ifdef KERN_OSTYPE
+     AddSysctl<CTL_KERN, KERN_OSTYPE>(hasher);
+#    endif
+#    ifdef KERN_POSIX1
+     AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
+#    endif
+#    ifdef KERN_VERSION
+     AddSysctl<CTL_KERN, KERN_VERSION>(hasher);
+#    endif
+#  endif
 #endif
 
     // Env variables