Add getentropy(2).

kernel/Makefile

@@ -123,6 +123,7 @@ pipe.o \
 poll.o \
 process.o \
 ptable.o \
+random.o \
 refcount.o \
 registers.o \
 resource.o \

kernel/include/sortix/kernel/random.h

@@ -0,0 +1,31 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+    This file is part of Sortix.
+
+    Sortix is free software: you can redistribute it and/or modify it under the
+    terms of the GNU General Public License as published by the Free Software
+    Foundation, either version 3 of the License, or (at your option) any later
+    version.
+
+    Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+    details.
+
+    You should have received a copy of the GNU General Public License along with
+    Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+    sortix/kernel/random.h
+    Kernel entropy gathering.
+
+*******************************************************************************/
+
+namespace Sortix {
+namespace Random {
+
+void Init();
+
+} // namespace Random
+} // namespace Sortix

kernel/include/sortix/syscall.h

@@ -172,6 +172,7 @@
 #define SYSCALL_GETPEERNAME 144
 #define SYSCALL_GETSOCKNAME 145
 #define SYSCALL_SHUTDOWN 146
-#define SYSCALL_MAX_NUM 147 /* index of highest constant + 1 */
+#define SYSCALL_GETENTROPY 147
+#define SYSCALL_MAX_NUM 148 /* index of highest constant + 1 */
 
 #endif

kernel/kernel.cpp

@@ -54,6 +54,7 @@
 #include <sortix/kernel/pci.h>
 #include <sortix/kernel/process.h>
 #include <sortix/kernel/ptable.h>
+#include <sortix/kernel/random.h>
 #include <sortix/kernel/refcount.h>
 #include <sortix/kernel/scheduler.h>
 #include <sortix/kernel/signal.h>
@@ -297,6 +298,9 @@ extern "C" void KernelInit(unsigned long magic, multiboot_info_t* bootinfo)
 	// Initialize the interrupt handler table and enable interrupts.
 	Interrupt::Init();
 
+	// Initialize entropy gathering.
+	Random::Init();
+
 	// Load the kernel symbols if provided by the bootloader.
 	do if ( bootinfo->flags & MULTIBOOT_INFO_ELF_SHDR )
 	{

kernel/random.cpp

@@ -0,0 +1,53 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2014.
+
+    This file is part of Sortix.
+
+    Sortix is free software: you can redistribute it and/or modify it under the
+    terms of the GNU General Public License as published by the Free Software
+    Foundation, either version 3 of the License, or (at your option) any later
+    version.
+
+    Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+    details.
+
+    You should have received a copy of the GNU General Public License along with
+    Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+    random.cpp
+    Kernel entropy gathering.
+
+*******************************************************************************/
+
+#include <errno.h>
+
+#include <sortix/kernel/copy.h>
+#include <sortix/kernel/random.h>
+#include <sortix/kernel/syscall.h>
+
+namespace Sortix {
+namespace Random {
+
+int sys_getentropy(void* user_buffer, size_t size)
+{
+	unsigned char buffer[256];
+	if ( sizeof(buffer) < size )
+		return errno = EIO, -1;
+	// TODO: SECURITY: We need to actually gather entropy and deliver it.
+	for ( size_t i = 0; i < size; i++ )
+		buffer[i] = i;
+	if ( !CopyToUser(user_buffer, buffer, size) )
+		return -1;
+	return 0;
+}
+
+void Init()
+{
+	Syscall::Register(SYSCALL_GETENTROPY, (void*) sys_getentropy);
+}
+
+} // namespace Random
+} // namespace Sortix

libc/Makefile

@@ -590,6 +590,7 @@ unistd/ftruncate.o \
 unistd/getcwd.o \
 unistd/getdomainname.o \
 unistd/getegid.o \
+unistd/getentropy.o \
 unistd/geteuid.o \
 unistd/getgid.o \
 unistd/gethostname.o \

libc/include/unistd.h

@@ -551,6 +551,7 @@ int dup3(int, int, int);
 int execvpe(const char*, char* const [], char* const []);
 char* get_current_dir_name(void);
 int getdomainname(char*, size_t);
+int getentropy(void*, size_t);
 int pipe2(int [2], int);
 void* sbrk(__intptr_t increment);
 typedef unsigned int useconds_t;

libc/unistd/getentropy.cpp

@@ -0,0 +1,34 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    unistd/getentropy.cpp
+    Read entropy into an user buffer.
+
+*******************************************************************************/
+
+#include <sys/syscall.h>
+
+#include <unistd.h>
+
+DEFN_SYSCALL2(int, sys_getentropy, SYSCALL_GETENTROPY, void*, size_t);
+
+extern "C" int getentropy(void* buffer, size_t size)
+{
+	return sys_getentropy(buffer, size);
+}