From 6425ebb60ed7a7bc0f1b49969ef384ad284215bc Mon Sep 17 00:00:00 2001
From: David Garske <david@wolfssl.com>
Date: Thu, 19 Nov 2015 13:36:21 -0800
Subject: [PATCH] Linux Kernel Module support using "--enable-linuxkm".

---
 .gitignore                   |  1 +
 configure.ac                 | 14 +++++++++++
 src/internal.c               | 12 ++++++++-
 src/wolfio.c                 | 48 ++++++++++++++++++++++++++++++------
 wolfcrypt/src/logging.c      |  5 +++-
 wolfcrypt/src/random.c       | 11 +++++++++
 wolfcrypt/src/wc_port.c      | 17 +++++++++++++
 wolfssl/internal.h           |  7 +++++-
 wolfssl/wolfcrypt/integer.h  |  6 ++++-
 wolfssl/wolfcrypt/memory.h   |  2 +-
 wolfssl/wolfcrypt/settings.h | 16 ++++++++++++
 wolfssl/wolfcrypt/types.h    | 34 ++++++++++++++++++-------
 wolfssl/wolfcrypt/wc_port.h  | 21 +++++++++++++---
 wolfssl/wolfio.h             |  5 ++++
 14 files changed, 175 insertions(+), 24 deletions(-)

diff --git a/.gitignore b/.gitignore
index 91b6af694..2d534cda7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,6 +17,7 @@ config.*
 *.suo
 *.sdf
 *.opensdf
+*.cmd
 ipch/
 build-aux/
 rpm/spec
diff --git a/configure.ac b/configure.ac
index 8a72025c1..bf9a5c8bc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3365,6 +3365,19 @@ then
 fi
 
 
+# Linux Kernel Module
+AC_ARG_ENABLE([linuxkm],
+    [  --enable-linuxkm        Enable Linux Kernel Module (default: disabled)],
+    [ ENABLED_LINUXKM=$enableval ],
+    [ ENABLED_LINUXKM=no ]
+    )
+
+if test "x$ENABLED_LINUXKM" = "xyes"
+then
+    AM_CFLAGS="$AM_CFLAGS -DWOLFSSL_LINUXKM"
+fi
+
+
 #valgrind
 AC_ARG_ENABLE([valgrind],
     [AS_HELP_STRING([--enable-valgrind],[Enable valgrind for unit tests (default: disabled)])],
@@ -5630,6 +5643,7 @@ echo "   * wolfSSH                     $ENABLED_WOLFSSH"
 echo "   * wolfSCEP                    $ENABLED_WOLFSCEP"
 echo "   * Secure Remote Password      $ENABLED_SRP"
 echo "   * Small Stack:                $ENABLED_SMALL_STACK"
+echo "   * Linux Kernel Module:        $ENABLED_LINUXKM"
 echo "   * valgrind unit tests:        $ENABLED_VALGRIND"
 echo "   * LIBZ:                       $ENABLED_LIBZ"
 echo "   * Examples:                   $ENABLED_EXAMPLES"
diff --git a/src/internal.c b/src/internal.c
index a666f63d4..b16ff32c5 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -71,7 +71,7 @@
 
 #if defined(DEBUG_WOLFSSL) || defined(SHOW_SECRETS) || \
     defined(CHACHA_AEAD_TEST) || defined(WOLFSSL_SESSION_EXPORT_DEBUG)
-    #ifndef NO_STDIO_FILESYSTEM
+    #if !defined(NO_STDIO_FILESYSTEM) && !defined(WOLFSSL_LINUXKM)
         #include <stdio.h>
     #endif
 #endif
@@ -7647,6 +7647,16 @@ ProtocolVersion MakeDTLSv1_2(void)
         return k_uptime_get() / 1000;
     }
 
+#elif defined(WOLFSSL_LINUXKM)
+    #include <linux/time.h>
+    #include <linux/ktime.h>
+    word32 LowResTimer(void)
+    {
+        struct timespec ts;
+        getnstimeofday(&ts);
+        return ts.tv_sec * 1000000000LL + ts.tv_nsec;
+    }
+
 #else
     /* Posix style time */
     #if !defined(USER_TIME) && !defined(USE_WOLF_TM)
diff --git a/src/wolfio.c b/src/wolfio.c
index 86107f40b..e00c87ea5 100644
--- a/src/wolfio.c
+++ b/src/wolfio.c
@@ -88,12 +88,16 @@ static WC_INLINE int TranslateReturnCode(int old, int sd)
     return old;
 }
 
-static WC_INLINE int wolfSSL_LastError(void)
+static WC_INLINE int wolfSSL_LastError(int err)
 {
+    (void)err; /* Suppress unused arg */
+
 #ifdef USE_WINDOWS_API
     return WSAGetLastError();
 #elif defined(EBSNET)
     return xn_getlasterror();
+#elif defined(WOLFSSL_LINUXKM)
+    return err; /* Return provided error value */
 #else
     return errno;
 #endif
@@ -214,12 +218,16 @@ int BioSend(WOLFSSL* ssl, char *buf, int sz, void *ctx)
  */
 int EmbedReceive(WOLFSSL *ssl, char *buf, int sz, void *ctx)
 {
-    int sd = *(int*)ctx;
     int recvd;
+#ifndef WOLFSSL_LINUXKM
+    int sd = *(int*)ctx;
+#else
+    struct socket *sd = (struct socket*)ctx;
+#endif
 
     recvd = wolfIO_Recv(sd, buf, sz, ssl->rflags);
     if (recvd < 0) {
-        int err = wolfSSL_LastError();
+        int err = wolfSSL_LastError(recvd);
         WOLFSSL_MSG("Embed Receive error");
 
         if (err == SOCKET_EWOULDBLOCK || err == SOCKET_EAGAIN) {
@@ -256,8 +264,12 @@ int EmbedReceive(WOLFSSL *ssl, char *buf, int sz, void *ctx)
  */
 int EmbedSend(WOLFSSL* ssl, char *buf, int sz, void *ctx)
 {
-    int sd = *(int*)ctx;
     int sent;
+#ifndef WOLFSSL_LINUXKM
+    int sd = *(int*)ctx;
+#else
+    struct socket *sd = (struct socket*)ctx;
+#endif
 
 #ifdef WOLFSSL_MAX_SEND_SZ
     if (sz > WOLFSSL_MAX_SEND_SZ)
@@ -266,7 +278,7 @@ int EmbedSend(WOLFSSL* ssl, char *buf, int sz, void *ctx)
 
     sent = wolfIO_Send(sd, buf, sz, ssl->wflags);
     if (sent < 0) {
-        int err = wolfSSL_LastError();
+        int err = wolfSSL_LastError(sent);
         WOLFSSL_MSG("Embed Send error");
 
         if (err == SOCKET_EWOULDBLOCK || err == SOCKET_EAGAIN) {
@@ -343,7 +355,7 @@ int EmbedReceiveFrom(WOLFSSL *ssl, char *buf, int sz, void *ctx)
     recvd = TranslateReturnCode(recvd, sd);
 
     if (recvd < 0) {
-        err = wolfSSL_LastError();
+        err = wolfSSL_LastError(recvd);
         WOLFSSL_MSG("Embed Receive From error");
 
         if (err == SOCKET_EWOULDBLOCK || err == SOCKET_EAGAIN) {
@@ -405,7 +417,7 @@ int EmbedSendTo(WOLFSSL* ssl, char *buf, int sz, void *ctx)
     sent = TranslateReturnCode(sent, sd);
 
     if (sent < 0) {
-        err = wolfSSL_LastError();
+        err = wolfSSL_LastError(sent);
         WOLFSSL_MSG("Embed Send To error");
 
         if (err == SOCKET_EWOULDBLOCK || err == SOCKET_EAGAIN) {
@@ -638,6 +650,28 @@ int EmbedGenerateCookie(WOLFSSL* ssl, byte *buf, int sz, void *ctx)
 #endif /* WOLFSSL_SESSION_EXPORT */
 #endif /* WOLFSSL_DTLS */
 
+#ifdef WOLFSSL_LINUXKM
+static int linuxkm_send(struct socket *socket, void *buf, int size,
+    unsigned int flags)
+{
+    int ret;
+    struct kvec vec = { .iov_base = buf, .iov_len = size };
+    struct msghdr msg = { .msg_flags = flags };
+    ret = kernel_sendmsg(socket, &msg, &vec, 1, size);
+    return ret;
+}
+
+static int linuxkm_recv(struct socket *socket, void *buf, int size,
+    unsigned int flags)
+{
+    int ret;
+    struct kvec vec = { .iov_base = buf, .iov_len = size };
+    struct msghdr msg = { .msg_flags = flags };
+    ret = kernel_recvmsg(socket, &msg, &vec, 1, size, msg.msg_flags);
+    return ret;
+}
+#endif /* WOLFSSL_LINUXKM */
+
 
 int wolfIO_Recv(SOCKET_T sd, char *buf, int sz, int rdFlags)
 {
diff --git a/wolfcrypt/src/logging.c b/wolfcrypt/src/logging.c
index da4dea5bd..8b53f77da 100644
--- a/wolfcrypt/src/logging.c
+++ b/wolfcrypt/src/logging.c
@@ -232,6 +232,8 @@ void WOLFSSL_TIME(int count)
     #include <android/log.h>
 #elif defined(WOLFSSL_XILINX)
     #include "xil_printf.h"
+#elif defined(WOLFSSL_LINUXKM)
+    #include <linux/kernel.h>
 #else
     #include <stdio.h>   /* for default printf stuff */
 #endif
@@ -265,7 +267,6 @@ static void wolfssl_log(const int logLevel, const char *const logMessage)
         fnDebugMsg("\r\n");
 #elif defined(MQX_USE_IO_OLD)
         fprintf(_mqxio_stderr, "%s\n", logMessage);
-
 #elif defined(WOLFSSL_APACHE_MYNEWT)
         LOG_DEBUG(&mynewt_log, LOG_MODULE_DEFAULT, "%s\n", logMessage);
 #elif defined(WOLFSSL_ESPIDF)
@@ -278,6 +279,8 @@ static void wolfssl_log(const int logLevel, const char *const logMessage)
         __android_log_print(ANDROID_LOG_VERBOSE, "[wolfSSL]", "%s", logMessage);
 #elif defined(WOLFSSL_XILINX)
         xil_printf("%s\r\n", logMessage);
+#elif defined(WOLFSSL_LINUXKM)
+        printk("%s\n", logMessage);
 #else
         fprintf(stderr, "%s\n", logMessage);
 #endif
diff --git a/wolfcrypt/src/random.c b/wolfcrypt/src/random.c
index c60906ce0..a473b887f 100644
--- a/wolfcrypt/src/random.c
+++ b/wolfcrypt/src/random.c
@@ -2387,6 +2387,17 @@ int wc_GenerateSeed(OS_Seed* os, byte* output, word32 sz)
             return 0;
         }
     #endif /* end WOLFSSL_ESPWROOM32 */
+ 
+#elif defined(WOLFSSL_LINUXKM)
+    #include <linux/random.h>
+    int wc_GenerateSeed(OS_Seed* os, byte* output, word32 sz)
+    {
+        (void)os;
+
+        get_random_bytes(output, sz);
+
+        return 0;
+    }
 
 #elif defined(WOLFSSL_RENESAS_TSIP)
 #if defined(WOLFSSL_RENESA_TSIP_IAREWRX)
diff --git a/wolfcrypt/src/wc_port.c b/wolfcrypt/src/wc_port.c
index 12716806d..ff679f153 100644
--- a/wolfcrypt/src/wc_port.c
+++ b/wolfcrypt/src/wc_port.c
@@ -2260,6 +2260,23 @@ time_t wiced_pseudo_unix_epoch_time(time_t * timer)
     #endif /* !NO_CRYPT_BENCHMARK */
 #endif /* WOLFSSL_TELIT_M2MB */
 
+
+#if defined(WOLFSSL_LINUXKM)
+
+unsigned long long GetUNIXCompatibleTime(void)
+{
+    struct timespec ts;
+    getnstimeofday(&ts);
+    return ts.tv_sec * 1000000000LL + ts.tv_nsec;
+}
+
+time_t XTIME(time_t * timer)
+{
+    return (time_t) (GetUNIXCompatibleTime() / 1000000000LL);
+}
+
+#endif /* WOLFSSL_LINUXKM */
+
 #endif /* !NO_ASN_TIME */
 
 #ifndef WOLFSSL_LEANPSK
diff --git a/wolfssl/internal.h b/wolfssl/internal.h
index 14aa5991e..1fe6d4252 100644
--- a/wolfssl/internal.h
+++ b/wolfssl/internal.h
@@ -186,7 +186,12 @@
     /* do nothing */
 #else
     #ifndef SINGLE_THREADED
-        #ifndef  WOLFSSL_USER_MUTEX
+        #if defined(WOLFSSL_LINUXKM)
+            #define WOLFSSL_KTHREADS
+            #include <linux/kthread.h>
+        #elif defined(WOLFSSL_USER_MUTEX)
+            /* do nothing */
+        #else
             #define WOLFSSL_PTHREADS
             #include <pthread.h>
         #endif
diff --git a/wolfssl/wolfcrypt/integer.h b/wolfssl/wolfcrypt/integer.h
index 2bd06ae2e..b1895d6cc 100644
--- a/wolfssl/wolfcrypt/integer.h
+++ b/wolfssl/wolfcrypt/integer.h
@@ -42,7 +42,11 @@
 #include <wolfssl/wolfcrypt/random.h>
 
 #ifndef CHAR_BIT
-    #include <limits.h>
+    #if defined(WOLFSSL_LINUXKM)
+        #include <linux/limits.h>
+    #else
+        #include <limits.h>
+    #endif
 #endif
 
 #include <wolfssl/wolfcrypt/mpi_class.h>
diff --git a/wolfssl/wolfcrypt/memory.h b/wolfssl/wolfcrypt/memory.h
index 688110b4e..d901b2f92 100644
--- a/wolfssl/wolfcrypt/memory.h
+++ b/wolfssl/wolfcrypt/memory.h
@@ -29,7 +29,7 @@
 #ifndef WOLFSSL_MEMORY_H
 #define WOLFSSL_MEMORY_H
 
-#ifndef STRING_USER
+#if !defined(STRING_USER) && !defined(WOLFSSL_LINUXKM)
 #include <stdlib.h>
 #endif
 #include <wolfssl/wolfcrypt/types.h>
diff --git a/wolfssl/wolfcrypt/settings.h b/wolfssl/wolfcrypt/settings.h
index f92b8d558..c373b89ec 100644
--- a/wolfssl/wolfcrypt/settings.h
+++ b/wolfssl/wolfcrypt/settings.h
@@ -215,6 +215,10 @@
 /* Uncomment next line if using Solaris OS*/
 /* #define WOLFSSL_SOLARIS */
 
+/* Uncomment next line if building for Linux Kernel Module */
+/* #define WOLFSSL_LINUXKM */
+
+
 #include <wolfssl/wolfcrypt/visibility.h>
 
 #ifdef WOLFSSL_USER_SETTINGS
@@ -2081,6 +2085,18 @@ extern void uITRON4_free(void *p) ;
 #endif
 
 
+#ifdef WOLFSSL_LINUXKM
+    #define NO_DEV_RANDOM
+    #define NO_WRITEV
+    #define NO_FILESYSTEM
+    #define SIZEOF_LONG         8
+    #define SIZEOF_LONG_LONG    8
+    #define CHAR_BIT            8
+    #define WOLFSSL_HAVE_MIN
+    #define WOLFSSL_HAVE_MAX
+#endif
+
+
 /* Place any other flags or defines here */
 
 #if defined(WOLFSSL_MYSQL_COMPATIBLE) && defined(_WIN32) \
diff --git a/wolfssl/wolfcrypt/types.h b/wolfssl/wolfcrypt/types.h
index 5301e161e..577f3a54d 100644
--- a/wolfssl/wolfcrypt/types.h
+++ b/wolfssl/wolfcrypt/types.h
@@ -351,6 +351,13 @@ decouple library dependencies with standard string, memory and so on.
         #define XFREE(p, h, t)       {void* xp = (p); if((xp)) free((xp));}
         #define XREALLOC(p, n, h, t) realloc((p), (size_t)(n))
         #endif
+
+    #elif defined(WOLFSSL_LINUXKM)
+        #include <linux/slab.h>
+        #define XMALLOC(s, h, t)     ((void)h, (void)t, kmalloc((s), GFP_KERNEL))
+        #define XFREE(p, h, t)       {void* xp = (p); if((xp)) kfree((xp));}
+        #define XREALLOC(p, n, h, t) krealloc((p), (n), GFP_KERNEL)
+
     #elif !defined(MICRIUM_MALLOC) && !defined(EBSNET) \
             && !defined(WOLFSSL_SAFERTOS) && !defined(FREESCALE_MQX) \
             && !defined(FREESCALE_KSDK_MQX) && !defined(FREESCALE_FREE_RTOS) \
@@ -442,12 +449,17 @@ decouple library dependencies with standard string, memory and so on.
         #define USE_WOLF_STRSEP
     #endif
 
-    #ifndef STRING_USER
-        #include <string.h>
-        #define XMEMCPY(d,s,l)    memcpy((d),(s),(l))
-        #define XMEMSET(b,c,l)    memset((b),(c),(l))
-        #define XMEMCMP(s1,s2,n)  memcmp((s1),(s2),(n))
-        #define XMEMMOVE(d,s,l)   memmove((d),(s),(l))
+	#ifndef STRING_USER
+        #if defined(WOLFSSL_LINUXKM)
+            #include <linux/string.h>
+        #else    
+    	    #include <string.h>
+        #endif
+
+	    #define XMEMCPY(d,s,l)    memcpy((d),(s),(l))
+	    #define XMEMSET(b,c,l)    memset((b),(c),(l))
+	    #define XMEMCMP(s1,s2,n)  memcmp((s1),(s2),(n))
+	    #define XMEMMOVE(d,s,l)   memmove((d),(s),(l))
 
         #define XSTRLEN(s1)       strlen((s1))
         #define XSTRNCPY(s1,s2,n) strncpy((s1),(s2),(n))
@@ -570,9 +582,13 @@ decouple library dependencies with standard string, memory and so on.
         #endif
     #endif /* OPENSSL_EXTRA */
 
-    #ifndef CTYPE_USER
-        #include <ctype.h>
-        #if defined(HAVE_ECC) || defined(HAVE_OCSP) || \
+	#ifndef CTYPE_USER
+        #if defined(WOLFSSL_LINUXKM)
+            #include <linux/ctype.h>
+        #else
+            #include <ctype.h>
+        #endif
+	    #if defined(HAVE_ECC) || defined(HAVE_OCSP) || \
             defined(WOLFSSL_KEY_GEN) || !defined(NO_DSA)
             #define XTOUPPER(c)     toupper((c))
             #define XISALPHA(c)     isalpha((c))
diff --git a/wolfssl/wolfcrypt/wc_port.h b/wolfssl/wolfcrypt/wc_port.h
index 08a1d2f9e..fadae9503 100644
--- a/wolfssl/wolfcrypt/wc_port.h
+++ b/wolfssl/wolfcrypt/wc_port.h
@@ -156,9 +156,14 @@
 
 #else
     #ifndef SINGLE_THREADED
-        #ifndef  WOLFSSL_USER_MUTEX
-            #define WOLFSSL_PTHREADS
-            #include <pthread.h>
+        #ifndef WOLFSSL_USER_MUTEX
+            #if defined(WOLFSSL_LINUXKM)
+                #define WOLFSSL_KTHREADS
+                #include <linux/kthread.h>
+            #else
+                #define WOLFSSL_PTHREADS
+                #include <pthread.h>
+            #endif
         #endif
     #endif
     #if (defined(OPENSSL_EXTRA) || defined(GOAHEAD_WS)) && \
@@ -242,6 +247,8 @@
         typedef M2MB_OS_MTX_HANDLE wolfSSL_Mutex;
     #elif defined(WOLFSSL_USER_MUTEX)
         /* typedef User_Mutex wolfSSL_Mutex; */
+    #elif defined(WOLFSSL_LINUXKM)
+        typedef struct mutex wolfSSL_Mutex;
     #else
         #error Need a mutex type in multithreaded mode
     #endif /* USE_WINDOWS_API */
@@ -664,6 +671,14 @@ WOLFSSL_API int wolfCrypt_Cleanup(void);
     #define WOLFSSL_GMTIME
     #define USE_WOLF_TM
 
+
+#elif defined(WOLFSSL_LINUXKM)
+    #include <linux/time.h>
+    #include <linux/ktime.h>
+
+    /* forward declaration */
+    struct tm* gmtime(const time_t* timer);
+    #define XGMTIME(c, t) gmtime((c))
 #else
     /* default */
     /* uses complete <time.h> facility */
diff --git a/wolfssl/wolfio.h b/wolfssl/wolfio.h
index ccbe6a2ad..32940dd64 100644
--- a/wolfssl/wolfio.h
+++ b/wolfssl/wolfio.h
@@ -94,6 +94,8 @@
     #elif defined(WOLFSSL_NUCLEUS_1_2)
         #include <externs.h>
         #include <errno.h>
+    #elif defined(WOLFSSL_LINUXKM)
+        #include <linux/net.h>
     #elif defined(WOLFSSL_ATMEL)
         #include "socket/include/socket.h"
     #elif defined(INTIME_RTOS)
@@ -295,6 +297,9 @@
 
     #define SEND_FUNCTION send
     #define RECV_FUNCTION recv
+#elif defined(WOLFSSL_LINUXKM)
+    #define SEND_FUNCTION linuxkm_send
+    #define RECV_FUNCTION linuxkm_recv
 #else
     #define SEND_FUNCTION send
     #define RECV_FUNCTION recv