Add basic math extension functions (#2123)

osquery/sql/CMakeLists.txt

@@ -4,6 +4,7 @@ ADD_OSQUERY_LIBRARY(TRUE osquery_sql
 
 ADD_OSQUERY_LIBRARY(FALSE osquery_sql_internal
   sqlite_util.cpp
+  sqlite_math.cpp
   virtual_table.cpp
 )
 

osquery/sql/sqlite_math.cpp

@@ -0,0 +1,205 @@
+/*
+ *  Copyright (c) 2014-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ *
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <math.h>
+#include <string.h>
+
+#include <functional>
+
+#include <sqlite3.h>
+
+namespace osquery {
+
+using DoubleDoubleFunction = std::function<double(double)>;
+
+/**
+ * @brief Call a math function that takes a double and returns a double.
+ */
+static void callDoubleFunc(sqlite3_context *context,
+                           int argc,
+                           sqlite3_value **argv,
+                           DoubleDoubleFunction f) {
+  double rVal = 0.0, val;
+  assert(argc == 1);
+  switch (sqlite3_value_type(argv[0])) {
+  case SQLITE_NULL:
+    sqlite3_result_null(context);
+    break;
+  default:
+    rVal = sqlite3_value_double(argv[0]);
+    errno = 0;
+    val = f(rVal);
+    if (errno == 0) {
+      sqlite3_result_double(context, val);
+    } else {
+      sqlite3_result_error(context, strerror(errno), errno);
+    }
+    break;
+  }
+}
+
+static void sinFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, sin);
+}
+
+static void cosFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, cos);
+}
+
+static void tanFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, tan);
+}
+
+static void asinFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, asin);
+}
+
+static void acosFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, acos);
+}
+
+static void atanFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, atan);
+}
+
+static double cot(double x) { return 1.0 / tan(x); }
+
+static void cotFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, cot);
+}
+
+static void logFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, log);
+}
+
+static void log10Func(sqlite3_context *context,
+                      int argc,
+                      sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, log10);
+}
+
+static void sqrtFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, sqrt);
+}
+
+static void expFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, exp);
+}
+
+static void powerFunc(sqlite3_context *context,
+                      int argc,
+                      sqlite3_value **argv) {
+  double r1 = 0.0;
+  double r2 = 0.0;
+  double val;
+
+  assert(argc == 2);
+
+  if (sqlite3_value_type(argv[0]) == SQLITE_NULL ||
+      sqlite3_value_type(argv[1]) == SQLITE_NULL) {
+    sqlite3_result_null(context);
+  } else {
+    r1 = sqlite3_value_double(argv[0]);
+    r2 = sqlite3_value_double(argv[1]);
+    errno = 0;
+    val = pow(r1, r2);
+    if (errno == 0) {
+      sqlite3_result_double(context, val);
+    } else {
+      sqlite3_result_error(context, strerror(errno), errno);
+    }
+  }
+}
+
+static void callCastedDoubleFunc(sqlite3_context *context,
+                                 int argc,
+                                 sqlite3_value **argv,
+                                 DoubleDoubleFunction f) {
+  double rVal = 0.0;
+  assert(argc == 1);
+  switch (sqlite3_value_type(argv[0])) {
+  case SQLITE_INTEGER: {
+    int64_t iVal = sqlite3_value_int64(argv[0]);
+    sqlite3_result_int64(context, iVal);
+    break;
+  }
+  case SQLITE_NULL:
+    sqlite3_result_null(context);
+    break;
+  default:
+    rVal = sqlite3_value_double(argv[0]);
+    sqlite3_result_int64(context, (int64_t)f(rVal));
+    break;
+  }
+}
+
+static void ceilFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  callCastedDoubleFunc(context, argc, argv, ceil);
+}
+
+static void floorFunc(sqlite3_context *context,
+                      int argc,
+                      sqlite3_value **argv) {
+  callCastedDoubleFunc(context, argc, argv, floor);
+}
+
+/** Convert Degrees into Radians */
+static double deg2rad(double x) { return x * M_PI / 180.0; }
+
+/** Convert Radians into Degrees */
+static double rad2deg(double x) { return 180.0 * x / M_PI; }
+
+static void rad2degFunc(sqlite3_context *context,
+                        int argc,
+                        sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, rad2deg);
+}
+
+static void deg2radFunc(sqlite3_context *context,
+                        int argc,
+                        sqlite3_value **argv) {
+  callDoubleFunc(context, argc, argv, deg2rad);
+}
+
+static void piFunc(sqlite3_context *context, int argc, sqlite3_value **argv) {
+  sqlite3_result_double(context, M_PI);
+}
+
+struct FuncDef {
+  const char *zFunctionName;
+  int nArg;
+  void (*xFunc)(sqlite3_context *, int, sqlite3_value **);
+};
+
+void registerMathExtensions(sqlite3 *db) {
+  // This approach to adding non-standard Math functions was inspired by the
+  // somewhat deprecated/legacy work by Liam Healy from 2010 in the extension
+  // functions contribution.
+  static const struct FuncDef aFuncs[] = {
+      {"sqrt", 1, sqrtFunc},       {"acos", 1, acosFunc},
+      {"asin", 1, asinFunc},       {"atan", 1, atanFunc},
+      {"cos", 1, cosFunc},         {"sin", 1, sinFunc},
+      {"tan", 1, tanFunc},         {"cot", 1, cotFunc},
+      {"exp", 1, expFunc},         {"log", 1, logFunc},
+      {"log10", 1, log10Func},     {"power", 2, powerFunc},
+      {"ceil", 1, ceilFunc},       {"floor", 1, floorFunc},
+      {"degrees", 1, rad2degFunc}, {"radians", 1, deg2radFunc},
+      {"pi", 0, piFunc},
+  };
+
+  for (size_t i = 0; i < sizeof(aFuncs) / sizeof(struct FuncDef); i++) {
+    sqlite3_create_function(db, aFuncs[i].zFunctionName, aFuncs[i].nArg,
+                            SQLITE_UTF8, nullptr, aFuncs[i].xFunc, nullptr,
+                            nullptr);
+  }
+}
+}

osquery/sql/sqlite_util.cpp

@@ -35,49 +35,28 @@ using SQLiteDBInstanceRef = std::shared_ptr<SQLiteDBInstance>;
  *
  * Details of this map are defined at: http://www.sqlite.org/c3ref/c_abort.html
  */
+// clang-format off
 const std::map<int, std::string> kSQLiteReturnCodes = {
-    {0, "SQLITE_OK"},
-    {1, "SQLITE_ERROR"},
-    {2, "SQLITE_INTERNAL"},
-    {3, "SQLITE_PERM"},
-    {4, "SQLITE_ABORT"},
-    {5, "SQLITE_BUSY"},
-    {6, "SQLITE_LOCKED"},
-    {7, "SQLITE_NOMEM"},
-    {8, "SQLITE_READONLY"},
-    {9, "SQLITE_INTERRUPT"},
-    {10, "SQLITE_IOERR"},
-    {11, "SQLITE_CORRUPT"},
-    {12, "SQLITE_NOTFOUND"},
-    {13, "SQLITE_FULL"},
-    {14, "SQLITE_CANTOPEN"},
-    {15, "SQLITE_PROTOCOL"},
-    {16, "SQLITE_EMPTY"},
-    {17, "SQLITE_SCHEMA"},
-    {18, "SQLITE_TOOBIG"},
-    {19, "SQLITE_CONSTRAINT"},
-    {20, "SQLITE_MISMATCH"},
-    {21, "SQLITE_MISUSE"},
-    {22, "SQLITE_NOLFS"},
-    {23, "SQLITE_AUTH"},
-    {24, "SQLITE_FORMAT"},
-    {25, "SQLITE_RANGE"},
-    {26, "SQLITE_NOTADB"},
-    {27, "SQLITE_NOTICE"},
-    {28, "SQLITE_WARNING"},
-    {100, "SQLITE_ROW"},
+    {0, "SQLITE_OK"},        {1, "SQLITE_ERROR"},       {2, "SQLITE_INTERNAL"},
+    {3, "SQLITE_PERM"},      {4, "SQLITE_ABORT"},       {5, "SQLITE_BUSY"},
+    {6, "SQLITE_LOCKED"},    {7, "SQLITE_NOMEM"},       {8, "SQLITE_READONLY"},
+    {9, "SQLITE_INTERRUPT"}, {10, "SQLITE_IOERR"},      {11, "SQLITE_CORRUPT"},
+    {12, "SQLITE_NOTFOUND"}, {13, "SQLITE_FULL"},       {14, "SQLITE_CANTOPEN"},
+    {15, "SQLITE_PROTOCOL"}, {16, "SQLITE_EMPTY"},      {17, "SQLITE_SCHEMA"},
+    {18, "SQLITE_TOOBIG"},   {19, "SQLITE_CONSTRAINT"}, {20, "SQLITE_MISMATCH"},
+    {21, "SQLITE_MISUSE"},   {22, "SQLITE_NOLFS"},      {23, "SQLITE_AUTH"},
+    {24, "SQLITE_FORMAT"},   {25, "SQLITE_RANGE"},      {26, "SQLITE_NOTADB"},
+    {27, "SQLITE_NOTICE"},   {28, "SQLITE_WARNING"},    {100, "SQLITE_ROW"},
     {101, "SQLITE_DONE"},
 };
 
 const std::map<std::string, std::string> kMemoryDBSettings = {
-    {"synchronous", "OFF"},
-    {"count_changes", "OFF"},
-    {"default_temp_store", "0"},
-    {"auto_vacuum", "FULL"},
-    {"journal_mode", "OFF"},
-    {"cache_size", "0"},
+    {"synchronous", "OFF"},      {"count_changes", "OFF"},
+    {"default_temp_store", "0"}, {"auto_vacuum", "FULL"},
+    {"journal_mode", "OFF"},     {"cache_size", "0"},
     {"page_count", "0"},
 };
+// clang-format on
 
 #define OpComparator(x) \
   { x, QueryPlanner::Opcode(OpReg::P2, INTEGER_TYPE) }
@@ -200,6 +179,9 @@ static inline void openOptimized(sqlite3*& db) {
     settings += "PRAGMA " + setting.first + "=" + setting.second + "; ";
   }
   sqlite3_exec(db, settings.c_str(), nullptr, nullptr, nullptr);
+
+  // Register function extensions.
+  registerMathExtensions(db);
 }
 
 void SQLiteDBInstance::init() {

osquery/sql/sqlite_util.h

@@ -317,4 +317,9 @@ std::string getStringForSQLiteReturnCode(int code);
  * should be a non-const reference to a std::vector<Row>.
  */
 int queryDataCallback(void* argument, int argc, char* argv[], char* column[]);
+
+/**
+ * @brief Register math-related 'custom' functions.
+ */
+void registerMathExtensions(sqlite3* db);
 }