test/ossfuzz.c

   1 /*
   2 ** This module interfaces SQLite to the Google OSS-Fuzz, fuzzer as a service.
   3 ** (https://github.com/google/oss-fuzz)
   4 */
   5 #include <stddef.h>
   6 #if !defined(_MSC_VER)
   7 # include <stdint.h>
   8 #endif
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include "sqlite3.h"
  12
  13 #if defined(_MSC_VER)
  14 typedef unsigned char uint8_t;
  15 #endif
  16
  17 /* Global debugging settings.  OSS-Fuzz will have all debugging turned
  18 ** off.  But if LLVMFuzzerTestOneInput() is called interactively from
  19 ** the ossshell utility program, then these flags might be set.
  20 */
  21 static unsigned mDebug = 0;
  22 #define FUZZ_SQL_TRACE       0x0001   /* Set an sqlite3_trace() callback */
  23 #define FUZZ_SHOW_MAX_DELAY  0x0002   /* Show maximum progress callback delay */
  24 #define FUZZ_SHOW_ERRORS     0x0004   /* Print error messages from SQLite */
  25
  26 /* The ossshell utility program invokes this interface to see the
  27 ** debugging flags.  Unused by OSS-Fuzz.
  28 */
  29 void ossfuzz_set_debug_flags(unsigned x){
  30   mDebug = x;
  31 }
  32
  33 /* Return the current real-world time in milliseconds since the
  34 ** Julian epoch (-4714-11-24).
  35 */
  36 static sqlite3_int64 timeOfDay(void){
  37   static sqlite3_vfs *clockVfs = 0;
  38   sqlite3_int64 t;
  39   if( clockVfs==0 ) clockVfs = sqlite3_vfs_find(0);
  40   if( clockVfs->iVersion>=2 && clockVfs->xCurrentTimeInt64!=0 ){
  41     clockVfs->xCurrentTimeInt64(clockVfs, &t);
  42   }else{
  43     double r;
  44     clockVfs->xCurrentTime(clockVfs, &r);
  45     t = (sqlite3_int64)(r*86400000.0);
  46   }
  47   return t;
  48 }
  49
  50 /* An instance of the following object is passed by pointer as the
  51 ** client data to various callbacks.
  52 */
  53 typedef struct FuzzCtx {
  54   sqlite3 *db;               /* The database connection */
  55   sqlite3_int64 iCutoffTime; /* Stop processing at this time. */
  56   sqlite3_int64 iLastCb;     /* Time recorded for previous progress callback */
  57   sqlite3_int64 mxInterval;  /* Longest interval between two progress calls */
  58   unsigned nCb;              /* Number of progress callbacks */
  59 } FuzzCtx;
  60
  61 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  62 /*
  63 ** Progress handler callback.
  64 **
  65 ** The argument is the cutoff-time after which all processing should
  66 ** stop.  So return non-zero if the cut-off time is exceeded.
  67 */
  68 static int progress_handler(void *pClientData) {
  69   FuzzCtx *p = (FuzzCtx*)pClientData;
  70   sqlite3_int64 iNow = timeOfDay();
  71   int rc = iNow>=p->iCutoffTime;
  72   sqlite3_int64 iDiff = iNow - p->iLastCb;
  73   if( iDiff > p->mxInterval ) p->mxInterval = iDiff;
  74   p->nCb++;
  75   return rc;
  76 }
  77 #endif
  78
  79 /*
  80 ** Disallow debugging pragmas such as "PRAGMA vdbe_debug" and
  81 ** "PRAGMA parser_trace" since they can dramatically increase the
  82 ** amount of output without actually testing anything useful.
  83 */
  84 static int block_debug_pragmas(
  85   void *Notused,
  86   int eCode,
  87   const char *zArg1,
  88   const char *zArg2,
  89   const char *zArg3,
  90   const char *zArg4
  91 ){
  92   if( eCode==SQLITE_PRAGMA
  93    && (sqlite3_strnicmp("vdbe_", zArg1, 5)==0
  94         || sqlite3_stricmp("parser_trace", zArg1)==0)
  95   ){
  96     return SQLITE_DENY;
  97   }
  98   return SQLITE_OK;
  99 }
 100
 101 /*
 102 ** Callback for sqlite3_exec().
 103 */
 104 static int exec_handler(void *pCnt, int argc, char **argv, char **namev){
 105   int i;
 106   if( argv ){
 107     for(i=0; i<argc; i++) sqlite3_free(sqlite3_mprintf("%s", argv[i]));
 108   }
 109   return ((*(int*)pCnt)--)<=0;
 110 }
 111
 112 /*
 113 ** Main entry point.  The fuzzer invokes this function with each
 114 ** fuzzed input.
 115 */
 116 int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
 117   int execCnt = 0;         /* Abort row callback when count reaches zero */
 118   char *zErrMsg = 0;       /* Error message returned by sqlite_exec() */
 119   uint8_t uSelector;       /* First byte of input data[] */
 120   int rc;                  /* Return code from various interfaces */
 121   char *zSql;              /* Zero-terminated copy of data[] */
 122   FuzzCtx cx;              /* Fuzzing context */
 123
 124   memset(&cx, 0, sizeof(cx));
 125   if( size<3 ) return 0;   /* Early out if unsufficient data */
 126
 127   /* Extract the selector byte from the beginning of the input.  But only
 128   ** do this if the second byte is a \n.  If the second byte is not \n,
 129   ** then use a default selector */
 130   if( data[1]=='\n' ){
 131     uSelector = data[0];  data += 2; size -= 2;
 132   }else{
 133     uSelector = 0xfd;
 134   }
 135
 136   /* Open the database connection.  Only use an in-memory database. */
 137   rc = sqlite3_open_v2("fuzz.db", &cx.db,
 138            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY, 0);
 139   if( rc ) return 0;
 140
 141 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
 142   /* Invoke the progress handler frequently to check to see if we
 143   ** are taking too long.  The progress handler will return true
 144   ** (which will block further processing) if more than 10 seconds have
 145   ** elapsed since the start of the test.
 146   */
 147   cx.iLastCb = timeOfDay();
 148   cx.iCutoffTime = cx.iLastCb + 10000;  /* Now + 10 seconds */
 149   sqlite3_progress_handler(cx.db, 10, progress_handler, (void*)&cx);
 150 #endif
 151
 152   /* Set a limit on the maximum size of a prepared statement */
 153   sqlite3_limit(cx.db, SQLITE_LIMIT_VDBE_OP, 25000);
 154
 155   /* Bit 1 of the selector enables foreign key constraints */
 156   sqlite3_db_config(cx.db, SQLITE_DBCONFIG_ENABLE_FKEY, uSelector&1, &rc);
 157   uSelector >>= 1;
 158
 159   /* Do not allow debugging pragma statements that might cause excess output */
 160   sqlite3_set_authorizer(cx.db, block_debug_pragmas, 0);
 161
 162   /* Remaining bits of the selector determine a limit on the number of
 163   ** output rows */
 164   execCnt = uSelector + 1;
 165
 166   /* Run the SQL.  The sqlite_exec() interface expects a zero-terminated
 167   ** string, so make a copy. */
 168   zSql = sqlite3_mprintf("%.*s", (int)size, data);
 169 #ifndef SQLITE_OMIT_COMPLETE
 170   sqlite3_complete(zSql);
 171 #endif
 172   sqlite3_exec(cx.db, zSql, exec_handler, (void*)&execCnt, &zErrMsg);
 173
 174   /* Show any errors */
 175   if( (mDebug & FUZZ_SHOW_ERRORS)!=0 && zErrMsg ){
 176     printf("Error: %s\n", zErrMsg);
 177   }
 178
 179   /* Cleanup and return */
 180   sqlite3_free(zErrMsg);
 181   sqlite3_free(zSql);
 182   sqlite3_exec(cx.db, "PRAGMA temp_store_directory=''", 0, 0, 0);
 183   sqlite3_close(cx.db);
 184
 185   if( mDebug & FUZZ_SHOW_MAX_DELAY ){
 186     printf("Progress callback count....... %d\n", cx.nCb);
 187     printf("Max time between callbacks.... %d ms\n", (int)cx.mxInterval);
 188   }
 189   return 0;
 190 }