xref: /sqlite-3.40.0/test/fuzz3.test (revision f2fb044b) 
1# 2007 May 10
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# This file implements regression tests for SQLite library.  The focus
12# of this file is checking the libraries response to subtly corrupting
13# the database file by changing the values of pseudo-randomly selected
14# bytes.
15#
16# $Id: fuzz3.test,v 1.1 2008/09/09 18:28:07 danielk1977 Exp $
17
18set testdir [file dirname $argv0]
19source $testdir/tester.tcl
20
21
22expr srand(123)
23
24proc rstring {n} {
25  set str s
26  while {[string length $str] < $n} {
27    append str [expr rand()]
28  }
29  return [string range $str 0 $n]
30}
31
32# Return a randomly generated SQL literal.
33#
34proc rvalue {} {
35  switch -- [expr int(rand()*5)] {
36    0 { # SQL NULL value.
37      return NULL
38    }
39    1 { # Integer value.
40      return [expr int(rand()*1024)]
41    }
42    2 { # Real value.
43      return [expr rand()]
44    }
45    3 { # String value.
46      set n [expr int(rand()*2500)]
47      return "'[rstring $n]'"
48    }
49    4 { # Blob value.
50      set n [expr int(rand()*2500)]
51      return "CAST('[rstring $n]' AS BLOB)"
52    }
53  }
54}
55
56proc db_checksum {} {
57  set    cksum [execsql { SELECT md5sum(a, b, c) FROM t1 }]
58  append cksum [execsql { SELECT md5sum(d, e, f) FROM t2 }]
59  set cksum
60}
61
62# Modify a single byte in the file 'test.db' using tcl IO commands. The
63# argument value, which must be an integer, determines both the offset of
64# the byte that is modified, and the value that it is set to. The lower
65# 8 bits of iMod determine the new byte value. The offset of the byte
66# modified is the value of ($iMod >> 8).
67#
68# The return value is the iMod value required to restore the file
69# to its original state. The command:
70#
71#   modify_database [modify_database $x]
72#
73# leaves the file in the same state as it was in at the start of the
74# command (assuming that the file is at least ($x>>8) bytes in size).
75#
76proc modify_database {iMod} {
77  set blob [binary format c [expr {$iMod&0xFF}]]
78  set offset [expr {$iMod>>8}]
79
80  set fd [open test.db r+]
81  fconfigure $fd -encoding binary -translation binary
82  seek $fd $offset
83  set old_blob [read $fd 1]
84  seek $fd $offset
85  puts -nonewline $fd $blob
86  close $fd
87
88  binary scan $old_blob c iOld
89  return [expr {($offset<<8) + ($iOld&0xFF)}]
90}
91
92proc purge_pcache {} {
93  ifcapable !memorymanage {
94    db close
95    sqlite3 db test.db
96  } else {
97    sqlite3_release_memory 10000000
98  }
99  if {[lindex [pcache_stats] 1] != 0} {
100    error "purge_pcache failed: [pcache_stats]"
101  }
102}
103
104# This block creates a database to work with.
105#
106do_test fuzz3-1 {
107  execsql {
108    BEGIN;
109    CREATE TABLE t1(a, b, c);
110    CREATE TABLE t2(d, e, f);
111    CREATE INDEX i1 ON t1(a, b, c);
112    CREATE INDEX i2 ON t2(d, e, f);
113  }
114  for {set i 0} {$i < 50} {incr i} {
115    execsql "INSERT INTO t1 VALUES([rvalue], [rvalue], [rvalue])"
116    execsql "INSERT INTO t2 VALUES([rvalue], [rvalue], [rvalue])"
117  }
118  execsql COMMIT
119} {}
120
121set ::cksum [db_checksum]
122do_test fuzz3-2 {
123  db_checksum
124} $::cksum
125
126for {set ii 0} {$ii < 10000} {incr ii} {
127  purge_pcache
128
129  # Randomly modify a single byte of the database file somewhere within
130  # the first 100KB of the file.
131  set iNew [expr int(rand()*5*1024*256)]
132  set iOld [modify_database $iNew]
133
134  set iTest 2
135  foreach sql {
136    {SELECT * FROM t1}
137    {SELECT * FROM t2}
138    {SELECT * FROM t1 ORDER BY a}
139    {SELECT * FROM t2 ORDER BY d}
140    {SELECT * FROM t1 WHERE a = (SELECT a FROM t1 WHERE rowid=25)}
141    {SELECT * FROM t2 WHERE d = (SELECT d FROM t2 WHERE rowid=1)}
142    {SELECT * FROM t2 WHERE d = (SELECT d FROM t2 WHERE rowid=50)}
143    {PRAGMA integrity_check}
144  } {
145    do_test fuzz3-$ii.$iNew.[incr iTest] {
146      foreach {rc msg} [catchsql $sql] {}
147      if {$rc == 0
148       || $msg eq "database disk image is malformed"
149       || $msg eq "file is encrypted or is not a database"
150       || [string match "malformed database schema*" $msg]
151      } {
152        set msg ok
153      }
154      set msg
155    } {ok}
156  }
157
158  # Restore the original database file content. Test that the correct
159  # checksum is now returned.
160  #
161  purge_pcache
162  modify_database $iOld
163  do_test fuzz3-$ii.$iNew.[incr iTest] {
164    db_checksum
165  } $::cksum
166}
167
168finish_test
169
170