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Overview
Comment: | Add command-line utilities "offsets.c" and "extract.c" for use in low-level analyzsis of database files. |
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Timelines: | family | ancestors | descendants | both | trunk |
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SHA1: |
dfa22ed4387f9526b74d5265503c7c8e |
User & Date: | drh 2011-08-09 18:14:36.327 |
Context
2011-08-10
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01:52 | Make the openDirectory routine in os_unix.c overrideable so that it can be turned into a harmless no-op for the chromium sandbox. (check-in: 6b236069e1 user: drh tags: trunk) | |
2011-08-09
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18:14 | Add command-line utilities "offsets.c" and "extract.c" for use in low-level analyzsis of database files. (check-in: dfa22ed438 user: drh tags: trunk) | |
2011-08-08
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23:48 | In os_unix.c, do not open the directory containing the database file when the database file is opened. Instead, wait until time to fsync() the directory. And do not report an error if the open fails, since some systems (Ex: AIX and a chromium sandbox) are unable to open and fsync directories. (check-in: 713b1b7dc1 user: drh tags: trunk) | |
Changes
Added tool/extract.c.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | /* ** Extract a range of bytes from a file. ** ** Usage: ** ** extract FILENAME OFFSET AMOUNT ** ** The bytes are written to standard output. */ #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv){ FILE *f; char *zBuf; int ofst; int n; size_t got; if( argc!=4 ){ fprintf(stderr, "Usage: %s FILENAME OFFSET AMOUNT\n", *argv); return 1; } f = fopen(argv[1], "rb"); if( f==0 ){ fprintf(stderr, "cannot open \"%s\"\n", argv[1]); return 1; } ofst = atoi(argv[2]); n = atoi(argv[3]); zBuf = malloc( n ); if( zBuf==0 ){ fprintf(stderr, "out of memory\n"); return 1; } fseek(f, ofst, SEEK_SET); got = fread(zBuf, 1, n, f); fclose(f); if( got<n ){ fprintf(stderr, "got only %d of %d bytes\n", got, n); return 1; }else{ fwrite(zBuf, 1, n, stdout); } return 0; } |
Added tool/offsets.c.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 | /* ** This program searches an SQLite database file for the lengths and ** offsets for all TEXT or BLOB entries for a particular column of a ** particular table. The rowid, size and offset for the column are ** written to standard output. There are three arguments, which are the ** name of the database file, the table, and the column. */ #include "sqlite3.h" #include <stdio.h> #include <stdlib.h> #include <stdarg.h> #include <string.h> typedef unsigned char u8; typedef struct GState GState; #define ArraySize(X) (sizeof(X)/sizeof(X[0])) /* ** Global state information for this program. */ struct GState { char *zErr; /* Error message text */ FILE *f; /* Open database file */ int szPg; /* Page size for the database file */ int iRoot; /* Root page of the table */ int iCol; /* Column number for the column */ int pgno; /* Current page number */ u8 *aPage; /* Current page content */ u8 *aStack[20]; /* Page stack */ int aPgno[20]; /* Page number stack */ int nStack; /* Depth of stack */ int bTrace; /* True for tracing output */ }; /* ** Write an error. */ static void ofstError(GState *p, const char *zFormat, ...){ va_list ap; sqlite3_free(p->zErr); va_start(ap, zFormat); p->zErr = sqlite3_vmprintf(zFormat, ap); va_end(ap); } /* ** Write a trace message */ static void ofstTrace(GState *p, const char *zFormat, ...){ va_list ap; if( p->bTrace ){ va_start(ap, zFormat); vprintf(zFormat, ap); va_end(ap); } } /* ** Find the root page of the table and the column number of the column. */ static void ofstRootAndColumn( GState *p, /* Global state */ const char *zFile, /* Name of the database file */ const char *zTable, /* Name of the table */ const char *zColumn /* Name of the column */ ){ sqlite3 *db = 0; sqlite3_stmt *pStmt = 0; char *zSql = 0; int rc; if( p->zErr ) return; rc = sqlite3_open(zFile, &db); if( rc ){ ofstError(p, "cannot open database file \"%s\"", zFile); goto rootAndColumn_exit; } zSql = sqlite3_mprintf("SELECT rootpage FROM sqlite_master WHERE name=%Q", zTable); rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); if( rc ) ofstError(p, "%s: [%s]", sqlite3_errmsg(db), zSql); sqlite3_free(zSql); if( p->zErr ) goto rootAndColumn_exit; if( sqlite3_step(pStmt)!=SQLITE_ROW ){ ofstError(p, "cannot find table [%s]\n", zTable); sqlite3_finalize(pStmt); goto rootAndColumn_exit; } p->iRoot = sqlite3_column_int(pStmt , 0); sqlite3_finalize(pStmt); p->iCol = -1; zSql = sqlite3_mprintf("PRAGMA table_info(%Q)", zTable); rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); if( rc ) ofstError(p, "%s: [%s}", sqlite3_errmsg(db), zSql); sqlite3_free(zSql); if( p->zErr ) goto rootAndColumn_exit; while( sqlite3_step(pStmt)==SQLITE_ROW ){ const char *zCol = sqlite3_column_text(pStmt, 1); if( strlen(zCol)==strlen(zColumn) && sqlite3_strnicmp(zCol, zColumn, strlen(zCol))==0 ){ p->iCol = sqlite3_column_int(pStmt, 0); break; } } sqlite3_finalize(pStmt); if( p->iCol<0 ){ ofstError(p, "no such column: %s.%s", zTable, zColumn); goto rootAndColumn_exit; } zSql = sqlite3_mprintf("PRAGMA page_size"); rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); if( rc ) ofstError(p, "%s: [%s]", sqlite3_errmsg(db), zSql); sqlite3_free(zSql); if( p->zErr ) goto rootAndColumn_exit; if( sqlite3_step(pStmt)!=SQLITE_ROW ){ ofstError(p, "cannot find page size"); }else{ p->szPg = sqlite3_column_int(pStmt, 0); } sqlite3_finalize(pStmt); rootAndColumn_exit: sqlite3_close(db); return; } /* ** Pop a page from the stack */ static void ofstPopPage(GState *p){ if( p->nStack<=0 ) return; p->nStack--; sqlite3_free(p->aStack[p->nStack]); p->pgno = p->aPgno[p->nStack-1]; p->aPage = p->aStack[p->nStack-1]; } /* ** Push a new page onto the stack. */ static void ofstPushPage(GState *p, int pgno){ u8 *pPage; size_t got; if( p->zErr ) return; if( p->nStack >= ArraySize(p->aStack) ){ ofstError(p, "page stack overflow"); return; } p->aPgno[p->nStack] = pgno; p->aStack[p->nStack] = pPage = sqlite3_malloc( p->szPg ); if( pPage==0 ){ fprintf(stderr, "out of memory\n"); exit(1); } p->nStack++; p->aPage = pPage; p->pgno = pgno; fseek(p->f, (pgno-1)*p->szPg, SEEK_SET); got = fread(pPage, 1, p->szPg, p->f); if( got!=p->szPg ){ ofstError(p, "unable to read page %d", pgno); ofstPopPage(p); } } /* Read a two-byte integer at the given offset into the current page */ static int ofst2byte(GState *p, int ofst){ int x = p->aPage[ofst]; return (x<<8) + p->aPage[ofst+1]; } /* Read a four-byte integer at the given offset into the current page */ static int ofst4byte(GState *p, int ofst){ int x = p->aPage[ofst]; x = (x<<8) + p->aPage[ofst+1]; x = (x<<8) + p->aPage[ofst+2]; x = (x<<8) + p->aPage[ofst+3]; return x; } /* Read a variable-length integer. Update the offset */ static sqlite3_int64 ofstVarint(GState *p, int *pOfst){ sqlite3_int64 x = 0; u8 *a = &p->aPage[*pOfst]; int n = 0; while( n<8 && (a[0] & 0x80)!=0 ){ x = (x<<7) + (a[0] & 0x7f); n++; a++; } if( n==8 ){ x = (x<<8) + a[0]; }else{ x = (x<<7) + a[0]; } *pOfst += (n+1); return x; } /* Return the absolute offset into a file for the given offset ** into the current page */ static int ofstInFile(GState *p, int ofst){ return p->szPg*(p->pgno-1) + ofst; } /* Return the size (in bytes) of the data corresponding to the ** given serial code */ static int ofstSerialSize(int scode){ if( scode<5 ) return scode; if( scode==5 ) return 6; if( scode<8 ) return 8; if( scode<12 ) return 0; return (scode-12)/2; } /* Forward reference */ static void ofstWalkPage(GState*, int); /* Walk an interior btree page */ static void ofstWalkInteriorPage(GState *p){ int nCell; int i; int ofst; int iChild; nCell = ofst2byte(p, 3); for(i=0; i<nCell; i++){ ofst = ofst2byte(p, 12+i*2); iChild = ofst4byte(p, ofst); ofstWalkPage(p, iChild); if( p->zErr ) return; } ofstWalkPage(p, ofst4byte(p, 8)); } /* Walk a leaf btree page */ static void ofstWalkLeafPage(GState *p){ int nCell; int i; int ofst; int nPayload; sqlite3_int64 rowid; int nHdr; int j; int scode; int sz; int dataOfst; char zMsg[200]; nCell = ofst2byte(p, 3); for(i=0; i<nCell; i++){ ofst = ofst2byte(p, 8+i*2); nPayload = ofstVarint(p, &ofst); rowid = ofstVarint(p, &ofst); if( nPayload > p->szPg-35 ){ sqlite3_snprintf(sizeof(zMsg), zMsg, "# overflow rowid %lld", rowid); printf("%s\n", zMsg); continue; } dataOfst = ofst; nHdr = ofstVarint(p, &ofst); dataOfst += nHdr; for(j=0; j<p->iCol; j++){ scode = ofstVarint(p, &ofst); dataOfst += ofstSerialSize(scode); } scode = ofstVarint(p, &ofst); sz = ofstSerialSize(scode); sqlite3_snprintf(sizeof(zMsg), zMsg, "rowid %12lld size %5d offset %8d", rowid, sz, ofstInFile(p, dataOfst)); printf("%s\n", zMsg); } } /* ** Output results from a single page. */ static void ofstWalkPage(GState *p, int pgno){ if( p->zErr ) return; ofstPushPage(p, pgno); if( p->zErr ) return; if( p->aPage[0]==5 ){ ofstWalkInteriorPage(p); }else if( p->aPage[0]==13 ){ ofstWalkLeafPage(p); }else{ ofstError(p, "page %d has a faulty type byte: %d", pgno, p->aPage[0]); } ofstPopPage(p); } int main(int argc, char **argv){ GState g; memset(&g, 0, sizeof(g)); if( argc>2 && strcmp(argv[1],"--trace")==0 ){ g.bTrace = 1; argc--; argv++; } if( argc!=4 ){ fprintf(stderr, "Usage: %s DATABASE TABLE COLUMN\n", *argv); exit(1); } ofstRootAndColumn(&g, argv[1], argv[2], argv[3]); if( g.zErr ){ fprintf(stderr, "%s\n", g.zErr); exit(1); } ofstTrace(&g, "# szPg = %d\n", g.szPg); ofstTrace(&g, "# iRoot = %d\n", g.iRoot); ofstTrace(&g, "# iCol = %d\n", g.iCol); g.f = fopen(argv[1], "rb"); if( g.f==0 ){ fprintf(stderr, "cannot open \"%s\"\n", argv[1]); exit(1); } ofstWalkPage(&g, g.iRoot); if( g.zErr ){ fprintf(stderr, "%s\n", g.zErr); exit(1); } return 0; } |