1 #include "redis.h" 2 #include "sha1.h" /* SHA1 is used for DEBUG DIGEST */ 3 4 #include <arpa/inet.h> 5 6 /* ================================= Debugging ============================== */ 7 8 /* Compute the sha1 of string at 's' with 'len' bytes long. 9 * The SHA1 is then xored againt the string pointed by digest. 10 * Since xor is commutative, this operation is used in order to 11 * "add" digests relative to unordered elements. 12 * 13 * So digest(a,b,c,d) will be the same of digest(b,a,c,d) */ 14 void xorDigest(unsigned char *digest, void *ptr, size_t len) { 15 SHA1_CTX ctx; 16 unsigned char hash[20], *s = ptr; 17 int j; 18 19 SHA1Init(&ctx); 20 SHA1Update(&ctx,s,len); 21 SHA1Final(hash,&ctx); 22 23 for (j = 0; j < 20; j++) 24 digest[j] ^= hash[j]; 25 } 26 27 void xorObjectDigest(unsigned char *digest, robj *o) { 28 o = getDecodedObject(o); 29 xorDigest(digest,o->ptr,sdslen(o->ptr)); 30 decrRefCount(o); 31 } 32 33 /* This function instead of just computing the SHA1 and xoring it 34 * against diget, also perform the digest of "digest" itself and 35 * replace the old value with the new one. 36 * 37 * So the final digest will be: 38 * 39 * digest = SHA1(digest xor SHA1(data)) 40 * 41 * This function is used every time we want to preserve the order so 42 * that digest(a,b,c,d) will be different than digest(b,c,d,a) 43 * 44 * Also note that mixdigest("foo") followed by mixdigest("bar") 45 * will lead to a different digest compared to "fo", "obar". 46 */ 47 void mixDigest(unsigned char *digest, void *ptr, size_t len) { 48 SHA1_CTX ctx; 49 char *s = ptr; 50 51 xorDigest(digest,s,len); 52 SHA1Init(&ctx); 53 SHA1Update(&ctx,digest,20); 54 SHA1Final(digest,&ctx); 55 } 56 57 void mixObjectDigest(unsigned char *digest, robj *o) { 58 o = getDecodedObject(o); 59 mixDigest(digest,o->ptr,sdslen(o->ptr)); 60 decrRefCount(o); 61 } 62 63 /* Compute the dataset digest. Since keys, sets elements, hashes elements 64 * are not ordered, we use a trick: every aggregate digest is the xor 65 * of the digests of their elements. This way the order will not change 66 * the result. For list instead we use a feedback entering the output digest 67 * as input in order to ensure that a different ordered list will result in 68 * a different digest. */ 69 void computeDatasetDigest(unsigned char *final) { 70 unsigned char digest[20]; 71 char buf[128]; 72 dictIterator *di = NULL; 73 dictEntry *de; 74 int j; 75 uint32_t aux; 76 77 memset(final,0,20); /* Start with a clean result */ 78 79 for (j = 0; j < server.dbnum; j++) { 80 redisDb *db = server.db+j; 81 82 if (dictSize(db->dict) == 0) continue; 83 di = dictGetIterator(db->dict); 84 85 /* hash the DB id, so the same dataset moved in a different 86 * DB will lead to a different digest */ 87 aux = htonl(j); 88 mixDigest(final,&aux,sizeof(aux)); 89 90 /* Iterate this DB writing every entry */ 91 while((de = dictNext(di)) != NULL) { 92 sds key; 93 robj *keyobj, *o; 94 time_t expiretime; 95 96 memset(digest,0,20); /* This key-val digest */ 97 key = dictGetEntryKey(de); 98 keyobj = createStringObject(key,sdslen(key)); 99 100 mixDigest(digest,key,sdslen(key)); 101 102 /* Make sure the key is loaded if VM is active */ 103 o = dictGetEntryVal(de); 104 105 aux = htonl(o->type); 106 mixDigest(digest,&aux,sizeof(aux)); 107 expiretime = getExpire(db,keyobj); 108 109 /* Save the key and associated value */ 110 if (o->type == REDIS_STRING) { 111 mixObjectDigest(digest,o); 112 } else if (o->type == REDIS_LIST) { 113 listTypeIterator *li = listTypeInitIterator(o,0,REDIS_TAIL); 114 listTypeEntry entry; 115 while(listTypeNext(li,&entry)) { 116 robj *eleobj = listTypeGet(&entry); 117 mixObjectDigest(digest,eleobj); 118 decrRefCount(eleobj); 119 } 120 listTypeReleaseIterator(li); 121 } else if (o->type == REDIS_SET) { 122 setTypeIterator *si = setTypeInitIterator(o); 123 robj *ele; 124 while((ele = setTypeNextObject(si)) != NULL) { 125 xorObjectDigest(digest,ele); 126 decrRefCount(ele); 127 } 128 setTypeReleaseIterator(si); 129 } else if (o->type == REDIS_ZSET) { 130 unsigned char eledigest[20]; 131 132 if (o->encoding == REDIS_ENCODING_ZIPLIST) { 133 unsigned char *zl = o->ptr; 134 unsigned char *eptr, *sptr; 135 unsigned char *vstr; 136 unsigned int vlen; 137 long long vll; 138 double score; 139 140 eptr = ziplistIndex(zl,0); 141 redisAssert(eptr != NULL); 142 sptr = ziplistNext(zl,eptr); 143 redisAssert(sptr != NULL); 144 145 while (eptr != NULL) { 146 redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll)); 147 score = zzlGetScore(sptr); 148 149 memset(eledigest,0,20); 150 if (vstr != NULL) { 151 mixDigest(eledigest,vstr,vlen); 152 } else { 153 ll2string(buf,sizeof(buf),vll); 154 mixDigest(eledigest,buf,strlen(buf)); 155 } 156 157 snprintf(buf,sizeof(buf),"%.17g",score); 158 mixDigest(eledigest,buf,strlen(buf)); 159 xorDigest(digest,eledigest,20); 160 zzlNext(zl,&eptr,&sptr); 161 } 162 } else if (o->encoding == REDIS_ENCODING_SKIPLIST) { 163 zset *zs = o->ptr; 164 dictIterator *di = dictGetIterator(zs->dict); 165 dictEntry *de; 166 167 while((de = dictNext(di)) != NULL) { 168 robj *eleobj = dictGetEntryKey(de); 169 double *score = dictGetEntryVal(de); 170 171 snprintf(buf,sizeof(buf),"%.17g",*score); 172 memset(eledigest,0,20); 173 mixObjectDigest(eledigest,eleobj); 174 mixDigest(eledigest,buf,strlen(buf)); 175 xorDigest(digest,eledigest,20); 176 } 177 dictReleaseIterator(di); 178 } else { 179 redisPanic("Unknown sorted set encoding"); 180 } 181 } else if (o->type == REDIS_HASH) { 182 hashTypeIterator *hi; 183 robj *obj; 184 185 hi = hashTypeInitIterator(o); 186 while (hashTypeNext(hi) != REDIS_ERR) { 187 unsigned char eledigest[20]; 188 189 memset(eledigest,0,20); 190 obj = hashTypeCurrentObject(hi,REDIS_HASH_KEY); 191 mixObjectDigest(eledigest,obj); 192 decrRefCount(obj); 193 obj = hashTypeCurrentObject(hi,REDIS_HASH_VALUE); 194 mixObjectDigest(eledigest,obj); 195 decrRefCount(obj); 196 xorDigest(digest,eledigest,20); 197 } 198 hashTypeReleaseIterator(hi); 199 } else { 200 redisPanic("Unknown object type"); 201 } 202 /* If the key has an expire, add it to the mix */ 203 if (expiretime != -1) xorDigest(digest,"!!expire!!",10); 204 /* We can finally xor the key-val digest to the final digest */ 205 xorDigest(final,digest,20); 206 decrRefCount(keyobj); 207 } 208 dictReleaseIterator(di); 209 } 210 } 211 212 void debugCommand(redisClient *c) { 213 if (!strcasecmp(c->argv[1]->ptr,"segfault")) { 214 *((char*)-1) = 'x'; 215 } else if (!strcasecmp(c->argv[1]->ptr,"reload")) { 216 if (rdbSave(server.dbfilename) != REDIS_OK) { 217 addReply(c,shared.err); 218 return; 219 } 220 emptyDb(); 221 if (rdbLoad(server.dbfilename) != REDIS_OK) { 222 addReply(c,shared.err); 223 return; 224 } 225 redisLog(REDIS_WARNING,"DB reloaded by DEBUG RELOAD"); 226 addReply(c,shared.ok); 227 } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) { 228 emptyDb(); 229 if (loadAppendOnlyFile(server.appendfilename) != REDIS_OK) { 230 addReply(c,shared.err); 231 return; 232 } 233 redisLog(REDIS_WARNING,"Append Only File loaded by DEBUG LOADAOF"); 234 addReply(c,shared.ok); 235 } else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) { 236 dictEntry *de; 237 robj *val; 238 char *strenc; 239 240 if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) { 241 addReply(c,shared.nokeyerr); 242 return; 243 } 244 val = dictGetEntryVal(de); 245 strenc = strEncoding(val->encoding); 246 247 addReplyStatusFormat(c, 248 "Value at:%p refcount:%d " 249 "encoding:%s serializedlength:%lld " 250 "lru:%d lru_seconds_idle:%lu", 251 (void*)val, val->refcount, 252 strenc, (long long) rdbSavedObjectLen(val), 253 val->lru, estimateObjectIdleTime(val)); 254 } else if (!strcasecmp(c->argv[1]->ptr,"populate") && c->argc == 3) { 255 long keys, j; 256 robj *key, *val; 257 char buf[128]; 258 259 if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK) 260 return; 261 for (j = 0; j < keys; j++) { 262 snprintf(buf,sizeof(buf),"key:%lu",j); 263 key = createStringObject(buf,strlen(buf)); 264 if (lookupKeyRead(c->db,key) != NULL) { 265 decrRefCount(key); 266 continue; 267 } 268 snprintf(buf,sizeof(buf),"value:%lu",j); 269 val = createStringObject(buf,strlen(buf)); 270 dbAdd(c->db,key,val); 271 decrRefCount(key); 272 } 273 addReply(c,shared.ok); 274 } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) { 275 unsigned char digest[20]; 276 sds d = sdsempty(); 277 int j; 278 279 computeDatasetDigest(digest); 280 for (j = 0; j < 20; j++) 281 d = sdscatprintf(d, "%02x",digest[j]); 282 addReplyStatus(c,d); 283 sdsfree(d); 284 } else { 285 addReplyError(c, 286 "Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPIN <key>|SWAPOUT <key>|RELOAD]"); 287 } 288 } 289 290 void _redisAssert(char *estr, char *file, int line) { 291 redisLog(REDIS_WARNING,"=== ASSERTION FAILED ==="); 292 redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr); 293 #ifdef HAVE_BACKTRACE 294 redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)"); 295 *((char*)-1) = 'x'; 296 #endif 297 } 298 299 void _redisPanic(char *msg, char *file, int line) { 300 redisLog(REDIS_WARNING,"------------------------------------------------"); 301 redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue"); 302 redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line); 303 #ifdef HAVE_BACKTRACE 304 redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)"); 305 redisLog(REDIS_WARNING,"------------------------------------------------"); 306 *((char*)-1) = 'x'; 307 #endif 308 } 309