src/debug.c

#include "redis.h"
#include "sha1.h"   /* SHA1 is used for DEBUG DIGEST */

#include <arpa/inet.h>

/* ================================= Debugging ============================== */

/* Compute the sha1 of string at 's' with 'len' bytes long.
 * The SHA1 is then xored againt the string pointed by digest.
 * Since xor is commutative, this operation is used in order to
 * "add" digests relative to unordered elements.
 *
 * So digest(a,b,c,d) will be the same of digest(b,a,c,d) */
void xorDigest(unsigned char *digest, void *ptr, size_t len) {
    SHA1_CTX ctx;
    unsigned char hash[20], *s = ptr;
    int j;

    SHA1Init(&ctx);
    SHA1Update(&ctx,s,len);
    SHA1Final(hash,&ctx);

    for (j = 0; j < 20; j++)
        digest[j] ^= hash[j];
}

void xorObjectDigest(unsigned char *digest, robj *o) {
    o = getDecodedObject(o);
    xorDigest(digest,o->ptr,sdslen(o->ptr));
    decrRefCount(o);
}

/* This function instead of just computing the SHA1 and xoring it
 * against diget, also perform the digest of "digest" itself and
 * replace the old value with the new one.
 *
 * So the final digest will be:
 *
 * digest = SHA1(digest xor SHA1(data))
 *
 * This function is used every time we want to preserve the order so
 * that digest(a,b,c,d) will be different than digest(b,c,d,a)
 *
 * Also note that mixdigest("foo") followed by mixdigest("bar")
 * will lead to a different digest compared to "fo", "obar".
 */
void mixDigest(unsigned char *digest, void *ptr, size_t len) {
    SHA1_CTX ctx;
    char *s = ptr;

    xorDigest(digest,s,len);
    SHA1Init(&ctx);
    SHA1Update(&ctx,digest,20);
    SHA1Final(digest,&ctx);
}

void mixObjectDigest(unsigned char *digest, robj *o) {
    o = getDecodedObject(o);
    mixDigest(digest,o->ptr,sdslen(o->ptr));
    decrRefCount(o);
}

/* Compute the dataset digest. Since keys, sets elements, hashes elements
 * are not ordered, we use a trick: every aggregate digest is the xor
 * of the digests of their elements. This way the order will not change
 * the result. For list instead we use a feedback entering the output digest
 * as input in order to ensure that a different ordered list will result in
 * a different digest. */
void computeDatasetDigest(unsigned char *final) {
    unsigned char digest[20];
    char buf[128];
    dictIterator *di = NULL;
    dictEntry *de;
    int j;
    uint32_t aux;

    memset(final,0,20); /* Start with a clean result */

    for (j = 0; j < server.dbnum; j++) {
        redisDb *db = server.db+j;

        if (dictSize(db->dict) == 0) continue;
        di = dictGetIterator(db->dict);

        /* hash the DB id, so the same dataset moved in a different
         * DB will lead to a different digest */
        aux = htonl(j);
        mixDigest(final,&aux,sizeof(aux));

        /* Iterate this DB writing every entry */
        while((de = dictNext(di)) != NULL) {
            sds key;
            robj *keyobj, *o;
            time_t expiretime;

            memset(digest,0,20); /* This key-val digest */
            key = dictGetEntryKey(de);
            keyobj = createStringObject(key,sdslen(key));

            mixDigest(digest,key,sdslen(key));

            /* Make sure the key is loaded if VM is active */
            o = dictGetEntryVal(de);

            aux = htonl(o->type);
            mixDigest(digest,&aux,sizeof(aux));
            expiretime = getExpire(db,keyobj);

            /* Save the key and associated value */
            if (o->type == REDIS_STRING) {
                mixObjectDigest(digest,o);
            } else if (o->type == REDIS_LIST) {
                listTypeIterator *li = listTypeInitIterator(o,0,REDIS_TAIL);
                listTypeEntry entry;
                while(listTypeNext(li,&entry)) {
                    robj *eleobj = listTypeGet(&entry);
                    mixObjectDigest(digest,eleobj);
                    decrRefCount(eleobj);
                }
                listTypeReleaseIterator(li);
            } else if (o->type == REDIS_SET) {
                setTypeIterator *si = setTypeInitIterator(o);
                robj *ele;
                while((ele = setTypeNextObject(si)) != NULL) {
                    xorObjectDigest(digest,ele);
                    decrRefCount(ele);
                }
                setTypeReleaseIterator(si);
            } else if (o->type == REDIS_ZSET) {
                unsigned char eledigest[20];

                if (o->encoding == REDIS_ENCODING_ZIPLIST) {
                    unsigned char *zl = o->ptr;
                    unsigned char *eptr, *sptr;
                    unsigned char *vstr;
                    unsigned int vlen;
                    long long vll;
                    double score;

                    eptr = ziplistIndex(zl,0);
                    redisAssert(eptr != NULL);
                    sptr = ziplistNext(zl,eptr);
                    redisAssert(sptr != NULL);

                    while (eptr != NULL) {
                        redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
                        score = zzlGetScore(sptr);

                        memset(eledigest,0,20);
                        if (vstr != NULL) {
                            mixDigest(eledigest,vstr,vlen);
                        } else {
                            ll2string(buf,sizeof(buf),vll);
                            mixDigest(eledigest,buf,strlen(buf));
                        }

                        snprintf(buf,sizeof(buf),"%.17g",score);
                        mixDigest(eledigest,buf,strlen(buf));
                        xorDigest(digest,eledigest,20);
                        zzlNext(zl,&eptr,&sptr);
                    }
                } else if (o->encoding == REDIS_ENCODING_SKIPLIST) {
                    zset *zs = o->ptr;
                    dictIterator *di = dictGetIterator(zs->dict);
                    dictEntry *de;

                    while((de = dictNext(di)) != NULL) {
                        robj *eleobj = dictGetEntryKey(de);
                        double *score = dictGetEntryVal(de);

                        snprintf(buf,sizeof(buf),"%.17g",*score);
                        memset(eledigest,0,20);
                        mixObjectDigest(eledigest,eleobj);
                        mixDigest(eledigest,buf,strlen(buf));
                        xorDigest(digest,eledigest,20);
                    }
                    dictReleaseIterator(di);
                } else {
                    redisPanic("Unknown sorted set encoding");
                }
            } else if (o->type == REDIS_HASH) {
                hashTypeIterator *hi;
                robj *obj;

                hi = hashTypeInitIterator(o);
                while (hashTypeNext(hi) != REDIS_ERR) {
                    unsigned char eledigest[20];

                    memset(eledigest,0,20);
                    obj = hashTypeCurrentObject(hi,REDIS_HASH_KEY);
                    mixObjectDigest(eledigest,obj);
                    decrRefCount(obj);
                    obj = hashTypeCurrentObject(hi,REDIS_HASH_VALUE);
                    mixObjectDigest(eledigest,obj);
                    decrRefCount(obj);
                    xorDigest(digest,eledigest,20);
                }
                hashTypeReleaseIterator(hi);
            } else {
                redisPanic("Unknown object type");
            }
            /* If the key has an expire, add it to the mix */
            if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
            /* We can finally xor the key-val digest to the final digest */
            xorDigest(final,digest,20);
            decrRefCount(keyobj);
        }
        dictReleaseIterator(di);
    }
}

void debugCommand(redisClient *c) {
    if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
        *((char*)-1) = 'x';
    } else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
        if (rdbSave(server.dbfilename) != REDIS_OK) {
            addReply(c,shared.err);
            return;
        }
        emptyDb();
        if (rdbLoad(server.dbfilename) != REDIS_OK) {
            addReply(c,shared.err);
            return;
        }
        redisLog(REDIS_WARNING,"DB reloaded by DEBUG RELOAD");
        addReply(c,shared.ok);
    } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
        emptyDb();
        if (loadAppendOnlyFile(server.appendfilename) != REDIS_OK) {
            addReply(c,shared.err);
            return;
        }
        redisLog(REDIS_WARNING,"Append Only File loaded by DEBUG LOADAOF");
        addReply(c,shared.ok);
    } else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
        dictEntry *de;
        robj *val;
        char *strenc;

        if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
            addReply(c,shared.nokeyerr);
            return;
        }
        val = dictGetEntryVal(de);
        strenc = strEncoding(val->encoding);

        addReplyStatusFormat(c,
            "Value at:%p refcount:%d "
            "encoding:%s serializedlength:%lld "
            "lru:%d lru_seconds_idle:%lu",
            (void*)val, val->refcount,
            strenc, (long long) rdbSavedObjectLen(val),
            val->lru, estimateObjectIdleTime(val));
    } else if (!strcasecmp(c->argv[1]->ptr,"populate") && c->argc == 3) {
        long keys, j;
        robj *key, *val;
        char buf[128];

        if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
            return;
        for (j = 0; j < keys; j++) {
            snprintf(buf,sizeof(buf),"key:%lu",j);
            key = createStringObject(buf,strlen(buf));
            if (lookupKeyRead(c->db,key) != NULL) {
                decrRefCount(key);
                continue;
            }
            snprintf(buf,sizeof(buf),"value:%lu",j);
            val = createStringObject(buf,strlen(buf));
            dbAdd(c->db,key,val);
            decrRefCount(key);
        }
        addReply(c,shared.ok);
    } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
        unsigned char digest[20];
        sds d = sdsempty();
        int j;

        computeDatasetDigest(digest);
        for (j = 0; j < 20; j++)
            d = sdscatprintf(d, "%02x",digest[j]);
        addReplyStatus(c,d);
        sdsfree(d);
    } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
        double dtime = strtod(c->argv[2]->ptr,NULL);
        long long utime = dtime*1000000;

        usleep(utime);
        addReply(c,shared.ok);
    } else {
        addReplyError(c,
            "Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPIN <key>|SWAPOUT <key>|RELOAD]");
    }
}

void _redisAssert(char *estr, char *file, int line) {
    redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
    redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
#ifdef HAVE_BACKTRACE
    redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
    *((char*)-1) = 'x';
#endif
}

void _redisPanic(char *msg, char *file, int line) {
    redisLog(REDIS_WARNING,"------------------------------------------------");
    redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
    redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
#ifdef HAVE_BACKTRACE
    redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
    redisLog(REDIS_WARNING,"------------------------------------------------");
    *((char*)-1) = 'x';
#endif
}
Commit	Line	Data
	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 if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
	285	double dtime = strtod(c->argv[2]->ptr,NULL);
	286	long long utime = dtime*1000000;
	287
	288	usleep(utime);
	289	addReply(c,shared.ok);
	290	} else {
	291	addReplyError(c,
	292	"Syntax error, try DEBUG [SEGFAULT\|OBJECT <key>\|SWAPIN <key>\|SWAPOUT <key>\|RELOAD]");
	293	}
	294	}
	295
	296	void _redisAssert(char estr, char file, int line) {
	297	redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
	298	redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
	299	#ifdef HAVE_BACKTRACE
	300	redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
	301	((char)-1) = 'x';
	302	#endif
	303	}
	304
	305	void _redisPanic(char msg, char file, int line) {
	306	redisLog(REDIS_WARNING,"------------------------------------------------");
	307	redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
	308	redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
	309	#ifdef HAVE_BACKTRACE
	310	redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
	311	redisLog(REDIS_WARNING,"------------------------------------------------");
	312	((char)-1) = 'x';
	313	#endif
	314	}