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 = lookupKeyRead(db,keyobj);

            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) {
                dict *set = o->ptr;
                dictIterator *di = dictGetIterator(set);
                dictEntry *de;

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

                    xorObjectDigest(digest,eleobj);
                }
                dictReleaseIterator(di);
            } else if (o->type == REDIS_ZSET) {
                zset *zs = o->ptr;
                dictIterator *di = dictGetIterator(zs->dict);
                dictEntry *de;

                while((de = dictNext(di)) != NULL) {
                    robj *eleobj = dictGetEntryKey(de);
                    double *score = dictGetEntryVal(de);
                    unsigned char eledigest[20];

                    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 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 = hashTypeCurrent(hi,REDIS_HASH_KEY);
                    mixObjectDigest(eledigest,obj);
                    decrRefCount(obj);
                    obj = hashTypeCurrent(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 = dictFind(c->db->dict,c->argv[2]->ptr);
        robj *val;

        if (!de) {
            addReply(c,shared.nokeyerr);
            return;
        }
        val = dictGetEntryVal(de);
        if (!server.vm_enabled || (val->storage == REDIS_VM_MEMORY ||
                                   val->storage == REDIS_VM_SWAPPING)) {
            char *strenc;

            strenc = strEncoding(val->encoding);
            addReplySds(c,sdscatprintf(sdsempty(),
                "+Value at:%p refcount:%d "
                "encoding:%s serializedlength:%lld\r\n",
                (void*)val, val->refcount,
                strenc, (long long) rdbSavedObjectLen(val,NULL)));
        } else {
            vmpointer *vp = (vmpointer*) val;
            addReplySds(c,sdscatprintf(sdsempty(),
                "+Value swapped at: page %llu "
                "using %llu pages\r\n",
                (unsigned long long) vp->page,
                (unsigned long long) vp->usedpages));
        }
    } else if (!strcasecmp(c->argv[1]->ptr,"swapin") && c->argc == 3) {
        lookupKeyRead(c->db,c->argv[2]);
        addReply(c,shared.ok);
    } else if (!strcasecmp(c->argv[1]->ptr,"swapout") && c->argc == 3) {
        dictEntry *de = dictFind(c->db->dict,c->argv[2]->ptr);
        robj *val;
        vmpointer *vp;

        if (!server.vm_enabled) {
            addReplySds(c,sdsnew("-ERR Virtual Memory is disabled\r\n"));
            return;
        }
        if (!de) {
            addReply(c,shared.nokeyerr);
            return;
        }
        val = dictGetEntryVal(de);
        /* Swap it */
        if (val->storage != REDIS_VM_MEMORY) {
            addReplySds(c,sdsnew("-ERR This key is not in memory\r\n"));
        } else if (val->refcount != 1) {
            addReplySds(c,sdsnew("-ERR Object is shared\r\n"));
        } else if ((vp = vmSwapObjectBlocking(val)) != NULL) {
            dictGetEntryVal(de) = vp;
            addReply(c,shared.ok);
        } else {
            addReply(c,shared.err);
        }
    } 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 = sdsnew("+");
        int j;

        computeDatasetDigest(digest);
        for (j = 0; j < 20; j++)
            d = sdscatprintf(d, "%02x",digest[j]);

        d = sdscatlen(d,"\r\n",2);
        addReplySds(c,d);
    } else {
        addReplySds(c,sdsnew(
            "-ERR Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPIN <key>|SWAPOUT <key>|RELOAD]\r\n"));
    }
}

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,"!!! 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)");
    *((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 = lookupKeyRead(db,keyobj);
	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	dict *set = o->ptr;
	123	dictIterator *di = dictGetIterator(set);
	124	dictEntry *de;
	125
	126	while((de = dictNext(di)) != NULL) {
	127	robj *eleobj = dictGetEntryKey(de);
	128
	129	xorObjectDigest(digest,eleobj);
	130	}
	131	dictReleaseIterator(di);
	132	} else if (o->type == REDIS_ZSET) {
	133	zset *zs = o->ptr;
	134	dictIterator *di = dictGetIterator(zs->dict);
	135	dictEntry *de;
	136
	137	while((de = dictNext(di)) != NULL) {
	138	robj *eleobj = dictGetEntryKey(de);
	139	double *score = dictGetEntryVal(de);
	140	unsigned char eledigest[20];
	141
	142	snprintf(buf,sizeof(buf),"%.17g",*score);
	143	memset(eledigest,0,20);
	144	mixObjectDigest(eledigest,eleobj);
	145	mixDigest(eledigest,buf,strlen(buf));
	146	xorDigest(digest,eledigest,20);
	147	}
	148	dictReleaseIterator(di);
	149	} else if (o->type == REDIS_HASH) {
	150	hashTypeIterator *hi;
	151	robj *obj;
	152
	153	hi = hashTypeInitIterator(o);
	154	while (hashTypeNext(hi) != REDIS_ERR) {
	155	unsigned char eledigest[20];
	156
	157	memset(eledigest,0,20);
	158	obj = hashTypeCurrent(hi,REDIS_HASH_KEY);
	159	mixObjectDigest(eledigest,obj);
	160	decrRefCount(obj);
	161	obj = hashTypeCurrent(hi,REDIS_HASH_VALUE);
	162	mixObjectDigest(eledigest,obj);
	163	decrRefCount(obj);
	164	xorDigest(digest,eledigest,20);
	165	}
	166	hashTypeReleaseIterator(hi);
	167	} else {
	168	redisPanic("Unknown object type");
	169	}
	170	/* If the key has an expire, add it to the mix */
	171	if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
	172	/* We can finally xor the key-val digest to the final digest */
	173	xorDigest(final,digest,20);
	174	decrRefCount(keyobj);
	175	}
	176	dictReleaseIterator(di);
	177	}
	178	}
	179
	180	void debugCommand(redisClient *c) {
	181	if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
	182	((char)-1) = 'x';
	183	} else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
	184	if (rdbSave(server.dbfilename) != REDIS_OK) {
	185	addReply(c,shared.err);
	186	return;
	187	}
	188	emptyDb();
	189	if (rdbLoad(server.dbfilename) != REDIS_OK) {
	190	addReply(c,shared.err);
	191	return;
	192	}
	193	redisLog(REDIS_WARNING,"DB reloaded by DEBUG RELOAD");
	194	addReply(c,shared.ok);
	195	} else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
	196	emptyDb();
	197	if (loadAppendOnlyFile(server.appendfilename) != REDIS_OK) {
	198	addReply(c,shared.err);
	199	return;
	200	}
	201	redisLog(REDIS_WARNING,"Append Only File loaded by DEBUG LOADAOF");
	202	addReply(c,shared.ok);
	203	} else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
	204	dictEntry *de = dictFind(c->db->dict,c->argv[2]->ptr);
	205	robj *val;
	206
	207	if (!de) {
	208	addReply(c,shared.nokeyerr);
	209	return;
	210	}
	211	val = dictGetEntryVal(de);
	212	if (!server.vm_enabled \|\| (val->storage == REDIS_VM_MEMORY \|\|
	213	val->storage == REDIS_VM_SWAPPING)) {
	214	char *strenc;
	215
	216	strenc = strEncoding(val->encoding);
	217	addReplySds(c,sdscatprintf(sdsempty(),
	218	"+Value at:%p refcount:%d "
	219	"encoding:%s serializedlength:%lld\r\n",
	220	(void*)val, val->refcount,
	221	strenc, (long long) rdbSavedObjectLen(val,NULL)));
	222	} else {
	223	vmpointer vp = (vmpointer) val;
	224	addReplySds(c,sdscatprintf(sdsempty(),
	225	"+Value swapped at: page %llu "
	226	"using %llu pages\r\n",
	227	(unsigned long long) vp->page,
	228	(unsigned long long) vp->usedpages));
	229	}
	230	} else if (!strcasecmp(c->argv[1]->ptr,"swapin") && c->argc == 3) {
	231	lookupKeyRead(c->db,c->argv[2]);
	232	addReply(c,shared.ok);
	233	} else if (!strcasecmp(c->argv[1]->ptr,"swapout") && c->argc == 3) {
	234	dictEntry *de = dictFind(c->db->dict,c->argv[2]->ptr);
	235	robj *val;
	236	vmpointer *vp;
	237
	238	if (!server.vm_enabled) {
	239	addReplySds(c,sdsnew("-ERR Virtual Memory is disabled\r\n"));
	240	return;
	241	}
	242	if (!de) {
	243	addReply(c,shared.nokeyerr);
	244	return;
	245	}
	246	val = dictGetEntryVal(de);
	247	/* Swap it */
	248	if (val->storage != REDIS_VM_MEMORY) {
	249	addReplySds(c,sdsnew("-ERR This key is not in memory\r\n"));
	250	} else if (val->refcount != 1) {
	251	addReplySds(c,sdsnew("-ERR Object is shared\r\n"));
	252	} else if ((vp = vmSwapObjectBlocking(val)) != NULL) {
	253	dictGetEntryVal(de) = vp;
	254	addReply(c,shared.ok);
	255	} else {
	256	addReply(c,shared.err);
	257	}
	258	} else if (!strcasecmp(c->argv[1]->ptr,"populate") && c->argc == 3) {
	259	long keys, j;
	260	robj key, val;
	261	char buf[128];
	262
	263	if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
	264	return;
	265	for (j = 0; j < keys; j++) {
	266	snprintf(buf,sizeof(buf),"key:%lu",j);
	267	key = createStringObject(buf,strlen(buf));
	268	if (lookupKeyRead(c->db,key) != NULL) {
	269	decrRefCount(key);
	270	continue;
	271	}
	272	snprintf(buf,sizeof(buf),"value:%lu",j);
	273	val = createStringObject(buf,strlen(buf));
	274	dbAdd(c->db,key,val);
	275	decrRefCount(key);
	276	}
	277	addReply(c,shared.ok);
	278	} else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
	279	unsigned char digest[20];
	280	sds d = sdsnew("+");
	281	int j;
	282
	283	computeDatasetDigest(digest);
	284	for (j = 0; j < 20; j++)
	285	d = sdscatprintf(d, "%02x",digest[j]);
	286
	287	d = sdscatlen(d,"\r\n",2);
	288	addReplySds(c,d);
	289	} else {
	290	addReplySds(c,sdsnew(
	291	"-ERR Syntax error, try DEBUG [SEGFAULT\|OBJECT <key>\|SWAPIN <key>\|SWAPOUT <key>\|RELOAD]\r\n"));
	292	}
	293	}
	294
	295	void _redisAssert(char estr, char file, int line) {
	296	redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
	297	redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
	298	#ifdef HAVE_BACKTRACE
	299	redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
	300	((char)-1) = 'x';
	301	#endif
	302	}
	303
	304	void _redisPanic(char msg, char file, int line) {
	305	redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
	306	redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
	307	#ifdef HAVE_BACKTRACE
	308	redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
	309	((char)-1) = 'x';
	310	#endif
	311	}