src/redis-check-dump.c

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <string.h>
#include <arpa/inet.h>
#include <stdint.h>
#include <limits.h>
#include "lzf.h"

/* Object types */
#define REDIS_STRING 0
#define REDIS_LIST 1
#define REDIS_SET 2
#define REDIS_ZSET 3
#define REDIS_HASH 4

/* Objects encoding. Some kind of objects like Strings and Hashes can be
 * internally represented in multiple ways. The 'encoding' field of the object
 * is set to one of this fields for this object. */
#define REDIS_ENCODING_RAW 0    /* Raw representation */
#define REDIS_ENCODING_INT 1    /* Encoded as integer */
#define REDIS_ENCODING_ZIPMAP 2 /* Encoded as zipmap */
#define REDIS_ENCODING_HT 3     /* Encoded as an hash table */

/* Object types only used for dumping to disk */
#define REDIS_EXPIRETIME 253
#define REDIS_SELECTDB 254
#define REDIS_EOF 255

/* Defines related to the dump file format. To store 32 bits lengths for short
 * keys requires a lot of space, so we check the most significant 2 bits of
 * the first byte to interpreter the length:
 *
 * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
 * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
 * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
 * 11|000000 this means: specially encoded object will follow. The six bits
 *           number specify the kind of object that follows.
 *           See the REDIS_RDB_ENC_* defines.
 *
 * Lenghts up to 63 are stored using a single byte, most DB keys, and may
 * values, will fit inside. */
#define REDIS_RDB_6BITLEN 0
#define REDIS_RDB_14BITLEN 1
#define REDIS_RDB_32BITLEN 2
#define REDIS_RDB_ENCVAL 3
#define REDIS_RDB_LENERR UINT_MAX

/* When a length of a string object stored on disk has the first two bits
 * set, the remaining two bits specify a special encoding for the object
 * accordingly to the following defines: */
#define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
#define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
#define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
#define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */

#define ERROR(...) { \
    printf(__VA_ARGS__); \
    exit(1); \
}

/* data type to hold offset in file and size */
typedef struct {
    void *data;
    size_t size;
    size_t offset;
} pos;

static unsigned char level = 0;
static pos positions[16];

#define CURR_OFFSET (positions[level].offset)

/* Hold a stack of errors */
typedef struct {
    char error[16][1024];
    size_t offset[16];
    size_t level;
} errors_t;
static errors_t errors;

#define SHIFT_ERROR(provided_offset, ...) { \
    sprintf(errors.error[errors.level], __VA_ARGS__); \
    errors.offset[errors.level] = provided_offset; \
    errors.level++; \
}

/* Data type to hold opcode with optional key name an success status */
typedef struct {
    char* key;
    int type;
    char success;
} entry;

/* Global vars that are actally used as constants. The following double
 * values are used for double on-disk serialization, and are initialized
 * at runtime to avoid strange compiler optimizations. */
static double R_Zero, R_PosInf, R_NegInf, R_Nan;

/* store string types for output */
static char types[256][16];

/* when number of bytes to read is negative, do a peek */
int readBytes(void *target, long num) {
    char peek = (num < 0) ? 1 : 0;
    num = (num < 0) ? -num : num;

    pos p = positions[level];
    if (p.offset + num > p.size) {
        return 0;
    } else {
        memcpy(target, (void*)((size_t)p.data + p.offset), num);
        if (!peek) positions[level].offset += num;
    }
    return 1;
}

int processHeader() {
    char buf[10] = "_________";
    int dump_version;

    if (!readBytes(buf, 9)) {
        ERROR("Cannot read header\n");
    }

    /* expect the first 5 bytes to equal REDIS */
    if (memcmp(buf,"REDIS",5) != 0) {
        ERROR("Wrong signature in header\n");
    }

    dump_version = (int)strtol(buf + 5, NULL, 10);
    if (dump_version != 1) {
        ERROR("Unknown RDB format version: %d\n", dump_version);
    }
    return 1;
}

int loadType(entry *e) {
    uint32_t offset = CURR_OFFSET;

    /* this byte needs to qualify as type */
    unsigned char t;
    if (readBytes(&t, 1)) {
        if (t <= 4 || t >= 253) {
            e->type = t;
            return 1;
        } else {
            SHIFT_ERROR(offset, "Unknown type (0x%02x)", t);
        }
    } else {
        SHIFT_ERROR(offset, "Could not read type");
    }

    /* failure */
    return 0;
}

int peekType() {
    unsigned char t;
    if (readBytes(&t, -1) && (t <= 4 || t >= 253)) return t;
    return -1;
}

/* discard time, just consume the bytes */
int processTime() {
    uint32_t offset = CURR_OFFSET;
    unsigned char t[4];
    if (readBytes(t, 4)) {
        return 1;
    } else {
        SHIFT_ERROR(offset, "Could not read time");
    }

    /* failure */
    return 0;
}

uint32_t loadLength(int *isencoded) {
    unsigned char buf[2];
    uint32_t len;
    int type;

    if (isencoded) *isencoded = 0;
    if (!readBytes(buf, 1)) return REDIS_RDB_LENERR;
    type = (buf[0] & 0xC0) >> 6;
    if (type == REDIS_RDB_6BITLEN) {
        /* Read a 6 bit len */
        return buf[0] & 0x3F;
    } else if (type == REDIS_RDB_ENCVAL) {
        /* Read a 6 bit len encoding type */
        if (isencoded) *isencoded = 1;
        return buf[0] & 0x3F;
    } else if (type == REDIS_RDB_14BITLEN) {
        /* Read a 14 bit len */
        if (!readBytes(buf+1,1)) return REDIS_RDB_LENERR;
        return ((buf[0] & 0x3F) << 8) | buf[1];
    } else {
        /* Read a 32 bit len */
        if (!readBytes(&len, 4)) return REDIS_RDB_LENERR;
        return (unsigned int)ntohl(len);
    }
}

char *loadIntegerObject(int enctype) {
    uint32_t offset = CURR_OFFSET;
    unsigned char enc[4];
    long long val;

    if (enctype == REDIS_RDB_ENC_INT8) {
        uint8_t v;
        if (!readBytes(enc, 1)) return NULL;
        v = enc[0];
        val = (int8_t)v;
    } else if (enctype == REDIS_RDB_ENC_INT16) {
        uint16_t v;
        if (!readBytes(enc, 2)) return NULL;
        v = enc[0]|(enc[1]<<8);
        val = (int16_t)v;
    } else if (enctype == REDIS_RDB_ENC_INT32) {
        uint32_t v;
        if (!readBytes(enc, 4)) return NULL;
        v = enc[0]|(enc[1]<<8)|(enc[2]<<16)|(enc[3]<<24);
        val = (int32_t)v;
    } else {
        SHIFT_ERROR(offset, "Unknown integer encoding (0x%02x)", enctype);
        return NULL;
    }

    /* convert val into string */
    char *buf;
    buf = malloc(sizeof(char) * 128);
    sprintf(buf, "%lld", val);
    return buf;
}

char* loadLzfStringObject() {
    unsigned int slen, clen;
    char *c, *s;

    if ((clen = loadLength(NULL)) == REDIS_RDB_LENERR) return NULL;
    if ((slen = loadLength(NULL)) == REDIS_RDB_LENERR) return NULL;

    c = malloc(clen);
    if (!readBytes(c, clen)) {
        free(c);
        return NULL;
    }

    s = malloc(slen+1);
    if (lzf_decompress(c,clen,s,slen) == 0) {
        free(c); free(s);
        return NULL;
    }

    free(c);
    return s;
}

/* returns NULL when not processable, char* when valid */
char* loadStringObject() {
    uint32_t offset = CURR_OFFSET;
    int isencoded;
    uint32_t len;

    len = loadLength(&isencoded);
    if (isencoded) {
        switch(len) {
        case REDIS_RDB_ENC_INT8:
        case REDIS_RDB_ENC_INT16:
        case REDIS_RDB_ENC_INT32:
            return loadIntegerObject(len);
        case REDIS_RDB_ENC_LZF:
            return loadLzfStringObject();
        default:
            /* unknown encoding */
            SHIFT_ERROR(offset, "Unknown string encoding (0x%02x)", len);
            return NULL;
        }
    }

    if (len == REDIS_RDB_LENERR) return NULL;

    char *buf = malloc(sizeof(char) * (len+1));
    buf[len] = '\0';
    if (!readBytes(buf, len)) {
        free(buf);
        return NULL;
    }
    return buf;
}

int processStringObject(char** store) {
    unsigned long offset = CURR_OFFSET;
    char *key = loadStringObject();
    if (key == NULL) {
        SHIFT_ERROR(offset, "Error reading string object");
        free(key);
        return 0;
    }

    if (store != NULL) {
        *store = key;
    } else {
        free(key);
    }
    return 1;
}

double* loadDoubleValue() {
    char buf[256];
    unsigned char len;
    double* val;

    if (!readBytes(&len,1)) return NULL;

    val = malloc(sizeof(double));
    switch(len) {
    case 255: *val = R_NegInf;  return val;
    case 254: *val = R_PosInf;  return val;
    case 253: *val = R_Nan;     return val;
    default:
        if (!readBytes(buf, len)) {
            free(val);
            return NULL;
        }
        buf[len] = '\0';
        sscanf(buf, "%lg", val);
        return val;
    }
}

int processDoubleValue(double** store) {
    unsigned long offset = CURR_OFFSET;
    double *val = loadDoubleValue();
    if (val == NULL) {
        SHIFT_ERROR(offset, "Error reading double value");
        free(val);
        return 0;
    }

    if (store != NULL) {
        *store = val;
    } else {
        free(val);
    }
    return 1;
}

int loadPair(entry *e) {
    uint32_t offset = CURR_OFFSET;
    uint32_t i;

    /* read key first */
    char *key;
    if (processStringObject(&key)) {
        e->key = key;
    } else {
        SHIFT_ERROR(offset, "Error reading entry key");
        return 0;
    }

    uint32_t length = 0;
    if (e->type == REDIS_LIST ||
        e->type == REDIS_SET  ||
        e->type == REDIS_ZSET ||
        e->type == REDIS_HASH) {
        if ((length = loadLength(NULL)) == REDIS_RDB_LENERR) {
            SHIFT_ERROR(offset, "Error reading %s length", types[e->type]);
            return 0;
        }
    }

    switch(e->type) {
    case REDIS_STRING:
        if (!processStringObject(NULL)) {
            SHIFT_ERROR(offset, "Error reading entry value");
            return 0;
        }
    break;
    case REDIS_LIST:
    case REDIS_SET:
        for (i = 0; i < length; i++) {
            offset = CURR_OFFSET;
            if (!processStringObject(NULL)) {
                SHIFT_ERROR(offset, "Error reading element at index %d (length: %d)", i, length);
                return 0;
            }
        }
    break;
    case REDIS_ZSET:
        for (i = 0; i < length; i++) {
            offset = CURR_OFFSET;
            if (!processStringObject(NULL)) {
                SHIFT_ERROR(offset, "Error reading element key at index %d (length: %d)", i, length);
                return 0;
            }
            offset = CURR_OFFSET;
            if (!processDoubleValue(NULL)) {
                SHIFT_ERROR(offset, "Error reading element value at index %d (length: %d)", i, length);
                return 0;
            }
        }
    break;
    case REDIS_HASH:
        for (i = 0; i < length; i++) {
            offset = CURR_OFFSET;
            if (!processStringObject(NULL)) {
                SHIFT_ERROR(offset, "Error reading element key at index %d (length: %d)", i, length);
                return 0;
            }
            offset = CURR_OFFSET;
            if (!processStringObject(NULL)) {
                SHIFT_ERROR(offset, "Error reading element value at index %d (length: %d)", i, length);
                return 0;
            }
        }
    break;
    default:
        SHIFT_ERROR(offset, "Type not implemented");
        return 0;
    }
    /* because we're done, we assume success */
    e->success = 1;
    return 1;
}

entry loadEntry() {
    entry e = { NULL, -1, 0 };
    uint32_t length, offset[4];

    /* reset error container */
    errors.level = 0;

    offset[0] = CURR_OFFSET;
    if (!loadType(&e)) {
        return e;
    }

    offset[1] = CURR_OFFSET;
    if (e.type == REDIS_SELECTDB) {
        if ((length = loadLength(NULL)) == REDIS_RDB_LENERR) {
            SHIFT_ERROR(offset[1], "Error reading database number");
            return e;
        }
        if (length > 63) {
            SHIFT_ERROR(offset[1], "Database number out of range (%d)", length);
            return e;
        }
    } else if (e.type == REDIS_EOF) {
        if (positions[level].offset < positions[level].size) {
            SHIFT_ERROR(offset[0], "Unexpected EOF");
        } else {
            e.success = 1;
        }
        return e;
    } else {
        /* optionally consume expire */
        if (e.type == REDIS_EXPIRETIME) {
            if (!processTime()) return e;
            if (!loadType(&e)) return e;
        }

        offset[1] = CURR_OFFSET;
        if (!loadPair(&e)) {
            SHIFT_ERROR(offset[1], "Error for type %s", types[e.type]);
            return e;
        }
    }

    /* all entries are followed by a valid type:
     * e.g. a new entry, SELECTDB, EXPIRE, EOF */
    offset[2] = CURR_OFFSET;
    if (peekType() == -1) {
        SHIFT_ERROR(offset[2], "Followed by invalid type");
        SHIFT_ERROR(offset[0], "Error for type %s", types[e.type]);
        e.success = 0;
    } else {
        e.success = 1;
    }

    return e;
}

void printCentered(int indent, int width, char* body) {
    char head[256], tail[256];
    memset(head, '\0', 256);
    memset(tail, '\0', 256);

    memset(head, '=', indent);
    memset(tail, '=', width - 2 - indent - strlen(body));
    printf("%s %s %s\n", head, body, tail);
}

void printValid(uint64_t ops, uint64_t bytes) {
    char body[80];
    sprintf(body, "Processed %llu valid opcodes (in %llu bytes)",
        (unsigned long long) ops, (unsigned long long) bytes);
    printCentered(4, 80, body);
}

void printSkipped(uint64_t bytes, uint64_t offset) {
    char body[80];
    sprintf(body, "Skipped %llu bytes (resuming at 0x%08llx)",
        (unsigned long long) bytes, (unsigned long long) offset);
    printCentered(4, 80, body);
}

void printErrorStack(entry *e) {
    unsigned int i;
    char body[64];

    if (e->type == -1) {
        sprintf(body, "Error trace");
    } else if (e->type >= 253) {
        sprintf(body, "Error trace (%s)", types[e->type]);
    } else if (!e->key) {
        sprintf(body, "Error trace (%s: (unknown))", types[e->type]);
    } else {
        char tmp[41];
        strncpy(tmp, e->key, 40);

        /* display truncation at the last 3 chars */
        if (strlen(e->key) > 40) {
            memset(&tmp[37], '.', 3);
        }

        /* display unprintable characters as ? */
        for (i = 0; i < strlen(tmp); i++) {
            if (tmp[i] <= 32) tmp[i] = '?';
        }
        sprintf(body, "Error trace (%s: %s)", types[e->type], tmp);
    }

    printCentered(4, 80, body);

    /* display error stack */
    for (i = 0; i < errors.level; i++) {
        printf("0x%08lx - %s\n", errors.offset[i], errors.error[i]);
    }
}

void process() {
    uint64_t num_errors = 0, num_valid_ops = 0, num_valid_bytes = 0;
    entry entry;
    processHeader();

    level = 1;
    while(positions[0].offset < positions[0].size) {
        positions[1] = positions[0];

        entry = loadEntry();
        if (!entry.success) {
            printValid(num_valid_ops, num_valid_bytes);
            printErrorStack(&entry);
            num_errors++;
            num_valid_ops = 0;
            num_valid_bytes = 0;

            /* search for next valid entry */
            uint64_t offset = positions[0].offset + 1;
            int i = 0;

            while (!entry.success && offset < positions[0].size) {
                positions[1].offset = offset;

                /* find 3 consecutive valid entries */
                for (i = 0; i < 3; i++) {
                    entry = loadEntry();
                    if (!entry.success) break;
                }
                /* check if we found 3 consecutive valid entries */
                if (i < 3) {
                    offset++;
                }
            }

            /* print how many bytes we have skipped to find a new valid opcode */
            if (offset < positions[0].size) {
                printSkipped(offset - positions[0].offset, offset);
            }

            positions[0].offset = offset;
        } else {
            num_valid_ops++;
            num_valid_bytes += positions[1].offset - positions[0].offset;

            /* advance position */
            positions[0] = positions[1];
        }
    }

    /* because there is another potential error,
     * print how many valid ops we have processed */
    printValid(num_valid_ops, num_valid_bytes);

    /* expect an eof */
    if (entry.type != REDIS_EOF) {
        /* last byte should be EOF, add error */
        errors.level = 0;
        SHIFT_ERROR(positions[0].offset, "Expected EOF, got %s", types[entry.type]);

        /* this is an EOF error so reset type */
        entry.type = -1;
        printErrorStack(&entry);

        num_errors++;
    }

    /* print summary on errors */
    if (num_errors) {
        printf("\n");
        printf("Total unprocessable opcodes: %llu\n",
            (unsigned long long) num_errors);
    }
}

int main(int argc, char **argv) {
    /* expect the first argument to be the dump file */
    if (argc <= 1) {
        printf("Usage: %s <dump.rdb>\n", argv[0]);
        exit(0);
    }

    int fd;
    off_t size;
    struct stat stat;
    void *data;

    fd = open(argv[1], O_RDONLY);
    if (fd < 1) {
        ERROR("Cannot open file: %s\n", argv[1]);
    }
    if (fstat(fd, &stat) == -1) {
        ERROR("Cannot stat: %s\n", argv[1]);
    } else {
        size = stat.st_size;
    }

    if (sizeof(size_t) == sizeof(int32_t) && size >= INT_MAX) {
        ERROR("Cannot check dump files >2GB on a 32-bit platform\n");
    }

    data = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
    if (data == MAP_FAILED) {
        ERROR("Cannot mmap: %s\n", argv[1]);
    }

    /* Initialize static vars */
    positions[0].data = data;
    positions[0].size = size;
    positions[0].offset = 0;
    errors.level = 0;

    /* Object types */
    sprintf(types[REDIS_STRING], "STRING");
    sprintf(types[REDIS_LIST], "LIST");
    sprintf(types[REDIS_SET], "SET");
    sprintf(types[REDIS_ZSET], "ZSET");
    sprintf(types[REDIS_HASH], "HASH");

    /* Object types only used for dumping to disk */
    sprintf(types[REDIS_EXPIRETIME], "EXPIRETIME");
    sprintf(types[REDIS_SELECTDB], "SELECTDB");
    sprintf(types[REDIS_EOF], "EOF");

    /* Double constants initialization */
    R_Zero = 0.0;
    R_PosInf = 1.0/R_Zero;
    R_NegInf = -1.0/R_Zero;
    R_Nan = R_Zero/R_Zero;

    process();

    munmap(data, size);
    close(fd);
    return 0;
}
Commit	Line	Data
	1	#include <stdlib.h>
	2	#include <stdio.h>
	3	#include <unistd.h>
	4	#include <fcntl.h>
	5	#include <sys/stat.h>
	6	#include <sys/mman.h>
	7	#include <string.h>
	8	#include <arpa/inet.h>
	9	#include <stdint.h>
	10	#include <limits.h>
	11	#include "lzf.h"
	12
	13	/* Object types */
	14	#define REDIS_STRING 0
	15	#define REDIS_LIST 1
	16	#define REDIS_SET 2
	17	#define REDIS_ZSET 3
	18	#define REDIS_HASH 4
	19
	20	/* Objects encoding. Some kind of objects like Strings and Hashes can be
	21	* internally represented in multiple ways. The 'encoding' field of the object
	22	* is set to one of this fields for this object. */
	23	#define REDIS_ENCODING_RAW 0 /* Raw representation */
	24	#define REDIS_ENCODING_INT 1 /* Encoded as integer */
	25	#define REDIS_ENCODING_ZIPMAP 2 /* Encoded as zipmap */
	26	#define REDIS_ENCODING_HT 3 /* Encoded as an hash table */
	27
	28	/* Object types only used for dumping to disk */
	29	#define REDIS_EXPIRETIME 253
	30	#define REDIS_SELECTDB 254
	31	#define REDIS_EOF 255
	32
	33	/* Defines related to the dump file format. To store 32 bits lengths for short
	34	* keys requires a lot of space, so we check the most significant 2 bits of
	35	* the first byte to interpreter the length:
	36	*
	37	* 00\|000000 => if the two MSB are 00 the len is the 6 bits of this byte
	38	* 01\|000000 00000000 => 01, the len is 14 byes, 6 bits + 8 bits of next byte
	39	* 10\|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
	40	* 11\|000000 this means: specially encoded object will follow. The six bits
	41	* number specify the kind of object that follows.
	42	* See the REDIS_RDB_ENC_* defines.
	43	*
	44	* Lenghts up to 63 are stored using a single byte, most DB keys, and may
	45	* values, will fit inside. */
	46	#define REDIS_RDB_6BITLEN 0
	47	#define REDIS_RDB_14BITLEN 1
	48	#define REDIS_RDB_32BITLEN 2
	49	#define REDIS_RDB_ENCVAL 3
	50	#define REDIS_RDB_LENERR UINT_MAX
	51
	52	/* When a length of a string object stored on disk has the first two bits
	53	* set, the remaining two bits specify a special encoding for the object
	54	* accordingly to the following defines: */
	55	#define REDIS_RDB_ENC_INT8 0 /* 8 bit signed integer */
	56	#define REDIS_RDB_ENC_INT16 1 /* 16 bit signed integer */
	57	#define REDIS_RDB_ENC_INT32 2 /* 32 bit signed integer */
	58	#define REDIS_RDB_ENC_LZF 3 /* string compressed with FASTLZ */
	59
	60	#define ERROR(...) { \
	61	printf(__VA_ARGS__); \
	62	exit(1); \
	63	}
	64
	65	/* data type to hold offset in file and size */
	66	typedef struct {
	67	void *data;
	68	size_t size;
	69	size_t offset;
	70	} pos;
	71
	72	static unsigned char level = 0;
	73	static pos positions[16];
	74
	75	#define CURR_OFFSET (positions[level].offset)
	76
	77	/* Hold a stack of errors */
	78	typedef struct {
	79	char error[16][1024];
	80	size_t offset[16];
	81	size_t level;
	82	} errors_t;
	83	static errors_t errors;
	84
	85	#define SHIFT_ERROR(provided_offset, ...) { \
	86	sprintf(errors.error[errors.level], __VA_ARGS__); \
	87	errors.offset[errors.level] = provided_offset; \
	88	errors.level++; \
	89	}
	90
	91	/* Data type to hold opcode with optional key name an success status */
	92	typedef struct {
	93	char* key;
	94	int type;
	95	char success;
	96	} entry;
	97
	98	/* Global vars that are actally used as constants. The following double
	99	* values are used for double on-disk serialization, and are initialized
	100	* at runtime to avoid strange compiler optimizations. */
	101	static double R_Zero, R_PosInf, R_NegInf, R_Nan;
	102
	103	/* store string types for output */
	104	static char types[256][16];
	105
	106	/* when number of bytes to read is negative, do a peek */
	107	int readBytes(void *target, long num) {
	108	char peek = (num < 0) ? 1 : 0;
	109	num = (num < 0) ? -num : num;
	110
	111	pos p = positions[level];
	112	if (p.offset + num > p.size) {
	113	return 0;
	114	} else {
	115	memcpy(target, (void*)((size_t)p.data + p.offset), num);
	116	if (!peek) positions[level].offset += num;
	117	}
	118	return 1;
	119	}
	120
	121	int processHeader() {
	122	char buf[10] = "_________";
	123	int dump_version;
	124
	125	if (!readBytes(buf, 9)) {
	126	ERROR("Cannot read header\n");
	127	}
	128
	129	/* expect the first 5 bytes to equal REDIS */
	130	if (memcmp(buf,"REDIS",5) != 0) {
	131	ERROR("Wrong signature in header\n");
	132	}
	133
	134	dump_version = (int)strtol(buf + 5, NULL, 10);
	135	if (dump_version != 1) {
	136	ERROR("Unknown RDB format version: %d\n", dump_version);
	137	}
	138	return 1;
	139	}
	140
	141	int loadType(entry *e) {
	142	uint32_t offset = CURR_OFFSET;
	143
	144	/* this byte needs to qualify as type */
	145	unsigned char t;
	146	if (readBytes(&t, 1)) {
	147	if (t <= 4 \|\| t >= 253) {
	148	e->type = t;
	149	return 1;
	150	} else {
	151	SHIFT_ERROR(offset, "Unknown type (0x%02x)", t);
	152	}
	153	} else {
	154	SHIFT_ERROR(offset, "Could not read type");
	155	}
	156
	157	/* failure */
	158	return 0;
	159	}
	160
	161	int peekType() {
	162	unsigned char t;
	163	if (readBytes(&t, -1) && (t <= 4 \|\| t >= 253)) return t;
	164	return -1;
	165	}
	166
	167	/* discard time, just consume the bytes */
	168	int processTime() {
	169	uint32_t offset = CURR_OFFSET;
	170	unsigned char t[4];
	171	if (readBytes(t, 4)) {
	172	return 1;
	173	} else {
	174	SHIFT_ERROR(offset, "Could not read time");
	175	}
	176
	177	/* failure */
	178	return 0;
	179	}
	180
	181	uint32_t loadLength(int *isencoded) {
	182	unsigned char buf[2];
	183	uint32_t len;
	184	int type;
	185
	186	if (isencoded) *isencoded = 0;
	187	if (!readBytes(buf, 1)) return REDIS_RDB_LENERR;
	188	type = (buf[0] & 0xC0) >> 6;
	189	if (type == REDIS_RDB_6BITLEN) {
	190	/* Read a 6 bit len */
	191	return buf[0] & 0x3F;
	192	} else if (type == REDIS_RDB_ENCVAL) {
	193	/* Read a 6 bit len encoding type */
	194	if (isencoded) *isencoded = 1;
	195	return buf[0] & 0x3F;
	196	} else if (type == REDIS_RDB_14BITLEN) {
	197	/* Read a 14 bit len */
	198	if (!readBytes(buf+1,1)) return REDIS_RDB_LENERR;
	199	return ((buf[0] & 0x3F) << 8) \| buf[1];
	200	} else {
	201	/* Read a 32 bit len */
	202	if (!readBytes(&len, 4)) return REDIS_RDB_LENERR;
	203	return (unsigned int)ntohl(len);
	204	}
	205	}
	206
	207	char *loadIntegerObject(int enctype) {
	208	uint32_t offset = CURR_OFFSET;
	209	unsigned char enc[4];
	210	long long val;
	211
	212	if (enctype == REDIS_RDB_ENC_INT8) {
	213	uint8_t v;
	214	if (!readBytes(enc, 1)) return NULL;
	215	v = enc[0];
	216	val = (int8_t)v;
	217	} else if (enctype == REDIS_RDB_ENC_INT16) {
	218	uint16_t v;
	219	if (!readBytes(enc, 2)) return NULL;
	220	v = enc[0]\|(enc[1]<<8);
	221	val = (int16_t)v;
	222	} else if (enctype == REDIS_RDB_ENC_INT32) {
	223	uint32_t v;
	224	if (!readBytes(enc, 4)) return NULL;
	225	v = enc[0]\|(enc[1]<<8)\|(enc[2]<<16)\|(enc[3]<<24);
	226	val = (int32_t)v;
	227	} else {
	228	SHIFT_ERROR(offset, "Unknown integer encoding (0x%02x)", enctype);
	229	return NULL;
	230	}
	231
	232	/* convert val into string */
	233	char *buf;
	234	buf = malloc(sizeof(char) * 128);
	235	sprintf(buf, "%lld", val);
	236	return buf;
	237	}
	238
	239	char* loadLzfStringObject() {
	240	unsigned int slen, clen;
	241	char c, s;
	242
	243	if ((clen = loadLength(NULL)) == REDIS_RDB_LENERR) return NULL;
	244	if ((slen = loadLength(NULL)) == REDIS_RDB_LENERR) return NULL;
	245
	246	c = malloc(clen);
	247	if (!readBytes(c, clen)) {
	248	free(c);
	249	return NULL;
	250	}
	251
	252	s = malloc(slen+1);
	253	if (lzf_decompress(c,clen,s,slen) == 0) {
	254	free(c); free(s);
	255	return NULL;
	256	}
	257
	258	free(c);
	259	return s;
	260	}
	261
	262	/* returns NULL when not processable, char* when valid */
	263	char* loadStringObject() {
	264	uint32_t offset = CURR_OFFSET;
	265	int isencoded;
	266	uint32_t len;
	267
	268	len = loadLength(&isencoded);
	269	if (isencoded) {
	270	switch(len) {
	271	case REDIS_RDB_ENC_INT8:
	272	case REDIS_RDB_ENC_INT16:
	273	case REDIS_RDB_ENC_INT32:
	274	return loadIntegerObject(len);
	275	case REDIS_RDB_ENC_LZF:
	276	return loadLzfStringObject();
	277	default:
	278	/* unknown encoding */
	279	SHIFT_ERROR(offset, "Unknown string encoding (0x%02x)", len);
	280	return NULL;
	281	}
	282	}
	283
	284	if (len == REDIS_RDB_LENERR) return NULL;
	285
	286	char buf = malloc(sizeof(char) (len+1));
	287	buf[len] = '\0';
	288	if (!readBytes(buf, len)) {
	289	free(buf);
	290	return NULL;
	291	}
	292	return buf;
	293	}
	294
	295	int processStringObject(char** store) {
	296	unsigned long offset = CURR_OFFSET;
	297	char *key = loadStringObject();
	298	if (key == NULL) {
	299	SHIFT_ERROR(offset, "Error reading string object");
	300	free(key);
	301	return 0;
	302	}
	303
	304	if (store != NULL) {
	305	*store = key;
	306	} else {
	307	free(key);
	308	}
	309	return 1;
	310	}
	311
	312	double* loadDoubleValue() {
	313	char buf[256];
	314	unsigned char len;
	315	double* val;
	316
	317	if (!readBytes(&len,1)) return NULL;
	318
	319	val = malloc(sizeof(double));
	320	switch(len) {
	321	case 255: *val = R_NegInf; return val;
	322	case 254: *val = R_PosInf; return val;
	323	case 253: *val = R_Nan; return val;
	324	default:
	325	if (!readBytes(buf, len)) {
	326	free(val);
	327	return NULL;
	328	}
	329	buf[len] = '\0';
	330	sscanf(buf, "%lg", val);
	331	return val;
	332	}
	333	}
	334
	335	int processDoubleValue(double** store) {
	336	unsigned long offset = CURR_OFFSET;
	337	double *val = loadDoubleValue();
	338	if (val == NULL) {
	339	SHIFT_ERROR(offset, "Error reading double value");
	340	free(val);
	341	return 0;
	342	}
	343
	344	if (store != NULL) {
	345	*store = val;
	346	} else {
	347	free(val);
	348	}
	349	return 1;
	350	}
	351
	352	int loadPair(entry *e) {
	353	uint32_t offset = CURR_OFFSET;
	354	uint32_t i;
	355
	356	/* read key first */
	357	char *key;
	358	if (processStringObject(&key)) {
	359	e->key = key;
	360	} else {
	361	SHIFT_ERROR(offset, "Error reading entry key");
	362	return 0;
	363	}
	364
	365	uint32_t length = 0;
	366	if (e->type == REDIS_LIST \|\|
	367	e->type == REDIS_SET \|\|
	368	e->type == REDIS_ZSET \|\|
	369	e->type == REDIS_HASH) {
	370	if ((length = loadLength(NULL)) == REDIS_RDB_LENERR) {
	371	SHIFT_ERROR(offset, "Error reading %s length", types[e->type]);
	372	return 0;
	373	}
	374	}
	375
	376	switch(e->type) {
	377	case REDIS_STRING:
	378	if (!processStringObject(NULL)) {
	379	SHIFT_ERROR(offset, "Error reading entry value");
	380	return 0;
	381	}
	382	break;
	383	case REDIS_LIST:
	384	case REDIS_SET:
	385	for (i = 0; i < length; i++) {
	386	offset = CURR_OFFSET;
	387	if (!processStringObject(NULL)) {
	388	SHIFT_ERROR(offset, "Error reading element at index %d (length: %d)", i, length);
	389	return 0;
	390	}
	391	}
	392	break;
	393	case REDIS_ZSET:
	394	for (i = 0; i < length; i++) {
	395	offset = CURR_OFFSET;
	396	if (!processStringObject(NULL)) {
	397	SHIFT_ERROR(offset, "Error reading element key at index %d (length: %d)", i, length);
	398	return 0;
	399	}
	400	offset = CURR_OFFSET;
	401	if (!processDoubleValue(NULL)) {
	402	SHIFT_ERROR(offset, "Error reading element value at index %d (length: %d)", i, length);
	403	return 0;
	404	}
	405	}
	406	break;
	407	case REDIS_HASH:
	408	for (i = 0; i < length; i++) {
	409	offset = CURR_OFFSET;
	410	if (!processStringObject(NULL)) {
	411	SHIFT_ERROR(offset, "Error reading element key at index %d (length: %d)", i, length);
	412	return 0;
	413	}
	414	offset = CURR_OFFSET;
	415	if (!processStringObject(NULL)) {
	416	SHIFT_ERROR(offset, "Error reading element value at index %d (length: %d)", i, length);
	417	return 0;
	418	}
	419	}
	420	break;
	421	default:
	422	SHIFT_ERROR(offset, "Type not implemented");
	423	return 0;
	424	}
	425	/* because we're done, we assume success */
	426	e->success = 1;
	427	return 1;
	428	}
	429
	430	entry loadEntry() {
	431	entry e = { NULL, -1, 0 };
	432	uint32_t length, offset[4];
	433
	434	/* reset error container */
	435	errors.level = 0;
	436
	437	offset[0] = CURR_OFFSET;
	438	if (!loadType(&e)) {
	439	return e;
	440	}
	441
	442	offset[1] = CURR_OFFSET;
	443	if (e.type == REDIS_SELECTDB) {
	444	if ((length = loadLength(NULL)) == REDIS_RDB_LENERR) {
	445	SHIFT_ERROR(offset[1], "Error reading database number");
	446	return e;
	447	}
	448	if (length > 63) {
	449	SHIFT_ERROR(offset[1], "Database number out of range (%d)", length);
	450	return e;
	451	}
	452	} else if (e.type == REDIS_EOF) {
	453	if (positions[level].offset < positions[level].size) {
	454	SHIFT_ERROR(offset[0], "Unexpected EOF");
	455	} else {
	456	e.success = 1;
	457	}
	458	return e;
	459	} else {
	460	/* optionally consume expire */
	461	if (e.type == REDIS_EXPIRETIME) {
	462	if (!processTime()) return e;
	463	if (!loadType(&e)) return e;
	464	}
	465
	466	offset[1] = CURR_OFFSET;
	467	if (!loadPair(&e)) {
	468	SHIFT_ERROR(offset[1], "Error for type %s", types[e.type]);
	469	return e;
	470	}
	471	}
	472
	473	/* all entries are followed by a valid type:
	474	* e.g. a new entry, SELECTDB, EXPIRE, EOF */
	475	offset[2] = CURR_OFFSET;
	476	if (peekType() == -1) {
	477	SHIFT_ERROR(offset[2], "Followed by invalid type");
	478	SHIFT_ERROR(offset[0], "Error for type %s", types[e.type]);
	479	e.success = 0;
	480	} else {
	481	e.success = 1;
	482	}
	483
	484	return e;
	485	}
	486
	487	void printCentered(int indent, int width, char* body) {
	488	char head[256], tail[256];
	489	memset(head, '\0', 256);
	490	memset(tail, '\0', 256);
	491
	492	memset(head, '=', indent);
	493	memset(tail, '=', width - 2 - indent - strlen(body));
	494	printf("%s %s %s\n", head, body, tail);
	495	}
	496
	497	void printValid(uint64_t ops, uint64_t bytes) {
	498	char body[80];
	499	sprintf(body, "Processed %llu valid opcodes (in %llu bytes)",
	500	(unsigned long long) ops, (unsigned long long) bytes);
	501	printCentered(4, 80, body);
	502	}
	503
	504	void printSkipped(uint64_t bytes, uint64_t offset) {
	505	char body[80];
	506	sprintf(body, "Skipped %llu bytes (resuming at 0x%08llx)",
	507	(unsigned long long) bytes, (unsigned long long) offset);
	508	printCentered(4, 80, body);
	509	}
	510
	511	void printErrorStack(entry *e) {
	512	unsigned int i;
	513	char body[64];
	514
	515	if (e->type == -1) {
	516	sprintf(body, "Error trace");
	517	} else if (e->type >= 253) {
	518	sprintf(body, "Error trace (%s)", types[e->type]);
	519	} else if (!e->key) {
	520	sprintf(body, "Error trace (%s: (unknown))", types[e->type]);
	521	} else {
	522	char tmp[41];
	523	strncpy(tmp, e->key, 40);
	524
	525	/* display truncation at the last 3 chars */
	526	if (strlen(e->key) > 40) {
	527	memset(&tmp[37], '.', 3);
	528	}
	529
	530	/* display unprintable characters as ? */
	531	for (i = 0; i < strlen(tmp); i++) {
	532	if (tmp[i] <= 32) tmp[i] = '?';
	533	}
	534	sprintf(body, "Error trace (%s: %s)", types[e->type], tmp);
	535	}
	536
	537	printCentered(4, 80, body);
	538
	539	/* display error stack */
	540	for (i = 0; i < errors.level; i++) {
	541	printf("0x%08lx - %s\n", errors.offset[i], errors.error[i]);
	542	}
	543	}
	544
	545	void process() {
	546	uint64_t num_errors = 0, num_valid_ops = 0, num_valid_bytes = 0;
	547	entry entry;
	548	processHeader();
	549
	550	level = 1;
	551	while(positions[0].offset < positions[0].size) {
	552	positions[1] = positions[0];
	553
	554	entry = loadEntry();
	555	if (!entry.success) {
	556	printValid(num_valid_ops, num_valid_bytes);
	557	printErrorStack(&entry);
	558	num_errors++;
	559	num_valid_ops = 0;
	560	num_valid_bytes = 0;
	561
	562	/* search for next valid entry */
	563	uint64_t offset = positions[0].offset + 1;
	564	int i = 0;
	565
	566	while (!entry.success && offset < positions[0].size) {
	567	positions[1].offset = offset;
	568
	569	/* find 3 consecutive valid entries */
	570	for (i = 0; i < 3; i++) {
	571	entry = loadEntry();
	572	if (!entry.success) break;
	573	}
	574	/* check if we found 3 consecutive valid entries */
	575	if (i < 3) {
	576	offset++;
	577	}
	578	}
	579
	580	/* print how many bytes we have skipped to find a new valid opcode */
	581	if (offset < positions[0].size) {
	582	printSkipped(offset - positions[0].offset, offset);
	583	}
	584
	585	positions[0].offset = offset;
	586	} else {
	587	num_valid_ops++;
	588	num_valid_bytes += positions[1].offset - positions[0].offset;
	589
	590	/* advance position */
	591	positions[0] = positions[1];
	592	}
	593	}
	594
	595	/* because there is another potential error,
	596	* print how many valid ops we have processed */
	597	printValid(num_valid_ops, num_valid_bytes);
	598
	599	/* expect an eof */
	600	if (entry.type != REDIS_EOF) {
	601	/* last byte should be EOF, add error */
	602	errors.level = 0;
	603	SHIFT_ERROR(positions[0].offset, "Expected EOF, got %s", types[entry.type]);
	604
	605	/* this is an EOF error so reset type */
	606	entry.type = -1;
	607	printErrorStack(&entry);
	608
	609	num_errors++;
	610	}
	611
	612	/* print summary on errors */
	613	if (num_errors) {
	614	printf("\n");
	615	printf("Total unprocessable opcodes: %llu\n",
	616	(unsigned long long) num_errors);
	617	}
	618	}
	619
	620	int main(int argc, char **argv) {
	621	/* expect the first argument to be the dump file */
	622	if (argc <= 1) {
	623	printf("Usage: %s <dump.rdb>\n", argv[0]);
	624	exit(0);
	625	}
	626
	627	int fd;
	628	off_t size;
	629	struct stat stat;
	630	void *data;
	631
	632	fd = open(argv[1], O_RDONLY);
	633	if (fd < 1) {
	634	ERROR("Cannot open file: %s\n", argv[1]);
	635	}
	636	if (fstat(fd, &stat) == -1) {
	637	ERROR("Cannot stat: %s\n", argv[1]);
	638	} else {
	639	size = stat.st_size;
	640	}
	641
	642	if (sizeof(size_t) == sizeof(int32_t) && size >= INT_MAX) {
	643	ERROR("Cannot check dump files >2GB on a 32-bit platform\n");
	644	}
	645
	646	data = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
	647	if (data == MAP_FAILED) {
	648	ERROR("Cannot mmap: %s\n", argv[1]);
	649	}
	650
	651	/* Initialize static vars */
	652	positions[0].data = data;
	653	positions[0].size = size;
	654	positions[0].offset = 0;
	655	errors.level = 0;
	656
	657	/* Object types */
	658	sprintf(types[REDIS_STRING], "STRING");
	659	sprintf(types[REDIS_LIST], "LIST");
	660	sprintf(types[REDIS_SET], "SET");
	661	sprintf(types[REDIS_ZSET], "ZSET");
	662	sprintf(types[REDIS_HASH], "HASH");
	663
	664	/* Object types only used for dumping to disk */
	665	sprintf(types[REDIS_EXPIRETIME], "EXPIRETIME");
	666	sprintf(types[REDIS_SELECTDB], "SELECTDB");
	667	sprintf(types[REDIS_EOF], "EOF");
	668
	669	/* Double constants initialization */
	670	R_Zero = 0.0;
	671	R_PosInf = 1.0/R_Zero;
	672	R_NegInf = -1.0/R_Zero;
	673	R_Nan = R_Zero/R_Zero;
	674
	675	process();
	676
	677	munmap(data, size);
	678	close(fd);
	679	return 0;
	680	}