Sentinel: reply -IDONTKNOW to get-master-addr-by-name on lack of info.

[redis.git] / src / rdb.c

diff --git a/src/rdb.c b/src/rdb.c
index 3667f279efea2cf60143dd6736a124fa5db893b8..90c2ea0843fef07fdc733ec3be7cd2fb67d554da 100644 (file)
--- a/src/rdb.c
+++ b/src/rdb.c
@@ -1,6 +1,7 @@
 #include "redis.h"
 #include "lzf.h"    /* LZF compression library */
 #include "zipmap.h"
+#include "endianconv.h"
 
 #include <math.h>
 #include <sys/types.h>
@@ -20,6 +21,9 @@ int rdbSaveType(rio *rdb, unsigned char type) {
     return rdbWriteRaw(rdb,&type,1);
 }
 
+/* Load a "type" in RDB format, that is a one byte unsigned integer.
+ * This function is not only used to load object types, but also special
+ * "types" like the end-of-file type, the EXPIRE type, and so forth. */
 int rdbLoadType(rio *rdb) {
     unsigned char type;
     if (rioRead(rdb,&type,1) == 0) return -1;
@@ -432,7 +436,8 @@ int rdbSaveObjectType(rio *rdb, robj *o) {
     return -1; /* avoid warning */
 }
 
-/* Load object type. Return -1 when the byte doesn't contain an object type. */
+/* Use rdbLoadType() to load a TYPE in RDB format, but returns -1 if the
+ * type is not specifically a valid Object Type. */
 int rdbLoadObjectType(rio *rdb) {
     int type;
     if ((type = rdbLoadType(rdb)) == -1) return -1;
@@ -602,6 +607,7 @@ int rdbSave(char *filename) {
     long long now = mstime();
     FILE *fp;
     rio rdb;
+    uint64_t cksum;
 
     snprintf(tmpfile,256,"temp-%d.rdb", (int) getpid());
     fp = fopen(tmpfile,"w");
@@ -612,6 +618,8 @@ int rdbSave(char *filename) {
     }
 
     rioInitWithFile(&rdb,fp);
+    if (server.rdb_checksum)
+        rdb.update_cksum = rioGenericUpdateChecksum;
     snprintf(magic,sizeof(magic),"REDIS%04d",REDIS_RDB_VERSION);
     if (rdbWriteRaw(&rdb,magic,9) == -1) goto werr;
 
@@ -641,9 +649,17 @@ int rdbSave(char *filename) {
         }
         dictReleaseIterator(di);
     }
+    di = NULL; /* So that we don't release it again on error. */
+
     /* EOF opcode */
     if (rdbSaveType(&rdb,REDIS_RDB_OPCODE_EOF) == -1) goto werr;
 
+    /* CRC64 checksum. It will be zero if checksum computation is disabled, the
+     * loading code skips the check in this case. */
+    cksum = rdb.cksum;
+    memrev64ifbe(&cksum);
+    rioWrite(&rdb,&cksum,8);
+
     /* Make sure data will not remain on the OS's output buffers */
     fflush(fp);
     fsync(fileno(fp));
@@ -696,6 +712,7 @@ int rdbSaveBackground(char *filename) {
             return REDIS_ERR;
         }
         redisLog(REDIS_NOTICE,"Background saving started by pid %d",childpid);
+        server.rdb_save_time_start = time(NULL);
         server.rdb_child_pid = childpid;
         updateDictResizePolicy();
         return REDIS_OK;
@@ -1016,6 +1033,8 @@ int rdbLoad(char *filename) {
         return REDIS_ERR;
     }
     rioInitWithFile(&rdb,fp);
+    if (server.rdb_checksum)
+        rdb.update_cksum = rioGenericUpdateChecksum;
     if (rioRead(&rdb,buf,9) == 0) goto eoferr;
     buf[9] = '\0';
     if (memcmp(buf,"REDIS",5) != 0) {
@@ -1025,7 +1044,7 @@ int rdbLoad(char *filename) {
         return REDIS_ERR;
     }
     rdbver = atoi(buf+5);
-    if (rdbver < 1 || rdbver > 4) {
+    if (rdbver < 1 || rdbver > REDIS_RDB_VERSION) {
         fclose(fp);
         redisLog(REDIS_WARNING,"Can't handle RDB format version %d",rdbver);
         errno = EINVAL;
@@ -1096,6 +1115,20 @@ int rdbLoad(char *filename) {
 
         decrRefCount(key);
     }
+    /* Verify the checksum if RDB version is >= 5 */
+    if (rdbver >= 5 && server.rdb_checksum) {
+        uint64_t cksum, expected = rdb.cksum;
+
+        if (rioRead(&rdb,&cksum,8) == 0) goto eoferr;
+        memrev64ifbe(&cksum);
+        if (cksum == 0) {
+            redisLog(REDIS_WARNING,"RDB file was saved with checksum disabled: no check performed.");
+        } else if (cksum != expected) {
+            redisLog(REDIS_WARNING,"Wrong RDB checksum. Aborting now.");
+            exit(1);
+        }
+    }
+
     fclose(fp);
     stopLoading();
     return REDIS_OK;
@@ -1124,6 +1157,8 @@ void backgroundSaveDoneHandler(int exitcode, int bysignal) {
         server.lastbgsave_status = REDIS_ERR;
     }
     server.rdb_child_pid = -1;
+    server.rdb_save_time_last = time(NULL)-server.rdb_save_time_start;
+    server.rdb_save_time_start = -1;
     /* Possibly there are slaves waiting for a BGSAVE in order to be served
      * (the first stage of SYNC is a bulk transfer of dump.rdb) */
     updateSlavesWaitingBgsave(exitcode == 0 ? REDIS_OK : REDIS_ERR);