Resp3 verbatim string support (#805)

Pull RESP3 verbatim string handling from Redis Fixes #802
redis · May 19, 2020 · 5c9f49e · 5c9f49e
1 parent 243099c
commit 5c9f49e
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Showing 5 changed files with 52 additions and 13 deletions.
diff --git a/hiredis.c b/hiredis.c
@@ -107,6 +107,7 @@ void freeReplyObject(void *reply) {
     case REDIS_REPLY_STATUS:
     case REDIS_REPLY_STRING:
     case REDIS_REPLY_DOUBLE:
+    case REDIS_REPLY_VERB:
         free(r->str);
         break;
     }
@@ -121,21 +122,34 @@ static void *createStringObject(const redisReadTask *task, char *str, size_t len
     if (r == NULL)
         return NULL;
 
-    buf = malloc(len+1);
-    if (buf == NULL) {
-        freeReplyObject(r);
-        return NULL;
-    }
-
     assert(task->type == REDIS_REPLY_ERROR  ||
            task->type == REDIS_REPLY_STATUS ||
-           task->type == REDIS_REPLY_STRING);
+           task->type == REDIS_REPLY_STRING ||
+           task->type == REDIS_REPLY_VERB);
 
     /* Copy string value */
-    memcpy(buf,str,len);
-    buf[len] = '\0';
+    if (task->type == REDIS_REPLY_VERB) {
+        buf = malloc(len-4+1); /* Skip 4 bytes of verbatim type header. */
+        if (buf == NULL) {
+            freeReplyObject(r);
+            return NULL;
+        }
+        memcpy(r->vtype,str,3);
+        r->vtype[3] = '\0';
+        memcpy(buf,str+4,len-4);
+        buf[len-4] = '\0';
+        r->len = len - 4;
+    } else {
+        buf = malloc(len+1);
+        if (buf == NULL) {
+            freeReplyObject(r);
+            return NULL;
+        }
+        memcpy(buf,str,len);
+        buf[len] = '\0';
+        r->len = len;
+    }
     r->str = buf;
-    r->len = len;
 
     if (task->parent) {
         parent = task->parent->obj;

diff --git a/hiredis.h b/hiredis.h
@@ -102,7 +102,9 @@ typedef struct redisReply {
     double dval; /* The double when type is REDIS_REPLY_DOUBLE */
     size_t len; /* Length of string */
     char *str; /* Used for REDIS_REPLY_ERROR, REDIS_REPLY_STRING
-                  and REDIS_REPLY_DOUBLE (in additional to dval). */
+                  REDIS_REPLY_VERB, and REDIS_REPLY_DOUBLE (in additional to dval). */
+    char vtype[4]; /* Used for REDIS_REPLY_VERB, contains the null
+                      terminated 3 character content type, such as "txt". */
     size_t elements; /* number of elements, for REDIS_REPLY_ARRAY */
     struct redisReply **element; /* elements vector for REDIS_REPLY_ARRAY */
 } redisReply;

diff --git a/read.c b/read.c
@@ -383,10 +383,18 @@ static int processBulkItem(redisReader *r) {
             /* Only continue when the buffer contains the entire bulk item. */
             bytelen += len+2; /* include \r\n */
             if (r->pos+bytelen <= r->len) {
+                if ((cur->type == REDIS_REPLY_VERB && len < 4) ||
+                    (cur->type == REDIS_REPLY_VERB && s[5] != ':'))
+                {
+                    __redisReaderSetError(r,REDIS_ERR_PROTOCOL,
+                            "Verbatim string 4 bytes of content type are "
+                            "missing or incorrectly encoded.");
+                    return REDIS_ERR;
+                }
                 if (r->fn && r->fn->createString)
                     obj = r->fn->createString(cur,s+2,len);
                 else
-                    obj = (void*)REDIS_REPLY_STRING;
+                    obj = (void*)(long)cur->type;
                 success = 1;
             }
         }
@@ -551,6 +559,9 @@ static int processItem(redisReader *r) {
             case '#':
                 cur->type = REDIS_REPLY_BOOL;
                 break;
+            case '=':
+                cur->type = REDIS_REPLY_VERB;
+                break;
             default:
                 __redisReaderSetErrorProtocolByte(r,*p);
                 return REDIS_ERR;
@@ -571,6 +582,7 @@ static int processItem(redisReader *r) {
     case REDIS_REPLY_BOOL:
         return processLineItem(r);
     case REDIS_REPLY_STRING:
+    case REDIS_REPLY_VERB:
         return processBulkItem(r);
     case REDIS_REPLY_ARRAY:
     case REDIS_REPLY_MAP:

diff --git a/read.h b/read.h
@@ -56,12 +56,12 @@
 #define REDIS_REPLY_ERROR 6
 #define REDIS_REPLY_DOUBLE 7
 #define REDIS_REPLY_BOOL 8
-#define REDIS_REPLY_VERB 9
 #define REDIS_REPLY_MAP 9
 #define REDIS_REPLY_SET 10
 #define REDIS_REPLY_ATTR 11
 #define REDIS_REPLY_PUSH 12
 #define REDIS_REPLY_BIGNUM 13
+#define REDIS_REPLY_VERB 14
 
 #define REDIS_READER_MAX_BUF (1024*16)  /* Default max unused reader buffer. */
 

diff --git a/test.c b/test.c
@@ -477,6 +477,17 @@ static void test_reply_reader(void) {
         ((redisReply*)reply)->elements == 0);
     freeReplyObject(reply);
     redisReaderFree(reader);
+
+    /* RESP3 verbatim strings (GitHub issue #802) */
+    test("Can parse RESP3 verbatim strings: ");
+    reader = redisReaderCreate();
+    redisReaderFeed(reader,(char*)"=10\r\ntxt:LOLWUT\r\n",17);
+    ret = redisReaderGetReply(reader,&reply);
+    test_cond(ret == REDIS_OK &&
+        ((redisReply*)reply)->type == REDIS_REPLY_VERB &&
+         !memcmp(((redisReply*)reply)->str,"LOLWUT", 6));
+    freeReplyObject(reply);
+    redisReaderFree(reader);
 }
 
 static void test_free_null(void) {