Allow users to replace allocator and handle OOM everywhere. (#800)

* Adds an indirection to every allocation/deallocation to allow users to 
  plug in ones of their choosing (use custom functions, jemalloc, etc).

* Gracefully handle OOM everywhere in hiredis.  This should make it possible
  for users of the library to have more flexibility in how they handle such situations.

* Changes `redisReaderTask->elements` from an `int` to a `long long` to prevent
  a possible overflow when transferring the task elements into a `redisReply`.

* Adds a configurable `max elements` member to `redisReader` that defaults to
  2^32 - 1.  This can be set to "unlimited" by setting the value to zero.

23 files changed, 471 insertions, 196 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7844575..87a4ac6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,14 +24,14 @@ PROJECT(hiredis VERSION "${VERSION}")
 SET(ENABLE_EXAMPLES OFF CACHE BOOL "Enable building hiredis examples")
 
 SET(hiredis_sources
+    alloc.c
     async.c
     dict.c
     hiredis.c
     net.c
     read.c
     sds.c
-    sockcompat.c
-    alloc.c)
+    sockcompat.c)
 
 SET(hiredis_sources ${hiredis_sources})
 
diff --git a/Makefile b/Makefile
index 438ab8f..f19e760 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 # Copyright (C) 2010-2011 Pieter Noordhuis <pcnoordhuis at gmail dot com>
 # This file is released under the BSD license, see the COPYING file
 
-OBJ=net.o hiredis.o sds.o async.o read.o sockcompat.o alloc.o
+OBJ=alloc.o net.o hiredis.o sds.o async.o read.o sockcompat.o
 SSL_OBJ=ssl.o
 EXAMPLES=hiredis-example hiredis-example-libevent hiredis-example-libev hiredis-example-glib
 ifeq ($(USE_SSL),1)
@@ -109,16 +109,16 @@ all: $(SSL_DYLIBNAME) $(SSL_STLIBNAME) $(SSL_PKGCONFNAME)
 endif
 
 # Deps (use make dep to generate this)
+alloc.o: alloc.c fmacros.h alloc.h
 async.o: async.c fmacros.h alloc.h async.h hiredis.h read.h sds.h net.h dict.c dict.h win32.h async_private.h
 dict.o: dict.c fmacros.h alloc.h dict.h
 hiredis.o: hiredis.c fmacros.h hiredis.h read.h sds.h alloc.h net.h async.h win32.h
-alloc.o: alloc.c alloc.h
 net.o: net.c fmacros.h net.h hiredis.h read.h sds.h alloc.h sockcompat.h win32.h
-read.o: read.c fmacros.h read.h sds.h win32.h
-sds.o: sds.c sds.h sdsalloc.h
+read.o: read.c fmacros.h alloc.h read.h sds.h win32.h
+sds.o: sds.c sds.h sdsalloc.h alloc.h
 sockcompat.o: sockcompat.c sockcompat.h
-ssl.o: ssl.c hiredis.h read.h sds.h alloc.h async.h async_private.h
-test.o: test.c fmacros.h hiredis.h read.h sds.h alloc.h net.h
+ssl.o: ssl.c hiredis.h read.h sds.h alloc.h async.h win32.h async_private.h
+test.o: test.c fmacros.h hiredis.h read.h sds.h alloc.h net.h sockcompat.h win32.h
 
 $(DYLIBNAME): $(OBJ)
 	$(DYLIB_MAKE_CMD) -o $(DYLIBNAME) $(OBJ) $(REAL_LDFLAGS)
diff --git a/README.md b/README.md
index a979110..4e7b228 100644
--- a/README.md
+++ b/README.md
@@ -404,6 +404,16 @@ This should be done only in order to maximize performances when working with
 large payloads. The context should be set back to `REDIS_READER_MAX_BUF` again
 as soon as possible in order to prevent allocation of useless memory.
 
+### Reader max array elements
+
+By default the hiredis reply parser sets the maximum number of multi-bulk elements
+to 2^32 - 1 or 4,294,967,295 entries.  If you need to process multi-bulk replies
+with more than this many elements you can set the value higher or to zero, meaning
+unlimited with:
+```c
+context->reader->maxelements = 0;
+```
+
 ## SSL/TLS Support
 
 ### Building
diff --git a/adapters/ae.h b/adapters/ae.h
index 0393992..660d82e 100644
--- a/adapters/ae.h
+++ b/adapters/ae.h
@@ -96,7 +96,7 @@ static void redisAeCleanup(void *privdata) {
     redisAeEvents *e = (redisAeEvents*)privdata;
     redisAeDelRead(privdata);
     redisAeDelWrite(privdata);
-    free(e);
+    hi_free(e);
 }
 
 static int redisAeAttach(aeEventLoop *loop, redisAsyncContext *ac) {
@@ -109,6 +109,9 @@ static int redisAeAttach(aeEventLoop *loop, redisAsyncContext *ac) {
 
     /* Create container for context and r/w events */
     e = (redisAeEvents*)hi_malloc(sizeof(*e));
+    if (e == NULL)
+        return REDIS_ERR;
+
     e->context = ac;
     e->loop = loop;
     e->fd = c->fd;
diff --git a/adapters/glib.h b/adapters/glib.h
index e0a6411..ad59dd1 100644
--- a/adapters/glib.h
+++ b/adapters/glib.h
@@ -134,6 +134,9 @@ redis_source_new (redisAsyncContext *ac)
     g_return_val_if_fail(ac != NULL, NULL);
 
     source = (RedisSource *)g_source_new(&source_funcs, sizeof *source);
+    if (source == NULL)
+        return NULL;
+
     source->ac = ac;
     source->poll_fd.fd = c->fd;
     source->poll_fd.events = 0;
diff --git a/adapters/ivykis.h b/adapters/ivykis.h
index 75616ee..179f6ab 100644
--- a/adapters/ivykis.h
+++ b/adapters/ivykis.h
@@ -43,7 +43,7 @@ static void redisIvykisCleanup(void *privdata) {
     redisIvykisEvents *e = (redisIvykisEvents*)privdata;
 
     iv_fd_unregister(&e->fd);
-    free(e);
+    hi_free(e);
 }
 
 static int redisIvykisAttach(redisAsyncContext *ac) {
@@ -56,6 +56,9 @@ static int redisIvykisAttach(redisAsyncContext *ac) {
 
     /* Create container for context and r/w events */
     e = (redisIvykisEvents*)hi_malloc(sizeof(*e));
+    if (e == NULL)
+        return REDIS_ERR;
+
     e->context = ac;
 
     /* Register functions to start/stop listening for events */
diff --git a/adapters/libev.h b/adapters/libev.h
index 1520923..7057dbd 100644
--- a/adapters/libev.h
+++ b/adapters/libev.h
@@ -116,7 +116,7 @@ static void redisLibevCleanup(void *privdata) {
     redisLibevDelRead(privdata);
     redisLibevDelWrite(privdata);
     redisLibevStopTimer(privdata);
-    free(e);
+    hi_free(e);
 }
 
 static void redisLibevTimeout(EV_P_ ev_timer *timer, int revents) {
@@ -149,6 +149,9 @@ static int redisLibevAttach(EV_P_ redisAsyncContext *ac) {
 
     /* Create container for context and r/w events */
     e = (redisLibevEvents*)hi_calloc(1, sizeof(*e));
+    if (e == NULL)
+        return REDIS_ERR;
+
     e->context = ac;
 #if EV_MULTIPLICITY
     e->loop = loop;
diff --git a/adapters/libevent.h b/adapters/libevent.h
index 0674ca6..9150979 100644
--- a/adapters/libevent.h
+++ b/adapters/libevent.h
@@ -47,7 +47,7 @@ typedef struct redisLibeventEvents {
 } redisLibeventEvents;
 
 static void redisLibeventDestroy(redisLibeventEvents *e) {
-    free(e);
+    hi_free(e);
 }
 
 static void redisLibeventHandler(int fd, short event, void *arg) {
@@ -153,6 +153,9 @@ static int redisLibeventAttach(redisAsyncContext *ac, struct event_base *base) {
 
     /* Create container for context and r/w events */
     e = (redisLibeventEvents*)hi_calloc(1, sizeof(*e));
+    if (e == NULL)
+        return REDIS_ERR;
+
     e->context = ac;
 
     /* Register functions to start/stop listening for events */
diff --git a/adapters/libuv.h b/adapters/libuv.h
index 7aac127..c120b1b 100644
--- a/adapters/libuv.h
+++ b/adapters/libuv.h
@@ -73,7 +73,7 @@ static void redisLibuvDelWrite(void *privdata) {
 static void on_close(uv_handle_t* handle) {
   redisLibuvEvents* p = (redisLibuvEvents*)handle->data;
 
-  free(p);
+  hi_free(p);
 }
 
 
@@ -98,11 +98,9 @@ static int redisLibuvAttach(redisAsyncContext* ac, uv_loop_t* loop) {
   ac->ev.delWrite = redisLibuvDelWrite;
   ac->ev.cleanup  = redisLibuvCleanup;
 
-  redisLibuvEvents* p = (redisLibuvEvents*)malloc(sizeof(*p));
-
-  if (!p) {
-    return REDIS_ERR;
-  }
+  redisLibuvEvents* p = (redisLibuvEvents*)hi_malloc(sizeof(*p));
+  if (p == NULL)
+      return REDIS_ERR;
 
   memset(p, 0, sizeof(*p));
 
diff --git a/adapters/macosx.h b/adapters/macosx.h
index 72121f6..3c87f1b 100644
--- a/adapters/macosx.h
+++ b/adapters/macosx.h
@@ -27,7 +27,7 @@ static int freeRedisRunLoop(RedisRunLoop* redisRunLoop) {
             CFSocketInvalidate(redisRunLoop->socketRef);
             CFRelease(redisRunLoop->socketRef);
         }
-        free(redisRunLoop);
+        hi_free(redisRunLoop);
     }
     return REDIS_ERR;
 }
@@ -80,8 +80,9 @@ static int redisMacOSAttach(redisAsyncContext *redisAsyncCtx, CFRunLoopRef runLo
     /* Nothing should be attached when something is already attached */
     if( redisAsyncCtx->ev.data != NULL ) return REDIS_ERR;
 
-    RedisRunLoop* redisRunLoop = (RedisRunLoop*) calloc(1, sizeof(RedisRunLoop));
-    if( !redisRunLoop ) return REDIS_ERR;
+    RedisRunLoop* redisRunLoop = (RedisRunLoop*) hi_calloc(1, sizeof(RedisRunLoop));
+    if (redisRunLoop == NULL)
+        return REDIS_ERR;
 
     /* Setup redis stuff */
     redisRunLoop->context = redisAsyncCtx;
diff --git a/alloc.c b/alloc.c
index 55c3020..2b19c48 100644
--- a/alloc.c
+++ b/alloc.c
@@ -31,35 +31,56 @@
 #include "fmacros.h"
 #include "alloc.h"
 #include <string.h>
+#include <stdlib.h>
 
-void *hi_malloc(size_t size) {
-    void *ptr = malloc(size);
-    if (ptr == NULL)
-        HIREDIS_OOM_HANDLER;
+hiredisAllocFuncs hiredisAllocFns = {
+    .malloc = malloc,
+    .calloc = calloc,
+    .realloc = realloc,
+    .strdup = strdup,
+    .free = free,
+};
+
+/* Override hiredis' allocators with ones supplied by the user */
+hiredisAllocFuncs hiredisSetAllocators(hiredisAllocFuncs *override) {
+    hiredisAllocFuncs orig = hiredisAllocFns;
 
-    return ptr;
+    hiredisAllocFns = *override;
+
+    return orig;
 }
 
-void *hi_calloc(size_t nmemb, size_t size) {
-    void *ptr = calloc(nmemb, size);
-    if (ptr == NULL)
-        HIREDIS_OOM_HANDLER;
+/* Reset allocators to use libc defaults */
+void hiredisResetAllocators(void) {
+    hiredisAllocFns = (hiredisAllocFuncs) {
+        .malloc = malloc,
+        .calloc = calloc,
+        .realloc = realloc,
+        .strdup = strdup,
+        .free = free,
+    };
+}
+
+#ifdef _WIN32
 
-    return ptr;
+void *hi_malloc(size_t size) {
+    return hiredisAllocFns.malloc(size);
 }
 
-void *hi_realloc(void *ptr, size_t size) {
-    void *newptr = realloc(ptr, size);
-    if (newptr == NULL)
-        HIREDIS_OOM_HANDLER;
+void *hi_calloc(size_t nmemb, size_t size) {
+    return hiredisAllocFns.calloc(nmemb, size);
+}
 
-    return newptr;
+void *hi_realloc(void *ptr, size_t size) {
+    return hiredisAllocFns.realloc(ptr, size);
 }
 
 char *hi_strdup(const char *str) {
-    char *newstr = strdup(str);
-    if (newstr == NULL)
-        HIREDIS_OOM_HANDLER;
+    return hiredisAllocFns.strdup(str);
+}
 
-    return newstr;
+void hi_free(void *ptr) {
+    hiredisAllocFns.free(ptr);
 }
+
+#endif
diff --git a/alloc.h b/alloc.h
index 2c9b04e..b581e56 100644
--- a/alloc.h
+++ b/alloc.h
@@ -31,23 +31,61 @@
 #ifndef HIREDIS_ALLOC_H
 #define HIREDIS_ALLOC_H
 
-#include <stdlib.h> /* for size_t */
-
-#ifndef HIREDIS_OOM_HANDLER
-#define HIREDIS_OOM_HANDLER abort()
-#endif
+#include <stddef.h> /* for size_t */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/* Structure pointing to our actually configured allocators */
+typedef struct hiredisAllocFuncs {
+    void *(*malloc)(size_t);
+    void *(*calloc)(size_t,size_t);
+    void *(*realloc)(void*,size_t);
+    char *(*strdup)(const char*);
+    void (*free)(void*);
+} hiredisAllocFuncs;
+
+hiredisAllocFuncs hiredisSetAllocators(hiredisAllocFuncs *ha);
+void hiredisResetAllocators(void);
+
+#ifndef _WIN32
+
+/* Hiredis' configured allocator function pointer struct */
+extern hiredisAllocFuncs hiredisAllocFns;
+
+static inline void *hi_malloc(size_t size) {
+    return hiredisAllocFns.malloc(size);
+}
+
+static inline void *hi_calloc(size_t nmemb, size_t size) {
+    return hiredisAllocFns.calloc(nmemb, size);
+}
+
+static inline void *hi_realloc(void *ptr, size_t size) {
+    return hiredisAllocFns.realloc(ptr, size);
+}
+
+static inline char *hi_strdup(const char *str) {
+    return hiredisAllocFns.strdup(str);
+}
+
+static inline void hi_free(void *ptr) {
+    hiredisAllocFns.free(ptr);
+}
+
+#else
+
 void *hi_malloc(size_t size);
 void *hi_calloc(size_t nmemb, size_t size);
 void *hi_realloc(void *ptr, size_t size);
 char *hi_strdup(const char *str);
+void hi_free(void *ptr);
+
+#endif
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif  /* HIREDIS_ALLOC_H */
+#endif /* HIREDIS_ALLOC_H */
diff --git a/async.c b/async.c
index 68a656f..261fe24 100644
--- a/async.c
+++ b/async.c
@@ -47,8 +47,9 @@
 
 #include "async_private.h"
 
-/* Forward declaration of function in hiredis.c */
+/* Forward declarations of hiredis.c functions */
 int __redisAppendCommand(redisContext *c, const char *cmd, size_t len);
+void __redisSetError(redisContext *c, int type, const char *str);
 
 /* Functions managing dictionary of callbacks for pub/sub. */
 static unsigned int callbackHash(const void *key) {
@@ -58,7 +59,12 @@ static unsigned int callbackHash(const void *key) {
 
 static void *callbackValDup(void *privdata, const void *src) {
     ((void) privdata);
-    redisCallback *dup = hi_malloc(sizeof(*dup));
+    redisCallback *dup;
+
+    dup = hi_malloc(sizeof(*dup));
+    if (dup == NULL)
+        return NULL;
+
     memcpy(dup,src,sizeof(*dup));
     return dup;
 }
@@ -80,7 +86,7 @@ static void callbackKeyDestructor(void *privdata, void *key) {
 
 static void callbackValDestructor(void *privdata, void *val) {
     ((void) privdata);
-    free(val);
+    hi_free(val);
 }
 
 static dictType callbackDict = {
@@ -94,10 +100,19 @@ static dictType callbackDict = {
 
 static redisAsyncContext *redisAsyncInitialize(redisContext *c) {
     redisAsyncContext *ac;
+    dict *channels = NULL, *patterns = NULL;
+
+    channels = dictCreate(&callbackDict,NULL);
+    if (channels == NULL)
+        goto oom;
+
+    patterns = dictCreate(&callbackDict,NULL);
+    if (patterns == NULL)
+        goto oom;
 
-    ac = realloc(c,sizeof(redisAsyncContext));
+    ac = hi_realloc(c,sizeof(redisAsyncContext));
     if (ac == NULL)
-        return NULL;
+        goto oom;
 
     c = &(ac->c);
 
@@ -126,9 +141,14 @@ static redisAsyncContext *redisAsyncInitialize(redisContext *c) {
     ac->replies.tail = NULL;
     ac->sub.invalid.head = NULL;
     ac->sub.invalid.tail = NULL;
-    ac->sub.channels = dictCreate(&callbackDict,NULL);
-    ac->sub.patterns = dictCreate(&callbackDict,NULL);
+    ac->sub.channels = channels;
+    ac->sub.patterns = patterns;
+
     return ac;
+oom:
+    if (channels) dictRelease(channels);
+    if (patterns) dictRelease(patterns);
+    return NULL;
 }
 
 /* We want the error field to be accessible directly instead of requiring
@@ -216,7 +236,7 @@ static int __redisPushCallback(redisCallbackList *list, redisCallback *source) {
     redisCallback *cb;
 
     /* Copy callback from stack to heap */
-    cb = malloc(sizeof(*cb));
+    cb = hi_malloc(sizeof(*cb));
     if (cb == NULL)
         return REDIS_ERR_OOM;
 
@@ -244,7 +264,7 @@ static int __redisShiftCallback(redisCallbackList *list, redisCallback *target)
         /* Copy callback from heap to stack */
         if (target != NULL)
             memcpy(target,cb,sizeof(*cb));
-        free(cb);
+        hi_free(cb);
         return REDIS_OK;
     }
     return REDIS_ERR;
@@ -275,17 +295,27 @@ static void __redisAsyncFree(redisAsyncContext *ac) {
         __redisRunCallback(ac,&cb,NULL);
 
     /* Run subscription callbacks callbacks with NULL reply */
-    it = dictGetIterator(ac->sub.channels);
-    while ((de = dictNext(it)) != NULL)
-        __redisRunCallback(ac,dictGetEntryVal(de),NULL);
-    dictReleaseIterator(it);
-    dictRelease(ac->sub.channels);
-
-    it = dictGetIterator(ac->sub.patterns);
-    while ((de = dictNext(it)) != NULL)
-        __redisRunCallback(ac,dictGetEntryVal(de),NULL);
-    dictReleaseIterator(it);
-    dictRelease(ac->sub.patterns);
+    if (ac->sub.channels) {
+        it = dictGetIterator(ac->sub.channels);
+        if (it != NULL) {
+            while ((de = dictNext(it)) != NULL)
+                __redisRunCallback(ac,dictGetEntryVal(de),NULL);
+            dictReleaseIterator(it);
+        }
+
+        dictRelease(ac->sub.channels);
+    }
+
+    if (ac->sub.patterns) {
+        it = dictGetIterator(ac->sub.patterns);
+        if (it != NULL) {
+            while ((de = dictNext(it)) != NULL)
+                __redisRunCallback(ac,dictGetEntryVal(de),NULL);
+            dictReleaseIterator(it);
+        }
+
+        dictRelease(ac->sub.patterns);
+    }
 
     /* Signal event lib to clean up */
     _EL_CLEANUP(ac);
@@ -388,6 +418,9 @@ static int __redisGetSubscribeCallback(redisAsyncContext *ac, redisReply *reply,
         /* Locate the right callback */
         assert(reply->element[1]->type == REDIS_REPLY_STRING);
         sname = sdsnewlen(reply->element[1]->str,reply->element[1]->len);
+        if (sname == NULL)
+            goto oom;
+
         de = dictFind(callbacks,sname);
         if (de != NULL) {
             cb = dictGetEntryVal(de);
@@ -421,6 +454,9 @@ static int __redisGetSubscribeCallback(redisAsyncContext *ac, redisReply *reply,
         __redisShiftCallback(&ac->sub.invalid,dstcb);
     }
     return REDIS_OK;
+oom:
+    __redisSetError(&(ac->c), REDIS_ERR_OOM, "Out of memory");
+    return REDIS_ERR;
 }
 
 void redisProcessCallbacks(redisAsyncContext *ac) {
@@ -588,8 +624,6 @@ void redisAsyncHandleWrite(redisAsyncContext *ac) {
     c->funcs->async_write(ac);
 }
 
-void __redisSetError(redisContext *c, int type, const char *str);
-
 void redisAsyncHandleTimeout(redisAsyncContext *ac) {
     redisContext *c = &(ac->c);
     redisCallback cb;
@@ -672,6 +706,9 @@ static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void
         /* Add every channel/pattern to the list of subscription callbacks. */
         while ((p = nextArgument(p,&astr,&alen)) != NULL) {
             sname = sdsnewlen(astr,alen);
+            if (sname == NULL)
+                goto oom;
+
             if (pvariant)
                 cbdict = ac->sub.patterns;
             else
@@ -715,6 +752,9 @@ static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void
     _EL_ADD_WRITE(ac);
 
     return REDIS_OK;
+oom:
+    __redisSetError(&(ac->c), REDIS_ERR_OOM, "Out of memory");
+    return REDIS_ERR;
 }
 
 int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, va_list ap) {
@@ -728,7 +768,7 @@ int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdat
         return REDIS_ERR;
 
     status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
-    free(cmd);
+    hi_free(cmd);
     return status;
 }
 
@@ -758,15 +798,21 @@ int redisAsyncFormattedCommand(redisAsyncContext *ac, redisCallbackFn *fn, void
     return status;
 }
 
-void redisAsyncSetTimeout(redisAsyncContext *ac, struct timeval tv) {
+int redisAsyncSetTimeout(redisAsyncContext *ac, struct timeval tv) {
     if (!ac->c.timeout) {
         ac->c.timeout = hi_calloc(1, sizeof(tv));
+        if (ac->c.timeout == NULL) {
+            __redisSetError(&ac->c, REDIS_ERR_OOM, "Out of memory");
+            __redisAsyncCopyError(ac);
+            return REDIS_ERR;
+        }
     }
 
-    if (tv.tv_sec == ac->c.timeout->tv_sec &&
-        tv.tv_usec == ac->c.timeout->tv_usec) {
-        return;
+    if (tv.tv_sec != ac->c.timeout->tv_sec ||
+        tv.tv_usec != ac->c.timeout->tv_usec)
+    {
+        *ac->c.timeout = tv;
     }
 
-    *ac->c.timeout = tv;
+    return REDIS_OK;
 }
diff --git a/async.h b/async.h
index 781f1d1..ba301da 100644
--- a/async.h
+++ b/async.h
@@ -118,7 +118,7 @@ redisAsyncContext *redisAsyncConnectUnix(const char *path);
 int redisAsyncSetConnectCallback(redisAsyncContext *ac, redisConnectCallback *fn);
 int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn);
 
-void redisAsyncSetTimeout(redisAsyncContext *ac, struct timeval tv);
+int redisAsyncSetTimeout(redisAsyncContext *ac, struct timeval tv);
 void redisAsyncDisconnect(redisAsyncContext *ac);
 void redisAsyncFree(redisAsyncContext *ac);
 
diff --git a/dict.c b/dict.c
index eaf4e4d..34a33ea 100644
--- a/dict.c
+++ b/dict.c
@@ -73,6 +73,9 @@ static void _dictReset(dict *ht) {
 /* Create a new hash table */
 static dict *dictCreate(dictType *type, void *privDataPtr) {
     dict *ht = hi_malloc(sizeof(*ht));
+    if (ht == NULL)
+        return NULL;
+
     _dictInit(ht,type,privDataPtr);
     return ht;
 }
@@ -98,7 +101,9 @@ static int dictExpand(dict *ht, unsigned long size) {
     _dictInit(&n, ht->type, ht->privdata);
     n.size = realsize;
     n.sizemask = realsize-1;
-    n.table = calloc(realsize,sizeof(dictEntry*));
+    n.table = hi_calloc(realsize,sizeof(dictEntry*));
+    if (n.table == NULL)
+        return DICT_ERR;
 
     /* Copy all the elements from the old to the new table:
      * note that if the old hash table is empty ht->size is zero,
@@ -125,7 +130,7 @@ static int dictExpand(dict *ht, unsigned long size) {
         }
     }
     assert(ht->used == 0);
-    free(ht->table);
+    hi_free(ht->table);
 
     /* Remap the new hashtable in the old */
     *ht = n;
@@ -144,6 +149,9 @@ static int dictAdd(dict *ht, void *key, void *val) {
 
     /* Allocates the memory and stores key */
     entry = hi_malloc(sizeof(*entry));
+    if (entry == NULL)
+        return DICT_ERR;
+
     entry->next = ht->table[index];
     ht->table[index] = entry;
 
@@ -167,6 +175,9 @@ static int dictReplace(dict *ht, void *key, void *val) {
         return 1;
     /* It already exists, get the entry */
     entry = dictFind(ht, key);
+    if (entry == NULL)
+        return 0;
+
     /* Free the old value and set the new one */
     /* Set the new value and free the old one. Note that it is important
      * to do that in this order, as the value may just be exactly the same
@@ -200,7 +211,7 @@ static int dictDelete(dict *ht, const void *key) {
 
             dictFreeEntryKey(ht,de);
             dictFreeEntryVal(ht,de);
-            free(de);
+            hi_free(de);
             ht->used--;
             return DICT_OK;
         }
@@ -223,13 +234,13 @@ static int _dictClear(dict *ht) {
             nextHe = he->next;
             dictFreeEntryKey(ht, he);
             dictFreeEntryVal(ht, he);
-            free(he);
+            hi_free(he);
             ht->used--;
             he = nextHe;
         }
     }
     /* Free the table and the allocated cache structure */
-    free(ht->table);
+    hi_free(ht->table);
     /* Re-initialize the table */
     _dictReset(ht);
     return DICT_OK; /* never fails */
@@ -238,7 +249,7 @@ static int _dictClear(dict *ht) {
 /* Clear & Release the hash table */
 static void dictRelease(dict *ht) {
     _dictClear(ht);
-    free(ht);
+    hi_free(ht);
 }
 
 static dictEntry *dictFind(dict *ht, const void *key) {
@@ -258,6 +269,8 @@ static dictEntry *dictFind(dict *ht, const void *key) {
 
 static dictIterator *dictGetIterator(dict *ht) {
     dictIterator *iter = hi_malloc(sizeof(*iter));
+    if (iter == NULL)
+        return NULL;
 
     iter->ht = ht;
     iter->index = -1;
@@ -287,7 +300,7 @@ static dictEntry *dictNext(dictIterator *iter) {
 }
 
 static void dictReleaseIterator(dictIterator *iter) {
-    free(iter);
+    hi_free(iter);
 }
 
 /* ------------------------- private functions ------------------------------ */
diff --git a/hiredis.c b/hiredis.c
index 1c9e8ae..3133716 100644
--- a/hiredis.c
+++ b/hiredis.c
@@ -74,7 +74,7 @@ static redisReplyObjectFunctions defaultFunctions = {
 
 /* Create a reply object */
 static redisReply *createReplyObject(int type) {
-    redisReply *r = calloc(1,sizeof(*r));
+    redisReply *r = hi_calloc(1,sizeof(*r));
 
     if (r == NULL)
         return NULL;
@@ -101,7 +101,7 @@ void freeReplyObject(void *reply) {
         if (r->element != NULL) {
             for (j = 0; j < r->elements; j++)
                 freeReplyObject(r->element[j]);
-            free(r->element);
+            hi_free(r->element);
         }
         break;
     case REDIS_REPLY_ERROR:
@@ -109,10 +109,10 @@ void freeReplyObject(void *reply) {
     case REDIS_REPLY_STRING:
     case REDIS_REPLY_DOUBLE:
     case REDIS_REPLY_VERB:
-        free(r->str);
+        hi_free(r->str);
         break;
     }
-    free(r);
+    hi_free(r);
 }
 
 static void *createStringObject(const redisReadTask *task, char *str, size_t len) {
@@ -130,22 +130,18 @@ static void *createStringObject(const redisReadTask *task, char *str, size_t len
 
     /* Copy string value */
     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;
-        }
+        buf = hi_malloc(len-4+1); /* Skip 4 bytes of verbatim type header. */
+        if (buf == NULL) goto oom;
+
         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;
-        }
+        buf = hi_malloc(len+1);
+        if (buf == NULL) goto oom;
+
         memcpy(buf,str,len);
         buf[len] = '\0';
         r->len = len;
@@ -161,6 +157,10 @@ static void *createStringObject(const redisReadTask *task, char *str, size_t len
         parent->element[task->idx] = r;
     }
     return r;
+
+oom:
+    freeReplyObject(r);
+    return NULL;
 }
 
 static void *createArrayObject(const redisReadTask *task, size_t elements) {
@@ -171,7 +171,7 @@ static void *createArrayObject(const redisReadTask *task, size_t elements) {
         return NULL;
 
     if (elements > 0) {
-        r->element = calloc(elements,sizeof(redisReply*));
+        r->element = hi_calloc(elements,sizeof(redisReply*));
         if (r->element == NULL) {
             freeReplyObject(r);
             return NULL;
@@ -218,7 +218,7 @@ static void *createDoubleObject(const redisReadTask *task, double value, char *s
         return NULL;
 
     r->dval = value;
-    r->str = malloc(len+1);
+    r->str = hi_malloc(len+1);
     if (r->str == NULL) {
         freeReplyObject(r);
         return NULL;
@@ -322,7 +322,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
         if (*c != '%' || c[1] == '\0') {
             if (*c == ' ') {
                 if (touched) {
-                    newargv = realloc(curargv,sizeof(char*)*(argc+1));
+                    newargv = hi_realloc(curargv,sizeof(char*)*(argc+1));
                     if (newargv == NULL) goto memory_err;
                     curargv = newargv;
                     curargv[argc++] = curarg;
@@ -471,7 +471,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
 
     /* Add the last argument if needed */
     if (touched) {
-        newargv = realloc(curargv,sizeof(char*)*(argc+1));
+        newargv = hi_realloc(curargv,sizeof(char*)*(argc+1));
         if (newargv == NULL) goto memory_err;
         curargv = newargv;
         curargv[argc++] = curarg;
@@ -487,7 +487,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
     totlen += 1+countDigits(argc)+2;
 
     /* Build the command at protocol level */
-    cmd = malloc(totlen+1);
+    cmd = hi_malloc(totlen+1);
     if (cmd == NULL) goto memory_err;
 
     pos = sprintf(cmd,"*%d\r\n",argc);
@@ -502,7 +502,7 @@ int redisvFormatCommand(char **target, const char *format, va_list ap) {
     assert(pos == totlen);
     cmd[pos] = '\0';
 
-    free(curargv);
+    hi_free(curargv);
     *target = cmd;
     return totlen;
 
@@ -518,11 +518,11 @@ cleanup:
     if (curargv) {
         while(argc--)
             sdsfree(curargv[argc]);
-        free(curargv);
+        hi_free(curargv);
     }
 
     sdsfree(curarg);
-    free(cmd);
+    hi_free(cmd);
 
     return error_type;
 }
@@ -563,7 +563,7 @@ int redisFormatCommand(char **target, const char *format, ...) {
 int redisFormatSdsCommandArgv(sds *target, int argc, const char **argv,
                               const size_t *argvlen)
 {
-    sds cmd;
+    sds cmd, aux;
     unsigned long long totlen;
     int j;
     size_t len;
@@ -585,9 +585,13 @@ int redisFormatSdsCommandArgv(sds *target, int argc, const char **argv,
         return -1;
 
     /* We already know how much storage we need */
-    cmd = sdsMakeRoomFor(cmd, totlen);
-    if (cmd == NULL)
+    aux = sdsMakeRoomFor(cmd, totlen);
+    if (aux == NULL) {
+        sdsfree(cmd);
         return -1;
+    }
+
+    cmd = aux;
 
     /* Construct command */
     cmd = sdscatfmt(cmd, "*%i\r\n", argc);
@@ -631,7 +635,7 @@ int redisFormatCommandArgv(char **target, int argc, const char **argv, const siz
     }
 
     /* Build the command at protocol level */
-    cmd = malloc(totlen+1);
+    cmd = hi_malloc(totlen+1);
     if (cmd == NULL)
         return -1;
 
@@ -652,7 +656,7 @@ int redisFormatCommandArgv(char **target, int argc, const char **argv, const siz
 }
 
 void redisFreeCommand(char *cmd) {
-    free(cmd);
+    hi_free(cmd);
 }
 
 void __redisSetError(redisContext *c, int type, const char *str) {
@@ -678,7 +682,7 @@ redisReader *redisReaderCreate(void) {
 static redisContext *redisContextInit(const redisOptions *options) {
     redisContext *c;
 
-    c = calloc(1, sizeof(*c));
+    c = hi_calloc(1, sizeof(*c));
     if (c == NULL)
         return NULL;
 
@@ -702,16 +706,16 @@ void redisFree(redisContext *c) {
 
     sdsfree(c->obuf);
     redisReaderFree(c->reader);
-    free(c->tcp.host);
-    free(c->tcp.source_addr);
-    free(c->unix_sock.path);
-    free(c->timeout);
-    free(c->saddr);
+    hi_free(c->tcp.host);
+    hi_free(c->tcp.source_addr);
+    hi_free(c->unix_sock.path);
+    hi_free(c->timeout);
+    hi_free(c->saddr);
     if (c->funcs->free_privdata) {
         c->funcs->free_privdata(c->privdata);
     }
     memset(c, 0xff, sizeof(*c));
-    free(c);
+    hi_free(c);
 }
 
 redisFD redisFreeKeepFd(redisContext *c) {
@@ -738,6 +742,11 @@ int redisReconnect(redisContext *c) {
     c->obuf = sdsempty();
     c->reader = redisReaderCreate();
 
+    if (c->obuf == NULL || c->reader == NULL) {
+        __redisSetError(c, REDIS_ERR_OOM, "Out of memory");
+        return REDIS_ERR;
+    }
+
     if (c->connection_type == REDIS_CONN_TCP) {
         return redisContextConnectBindTcp(c, c->tcp.host, c->tcp.port,
                 c->timeout, c->tcp.source_addr);
@@ -918,6 +927,8 @@ int redisBufferWrite(redisContext *c, int *done) {
             if (nwritten == (signed)sdslen(c->obuf)) {
                 sdsfree(c->obuf);
                 c->obuf = sdsempty();
+                if (c->obuf == NULL)
+                    goto oom;
             } else {
                 sdsrange(c->obuf,nwritten,-1);
             }
@@ -925,6 +936,10 @@ int redisBufferWrite(redisContext *c, int *done) {
     }
     if (done != NULL) *done = (sdslen(c->obuf) == 0);
     return REDIS_OK;
+
+oom:
+    __redisSetError(c, REDIS_ERR_OOM, "Out of memory");
+    return REDIS_ERR;
 }
 
 /* Internal helper function to try and get a reply from the reader,
@@ -1015,11 +1030,11 @@ int redisvAppendCommand(redisContext *c, const char *format, va_list ap) {
     }
 
     if (__redisAppendCommand(c,cmd,len) != REDIS_OK) {
-        free(cmd);
+        hi_free(cmd);
         return REDIS_ERR;
     }
 
-    free(cmd);
+    hi_free(cmd);
     return REDIS_OK;
 }
 
diff --git a/net.c b/net.c
index bdb8943..54d904d 100644
--- a/net.c
+++ b/net.c
@@ -328,6 +328,22 @@ int redisContextSetTimeout(redisContext *c, const struct timeval tv) {
     return REDIS_OK;
 }
 
+static int _redisContextUpdateTimeout(redisContext *c, const struct timeval *timeout) {
+    /* Same timeval struct, short circuit */
+    if (c->timeout == timeout)
+        return REDIS_OK;
+
+    /* Allocate context timeval if we need to */
+    if (c->timeout == NULL) {
+        c->timeout = hi_malloc(sizeof(*c->timeout));
+        if (c->timeout == NULL)
+            return REDIS_ERR;
+    }
+
+    memcpy(c->timeout, timeout, sizeof(*c->timeout));
+    return REDIS_OK;
+}
+
 static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
                                    const struct timeval *timeout,
                                    const char *source_addr) {
@@ -352,20 +368,18 @@ static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
      * This is a bit ugly, but atleast it works and doesn't leak memory.
      **/
     if (c->tcp.host != addr) {
-        free(c->tcp.host);
+        hi_free(c->tcp.host);
 
         c->tcp.host = hi_strdup(addr);
+        if (c->tcp.host == NULL)
+            goto oom;
     }
 
     if (timeout) {
-        if (c->timeout != timeout) {
-            if (c->timeout == NULL)
-                c->timeout = hi_malloc(sizeof(struct timeval));
-
-            memcpy(c->timeout, timeout, sizeof(struct timeval));
-        }
+        if (_redisContextUpdateTimeout(c, timeout) == REDIS_ERR)
+            goto oom;
     } else {
-        free(c->timeout);
+        hi_free(c->timeout);
         c->timeout = NULL;
     }
 
@@ -375,10 +389,10 @@ static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
     }
 
     if (source_addr == NULL) {
-        free(c->tcp.source_addr);
+        hi_free(c->tcp.source_addr);
         c->tcp.source_addr = NULL;
     } else if (c->tcp.source_addr != source_addr) {
-        free(c->tcp.source_addr);
+        hi_free(c->tcp.source_addr);
         c->tcp.source_addr = hi_strdup(source_addr);
     }
 
@@ -442,8 +456,11 @@ addrretry:
         }
 
         /* For repeat connection */
-        free(c->saddr);
+        hi_free(c->saddr);
         c->saddr = hi_malloc(p->ai_addrlen);
+        if (c->saddr == NULL)
+            goto oom;
+
         memcpy(c->saddr, p->ai_addr, p->ai_addrlen);
         c->addrlen = p->ai_addrlen;
 
@@ -488,6 +505,8 @@ addrretry:
         goto error;
     }
 
+oom:
+    __redisSetError(c, REDIS_ERR_OOM, "Out of memory");
 error:
     rv = REDIS_ERR;
 end:
@@ -521,25 +540,32 @@ int redisContextConnectUnix(redisContext *c, const char *path, const struct time
         return REDIS_ERR;
 
     c->connection_type = REDIS_CONN_UNIX;
-    if (c->unix_sock.path != path)
+    if (c->unix_sock.path != path) {
+        hi_free(c->unix_sock.path);
+
         c->unix_sock.path = hi_strdup(path);
+        if (c->unix_sock.path == NULL)
+            goto oom;
+    }
 
     if (timeout) {
-        if (c->timeout != timeout) {
-            if (c->timeout == NULL)
-                c->timeout = hi_malloc(sizeof(struct timeval));
-
-            memcpy(c->timeout, timeout, sizeof(struct timeval));
-        }
+        if (_redisContextUpdateTimeout(c, timeout) == REDIS_ERR)
+            goto oom;
     } else {
-        free(c->timeout);
+        hi_free(c->timeout);
         c->timeout = NULL;
     }
 
     if (redisContextTimeoutMsec(c,&timeout_msec) != REDIS_OK)
         return REDIS_ERR;
 
+    /* Don't leak sockaddr if we're reconnecting */
+    if (c->saddr) hi_free(c->saddr);
+
     sa = (struct sockaddr_un*)(c->saddr = hi_malloc(sizeof(struct sockaddr_un)));
+    if (sa == NULL)
+        goto oom;
+
     c->addrlen = sizeof(struct sockaddr_un);
     sa->sun_family = AF_UNIX;
     strncpy(sa->sun_path, path, sizeof(sa->sun_path) - 1);
@@ -564,4 +590,7 @@ int redisContextConnectUnix(redisContext *c, const char *path, const struct time
     errno = EPROTONOSUPPORT;
     return REDIS_ERR;
 #endif /* _WIN32 */
+oom:
+    __redisSetError(c, REDIS_ERR_OOM, "Out of memory");
+    return REDIS_ERR;
 }
diff --git a/read.c b/read.c
index 4924014..d10b62a 100644
--- a/read.c
+++ b/read.c
@@ -42,6 +42,7 @@
 #include <limits.h>
 #include <math.h>
 
+#include "alloc.h"
 #include "read.h"
 #include "sds.h"
 #include "win32.h"
@@ -425,7 +426,7 @@ static int redisReaderGrow(redisReader *r) {
 
     /* Grow our stack size */
     newlen = r->tasks + REDIS_READER_STACK_SIZE;
-    aux = realloc(r->task, sizeof(*r->task) * newlen);
+    aux = hi_realloc(r->task, sizeof(*r->task) * newlen);
     if (aux == NULL)
         goto oom;
 
@@ -433,7 +434,7 @@ static int redisReaderGrow(redisReader *r) {
 
     /* Allocate new tasks */
     for (; r->tasks < newlen; r->tasks++) {
-        r->task[r->tasks] = calloc(1, sizeof(**r->task));
+        r->task[r->tasks] = hi_calloc(1, sizeof(**r->task));
         if (r->task[r->tasks] == NULL)
             goto oom;
     }
@@ -467,7 +468,9 @@ static int processAggregateItem(redisReader *r) {
 
         root = (r->ridx == 0);
 
-        if (elements < -1 || (LLONG_MAX > SIZE_MAX && elements > SIZE_MAX)) {
+        if (elements < -1 || (LLONG_MAX > SIZE_MAX && elements > SIZE_MAX) ||
+            (r->maxelements > 0 && elements > r->maxelements))
+        {
             __redisReaderSetError(r,REDIS_ERR_PROTOCOL,
                     "Multi-bulk length out of range");
             return REDIS_ERR;
@@ -602,7 +605,7 @@ static int processItem(redisReader *r) {
 redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn) {
     redisReader *r;
 
-    r = calloc(1,sizeof(redisReader));
+    r = hi_calloc(1,sizeof(redisReader));
     if (r == NULL)
         return NULL;
 
@@ -610,22 +613,22 @@ redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn) {
     if (r->buf == NULL)
         goto oom;
 
-    r->task = calloc(REDIS_READER_STACK_SIZE, sizeof(*r->task));
+    r->task = hi_calloc(REDIS_READER_STACK_SIZE, sizeof(*r->task));
     if (r->task == NULL)
         goto oom;
 
     for (; r->tasks < REDIS_READER_STACK_SIZE; r->tasks++) {
-        r->task[r->tasks] = calloc(1, sizeof(**r->task));
+        r->task[r->tasks] = hi_calloc(1, sizeof(**r->task));
         if (r->task[r->tasks] == NULL)
             goto oom;
     }
 
     r->fn = fn;
     r->maxbuf = REDIS_READER_MAX_BUF;
-
+    r->maxelements = REDIS_READER_MAX_ARRAY_ELEMENTS;
     r->ridx = -1;
-    return r;
 
+    return r;
 oom:
     redisReaderFree(r);
     return NULL;
@@ -640,14 +643,14 @@ void redisReaderFree(redisReader *r) {
 
     /* We know r->task[i] is allocatd if i < r->tasks */
     for (int i = 0; i < r->tasks; i++) {
-        free(r->task[i]);
+        hi_free(r->task[i]);
     }
 
     if (r->task)
-        free(r->task);
+        hi_free(r->task);
 
     sdsfree(r->buf);
-    free(r);
+    hi_free(r);
 }
 
 int redisReaderFeed(redisReader *r, const char *buf, size_t len) {
@@ -663,23 +666,22 @@ int redisReaderFeed(redisReader *r, const char *buf, size_t len) {
         if (r->len == 0 && r->maxbuf != 0 && sdsavail(r->buf) > r->maxbuf) {
             sdsfree(r->buf);
             r->buf = sdsempty();
-            r->pos = 0;
+            if (r->buf == 0) goto oom;
 
-            /* r->buf should not be NULL since we just free'd a larger one. */
-            assert(r->buf != NULL);
+            r->pos = 0;
         }
 
         newbuf = sdscatlen(r->buf,buf,len);
-        if (newbuf == NULL) {
-            __redisReaderSetErrorOOM(r);
-            return REDIS_ERR;
-        }
+        if (newbuf == NULL) goto oom;
 
         r->buf = newbuf;
         r->len = sdslen(r->buf);
     }
 
     return REDIS_OK;
+oom:
+    __redisReaderSetErrorOOM(r);
+    return REDIS_ERR;
 }
 
 int redisReaderGetReply(redisReader *r, void **reply) {
diff --git a/read.h b/read.h
index 788c401..2d74d77 100644
--- a/read.h
+++ b/read.h
@@ -63,7 +63,11 @@
 #define REDIS_REPLY_BIGNUM 13
 #define REDIS_REPLY_VERB 14
 
-#define REDIS_READER_MAX_BUF (1024*16)  /* Default max unused reader buffer. */
+/* Default max unused reader buffer. */
+#define REDIS_READER_MAX_BUF (1024*16)
+
+/* Default multi-bulk element limit */
+#define REDIS_READER_MAX_ARRAY_ELEMENTS ((1LL<<32) - 1)
 
 #ifdef __cplusplus
 extern "C" {
@@ -71,7 +75,7 @@ extern "C" {
 
 typedef struct redisReadTask {
     int type;
-    int elements; /* number of elements in multibulk container */
+    long long elements; /* number of elements in multibulk container */
     int idx; /* index in parent (array) object */
     void *obj; /* holds user-generated value for a read task */
     struct redisReadTask *parent; /* parent task */
@@ -96,6 +100,7 @@ typedef struct redisReader {
     size_t pos; /* Buffer cursor */
     size_t len; /* Buffer length */
     size_t maxbuf; /* Max length of unused buffer */
+    long long maxelements; /* Max multi-bulk elements */
 
     redisReadTask **task;
     int tasks;
diff --git a/sds.c b/sds.c
index e8b996a..f7811a7 100644
--- a/sds.c
+++ b/sds.c
@@ -30,6 +30,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "fmacros.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -219,10 +220,7 @@ sds sdsMakeRoomFor(sds s, size_t addlen) {
     hdrlen = sdsHdrSize(type);
     if (oldtype==type) {
         newsh = s_realloc(sh, hdrlen+newlen+1);
-        if (newsh == NULL) {
-            s_free(sh);
-            return NULL;
-        }
+        if (newsh == NULL) return NULL;
         s = (char*)newsh+hdrlen;
     } else {
         /* Since the header size changes, need to move the string forward,
diff --git a/sdsalloc.h b/sdsalloc.h
index f43023c..5538dd9 100644
--- a/sdsalloc.h
+++ b/sdsalloc.h
@@ -37,6 +37,8 @@
  * the include of your alternate allocator if needed (not needed in order
  * to use the default libc allocator). */
 
-#define s_malloc malloc
-#define s_realloc realloc
-#define s_free free
+#include "alloc.h"
+
+#define s_malloc hi_malloc
+#define s_realloc hi_realloc
+#define s_free hi_free
diff --git a/ssl.c b/ssl.c
index 502814d..8cb133a 100644
--- a/ssl.c
+++ b/ssl.c
@@ -163,18 +163,22 @@ static void opensslDoLock(int mode, int lkid, const char *f, int line) {
     (void)line;
 }
 
-static void initOpensslLocks(void) {
+static int initOpensslLocks(void) {
     unsigned ii, nlocks;
     if (CRYPTO_get_locking_callback() != NULL) {
         /* Someone already set the callback before us. Don't destroy it! */
-        return;
+        return REDIS_OK;
     }
     nlocks = CRYPTO_num_locks();
     ossl_locks = hi_malloc(sizeof(*ossl_locks) * nlocks);
+    if (ossl_locks == NULL)
+        return REDIS_ERR;
+
     for (ii = 0; ii < nlocks; ii++) {
         sslLockInit(ossl_locks + ii);
     }
     CRYPTO_set_locking_callback(opensslDoLock);
+    return REDIS_OK;
 }
 #endif /* HIREDIS_USE_CRYPTO_LOCKS */
 
@@ -183,15 +187,20 @@ static void initOpensslLocks(void) {
  */
 
 static int redisSSLConnect(redisContext *c, SSL_CTX *ssl_ctx, SSL *ssl) {
+    redisSSLContext *rssl;
+
     if (c->privdata) {
         __redisSetError(c, REDIS_ERR_OTHER, "redisContext was already associated");
         return REDIS_ERR;
     }
-    c->privdata = calloc(1, sizeof(redisSSLContext));
 
-    c->funcs = &redisContextSSLFuncs;
-    redisSSLContext *rssl = c->privdata;
+    rssl = hi_calloc(1, sizeof(redisSSLContext));
+    if (rssl == NULL) {
+        __redisSetError(c, REDIS_ERR_OOM, "Out of memory");
+        return REDIS_ERR;
+    }
 
+    c->funcs = &redisContextSSLFuncs;
     rssl->ssl_ctx = ssl_ctx;
     rssl->ssl = ssl;
 
@@ -202,12 +211,14 @@ static int redisSSLConnect(redisContext *c, SSL_CTX *ssl_ctx, SSL *ssl) {
     ERR_clear_error();
     int rv = SSL_connect(rssl->ssl);
     if (rv == 1) {
+        c->privdata = rssl;
         return REDIS_OK;
     }
 
     rv = SSL_get_error(rssl->ssl, rv);
     if (((c->flags & REDIS_BLOCK) == 0) &&
         (rv == SSL_ERROR_WANT_READ || rv == SSL_ERROR_WANT_WRITE)) {
+        c->privdata = rssl;
         return REDIS_OK;
     }
 
@@ -222,6 +233,8 @@ static int redisSSLConnect(redisContext *c, SSL_CTX *ssl_ctx, SSL *ssl) {
         }
         __redisSetError(c, REDIS_ERR_IO, err);
     }
+
+    hi_free(rssl);
     return REDIS_ERR;
 }
 
@@ -241,7 +254,10 @@ int redisSecureConnection(redisContext *c, const char *capath,
         isInit = 1;
         SSL_library_init();
 #ifdef HIREDIS_USE_CRYPTO_LOCKS
-        initOpensslLocks();
+        if (initOpensslLocks() == REDIS_ERR) {
+            __redisSetError(c, REDIS_ERR_OOM, "Out of memory");
+            goto error;
+        }
 #endif
     }
 
@@ -290,7 +306,8 @@ int redisSecureConnection(redisContext *c, const char *capath,
         }
     }
 
-    return redisSSLConnect(c, ssl_ctx, ssl);
+    if (redisSSLConnect(c, ssl_ctx, ssl) == REDIS_OK)
+        return REDIS_OK;
 
 error:
     if (ssl) SSL_free(ssl);
@@ -330,7 +347,7 @@ static void redisSSLFreeContext(void *privdata){
         SSL_CTX_free(rsc->ssl_ctx);
         rsc->ssl_ctx = NULL;
     }
-    free(rsc);
+    hi_free(rsc);
 }
 
 static int redisSSLRead(redisContext *c, char *buf, size_t bufcap) {
diff --git a/test.c b/test.c
index 1d38caa..48d36d0 100644
--- a/test.c
+++ b/test.c
@@ -180,43 +180,43 @@ static void test_format_commands(void) {
     len = redisFormatCommand(&cmd,"SET foo bar");
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\nbar\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(3+2)+4+(3+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command with %%s string interpolation: ");
     len = redisFormatCommand(&cmd,"SET %s %s","foo","bar");
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\nbar\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(3+2)+4+(3+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command with %%s and an empty string: ");
     len = redisFormatCommand(&cmd,"SET %s %s","foo","");
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$0\r\n\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(3+2)+4+(0+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command with an empty string in between proper interpolations: ");
     len = redisFormatCommand(&cmd,"SET %s %s","","foo");
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$0\r\n\r\n$3\r\nfoo\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(0+2)+4+(3+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command with %%b string interpolation: ");
     len = redisFormatCommand(&cmd,"SET %b %b","foo",(size_t)3,"b\0r",(size_t)3);
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\nb\0r\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(3+2)+4+(3+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command with %%b and an empty string: ");
     len = redisFormatCommand(&cmd,"SET %b %b","foo",(size_t)3,"",(size_t)0);
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$0\r\n\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(3+2)+4+(0+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command with literal %%: ");
     len = redisFormatCommand(&cmd,"SET %% %%");
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$1\r\n%\r\n$1\r\n%\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(1+2)+4+(1+2));
-    free(cmd);
+    hi_free(cmd);
 
     /* Vararg width depends on the type. These tests make sure that the
      * width is correctly determined using the format and subsequent varargs
@@ -227,7 +227,7 @@ static void test_format_commands(void) {
     len = redisFormatCommand(&cmd,"key:%08" fmt " str:%s", value, "hello");               \
     test_cond(strncmp(cmd,"*2\r\n$12\r\nkey:00000123\r\n$9\r\nstr:hello\r\n",len) == 0 && \
         len == 4+5+(12+2)+4+(9+2));                                                       \
-    free(cmd);                                                                            \
+    hi_free(cmd);                                                                         \
 } while(0)
 
 #define FLOAT_WIDTH_TEST(type) do {                                                       \
@@ -236,7 +236,7 @@ static void test_format_commands(void) {
     len = redisFormatCommand(&cmd,"key:%08.3f str:%s", value, "hello");                   \
     test_cond(strncmp(cmd,"*2\r\n$12\r\nkey:0123.000\r\n$9\r\nstr:hello\r\n",len) == 0 && \
         len == 4+5+(12+2)+4+(9+2));                                                       \
-    free(cmd);                                                                            \
+    hi_free(cmd);                                                                         \
 } while(0)
 
     INTEGER_WIDTH_TEST("d", int);
@@ -267,13 +267,13 @@ static void test_format_commands(void) {
     len = redisFormatCommandArgv(&cmd,argc,argv,NULL);
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$3\r\nfoo\r\n$3\r\nbar\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(3+2)+4+(3+2));
-    free(cmd);
+    hi_free(cmd);
 
     test("Format command by passing argc/argv with lengths: ");
     len = redisFormatCommandArgv(&cmd,argc,argv,lens);
     test_cond(strncmp(cmd,"*3\r\n$3\r\nSET\r\n$7\r\nfoo\0xxx\r\n$3\r\nbar\r\n",len) == 0 &&
         len == 4+4+(3+2)+4+(7+2)+4+(3+2));
-    free(cmd);
+    hi_free(cmd);
 
     sds sds_cmd;
 
@@ -308,7 +308,7 @@ static void test_append_formatted_commands(struct config config) {
 
     assert(redisGetReply(c, (void*)&reply) == REDIS_OK);
 
-    free(cmd);
+    hi_free(cmd);
     freeReplyObject(reply);
 
     disconnect(c, 0);
@@ -418,6 +418,16 @@ static void test_reply_reader(void) {
     freeReplyObject(reply);
     redisReaderFree(reader);
 
+    test("Can configure maximum multi-bulk elements: ");
+    reader = redisReaderCreate();
+    reader->maxelements = 1024;
+    redisReaderFeed(reader, "*1025\r\n", 7);
+    ret = redisReaderGetReply(reader,&reply);
+    test_cond(ret == REDIS_ERR &&
+              strcasecmp(reader->errstr, "Multi-bulk length out of range") == 0);
+    freeReplyObject(reply);
+    redisReaderFree(reader);
+
 #if LLONG_MAX > SIZE_MAX
     test("Set error when array > SIZE_MAX: ");
     reader = redisReaderCreate();
@@ -518,6 +528,46 @@ static void test_free_null(void) {
     test_cond(reply == NULL);
 }
 
+static void *hi_malloc_fail(size_t size) {
+    (void)size;
+    return NULL;
+}
+
+static void *hi_calloc_fail(size_t nmemb, size_t size) {
+    (void)nmemb;
+    (void)size;
+    return NULL;
+}
+
+static void *hi_realloc_fail(void *ptr, size_t size) {
+    (void)ptr;
+    (void)size;
+    return NULL;
+}
+
+static void test_allocator_injection(void) {
+    hiredisAllocFuncs ha = {
+        .malloc = hi_malloc_fail,
+        .calloc = hi_calloc_fail,
+        .realloc = hi_realloc_fail,
+        .free = NULL,
+    };
+
+    // Override hiredis allocators
+    hiredisSetAllocators(&ha);
+
+    test("redisContext uses injected allocators: ");
+    redisContext *c = redisConnect("localhost", 6379);
+    test_cond(c == NULL);
+
+    test("redisReader uses injected allocators: ");
+    redisReader *reader = redisReaderCreate();
+    test_cond(reader == NULL);
+
+    // Return allocators to default
+    hiredisResetAllocators();
+}
+
 #define HIREDIS_BAD_DOMAIN "idontexist-noreally.com"
 static void test_blocking_connection_errors(void) {
     redisContext *c;
@@ -799,6 +849,18 @@ static void test_invalid_timeout_errors(struct config config) {
     redisFree(c);
 }
 
+/* Wrap malloc to abort on failure so OOM checks don't make the test logic
+ * harder to follow. */
+void *hi_malloc_safe(size_t size) {
+    void *ptr = hi_malloc(size);
+    if (ptr == NULL) {
+        fprintf(stderr, "Error:  Out of memory\n");
+        exit(-1);
+    }
+
+    return ptr;
+}
+
 static void test_throughput(struct config config) {
     redisContext *c = do_connect(config);
     redisReply **replies;
@@ -810,7 +872,7 @@ static void test_throughput(struct config config) {
         freeReplyObject(redisCommand(c,"LPUSH mylist foo"));
 
     num = 1000;
-    replies = malloc(sizeof(redisReply*)*num);
+    replies = hi_malloc_safe(sizeof(redisReply*)*num);
     t1 = usec();
     for (i = 0; i < num; i++) {
         replies[i] = redisCommand(c,"PING");
@@ -818,10 +880,10 @@ static void test_throughput(struct config config) {
     }
     t2 = usec();
     for (i = 0; i < num; i++) freeReplyObject(replies[i]);
-    free(replies);
+    hi_free(replies);
     printf("\t(%dx PING: %.3fs)\n", num, (t2-t1)/1000000.0);
 
-    replies = malloc(sizeof(redisReply*)*num);
+    replies = hi_malloc_safe(sizeof(redisReply*)*num);
     t1 = usec();
     for (i = 0; i < num; i++) {
         replies[i] = redisCommand(c,"LRANGE mylist 0 499");
@@ -830,10 +892,10 @@ static void test_throughput(struct config config) {
     }
     t2 = usec();
     for (i = 0; i < num; i++) freeReplyObject(replies[i]);
-    free(replies);
+    hi_free(replies);
     printf("\t(%dx LRANGE with 500 elements: %.3fs)\n", num, (t2-t1)/1000000.0);
 
-    replies = malloc(sizeof(redisReply*)*num);
+    replies = hi_malloc_safe(sizeof(redisReply*)*num);
     t1 = usec();
     for (i = 0; i < num; i++) {
         replies[i] = redisCommand(c, "INCRBY incrkey %d", 1000000);
@@ -841,11 +903,11 @@ static void test_throughput(struct config config) {
     }
     t2 = usec();
     for (i = 0; i < num; i++) freeReplyObject(replies[i]);
-    free(replies);
+    hi_free(replies);
     printf("\t(%dx INCRBY: %.3fs)\n", num, (t2-t1)/1000000.0);
 
     num = 10000;
-    replies = malloc(sizeof(redisReply*)*num);
+    replies = hi_malloc_safe(sizeof(redisReply*)*num);
     for (i = 0; i < num; i++)
         redisAppendCommand(c,"PING");
     t1 = usec();
@@ -855,10 +917,10 @@ static void test_throughput(struct config config) {
     }
     t2 = usec();
     for (i = 0; i < num; i++) freeReplyObject(replies[i]);
-    free(replies);
+    hi_free(replies);
     printf("\t(%dx PING (pipelined): %.3fs)\n", num, (t2-t1)/1000000.0);
 
-    replies = malloc(sizeof(redisReply*)*num);
+    replies = hi_malloc_safe(sizeof(redisReply*)*num);
     for (i = 0; i < num; i++)
         redisAppendCommand(c,"LRANGE mylist 0 499");
     t1 = usec();
@@ -869,10 +931,10 @@ static void test_throughput(struct config config) {
     }
     t2 = usec();
     for (i = 0; i < num; i++) freeReplyObject(replies[i]);
-    free(replies);
+    hi_free(replies);
     printf("\t(%dx LRANGE with 500 elements (pipelined): %.3fs)\n", num, (t2-t1)/1000000.0);
 
-    replies = malloc(sizeof(redisReply*)*num);
+    replies = hi_malloc_safe(sizeof(redisReply*)*num);
     for (i = 0; i < num; i++)
         redisAppendCommand(c,"INCRBY incrkey %d", 1000000);
     t1 = usec();
@@ -882,7 +944,7 @@ static void test_throughput(struct config config) {
     }
     t2 = usec();
     for (i = 0; i < num; i++) freeReplyObject(replies[i]);
-    free(replies);
+    hi_free(replies);
     printf("\t(%dx INCRBY (pipelined): %.3fs)\n", num, (t2-t1)/1000000.0);
 
     disconnect(c, 0);
@@ -1049,11 +1111,14 @@ int main(int argc, char **argv) {
     signal(SIGPIPE, SIG_IGN);
 
     test_unix_socket = access(cfg.unix_sock.path, F_OK) == 0;
+
 #else
     /* Unix sockets don't exist in Windows */
     test_unix_socket = 0;
 #endif
 
+    test_allocator_injection();
+
     test_format_commands();
     test_reply_reader();
     test_blocking_connection_errors();