refactor: Add mem module to allow tests to override allocators.

This will allow us to do more interesting things with memory allocation
within toxcore, and allow fuzzers to explore various allocation failure
paths.

toxcore/BUILD.bazel

@@ -15,6 +15,13 @@ cc_library(
     visibility = ["//c-toxcore:__subpackages__"],
 )
 
+cc_library(
+    name = "mem",
+    srcs = ["mem.c"],
+    hdrs = ["mem.h"],
+    visibility = ["//c-toxcore:__subpackages__"],
+)
+
 cc_library(
     name = "ccompat",
     srcs = ["ccompat.c"],
@@ -766,6 +773,7 @@ cc_library(
         ":group",
         ":group_moderation",
         ":logger",
+        ":mem",
         ":mono_time",
         ":network",
         "//c-toxcore/toxencryptsave:defines",

toxcore/mem.c

@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright © 2016-2018 The TokTok team.
+ * Copyright © 2013 Tox project.
+ */
+
+#include "mem.h"
+
+#include <stdlib.h>
+
+static void *sys_malloc(void *obj, uint32_t size)
+{
+    return malloc(size);
+}
+
+static void *sys_calloc(void *obj, uint32_t nmemb, uint32_t size)
+{
+    return calloc(nmemb, size);
+}
+
+static void *sys_realloc(void *obj, void *ptr, uint32_t size)
+{
+    return realloc(ptr, size);
+}
+
+static void sys_free(void *obj, void *ptr)
+{
+    free(ptr);
+}
+
+static const Memory_Funcs system_memory_funcs = {
+    sys_malloc,
+    sys_calloc,
+    sys_realloc,
+    sys_free,
+};
+static const Memory system_memory_obj = {&system_memory_funcs};
+
+const Memory *system_memory(void)
+{
+    return &system_memory_obj;
+}
+
+void *mem_malloc(const Memory *mem, uint32_t size)
+{
+    return mem->funcs->malloc(mem->obj, size);
+}
+
+void *mem_calloc(const Memory *mem, uint32_t nmemb, uint32_t size)
+{
+    return mem->funcs->calloc(mem->obj, nmemb, size);
+}
+
+void *mem_realloc(const Memory *mem, void *ptr, uint32_t size)
+{
+    return mem->funcs->realloc(mem->obj, ptr, size);
+}
+
+void mem_free(const Memory *mem, void *ptr)
+{
+    mem->funcs->free(mem->obj, ptr);
+}

toxcore/mem.h

@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later
+ * Copyright © 2016-2018 The TokTok team.
+ * Copyright © 2013 Tox project.
+ */
+
+/**
+ * Datatypes, functions and includes for the core networking.
+ */
+#ifndef C_TOXCORE_TOXCORE_MEM_H
+#define C_TOXCORE_TOXCORE_MEM_H
+
+#include <stdint.h>     // uint*_t
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void *mem_malloc_cb(void *obj, uint32_t size);
+typedef void *mem_calloc_cb(void *obj, uint32_t nmemb, uint32_t size);
+typedef void *mem_realloc_cb(void *obj, void *ptr, uint32_t size);
+typedef void mem_free_cb(void *obj, void *ptr);
+
+/** @brief Functions wrapping standard C memory allocation functions. */
+typedef struct Memory_Funcs {
+    mem_malloc_cb *malloc;
+    mem_calloc_cb *calloc;
+    mem_realloc_cb *realloc;
+    mem_free_cb *free;
+} Memory_Funcs;
+
+typedef struct Memory {
+    const Memory_Funcs *funcs;
+    void *obj;
+} Memory;
+
+const Memory *system_memory(void);
+
+void *mem_malloc(const Memory *mem, uint32_t size);
+void *mem_calloc(const Memory *mem, uint32_t nmemb, uint32_t size);
+void *mem_realloc(const Memory *mem, void *ptr, uint32_t size);
+void mem_free(const Memory *mem, void *ptr);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif

toxcore/tox.c

@@ -22,6 +22,7 @@
 #include "group_chats.h"
 #include "group_moderation.h"
 #include "logger.h"
+#include "mem.h"
 #include "mono_time.h"
 #include "network.h"
 #include "tox_private.h"
@@ -626,18 +627,6 @@ static int tox_load(Tox *tox, const uint8_t *data, uint32_t length)
 
 Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
 {
-    Tox *tox = (Tox *)calloc(1, sizeof(Tox));
-
-    if (tox == nullptr) {
-        SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
-        return nullptr;
-    }
-
-    Messenger_Options m_options = {0};
-
-    bool load_savedata_sk = false;
-    bool load_savedata_tox = false;
-
     struct Tox_Options *default_options = nullptr;
 
     if (options == nullptr) {
@@ -651,7 +640,6 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
 
             case TOX_ERR_OPTIONS_NEW_MALLOC: {
                 SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
-                free(tox);
                 return nullptr;
             }
         }
@@ -660,11 +648,28 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
     const struct Tox_Options *const opts = options != nullptr ? options : default_options;
     assert(opts != nullptr);
 
+    const Tox_System *sys = tox_options_get_operating_system(opts);
+    const Tox_System default_system = tox_default_system();
+
+    if (sys == nullptr) {
+        sys = &default_system;
+    }
+
+    if (sys->rng == nullptr || sys->ns == nullptr || sys->mem == nullptr) {
+        // TODO(iphydf): Not quite right, but similar.
+        SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
+        return nullptr;
+    }
+
+    Messenger_Options m_options = {0};
+
+    bool load_savedata_sk = false;
+    bool load_savedata_tox = false;
+
     if (tox_options_get_savedata_type(opts) != TOX_SAVEDATA_TYPE_NONE) {
         if (tox_options_get_savedata_data(opts) == nullptr || tox_options_get_savedata_length(opts) == 0) {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_LOAD_BAD_FORMAT);
             tox_options_free(default_options);
-            free(tox);
             return nullptr;
         }
     }
@@ -673,7 +678,6 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
         if (tox_options_get_savedata_length(opts) != TOX_SECRET_KEY_SIZE) {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_LOAD_BAD_FORMAT);
             tox_options_free(default_options);
-            free(tox);
             return nullptr;
         }
 
@@ -682,14 +686,12 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
         if (tox_options_get_savedata_length(opts) < TOX_ENC_SAVE_MAGIC_LENGTH) {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_LOAD_BAD_FORMAT);
             tox_options_free(default_options);
-            free(tox);
             return nullptr;
         }
 
         if (memcmp(tox_options_get_savedata_data(opts), TOX_ENC_SAVE_MAGIC_NUMBER, TOX_ENC_SAVE_MAGIC_LENGTH) == 0) {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_LOAD_ENCRYPTED);
             tox_options_free(default_options);
-            free(tox);
             return nullptr;
         }
 
@@ -709,6 +711,13 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
         m_options.local_discovery_enabled = false;
     }
 
+    Tox *tox = (Tox *)mem_calloc(sys->mem, 1, sizeof(Tox));
+
+    if (tox == nullptr) {
+        SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
+        return nullptr;
+    }
+
     tox->log_callback = tox_options_get_log_callback(opts);
     m_options.log_callback = tox_log_handler;
     m_options.log_context = tox;
@@ -733,34 +742,20 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
         default: {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_PROXY_BAD_TYPE);
             tox_options_free(default_options);
-            free(tox);
+            mem_free(sys->mem, tox);
             return nullptr;
         }
     }
 
-    const Tox_System *sys = tox_options_get_operating_system(opts);
-    const Tox_System default_system = tox_default_system();
-
-    if (sys == nullptr) {
-        sys = &default_system;
-    }
-
-    if (sys->rng == nullptr || sys->ns == nullptr) {
-        // TODO(iphydf): Not quite right, but similar.
-        SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
-        tox_options_free(default_options);
-        free(tox);
-        return nullptr;
-    }
-
     tox->rng = *sys->rng;
     tox->ns = *sys->ns;
+    tox->mem = *sys->mem;
 
     if (m_options.proxy_info.proxy_type != TCP_PROXY_NONE) {
         if (tox_options_get_proxy_port(opts) == 0) {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_PROXY_BAD_PORT);
             tox_options_free(default_options);
-            free(tox);
+            mem_free(sys->mem, tox);
             return nullptr;
         }
 
@@ -777,7 +772,7 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_PROXY_BAD_HOST);
             // TODO(irungentoo): TOX_ERR_NEW_PROXY_NOT_FOUND if domain.
             tox_options_free(default_options);
-            free(tox);
+            mem_free(sys->mem, tox);
             return nullptr;
         }
 
@@ -789,17 +784,17 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
     if (tox->mono_time == nullptr) {
         SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
         tox_options_free(default_options);
-        free(tox);
+        mem_free(sys->mem, tox);
         return nullptr;
     }
 
     if (tox_options_get_experimental_thread_safety(opts)) {
-        tox->mutex = (pthread_mutex_t *)calloc(1, sizeof(pthread_mutex_t));
+        tox->mutex = (pthread_mutex_t *)mem_calloc(sys->mem, 1, sizeof(pthread_mutex_t));
 
         if (tox->mutex == nullptr) {
             SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
             tox_options_free(default_options);
-            free(tox);
+            mem_free(sys->mem, tox);
             return nullptr;
         }
 
@@ -835,8 +830,8 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
             pthread_mutex_destroy(tox->mutex);
         }
 
-        free(tox->mutex);
-        free(tox);
+        mem_free(sys->mem, tox->mutex);
+        mem_free(sys->mem, tox);
         return nullptr;
     }
 
@@ -851,8 +846,8 @@ Tox *tox_new(const struct Tox_Options *options, Tox_Err_New *error)
             pthread_mutex_destroy(tox->mutex);
         }
 
-        free(tox->mutex);
-        free(tox);
+        mem_free(sys->mem, tox->mutex);
+        mem_free(sys->mem, tox);
 
         SET_ERROR_PARAMETER(error, TOX_ERR_NEW_MALLOC);
         return nullptr;
@@ -933,10 +928,10 @@ void tox_kill(Tox *tox)
 
     if (tox->mutex != nullptr) {
         pthread_mutex_destroy(tox->mutex);
-        free(tox->mutex);
+        mem_free(&tox->mem, tox->mutex);
     }
 
-    free(tox);
+    mem_free(&tox->mem, tox);
 }
 
 static uint32_t end_size(void)

toxcore/tox_private.c

@@ -11,6 +11,7 @@
 #include <assert.h>
 
 #include "ccompat.h"
+#include "mem.h"
 #include "network.h"
 #include "tox_struct.h"
 
@@ -28,6 +29,7 @@ Tox_System tox_default_system(void)
         nullptr,  // mono_time_user_data
         system_random(),
         system_network(),
+        system_memory(),
     };
     return sys;
 }

toxcore/tox_private.h

@@ -23,6 +23,7 @@ struct Tox_System {
     void *mono_time_user_data;
     const struct Random *rng;
     const struct Network *ns;
+    const struct Memory *mem;
 };
 
 Tox_System tox_default_system(void);

toxcore/tox_struct.h

@@ -7,6 +7,7 @@
 #define C_TOXCORE_TOXCORE_TOX_STRUCT_H
 
 #include "Messenger.h"
+#include "mem.h"
 #include "tox.h"
 #include "tox_private.h"
 
@@ -19,6 +20,7 @@ struct Tox {
     Mono_Time *mono_time;
     Random rng;
     Network ns;
+    Memory mem;
     pthread_mutex_t *mutex;
 
     tox_log_cb *log_callback;