From eac45e29196bcde1d123a6035c15d30356bed248 Mon Sep 17 00:00:00 2001
From: Gregory Oschwald <goschwald@maxmind.com>
Date: Wed, 5 Aug 2020 14:16:17 -0700
Subject: [PATCH] Replace most malloc uses with calloc

Closes #236.
---
 bin/mmdblookup.c    |  2 +-
 doc/libmaxminddb.md |  2 +-
 src/maxminddb.c     | 19 +++++++++++--------
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/bin/mmdblookup.c b/bin/mmdblookup.c
index 26267c4..7f78773 100644
--- a/bin/mmdblookup.c
+++ b/bin/mmdblookup.c
@@ -184,7 +184,7 @@ LOCAL const char **get_options(int argc, char **argv, char **mmdb_file,
     }
 
     const char **lookup_path =
-        malloc(sizeof(const char *) * ((argc - optind) + 1));
+        calloc((argc - optind) + 1, sizeof(const char *));
     int i;
     for (i = 0; i < argc - optind; i++) {
         lookup_path[i] = argv[i + optind];
diff --git a/doc/libmaxminddb.md b/doc/libmaxminddb.md
index ebeb7c5..a8385e0 100644
--- a/doc/libmaxminddb.md
+++ b/doc/libmaxminddb.md
@@ -302,7 +302,7 @@ libmaxminddb code.
 
 The `utf8_string`, `bytes`, and (maybe) the `uint128` members of this structure
 are all pointers directly into the database's data section. This can either be
-a `malloc`'d or `mmap`'d block of memory. In either case, these pointers will
+a `calloc`'d or `mmap`'d block of memory. In either case, these pointers will
 become invalid after `MMDB_close()` is called.
 
 If you need to refer to this data after that time you should copy the data
diff --git a/src/maxminddb.c b/src/maxminddb.c
index 1cf2cbc..f8bbecb 100644
--- a/src/maxminddb.c
+++ b/src/maxminddb.c
@@ -34,7 +34,7 @@
     do {                                                        \
         char *binary = byte_to_binary(byte);                    \
         if (NULL == binary) {                                   \
-            fprintf(stderr, "Malloc failed in DEBUG_BINARY\n"); \
+            fprintf(stderr, "Calloc failed in DEBUG_BINARY\n"); \
             abort();                                            \
         }                                                       \
         fprintf(stderr, fmt "\n", binary);                      \
@@ -53,7 +53,7 @@
 #ifdef MMDB_DEBUG
 DEBUG_FUNC char *byte_to_binary(uint8_t byte)
 {
-    char *bits = malloc(sizeof(char) * 9);
+    char *bits = calloc(9, sizeof(char));
     if (NULL == bits) {
         return bits;
     }
@@ -658,7 +658,7 @@ LOCAL int populate_languages_metadata(MMDB_s *mmdb, MMDB_s *metadata_db,
                               MMDB_INVALID_METADATA_ERROR);
 
     mmdb->metadata.languages.count = 0;
-    mmdb->metadata.languages.names = malloc(array_size * sizeof(char *));
+    mmdb->metadata.languages.names = calloc(array_size, sizeof(char *));
     if (NULL == mmdb->metadata.languages.names) {
         return MMDB_OUT_OF_MEMORY_ERROR;
     }
@@ -676,7 +676,7 @@ LOCAL int populate_languages_metadata(MMDB_s *mmdb, MMDB_s *metadata_db,
         if (NULL == mmdb->metadata.languages.names[i]) {
             return MMDB_OUT_OF_MEMORY_ERROR;
         }
-        // We assign this as we go so that if we fail a malloc and need to
+        // We assign this as we go so that if we fail a calloc and need to
         // free it, the count is right.
         mmdb->metadata.languages.count = i + 1;
     }
@@ -728,7 +728,7 @@ LOCAL int populate_description_metadata(MMDB_s *mmdb, MMDB_s *metadata_db,
                               MMDB_INVALID_METADATA_ERROR);
 
     mmdb->metadata.description.descriptions =
-        malloc(map_size * sizeof(MMDB_description_s *));
+        calloc(map_size, sizeof(MMDB_description_s *));
     if (NULL == mmdb->metadata.description.descriptions) {
         status = MMDB_OUT_OF_MEMORY_ERROR;
         goto cleanup;
@@ -736,7 +736,7 @@ LOCAL int populate_description_metadata(MMDB_s *mmdb, MMDB_s *metadata_db,
 
     for (uint32_t i = 0; i < map_size; i++) {
         mmdb->metadata.description.descriptions[i] =
-            malloc(sizeof(MMDB_description_s));
+            calloc(1, sizeof(MMDB_description_s));
         if (NULL == mmdb->metadata.description.descriptions[i]) {
             status = MMDB_OUT_OF_MEMORY_ERROR;
             goto cleanup;
@@ -1140,7 +1140,7 @@ int MMDB_vget_value(MMDB_entry_s *const start,
     MAYBE_CHECK_SIZE_OVERFLOW(length, SIZE_MAX / sizeof(const char *) - 1,
                               MMDB_INVALID_METADATA_ERROR);
 
-    const char **path = malloc((length + 1) * sizeof(const char *));
+    const char **path = calloc(length + 1, sizeof(const char *));
     if (NULL == path) {
         return MMDB_OUT_OF_MEMORY_ERROR;
     }
@@ -2000,6 +2000,7 @@ LOCAL MMDB_entry_data_list_s *dump_entry_data_list(
             char *hex_string =
                 bytes_to_hex((uint8_t *)entry_data_list->entry_data.bytes,
                              entry_data_list->entry_data.data_size);
+
             if (NULL == hex_string) {
                 *status = MMDB_OUT_OF_MEMORY_ERROR;
                 return NULL;
@@ -2093,7 +2094,7 @@ LOCAL char *bytes_to_hex(uint8_t *bytes, uint32_t size)
     char *hex_string;
     MAYBE_CHECK_SIZE_OVERFLOW(size, SIZE_MAX / 2 - 1, NULL);
 
-    hex_string = malloc((size * 2) + 1);
+    hex_string = calloc((size * 2) + 1, sizeof(char));
     if (NULL == hex_string) {
         return NULL;
     }
@@ -2102,6 +2103,8 @@ LOCAL char *bytes_to_hex(uint8_t *bytes, uint32_t size)
         sprintf(hex_string + (2 * i), "%02X", bytes[i]);
     }
 
+
+
     return hex_string;
 }
 
-- 
1.8.3.1