fc_srand rename to fc_safe_srand and fc_rand rename to fc_safe_rand

HISTORY

@@ -1,4 +1,7 @@
 
+Version 1.85  2026-06-08
+  * add functions fc_safe_srand and fc_safe_rand for more security under Linux
+
 Version 1.84  2026-01-16
   * fast_task_queue.h: add function free_queue_task_arg_offset
   * add function double2str and double_to_comma_str

src/fast_allocator.c

@@ -238,7 +238,7 @@ int fast_allocator_init_ex(struct fast_allocator_context *acontext,
 	struct fast_region_info *pRegion;
 	struct fast_region_info *region_end;
 
-	srand(time(NULL));
+	set_rand_seed();
 	memset(acontext, 0, sizeof(*acontext));
 	if (region_count <= 0)
 	{

src/flat_skiplist.c

@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <assert.h>
 #include "logger.h"
+#include "shared_func.h"
 #include "fc_memory.h"
 #include "flat_skiplist.h"
 
@@ -111,7 +112,7 @@ int flat_skiplist_init_ex(FlatSkiplist *sl, const int level_count,
     sl->compare_func = compare_func;
     sl->free_func = free_func;
 
-    srand(time(NULL));
+    set_rand_seed();
     return 0;
 }
 

src/multi_skiplist.c

@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <assert.h>
 #include "logger.h"
+#include "shared_func.h"
 #include "fc_memory.h"
 #include "multi_skiplist.h"
 
@@ -118,7 +119,7 @@ int multi_skiplist_init_ex(MultiSkiplist *sl, const int level_count,
     sl->compare_func = compare_func;
     sl->free_func = free_func;
 
-    srand(time(NULL));
+    set_rand_seed();
     return 0;
 }
 

src/shared_func.c

@@ -2486,19 +2486,15 @@ int parse_bytes(const char *pStr, const int default_unit_bytes, int64_t *bytes)
 
 int set_rand_seed()
 {
-	struct timeval tv;
+    time_t ts;
+    int64_t ns;
+    uint32_t seed;
 
-	if (gettimeofday(&tv, NULL) != 0)
-	{
-		logError("file: "__FILE__", line: %d, " \
-			 "call gettimeofday fail, " \
-			 "errno=%d, error info: %s", \
-			 __LINE__, errno, STRERROR(errno));
-		return errno != 0 ? errno : EPERM;
-	}
-
-	srand(tv.tv_sec ^ tv.tv_usec);
-	return 0;
+    ns = get_current_time_ns();
+    time(&ts);
+    seed = ts ^ (ns & 0xFFFFFFFF);
+    srand(seed);
+    return 0;
 }
 
 int get_time_item_from_conf_ex(IniFullContext *ini_ctx,
@@ -4555,3 +4551,32 @@ const char *double2str(const double d, const int scale,
     memcpy(buff + new_len, fragment, tail_len + 1);
     return buff;
 }
+
+#ifdef OS_LINUX
+
+#ifndef __NR_getrandom
+#define __NR_getrandom 318
+#endif
+
+void fc_safe_srand()
+{
+    uint32_t seed;
+
+    if (syscall(__NR_getrandom, &seed, sizeof(seed), 0) != sizeof(seed)) {
+        set_rand_seed();
+    } else {
+        srand(seed);
+    }
+}
+
+int fc_safe_rand()
+{
+    uint32_t n;
+
+    if (syscall(__NR_getrandom, &n, sizeof(n), 0) != sizeof(n)) {
+        return rand();
+    }
+
+    return (n & RAND_MAX);
+}
+#endif

src/shared_func.h

@@ -1867,6 +1867,14 @@ static inline size_t fc_iov_get_bytes(const
     }
 }
 
+#ifdef OS_LINUX
+void fc_safe_srand();
+int fc_safe_rand();
+#else
+#define fc_safe_srand() set_rand_seed()
+#define fc_safe_rand() rand()
+#endif
+
 #ifdef __cplusplus
 }
 #endif

src/skiplist_set.c

@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <assert.h>
 #include "logger.h"
+#include "shared_func.h"
 #include "fc_memory.h"
 #include "skiplist_set.h"
 
@@ -110,7 +111,7 @@ int skiplist_set_init_ex(SkiplistSet *sl, const int level_count,
     sl->compare_func = compare_func;
     sl->free_func = free_func;
 
-    srand(time(NULL));
+    set_rand_seed();
     return 0;
 }
 

src/uniq_skiplist.c

@@ -21,6 +21,7 @@
 #include <string.h>
 #include <errno.h>
 #include "logger.h"
+#include "shared_func.h"
 #include "fc_memory.h"
 #include "uniq_skiplist.h"
 
@@ -138,7 +139,7 @@ int uniq_skiplist_init_ex2(UniqSkiplistFactory *factory,
     factory->delay_free_seconds = delay_free_seconds;
     factory->arg = arg;
 
-    srand(time(NULL));
+    set_rand_seed();
     return 0;
 }