add random() to list of rand() fallbacks

(but prefer better mechanisms)

SConstruct

@@ -220,7 +220,7 @@ if 1:
 			getuid select signal pathconf madvise prctl\
 			writev sigaction sendfile64 send_file kqueue port_create localtime_r posix_fadvise issetugid inet_pton \
 			memset_s explicit_bzero clock_gettime \
-			getentropy arc4random jrand48'))
+			getentropy arc4random jrand48 srandom'))
 	checkFunc(autoconf, 'getrandom', 'linux/random.h')
 
 	checkTypes(autoconf, Split('pid_t size_t off_t'))

configure.ac

@@ -763,7 +763,7 @@ AC_CHECK_FUNCS([dup2 getcwd inet_ntoa inet_ntop inet_pton issetugid memset mmap
 		  getuid select signal pathconf madvise posix_fadvise posix_madvise \
 		  writev sigaction sendfile64 send_file kqueue port_create localtime_r gmtime_r \
 		  memset_s explicit_bzero clock_gettime \
-		  getentropy arc4random jrand48])
+		  getentropy arc4random jrand48 srandom])
 AC_CHECK_HEADERS([linux/random.h],[
   AC_CHECK_FUNC([getrandom], AC_DEFINE([HAVE_GETRANDOM], [1], [getrandom]))
 ])

src/CMakeLists.txt

@@ -159,6 +159,7 @@ check_function_exists(sendfilev HAVE_SENDFILEV)
 check_function_exists(sigaction HAVE_SIGACTION)
 check_function_exists(signal HAVE_SIGNAL)
 check_function_exists(sigtimedwait HAVE_SIGTIMEDWAIT)
+check_function_exists(srandom HAVE_SRANDOM)
 check_function_exists(strptime HAVE_STRPTIME)
 check_function_exists(syslog HAVE_SYSLOG)
 check_function_exists(writev HAVE_WRITEV)

src/rand.c

@@ -123,19 +123,24 @@ void li_rand_reseed (void)
     unsigned int u;
     if (1 == li_rand_device_bytes((unsigned char *)xsubi, (int)sizeof(xsubi))) {
         u = ((unsigned int)xsubi[0] << 16) | xsubi[1];
-        srand(u); /*(initialize just in case rand() used elsewhere)*/
     }
     else {
       #ifdef HAVE_ARC4RANDOM
-        srand(arc4random()); /*(initialize just in case rand() used elsewhere)*/
+        u = arc4random();
         arc4random_buf(xsubi, sizeof(xsubi));
       #else
         /* NOTE: not cryptographically random !!! */
         srand((unsigned int)(time(NULL) ^ getpid()));
         for (u = 0; u < sizeof(unsigned short); ++u)
+            /* coverity[dont_call : FALSE] */
             xsubi[u] = (unsigned short)(rand() & 0xFFFF);
+        u = ((unsigned int)xsubi[0] << 16) | xsubi[1];
       #endif
     }
+    srand(u);   /*(initialize just in case rand() used elsewhere)*/
+  #ifdef HAVE_SRANDOM
+    srandom(u); /*(initialize just in case random() used elsewhere)*/
+  #endif
   #ifdef USE_OPENSSL
     RAND_poll();
     RAND_seed(xsubi, (int)sizeof(xsubi));
@@ -152,11 +157,15 @@ int li_rand (void)
   #endif
   #ifdef HAVE_ARC4RANDOM
     return (int)arc4random();
-  #endif
-  #ifdef HAVE_JRAND48
+  #elif defined(HAVE_SRANDOM)
+    /* coverity[dont_call : FALSE] */
+    return (int)random();
+  #elif defined(HAVE_JRAND48)
     /*(FYI: jrand48() reentrant, but use of file-scoped static xsubi[] is not)*/
+    /* coverity[dont_call : FALSE] */
     return (int)jrand48(xsubi);
   #else
+    /* coverity[dont_call : FALSE] */
     return rand();
   #endif
 }