From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Thu, 27 Nov 2025 11:00:11 +0000 (+0100)
Subject: dnsdist: Get rid of our own `random` code and use `dns_random`
X-Git-Tag: rec-5.4.0-alpha1~48^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d1644e321c4f3f9f075305b973dee8d0954a4974;p=thirdparty%2Fpdns.git

dnsdist: Get rid of our own `random` code and use `dns_random`

We introduced that code because the `dns_random` version that existed
at the time was pulling in a lot of code we did not want (logging,
configuration parsing, etc), but that no longer makes sense.

Signed-off-by: Remi Gacogne <remi.gacogne@powerdns.com>
---

diff --git a/pdns/dnsdistdist/dnsdist-random.cc b/pdns/dnsdistdist/dnsdist-random.cc
index 01e3ba4d9c..a99b0958e6 100644
--- a/pdns/dnsdistdist/dnsdist-random.cc
+++ b/pdns/dnsdistdist/dnsdist-random.cc
@@ -21,105 +21,23 @@
  */
 #include "config.h"
 
-#include <stdexcept>
-#include <sys/time.h>
-#include <unistd.h>
-#ifdef HAVE_LIBSODIUM
-#include <sodium.h>
-#endif /* HAVE_LIBSODIUM */
-#ifdef HAVE_RAND_BYTES
-#include <openssl/rand.h>
-#endif /* HAVE_RAND_BYTES */
-
-#if defined(HAVE_GETRANDOM)
-#include <sys/random.h>
-#endif
-
 #include "dnsdist-random.hh"
 #include "dns_random.hh"
-#include "dolog.hh"
-#include "misc.hh"
 
 namespace dnsdist
 {
-#if !defined(HAVE_LIBSODIUM) && defined(HAVE_GETRANDOM)
-static bool s_useGetRandom{true};
-#endif
-
 void initRandom()
 {
-#ifdef HAVE_LIBSODIUM
-  srandom(randombytes_random());
-#else
-  {
-    auto getSeed = []() {
-#if defined(HAVE_GETRANDOM)
-      char buf[1];
-      // some systems define getrandom but it does not really work, e.g. because it's
-      // not present in kernel.
-      if (getrandom(buf, sizeof(buf), 0) == -1 && errno != EINTR) {
-        warnlog("getrandom() failed %s", stringerror());
-        s_useGetRandom = false;
-      }
-#endif /* HAVE_GETRANDOM */
-#ifdef HAVE_RAND_BYTES
-      unsigned int seed;
-      if (RAND_bytes(reinterpret_cast<unsigned char*>(&seed), sizeof(seed)) == 1) {
-        return seed;
-      }
-#endif /* HAVE_RAND_BYTES */
-      struct timeval tv;
-      gettimeofday(&tv, 0);
-      return static_cast<unsigned int>(tv.tv_sec ^ tv.tv_usec ^ getpid());
-    };
-
-    srandom(getSeed());
-  }
-#endif
+  srandom(dns_random_uint32());
 }
 
 uint32_t getRandomValue(uint32_t upperBound)
 {
-#ifdef HAVE_LIBSODIUM
-  return randombytes_uniform(upperBound);
-#else /* HAVE_LIBSODIUM */
-  uint32_t result = 0;
-  unsigned int min = pdns::random_minimum_acceptable_value(upperBound);
-
-#if defined(HAVE_GETRANDOM)
-  if (s_useGetRandom) {
-    do {
-      auto got = getrandom(&result, sizeof(result), 0);
-      if (got == -1 && errno == EINTR) {
-        continue;
-      }
-      if (got != sizeof(result)) {
-        throw std::runtime_error("Error getting a random value via getrandom(): " + stringerror());
-      }
-    } while (result < min);
-
-    return result % upperBound;
-  }
-#endif /* HAVE_GETRANDOM */
-#ifdef HAVE_RAND_BYTES
-  do {
-    if (RAND_bytes(reinterpret_cast<unsigned char*>(&result), sizeof(result)) != 1) {
-      throw std::runtime_error("Error getting a random value via RAND_bytes");
-    }
-  } while (result < min);
-
-  return result % upperBound;
-#endif /* HAVE_RAND_BYTES */
-  do {
-    result = random();
-  } while (result < min);
-
-  return result % upperBound;
-#endif /* HAVE_LIBSODIUM */
+  return dns_random(upperBound);
 }
 
 uint16_t getRandomDNSID()
 {
-  return getRandomValue(65536);
+  return dns_random_uint16();
 }
 }