Provide an idiomatic c++ interface for action lists

[lttng-tools.git] / src / common / random.cpp

diff --git a/src/common/random.cpp b/src/common/random.cpp
index b282d67d0157386c26e8343709865bf66145d817..26f51d3a4a0a674e19c3721b69ee5ad23eefa2b0 100644 (file)
--- a/src/common/random.cpp
+++ b/src/common/random.cpp
@@ -5,6 +5,7 @@
  *
  */
 
+#include <common/error.hpp>
 #include <common/file-descriptor.hpp>
 #include <common/format.hpp>
 #include <common/hashtable/utils.hpp>
@@ -71,10 +72,20 @@ void getrandom_nonblock(char *out_data, std::size_t size)
                        errno);
        }
 }
+#elif defined(HAVE_ARC4RANDOM)
+
+#include <stdlib.h>
+
+/*
+ * According to the MacOS / FreeBSD manpage, this function never fails nor blocks.
+ */
+void getrandom_nonblock(char *out_data, std::size_t size)
+{
+       arc4random_buf(out_data, size);
+}
 #else /* defined(__linux__) && defined(SYS_getrandom) && defined(HAVE_SYS_RANDOM_H) */
-__attribute__((noreturn))
-void getrandom_nonblock(char *out_data __attribute__((unused)),
-               std::size_t size __attribute__((unused)))
+__attribute__((noreturn)) void getrandom_nonblock(char *out_data __attribute__((unused)),
+                                                 std::size_t size __attribute__((unused)))
 {
        LTTNG_THROW_RANDOM_PRODUCTION_ERROR("getrandom() is not supported by this platform");
 }
@@ -138,11 +149,11 @@ lttng::random::seed_t produce_random_seed_from_urandom()
        }() };
 
        lttng::random::seed_t seed;
-       const auto read_ret = lttng_read(urandom.fd(), &seed, sizeof(seed));
-       if (read_ret != sizeof(seed)) {
-               LTTNG_THROW_POSIX(fmt::format("Failed to read from `/dev/urandom`: size={}",
-                                             sizeof(seed)),
-                                 errno);
+       try {
+               urandom.read(&seed, sizeof(seed));
+       } catch (const std::exception& e) {
+               LTTNG_THROW_RANDOM_PRODUCTION_ERROR(fmt::format(
+                       "Failed to read from `/dev/urandom`: size={}: {}", sizeof(seed), e.what()));
        }
 
        return seed;
@@ -170,7 +181,7 @@ lttng::random::seed_t lttng::random::produce_best_effort_random_seed()
 {
        try {
                return lttng::random::produce_true_random_seed();
-       } catch (std::exception& e) {
+       } catch (const std::exception& e) {
                WARN("%s",
                     fmt::format(
                             "Failed to produce a random seed using getrandom(), falling back to pseudo-random device seed generation which will block until its pool is initialized: {}",
@@ -184,7 +195,7 @@ lttng::random::seed_t lttng::random::produce_best_effort_random_seed()
                 * under some containerized environments.
                 */
                produce_random_seed_from_urandom();
-       } catch (std::exception& e) {
+       } catch (const std::exception& e) {
                WARN("%s",
                     fmt::format("Failed to produce a random seed from the urandom device: {}",
                                 e.what())