Use libent for getentropy

.gitmodules

@@ -7,6 +7,9 @@
 [submodule "subprojects/h2o"]
 	path = subprojects/libh2o
 	url = https://github.com/urbit/h2o.git
+[submodule "subprojects/libent"]
+	path = subprojects/libent
+	url = https://github.com/urbit/libent.git
 [submodule "subprojects/libuv"]
 	path = subprojects/libuv
 	url = https://github.com/urbit/libuv.git

include/c/portable.h

@@ -183,17 +183,6 @@
 #       define lseek64 lseek
 #     else
 #       error "port: timeconvert"
-#     endif
-
-    /* Entropy.
-    */
-#     if defined(U3_OS_linux)
-#       define c3_getentropy(B, L) \
-          ((L) == syscall(SYS_getrandom, B, L, 0) ? 0 : -1)
-#     elif defined(U3_OS_bsd) || defined(U3_OS_osx)
-#       define c3_getentropy getentropy
-#     else
-#       error "port: getentropy"
 #     endif
 
     /* Static assertion.

meson.build

@@ -320,6 +320,7 @@ endif
 # For these libs we provide fallback bundle
 argon2_dep = dependency('argon2', version: '>=1', fallback: ['argon2', 'argon2_dep'])
 ed25519_dep = dependency('ed25519', version: '>=0.1.0', fallback: ['ed25519', 'ed25519_dep'])
+libent_dep = dependency('libent', version: '>=0.1.3', fallback: ['libent', 'libent_dep'])
 libh2o_dep = dependency('libh2o', version: '>=0.13.3', fallback: ['libh2o', 'libh2o_dep'])
 libscrypt_dep = dependency('libscrypt', version: '>=0.1.21', fallback: ['libscrypt', 'libscrypt_dep'])
 libsni_dep = dependency('libsni', version: '>=0.5.0', fallback: ['libsni', 'libsni_dep'])
@@ -332,6 +333,7 @@ deps = [argon2_dep,
         curl_dep,
         ed25519_dep,
         gmp_dep,
+        libent_dep,
         libh2o_dep,
         libscrypt_dep,
         libsni_dep,

subprojects/libent

@@ -0,0 +1 @@
+Subproject commit 7506fb31577fc5e185b31ed9f6ce6072e3f20637

vere/sist.c

@@ -1,6 +1,7 @@
 /* vere/sist.c
 **
 */
+#include <ent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <uv.h>
@@ -406,7 +407,7 @@ _sist_bask(c3_c* pop_c, u3_noun may)
 void
 c3_rand(c3_w* rad_w)
 {
-  if ( 0 != c3_getentropy(rad_w, 64) ) {
+  if ( 0 != ent_getentropy(rad_w, 64) ) {
     uL(fprintf(uH, "c3_rand getentropy: %s\n", strerror(errno)));
     u3_lo_bail();
   }