commit 042e9427c38fb44f9addcbaf79455809c94b9b53
author Luke Huang <huangluke@google.com> Wed Feb 13 14:05:02 2019 +0800
committer Luke Huang <huangluke@google.com> Fri Feb 15 15:31:08 2019 +0800
tree 719200787c747a3aae0a342ff2b8d36e6be5225b
parent df34972b6b4c01046c4d480f7d2e07ec149a2144

Replace res_randomid with arc4random_uniform

Test: built, flashed, booted
      system/netd/tests/runtests.sh pass

Change-Id: Ie1f007f581c7e8becb429c0d27fd1c1b3a3f285e

resolv/res_init.cpp

diff --git a/resolv/res_init.cpp b/resolv/res_init.cpp
index eeafb0c..26cb9f3 100644
--- a/resolv/res_init.cpp
+++ b/resolv/res_init.cpp
@@ -144,7 +144,7 @@
         statp->retrans = RES_TIMEOUT;
         statp->retry = RES_DFLRETRY;
         statp->options = RES_DEFAULT;
-        statp->id = res_randomid();
+        statp->id = arc4random_uniform(65536);
         statp->_mark = MARK_UNSET;
     }
 

resolv/res_mkquery.cpp

diff --git a/resolv/res_mkquery.cpp b/resolv/res_mkquery.cpp
index 32c413f..b2f97c7 100644
--- a/resolv/res_mkquery.cpp
+++ b/resolv/res_mkquery.cpp
@@ -125,7 +125,7 @@
     if ((buf == NULL) || (buflen < HFIXEDSZ)) return (-1);
     memset(buf, 0, HFIXEDSZ);
     hp = (HEADER*) (void*) buf;
-    hp->id = htons(res_randomid());
+    hp->id = htons(arc4random_uniform(65536));
     hp->opcode = op;
     hp->rd = (statp->options & RES_RECURSE) != 0U;
     hp->ad = (statp->options & RES_USE_DNSSEC) != 0U;

resolv/res_send.cpp

diff --git a/resolv/res_send.cpp b/resolv/res_send.cpp
index 906269f..06cdb5b 100644
--- a/resolv/res_send.cpp
+++ b/resolv/res_send.cpp
@@ -251,7 +251,7 @@
     /* first try to bind to a random source port a few times */
     for (j = 0; j < 10; j++) {
         /* find a random port between 1025 .. 65534 */
-        int port = 1025 + (res_randomid() % (65535 - 1025));
+        int port = 1025 + (arc4random_uniform(65535 - 1025));
         if (family == AF_INET)
             u.sin.sin_port = htons(port);
         else

resolv/resolv_private.h

diff --git a/resolv/resolv_private.h b/resolv/resolv_private.h
index 3dfb999..d4b38be 100644
--- a/resolv/resolv_private.h
+++ b/resolv/resolv_private.h
@@ -250,8 +250,6 @@
 struct android_net_context; /* forward */
 void res_setnetcontext(res_state, const struct android_net_context*);
 
-u_int res_randomid(void);
-
 int getaddrinfo_numeric(const char* hostname, const char* servname, addrinfo hints,
                         addrinfo** result);