commit 0efa7592e3fb2ae647518a82ab19679b7c933d99
author David Benjamin <davidben@google.com> Fri Jan 27 20:51:33 2017 -0500
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Thu Feb 02 17:49:44 2017 +0000
tree 98741f786802d19c5a3554c7fbfc08daf367d444
parent e79fe70be9b2fa2fdab00456c48f04783236fbe5

dispatch_alert is not an incidental write.

It is impossible to have to call dispatch_alert when writing application
data. Now that we don't send warning alerts through ssl3_send_alert, all
alerts are closure alerts, which means attempts to write will fail.

This prunes a lot of dead code, avoiding the re-entrancy in the write
path. With that gone, tracking alert_dispatch is much more
straightforward.

BUG=146

Change-Id: Ie5fe677daee71e463d79562f3d2cea822a92581d
Reviewed-on: https://boringssl-review.googlesource.com/13500
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

ssl/d1_pkt.c

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index c6950d5..31d9dc0 100644
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -364,15 +364,6 @@
    * |ssl_write_buffer_flush|. */
   assert(!ssl_write_buffer_is_pending(ssl));
 
-  /* If we have an alert to send, lets send it */
-  if (ssl->s3->alert_dispatch) {
-    int ret = ssl->method->dispatch_alert(ssl);
-    if (ret <= 0) {
-      return ret;
-    }
-    /* if it went, fall through and send more stuff */
-  }
-
   if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
     return -1;
@@ -397,13 +388,12 @@
 }
 
 int dtls1_dispatch_alert(SSL *ssl) {
-  ssl->s3->alert_dispatch = 0;
   int ret = dtls1_write_record(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2,
                                dtls1_use_current_epoch);
   if (ret <= 0) {
-    ssl->s3->alert_dispatch = 1;
     return ret;
   }
+  ssl->s3->alert_dispatch = 0;
 
   /* If the alert is fatal, flush the BIO now. */
   if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) {

ssl/s3_pkt.c

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index d7402fc..84f52b5 100644
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -275,15 +275,6 @@
     return -1;
   }
 
-  /* If we have an alert to send, lets send it */
-  if (ssl->s3->alert_dispatch) {
-    int ret = ssl->method->dispatch_alert(ssl);
-    if (ret <= 0) {
-      return ret;
-    }
-    /* if it went, fall through and send more stuff */
-  }
-
   if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
     return -1;
@@ -464,10 +455,11 @@
     return -1;
   }
 
-  if (level == SSL3_AL_FATAL) {
-    ssl->s3->send_shutdown = ssl_shutdown_fatal_alert;
-  } else if (level == SSL3_AL_WARNING && desc == SSL_AD_CLOSE_NOTIFY) {
+  if (level == SSL3_AL_WARNING && desc == SSL_AD_CLOSE_NOTIFY) {
     ssl->s3->send_shutdown = ssl_shutdown_close_notify;
+  } else {
+    assert(level == SSL3_AL_FATAL);
+    ssl->s3->send_shutdown = ssl_shutdown_fatal_alert;
   }
 
   ssl->s3->alert_dispatch = 1;
@@ -484,12 +476,11 @@
 }
 
 int ssl3_dispatch_alert(SSL *ssl) {
-  ssl->s3->alert_dispatch = 0;
   int ret = do_ssl3_write(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2);
   if (ret <= 0) {
-    ssl->s3->alert_dispatch = 1;
     return ret;
   }
+  ssl->s3->alert_dispatch = 0;
 
   /* If the alert is fatal, flush the BIO now. */
   if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) {