debian/patches/80_02-GnuTLS-tls_write-wait-after-uncorking-the-session.patch

   1 From 783cb0301d9ceef2748956c3f91762275b7b45e5 Mon Sep 17 00:00:00 2001
   2 From: "Heiko Schlittermann (HS12-RIPE)" <hs@schlittermann.de>
   3 Date: Tue, 18 Feb 2020 18:59:49 +0100
   4 Subject: [PATCH 5/6] GnuTLS: tls_write(): wait after uncorking the session
   5
   6 (cherry picked from commit 8f9adfd36222d4e9e730734e00dffe874073e5b4)
   7 ---
   8  src/tls-gnu.c | 34 ++++++++++++++++++++++++++++------
   9  1 file changed, 28 insertions(+), 6 deletions(-)
  10
  11 diff --git a/src/tls-gnu.c b/src/tls-gnu.c
  12 index 822ad89c6..94a718673 100644
  13 --- a/src/tls-gnu.c
  14 +++ b/src/tls-gnu.c
  15 @@ -2835,9 +2835,14 @@ tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more)
  16  ssize_t outbytes;
  17  size_t left = len;
  18  exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server;
  19 -#ifdef SUPPORT_CORK
  20
  21 -if (more && !state->corked) gnutls_record_cork(state->session);
  22 +#ifdef SUPPORT_CORK
  23 +if (more && !state->corked)
  24 +  {
  25 +  DEBUG(D_tls) debug_printf("gnutls_record_cork(session=%p)\n", state->session);
  26 +  gnutls_record_cork(state->session);
  27 +  state->corked = TRUE;
  28 +  }
  29  #endif
  30
  31  DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__,
  32 @@ -2853,6 +2858,7 @@ while (left > 0)
  33    while (outbytes == GNUTLS_E_AGAIN);
  34
  35    DEBUG(D_tls) debug_printf("outbytes=" SSIZE_T_FMT "\n", outbytes);
  36 +
  37    if (outbytes < 0)
  38      {
  39      DEBUG(D_tls) debug_printf("%s: gnutls_record_send err\n", __FUNCTION__);
  40 @@ -2878,10 +2884,26 @@ if (len > INT_MAX)
  41    }
  42
  43  #ifdef SUPPORT_CORK
  44 -if (more != state->corked)
  45 -  {
  46 -  if (!more) (void) gnutls_record_uncork(state->session, 0);
  47 -  state->corked = more;
  48 +if (!more && state->corked)
  49 +  {
  50 +  DEBUG(D_tls) debug_printf("gnutls_record_uncork(session=%p)\n", state->session);
  51 +  do {
  52 +    do
  53 +      /* We can't use GNUTLS_RECORD_WAIT here, as it retries on
  54 +      GNUTLS_E_AGAIN || GNUTLS_E_INTR, which would break our timeout set by alarm().
  55 +      The GNUTLS_E_AGAIN should not happen ever, as our sockets are blocking anyway.
  56 +      But who knows. (That all relies on the fact that GNUTLS_E_INTR and GNUTLS_E_AGAIN
  57 +      match the EINTR and EAGAIN errno values.) */
  58 +      outbytes = gnutls_record_uncork(state->session, 0);
  59 +    while (outbytes == GNUTLS_E_AGAIN);
  60 +
  61 +     if (outbytes < 0)
  62 +       {
  63 +       record_io_error(state, len, US"uncork", NULL);
  64 +       return -1;
  65 +       }
  66 +  } while (gnutls_record_check_corked(state->session) > 0);
  67 +  state->corked = FALSE;
  68    }
  69  #endif
  70
  71 --
  72 2.28.0
  73