From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Sat, 30 Nov 2019 17:39:25 +0000 (+0000)
Subject: FreeBSD: fix sendfile shim
X-Git-Tag: exim-4.93-RC6~1
X-Git-Url: https://vcs.fsf.org/?a=commitdiff_plain;h=1bf08084e235d22625eb78f457d668064a1ce28b;p=exim.git

FreeBSD: fix sendfile shim

Broken-by: 7d758a6a68
---

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 64198944a..8a0b75ede 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -213,6 +213,10 @@ JH/45 local_scan API: documented the current smtp_printf() call. This changed
       adjustment for any calls to smtp_printf() to match the new function
       signature; a FALSE value for the new argument is always safe.
 
+JH/46 FreeBSD: fix use of the sendfile() syscall.  The shim was not updating
+      the file-offset (which the Linux syscall does, and exim expects); this
+      resulted in an indefinite loop.
+
 
 Exim version 4.92
 -----------------
diff --git a/src/OS/os.c-FreeBSD b/src/OS/os.c-FreeBSD
index 1261b8557..4cc46c752 100644
--- a/src/OS/os.c-FreeBSD
+++ b/src/OS/os.c-FreeBSD
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) Jeremy Harris 1995 - 2018 */
+/* Copyright (c) Jeremy Harris 1995 - 2019 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* FreeBSD-specific code. This is concatenated onto the generic
@@ -14,11 +14,13 @@ src/os.c file. */
 *************/
 
 ssize_t
-os_sendfile(int out, int in, off_t * off, size_t cnt)
+os_sendfile(int out, int in, off_t * offp, size_t cnt)
 {
-off_t written;
-return sendfile(in, out, *off, cnt, NULL, &written, 0) < 0
-  ? (ssize_t) -1 : (ssize_t) written;
+off_t loff = *offp, written;
+
+if (sendfile(in, out, loff, cnt, NULL, &written, 0) < 0) return (ssize_t)-1;
+*offp = loff + written;
+return (ssize_t)written;
 }
 
 /* End of os.c-Linux */