[network] add darwin-sendfile backend (fixes #2687)

The FreeBSD version of sendfile is already supported.  Starting
with OS X 10.5, Darwin also supports sendfile, but using a
slightly different argument list even though much of the
implementation is likely taken from FreeBSD just like the man
page is.

Add support for darwin's sendfile by introducing a new
network_darwin_sendfile.c file that's just a copy of the
network_freebsd_sendfile.c file except with the arguments
adjusted to compensate for the minor API difference (FreeBSD
has separate in and out byte count arguments whereas Darwin
has a combined in/out byte count argument).

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@3060 152afb58-edef-0310-8abb-c4023f1b3aa9

NEWS

@@ -18,6 +18,7 @@ NEWS
   * [core] encode path with ENCODING_REL_URI in redirect to directory (fixes #2661, thx gstrauss)
   * [mod_secdownload] add required algorithm option; old behaviour available as "md5", new options "hmac-sha1" and "hmac-sha256"
   * [mod_fastcgi/mod_scgi] zero sockaddr structs before use (fixes #2691, thx Kyle J. McKay)
+  * [network] add darwin-sendfile backend (fixes #2687, thx Kyle J. McKay)
 
 - 1.4.37 - 2015-08-30
   * [mod_proxy] remove debug log line from error log (fixes #2659)

src/CMakeLists.txt

@@ -494,7 +494,7 @@ set(COMMON_SRC
 	network_write.c network_linux_sendfile.c
 	network_freebsd_sendfile.c
 	network_solaris_sendfilev.c network_openssl.c
-	status_counter.c safe_memclear.c
+	status_counter.c safe_memclear.c network_darwin_sendfile.c
 )
 
 if(WIN32)

src/Makefile.am

@@ -76,7 +76,7 @@ common_src=base64.c buffer.c log.c \
 	network_freebsd_sendfile.c network_writev.c \
 	network_solaris_sendfilev.c network_openssl.c \
 	splaytree.c status_counter.c \
-	safe_memclear.c
+	safe_memclear.c network_darwin_sendfile.c
 
 src = server.c response.c connections.c network.c \
 	configfile.c configparser.c request.c proc_open.c

src/SConscript

@@ -28,7 +28,7 @@ common_src = Split("base64.c buffer.c log.c \
 	network_write.c network_linux_sendfile.c \
 	network_freebsd_sendfile.c  \
 	network_solaris_sendfilev.c network_openssl.c \
-	status_counter.c safe_memclear.c \
+	status_counter.c safe_memclear.c network_darwin_sendfile.c \
 ")
 
 src = Split("server.c response.c connections.c network.c \

src/network_backends.h

@@ -25,6 +25,14 @@
 # define USE_FREEBSD_SENDFILE
 #endif
 
+#if defined HAVE_SENDFILE && defined(__APPLE__)
+# ifdef USE_SENDFILE
+#  error "can't have more than one sendfile implementation"
+# endif
+# define USE_SENDFILE "darwin-sendfile"
+# define USE_DARWIN_SENDFILE
+#endif
+
 #if defined HAVE_SYS_SENDFILE_H && defined HAVE_SENDFILEV && defined(__sun)
 # ifdef USE_SENDFILE
 #  error "can't have more than one sendfile implementation"

src/network_darwin_sendfile.c

@@ -0,0 +1,61 @@
+#include "network_backends.h"
+
+#if defined(USE_DARWIN_SENDFILE)
+
+#include "network.h"
+#include "log.h"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+
+#include <errno.h>
+#include <string.h>
+
+int network_write_file_chunk_sendfile(server *srv, connection *con, int fd, chunkqueue *cq, off_t *p_max_bytes) {
+	chunk* const c = cq->first;
+	off_t offset, written = 0;
+	off_t toSend;
+	int r;
+
+	force_assert(NULL != c);
+	force_assert(FILE_CHUNK == c->type);
+	force_assert(c->offset >= 0 && c->offset <= c->file.length);
+
+	offset = c->file.start + c->offset;
+	toSend = c->file.length - c->offset;
+	if (toSend > *p_max_bytes) toSend = *p_max_bytes;
+
+	if (0 == toSend) {
+		chunkqueue_remove_finished_chunks(cq);
+		return 0;
+	}
+
+	if (0 != network_open_file_chunk(srv, con, cq)) return -1;
+
+	/* Darwin sendfile() */
+	written = toSend;
+	if (-1 == (r = sendfile(c->file.fd, fd, offset, &written, NULL, 0))) {
+		switch(errno) {
+		case EAGAIN:
+		case EINTR:
+			/* for EAGAIN/EINTR written still contains the sent bytes */
+			break; /* try again later */
+		case EPIPE:
+		case ENOTCONN:
+			return -2;
+		default:
+			log_error_write(srv, __FILE__, __LINE__, "ssd", "sendfile: ", strerror(errno), errno);
+			return -1;
+		}
+	}
+
+	if (written >= 0) {
+		chunkqueue_mark_written(cq, written);
+		*p_max_bytes -= written;
+	}
+
+	return (r >= 0 && written == toSend) ? 0 : -3;
+}
+
+#endif /* USE_DARWIN_SENDFILE */

src/server.c

@@ -422,6 +422,11 @@ static void show_features (void) {
 #else
       "\t- freebsd-sendfile\n"
 #endif
+#if defined USE_DARWIN_SENDFILE
+      "\t+ darwin-sendfile\n"
+#else
+      "\t- darwin-sendfile\n"
+#endif
 #if defined USE_SOLARIS_SENDFILEV
       "\t+ solaris-sendfilev\n"
 #else