Forgot to add recvfile.c
authorJeremy Allison <jra@samba.org>
Tue, 30 Oct 2007 00:17:16 +0000 (17:17 -0700)
committerJeremy Allison <jra@samba.org>
Tue, 30 Oct 2007 00:17:16 +0000 (17:17 -0700)
Jeremy.
(This used to be commit d5886218e53910b7015e6f13bc634e1bf338565a)

source3/lib/recvfile.c [new file with mode: 0644]

diff --git a/source3/lib/recvfile.c b/source3/lib/recvfile.c
new file mode 100644 (file)
index 0000000..cd9fb12
--- /dev/null
@@ -0,0 +1,158 @@
+/*
+ Unix SMB/Netbios implementation.
+ Version 3.2.x
+ recvfile implementations.
+ Copyright (C) Jeremy Allison 2007.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ * This file handles the OS dependent recvfile implementations.
+ * The API is such that it returns -1 on error, else returns the
+ * number of bytes written.
+ */
+
+#include "includes.h"
+
+/* Do this on our own in TRANSFER_BUF_SIZE chunks.
+ * It's safe to make direct syscalls to lseek/write here
+ * as we're below the Samba vfs layer.
+ *
+ * If tofd is -1 we just drain the incoming socket of count
+ * bytes without writing to the outgoing fd.
+ * If a write fails we do the same (to cope with disk full)
+ * errors.
+ *
+ * Returns -1 on short reads from fromfd (read error)
+ * and sets errno.
+ *
+ * Returns number of bytes written to 'tofd'
+ * or thrown away if 'tofd == -1'.
+ * eturn != count then sets errno.
+ * Returns count if complete success.
+ */
+
+#ifndef TRANSFER_BUF_SIZE
+#define TRANSFER_BUF_SIZE (128*1024)
+#endif
+
+static ssize_t default_sys_recvfile(int fromfd,
+                       int tofd,
+                       SMB_OFF_T offset,
+                       size_t count)
+{
+       int saved_errno = 0;
+       size_t total = 0;
+       size_t bufsize = MIN(TRANSFER_BUF_SIZE,count);
+       size_t total_written = 0;
+       char *buffer = NULL;
+
+       if (count == 0) {
+               return 0;
+       }
+
+       if (tofd != -1 && offset != (SMB_OFF_T)-1) {
+               if (sys_lseek(tofd, offset, SEEK_SET) == -1) {
+                       if (errno != ESPIPE) {
+                               return -1;
+                       }
+               }
+       }
+
+       buffer = SMB_MALLOC_ARRAY(char, bufsize);
+       if (buffer == NULL) {
+               return -1;
+       }
+
+       while (total < count) {
+               size_t num_written = 0;
+               ssize_t read_ret;
+               size_t toread = MIN(bufsize,count - total);
+
+               /* Read from socket - ignore EINTR. */
+               read_ret = sys_read(fromfd, buffer, toread);
+               if (read_ret <= 0) {
+                       /* EOF or socket error. */
+                       free(buffer);
+                       return -1;
+               }
+
+               num_written = 0;
+
+               while (num_written < read_ret) {
+                       ssize_t write_ret;
+
+                       if (tofd == -1) {
+                               write_ret = read_ret;
+                       } else {
+                               /* Write to file - ignore EINTR. */
+                               write_ret = sys_write(tofd,
+                                               buffer + num_written,
+                                               read_ret - num_written);
+
+                               if (write_ret <= 0) {
+                                       /* write error - stop writing. */
+                                       tofd = -1;
+                                       saved_errno = errno;
+                                       continue;
+                               }
+                       }
+
+                       num_written += (size_t)write_ret;
+                       total_written += (size_t)write_ret;
+               }
+
+               total += read_ret;
+       }
+
+       free(buffer);
+       if (saved_errno) {
+               /* Return the correct write error. */
+               errno = saved_errno;
+       }
+       return (ssize_t)total_written;
+}
+
+#if defined(HAVE_SPLICE_SYSCALL)
+ssize_t sys_recvfile(int fromfd,
+                       int tofd,
+                       SMB_OFF_T offset,
+                       size_t count)
+{
+       errno = ENOSYS
+       return -1;
+}
+#else
+
+/*****************************************************************
+ No recvfile system call - use the default 128 chunk implementation.
+*****************************************************************/
+
+ssize_t sys_recvfile(int fromfd,
+                       int tofd,
+                       SMB_OFF_T offset,
+                       size_t count)
+{
+       return default_sys_recvfile(fromfd, tofd, offset, count);
+}
+#endif
+
+/*****************************************************************
+ Throw away "count" bytes from the client socket.
+*****************************************************************/
+
+ssize_t drain_socket(int sockfd, size_t count)
+{
+       return default_sys_recvfile(sockfd, -1, (SMB_OFF_T)-1, count);
+}