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-rw-r--r--source3/lib/recvfile.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/source3/lib/recvfile.c b/source3/lib/recvfile.c
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+++ b/source3/lib/recvfile.c
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+/*
+ 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);
+}