2 Unix SMB/Netbios implementation.
4 recvfile implementations.
5 Copyright (C) Jeremy Allison 2007.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, see <http://www.gnu.org/licenses/>.
21 * This file handles the OS dependent recvfile implementations.
22 * The API is such that it returns -1 on error, else returns the
23 * number of bytes written.
27 #include "system/filesys.h"
29 /* Do this on our own in TRANSFER_BUF_SIZE chunks.
30 * It's safe to make direct syscalls to lseek/write here
31 * as we're below the Samba vfs layer.
33 * Returns -1 on short reads from fromfd (read error)
36 * Returns number of bytes written to 'tofd'
37 * return != count then sets errno.
38 * Returns count if complete success.
41 #ifndef TRANSFER_BUF_SIZE
42 #define TRANSFER_BUF_SIZE (128*1024)
45 static ssize_t default_sys_recvfile(int fromfd,
52 size_t bufsize = MIN(TRANSFER_BUF_SIZE,count);
53 size_t total_written = 0;
56 DEBUG(10,("default_sys_recvfile: from = %d, to = %d, "
57 "offset=%.0f, count = %lu\n",
58 fromfd, tofd, (double)offset,
59 (unsigned long)count));
65 if (tofd != -1 && offset != (off_t)-1) {
66 if (lseek(tofd, offset, SEEK_SET) == -1) {
67 if (errno != ESPIPE) {
73 buffer = SMB_MALLOC_ARRAY(char, bufsize);
78 while (total < count) {
79 size_t num_written = 0;
81 size_t toread = MIN(bufsize,count - total);
83 /* Read from socket - ignore EINTR. */
84 read_ret = sys_read(fromfd, buffer, toread);
86 /* EOF or socket error. */
93 /* Don't write any more after a write error. */
94 while (tofd != -1 && (num_written < read_ret)) {
97 /* Write to file - ignore EINTR. */
98 write_ret = sys_write(tofd,
100 read_ret - num_written);
102 if (write_ret <= 0) {
103 /* write error - stop writing. */
105 if (total_written == 0) {
115 num_written += (size_t)write_ret;
116 total_written += (size_t)write_ret;
124 /* Return the correct write error. */
127 return (ssize_t)total_written;
130 #if defined(HAVE_LINUX_SPLICE)
133 * Try and use the Linux system call to do this.
134 * Remember we only return -1 if the socket read
135 * failed. Else we return the number of bytes
136 * actually written. We always read count bytes
137 * from the network in the case of return != -1.
141 ssize_t sys_recvfile(int fromfd,
146 static int pipefd[2] = { -1, -1 };
147 static bool try_splice_call = false;
148 size_t total_written = 0;
149 loff_t splice_offset = offset;
151 DEBUG(10,("sys_recvfile: from = %d, to = %d, "
152 "offset=%.0f, count = %lu\n",
153 fromfd, tofd, (double)offset,
154 (unsigned long)count));
161 * Older Linux kernels have splice for sendfile,
162 * but it fails for recvfile. Ensure we only try
163 * this once and always fall back to the userspace
164 * implementation if recvfile splice fails. JRA.
167 if (!try_splice_call) {
168 return default_sys_recvfile(fromfd,
174 if ((pipefd[0] == -1) && (pipe(pipefd) == -1)) {
175 try_splice_call = false;
176 return default_sys_recvfile(fromfd, tofd, offset, count);
182 nread = splice(fromfd, NULL, pipefd[1], NULL,
183 MIN(count, 16384), SPLICE_F_MOVE);
185 if (errno == EINTR) {
188 if (total_written == 0 &&
189 (errno == EBADF || errno == EINVAL)) {
190 try_splice_call = false;
191 return default_sys_recvfile(fromfd, tofd,
198 while (to_write > 0) {
200 thistime = splice(pipefd[0], NULL, tofd,
201 &splice_offset, to_write,
203 if (thistime == -1) {
206 to_write -= thistime;
209 total_written += nread;
215 int saved_errno = errno;
216 if (drain_socket(fromfd, count) != count) {
217 /* socket is dead. */
223 return total_written;
227 /*****************************************************************
228 No recvfile system call - use the default 128 chunk implementation.
229 *****************************************************************/
231 ssize_t sys_recvfile(int fromfd,
236 return default_sys_recvfile(fromfd, tofd, offset, count);
240 /*****************************************************************
241 Throw away "count" bytes from the client socket.
242 Returns count or -1 on error.
243 Must only operate on a blocking socket.
244 *****************************************************************/
246 ssize_t drain_socket(int sockfd, size_t count)
249 size_t bufsize = MIN(TRANSFER_BUF_SIZE,count);
257 buffer = SMB_MALLOC_ARRAY(char, bufsize);
258 if (buffer == NULL) {
262 old_flags = fcntl(sockfd, F_GETFL, 0);
263 if (set_blocking(sockfd, true) == -1) {
268 while (total < count) {
270 size_t toread = MIN(bufsize,count - total);
272 /* Read from socket - ignore EINTR. */
273 read_ret = sys_read(sockfd, buffer, toread);
275 /* EOF or socket error. */
285 if (fcntl(sockfd, F_SETFL, old_flags) == -1) {