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.
28 /* Do this on our own in TRANSFER_BUF_SIZE chunks.
29 * It's safe to make direct syscalls to lseek/write here
30 * as we're below the Samba vfs layer.
32 * If tofd is -1 we just drain the incoming socket of count
33 * bytes without writing to the outgoing fd.
34 * If a write fails we do the same (to cope with disk full)
37 * Returns -1 on short reads from fromfd (read error)
40 * Returns number of bytes written to 'tofd'
41 * or thrown away if 'tofd == -1'.
42 * return != count then sets errno.
43 * Returns count if complete success.
46 #ifndef TRANSFER_BUF_SIZE
47 #define TRANSFER_BUF_SIZE (128*1024)
50 static ssize_t default_sys_recvfile(int fromfd,
57 size_t bufsize = MIN(TRANSFER_BUF_SIZE,count);
58 size_t total_written = 0;
61 DEBUG(10,("default_sys_recvfile: from = %d, to = %d, "
62 "offset=%.0f, count = %lu\n",
63 fromfd, tofd, (double)offset,
64 (unsigned long)count));
70 if (tofd != -1 && offset != (SMB_OFF_T)-1) {
71 if (sys_lseek(tofd, offset, SEEK_SET) == -1) {
72 if (errno != ESPIPE) {
78 buffer = SMB_MALLOC_ARRAY(char, bufsize);
83 while (total < count) {
84 size_t num_written = 0;
86 size_t toread = MIN(bufsize,count - total);
88 /* Read from socket - ignore EINTR. */
89 read_ret = sys_read(fromfd, buffer, toread);
91 /* EOF or socket error. */
98 while (num_written < read_ret) {
102 write_ret = read_ret;
104 /* Write to file - ignore EINTR. */
105 write_ret = sys_write(tofd,
106 buffer + num_written,
107 read_ret - num_written);
109 if (write_ret <= 0) {
110 /* write error - stop writing. */
117 num_written += (size_t)write_ret;
118 total_written += (size_t)write_ret;
126 /* Return the correct write error. */
129 return (ssize_t)total_written;
132 #if defined(HAVE_LINUX_SPLICE)
135 * Try and use the Linux system call to do this.
136 * Remember we only return -1 if the socket read
137 * failed. Else we return the number of bytes
138 * actually written. We always read count bytes
139 * from the network in the case of return != -1.
143 ssize_t sys_recvfile(int fromfd,
148 static int pipefd[2] = { -1, -1 };
149 static bool try_splice_call = false;
150 size_t total_written = 0;
151 loff_t splice_offset = offset;
153 DEBUG(10,("sys_recvfile: from = %d, to = %d, "
154 "offset=%.0f, count = %lu\n",
155 fromfd, tofd, (double)offset,
156 (unsigned long)count));
163 * Older Linux kernels have splice for sendfile,
164 * but it fails for recvfile. Ensure we only try
165 * this once and always fall back to the userspace
166 * implementation if recvfile splice fails. JRA.
169 if (!try_splice_call) {
170 return default_sys_recvfile(fromfd,
176 if ((pipefd[0] == -1) && (pipe(pipefd) == -1)) {
177 try_splice_call = false;
178 return default_sys_recvfile(fromfd, tofd, offset, count);
184 nread = splice(fromfd, NULL, pipefd[1], NULL,
185 MIN(count, 16384), SPLICE_F_MOVE);
187 if (errno == EINTR) {
190 if (total_written == 0 &&
191 (errno == EBADF || errno == EINVAL)) {
192 try_splice_call = false;
193 return default_sys_recvfile(fromfd, tofd,
200 while (to_write > 0) {
202 thistime = splice(pipefd[0], NULL, tofd,
203 &splice_offset, to_write,
205 if (thistime == -1) {
208 to_write -= thistime;
211 total_written += nread;
216 if (total_written < count) {
217 int saved_errno = errno;
218 if (drain_socket(fromfd, count-total_written) !=
219 count-total_written) {
220 /* socket is dead. */
226 return total_written;
230 /*****************************************************************
231 No recvfile system call - use the default 128 chunk implementation.
232 *****************************************************************/
234 ssize_t sys_recvfile(int fromfd,
239 return default_sys_recvfile(fromfd, tofd, offset, count);
243 /*****************************************************************
244 Throw away "count" bytes from the client socket.
245 *****************************************************************/
247 ssize_t drain_socket(int sockfd, size_t count)
249 return default_sys_recvfile(sockfd, -1, (SMB_OFF_T)-1, count);