2 * Copyright (c) 1998 Adrian Sun (asun@zoology.washington.edu)
3 * All rights reserved. See COPYRIGHT.
5 * this file provides the following functions:
6 * dsi_stream_write: just write a bunch of bytes.
7 * dsi_stream_read: just read a bunch of bytes.
8 * dsi_stream_send: send a DSI header + data.
9 * dsi_stream_receive: read a DSI header + data.
14 #endif /* HAVE_CONFIG_H */
25 #include <sys/types.h>
26 #include <sys/socket.h>
29 #include <atalk/logger.h>
30 #include <atalk/dsi.h>
31 #include <netatalk/endian.h>
32 #include <atalk/util.h>
34 #define min(a,b) ((a) < (b) ? (a) : (b))
37 #define MSG_MORE 0x8000
41 #define MSG_DONTWAIT 0x40
45 * afpd is sleeping too much while trying to send something.
46 * May be there's no reader or the reader is also sleeping in write,
47 * look if there's some data for us to read, hopefully it will wake up
48 * the reader so we can write again.
50 * @returns 0 when is possible to send again, -1 on error
52 static int dsi_peek(DSI *dsi)
54 static int warned = 0;
55 fd_set readfds, writefds;
60 LOG(log_debug, logtype_dsi, "dsi_peek");
62 maxfd = dsi->socket + 1;
68 if (dsi->eof < dsi->end) {
69 /* space in read buffer */
70 FD_SET( dsi->socket, &readfds);
74 LOG(log_note, logtype_dsi, "dsi_peek: readahead buffer is full, possibly increase -dsireadbuf option");
75 LOG(log_note, logtype_dsi, "dsi_peek: dsireadbuf: %d, DSI quantum: %d, effective buffer size: %d",
77 dsi->server_quantum ? dsi->server_quantum : DSI_SERVQUANT_DEF,
78 dsi->end - dsi->buffer);
82 FD_SET( dsi->socket, &writefds);
84 /* No timeout: if there's nothing to read nor nothing to write,
85 * we've got nothing to do at all */
86 if ((ret = select( maxfd, &readfds, &writefds, NULL, NULL)) <= 0) {
87 if (ret == -1 && errno == EINTR)
88 /* we might have been interrupted by out timer, so restart select */
91 LOG(log_error, logtype_dsi, "dsi_peek: unexpected select return: %d %s",
92 ret, ret < 0 ? strerror(errno) : "");
96 if (FD_ISSET(dsi->socket, &writefds)) {
97 /* we can write again */
98 LOG(log_debug, logtype_dsi, "dsi_peek: can write again");
102 /* Check if there's sth to read, hopefully reading that will unblock the client */
103 if (FD_ISSET(dsi->socket, &readfds)) {
104 len = dsi->end - dsi->eof; /* it's ensured above that there's space */
106 if ((len = read(dsi->socket, dsi->eof, len)) <= 0) {
108 LOG(log_error, logtype_dsi, "dsi_peek: EOF");
111 LOG(log_error, logtype_dsi, "dsi_peek: read: %s", strerror(errno));
116 LOG(log_debug, logtype_dsi, "dsi_peek: read %d bytes", len);
125 /* ------------------------------
126 * write raw data. return actual bytes read. checks against EINTR
127 * aren't necessary if all of the signals have SA_RESTART
129 ssize_t dsi_stream_write(DSI *dsi, void *data, const size_t length, int mode)
133 unsigned int flags = 0;
138 LOG(log_maxdebug, logtype_dsi, "dsi_stream_write: sending %u bytes", length);
140 while (written < length) {
141 len = send(dsi->socket, (u_int8_t *) data + written, length - written, flags);
150 if (errno == EAGAIN || errno == EWOULDBLOCK) {
151 LOG(log_debug, logtype_dsi, "dsi_stream_write: send: %s", strerror(errno));
153 if (mode == DSI_NOWAIT && written == 0) {
154 /* DSI_NOWAIT is used by attention give up in this case. */
159 /* Try to read sth. in order to break up possible deadlock */
160 if (dsi_peek(dsi) != 0) {
164 /* Now try writing again */
168 LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
173 dsi->write_count += written;
181 /* ---------------------------------
184 ssize_t dsi_stream_read_file(DSI *dsi, int fromfd, off_t offset, const size_t length)
189 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read_file: sending %u bytes", length);
194 while (written < length) {
195 len = sys_sendfile(dsi->socket, fromfd, &offset, length - written);
200 if (errno == EINVAL || errno == ENOSYS)
203 if (errno == EAGAIN || errno == EWOULDBLOCK) {
205 /* can't go back to blocking mode, exit, the next read
206 will return with an error and afpd will die.
212 LOG(log_error, logtype_dsi, "dsi_stream_read_file: %s", strerror(errno));
216 /* afpd is going to exit */
218 return -1; /* I think we're at EOF here... */
224 dsi->write_count += written;
231 * Return all bytes up to count from dsi->buffer if there are any buffered there
233 static size_t from_buf(DSI *dsi, u_int8_t *buf, size_t count)
237 if (dsi->buffer == NULL)
238 /* afpd master has no DSI buffering */
241 LOG(log_maxdebug, logtype_dsi, "from_buf: %u bytes", count);
243 nbe = dsi->eof - dsi->start;
246 nbe = min((size_t)nbe, count);
247 memcpy(buf, dsi->start, nbe);
250 if (dsi->eof == dsi->start)
251 dsi->start = dsi->eof = dsi->buffer;
254 LOG(log_debug, logtype_dsi, "from_buf(read: %u, unread:%u , space left: %u): returning %u",
255 dsi->start - dsi->buffer, dsi->eof - dsi->start, dsi->end - dsi->eof, nbe);
261 * Get bytes from buffer dsi->buffer or read from socket
263 * 1. Check if there are bytes in the the dsi->buffer buffer.
264 * 2. Return bytes from (1) if yes.
265 * Note: this may return fewer bytes then requested in count !!
266 * 3. If the buffer was empty, read from the socket.
268 static ssize_t buf_read(DSI *dsi, u_int8_t *buf, size_t count)
272 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes)", count);
277 len = from_buf(dsi, buf, count); /* 1. */
281 len = readt(dsi->socket, buf, count, 0, 1); /* 3. */
283 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes): got: %d", count, len);
289 * Essentially a loop around buf_read() to ensure "length" bytes are read
290 * from dsi->buffer and/or the socket.
292 * @returns length on success, some value smaller then length indicates an error
294 size_t dsi_stream_read(DSI *dsi, void *data, const size_t length)
299 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes)", length);
302 while (stored < length) {
303 len = buf_read(dsi, (u_int8_t *) data + stored, length - stored);
304 if (len == -1 && (errno == EINTR || errno == EAGAIN)) {
305 LOG(log_debug, logtype_dsi, "dsi_stream_read: select read loop");
307 } else if (len > 0) {
309 } else { /* eof or error */
310 /* don't log EOF error if it's just after connect (OSX 10.3 probe) */
311 if (len || stored || dsi->read_count) {
312 if (! (dsi->flags & DSI_DISCONNECTED)) {
313 LOG(log_error, logtype_dsi, "dsi_stream_read: len:%d, %s",
314 len, (len < 0) ? strerror(errno) : "unexpected EOF");
322 dsi->read_count += stored;
324 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes): got: %u", length, stored);
329 * Get "length" bytes from buffer and/or socket. In order to avoid frequent small reads
330 * this tries to read larger chunks (8192 bytes) into a buffer.
332 static size_t dsi_buffered_stream_read(DSI *dsi, u_int8_t *data, const size_t length)
337 LOG(log_maxdebug, logtype_dsi, "dsi_buffered_stream_read: %u bytes", length);
339 len = from_buf(dsi, data, length); /* read from buffer dsi->buffer */
340 dsi->read_count += len;
341 if (len == length) { /* got enough bytes from there ? */
342 return len; /* yes */
345 /* fill the buffer with 8192 bytes or until buffer is full */
346 buflen = min(8192, dsi->end - dsi->eof);
349 ret = read(dsi->socket, dsi->eof, buflen);
354 /* now get the remaining data */
355 len += dsi_stream_read(dsi, data + len, length - len);
359 /* ---------------------------------------
361 static void block_sig(DSI *dsi)
366 /* ---------------------------------------
368 static void unblock_sig(DSI *dsi)
373 /* ---------------------------------------
374 * write data. 0 on failure. this assumes that dsi_len will never
375 * cause an overflow in the data buffer.
377 int dsi_stream_send(DSI *dsi, void *buf, size_t length)
379 char block[DSI_BLOCKSIZ];
384 LOG(log_maxdebug, logtype_dsi, "dsi_stream_send: %u bytes",
385 length ? length : sizeof(block));
387 block[0] = dsi->header.dsi_flags;
388 block[1] = dsi->header.dsi_command;
389 memcpy(block + 2, &dsi->header.dsi_requestID,
390 sizeof(dsi->header.dsi_requestID));
391 memcpy(block + 4, &dsi->header.dsi_code, sizeof(dsi->header.dsi_code));
392 memcpy(block + 8, &dsi->header.dsi_len, sizeof(dsi->header.dsi_len));
393 memcpy(block + 12, &dsi->header.dsi_reserved,
394 sizeof(dsi->header.dsi_reserved));
396 if (!length) { /* just write the header */
397 length = (dsi_stream_write(dsi, block, sizeof(block), 0) == sizeof(block));
398 return length; /* really 0 on failure, 1 on success */
403 iov[0].iov_base = block;
404 iov[0].iov_len = sizeof(block);
405 iov[1].iov_base = buf;
406 iov[1].iov_len = length;
408 towrite = sizeof(block) + length;
409 dsi->write_count += towrite;
410 while (towrite > 0) {
411 if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) || (len == 0))
414 if ((size_t)len == towrite) /* wrote everything out */
416 else if (len < 0) { /* error */
417 if (errno == EAGAIN || errno == EWOULDBLOCK) {
418 if (!dsi_peek(dsi)) {
422 LOG(log_error, logtype_dsi, "dsi_stream_send: %s", strerror(errno));
428 if (towrite > length) { /* skip part of header */
429 iov[0].iov_base = (char *) iov[0].iov_base + len;
430 iov[0].iov_len -= len;
431 } else { /* skip to data */
432 if (iov[0].iov_len) {
433 len -= iov[0].iov_len;
436 iov[1].iov_base = (char *) iov[1].iov_base + len;
437 iov[1].iov_len -= len;
446 /* ---------------------------------------
447 * read data. function on success. 0 on failure. data length gets
448 * stored in length variable. this should really use size_t's, but
449 * that would require changes elsewhere. */
450 int dsi_stream_receive(DSI *dsi, void *buf, const size_t ilength,
453 char block[DSI_BLOCKSIZ];
455 LOG(log_maxdebug, logtype_dsi, "dsi_stream_receive: %u bytes", ilength);
457 /* read in the header */
458 if (dsi_buffered_stream_read(dsi, (u_int8_t *)block, sizeof(block)) != sizeof(block))
461 dsi->header.dsi_flags = block[0];
462 dsi->header.dsi_command = block[1];
463 /* FIXME, not the right place,
464 but we get a server disconnect without reason in the log
467 LOG(log_error, logtype_dsi, "dsi_stream_receive: invalid packet, fatal");
471 memcpy(&dsi->header.dsi_requestID, block + 2,
472 sizeof(dsi->header.dsi_requestID));
473 memcpy(&dsi->header.dsi_code, block + 4, sizeof(dsi->header.dsi_code));
474 memcpy(&dsi->header.dsi_len, block + 8, sizeof(dsi->header.dsi_len));
475 memcpy(&dsi->header.dsi_reserved, block + 12,
476 sizeof(dsi->header.dsi_reserved));
477 dsi->clientID = ntohs(dsi->header.dsi_requestID);
479 /* make sure we don't over-write our buffers. */
480 *rlength = min(ntohl(dsi->header.dsi_len), ilength);
481 if (dsi_stream_read(dsi, buf, *rlength) != *rlength)