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);
126 * Communication error with the client, enter disconnected state
128 * 1. close the socket
129 * 2. set the DSI_DISCONNECTED flag
131 int dsi_disconnect(DSI *dsi)
133 dsi->proto_close(dsi); /* 1 */
134 dsi->flags |= DSI_DISCONNECTED; /* 2 */
138 /* ------------------------------
139 * write raw data. return actual bytes read. checks against EINTR
140 * aren't necessary if all of the signals have SA_RESTART
142 ssize_t dsi_stream_write(DSI *dsi, void *data, const size_t length, int mode)
146 unsigned int flags = 0;
151 LOG(log_maxdebug, logtype_dsi, "dsi_stream_write: sending %u bytes", length);
153 while (written < length) {
154 len = send(dsi->socket, (u_int8_t *) data + written, length - written, flags);
163 if (errno == EAGAIN || errno == EWOULDBLOCK) {
164 LOG(log_debug, logtype_dsi, "dsi_stream_write: send: %s", strerror(errno));
166 if (mode == DSI_NOWAIT && written == 0) {
167 /* DSI_NOWAIT is used by attention give up in this case. */
172 /* Try to read sth. in order to break up possible deadlock */
173 if (dsi_peek(dsi) != 0) {
177 /* Now try writing again */
181 LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
186 dsi->write_count += written;
194 /* ---------------------------------
197 ssize_t dsi_stream_read_file(DSI *dsi, int fromfd, off_t offset, const size_t length)
202 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read_file: sending %u bytes", length);
207 while (written < length) {
208 len = sys_sendfile(dsi->socket, fromfd, &offset, length - written);
213 if (errno == EINVAL || errno == ENOSYS)
216 if (errno == EAGAIN || errno == EWOULDBLOCK) {
218 /* can't go back to blocking mode, exit, the next read
219 will return with an error and afpd will die.
225 LOG(log_error, logtype_dsi, "dsi_stream_read_file: %s", strerror(errno));
229 /* afpd is going to exit */
231 return -1; /* I think we're at EOF here... */
237 dsi->write_count += written;
244 * Return all bytes up to count from dsi->buffer if there are any buffered there
246 static size_t from_buf(DSI *dsi, u_int8_t *buf, size_t count)
250 if (dsi->buffer == NULL)
251 /* afpd master has no DSI buffering */
254 LOG(log_maxdebug, logtype_dsi, "from_buf: %u bytes", count);
256 nbe = dsi->eof - dsi->start;
259 nbe = min((size_t)nbe, count);
260 memcpy(buf, dsi->start, nbe);
263 if (dsi->eof == dsi->start)
264 dsi->start = dsi->eof = dsi->buffer;
267 LOG(log_debug, logtype_dsi, "from_buf(read: %u, unread:%u , space left: %u): returning %u",
268 dsi->start - dsi->buffer, dsi->eof - dsi->start, dsi->end - dsi->eof, nbe);
274 * Get bytes from buffer dsi->buffer or read from socket
276 * 1. Check if there are bytes in the the dsi->buffer buffer.
277 * 2. Return bytes from (1) if yes.
278 * Note: this may return fewer bytes then requested in count !!
279 * 3. If the buffer was empty, read from the socket.
281 static ssize_t buf_read(DSI *dsi, u_int8_t *buf, size_t count)
285 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes)", count);
290 len = from_buf(dsi, buf, count); /* 1. */
294 len = readt(dsi->socket, buf, count, 0, 1); /* 3. */
296 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes): got: %d", count, len);
302 * Essentially a loop around buf_read() to ensure "length" bytes are read
303 * from dsi->buffer and/or the socket.
305 * @returns length on success, some value smaller then length indicates an error
307 size_t dsi_stream_read(DSI *dsi, void *data, const size_t length)
312 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes)", length);
315 while (stored < length) {
316 len = buf_read(dsi, (u_int8_t *) data + stored, length - stored);
317 if (len == -1 && (errno == EINTR || errno == EAGAIN)) {
318 LOG(log_debug, logtype_dsi, "dsi_stream_read: select read loop");
320 } else if (len > 0) {
322 } else { /* eof or error */
323 /* don't log EOF error if it's just after connect (OSX 10.3 probe) */
324 if (len || stored || dsi->read_count) {
325 if (! (dsi->flags & DSI_DISCONNECTED)) {
326 LOG(log_error, logtype_dsi, "dsi_stream_read: len:%d, %s",
327 len, (len < 0) ? strerror(errno) : "unexpected EOF");
335 dsi->read_count += stored;
337 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes): got: %u", length, stored);
342 * Get "length" bytes from buffer and/or socket. In order to avoid frequent small reads
343 * this tries to read larger chunks (8192 bytes) into a buffer.
345 static size_t dsi_buffered_stream_read(DSI *dsi, u_int8_t *data, const size_t length)
350 LOG(log_maxdebug, logtype_dsi, "dsi_buffered_stream_read: %u bytes", length);
352 len = from_buf(dsi, data, length); /* read from buffer dsi->buffer */
353 dsi->read_count += len;
354 if (len == length) { /* got enough bytes from there ? */
355 return len; /* yes */
358 /* fill the buffer with 8192 bytes or until buffer is full */
359 buflen = min(8192, dsi->end - dsi->eof);
362 ret = read(dsi->socket, dsi->eof, buflen);
367 /* now get the remaining data */
368 if ((buflen = dsi_stream_read(dsi, data + len, length - len)) != length - len)
375 /* ---------------------------------------
377 static void block_sig(DSI *dsi)
382 /* ---------------------------------------
384 static void unblock_sig(DSI *dsi)
389 /* ---------------------------------------
390 * write data. 0 on failure. this assumes that dsi_len will never
391 * cause an overflow in the data buffer.
393 int dsi_stream_send(DSI *dsi, void *buf, size_t length)
395 char block[DSI_BLOCKSIZ];
400 LOG(log_maxdebug, logtype_dsi, "dsi_stream_send: %u bytes",
401 length ? length : sizeof(block));
403 block[0] = dsi->header.dsi_flags;
404 block[1] = dsi->header.dsi_command;
405 memcpy(block + 2, &dsi->header.dsi_requestID,
406 sizeof(dsi->header.dsi_requestID));
407 memcpy(block + 4, &dsi->header.dsi_code, sizeof(dsi->header.dsi_code));
408 memcpy(block + 8, &dsi->header.dsi_len, sizeof(dsi->header.dsi_len));
409 memcpy(block + 12, &dsi->header.dsi_reserved,
410 sizeof(dsi->header.dsi_reserved));
412 if (!length) { /* just write the header */
413 length = (dsi_stream_write(dsi, block, sizeof(block), 0) == sizeof(block));
414 return length; /* really 0 on failure, 1 on success */
419 iov[0].iov_base = block;
420 iov[0].iov_len = sizeof(block);
421 iov[1].iov_base = buf;
422 iov[1].iov_len = length;
424 towrite = sizeof(block) + length;
425 dsi->write_count += towrite;
426 while (towrite > 0) {
427 if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) || (len == 0))
430 if ((size_t)len == towrite) /* wrote everything out */
432 else if (len < 0) { /* error */
433 if (errno == EAGAIN || errno == EWOULDBLOCK) {
434 if (!dsi_peek(dsi)) {
438 LOG(log_error, logtype_dsi, "dsi_stream_send: %s", strerror(errno));
444 if (towrite > length) { /* skip part of header */
445 iov[0].iov_base = (char *) iov[0].iov_base + len;
446 iov[0].iov_len -= len;
447 } else { /* skip to data */
448 if (iov[0].iov_len) {
449 len -= iov[0].iov_len;
452 iov[1].iov_base = (char *) iov[1].iov_base + len;
453 iov[1].iov_len -= len;
462 /* ---------------------------------------
463 * read data. function on success. 0 on failure. data length gets
464 * stored in length variable. this should really use size_t's, but
465 * that would require changes elsewhere. */
466 int dsi_stream_receive(DSI *dsi, void *buf, const size_t ilength,
469 char block[DSI_BLOCKSIZ];
471 LOG(log_maxdebug, logtype_dsi, "dsi_stream_receive: %u bytes", ilength);
473 /* read in the header */
474 if (dsi_buffered_stream_read(dsi, (u_int8_t *)block, sizeof(block)) != sizeof(block))
477 dsi->header.dsi_flags = block[0];
478 dsi->header.dsi_command = block[1];
479 /* FIXME, not the right place,
480 but we get a server disconnect without reason in the log
483 LOG(log_error, logtype_dsi, "dsi_stream_receive: invalid packet, fatal");
487 memcpy(&dsi->header.dsi_requestID, block + 2,
488 sizeof(dsi->header.dsi_requestID));
489 memcpy(&dsi->header.dsi_code, block + 4, sizeof(dsi->header.dsi_code));
490 memcpy(&dsi->header.dsi_len, block + 8, sizeof(dsi->header.dsi_len));
491 memcpy(&dsi->header.dsi_reserved, block + 12,
492 sizeof(dsi->header.dsi_reserved));
493 dsi->clientID = ntohs(dsi->header.dsi_requestID);
495 /* make sure we don't over-write our buffers. */
496 *rlength = min(ntohl(dsi->header.dsi_len), ilength);
497 if (dsi_stream_read(dsi, buf, *rlength) != *rlength)