2 * $Id: dsi_stream.c,v 1.20 2009-10-26 12:35:56 franklahm Exp $
4 * Copyright (c) 1998 Adrian Sun (asun@zoology.washington.edu)
5 * All rights reserved. See COPYRIGHT.
7 * this file provides the following functions:
8 * dsi_stream_write: just write a bunch of bytes.
9 * dsi_stream_read: just read a bunch of bytes.
10 * dsi_stream_send: send a DSI header + data.
11 * dsi_stream_receive: read a DSI header + data.
16 #endif /* HAVE_CONFIG_H */
29 #include <sys/types.h>
30 #include <sys/socket.h>
36 #include <atalk/logger.h>
37 #include <atalk/dsi.h>
38 #include <netatalk/endian.h>
39 #include <atalk/util.h>
41 #define min(a,b) ((a) < (b) ? (a) : (b))
44 #define MSG_MORE 0x8000
48 #define MSG_DONTWAIT 0x40
51 /* -------------------------
52 * we don't use a circular buffer.
54 static void dsi_init_buffer(DSI *dsi)
57 /* XXX config options */
58 dsi->maxsize = 6 * dsi->server_quantum;
60 dsi->maxsize = 6 * DSI_SERVQUANT_DEF;
61 dsi->buffer = malloc(dsi->maxsize);
65 dsi->start = dsi->buffer;
66 dsi->eof = dsi->buffer;
67 dsi->end = dsi->buffer + dsi->maxsize;
71 /* ----------------------
72 afpd is sleeping too much while trying to send something.
73 May be there's no reader or the reader is also sleeping in write,
74 look if there's some data for us to read, hopefully it will wake up
75 the reader so we can write again.
77 static int dsi_peek(DSI *dsi)
79 fd_set readfds, writefds;
86 FD_SET( dsi->socket, &readfds);
87 FD_SET( dsi->socket, &writefds);
88 maxfd = dsi->socket +1;
91 FD_SET( dsi->socket, &readfds);
92 FD_SET( dsi->socket, &writefds);
94 /* No timeout: if there's nothing to read nor nothing to write,
95 * we've got nothing to do at all */
96 if ((ret = select( maxfd, &readfds, &writefds, NULL, NULL)) <= 0) {
97 if (ret == -1 && errno == EINTR)
98 /* we might have been interrupted by out timer, so restart select */
104 /* Check if there's sth to read, hopefully reading that will unblock the client */
105 if (FD_ISSET(dsi->socket, &readfds)) {
106 dsi_init_buffer(dsi);
107 len = dsi->end - dsi->eof;
110 /* ouch, our buffer is full ! fall back to blocking IO
111 * could block and disconnect but it's better than a cpu hog */
115 len = read(dsi->socket, dsi->eof, len);
121 if (FD_ISSET(dsi->socket, &writefds))
122 /* we can write again at last */
129 /* ------------------------------
130 * write raw data. return actual bytes read. checks against EINTR
131 * aren't necessary if all of the signals have SA_RESTART
133 ssize_t dsi_stream_write(DSI *dsi, void *data, const size_t length, int mode)
137 unsigned int flags = 0;
142 LOG(log_maxdebug, logtype_dsi, "dsi_stream_write: sending %u bytes", length);
144 /* non blocking mode */
145 if (setnonblock(dsi->socket, 1) < 0) {
146 LOG(log_error, logtype_dsi, "dsi_stream_write: setnonblock: %s", strerror(errno));
150 while (written < length) {
151 len = send(dsi->socket, (u_int8_t *) data + written, length - written, flags);
160 if (errno == EAGAIN || errno == EWOULDBLOCK) {
161 if (mode == DSI_NOWAIT && written == 0) {
162 /* DSI_NOWAIT is used by attention give up in this case. */
167 /* Try to read sth. in order to break up possible deadlock */
168 if (dsi_peek(dsi) != 0) {
172 /* Now try writing again */
176 LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
181 dsi->write_count += written;
184 if (setnonblock(dsi->socket, 0) < 0) {
185 LOG(log_error, logtype_dsi, "dsi_stream_write: setnonblock: %s", strerror(errno));
194 /* ---------------------------------
197 ssize_t dsi_stream_read_file(DSI *dsi, int fromfd, off_t offset, const size_t length)
205 /* non blocking mode */
206 if (setnonblock(dsi->socket, 1) < 0) {
207 LOG(log_error, logtype_dsi, "dsi_stream_read_file: setnonblock: %s", strerror(errno));
211 while (written < length) {
212 len = sys_sendfile(dsi->socket, fromfd, &offset, length - written);
217 if (errno == EINVAL || errno == ENOSYS)
220 if (errno == EAGAIN || errno == EWOULDBLOCK) {
222 /* can't go back to blocking mode, exit, the next read
223 will return with an error and afpd will die.
229 LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
233 /* afpd is going to exit */
235 return -1; /* I think we're at EOF here... */
241 if (setnonblock(dsi->socket, 0) < 0) {
242 LOG(log_error, logtype_dsi, "dsi_stream_read_file: setnonblock: %s", strerror(errno));
246 dsi->write_count += written;
253 * Return all bytes up to count from dsi->buffer if there are any buffered there
255 static size_t from_buf(DSI *dsi, u_int8_t *buf, size_t count)
260 nbe = dsi->eof - dsi->start;
263 nbe = min((size_t)nbe, count);
264 memcpy(buf, dsi->start, nbe);
267 if (dsi->eof == dsi->start)
268 dsi->start = dsi->eof = dsi->buffer;
276 * Get bytes from buffer dsi->buffer or read from socket
278 * 1. Check if there are bytes in the the dsi->buffer buffer.
279 * 2. Return bytes from (1) if yes.
280 * Note: this may return fewer bytes then requested in count !!
281 * 3. If the buffer was empty, read from the socket.
283 static ssize_t buf_read(DSI *dsi, u_int8_t *buf, size_t count)
290 nbe = from_buf(dsi, buf, count); /* 1. */
294 return read(dsi->socket, buf, count); /* 3. */
298 * Essentially a loop around buf_read() to ensure "length" bytes are read
299 * from dsi->buffer and/or the socket.
301 size_t dsi_stream_read(DSI *dsi, void *data, const size_t length)
307 while (stored < length) {
308 len = buf_read(dsi, (u_int8_t *) data + stored, length - stored);
309 if (len == -1 && errno == EINTR)
313 else { /* eof or error */
314 /* don't log EOF error if it's just after connect (OSX 10.3 probe) */
315 if (len || stored || dsi->read_count) {
316 if (! (dsi->flags & DSI_DISCONNECTED)
318 LOG(log_error, logtype_dsi, "dsi_stream_read(%d): %s", len, (len < 0)?strerror(errno):"unexpected EOF");
324 dsi->read_count += 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 dsi_init_buffer(dsi);
338 len = from_buf(dsi, data, length); /* read from buffer dsi->buffer */
339 dsi->read_count += len;
340 if (len == length) { /* got enough bytes from there ? */
341 return len; /* yes */
344 /* fill the buffer with 8192 bytes or until buffer is full */
345 buflen = min(8192, dsi->end - dsi->eof);
348 ret = read(dsi->socket, dsi->eof, buflen);
353 /* now get the remaining data */
354 len += dsi_stream_read(dsi, data + len, length - len);
358 /* ---------------------------------------
360 void dsi_sleep(DSI *dsi, const int state)
363 dsi->flags |= DSI_SLEEPING;
365 dsi->flags &= ~DSI_SLEEPING;
368 /* ---------------------------------------
370 static void block_sig(DSI *dsi)
375 /* ---------------------------------------
377 static void unblock_sig(DSI *dsi)
382 /* ---------------------------------------
383 * write data. 0 on failure. this assumes that dsi_len will never
384 * cause an overflow in the data buffer.
386 int dsi_stream_send(DSI *dsi, void *buf, size_t length)
388 char block[DSI_BLOCKSIZ];
393 #endif /* USE_WRITEV */
395 block[0] = dsi->header.dsi_flags;
396 block[1] = dsi->header.dsi_command;
397 memcpy(block + 2, &dsi->header.dsi_requestID,
398 sizeof(dsi->header.dsi_requestID));
399 memcpy(block + 4, &dsi->header.dsi_code, sizeof(dsi->header.dsi_code));
400 memcpy(block + 8, &dsi->header.dsi_len, sizeof(dsi->header.dsi_len));
401 memcpy(block + 12, &dsi->header.dsi_reserved,
402 sizeof(dsi->header.dsi_reserved));
404 if (!length) { /* just write the header */
405 length = (dsi_stream_write(dsi, block, sizeof(block), 0) == sizeof(block));
406 return length; /* really 0 on failure, 1 on success */
412 iov[0].iov_base = block;
413 iov[0].iov_len = sizeof(block);
414 iov[1].iov_base = buf;
415 iov[1].iov_len = length;
417 towrite = sizeof(block) + length;
418 dsi->write_count += towrite;
419 while (towrite > 0) {
420 if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) ||
424 if ((size_t)len == towrite) /* wrote everything out */
426 else if (len < 0) { /* error */
427 if (errno == EAGAIN || errno == EWOULDBLOCK) {
428 if (!dsi_peek(dsi)) {
432 LOG(log_error, logtype_dsi, "dsi_stream_send: %s", strerror(errno));
438 if (towrite > length) { /* skip part of header */
439 iov[0].iov_base = (char *) iov[0].iov_base + len;
440 iov[0].iov_len -= len;
441 } else { /* skip to data */
442 if (iov[0].iov_len) {
443 len -= iov[0].iov_len;
446 iov[1].iov_base = (char *) iov[1].iov_base + len;
447 iov[1].iov_len -= len;
451 #else /* USE_WRITEV */
452 /* write the header then data */
453 if ((dsi_stream_write(dsi, block, sizeof(block), 1) != sizeof(block)) ||
454 (dsi_stream_write(dsi, buf, length, 0) != length)) {
458 #endif /* USE_WRITEV */
465 /* ---------------------------------------
466 * read data. function on success. 0 on failure. data length gets
467 * stored in length variable. this should really use size_t's, but
468 * that would require changes elsewhere. */
469 int dsi_stream_receive(DSI *dsi, void *buf, const size_t ilength,
472 char block[DSI_BLOCKSIZ];
474 /* read in the header */
475 if (dsi_buffered_stream_read(dsi, (u_int8_t *)block, sizeof(block)) != sizeof(block))
478 dsi->header.dsi_flags = block[0];
479 dsi->header.dsi_command = block[1];
480 /* FIXME, not the right place,
481 but we get a server disconnect without reason in the log
484 LOG(log_error, logtype_dsi, "dsi_stream_receive: invalid packet, fatal");
488 memcpy(&dsi->header.dsi_requestID, block + 2,
489 sizeof(dsi->header.dsi_requestID));
490 memcpy(&dsi->header.dsi_code, block + 4, sizeof(dsi->header.dsi_code));
491 memcpy(&dsi->header.dsi_len, block + 8, sizeof(dsi->header.dsi_len));
492 memcpy(&dsi->header.dsi_reserved, block + 12,
493 sizeof(dsi->header.dsi_reserved));
494 dsi->clientID = ntohs(dsi->header.dsi_requestID);
496 /* make sure we don't over-write our buffers. */
497 *rlength = min(ntohl(dsi->header.dsi_len), ilength);
498 if (dsi_stream_read(dsi, buf, *rlength) != *rlength)