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 * Return all bytes up to count from dsi->buffer if there are any buffered there
128 static size_t from_buf(DSI *dsi, u_int8_t *buf, size_t count)
132 if (dsi->buffer == NULL)
133 /* afpd master has no DSI buffering */
136 LOG(log_maxdebug, logtype_dsi, "from_buf: %u bytes", count);
138 nbe = dsi->eof - dsi->start;
141 nbe = min((size_t)nbe, count);
142 memcpy(buf, dsi->start, nbe);
145 if (dsi->eof == dsi->start)
146 dsi->start = dsi->eof = dsi->buffer;
149 LOG(log_debug, logtype_dsi, "from_buf(read: %u, unread:%u , space left: %u): returning %u",
150 dsi->start - dsi->buffer, dsi->eof - dsi->start, dsi->end - dsi->eof, nbe);
156 * Get bytes from buffer dsi->buffer or read from socket
158 * 1. Check if there are bytes in the the dsi->buffer buffer.
159 * 2. Return bytes from (1) if yes.
160 * Note: this may return fewer bytes then requested in count !!
161 * 3. If the buffer was empty, read from the socket.
163 static ssize_t buf_read(DSI *dsi, u_int8_t *buf, size_t count)
167 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes)", count);
172 len = from_buf(dsi, buf, count); /* 1. */
176 len = readt(dsi->socket, buf, count, 0, 1); /* 3. */
178 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes): got: %d", count, len);
184 * Get "length" bytes from buffer and/or socket. In order to avoid frequent small reads
185 * this tries to read larger chunks (8192 bytes) into a buffer.
187 static size_t dsi_buffered_stream_read(DSI *dsi, u_int8_t *data, const size_t length)
192 LOG(log_maxdebug, logtype_dsi, "dsi_buffered_stream_read: %u bytes", length);
194 len = from_buf(dsi, data, length); /* read from buffer dsi->buffer */
195 dsi->read_count += len;
196 if (len == length) { /* got enough bytes from there ? */
197 return len; /* yes */
200 /* fill the buffer with 8192 bytes or until buffer is full */
201 buflen = min(8192, dsi->end - dsi->eof);
204 ret = read(dsi->socket, dsi->eof, buflen);
209 /* now get the remaining data */
210 if ((buflen = dsi_stream_read(dsi, data + len, length - len)) != length - len)
217 /* ---------------------------------------
219 static void block_sig(DSI *dsi)
224 /* ---------------------------------------
226 static void unblock_sig(DSI *dsi)
231 /*********************************************************************************
233 *********************************************************************************/
236 * Communication error with the client, enter disconnected state
238 * 1. close the socket
239 * 2. set the DSI_DISCONNECTED flag
241 int dsi_disconnect(DSI *dsi)
243 dsi->proto_close(dsi); /* 1 */
244 dsi->flags |= DSI_DISCONNECTED; /* 2 */
248 /* ------------------------------
249 * write raw data. return actual bytes read. checks against EINTR
250 * aren't necessary if all of the signals have SA_RESTART
252 ssize_t dsi_stream_write(DSI *dsi, void *data, const size_t length, int mode)
256 unsigned int flags = 0;
261 LOG(log_maxdebug, logtype_dsi, "dsi_stream_write: sending %u bytes", length);
263 if (dsi->flags & DSI_DISCONNECTED)
266 while (written < length) {
267 len = send(dsi->socket, (u_int8_t *) data + written, length - written, flags);
276 if (errno == EAGAIN || errno == EWOULDBLOCK) {
277 LOG(log_debug, logtype_dsi, "dsi_stream_write: send: %s", strerror(errno));
279 if (mode == DSI_NOWAIT && written == 0) {
280 /* DSI_NOWAIT is used by attention give up in this case. */
285 /* Try to read sth. in order to break up possible deadlock */
286 if (dsi_peek(dsi) != 0) {
290 /* Now try writing again */
294 LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
299 dsi->write_count += written;
307 /* ---------------------------------
310 ssize_t dsi_stream_read_file(DSI *dsi, int fromfd, off_t offset, const size_t length)
315 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read_file: sending %u bytes", length);
317 if (dsi->flags & DSI_DISCONNECTED)
323 while (written < length) {
324 len = sys_sendfile(dsi->socket, fromfd, &offset, length - written);
329 if (errno == EINVAL || errno == ENOSYS)
332 if (errno == EAGAIN || errno == EWOULDBLOCK) {
334 /* can't go back to blocking mode, exit, the next read
335 will return with an error and afpd will die.
341 LOG(log_error, logtype_dsi, "dsi_stream_read_file: %s", strerror(errno));
345 /* afpd is going to exit */
347 return -1; /* I think we're at EOF here... */
353 dsi->write_count += written;
361 * Essentially a loop around buf_read() to ensure "length" bytes are read
362 * from dsi->buffer and/or the socket.
364 * @returns length on success, some value smaller then length indicates an error
366 size_t dsi_stream_read(DSI *dsi, void *data, const size_t length)
371 if (dsi->flags & DSI_DISCONNECTED)
374 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes)", length);
377 while (stored < length) {
378 len = buf_read(dsi, (u_int8_t *) data + stored, length - stored);
379 if (len == -1 && (errno == EINTR || errno == EAGAIN)) {
380 LOG(log_debug, logtype_dsi, "dsi_stream_read: select read loop");
382 } else if (len > 0) {
384 } else { /* eof or error */
385 /* don't log EOF error if it's just after connect (OSX 10.3 probe) */
386 if (len || stored || dsi->read_count) {
387 if (! (dsi->flags & DSI_DISCONNECTED)) {
388 LOG(log_error, logtype_dsi, "dsi_stream_read: len:%d, %s",
389 len, (len < 0) ? strerror(errno) : "unexpected EOF");
397 dsi->read_count += stored;
399 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes): got: %u", length, stored);
403 /* ---------------------------------------
404 * write data. 0 on failure. this assumes that dsi_len will never
405 * cause an overflow in the data buffer.
407 int dsi_stream_send(DSI *dsi, void *buf, size_t length)
409 char block[DSI_BLOCKSIZ];
414 LOG(log_maxdebug, logtype_dsi, "dsi_stream_send: %u bytes",
415 length ? length : sizeof(block));
417 if (dsi->flags & DSI_DISCONNECTED)
420 block[0] = dsi->header.dsi_flags;
421 block[1] = dsi->header.dsi_command;
422 memcpy(block + 2, &dsi->header.dsi_requestID,
423 sizeof(dsi->header.dsi_requestID));
424 memcpy(block + 4, &dsi->header.dsi_code, sizeof(dsi->header.dsi_code));
425 memcpy(block + 8, &dsi->header.dsi_len, sizeof(dsi->header.dsi_len));
426 memcpy(block + 12, &dsi->header.dsi_reserved,
427 sizeof(dsi->header.dsi_reserved));
429 if (!length) { /* just write the header */
430 length = (dsi_stream_write(dsi, block, sizeof(block), 0) == sizeof(block));
431 return length; /* really 0 on failure, 1 on success */
436 iov[0].iov_base = block;
437 iov[0].iov_len = sizeof(block);
438 iov[1].iov_base = buf;
439 iov[1].iov_len = length;
441 towrite = sizeof(block) + length;
442 dsi->write_count += towrite;
443 while (towrite > 0) {
444 if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) || (len == 0))
447 if ((size_t)len == towrite) /* wrote everything out */
449 else if (len < 0) { /* error */
450 if (errno == EAGAIN || errno == EWOULDBLOCK) {
451 if (!dsi_peek(dsi)) {
455 LOG(log_error, logtype_dsi, "dsi_stream_send: %s", strerror(errno));
461 if (towrite > length) { /* skip part of header */
462 iov[0].iov_base = (char *) iov[0].iov_base + len;
463 iov[0].iov_len -= len;
464 } else { /* skip to data */
465 if (iov[0].iov_len) {
466 len -= iov[0].iov_len;
469 iov[1].iov_base = (char *) iov[1].iov_base + len;
470 iov[1].iov_len -= len;
479 /* ---------------------------------------
480 * read data. function on success. 0 on failure. data length gets
481 * stored in length variable. this should really use size_t's, but
482 * that would require changes elsewhere. */
483 int dsi_stream_receive(DSI *dsi, void *buf, const size_t ilength,
486 char block[DSI_BLOCKSIZ];
488 LOG(log_maxdebug, logtype_dsi, "dsi_stream_receive: %u bytes", ilength);
490 if (dsi->flags & DSI_DISCONNECTED)
493 /* read in the header */
494 if (dsi_buffered_stream_read(dsi, (u_int8_t *)block, sizeof(block)) != sizeof(block))
497 dsi->header.dsi_flags = block[0];
498 dsi->header.dsi_command = block[1];
499 /* FIXME, not the right place,
500 but we get a server disconnect without reason in the log
503 LOG(log_error, logtype_dsi, "dsi_stream_receive: invalid packet, fatal");
507 memcpy(&dsi->header.dsi_requestID, block + 2,
508 sizeof(dsi->header.dsi_requestID));
509 memcpy(&dsi->header.dsi_code, block + 4, sizeof(dsi->header.dsi_code));
510 memcpy(&dsi->header.dsi_len, block + 8, sizeof(dsi->header.dsi_len));
511 memcpy(&dsi->header.dsi_reserved, block + 12,
512 sizeof(dsi->header.dsi_reserved));
513 dsi->clientID = ntohs(dsi->header.dsi_requestID);
515 /* make sure we don't over-write our buffers. */
516 *rlength = min(ntohl(dsi->header.dsi_len), ilength);
517 if (dsi_stream_read(dsi, buf, *rlength) != *rlength)