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 <atalk/util.h>
33 #define min(a,b) ((a) < (b) ? (a) : (b))
36 #define MSG_MORE 0x8000
40 #define MSG_DONTWAIT 0x40
44 * afpd is sleeping too much while trying to send something.
45 * May be there's no reader or the reader is also sleeping in write,
46 * look if there's some data for us to read, hopefully it will wake up
47 * the reader so we can write again.
49 * @returns 0 when is possible to send again, -1 on error
51 static int dsi_peek(DSI *dsi)
53 static int warned = 0;
54 fd_set readfds, writefds;
59 LOG(log_debug, logtype_dsi, "dsi_peek");
61 maxfd = dsi->socket + 1;
67 if (dsi->eof < dsi->end) {
68 /* space in read buffer */
69 FD_SET( dsi->socket, &readfds);
73 LOG(log_note, logtype_dsi, "dsi_peek: readahead buffer is full, possibly increase -dsireadbuf option");
74 LOG(log_note, logtype_dsi, "dsi_peek: dsireadbuf: %d, DSI quantum: %d, effective buffer size: %d",
76 dsi->server_quantum ? dsi->server_quantum : DSI_SERVQUANT_DEF,
77 dsi->end - dsi->buffer);
81 FD_SET( dsi->socket, &writefds);
83 /* No timeout: if there's nothing to read nor nothing to write,
84 * we've got nothing to do at all */
85 if ((ret = select( maxfd, &readfds, &writefds, NULL, NULL)) <= 0) {
86 if (ret == -1 && errno == EINTR)
87 /* we might have been interrupted by out timer, so restart select */
90 LOG(log_error, logtype_dsi, "dsi_peek: unexpected select return: %d %s",
91 ret, ret < 0 ? strerror(errno) : "");
95 if (FD_ISSET(dsi->socket, &writefds)) {
96 /* we can write again */
97 LOG(log_debug, logtype_dsi, "dsi_peek: can write again");
101 /* Check if there's sth to read, hopefully reading that will unblock the client */
102 if (FD_ISSET(dsi->socket, &readfds)) {
103 len = dsi->end - dsi->eof; /* it's ensured above that there's space */
105 if ((len = read(dsi->socket, dsi->eof, len)) <= 0) {
107 LOG(log_error, logtype_dsi, "dsi_peek: EOF");
110 LOG(log_error, logtype_dsi, "dsi_peek: read: %s", strerror(errno));
115 LOG(log_debug, logtype_dsi, "dsi_peek: read %d bytes", len);
124 /* ------------------------------
125 * write raw data. return actual bytes read. checks against EINTR
126 * aren't necessary if all of the signals have SA_RESTART
128 ssize_t dsi_stream_write(DSI *dsi, void *data, const size_t length, int mode)
132 unsigned int flags = 0;
137 LOG(log_maxdebug, logtype_dsi, "dsi_stream_write: sending %u bytes", length);
139 while (written < length) {
140 len = send(dsi->socket, (u_int8_t *) data + written, length - written, flags);
149 if (errno == EAGAIN || errno == EWOULDBLOCK) {
150 LOG(log_debug, logtype_dsi, "dsi_stream_write: send: %s", strerror(errno));
152 if (mode == DSI_NOWAIT && written == 0) {
153 /* DSI_NOWAIT is used by attention give up in this case. */
158 /* Try to read sth. in order to break up possible deadlock */
159 if (dsi_peek(dsi) != 0) {
163 /* Now try writing again */
167 LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
172 dsi->write_count += written;
180 /* ---------------------------------
183 ssize_t dsi_stream_read_file(DSI *dsi, int fromfd, off_t offset, const size_t length)
188 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read_file: sending %u bytes", length);
193 while (written < length) {
194 len = sys_sendfile(dsi->socket, fromfd, &offset, length - written);
199 if (errno == EINVAL || errno == ENOSYS)
202 if (errno == EAGAIN || errno == EWOULDBLOCK) {
204 /* can't go back to blocking mode, exit, the next read
205 will return with an error and afpd will die.
211 LOG(log_error, logtype_dsi, "dsi_stream_read_file: %s", strerror(errno));
215 /* afpd is going to exit */
217 return -1; /* I think we're at EOF here... */
223 dsi->write_count += written;
230 * Return all bytes up to count from dsi->buffer if there are any buffered there
232 static size_t from_buf(DSI *dsi, u_int8_t *buf, size_t count)
236 if (dsi->buffer == NULL)
237 /* afpd master has no DSI buffering */
240 LOG(log_maxdebug, logtype_dsi, "from_buf: %u bytes", count);
242 nbe = dsi->eof - dsi->start;
245 nbe = min((size_t)nbe, count);
246 memcpy(buf, dsi->start, nbe);
249 if (dsi->eof == dsi->start)
250 dsi->start = dsi->eof = dsi->buffer;
253 LOG(log_debug, logtype_dsi, "from_buf(read: %u, unread:%u , space left: %u): returning %u",
254 dsi->start - dsi->buffer, dsi->eof - dsi->start, dsi->end - dsi->eof, nbe);
260 * Get bytes from buffer dsi->buffer or read from socket
262 * 1. Check if there are bytes in the the dsi->buffer buffer.
263 * 2. Return bytes from (1) if yes.
264 * Note: this may return fewer bytes then requested in count !!
265 * 3. If the buffer was empty, read from the socket.
267 static ssize_t buf_read(DSI *dsi, u_int8_t *buf, size_t count)
271 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes)", count);
276 len = from_buf(dsi, buf, count); /* 1. */
280 len = readt(dsi->socket, buf, count, 0, 1); /* 3. */
282 LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes): got: %d", count, len);
288 * Essentially a loop around buf_read() to ensure "length" bytes are read
289 * from dsi->buffer and/or the socket.
291 * @returns length on success, some value smaller then length indicates an error
293 size_t dsi_stream_read(DSI *dsi, void *data, const size_t length)
298 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes)", length);
301 while (stored < length) {
302 len = buf_read(dsi, (u_int8_t *) data + stored, length - stored);
303 if (len == -1 && (errno == EINTR || errno == EAGAIN)) {
304 LOG(log_debug, logtype_dsi, "dsi_stream_read: select read loop");
306 } else if (len > 0) {
308 } else { /* eof or error */
309 /* don't log EOF error if it's just after connect (OSX 10.3 probe) */
310 if (len || stored || dsi->read_count) {
311 if (! (dsi->flags & DSI_DISCONNECTED)) {
312 LOG(log_error, logtype_dsi, "dsi_stream_read: len:%d, %s",
313 len, (len < 0) ? strerror(errno) : "unexpected EOF");
321 dsi->read_count += stored;
323 LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes): got: %u", length, stored);
328 * Get "length" bytes from buffer and/or socket. In order to avoid frequent small reads
329 * this tries to read larger chunks (8192 bytes) into a buffer.
331 static size_t dsi_buffered_stream_read(DSI *dsi, u_int8_t *data, const size_t length)
336 LOG(log_maxdebug, logtype_dsi, "dsi_buffered_stream_read: %u bytes", length);
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 static void block_sig(DSI *dsi)
365 /* ---------------------------------------
367 static void unblock_sig(DSI *dsi)
372 /* ---------------------------------------
373 * write data. 0 on failure. this assumes that dsi_len will never
374 * cause an overflow in the data buffer.
376 int dsi_stream_send(DSI *dsi, void *buf, size_t length)
378 char block[DSI_BLOCKSIZ];
383 LOG(log_maxdebug, logtype_dsi, "dsi_stream_send: %u bytes",
384 length ? length : sizeof(block));
386 block[0] = dsi->header.dsi_flags;
387 block[1] = dsi->header.dsi_command;
388 memcpy(block + 2, &dsi->header.dsi_requestID,
389 sizeof(dsi->header.dsi_requestID));
390 memcpy(block + 4, &dsi->header.dsi_code, sizeof(dsi->header.dsi_code));
391 memcpy(block + 8, &dsi->header.dsi_len, sizeof(dsi->header.dsi_len));
392 memcpy(block + 12, &dsi->header.dsi_reserved,
393 sizeof(dsi->header.dsi_reserved));
395 if (!length) { /* just write the header */
396 length = (dsi_stream_write(dsi, block, sizeof(block), 0) == sizeof(block));
397 return length; /* really 0 on failure, 1 on success */
402 iov[0].iov_base = block;
403 iov[0].iov_len = sizeof(block);
404 iov[1].iov_base = buf;
405 iov[1].iov_len = length;
407 towrite = sizeof(block) + length;
408 dsi->write_count += towrite;
409 while (towrite > 0) {
410 if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) || (len == 0))
413 if ((size_t)len == towrite) /* wrote everything out */
415 else if (len < 0) { /* error */
416 if (errno == EAGAIN || errno == EWOULDBLOCK) {
417 if (!dsi_peek(dsi)) {
421 LOG(log_error, logtype_dsi, "dsi_stream_send: %s", strerror(errno));
427 if (towrite > length) { /* skip part of header */
428 iov[0].iov_base = (char *) iov[0].iov_base + len;
429 iov[0].iov_len -= len;
430 } else { /* skip to data */
431 if (iov[0].iov_len) {
432 len -= iov[0].iov_len;
435 iov[1].iov_base = (char *) iov[1].iov_base + len;
436 iov[1].iov_len -= len;
445 /* ---------------------------------------
446 * read data. function on success. 0 on failure. data length gets
447 * stored in length variable. this should really use size_t's, but
448 * that would require changes elsewhere. */
449 int dsi_stream_receive(DSI *dsi, void *buf, const size_t ilength,
452 char block[DSI_BLOCKSIZ];
454 LOG(log_maxdebug, logtype_dsi, "dsi_stream_receive: %u bytes", ilength);
456 /* read in the header */
457 if (dsi_buffered_stream_read(dsi, (u_int8_t *)block, sizeof(block)) != sizeof(block))
460 dsi->header.dsi_flags = block[0];
461 dsi->header.dsi_command = block[1];
462 /* FIXME, not the right place,
463 but we get a server disconnect without reason in the log
466 LOG(log_error, logtype_dsi, "dsi_stream_receive: invalid packet, fatal");
470 memcpy(&dsi->header.dsi_requestID, block + 2,
471 sizeof(dsi->header.dsi_requestID));
472 memcpy(&dsi->header.dsi_code, block + 4, sizeof(dsi->header.dsi_code));
473 memcpy(&dsi->header.dsi_len, block + 8, sizeof(dsi->header.dsi_len));
474 memcpy(&dsi->header.dsi_reserved, block + 12,
475 sizeof(dsi->header.dsi_reserved));
476 dsi->clientID = ntohs(dsi->header.dsi_requestID);
478 /* make sure we don't over-write our buffers. */
479 *rlength = min(ntohl(dsi->header.dsi_len), ilength);
480 if (dsi_stream_read(dsi, buf, *rlength) != *rlength)