* dsi_stream_receive: read a DSI header + data.
*/
-#define USE_WRITEV
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif /* HAVE_CONFIG_H */
#include <stdio.h>
#include <stdlib.h>
+
+#ifdef HAVE_UNISTD_H
#include <unistd.h>
+#endif
+
#include <string.h>
#include <errno.h>
#include <sys/types.h>
-#ifdef USE_WRITEV
+#include <sys/socket.h>
#include <sys/uio.h>
-#endif
-#include <syslog.h>
+#include <atalk/logger.h>
#include <atalk/dsi.h>
#include <netatalk/endian.h>
+#include <atalk/util.h>
#define min(a,b) ((a) < (b) ? (a) : (b))
+#ifndef MSG_MORE
+#define MSG_MORE 0x8000
+#endif
+
+#ifndef MSG_DONTWAIT
+#define MSG_DONTWAIT 0x40
+#endif
+
+/*
+ * afpd is sleeping too much while trying to send something.
+ * May be there's no reader or the reader is also sleeping in write,
+ * look if there's some data for us to read, hopefully it will wake up
+ * the reader so we can write again.
+ *
+ * @returns 0 when is possible to send again, -1 on error
+ */
+static int dsi_peek(DSI *dsi)
+{
+ static int warned = 0;
+ fd_set readfds, writefds;
+ int len;
+ int maxfd;
+ int ret;
+
+ LOG(log_debug, logtype_dsi, "dsi_peek");
+
+ maxfd = dsi->socket + 1;
+
+ while (1) {
+ FD_ZERO(&readfds);
+ FD_ZERO(&writefds);
+
+ if (dsi->eof < dsi->end) {
+ /* space in read buffer */
+ FD_SET( dsi->socket, &readfds);
+ } else {
+ if (!warned) {
+ warned = 1;
+ LOG(log_note, logtype_dsi, "dsi_peek: readahead buffer is full, possibly increase -dsireadbuf option");
+ LOG(log_note, logtype_dsi, "dsi_peek: dsireadbuf: %d, DSI quantum: %d, effective buffer size: %d",
+ dsi->dsireadbuf,
+ dsi->server_quantum ? dsi->server_quantum : DSI_SERVQUANT_DEF,
+ dsi->end - dsi->buffer);
+ }
+ }
+
+ FD_SET( dsi->socket, &writefds);
+
+ /* No timeout: if there's nothing to read nor nothing to write,
+ * we've got nothing to do at all */
+ if ((ret = select( maxfd, &readfds, &writefds, NULL, NULL)) <= 0) {
+ if (ret == -1 && errno == EINTR)
+ /* we might have been interrupted by out timer, so restart select */
+ continue;
+ /* give up */
+ LOG(log_error, logtype_dsi, "dsi_peek: unexpected select return: %d %s",
+ ret, ret < 0 ? strerror(errno) : "");
+ return -1;
+ }
+
+ if (FD_ISSET(dsi->socket, &writefds)) {
+ /* we can write again */
+ LOG(log_debug, logtype_dsi, "dsi_peek: can write again");
+ break;
+ }
+
+ /* Check if there's sth to read, hopefully reading that will unblock the client */
+ if (FD_ISSET(dsi->socket, &readfds)) {
+ len = dsi->end - dsi->eof; /* it's ensured above that there's space */
+
+ if ((len = read(dsi->socket, dsi->eof, len)) <= 0) {
+ if (len == 0) {
+ LOG(log_error, logtype_dsi, "dsi_peek: EOF");
+ return -1;
+ }
+ LOG(log_error, logtype_dsi, "dsi_peek: read: %s", strerror(errno));
+ if (errno == EAGAIN)
+ continue;
+ return -1;
+ }
+ LOG(log_debug, logtype_dsi, "dsi_peek: read %d bytes", len);
+
+ dsi->eof += len;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Return all bytes up to count from dsi->buffer if there are any buffered there
+ */
+static size_t from_buf(DSI *dsi, u_int8_t *buf, size_t count)
+{
+ size_t nbe = 0;
+
+ if (dsi->buffer == NULL)
+ /* afpd master has no DSI buffering */
+ return 0;
+
+ LOG(log_maxdebug, logtype_dsi, "from_buf: %u bytes", count);
+
+ nbe = dsi->eof - dsi->start;
+
+ if (nbe > 0) {
+ nbe = min((size_t)nbe, count);
+ memcpy(buf, dsi->start, nbe);
+ dsi->start += nbe;
+
+ if (dsi->eof == dsi->start)
+ dsi->start = dsi->eof = dsi->buffer;
+ }
+
+ LOG(log_debug, logtype_dsi, "from_buf(read: %u, unread:%u , space left: %u): returning %u",
+ dsi->start - dsi->buffer, dsi->eof - dsi->start, dsi->end - dsi->eof, nbe);
+
+ return nbe;
+}
+
+/*
+ * Get bytes from buffer dsi->buffer or read from socket
+ *
+ * 1. Check if there are bytes in the the dsi->buffer buffer.
+ * 2. Return bytes from (1) if yes.
+ * Note: this may return fewer bytes then requested in count !!
+ * 3. If the buffer was empty, read from the socket.
+ */
+static ssize_t buf_read(DSI *dsi, u_int8_t *buf, size_t count)
+{
+ ssize_t len;
+
+ LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes)", count);
+
+ if (!count)
+ return 0;
+
+ len = from_buf(dsi, buf, count); /* 1. */
+ if (len)
+ return len; /* 2. */
+
+ len = readt(dsi->socket, buf, count, 0, 1); /* 3. */
+
+ LOG(log_maxdebug, logtype_dsi, "buf_read(%u bytes): got: %d", count, len);
+
+ return len;
+}
+
+/*
+ * Get "length" bytes from buffer and/or socket. In order to avoid frequent small reads
+ * this tries to read larger chunks (8192 bytes) into a buffer.
+ */
+static size_t dsi_buffered_stream_read(DSI *dsi, u_int8_t *data, const size_t length)
+{
+ size_t len;
+ size_t buflen;
+
+ LOG(log_maxdebug, logtype_dsi, "dsi_buffered_stream_read: %u bytes", length);
+
+ len = from_buf(dsi, data, length); /* read from buffer dsi->buffer */
+ dsi->read_count += len;
+ if (len == length) { /* got enough bytes from there ? */
+ return len; /* yes */
+ }
+
+ /* fill the buffer with 8192 bytes or until buffer is full */
+ buflen = min(8192, dsi->end - dsi->eof);
+ if (buflen > 0) {
+ ssize_t ret;
+ ret = read(dsi->socket, dsi->eof, buflen);
+ if (ret > 0)
+ dsi->eof += ret;
+ }
+
+ /* now get the remaining data */
+ if ((buflen = dsi_stream_read(dsi, data + len, length - len)) != length - len)
+ return 0;
+ len += buflen;
+
+ return len;
+}
+
+/* ---------------------------------------
+*/
+static void block_sig(DSI *dsi)
+{
+ dsi->in_write++;
+}
+
+/* ---------------------------------------
+*/
+static void unblock_sig(DSI *dsi)
+{
+ dsi->in_write--;
+}
+
+/*********************************************************************************
+ * Public functions
+ *********************************************************************************/
+
+/*!
+ * Communication error with the client, enter disconnected state
+ *
+ * 1. close the socket
+ * 2. set the DSI_DISCONNECTED flag
+ *
+ * @returns 0 if successfully entered disconnected state
+ * -1 if ppid is 1 which means afpd master died
+ * or euid == 0 ie where still running as root (unauthenticated session)
+ */
+int dsi_disconnect(DSI *dsi)
+{
+ dsi->proto_close(dsi); /* 1 */
+ dsi->flags |= DSI_DISCONNECTED; /* 2 */
+ if (geteuid() == 0)
+ return -1;
+ return 0;
+}
-/* write raw data. return actual bytes read. checks against EINTR
+/* ------------------------------
+ * write raw data. return actual bytes read. checks against EINTR
* aren't necessary if all of the signals have SA_RESTART
* specified. */
-size_t dsi_stream_write(DSI *dsi, void *data, const size_t length)
+ssize_t dsi_stream_write(DSI *dsi, void *data, const size_t length, int mode)
{
size_t written;
ssize_t len;
+ unsigned int flags = 0;
+ dsi->in_write++;
written = 0;
+
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_write: sending %u bytes", length);
+
+ if (dsi->flags & DSI_DISCONNECTED)
+ return -1;
+
while (written < length) {
- if (((len = write(dsi->socket, (u_int8_t *) data + written,
- length - written)) == -1 && errno == EINTR) ||
- !len)
- continue;
+ len = send(dsi->socket, (u_int8_t *) data + written, length - written, flags);
+ if (len >= 0) {
+ written += len;
+ continue;
+ }
+
+ if (errno == EINTR)
+ continue;
+
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ LOG(log_debug, logtype_dsi, "dsi_stream_write: send: %s", strerror(errno));
+
+ if (mode == DSI_NOWAIT && written == 0) {
+ /* DSI_NOWAIT is used by attention give up in this case. */
+ written = -1;
+ goto exit;
+ }
+
+ /* Try to read sth. in order to break up possible deadlock */
+ if (dsi_peek(dsi) != 0) {
+ written = -1;
+ goto exit;
+ }
+ /* Now try writing again */
+ continue;
+ }
+
+ LOG(log_error, logtype_dsi, "dsi_stream_write: %s", strerror(errno));
+ written = -1;
+ goto exit;
+ }
+
+ dsi->write_count += written;
+exit:
+ dsi->in_write--;
+ return written;
+}
+
+
+/* ---------------------------------
+*/
+#ifdef WITH_SENDFILE
+ssize_t dsi_stream_read_file(DSI *dsi, int fromfd, off_t offset, const size_t length)
+{
+ size_t written;
+ ssize_t len;
+
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_read_file: sending %u bytes", length);
+
+ if (dsi->flags & DSI_DISCONNECTED)
+ return -1;
+
+ dsi->in_write++;
+ written = 0;
+
+ while (written < length) {
+ len = sys_sendfile(dsi->socket, fromfd, &offset, length - written);
+
if (len < 0) {
- syslog(LOG_ERR, "dsi_stream_write: %m");
+ if (errno == EINTR)
+ continue;
+ if (errno == EINVAL || errno == ENOSYS)
+ return -1;
+
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ if (dsi_peek(dsi)) {
+ /* can't go back to blocking mode, exit, the next read
+ will return with an error and afpd will die.
+ */
+ break;
+ }
+ continue;
+ }
+ LOG(log_error, logtype_dsi, "dsi_stream_read_file: %s", strerror(errno));
break;
}
-
- written += len;
+ else if (!len) {
+ /* afpd is going to exit */
+ errno = EIO;
+ return -1; /* I think we're at EOF here... */
+ }
+ else
+ written += len;
}
dsi->write_count += written;
+ dsi->in_write--;
return written;
}
+#endif
+
-/* read raw data. return actual bytes read. this will wait until
- * it gets length bytes */
+/*
+ * Essentially a loop around buf_read() to ensure "length" bytes are read
+ * from dsi->buffer and/or the socket.
+ *
+ * @returns length on success, some value smaller then length indicates an error
+ */
size_t dsi_stream_read(DSI *dsi, void *data, const size_t length)
{
size_t stored;
ssize_t len;
-
+
+ if (dsi->flags & DSI_DISCONNECTED)
+ return 0;
+
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes)", length);
+
stored = 0;
while (stored < length) {
- if ((len = read(dsi->socket, (u_int8_t *) data + stored,
- length - stored)) == -1 && errno == EINTR)
- continue;
-
- if (len > 0)
- stored += len;
- else {/* eof or error */
- syslog(LOG_ERR, "dsi_stream_read(%d): %m", len);
- break;
- }
+ len = buf_read(dsi, (u_int8_t *) data + stored, length - stored);
+ if (len == -1 && (errno == EINTR || errno == EAGAIN)) {
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_read: select read loop");
+ continue;
+ } else if (len > 0) {
+ stored += len;
+ } else { /* eof or error */
+ /* don't log EOF error if it's just after connect (OSX 10.3 probe) */
+ if (len || stored || dsi->read_count) {
+ if (! (dsi->flags & DSI_DISCONNECTED)) {
+ LOG(log_error, logtype_dsi, "dsi_stream_read: len:%d, %s",
+ len, (len < 0) ? strerror(errno) : "unexpected EOF");
+ }
+ return 0;
+ }
+ break;
+ }
}
dsi->read_count += stored;
+
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_read(%u bytes): got: %u", length, stored);
return stored;
}
-
-/* write data. 0 on failure. this assumes that dsi_len will never
- * cause an overflow in the data buffer. */
+/* ---------------------------------------
+ * write data. 0 on failure. this assumes that dsi_len will never
+ * cause an overflow in the data buffer.
+ */
int dsi_stream_send(DSI *dsi, void *buf, size_t length)
{
char block[DSI_BLOCKSIZ];
- sigset_t oldset;
-#ifdef USE_WRITEV
struct iovec iov[2];
- size_t towrite;
+ size_t towrite;
ssize_t len;
-#endif
+
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_send: %u bytes",
+ length ? length : sizeof(block));
+
+ if (dsi->flags & DSI_DISCONNECTED)
+ return 0;
block[0] = dsi->header.dsi_flags;
block[1] = dsi->header.dsi_command;
memcpy(block + 12, &dsi->header.dsi_reserved,
sizeof(dsi->header.dsi_reserved));
- /* block signals */
- sigprocmask(SIG_BLOCK, &dsi->sigblockset, &oldset);
-
if (!length) { /* just write the header */
- length = (dsi_stream_write(dsi, block, sizeof(block)) == sizeof(block));
- sigprocmask(SIG_SETMASK, &oldset, NULL);
+ length = (dsi_stream_write(dsi, block, sizeof(block), 0) == sizeof(block));
return length; /* really 0 on failure, 1 on success */
}
-#ifdef USE_WRITEV
+ /* block signals */
+ block_sig(dsi);
iov[0].iov_base = block;
iov[0].iov_len = sizeof(block);
iov[1].iov_base = buf;
towrite = sizeof(block) + length;
dsi->write_count += towrite;
while (towrite > 0) {
- if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) ||
- !len)
- continue;
+ if (((len = writev(dsi->socket, iov, 2)) == -1 && errno == EINTR) || (len == 0))
+ continue;
- if (len == towrite) /* wrote everything out */
- break;
- else if (len < 0) { /* error */
- syslog(LOG_ERR, "dsi_stream_send: %m");
- sigprocmask(SIG_SETMASK, &oldset, NULL);
- return 0;
- }
+ if ((size_t)len == towrite) /* wrote everything out */
+ break;
+ else if (len < 0) { /* error */
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ if (!dsi_peek(dsi)) {
+ continue;
+ }
+ }
+ LOG(log_error, logtype_dsi, "dsi_stream_send: %s", strerror(errno));
+ unblock_sig(dsi);
+ return 0;
+ }
- towrite -= len;
- if (towrite > length) { /* skip part of header */
- iov[0].iov_base = (char *) iov[0].iov_base + len;
- iov[0].iov_len -= len;
- } else { /* skip to data */
- if (iov[0].iov_len) {
- len -= iov[0].iov_len;
- iov[0].iov_len = 0;
+ towrite -= len;
+ if (towrite > length) { /* skip part of header */
+ iov[0].iov_base = (char *) iov[0].iov_base + len;
+ iov[0].iov_len -= len;
+ } else { /* skip to data */
+ if (iov[0].iov_len) {
+ len -= iov[0].iov_len;
+ iov[0].iov_len = 0;
+ }
+ iov[1].iov_base = (char *) iov[1].iov_base + len;
+ iov[1].iov_len -= len;
}
- iov[1].iov_base = (char *) iov[1].iov_base + len;
- iov[1].iov_len -= len;
- }
}
-#else
- /* write the header then data */
- if ((dsi_stream_write(dsi, block, sizeof(block)) != sizeof(block)) ||
- (dsi_stream_write(dsi, buf, length) != length)) {
- sigprocmask(SIG_SETMASK, &oldset, NULL);
- return 0;
- }
-#endif
-
- sigprocmask(SIG_SETMASK, &oldset, NULL);
+ unblock_sig(dsi);
return 1;
}
-/* read data. function on success. 0 on failure. data length gets
+/* ---------------------------------------
+ * read data. function on success. 0 on failure. data length gets
* stored in length variable. this should really use size_t's, but
* that would require changes elsewhere. */
-int dsi_stream_receive(DSI *dsi, void *buf, const int ilength,
- int *rlength)
+int dsi_stream_receive(DSI *dsi, void *buf, const size_t ilength,
+ size_t *rlength)
{
char block[DSI_BLOCKSIZ];
+ LOG(log_maxdebug, logtype_dsi, "dsi_stream_receive: %u bytes", ilength);
+
+ if (dsi->flags & DSI_DISCONNECTED)
+ return 0;
+
/* read in the header */
- if (dsi_stream_read(dsi, block, sizeof(block)) != sizeof(block))
+ if (dsi_buffered_stream_read(dsi, (u_int8_t *)block, sizeof(block)) != sizeof(block))
return 0;
dsi->header.dsi_flags = block[0];
dsi->header.dsi_command = block[1];
+ /* FIXME, not the right place,
+ but we get a server disconnect without reason in the log
+ */
+ if (!block[1]) {
+ LOG(log_error, logtype_dsi, "dsi_stream_receive: invalid packet, fatal");
+ return 0;
+ }
+
memcpy(&dsi->header.dsi_requestID, block + 2,
sizeof(dsi->header.dsi_requestID));
memcpy(&dsi->header.dsi_code, block + 4, sizeof(dsi->header.dsi_code));
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