/* libguestfs - the guestfsd daemon
- * Copyright (C) 2009 Red Hat Inc.
+ * Copyright (C) 2009 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
+#include <inttypes.h>
#include <unistd.h>
+#include <errno.h>
+#include <sys/param.h> /* defines MIN */
+#include <sys/select.h>
+#include <sys/time.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
+#ifdef HAVE_WINDOWS_H
+#include <windows.h>
+#endif
+
+#include "c-ctype.h"
+#include "ignore-value.h"
+
#include "daemon.h"
+#include "guestfs_protocol.h"
+#include "errnostring.h"
/* The message currently being processed. */
int proc_nr;
int serial;
+/* Hint for implementing progress messages for uploaded/incoming data.
+ * The caller sets this to a value > 0 if it knows or can estimate how
+ * much data will be sent (this is not always known, eg. for uploads
+ * coming from a pipe). If this is known then we can emit progress
+ * messages as we write the data.
+ */
+uint64_t progress_hint;
+
+/* Optional arguments bitmask. Caller sets this to indicate which
+ * optional arguments in the guestfs_<foo>_args structure are
+ * meaningful. Optional arguments not covered by the bitmask are set
+ * to arbitrary values and the daemon should ignore them. If the
+ * bitmask has bits set that the daemon doesn't understand, then the
+ * whole call is rejected early in processing.
+ */
+uint64_t optargs_bitmask;
+
+/* Time at which we received the current request. */
+static struct timeval start_t;
+
+/* Time at which the last progress notification was sent. */
+static struct timeval last_progress_t;
+
+/* Counts the number of progress notifications sent during this call. */
+static int count_progress;
+
/* The daemon communications socket. */
static int sock;
void
main_loop (int _sock)
{
+ XDR xdr;
+ char *buf;
+ char lenbuf[4];
+ uint32_t len;
+ struct guestfs_message_header hdr;
+
sock = _sock;
-
+ for (;;) {
+ /* Most common errors are leaked memory and leaked file descriptors,
+ * so run this between each command:
+ */
+ if (verbose && 0)
+ ignore_value (system ("ls -l /proc/self/fd"));
+
+ /* Read the length word. */
+ if (xread (sock, lenbuf, 4) == -1)
+ exit (EXIT_FAILURE);
+
+ xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE);
+ xdr_u_int (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ if (len > GUESTFS_MESSAGE_MAX) {
+ fprintf (stderr, "guestfsd: incoming message is too long (%u bytes)\n",
+ len);
+ exit (EXIT_FAILURE);
+ }
+
+ buf = malloc (len);
+ if (!buf) {
+ reply_with_perror ("malloc");
+ continue;
+ }
+
+ if (xread (sock, buf, len) == -1)
+ exit (EXIT_FAILURE);
+#ifdef ENABLE_PACKET_DUMP
+ if (verbose) {
+ size_t i, j;
+ for (i = 0; i < len; i += 16) {
+ printf ("%04zx: ", i);
+ for (j = i; j < MIN (i+16, len); ++j)
+ printf ("%02x ", (unsigned char) buf[j]);
+ for (; j < i+16; ++j)
+ printf (" ");
+ printf ("|");
+ for (j = i; j < MIN (i+16, len); ++j)
+ if (c_isprint (buf[j]))
+ printf ("%c", buf[j]);
+ else
+ printf (".");
+ for (; j < i+16; ++j)
+ printf (" ");
+ printf ("|\n");
+ }
+ }
+#endif
+
+ gettimeofday (&start_t, NULL);
+ last_progress_t = start_t;
+ count_progress = 0;
+
+ /* Decode the message header. */
+ xdrmem_create (&xdr, buf, len, XDR_DECODE);
+ if (!xdr_guestfs_message_header (&xdr, &hdr)) {
+ fprintf (stderr, "guestfsd: could not decode message header\n");
+ exit (EXIT_FAILURE);
+ }
+
+ /* Check the version etc. */
+ if (hdr.prog != GUESTFS_PROGRAM) {
+ reply_with_error ("wrong program (%d)", hdr.prog);
+ goto cont;
+ }
+ if (hdr.vers != GUESTFS_PROTOCOL_VERSION) {
+ reply_with_error ("wrong protocol version (%d)", hdr.vers);
+ goto cont;
+ }
+ if (hdr.direction != GUESTFS_DIRECTION_CALL) {
+ reply_with_error ("unexpected message direction (%d)", hdr.direction);
+ goto cont;
+ }
+ if (hdr.status != GUESTFS_STATUS_OK) {
+ reply_with_error ("unexpected message status (%d)", hdr.status);
+ goto cont;
+ }
+ /* This version of the daemon does not understand optional arguments
+ * at all. When we fix this, we will remove the next conditional.
+ */
+ if (hdr.optargs_bitmask != 0) {
+ reply_with_error ("optargs_bitmask != 0 (%" PRIu64 ")",
+ hdr.optargs_bitmask);
+ goto cont;
+ }
+
+ proc_nr = hdr.proc;
+ serial = hdr.serial;
+ progress_hint = hdr.progress_hint;
+ optargs_bitmask = hdr.optargs_bitmask;
+
+ /* Clear errors before we call the stub functions. This is just
+ * to ensure that we can accurately report errors in cases where
+ * error handling paths don't set errno correctly.
+ */
+ errno = 0;
+#ifdef WIN32
+ SetLastError (0);
+ WSASetLastError (0);
+#endif
+
+ /* Now start to process this message. */
+ dispatch_incoming_message (&xdr);
+ /* Note that dispatch_incoming_message will also send a reply. */
+
+ /* In verbose mode, display the time taken to run each command. */
+ if (verbose) {
+ struct timeval end_t;
+ gettimeofday (&end_t, NULL);
+
+ int64_t start_us, end_us, elapsed_us;
+ start_us = (int64_t) start_t.tv_sec * 1000000 + start_t.tv_usec;
+ end_us = (int64_t) end_t.tv_sec * 1000000 + end_t.tv_usec;
+ elapsed_us = end_us - start_us;
+
+ fprintf (stderr, "proc %d (%s) took %d.%02d seconds\n",
+ proc_nr,
+ proc_nr >= 0 && proc_nr < GUESTFS_PROC_NR_PROCS
+ ? function_names[proc_nr] : "UNKNOWN PROCEDURE",
+ (int) (elapsed_us / 1000000),
+ (int) ((elapsed_us / 10000) % 100));
+ }
+
+ cont:
+ xdr_destroy (&xdr);
+ free (buf);
+ }
}
+static void send_error (int errnum, const char *msg);
+
void
reply_with_error (const char *fs, ...)
{
-
+ char err[GUESTFS_ERROR_LEN];
+ va_list args;
+ va_start (args, fs);
+ vsnprintf (err, sizeof err, fs, args);
+ va_end (args);
+ send_error (0, err);
}
void
-reply (xdrproc_t xdrp, XDR *xdr)
+reply_with_perror_errno (int err, const char *fs, ...)
{
+ char buf1[GUESTFS_ERROR_LEN];
+ char buf2[GUESTFS_ERROR_LEN];
+ va_list args;
+
+ va_start (args, fs);
+ vsnprintf (buf1, sizeof buf1, fs, args);
+ va_end (args);
+
+ snprintf (buf2, sizeof buf2, "%s: %s", buf1, strerror (err));
+
+ send_error (err, buf2);
+}
+
+static void
+send_error (int errnum, const char *msg)
+{
+ XDR xdr;
+ char buf[GUESTFS_ERROR_LEN + 200];
+ char lenbuf[4];
+ struct guestfs_message_header hdr;
+ struct guestfs_message_error err;
+ unsigned len;
+
+ fprintf (stderr, "guestfsd: error: %s\n", msg);
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
+
+ hdr.prog = GUESTFS_PROGRAM;
+ hdr.vers = GUESTFS_PROTOCOL_VERSION;
+ hdr.direction = GUESTFS_DIRECTION_REPLY;
+ hdr.status = GUESTFS_STATUS_ERROR;
+ hdr.proc = proc_nr;
+ hdr.serial = serial;
+
+ if (!xdr_guestfs_message_header (&xdr, &hdr)) {
+ fprintf (stderr, "guestfsd: failed to encode error message header\n");
+ exit (EXIT_FAILURE);
+ }
+
+ /* These strings are not going to be freed. We just cast them
+ * to (char *) because they are defined that way in the XDR structs.
+ */
+ err.errno_string =
+ (char *) (errnum > 0 ? guestfs___errno_to_string (errnum) : "");
+ err.error_message = (char *) msg;
+
+ if (!xdr_guestfs_message_error (&xdr, &err)) {
+ fprintf (stderr, "guestfsd: failed to encode error message body\n");
+ exit (EXIT_FAILURE);
+ }
+
+ len = xdr_getpos (&xdr);
+ xdr_destroy (&xdr);
+
+ xdrmem_create (&xdr, lenbuf, 4, XDR_ENCODE);
+ xdr_u_int (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ if (xwrite (sock, lenbuf, 4) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (EXIT_FAILURE);
+ }
+ if (xwrite (sock, buf, len) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (EXIT_FAILURE);
+ }
+}
+
+void
+reply (xdrproc_t xdrp, char *ret)
+{
+ XDR xdr;
+ char buf[GUESTFS_MESSAGE_MAX];
+ char lenbuf[4];
+ struct guestfs_message_header hdr;
+ unsigned len;
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
+
+ hdr.prog = GUESTFS_PROGRAM;
+ hdr.vers = GUESTFS_PROTOCOL_VERSION;
+ hdr.direction = GUESTFS_DIRECTION_REPLY;
+ hdr.status = GUESTFS_STATUS_OK;
+ hdr.proc = proc_nr;
+ hdr.serial = serial;
+
+ if (!xdr_guestfs_message_header (&xdr, &hdr)) {
+ fprintf (stderr, "guestfsd: failed to encode reply header\n");
+ exit (EXIT_FAILURE);
+ }
+
+ if (xdrp) {
+ /* This can fail if the reply body is too large, for example
+ * if it exceeds the maximum message size. In that case
+ * we want to return an error message instead. (RHBZ#509597).
+ */
+ if (!(*xdrp) (&xdr, ret)) {
+ reply_with_error ("guestfsd: failed to encode reply body\n(maybe the reply exceeds the maximum message size in the protocol?)");
+ xdr_destroy (&xdr);
+ return;
+ }
+ }
+
+ len = xdr_getpos (&xdr);
+ xdr_destroy (&xdr);
+
+ xdrmem_create (&xdr, lenbuf, 4, XDR_ENCODE);
+ xdr_u_int (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ if (xwrite (sock, lenbuf, 4) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (EXIT_FAILURE);
+ }
+ if (xwrite (sock, buf, len) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (EXIT_FAILURE);
+ }
+}
+
+/* Receive file chunks, repeatedly calling 'cb'. */
+int
+receive_file (receive_cb cb, void *opaque)
+{
+ guestfs_chunk chunk;
+ char lenbuf[4];
+ char *buf;
+ XDR xdr;
+ int r;
+ uint32_t len;
+
+ for (;;) {
+ if (verbose)
+ fprintf (stderr, "receive_file: reading length word\n");
+
+ /* Read the length word. */
+ if (xread (sock, lenbuf, 4) == -1)
+ exit (EXIT_FAILURE);
+
+ xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE);
+ xdr_u_int (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ if (len == GUESTFS_CANCEL_FLAG)
+ continue; /* Just ignore it. */
+
+ if (len > GUESTFS_MESSAGE_MAX) {
+ fprintf (stderr, "guestfsd: incoming message is too long (%u bytes)\n",
+ len);
+ exit (EXIT_FAILURE);
+ }
+
+ buf = malloc (len);
+ if (!buf) {
+ perror ("malloc");
+ return -1;
+ }
+
+ if (xread (sock, buf, len) == -1)
+ exit (EXIT_FAILURE);
+
+ xdrmem_create (&xdr, buf, len, XDR_DECODE);
+ memset (&chunk, 0, sizeof chunk);
+ if (!xdr_guestfs_chunk (&xdr, &chunk)) {
+ xdr_destroy (&xdr);
+ free (buf);
+ return -1;
+ }
+ xdr_destroy (&xdr);
+ free (buf);
+
+ if (verbose)
+ fprintf (stderr, "receive_file: got chunk: cancel = %d, len = %d, buf = %p\n",
+ chunk.cancel, chunk.data.data_len, chunk.data.data_val);
+
+ if (chunk.cancel) {
+ if (verbose)
+ fprintf (stderr, "receive_file: received cancellation from library\n");
+ xdr_free ((xdrproc_t) xdr_guestfs_chunk, (char *) &chunk);
+ return -2;
+ }
+ if (chunk.data.data_len == 0) {
+ if (verbose)
+ fprintf (stderr, "receive_file: end of file, leaving function\n");
+ xdr_free ((xdrproc_t) xdr_guestfs_chunk, (char *) &chunk);
+ return 0; /* end of file */
+ }
+
+ /* Note that the callback can generate progress messages. */
+ if (cb)
+ r = cb (opaque, chunk.data.data_val, chunk.data.data_len);
+ else
+ r = 0;
+
+ xdr_free ((xdrproc_t) xdr_guestfs_chunk, (char *) &chunk);
+ if (r == -1) { /* write error */
+ if (verbose)
+ fprintf (stderr, "receive_file: write error\n");
+ return -1;
+ }
+ }
+}
+
+/* Send a cancellation flag back to the library. */
+int
+cancel_receive (void)
+{
+ XDR xdr;
+ char fbuf[4];
+ uint32_t flag = GUESTFS_CANCEL_FLAG;
+
+ xdrmem_create (&xdr, fbuf, sizeof fbuf, XDR_ENCODE);
+ xdr_u_int (&xdr, &flag);
+ xdr_destroy (&xdr);
+
+ if (xwrite (sock, fbuf, sizeof fbuf) == -1) {
+ perror ("write to socket");
+ return -1;
+ }
+
+ /* Keep receiving chunks and discarding, until library sees cancel. */
+ return receive_file (NULL, NULL);
+}
+
+static int check_for_library_cancellation (void);
+static int send_chunk (const guestfs_chunk *);
+
+/* Also check if the library sends us a cancellation message. */
+int
+send_file_write (const void *buf, int len)
+{
+ guestfs_chunk chunk;
+ int cancel;
+
+ if (len > GUESTFS_MAX_CHUNK_SIZE) {
+ fprintf (stderr, "send_file_write: len (%d) > GUESTFS_MAX_CHUNK_SIZE (%d)\n",
+ len, GUESTFS_MAX_CHUNK_SIZE);
+ return -1;
+ }
+
+ cancel = check_for_library_cancellation ();
+
+ if (cancel) {
+ chunk.cancel = 1;
+ chunk.data.data_len = 0;
+ chunk.data.data_val = NULL;
+ } else {
+ chunk.cancel = 0;
+ chunk.data.data_len = len;
+ chunk.data.data_val = (char *) buf;
+ }
+
+ if (send_chunk (&chunk) == -1)
+ return -1;
+
+ if (cancel) return -2;
+ return 0;
+}
+
+static int
+check_for_library_cancellation (void)
+{
+ fd_set rset;
+ struct timeval tv;
+ int r;
+ char buf[4];
+ uint32_t flag;
+ XDR xdr;
+
+ FD_ZERO (&rset);
+ FD_SET (sock, &rset);
+ tv.tv_sec = 0;
+ tv.tv_usec = 0;
+ r = select (sock+1, &rset, NULL, NULL, &tv);
+ if (r == -1) {
+ perror ("select");
+ return 0;
+ }
+ if (r == 0)
+ return 0;
+
+ /* Read the message from the daemon. */
+ r = xread (sock, buf, sizeof buf);
+ if (r == -1)
+ return 0;
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_DECODE);
+ xdr_u_int (&xdr, &flag);
+ xdr_destroy (&xdr);
+
+ if (flag != GUESTFS_CANCEL_FLAG) {
+ fprintf (stderr, "check_for_library_cancellation: read 0x%x from library, expected 0x%x\n",
+ flag, GUESTFS_CANCEL_FLAG);
+ return 0;
+ }
+
+ return 1;
+}
+
+int
+send_file_end (int cancel)
+{
+ guestfs_chunk chunk;
+
+ chunk.cancel = cancel;
+ chunk.data.data_len = 0;
+ chunk.data.data_val = NULL;
+ return send_chunk (&chunk);
+}
+
+static int
+send_chunk (const guestfs_chunk *chunk)
+{
+ char buf[GUESTFS_MAX_CHUNK_SIZE + 48];
+ char lenbuf[4];
+ XDR xdr;
+ uint32_t len;
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
+ if (!xdr_guestfs_chunk (&xdr, (guestfs_chunk *) chunk)) {
+ fprintf (stderr, "send_chunk: failed to encode chunk\n");
+ xdr_destroy (&xdr);
+ return -1;
+ }
+
+ len = xdr_getpos (&xdr);
+ xdr_destroy (&xdr);
+
+ xdrmem_create (&xdr, lenbuf, 4, XDR_ENCODE);
+ xdr_u_int (&xdr, &len);
+ xdr_destroy (&xdr);
+
+ int err = (xwrite (sock, lenbuf, 4) == 0
+ && xwrite (sock, buf, len) == 0 ? 0 : -1);
+ if (err) {
+ fprintf (stderr, "send_chunk: write failed\n");
+ exit (EXIT_FAILURE);
+ }
+
+ return err;
+}
+
+/* Initial delay before sending notification messages, and
+ * the period at which we send them thereafter. These times
+ * are in microseconds.
+ */
+#define NOTIFICATION_INITIAL_DELAY 2000000
+#define NOTIFICATION_PERIOD 333333
+
+void
+notify_progress (uint64_t position, uint64_t total)
+{
+ struct timeval now_t;
+ gettimeofday (&now_t, NULL);
+
+ /* Always send a notification at 100%. This simplifies callers by
+ * allowing them to 'finish' the progress bar at 100% without
+ * needing special code.
+ */
+ if (count_progress > 0 && position == total)
+ goto send;
+
+ /* Calculate time in microseconds since the last progress message
+ * was sent out (or since the start of the call).
+ */
+ int64_t last_us, now_us, elapsed_us;
+ last_us =
+ (int64_t) last_progress_t.tv_sec * 1000000 + last_progress_t.tv_usec;
+ now_us = (int64_t) now_t.tv_sec * 1000000 + now_t.tv_usec;
+ elapsed_us = now_us - last_us;
+
+ /* Rate limit. */
+ if ((count_progress == 0 && elapsed_us < NOTIFICATION_INITIAL_DELAY) ||
+ (count_progress > 0 && elapsed_us < NOTIFICATION_PERIOD))
+ return;
+
+ send:
+ /* We're going to send a message now ... */
+ count_progress++;
+ last_progress_t = now_t;
+
+ /* Send the header word. */
+ XDR xdr;
+ char buf[128];
+ uint32_t i = GUESTFS_PROGRESS_FLAG;
+ size_t len;
+ xdrmem_create (&xdr, buf, 4, XDR_ENCODE);
+ xdr_u_int (&xdr, &i);
+ xdr_destroy (&xdr);
+
+ if (xwrite (sock, buf, 4) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (EXIT_FAILURE);
+ }
+
+ guestfs_progress message = {
+ .proc = proc_nr,
+ .serial = serial,
+ .position = position,
+ .total = total,
+ };
+
+ xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
+ if (!xdr_guestfs_progress (&xdr, &message)) {
+ fprintf (stderr, "xdr_guestfs_progress: failed to encode message\n");
+ xdr_destroy (&xdr);
+ return;
+ }
+ len = xdr_getpos (&xdr);
+ xdr_destroy (&xdr);
+
+ if (xwrite (sock, buf, len) == -1) {
+ fprintf (stderr, "xwrite failed\n");
+ exit (EXIT_FAILURE);
+ }
}
git.annexia.org / libguestfs.git / blobdiff