/*
This file is part of GNUnet.
- (C) 2011, 2012 Christian Grothoff
+ Copyright (C) 2011, 2012 Christian Grothoff
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
* @file util/helper.c
- * @brief API for dealing with (SUID) helper processes that communicate via GNUNET_MessageHeaders on stdin/stdout
+ * @brief API for dealing with (SUID) helper processes that communicate via
+ * GNUNET_MessageHeaders on stdin/stdout
* @author Philipp Toelke
* @author Christian Grothoff
*/
* Message to transmit (allocated at the end of this struct)
*/
const struct GNUNET_MessageHeader *msg;
-
+
/**
* The handle to a helper process.
*/
struct GNUNET_HELPER_Handle *h;
-
+
/**
* Function to call upon completion.
*/
* PipeHandle to receive data from the helper
*/
struct GNUNET_DISK_PipeHandle *helper_in;
-
+
/**
* PipeHandle to send data to the helper
*/
struct GNUNET_DISK_PipeHandle *helper_out;
-
+
/**
* FileHandle to receive data from the helper
*/
const struct GNUNET_DISK_FileHandle *fh_from_helper;
-
+
/**
* FileHandle to send data to the helper
*/
const struct GNUNET_DISK_FileHandle *fh_to_helper;
-
+
/**
* The process id of the helper
*/
/**
* Binary to run.
*/
- const char *binary_name;
+ char *binary_name;
/**
* NULL-terminated list of command-line arguments.
*/
- char *const *binary_argv;
-
+ char **binary_argv;
+
/**
* Task to read from the helper.
*/
- GNUNET_SCHEDULER_TaskIdentifier read_task;
+ struct GNUNET_SCHEDULER_Task *read_task;
/**
* Task to read from the helper.
*/
- GNUNET_SCHEDULER_TaskIdentifier write_task;
+ struct GNUNET_SCHEDULER_Task *write_task;
/**
* Restart task.
*/
- GNUNET_SCHEDULER_TaskIdentifier restart_task;
+ struct GNUNET_SCHEDULER_Task *restart_task;
/**
* Does the helper support the use of a control pipe for signalling?
*/
int with_control_pipe;
+ /**
+ * Count start attempts to increase linear back off
+ */
+ unsigned int retry_back_off;
};
/**
- * Stop the helper process, we're closing down or had an error.
+ * Sends termination signal to the helper process. The helper process is not
+ * reaped; call GNUNET_HELPER_wait() for reaping the dead helper process.
*
- * @param h handle to the helper process
+ * @param h the helper handle
+ * @param soft_kill if GNUNET_YES, signals termination by closing the helper's
+ * stdin; GNUNET_NO to signal termination by sending SIGTERM to helper
+ * @return #GNUNET_OK on success; #GNUNET_SYSERR on error
*/
-static void
-stop_helper (struct GNUNET_HELPER_Handle *h)
+int
+GNUNET_HELPER_kill (struct GNUNET_HELPER_Handle *h,
+ int soft_kill)
{
struct GNUNET_HELPER_SendHandle *sh;
+ int ret;
- if (NULL != h->helper_proc)
+ while (NULL != (sh = h->sh_head))
{
- GNUNET_break (0 == GNUNET_OS_process_kill (h->helper_proc, SIGTERM));
- GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (h->helper_proc));
- GNUNET_OS_process_destroy (h->helper_proc);
- h->helper_proc = NULL;
+ GNUNET_CONTAINER_DLL_remove (h->sh_head,
+ h->sh_tail,
+ sh);
+ if (NULL != sh->cont)
+ sh->cont (sh->cont_cls, GNUNET_NO);
+ GNUNET_free (sh);
}
- if (GNUNET_SCHEDULER_NO_TASK != h->restart_task)
+ if (NULL != h->restart_task)
{
GNUNET_SCHEDULER_cancel (h->restart_task);
- h->restart_task = GNUNET_SCHEDULER_NO_TASK;
+ h->restart_task = NULL;
}
- if (GNUNET_SCHEDULER_NO_TASK != h->read_task)
+ if (NULL != h->read_task)
{
GNUNET_SCHEDULER_cancel (h->read_task);
- h->read_task = GNUNET_SCHEDULER_NO_TASK;
+ h->read_task = NULL;
}
- if (GNUNET_SCHEDULER_NO_TASK != h->write_task)
+ if (NULL == h->helper_proc)
+ return GNUNET_SYSERR;
+ if (GNUNET_YES == soft_kill)
+ {
+ /* soft-kill only possible with pipes */
+ GNUNET_assert (NULL != h->helper_in);
+ ret = GNUNET_DISK_pipe_close (h->helper_in);
+ h->helper_in = NULL;
+ h->fh_to_helper = NULL;
+ return ret;
+ }
+ if (0 != GNUNET_OS_process_kill (h->helper_proc, GNUNET_TERM_SIG))
+ return GNUNET_SYSERR;
+ return GNUNET_OK;
+}
+
+
+/**
+ * Reap the helper process. This call is blocking(!). The helper process
+ * should either be sent a termination signal before or should be dead before
+ * calling this function
+ *
+ * @param h the helper handle
+ * @return #GNUNET_OK on success; #GNUNET_SYSERR on error
+ */
+int
+GNUNET_HELPER_wait (struct GNUNET_HELPER_Handle *h)
+{
+ struct GNUNET_HELPER_SendHandle *sh;
+ int ret;
+
+ ret = GNUNET_SYSERR;
+ if (NULL != h->helper_proc)
+ {
+ ret = GNUNET_OS_process_wait (h->helper_proc);
+ GNUNET_OS_process_destroy (h->helper_proc);
+ h->helper_proc = NULL;
+ }
+ if (NULL != h->read_task)
+ {
+ GNUNET_SCHEDULER_cancel (h->read_task);
+ h->read_task = NULL;
+ }
+ if (NULL != h->write_task)
{
GNUNET_SCHEDULER_cancel (h->write_task);
- h->write_task = GNUNET_SCHEDULER_NO_TASK;
+ h->write_task = NULL;
}
if (NULL != h->helper_in)
{
GNUNET_free (sh);
}
/* purge MST buffer */
- (void) GNUNET_SERVER_mst_receive (h->mst, NULL, NULL, 0, GNUNET_YES, GNUNET_NO);
+ if (NULL != h->mst)
+ (void) GNUNET_SERVER_mst_receive (h->mst, NULL, NULL, 0, GNUNET_YES, GNUNET_NO);
+ return ret;
+}
+
+
+/**
+ * Stop the helper process, we're closing down or had an error.
+ *
+ * @param h handle to the helper process
+ * @param soft_kill if #GNUNET_YES, signals termination by closing the helper's
+ * stdin; #GNUNET_NO to signal termination by sending SIGTERM to helper
+ */
+static void
+stop_helper (struct GNUNET_HELPER_Handle *h,
+ int soft_kill)
+{
+ if (NULL != h->restart_task)
+ {
+ GNUNET_SCHEDULER_cancel (h->restart_task);
+ h->restart_task = NULL;
+ }
+ else
+ {
+ GNUNET_break (GNUNET_OK == GNUNET_HELPER_kill (h, soft_kill));
+ GNUNET_break (GNUNET_OK == GNUNET_HELPER_wait (h));
+ }
}
* Restart the helper process.
*
* @param cls handle to the helper process
- * @param tc scheduler context
*/
static void
-restart_task (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc);
+restart_task (void *cls);
/**
* Read from the helper-process
*
* @param cls handle to the helper process
- * @param tc scheduler context
*/
static void
-helper_read (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
+helper_read (void *cls)
{
struct GNUNET_HELPER_Handle *h = cls;
char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE] GNUNET_ALIGN;
ssize_t t;
- h->read_task = GNUNET_SCHEDULER_NO_TASK;
- if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
- {
- /* try again */
- h->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
- h->fh_from_helper, &helper_read, h);
- return;
- }
+ h->read_task = NULL;
t = GNUNET_DISK_file_read (h->fh_from_helper, &buf, sizeof (buf));
if (t < 0)
{
if (NULL != h->exp_cb)
{
h->exp_cb (h->cb_cls);
- GNUNET_HELPER_stop (h);
+ GNUNET_HELPER_stop (h, GNUNET_NO);
return;
}
- stop_helper (h);
+ stop_helper (h, GNUNET_NO);
/* Restart the helper */
- h->restart_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &restart_task, h);
+ h->restart_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
+ h->retry_back_off),
+ &restart_task, h);
return;
}
if (0 == t)
{
- /* this happens if the helper is shut down via a
+ /* this happens if the helper is shut down via a
signal, so it is not a "hard" error */
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("Got 0 bytes from helper `%s' (EOF)\n"),
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Got 0 bytes from helper `%s' (EOF)\n",
h->binary_name);
if (NULL != h->exp_cb)
{
h->exp_cb (h->cb_cls);
- GNUNET_HELPER_stop (h);
+ GNUNET_HELPER_stop (h, GNUNET_NO);
return;
}
- stop_helper (h);
+ stop_helper (h, GNUNET_NO);
/* Restart the helper */
- h->restart_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
- &restart_task, h);
+ h->restart_task
+ = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
+ h->retry_back_off),
+ &restart_task, h);
return;
}
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("Got %u bytes from helper `%s'\n"),
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Got %u bytes from helper `%s'\n",
(unsigned int) t,
h->binary_name);
h->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
- h->fh_from_helper, &helper_read, h);
+ h->fh_from_helper,
+ &helper_read, h);
if (GNUNET_SYSERR ==
- GNUNET_SERVER_mst_receive (h->mst, NULL, buf, t, GNUNET_NO, GNUNET_NO))
+ GNUNET_SERVER_mst_receive (h->mst,
+ NULL,
+ buf, t,
+ GNUNET_NO, GNUNET_NO))
{
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
_("Failed to parse inbound message from helper `%s'\n"),
h->binary_name);
if (NULL != h->exp_cb)
{
h->exp_cb (h->cb_cls);
- GNUNET_HELPER_stop (h);
+ GNUNET_HELPER_stop (h, GNUNET_NO);
return;
- }
- stop_helper (h);
+ }
+ stop_helper (h, GNUNET_NO);
/* Restart the helper */
- h->restart_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
- &restart_task, h);
+ h->restart_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS,
+ h->retry_back_off),
+ &restart_task, h);
return;
}
}
if ( (h->helper_in == NULL) || (h->helper_out == NULL))
{
/* out of file descriptors? try again later... */
- stop_helper (h);
+ stop_helper (h, GNUNET_NO);
h->restart_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
- &restart_task, h);
+ GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS,
+ h->retry_back_off),
+ &restart_task, h);
return;
}
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("Starting HELPER process `%s'\n"),
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Starting HELPER process `%s'\n",
h->binary_name);
h->fh_from_helper =
GNUNET_DISK_pipe_handle (h->helper_out, GNUNET_DISK_PIPE_END_READ);
h->fh_to_helper =
GNUNET_DISK_pipe_handle (h->helper_in, GNUNET_DISK_PIPE_END_WRITE);
h->helper_proc =
- GNUNET_OS_start_process_vap (h->with_control_pipe, GNUNET_OS_INHERIT_STD_ERR,
- h->helper_in, h->helper_out,
+ GNUNET_OS_start_process_vap (h->with_control_pipe, GNUNET_OS_INHERIT_STD_ERR,
+ h->helper_in, h->helper_out, NULL,
h->binary_name,
h->binary_argv);
if (NULL == h->helper_proc)
{
/* failed to start process? try again later... */
- stop_helper (h);
- h->restart_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
- &restart_task, h);
+ stop_helper (h, GNUNET_NO);
+ h->restart_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS,
+ h->retry_back_off),
+ &restart_task, h);
return;
}
GNUNET_DISK_pipe_close_end (h->helper_out, GNUNET_DISK_PIPE_END_WRITE);
GNUNET_DISK_pipe_close_end (h->helper_in, GNUNET_DISK_PIPE_END_READ);
- h->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
- h->fh_from_helper,
- &helper_read,
- h);
+ if (NULL != h->mst)
+ h->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
+ h->fh_from_helper,
+ &helper_read,
+ h);
}
* Restart the helper process.
*
* @param cls handle to the helper process
- * @param tc scheduler context
*/
static void
-restart_task (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
+restart_task (void *cls)
{
struct GNUNET_HELPER_Handle*h = cls;
- h->restart_task = GNUNET_SCHEDULER_NO_TASK;
+ h->restart_task = NULL;
+ h->retry_back_off++;
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Restarting helper with back-off %u\n",
+ h->retry_back_off);
start_helper (h);
}
GNUNET_HELPER_ExceptionCallback exp_cb,
void *cb_cls)
{
- struct GNUNET_HELPER_Handle*h;
+ struct GNUNET_HELPER_Handle *h;
+ unsigned int c;
- h = GNUNET_malloc (sizeof (struct GNUNET_HELPER_Handle));
+ h = GNUNET_new (struct GNUNET_HELPER_Handle);
h->with_control_pipe = with_control_pipe;
- h->binary_name = binary_name;
- h->binary_argv = binary_argv;
+ /* Lookup in libexec path only if we are starting gnunet helpers */
+ if (NULL != strstr (binary_name, "gnunet"))
+ h->binary_name = GNUNET_OS_get_libexec_binary_path (binary_name);
+ else
+ h->binary_name = GNUNET_strdup (binary_name);
+ for (c = 0; NULL != binary_argv[c]; c++);
+ h->binary_argv = GNUNET_malloc (sizeof (char *) * (c + 1));
+ for (c = 0; NULL != binary_argv[c]; c++)
+ h->binary_argv[c] = GNUNET_strdup (binary_argv[c]);
+ h->binary_argv[c] = NULL;
h->cb_cls = cb_cls;
- h->mst = GNUNET_SERVER_mst_create (cb, h->cb_cls);
+ if (NULL != cb)
+ h->mst = GNUNET_SERVER_mst_create (cb, h->cb_cls);
h->exp_cb = exp_cb;
+ h->retry_back_off = 0;
start_helper (h);
return h;
}
/**
- * @brief Kills the helper, closes the pipe and frees the h
+ * Free's the resources occupied by the helper handle
*
- * @param h h to helper to stop
+ * @param h the helper handle to free
*/
void
-GNUNET_HELPER_stop (struct GNUNET_HELPER_Handle *h)
+GNUNET_HELPER_destroy (struct GNUNET_HELPER_Handle *h)
{
+ unsigned int c;
struct GNUNET_HELPER_SendHandle *sh;
- h->exp_cb = NULL;
- /* signal pending writes that we were stopped */
+ if (NULL != h->write_task)
+ {
+ GNUNET_SCHEDULER_cancel (h->write_task);
+ h->write_task = NULL;
+ }
+ GNUNET_assert (NULL == h->read_task);
+ GNUNET_assert (NULL == h->restart_task);
while (NULL != (sh = h->sh_head))
{
GNUNET_CONTAINER_DLL_remove (h->sh_head,
sh->cont (sh->cont_cls, GNUNET_SYSERR);
GNUNET_free (sh);
}
- stop_helper (h);
- GNUNET_SERVER_mst_destroy (h->mst);
+ if (NULL != h->mst)
+ GNUNET_SERVER_mst_destroy (h->mst);
+ GNUNET_free (h->binary_name);
+ for (c = 0; h->binary_argv[c] != NULL; c++)
+ GNUNET_free (h->binary_argv[c]);
+ GNUNET_free (h->binary_argv);
GNUNET_free (h);
}
+/**
+ * Kills the helper, closes the pipe and frees the handle
+ *
+ * @param h handle to helper to stop
+ * @param soft_kill if #GNUNET_YES, signals termination by closing the helper's
+ * stdin; #GNUNET_NO to signal termination by sending SIGTERM to helper
+ */
+void
+GNUNET_HELPER_stop (struct GNUNET_HELPER_Handle *h,
+ int soft_kill)
+{
+ h->exp_cb = NULL;
+ stop_helper (h, soft_kill);
+ GNUNET_HELPER_destroy (h);
+}
+
+
/**
* Write to the helper-process
*
* @param cls handle to the helper process
- * @param tc scheduler context
*/
static void
-helper_write (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
+helper_write (void *cls)
{
struct GNUNET_HELPER_Handle *h = cls;
struct GNUNET_HELPER_SendHandle *sh;
const char *buf;
ssize_t t;
- h->write_task = GNUNET_SCHEDULER_NO_TASK;
- if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
- {
- /* try again */
- h->write_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
- h->fh_to_helper, &helper_write, h);
- return;
- }
+ h->write_task = NULL;
if (NULL == (sh = h->sh_head))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Helper write had no work!\n");
return; /* how did this happen? */
+ }
buf = (const char*) sh->msg;
- t = GNUNET_DISK_file_write (h->fh_to_helper, &buf[sh->wpos], ntohs (sh->msg->size) - sh->wpos);
- if (t <= 0)
+ t = GNUNET_DISK_file_write (h->fh_to_helper,
+ &buf[sh->wpos],
+ ntohs (sh->msg->size) - sh->wpos);
+ if (-1 == t)
{
/* On write-error, restart the helper */
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Error writing to `%s': %s\n"),
+ _("Error writing to `%s': %s\n"),
h->binary_name,
STRERROR (errno));
- stop_helper (h);
+ if (NULL != h->exp_cb)
+ {
+ h->exp_cb (h->cb_cls);
+ GNUNET_HELPER_stop (h, GNUNET_NO);
+ return;
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Stopping and restarting helper task!\n");
+ stop_helper (h, GNUNET_NO);
/* Restart the helper */
- h->restart_task =
- GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
- &restart_task, h);
+ h->restart_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS,
+ h->retry_back_off),
+ &restart_task, h);
return;
}
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Transmitted %u bytes to %s\n",
+ (unsigned int) t,
+ h->binary_name);
sh->wpos += t;
if (sh->wpos == ntohs (sh->msg->size))
{
}
if (NULL != h->sh_head)
h->write_task = GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
- h->fh_to_helper,
- &helper_write,
+ h->fh_to_helper,
+ &helper_write,
h);
}
* @param h helper to send message to
* @param msg message to send
* @param can_drop can the message be dropped if there is already one in the queue?
- * @param cont continuation to run once the message is out (PREREQ_DONE on succees, CANCEL
- * if the helper process died, NULL during GNUNET_HELPER_stop).
- * @param cont_cls closure for 'cont'
- * @return NULL if the message was dropped,
+ * @param cont continuation to run once the message is out (#GNUNET_OK on succees, #GNUNET_NO
+ * if the helper process died, #GNUNET_SYSERR during #GNUNET_HELPER_destroy).
+ * @param cont_cls closure for @a cont
+ * @return NULL if the message was dropped,
* otherwise handle to cancel *cont* (actual transmission may
* not be abortable)
*/
struct GNUNET_HELPER_SendHandle *
-GNUNET_HELPER_send (struct GNUNET_HELPER_Handle *h,
+GNUNET_HELPER_send (struct GNUNET_HELPER_Handle *h,
const struct GNUNET_MessageHeader *msg,
int can_drop,
GNUNET_HELPER_Continuation cont,
mlen = ntohs (msg->size);
sh = GNUNET_malloc (sizeof (struct GNUNET_HELPER_SendHandle) + mlen);
sh->msg = (const struct GNUNET_MessageHeader*) &sh[1];
- memcpy (&sh[1], msg, mlen);
+ GNUNET_memcpy (&sh[1], msg, mlen);
sh->h = h;
sh->cont = cont;
sh->cont_cls = cont_cls;
GNUNET_CONTAINER_DLL_insert_tail (h->sh_head,
h->sh_tail,
sh);
- if (GNUNET_SCHEDULER_NO_TASK == h->write_task)
+ if (NULL == h->write_task)
h->write_task = GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
- h->fh_to_helper,
- &helper_write,
+ h->fh_to_helper,
+ &helper_write,
h);
-
+
return sh;
}
/**
- * Cancel a 'send' operation. If possible, transmitting the
+ * Cancel a #GNUNET_HELPER_send operation. If possible, transmitting the
* message is also aborted, but at least 'cont' won't be
* called.
*
if (0 == sh->wpos)
{
GNUNET_CONTAINER_DLL_remove (h->sh_head, h->sh_tail, sh);
+ GNUNET_free (sh);
if (NULL == h->sh_head)
{
GNUNET_SCHEDULER_cancel (h->write_task);
- h->write_task = GNUNET_SCHEDULER_NO_TASK;
+ h->write_task = NULL;
}
- GNUNET_free (sh);
}
}