/**
* mds — A micro-display server
* Copyright © 2014, 2015, 2016 Mattias Andrée (maandree@member.fsf.org)
*
* 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
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "reexec.h"
#include "util.h"
#include "globals.h"
#include "slave.h"
#include <libmdsserver/macros.h>
#include <libmdsserver/hash-help.h>
#include <libmdsserver/client-list.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
/**
* Calculate the number of bytes that will be stored by `marshal_server`
*
* On failure the program should `abort()` or exit by other means.
* However it should not be possible for this function to fail.
*
* @return The number of bytes that will be stored by `marshal_server`
*/
size_t
marshal_server_size(void)
{
size_t i, rc = 2 * sizeof(int) + sizeof(uint32_t) + 4 * sizeof(size_t);
hash_entry_t *entry;
ssize_t node;
char *command;
size_t len;
client_list_t *list;
slave_t *slave;
rc += mds_message_marshal_size(&received);
rc += linked_list_marshal_size(&slave_list);
foreach_hash_table_entry (reg_table, i, entry) {
command = (void *)entry->key;
len = strlen(command) + 1;
list = (void *)entry->value;
rc += len + sizeof(size_t) + client_list_marshal_size(list);
}
foreach_linked_list_node (slave_list, node) {
slave = (void *)slave_list.values[node];
rc += slave_marshal_size(slave);
}
return rc;
}
/**
* Marshal server implementation specific data into a buffer
*
* @param state_buf The buffer for the marshalled data
* @return Non-zero on error
*/
int
marshal_server(char *state_buf)
{
size_t i, n = mds_message_marshal_size(&received);
hash_entry_t *entry;
ssize_t node;
char *command;
size_t len;
client_list_t *list;
slave_t *slave;
buf_set_next(state_buf, int, MDS_REGISTRY_VARS_VERSION);
buf_set_next(state_buf, int, connected);
buf_set_next(state_buf, uint32_t, message_id);
buf_set_next(state_buf, size_t, n);
mds_message_marshal(&received, state_buf);
state_buf += n / sizeof(char);
buf_set_next(state_buf, size_t, reg_table.capacity);
buf_set_next(state_buf, size_t, reg_table.size);
foreach_hash_table_entry (reg_table, i, entry) {
command = (void *)(entry->key);
len = strlen(command) + 1;
list = (void *)(entry->value);
memcpy(state_buf, command, len * sizeof(char));
state_buf += len;
n = client_list_marshal_size(list);
buf_set_next(state_buf, size_t, n);
client_list_marshal(list, state_buf);
state_buf += n / sizeof(char);
}
n = linked_list_marshal_size(&slave_list);
buf_set_next(state_buf, size_t, n);
linked_list_marshal(&slave_list, state_buf);
state_buf += n / sizeof(char);
foreach_linked_list_node (slave_list, node) {
slave = (void *)(slave_list.values[node]);
state_buf += slave_marshal(slave, state_buf) / sizeof(char);
slave_destroy(slave);
}
hash_table_destroy(®_table, (free_func *)reg_table_free_key, (free_func *)reg_table_free_value);
mds_message_destroy(&received);
linked_list_destroy(&slave_list);
return 0;
}
/**
* Unmarshal server implementation specific data and update the servers state accordingly
*
* On critical failure the program should `abort()` or exit by other means.
* That is, do not let `reexec_failure_recover` run successfully, if it unrecoverable
* error has occurred or one severe enough that it is better to simply respawn.
*
* @param state_buf The marshalled data that as not been read already
* @return Non-zero on error
*/
int
unmarshal_server(char *state_buf)
{
char *command;
client_list_t *list;
slave_t *slave;
size_t i, n, m;
ssize_t node;
int stage = 0;
/* buf_get_next(state_buf, int, MDS_REGISTRY_VARS_VERSION); */
buf_next(state_buf, int, 1);
buf_get_next(state_buf, int, connected);
buf_get_next(state_buf, uint32_t, message_id);
buf_get_next(state_buf, size_t, n);
fail_if (mds_message_unmarshal(&received, state_buf));
state_buf += n / sizeof(char);
stage = 1;
buf_get_next(state_buf, size_t, n);
fail_if (hash_table_create_tuned(®_table, n));
buf_get_next(state_buf, size_t, n);
for (i = 0; i < n; i++) {
stage = 1;
fail_if (xstrdup(command, state_buf));
state_buf += strlen(command) + 1;
stage = 2;
fail_if (xmalloc(list, 1, client_list_t));
buf_get_next(state_buf, size_t, m);
stage = 3;
fail_if (client_list_unmarshal(list, state_buf));
state_buf += m / sizeof(char);
hash_table_put(®_table, (size_t)(void *)command, (size_t)(void *)list);
fail_if (errno);
}
command = NULL;
stage = 4;
reg_table.key_comparator = (compare_func*)string_comparator;
reg_table.hasher = (hash_func*)string_hash;
buf_get_next(state_buf, size_t, n);
fail_if (linked_list_unmarshal(&slave_list, state_buf));
state_buf += n / sizeof(char);
foreach_linked_list_node (slave_list, node) {
stage = 5;
fail_if (xmalloc(slave, 1, slave_t));
stage = 6;
fail_if ((n = slave_unmarshal(slave, state_buf)) == 0);
state_buf += n / sizeof(char);
slave_list.values[node] = (size_t)(void *)slave;
}
foreach_linked_list_node (slave_list, node) {
slave = (slave_t *)(void *)(slave_list.values[node]);
fail_if (start_created_slave(slave));
}
return 0;
fail:
xperror(*argv);
mds_message_destroy(&received);
if (stage >= 1)
hash_table_destroy(®_table, (free_func *)reg_table_free_key, (free_func *)reg_table_free_value);
if (stage >= 2) free(command);
if (stage >= 3) client_list_destroy(list), free(list);
if (stage >= 5) linked_list_destroy(&slave_list);
if (stage >= 6) slave_destroy(slave), free(slave);
abort();
return -1;
}
/**
* Attempt to recover from a re-exec failure that has been
* detected after the server successfully updated it execution image
*
* @return Non-zero on error
*/
int __attribute__((const))
reexec_failure_recover(void)
{
return -1;
}
