tor-android/external/badvpn_dns/ncd/modules/command_template.c

219 lines
7.0 KiB
C

/**
* @file command_template.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <misc/debug.h>
#include <ncd/modules/command_template.h>
#define STATE_ADDING_LOCK 1
#define STATE_ADDING 2
#define STATE_ADDING_NEED_DELETE 3
#define STATE_DONE 4
#define STATE_DELETING_LOCK 5
#define STATE_DELETING 6
static void lock_handler (command_template_instance *o);
static void process_handler (command_template_instance *o, int normally, uint8_t normally_exit_status);
static void free_template (command_template_instance *o, int is_error);
static void lock_handler (command_template_instance *o)
{
ASSERT(o->state == STATE_ADDING_LOCK || o->state == STATE_DELETING_LOCK)
ASSERT(!(o->state == STATE_ADDING_LOCK) || o->do_exec)
ASSERT(!(o->state == STATE_DELETING_LOCK) || o->undo_exec)
if (o->state == STATE_ADDING_LOCK) {
// start process
if (!BProcess_Init(&o->process, o->i->params->iparams->manager, (BProcess_handler)process_handler, o, o->do_exec, CmdLine_Get(&o->do_cmdline), NULL)) {
NCDModuleInst_Backend_Log(o->i, o->blog_channel, BLOG_ERROR, "BProcess_Init failed");
free_template(o, 1);
return;
}
// set state
o->state = STATE_ADDING;
} else {
// start process
if (!BProcess_Init(&o->process, o->i->params->iparams->manager, (BProcess_handler)process_handler, o, o->undo_exec, CmdLine_Get(&o->undo_cmdline), NULL)) {
NCDModuleInst_Backend_Log(o->i, o->blog_channel, BLOG_ERROR, "BProcess_Init failed");
free_template(o, 1);
return;
}
// set state
o->state = STATE_DELETING;
}
}
static void process_handler (command_template_instance *o, int normally, uint8_t normally_exit_status)
{
ASSERT(o->state == STATE_ADDING || o->state == STATE_ADDING_NEED_DELETE || o->state == STATE_DELETING)
// release lock
BEventLockJob_Release(&o->elock_job);
// free process
BProcess_Free(&o->process);
if (!normally || normally_exit_status != 0) {
NCDModuleInst_Backend_Log(o->i, o->blog_channel, BLOG_ERROR, "command failed");
free_template(o, 1);
return;
}
switch (o->state) {
case STATE_ADDING: {
// set state
o->state = STATE_DONE;
// signal up
NCDModuleInst_Backend_Up(o->i);
} break;
case STATE_ADDING_NEED_DELETE: {
if (o->undo_exec) {
// wait for lock
BEventLockJob_Wait(&o->elock_job);
// set state
o->state = STATE_DELETING_LOCK;
} else {
free_template(o, 0);
return;
}
} break;
case STATE_DELETING: {
// finish
free_template(o, 0);
return;
} break;
}
}
void command_template_new (command_template_instance *o, NCDModuleInst *i, const struct NCDModuleInst_new_params *params, command_template_build_cmdline build_cmdline, command_template_free_func free_func, void *user, int blog_channel, BEventLock *elock)
{
// init arguments
o->i = i;
o->free_func = free_func;
o->user = user;
o->blog_channel = blog_channel;
// build do command
if (!build_cmdline(o->i, params->args, 0, &o->do_exec, &o->do_cmdline)) {
NCDModuleInst_Backend_Log(o->i, o->blog_channel, BLOG_ERROR, "build_cmdline do callback failed");
goto fail0;
}
// build undo command
if (!build_cmdline(o->i, params->args, 1, &o->undo_exec, &o->undo_cmdline)) {
NCDModuleInst_Backend_Log(o->i, o->blog_channel, BLOG_ERROR, "build_cmdline undo callback failed");
goto fail1;
}
// init lock job
BEventLockJob_Init(&o->elock_job, elock, (BEventLock_handler)lock_handler, o);
if (o->do_exec) {
// wait for lock
BEventLockJob_Wait(&o->elock_job);
// set state
o->state = STATE_ADDING_LOCK;
} else {
// set state
o->state = STATE_DONE;
// signal up
NCDModuleInst_Backend_Up(o->i);
}
return;
fail1:
if (o->do_exec) {
free(o->do_exec);
CmdLine_Free(&o->do_cmdline);
}
fail0:
o->free_func(o->user, 1);
}
static void free_template (command_template_instance *o, int is_error)
{
// free lock job
BEventLockJob_Free(&o->elock_job);
// free undo command
if (o->undo_exec) {
free(o->undo_exec);
CmdLine_Free(&o->undo_cmdline);
}
// free do command
if (o->do_exec) {
free(o->do_exec);
CmdLine_Free(&o->do_cmdline);
}
// call free function
o->free_func(o->user, is_error);
}
void command_template_die (command_template_instance *o)
{
ASSERT(o->state == STATE_ADDING_LOCK || o->state == STATE_ADDING || o->state == STATE_DONE)
switch (o->state) {
case STATE_ADDING_LOCK: {
free_template(o, 0);
return;
} break;
case STATE_ADDING: {
// set state
o->state = STATE_ADDING_NEED_DELETE;
} break;
case STATE_DONE: {
if (o->undo_exec) {
// wait for lock
BEventLockJob_Wait(&o->elock_job);
// set state
o->state = STATE_DELETING_LOCK;
} else {
free_template(o, 0);
return;
}
} break;
}
}