BadVPN – Rev 1
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/**
* @file runonce.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.
*
* @section DESCRIPTION
*
* Imperative program execution module. On initialization, starts the process.
* Goes to UP state when the process terminates. When requested to die, waits for
* the process to terminate if it's running, optionally sending SIGTERM.
*
* Synopsis: runonce(list(string) cmd, [list opts])
* Arguments:
* cmd - Command to run on startup. The first element is the full path
* to the executable, other elements are command line arguments (excluding
* the zeroth argument).
* opts - Map of options:
* "term_on_deinit":"true" - If we get a deinit request while the process is
* running, send it SIGTERM.
* "keep_stdout":"true" - Start the program with the same stdout as the NCD process.
* "keep_stderr":"true" - Start the program with the same stderr as the NCD process.
* "do_setsid":"true" - Call setsid() in the child before exec. This is needed to
* start the 'agetty' program.
* "username":username_string - Start the process under the permissions of the
* specified user.
* Variables:
* string exit_status - if the program exited normally, the non-negative exit code, otherwise -1
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <misc/cmdline.h>
#include <misc/strdup.h>
#include <system/BProcess.h>
#include <ncd/extra/NCDBProcessOpts.h>
#include <ncd/module_common.h>
#include <generated/blog_channel_ncd_runonce.h>
#define STATE_RUNNING 1
#define STATE_RUNNING_DIE 2
#define STATE_FINISHED 3
struct instance {
NCDModuleInst *i;
int term_on_deinit;
int state;
BProcess process;
int exit_status;
};
static void instance_free (struct instance *o);
static int build_cmdline (NCDModuleInst *i, NCDValRef cmd_arg, char **exec, CmdLine *cl)
{
ASSERT(!NCDVal_IsInvalid(cmd_arg))
if (!NCDVal_IsList(cmd_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
size_t count = NCDVal_ListCount(cmd_arg);
// read exec
if (count == 0) {
ModuleLog(i, BLOG_ERROR, "missing executable name");
goto fail0;
}
NCDValRef exec_arg = NCDVal_ListGet(cmd_arg, 0);
if (!NCDVal_IsStringNoNulls(exec_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
if (!(*exec = ncd_strdup(exec_arg))) {
ModuleLog(i, BLOG_ERROR, "strdup failed");
goto fail0;
}
// start cmdline
if (!CmdLine_Init(cl)) {
ModuleLog(i, BLOG_ERROR, "CmdLine_Init failed");
goto fail1;
}
// add header
if (!CmdLine_Append(cl, *exec)) {
ModuleLog(i, BLOG_ERROR, "CmdLine_Append failed");
goto fail2;
}
// add additional arguments
for (size_t j = 1; j < count; j++) {
NCDValRef arg = NCDVal_ListGet(cmd_arg, j);
if (!NCDVal_IsStringNoNulls(arg)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail2;
}
if (!CmdLine_AppendNoNullMr(cl, NCDVal_StringMemRef(arg))) {
ModuleLog(i, BLOG_ERROR, "CmdLine_AppendNoNull failed");
goto fail2;
}
}
// finish
if (!CmdLine_Finish(cl)) {
ModuleLog(i, BLOG_ERROR, "CmdLine_Finish failed");
goto fail2;
}
return 1;
fail2:
CmdLine_Free(cl);
fail1:
free(*exec);
fail0:
return 0;
}
static void process_handler (struct instance *o, int normally, uint8_t normally_exit_status)
{
ASSERT(o->state == STATE_RUNNING || o->state == STATE_RUNNING_DIE)
// free process
BProcess_Free(&o->process);
// if we were requested to die, die now
if (o->state == STATE_RUNNING_DIE) {
instance_free(o);
return;
}
// remember exit status
o->exit_status = (normally ? normally_exit_status : -1);
// set state
o->state = STATE_FINISHED;
// set up
NCDModuleInst_Backend_Up(o->i);
}
static int opts_func_unknown (void *user, NCDValRef key, NCDValRef val)
{
struct instance *o = user;
if (NCDVal_IsString(key) && NCDVal_StringEquals(key, "term_on_deinit")) {
if (!ncd_read_boolean(val, &o->term_on_deinit)) {
ModuleLog(o->i, BLOG_ERROR, "term_on_deinit: bad value");
return 0;
}
return 1;
}
return 0;
}
static void func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
struct instance *o = vo;
o->i = i;
// init arguments
o->term_on_deinit = 0;
// read arguments
NCDValRef cmd_arg;
NCDValRef opts_arg = NCDVal_NewInvalid();
if (!NCDVal_ListRead(params->args, 1, &cmd_arg) && !NCDVal_ListRead(params->args, 2, &cmd_arg, &opts_arg)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
NCDBProcessOpts opts;
// deprecated options format
if (!NCDVal_IsInvalid(opts_arg) && NCDVal_IsList(opts_arg)) {
int keep_stdout = 0;
int keep_stderr = 0;
int do_setsid = 0;
// read options
size_t count = NCDVal_IsInvalid(opts_arg) ? 0 : NCDVal_ListCount(opts_arg);
for (size_t j = 0; j < count; j++) {
NCDValRef opt = NCDVal_ListGet(opts_arg, j);
// read name
if (!NCDVal_IsString(opt)) {
ModuleLog(o->i, BLOG_ERROR, "wrong option name type");
goto fail0;
}
if (NCDVal_StringEquals(opt, "term_on_deinit")) {
o->term_on_deinit = 1;
}
else if (NCDVal_StringEquals(opt, "keep_stdout")) {
keep_stdout = 1;
}
else if (NCDVal_StringEquals(opt, "keep_stderr")) {
keep_stderr = 1;
}
else if (NCDVal_StringEquals(opt, "do_setsid")) {
do_setsid = 1;
}
else {
ModuleLog(o->i, BLOG_ERROR, "unknown option name");
goto fail0;
}
}
NCDBProcessOpts_InitOld(&opts, keep_stdout, keep_stderr, do_setsid);
} else {
if (!NCDBProcessOpts_Init(&opts, opts_arg, opts_func_unknown, o, i, BLOG_CURRENT_CHANNEL)) {
goto fail0;
}
}
// build cmdline
char *exec;
CmdLine cl;
if (!build_cmdline(o->i, cmd_arg, &exec, &cl)) {
NCDBProcessOpts_Free(&opts);
goto fail0;
}
// start process
struct BProcess_params p_params = NCDBProcessOpts_GetParams(&opts);
if (!BProcess_Init2(&o->process, o->i->params->iparams->manager, (BProcess_handler)process_handler, o, exec, CmdLine_Get(&cl), p_params)) {
ModuleLog(i, BLOG_ERROR, "BProcess_Init failed");
CmdLine_Free(&cl);
free(exec);
NCDBProcessOpts_Free(&opts);
goto fail0;
}
CmdLine_Free(&cl);
free(exec);
NCDBProcessOpts_Free(&opts);
// set state
o->state = STATE_RUNNING;
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static void instance_free (struct instance *o)
{
NCDModuleInst_Backend_Dead(o->i);
}
static void func_die (void *vo)
{
struct instance *o = vo;
ASSERT(o->state != STATE_RUNNING_DIE)
if (o->state == STATE_FINISHED) {
instance_free(o);
return;
}
// send SIGTERM if requested
if (o->term_on_deinit) {
BProcess_Terminate(&o->process);
}
o->state = STATE_RUNNING_DIE;
}
static int func_getvar (void *vo, const char *name, NCDValMem *mem, NCDValRef *out)
{
struct instance *o = vo;
ASSERT(o->state == STATE_FINISHED)
if (!strcmp(name, "exit_status")) {
char str[30];
snprintf(str, sizeof(str), "%d", o->exit_status);
*out = NCDVal_NewString(mem, str);
return 1;
}
return 0;
}
static struct NCDModule modules[] = {
{
.type = "runonce",
.func_new2 = func_new,
.func_die = func_die,
.func_getvar = func_getvar,
.alloc_size = sizeof(struct instance)
}, {
.type = NULL
}
};
const struct NCDModuleGroup ncdmodule_runonce = {
.modules = modules
};