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* New process-control RPC feature in clixon-lib.yang to manage processes

Browse source 
* This is an alternative to manage a clixon daemon via sudtemd, containerd or other
  * One important special case is starting the clixon-restconf daemon internally
  * This is how it works:
    * Register a process via `clixon_process_register(h, name, namespace, argv, argc)`
    * Use process-control RPC defined in clixon-lib.yang to start/stop/restart or query status on that process
  * Example code in the main example
This commit is contained in:
Olof hagsand 2020-12-15 14:43:01 +01:00
parent 8540820698
commit 22adc58187
19 changed files with 971 additions and 47 deletions
Download patch file Download diff file Expand all files Collapse all files

1
lib/clixon/clixon.h.in
View file

@ -77,6 +77,7 @@ extern "C" {
#include <clixon/clixon_yang_type.h>
#include <clixon/clixon_event.h>
#include <clixon/clixon_string.h>
#include <clixon/clixon_proc.h>
#include <clixon/clixon_file.h>
#include <clixon/clixon_xml.h>
#include <clixon/clixon_xml_sort.h>

51
lib/clixon/clixon_proc.h Normal file
View file

@ -0,0 +1,51 @@
/*
*
***** BEGIN LICENSE BLOCK *****
Copyright (C) 2009-2016 Olof Hagsand and Benny Holmgren
Copyright (C) 2017-2019 Olof Hagsand
Copyright (C) 2020 Olof Hagsand and Rubicon Communications, LLC(Netgate)
This file is part of CLIXON.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Alternatively, the contents of this file may be used under the terms of
the GNU General Public License Version 3 or later (the "GPL"),
in which case the provisions of the GPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of the GPL, and not to allow others to
use your version of this file under the terms of Apache License version 2,
indicate your decision by deleting the provisions above and replace them with
the notice and other provisions required by the GPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the Apache License version 2 or the GPL.
***** END LICENSE BLOCK *****
*/
#ifndef _CLIXON_PROC_H_
#define _CLIXON_PROC_H_
/*
* Prototypes
*/
int clixon_proc_run(char **argv, void (outcb)(char *), int doerr);
int clixon_proc_background(char **argv, char *netns, pid_t *pid);
int clixon_proc_daemon(char **argv, pid_t *pid);
int clixon_process_register(clicon_handle h, const char *name, const char *netns, char **argv, int argc);
int clixon_process_delete_all(clicon_handle h);
int clixon_process_operation(clicon_handle h, char *name, char *op, int *status);
#endif /* _CLIXON_PROC_H_ */

9
lib/clixon/clixon_sig.h
View file

@ -44,12 +44,13 @@ typedef void (*sigfn_t)(int);
/*
* Prototypes
*/
int set_signal(int signo, void (*handler)(int), void (**oldhandler)(int));
int set_signal(int signo, void (*handler)(int), void (**oldhandler)(int));
void clicon_signal_block(int);
void clicon_signal_unblock(int);
int pidfile_get(char *pidfile, pid_t *pid0);
int pidfile_write(char *pidfile);
int pidfile_zapold(pid_t pid);
int pidfile_get_fd(FILE *f, pid_t *pid0);
int pidfile_get(char *pidfile, pid_t *pid0);
int pidfile_write(char *pidfile);
int pidfile_zapold(pid_t pid);
#endif /* _CLIXON_SIG_H_ */

2
lib/src/Makefile.in
View file

@ -75,7 +75,7 @@ INCLUDES = -I. @INCLUDES@ -I$(top_srcdir)/lib/clixon -I$(top_srcdir)/include -I$
SRC = clixon_sig.c clixon_uid.c clixon_log.c clixon_err.c clixon_event.c \
clixon_string.c clixon_regex.c clixon_handle.c clixon_file.c \
clixon_xml.c clixon_xml_io.c clixon_xml_sort.c clixon_xml_map.c clixon_xml_vec.c \
clixon_xml_bind.c clixon_json.c \
clixon_xml_bind.c clixon_json.c clixon_proc.c \
clixon_yang.c clixon_yang_type.c clixon_yang_module.c clixon_yang_parse_lib.c \
clixon_yang_cardinality.c clixon_xml_changelog.c clixon_xml_nsctx.c \
clixon_path.c clixon_validate.c \

559
lib/src/clixon_proc.c Normal file
View file

@ -0,0 +1,559 @@
/*
*
***** BEGIN LICENSE BLOCK *****
Copyright (C) 2009-2016 Olof Hagsand and Benny Holmgren
Copyright (C) 2017-2019 Olof Hagsand
Copyright (C) 2020 Olof Hagsand and Rubicon Communications, LLC(Netgate)
This file is part of CLIXON.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Alternatively, the contents of this file may be used under the terms of
the GNU General Public License Version 3 or later (the "GPL"),
in which case the provisions of the GPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of the GPL, and not to allow others to
use your version of this file under the terms of Apache License version 2,
indicate your decision by deleting the provisions above and replace them with
the notice and other provisions required by the GPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the Apache License version 2 or the GPL.
***** END LICENSE BLOCK *****
* Processes daemons
*/
#ifdef HAVE_CONFIG_H
#include "clixon_config.h"
#endif
#ifdef HAVE_SETNS /* linux network namespaces */
#define _GNU_SOURCE
#endif
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <grp.h>
#include <fcntl.h>
#ifdef HAVE_SETNS /* linux network namespaces */
#include <sched.h> /* setns / unshare */
#endif
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/param.h>
#include <sys/user.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <cligen/cligen.h>
/* clicon */
#include "clixon_err.h"
#include "clixon_log.h"
#include "clixon_queue.h"
#include "clixon_hash.h"
#include "clixon_handle.h"
#include "clixon_sig.h"
#include "clixon_string.h"
#include "clixon_queue.h"
#include "clixon_proc.h"
/*
* Child process ID
* XXX Really shouldn't be a global variable
*/
static int _clicon_proc_child = 0;
/*
* Make sure child is killed by ctrl-C
*/
static void
clixon_proc_sigint(int sig)
{
if (_clicon_proc_child > 0)
kill(_clicon_proc_child, SIGINT);
}
/*! Fork a child process, setup a pipe between parent and child.
* Allowing parent to read the output of the child.
* @param[in] doerr If non-zero, stderr will be directed to the pipe as well.
* The pipe for the parent to write
* to the child is closed and cannot be used.
*
* When child process is done with the pipe setup, execute the specified
* command, execv(argv[0], argv).
*
* When parent is done with the pipe setup it will read output from the child
* until eof. The read output will be sent to the specified output callback,
* 'outcb' function.
*
* @param[in] argv NULL-terminated Argument vector
* @param[in] outcb
* @param[in] doerr
* @retval number Matches (processes affected).
* @retval -1 Error.
*/
int
clixon_proc_run(char **argv,
void (outcb)(char *),
int doerr)
{
int retval = -1;
char buf[512];
int outfd[2] = { -1, -1 };
int n;
int status;
pid_t child;
sigfn_t oldhandler = NULL;
sigset_t oset;
int sig = 0;
if (argv == NULL){
clicon_err(OE_UNIX, EINVAL, "argv is NULL");
goto done;
}
if (pipe(outfd) == -1){
clicon_err(OE_UNIX, errno, "pipe");
goto done;
}
sigprocmask(0, NULL, &oset);
set_signal(SIGINT, clixon_proc_sigint, &oldhandler);
sig++;
if ((child = fork()) < 0) {
clicon_err(OE_UNIX, errno, "fork");
goto done;
}
if (child == 0) { /* Child */
/* Unblock all signals except TSTP */
clicon_signal_unblock(0);
signal(SIGTSTP, SIG_IGN);
close(outfd[0]); /* Close unused read ends */
outfd[0] = -1;
/* Divert stdout and stderr to pipes */
dup2(outfd[1], STDOUT_FILENO);
if (doerr)
dup2(outfd[1], STDERR_FILENO);
execvp(argv[0], argv);
perror("execvp"); /* Shouldnt reach here */
exit(-1);
}
/* Parent */
/* Close unused write ends */
close(outfd[1]);
outfd[1] = -1;
/* Read from pipe */
while ((n = read(outfd[0], buf, sizeof(buf)-1)) != 0) {
if (n < 0) {
if (errno == EINTR)
continue;
break;
}
buf[n] = '\0';
/* Pass read data to callback function is defined */
if (outcb)
outcb(buf);
}
/* Wait for child to finish */
if(waitpid(child, &status, 0) == child)
retval = WEXITSTATUS(status);
done:
/* Clean up all pipes */
if (outfd[0] != -1)
close(outfd[0]);
if (outfd[1] != -1)
close(outfd[1]);
if (sig){ /* Restore sigmask and fn */
sigprocmask(SIG_SETMASK, &oset, NULL);
set_signal(SIGINT, oldhandler, NULL);
}
return retval;
}
/*! Fork and exec a sub-process, let it run and return pid
*
* @param[in] argv NULL-terminated Argument vector
* @param[in] netns Network namespace (or NULL)
* @param[out] pid
* @retval 0 OK
* @retval -1 Error.
* @see clixon_proc_daemon
* @note SIGCHLD is set to IGN here. Maybe it should be done in main?
*/
int
clixon_proc_background(char **argv,
char *netns,
pid_t *pid0)
{
int retval = -1;
pid_t child;
int i;
sigfn_t oldhandler = NULL;
sigset_t oset;
struct rlimit rlim = {0, };
clicon_debug(1, "%s netns:%s", __FUNCTION__, netns);
if (argv == NULL){
clicon_err(OE_UNIX, EINVAL, "argv is NULL");
goto quit;
}
/* Before here call quit on error */
sigprocmask(0, NULL, &oset);
set_signal(SIGINT, clixon_proc_sigint, &oldhandler);
/* Now call done on error */
if ((child = fork()) < 0) {
clicon_err(OE_UNIX, errno, "fork");
goto done;
}
if (child == 0) { /* Child */
char nsfile[PATH_MAX];
int nsfd;
clicon_debug(1, "%s child", __FUNCTION__);
clicon_signal_unblock(0);
signal(SIGTSTP, SIG_IGN);
if (chdir("/") < 0){
clicon_err(OE_UNIX, errno, "chdirq");
exit(1);
}
/* Close open descriptors */
if ( ! getrlimit(RLIMIT_NOFILE, &rlim))
for (i = 0; i < rlim.rlim_cur; i++)
close(i);
#ifdef HAVE_SETNS /* linux network namespaces */
/* If network namespace is defined, let child join it
* XXX: this is work-in-progress
*/
if (netns != NULL) {
snprintf(nsfile, PATH_MAX, "/var/run/netns/%s", netns); /* see man setns / ip netns */
clicon_debug(1, "%s nsfile:%s", __FUNCTION__, nsfile);
/* Change network namespace */
if ((nsfd = open(nsfile, O_RDONLY | O_CLOEXEC)) < 0){
clicon_err(OE_UNIX, errno, "open");
exit(1);
}
if (setns(nsfd, 0) < 0){ /* Join that namespace */
clicon_err(OE_UNIX, errno, "setns");
exit(1);
}
close(nsfd);
if (unshare(CLONE_NEWNS) < 0){
clicon_err(OE_UNIX, errno, "unshare");
exit(1);
}
}
#endif /* HAVE_SETNS */
clicon_debug(1, "%s argv0:%s", __FUNCTION__, argv[0]);
if (execv(argv[0], argv) < 0) {
clicon_err(OE_UNIX, errno, "execv");
exit(1);
}
/* Not reached */
}
done:
sigprocmask(SIG_SETMASK, &oset, NULL);
set_signal(SIGINT, oldhandler, NULL);
/* Ensure reap proc child in same session */
if (set_signal(SIGCHLD, SIG_IGN, NULL) < 0)
goto quit;
*pid0 = child;
retval = 0;
quit:
clicon_debug(1, "%s retval:%d child:%d", __FUNCTION__, retval, child);
return retval;
}
/*! Double fork and exec a sub-process as a daemon, let it run and return pid
*
* @param[in] argv NULL-terminated Argument vector
* @param[out] pid
* @retval 0 OK
* @retval -1 Error.
* @see clixon_proc_background
*/
int
clixon_proc_daemon(char **argv,
pid_t *pid0)
{
int retval = -1;
int status;
pid_t child;
pid_t pid;
int i;
struct rlimit rlim = {0, };
FILE *fpid = NULL;
if (argv == NULL){
clicon_err(OE_UNIX, EINVAL, "argv is NULL");
goto done;
}
if ((fpid = tmpfile()) == NULL){
clicon_err(OE_UNIX, errno, "tmpfile");
goto done;
}
if ((child = fork()) < 0) {
clicon_err(OE_UNIX, errno, "fork");
goto done;
}
if (child == 0) { /* Child */
clicon_signal_unblock(0);
if ((pid = fork()) < 0) {
clicon_err(OE_UNIX, errno, "fork");
return -1;
}
if (pid == 0) { /* Grandchild, create new session */
setsid();
if (chdir("/") < 0){
clicon_err(OE_UNIX, errno, "chdirq");
exit(1);
}
/* Close open descriptors */
if ( ! getrlimit(RLIMIT_NOFILE, &rlim))
for (i = 0; i < rlim.rlim_cur; i++)
close(i);
if (execv(argv[0], argv) < 0) {
clicon_err(OE_UNIX, errno, "execv");
exit(1);
}
/* Not reached */
}
if (fprintf(fpid, "%ld\n", (long) pid) < 1){
clicon_err(OE_DAEMON, errno, "fprintf Could not write pid");
goto done;
}
fclose(fpid);
// waitpid(pid, &status2, 0);
exit(pid);
}
if (waitpid(child, &status, 0) > 0){
pidfile_get_fd(fpid, pid0);
retval = 0;
}
fclose(fpid);
done:
clicon_debug(1, "%s retval:%d", __FUNCTION__, retval);
return retval;
}
/*--------------------------------------------------------------------------------*
* Process management: start/stop registered processes for internal use
*/
/*
* Types
*/
typedef struct {
qelem_t pe_qelem; /* List header */
char *pe_name; /* Name of process used for internal use */
char *pe_netns; /* Network namespace */
char **pe_argv; /* argv with command as element 0 and NULL-terminated */
pid_t pe_pid;
} process_entry_t;
/* List of process callback entries */
static process_entry_t *proc_entry_list = NULL;
/*! Register an internal process
*
* @param[in] h Clixon handle
* @param[in] name Process name
* @param[in] netns Namespace netspace (or NULL)
* @param[in] argv NULL-terminated vector of vectors
* @retval 0 OK
* @retval -1 Error
* @note name, netns, argv and its elements are all copied / re-alloced.
*/
int
clixon_process_register(clicon_handle h,
const char *name,
const char *netns,
char **argv,
int argc)
{
int retval = -1;
process_entry_t *pe = NULL;
int i;
if (name == NULL){
clicon_err(OE_DB, EINVAL, "name is NULL");
goto done;
}
if (argv == NULL){
clicon_err(OE_DB, EINVAL, "argv is NULL");
goto done;
}
if ((pe = malloc(sizeof(process_entry_t))) == NULL) {
clicon_err(OE_DB, errno, "malloc");
goto done;
}
memset(pe, 0, sizeof(*pe));
if ((pe->pe_name = strdup(name)) == NULL){
clicon_err(OE_DB, errno, "strdup name");
goto done;
}
if (netns && (pe->pe_netns = strdup(netns)) == NULL){
clicon_err(OE_DB, errno, "strdup netns");
goto done;
}
if ((pe->pe_argv = calloc(argc, sizeof(char *))) == NULL){
clicon_err(OE_UNIX, errno, "calloc");
goto done;
}
for (i=0; i<argc; i++){
if (argv[i] != NULL &&
(pe->pe_argv[i] = strdup(argv[i])) == NULL){
clicon_err(OE_UNIX, errno, "strdup");
}
}
ADDQ(pe, proc_entry_list);
retval = 0;
done:
return retval;
}
/*! Delete all Upgrade callbacks
*/
int
clixon_process_delete_all(clicon_handle h)
{
process_entry_t *pe;
char **pa;
while((pe = proc_entry_list) != NULL) {
DELQ(pe, proc_entry_list, process_entry_t *);
if (pe->pe_name)
free(pe->pe_name);
if (pe->pe_netns)
free(pe->pe_netns);
if (pe->pe_argv){
for (pa = pe->pe_argv; *pa != NULL; pa++){
if (*pa)
free(*pa);
}
free(pe->pe_argv);
}
free(pe);
}
return 0;
}
static int
proc_op_run(process_entry_t *pe,
int *runp)
{
int retval = -1;
int run;
pid_t pid;
run = 0;
if ((pid = pe->pe_pid) != 0){ /* if 0 stopped */
/* Check if lives */
run = 1;
if ((kill(pid, 0)) < 0){
if (errno == ESRCH){
run = 0;
}
else{
clicon_err(OE_UNIX, errno, "kill(%d)", pid);
goto done;
}
}
}
if (runp)
*runp = run;
retval = 0;
done:
return retval;
}
/*! Upgrade specific module identified by namespace, search matching callbacks
*
* @param[in] h clicon handle
* @param[in] name Name of process
* @param[in] op start, stop.
* @param[out] status true if process is running / false if not running on entry
* @retval -1 Error
* @retval 0 OK
* @see upgrade_callback_reg_fn which registers the callbacks
*/
int
clixon_process_operation(clicon_handle h,
char *name,
char *op,
int *status)
{
int retval = -1;
process_entry_t *pe;
int run;
clicon_debug(1, "%s name:%s op:%s", __FUNCTION__, name, op);
if (proc_entry_list == NULL)
goto ok;
pe = proc_entry_list;
do {
if (strcmp(pe->pe_name, name) == 0){
/* Check if running */
if (proc_op_run(pe, &run) < 0)
goto done;
if (status) /* Store as output parameter */
*status = run;
if (strcmp(op, "stop") == 0 ||
strcmp(op, "restart") == 0){
if (run)
pidfile_zapold(pe->pe_pid); /* Ensures its dead */
pe->pe_pid = 0; /* mark as dead */
run = 0;
}
if (strcmp(op, "start") == 0 ||
strcmp(op, "restart") == 0){
if (run == 1){
; /* Already runs */
}
else{
if (clixon_proc_background(pe->pe_argv, pe->pe_netns, &pe->pe_pid) < 0)
goto done;
}
}
else if (strcmp(op, "status") == 0){
; /* status already set */
}
break; /* hit break here */
}
pe = NEXTQ(process_entry_t *, pe);
} while (pe != proc_entry_list);
ok:
retval = 0;
done:
clicon_debug(1, "%s retval:%d", __FUNCTION__, retval);
return retval;
}

51
lib/src/clixon_sig.c
View file

@ -80,7 +80,6 @@ set_signal(int signo,
#endif
}
/*! Block signal.
* @param[in] sig Signal number to block, If 0, block all signals
*/
@ -117,34 +116,50 @@ clicon_signal_unblock (int sig)
sigprocmask (SIG_UNBLOCK, &set, NULL);
}
/*! Read pidfile and return pid using file descriptor
*
* @param[in] pidfile Name of pidfile
* @param[out] pid Process id of (eventual) existing daemon process
* @retval 0 OK. if pid > 0 old process exists w that pid
* @retval -1 Error, and clicon_err() called
*/
int
pidfile_get_fd(FILE *f,
pid_t *pid0)
{
char *ptr;
char buf[32];
pid_t pid;
*pid0 = 0;
ptr = fgets(buf, sizeof(buf), f);
if (ptr != NULL && (pid = atoi(ptr)) > 1) {
if (kill(pid, 0) == 0 || errno != ESRCH) {
/* Yes there is a process */
*pid0 = pid;
}
}
return 0;
}
/*! Read pidfile and return pid, if any
*
* @param[in] pidfile Name of pidfile
* @param[out] pid0 Process id of (eventual) existing daemon process
* @param[out] pid Process id of (eventual) existing daemon process
* @retval 0 OK. if pid > 0 old process exists w that pid
* @retval -1 Error, and clicon_err() called
*/
int
pidfile_get(char *pidfile,
pid_t *pid0)
pid_t *pid)
{
FILE *f;
char *ptr;
char buf[32];
pid_t pid;
if ((f = fopen (pidfile, "r")) != NULL){
ptr = fgets(buf, sizeof(buf), f);
fclose (f);
if (ptr != NULL && (pid = atoi (ptr)) > 1) {
if (kill (pid, 0) == 0 || errno != ESRCH) {
/* Yes there is a process */
*pid0 = pid;
return 0;
}
}
*pid = 0;
if ((f = fopen(pidfile, "r")) != NULL){
pidfile_get_fd(f, pid);
fclose(f);
}
*pid0 = 0;
return 0;
}
@ -169,7 +184,7 @@ pidfile_zapold(pid_t pid)
clicon_err(OE_UNIX, errno, "usleep");
goto done;
}
if ((kill (pid, 0)) < 0){
if ((kill(pid, 0)) < 0){
if (errno != ESRCH){
clicon_err(OE_DAEMON, errno, "Killing old demon");
goto done;