/*
** Copyright (C) 2001-2025 Zabbix SIA
**
** This program is free software: you can redistribute it and/or modify it under the terms of
** the GNU Affero General Public License as published by the Free Software Foundation, version 3.
**
** 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 Affero General Public License for more details.
**
** You should have received a copy of the GNU Affero General Public License along with this program.
** If not, see <https://www.gnu.org/licenses/>.
**/
/*
** Ideas from PostgreSQL implementation (src/backend/utils/misc/ps_status.c)
** were used in development of this file. Thanks to PostgreSQL developers!
**/
#include "zbxcommon.h"
#if defined(__linux__) /* Linux */
# define PS_OVERWRITE_ARGV
#elif defined(_AIX) /* AIX */
# define PS_OVERWRITE_ARGV
# define PS_CONCAT_ARGV
#elif defined(__sun) && defined(__SVR4) /* Solaris */
# define PS_OVERWRITE_ARGV
# define PS_APPEND_ARGV
#elif defined(HAVE_SYS_PSTAT_H) /* HP-UX */
# define PS_PSTAT_ARGV
#elif defined(__APPLE__) && defined(__MACH__) /* OS X */
# include <TargetConditionals.h>
# if TARGET_OS_MAC == 1 && TARGET_OS_EMBEDDED == 0 && TARGET_OS_IPHONE == 0 && TARGET_IPHONE_SIMULATOR == 0
# define PS_OVERWRITE_ARGV
# define PS_DARWIN_ARGV
# endif
#endif
#if defined(PS_DARWIN_ARGV)
#include <crt_externs.h>
#endif
#if defined(PS_OVERWRITE_ARGV)
/* external environment we got on startup */
extern char **environ;
static int argc_ext_copied_first = 0, argc_ext_copied_last = 0, environ_ext_copied = 0;
static char **environ_ext = NULL;
/* internal copy of argv[] and environment variables */
static char **argv_int = NULL, **environ_int = NULL;
static char *empty_str = "";
/* ps display buffer */
static char *ps_buf = NULL;
static size_t ps_buf_size = 0, prev_msg_size = 0;
#elif defined(PS_PSTAT_ARGV)
#define PS_BUF_SIZE 512
static char ps_buf[PS_BUF_SIZE], *p_msg = NULL;
static size_t ps_buf_size = PS_BUF_SIZE, ps_buf_size_msg = PS_BUF_SIZE;
#undef PS_BUF_SIZE
#endif
/******************************************************************************
* *
* Purpose: prepare for changing process commandline to display status *
* messages with "ps" command on platforms which do not support *
* setproctitle(). Depending on platform: *
* - make a copy of argc, argv[] and environment variables to *
* enable overwriting original argv[]. *
* - prepare a buffer with common part of status message. *
* *
* Comments: call this function soon after main process start, before using *
* argv[] and environment variables. *
* *
******************************************************************************/
#if defined(PS_OVERWRITE_ARGV)
char **zbx_setproctitle_init(int argc, char **argv)
{
int i;
char *arg_next = NULL;
if (NULL == argv || 0 == argc)
return argv;
/* measure a size of continuous argv[] area and make a copy */
argv_int = (char **)zbx_malloc(argv_int, ((unsigned int)argc + 1) * sizeof(char *));
#if defined(PS_APPEND_ARGV)
argc_ext_copied_first = argc - 1;
#else
argc_ext_copied_first = 0;
#endif
for (i = 0; i < argc_ext_copied_first; i++)
argv_int[i] = argv[i];
for (i = argc_ext_copied_first, arg_next = argv[argc_ext_copied_first]; arg_next == argv[i]; i++)
{
arg_next = argv[i] + strlen(argv[i]) + 1;
argv_int[i] = zbx_strdup(NULL, argv[i]);
/* argv[argc_ext_copied_first] will be used to display status messages. The rest of arguments can be */
/* overwritten and their argv[] pointers will point to wrong strings. */
if (argc_ext_copied_first < i)
argv[i] = empty_str;
}
argc_ext_copied_last = i - 1;
for (; i < argc; i++)
argv_int[i] = argv[i];
argv_int[argc] = NULL; /* C standard: "argv[argc] shall be a null pointer" */
if (argc_ext_copied_last == argc - 1)
{
int envc = 0;
while (NULL != environ[envc])
envc++;
/* measure a size of continuous environment area and make a copy */
environ_int = (char **)zbx_malloc(environ_int, ((unsigned int)envc + 1) * sizeof(char *));
for (i = 0; arg_next == environ[i]; i++)
{
arg_next = environ[i] + strlen(environ[i]) + 1;
environ_int[i] = zbx_strdup(NULL, environ[i]);
/* environment variables can be overwritten by status messages in argv[0] */
/* and environ[] pointers will point to wrong strings */
environ[i] = empty_str;
}
environ_ext_copied = i;
for (; i < envc; i++)
environ_int[i] = environ[i];
environ_int[envc] = NULL;
}
ps_buf_size = (size_t)(arg_next - argv[argc_ext_copied_first]);
ps_buf = argv[argc_ext_copied_first];
#if defined(PS_CONCAT_ARGV)
{
char *p = ps_buf;
size_t size = ps_buf_size, len;
for (i = argc_ext_copied_first + 1; i < argc; i++)
{
len = strlen(argv_int[i - 1]);
p += len;
size -= len;
if (2 >= size)
break;
zbx_strlcpy(p++, " ", size--);
zbx_strlcpy(p, argv_int[i], size);
}
}
#endif
#if defined(PS_DARWIN_ARGV)
*_NSGetArgv() = argv_int;
#endif
environ_ext = environ;
environ = environ_int; /* switch environment to internal copy */
return argv_int;
}
#elif defined(PS_PSTAT_ARGV)
char **zbx_setproctitle_init(int argc, char **argv)
{
size_t len0;
len0 = strlen(argv[0]);
if (len0 + 2 < ps_buf_size) /* is there space for ": " ? */
{
zbx_strlcpy(ps_buf, argv[0], ps_buf_size);
zbx_strlcpy(ps_buf + len0, ": ", (size_t)3);
p_msg = ps_buf + len0 + 2;
ps_buf_size_msg = ps_buf_size - len0 - 2; /* space after "argv[0]: " for status message */
}
return argv;
}
#else /* defined(PS_PSTAT_ARGV) */
char **zbx_setproctitle_init(int argc, char **argv)
{
return argv;
}
#endif
#if !defined(HAVE_FUNCTION_SETPROCTITLE) && (defined(PS_OVERWRITE_ARGV) || defined(PS_PSTAT_ARGV))
/******************************************************************************
* *
* Purpose: set a process command line displayed by "ps" command. *
* *
* Comments: call this function when a process starts some interesting task. *
* Program name argv[0] will be displayed "as-is" followed by ": " *
* and a status message. *
* *
******************************************************************************/
static void setproctitle_set_status(const char *status)
{
#if defined(PS_OVERWRITE_ARGV)
static int initialized = 0;
if (1 == initialized)
{
size_t msg_size;
msg_size = zbx_strlcpy(ps_buf, status, ps_buf_size);
if (prev_msg_size > msg_size)
memset(ps_buf + msg_size + 1, '\0', ps_buf_size - msg_size - 1);
prev_msg_size = msg_size;
}
else if (NULL != ps_buf)
{
size_t start_pos;
/* Initialization has not been moved to zbx_setproctitle_init() because zbx_setproctitle_init() */
/* is called from the main process and we do not change its command line. */
/* argv[] changing takes place only in child processes. */
#if defined(PS_CONCAT_ARGV)
start_pos = strlen(argv_int[0]);
#else
start_pos = strlen(ps_buf);
#endif
if (start_pos + 2 < ps_buf_size) /* is there space for ": " ? */
{
zbx_strlcpy(ps_buf + start_pos, ": ", (size_t)3);
ps_buf += start_pos + 2;
ps_buf_size -= start_pos + 2; /* space after "argv[copy_first]: " for status message */
memset(ps_buf, '\0', ps_buf_size);
prev_msg_size = zbx_strlcpy(ps_buf, status, ps_buf_size);
initialized = 1;
}
}
#elif defined(PS_PSTAT_ARGV)
if (NULL != p_msg)
{
union pstun pst;
zbx_strlcpy(p_msg, status, ps_buf_size_msg);
pst.pst_command = ps_buf;
pstat(PSTAT_SETCMD, pst, strlen(ps_buf), 0, 0);
}
#endif
}
#endif /* !defined(HAVE_FUNCTION_SETPROCTITLE) && (defined(PS_OVERWRITE_ARGV) || defined(PS_PSTAT_ARGV)) */
/******************************************************************************
* *
* Purpose: set process title *
* *
******************************************************************************/
void zbx_setproctitle(const char *fmt, ...)
{
#if defined(HAVE_FUNCTION_SETPROCTITLE) || defined(PS_OVERWRITE_ARGV) || defined(PS_PSTAT_ARGV)
char title[MAX_STRING_LEN];
va_list args;
va_start(args, fmt);
zbx_vsnprintf(title, sizeof(title), fmt, args);
va_end(args);
zabbix_log(LOG_LEVEL_DEBUG, "%s() title:'%s'", __func__, title);
#endif
#if defined(HAVE_FUNCTION_SETPROCTITLE)
setproctitle("%s", title);
#elif defined(PS_OVERWRITE_ARGV) || defined(PS_PSTAT_ARGV)
setproctitle_set_status(title);
#endif
}
/******************************************************************************
* *
* Purpose: release memory allocated in zbx_setproctitle_init(). *
* *
* Comments: call this function when process terminates and argv[] and *
* environment variables are not used anymore. *
* *
******************************************************************************/
void zbx_setproctitle_deinit(void)
{
#if defined(PS_OVERWRITE_ARGV)
int i;
/* restore the original environment variable to safely free our internally allocated environ array */
if (environ == environ_int)
environ = environ_ext;
for (i = argc_ext_copied_first; i <= argc_ext_copied_last; i++)
zbx_free(argv_int[i]);
for (i = 0; i <= environ_ext_copied; i++)
zbx_free(environ_int[i]);
zbx_free(argv_int);
zbx_free(environ_int);
#endif /* PS_OVERWRITE_ARGV */
}