/*
* msa_attach.c - Part of AFD, an automatic file distribution program.
* Copyright (c) 1998 - 2022 Holger Kiehl <Holger.Kiehl@dwd.de>
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "afddefs.h"
DESCR__S_M3
/*
** NAME
** msa_attach - attaches to the MSA
**
** SYNOPSIS
** int msa_attach(void)
** int msa_attach_passive(void)
**
** DESCRIPTION
** Attaches to the memory mapped area of the MSA (Monitor Status
** Area). The first 8 bytes of this area contains the number of
** AFD's that are being monitored. The rest consist of the
** structure mon_status_area for each AFD. When the function
** returns successful it returns the pointer 'msa' to the begining
** of the first structure.
**
** RETURN VALUES
** SUCCESS when attaching to the MSA successful and sets the
** global pointer 'msa' to the start of the MSA and the size of
** the memory mapped file is returned. Also the MSA ID and the
** number of AFD's in the MSA is returned in 'msa_id' and
** 'no_of_afds' respectively. Otherwise INCORRECT is returned.
**
** AUTHOR
** H.Kiehl
**
** HISTORY
** 30.08.1998 H.Kiehl Created
** 12.03.2009 H.Kiehl Added function msa_attach_passive().
**
*/
DESCR__E_M3
#include <stdio.h>
#include <string.h> /* strerror(), strlen() */
#include <unistd.h> /* close(), read() */
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_MMAP
# include <sys/mman.h> /* mmap(), munmap() */
#endif
#ifdef HAVE_FCNTL_H
# include <fcntl.h> /* fcntl() */
#endif
#include <errno.h>
#include "mondefs.h"
/* Global variables. */
extern int msa_fd,
msa_id,
no_of_afds;
#ifdef HAVE_MMAP
extern off_t msa_size;
#endif
extern char *p_work_dir;
extern struct mon_status_area *msa;
/*############################ msa_attach() #############################*/
int
msa_attach(void)
{
int fd,
loop_counter,
retries = 0,
timeout_loops = 0;
char *ptr = NULL,
*p_msa_stat_file,
msa_id_file[MAX_PATH_LENGTH],
msa_stat_file[MAX_PATH_LENGTH];
struct flock wlock = {F_WRLCK, SEEK_SET, 0, 1},
ulock = {F_UNLCK, SEEK_SET, 0, 1};
#ifdef HAVE_STATX
struct statx stat_buf;
#else
struct stat stat_buf;
#endif
/* Get absolute path of MSA_ID_FILE. */
(void)strcpy(msa_id_file, p_work_dir);
(void)strcat(msa_id_file, FIFO_DIR);
(void)strcpy(msa_stat_file, msa_id_file);
(void)strcat(msa_stat_file, MON_STATUS_FILE);
p_msa_stat_file = msa_stat_file + strlen(msa_stat_file);
(void)strcat(msa_id_file, MSA_ID_FILE);
do
{
/* Make sure this is not the case when the */
/* no_of_afds is stale. */
if ((no_of_afds < 0) && (msa != NULL))
{
/* Unmap from MSA. */
ptr = (char *)msa - AFD_WORD_OFFSET;
#ifdef HAVE_MMAP
if (munmap((void *)ptr, msa_size) == -1)
#else
if (munmap_emu((void *)ptr) == -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to munmap() `%s' : %s"),
msa_stat_file, strerror(errno));
}
else
{
msa = NULL;
}
timeout_loops++;
if (timeout_loops > 200)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Unable to attach to a new MSA."));
return(INCORRECT);
}
/* No need to speed things up here. */
my_usleep(400000L);
}
/*
* Retrieve the MSA (Monitor Status Area) ID from MSA_ID_FILE.
* Make sure that it is not locked.
*/
loop_counter = 0;
while ((fd = coe_open(msa_id_file, O_RDWR)) == -1)
{
if (errno == ENOENT)
{
my_usleep(400000L);
if (loop_counter++ > 24)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to coe_open() `%s' : %s"),
msa_id_file, strerror(errno));
return(INCORRECT);
}
}
else
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to coe_open() `%s' : %s"),
msa_id_file, strerror(errno));
return(INCORRECT);
}
}
/* Check if its locked. */
if (fcntl(fd, F_SETLKW, &wlock) == -1)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Could not set write lock for `%s' : %s"),
msa_id_file, strerror(errno));
(void)close(fd);
return(INCORRECT);
}
/* Read the msa_id. */
if (read(fd, &msa_id, sizeof(int)) < 0)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Could not read the value of the msa_id : %s"),
strerror(errno));
(void)close(fd);
return(INCORRECT);
}
/* Unlock file and close it. */
if (fcntl(fd, F_SETLKW, &ulock) == -1)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Could not unlock `%s' : %s"),
msa_id_file, strerror(errno));
(void)close(fd);
return(INCORRECT);
}
if (close(fd) == -1)
{
system_log(WARN_SIGN, __FILE__, __LINE__,
_("Could not close() `%s' : %s"),
msa_id_file, strerror(errno));
}
(void)snprintf(p_msa_stat_file,
MAX_PATH_LENGTH - (p_msa_stat_file - msa_stat_file),
".%d", msa_id);
if (msa_fd > 0)
{
if (close(msa_fd) == -1)
{
system_log(DEBUG_SIGN, __FILE__, __LINE__,
_("close() error : %s"), strerror(errno));
}
}
if ((msa_fd = coe_open(msa_stat_file, O_RDWR)) == -1)
{
if (errno == ENOENT)
{
if (retries++ > 8)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_stat_file, strerror(errno));
return(INCORRECT);
}
else
{
system_log(WARN_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_stat_file, strerror(errno));
(void)sleep(1);
continue;
}
}
else
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_stat_file, strerror(errno));
return(INCORRECT);
}
}
#ifdef HAVE_STATX
if (statx(msa_fd, "", AT_STATX_SYNC_AS_STAT | AT_EMPTY_PATH,
STATX_SIZE, &stat_buf) == -1)
#else
if (fstat(msa_fd, &stat_buf) == -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
#ifdef HAVE_STATX
_("Failed to statx() `%s' : %s"),
#else
_("Failed to fstat() `%s' : %s"),
#endif
msa_stat_file, strerror(errno));
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT);
}
#ifdef HAVE_MMAP
if ((ptr = mmap(NULL,
# ifdef HAVE_STATX
stat_buf.stx_size, (PROT_READ | PROT_WRITE),
# else
stat_buf.st_size, (PROT_READ | PROT_WRITE),
# endif
MAP_SHARED, msa_fd, 0)) == (caddr_t) -1)
#else
if ((ptr = mmap_emu(NULL,
# ifdef HAVE_STATX
stat_buf.stx_size, (PROT_READ | PROT_WRITE),
# else
stat_buf.st_size, (PROT_READ | PROT_WRITE),
# endif
MAP_SHARED, msa_stat_file, 0)) == (caddr_t) -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("mmap() error : %s"), strerror(errno));
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT);
}
/* Read number of AFD's. */
no_of_afds = *(int *)ptr;
/* Check MSA version number. */
if ((no_of_afds > 0) &&
(*(ptr + SIZEOF_INT + 1 + 1 + 1) != CURRENT_MSA_VERSION))
{
system_log(WARN_SIGN, __FILE__, __LINE__,
_("This code is compiled for of MSA version %d, but the MSA we try to attach is %d."),
CURRENT_MSA_VERSION, (int)(*(ptr + SIZEOF_INT + 1 + 1 + 1)));
#ifdef HAVE_MMAP
# ifdef HAVE_STATX
if (munmap(ptr, stat_buf.stx_size) == -1)
# else
if (munmap(ptr, stat_buf.st_size) == -1)
# endif
#else
if (munmap_emu(ptr) == -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to munmap() MSA : %s"), strerror(errno));
}
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT_VERSION);
}
ptr += AFD_WORD_OFFSET;
msa = (struct mon_status_area *)ptr;
#ifdef HAVE_MMAP
# ifdef HAVE_STATX
msa_size = stat_buf.stx_size;
# else
msa_size = stat_buf.st_size;
# endif
#endif
} while (no_of_afds <= 0);
return(SUCCESS);
}
/*######################## msa_attach_passive() #########################*/
int
msa_attach_passive(void)
{
int fd,
retries = 0,
timeout_loops = 0;
char *ptr = NULL,
*p_msa_stat_file,
msa_id_file[MAX_PATH_LENGTH],
msa_stat_file[MAX_PATH_LENGTH];
struct flock rlock = {F_RDLCK, SEEK_SET, 0, 1};
#ifdef HAVE_STATX
struct statx stat_buf;
#else
struct stat stat_buf;
#endif
/* Get absolute path of MSA_ID_FILE. */
(void)strcpy(msa_id_file, p_work_dir);
(void)strcat(msa_id_file, FIFO_DIR);
(void)strcpy(msa_stat_file, msa_id_file);
(void)strcat(msa_stat_file, MON_STATUS_FILE);
p_msa_stat_file = msa_stat_file + strlen(msa_stat_file);
(void)strcat(msa_id_file, MSA_ID_FILE);
do
{
/* Make sure this is not the case when the */
/* no_of_afds is stale. */
if ((no_of_afds < 0) && (msa != NULL))
{
/* Unmap from MSA. */
ptr = (char *)msa - AFD_WORD_OFFSET;
#ifdef HAVE_MMAP
if (munmap(ptr, msa_size) == -1)
#else
if (munmap_emu((void *)ptr) == -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to munmap() `%s' : %s"),
msa_stat_file, strerror(errno));
}
else
{
msa = NULL;
}
timeout_loops++;
if (timeout_loops > 200)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Unable to attach to a new MSA."));
return(INCORRECT);
}
/* No need to speed things up here. */
my_usleep(400000L);
}
/* Read the MSA ID. */
if ((fd = coe_open(msa_id_file, O_RDONLY)) == -1)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_id_file, strerror(errno));
return(INCORRECT);
}
if (fcntl(fd, F_SETLKW, &rlock) == -1)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Could not get read lock for `%s' : %s"),
msa_id_file, strerror(errno));
(void)close(fd);
return(INCORRECT);
}
if (read(fd, &msa_id, sizeof(int)) < 0)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Could not read the value of the msa_id : %s"),
strerror(errno));
(void)close(fd);
return(INCORRECT);
}
if (close(fd) == -1)
{
system_log(WARN_SIGN, __FILE__, __LINE__,
_("Could not close() `%s' : %s"),
msa_id_file, strerror(errno));
}
(void)snprintf(p_msa_stat_file,
MAX_PATH_LENGTH - (p_msa_stat_file - msa_stat_file),
".%d", msa_id);
if (msa_fd > 0)
{
if (close(msa_fd) == -1)
{
system_log(DEBUG_SIGN, __FILE__, __LINE__,
_("close() error : %s"), strerror(errno));
}
}
if ((msa_fd = coe_open(msa_stat_file, O_RDONLY)) == -1)
{
if (errno == ENOENT)
{
if (retries++ > 8)
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_stat_file, strerror(errno));
return(INCORRECT);
}
else
{
system_log(WARN_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_stat_file, strerror(errno));
(void)sleep(1);
continue;
}
}
else
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to open() `%s' : %s"),
msa_stat_file, strerror(errno));
return(INCORRECT);
}
}
#ifdef HAVE_STATX
if (statx(msa_fd, "", AT_STATX_SYNC_AS_STAT | AT_EMPTY_PATH,
STATX_SIZE, &stat_buf) == -1)
#else
if (fstat(msa_fd, &stat_buf) == -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
#ifdef HAVE_STATX
_("Failed to statx() `%s' : %s"),
#else
_("Failed to fstat() `%s' : %s"),
#endif
msa_stat_file, strerror(errno));
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT);
}
#ifdef HAVE_STATX
if (stat_buf.stx_size < AFD_WORD_OFFSET)
#else
if (stat_buf.st_size < AFD_WORD_OFFSET)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("MSA not large enough to contain any meaningful data."));
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT);
}
#ifdef HAVE_MMAP
if ((ptr = mmap(NULL,
# ifdef HAVE_STATX
stat_buf.stx_size, PROT_READ,
# else
stat_buf.st_size, PROT_READ,
# endif
MAP_SHARED, msa_fd, 0)) == (caddr_t) -1)
#else
if ((ptr = mmap_emu(NULL,
# ifdef HAVE_STATX
stat_buf.stx_size, PROT_READ,
# else
stat_buf.st_size, PROT_READ,
# endif
MAP_SHARED, msa_stat_file, 0)) == (caddr_t) -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("mmap() error : %s"), strerror(errno));
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT);
}
/* Read number of current MSA. */
no_of_afds = *(int *)ptr;
/* Check MSA version number. */
if ((no_of_afds > 0) &&
(*(ptr + SIZEOF_INT + 1 + 1 + 1) != CURRENT_MSA_VERSION))
{
system_log(WARN_SIGN, __FILE__, __LINE__,
"This code is compiled for of MSA version %d, but the MSA we try to attach is %d.",
CURRENT_MSA_VERSION, (int)(*(ptr + SIZEOF_INT + 1 + 1 + 1)));
#ifdef HAVE_MMAP
# ifdef HAVE_STATX
if (munmap(ptr, stat_buf.stx_size) == -1)
# else
if (munmap(ptr, stat_buf.st_size) == -1)
# endif
#else
if (munmap_emu(ptr) == -1)
#endif
{
system_log(ERROR_SIGN, __FILE__, __LINE__,
_("Failed to munmap() MSA : %s"), strerror(errno));
}
(void)close(msa_fd);
msa_fd = -1;
return(INCORRECT_VERSION);
}
ptr += AFD_WORD_OFFSET;
msa = (struct mon_status_area *)ptr;
#ifdef HAVE_MMAP
# ifdef HAVE_STATX
msa_size = stat_buf.stx_size;
# else
msa_size = stat_buf.st_size;
# endif
#endif
} while (no_of_afds <= 0);
return(SUCCESS);
}