mi_fifo.c

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/*
 * $Id$
 *
 * Copyright (C) 2006 Voice Sistem SRL
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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.
 *
 * Kamailio 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *
 * History:
 * ---------
 *  2006-09-25  first version (bogdan)
 */

#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>

#include "../../sr_module.h"
#include "../../dprint.h"
#include "../../ut.h"
#include "../../pt.h"
#include "../../globals.h"
#include "../../mem/mem.h"
#include "../../mem/shm_mem.h"
#include "../../cfg/cfg_struct.h"
#include "../../lib/kmi/mi.h"
#include "mi_fifo.h"
#include "mi_parser.h"
#include "mi_writer.h"
#include "fifo_fnc.h"

static int mi_mod_init(void);
static int mi_child_init(int rank);
static void fifo_process(int rank);
static int mi_destroy(void);

/* FIFO server vars */
static char *mi_fifo = 0;                               
static char *mi_fifo_reply_dir = DEFAULT_MI_REPLY_DIR;  
static char *mi_reply_indent = DEFAULT_MI_REPLY_IDENT;
static int  mi_fifo_uid = -1;                           
static char *mi_fifo_uid_s = 0;                         
static int  mi_fifo_gid = -1;                           
static char *mi_fifo_gid_s = 0;                         
static int  mi_fifo_mode = S_IRUSR| S_IWUSR| S_IRGRP| S_IWGRP; /* Default file mode rw-rw---- */
static int  read_buf_size = MAX_MI_FIFO_READ;

MODULE_VERSION

static param_export_t mi_params[] = {                   
        {"fifo_name",        STR_PARAM, &mi_fifo},
        {"fifo_mode",        INT_PARAM, &mi_fifo_mode},
        {"fifo_group",       STR_PARAM, &mi_fifo_gid_s},
        {"fifo_group",       INT_PARAM, &mi_fifo_gid},
        {"fifo_user",        STR_PARAM, &mi_fifo_uid_s},
        {"fifo_user",        INT_PARAM, &mi_fifo_uid},
        {"reply_dir",        STR_PARAM, &mi_fifo_reply_dir},
        {"reply_indent",     STR_PARAM, &mi_reply_indent},
        {0,0,0}
};


static proc_export_t mi_procs[] = {
        {"MI FIFO",  0,  0,  fifo_process,  1 },
        {0,0,0,0,0}
};


struct module_exports exports = {
        "mi_fifo",                     
        DEFAULT_DLFLAGS,               
        0,                             
        mi_params,                     
        0,                             
        0,                             
        0,                             
        mi_procs,                      
        mi_mod_init,                   
        0,                             
        (destroy_function) mi_destroy, 
        mi_child_init                  
};



static int mi_mod_init(void)
{
        int n;
        struct stat filestat;

        /* checking the mi_fifo module param */
        if (mi_fifo==NULL || *mi_fifo == 0) {
                LM_ERR("No MI fifo configured\n");
                return -1;
        }

        LM_DBG("testing mi_fifo existance ...\n");
        n=stat(mi_fifo, &filestat);
        if (n==0) {
                /* FIFO exist, delete it (safer) if no config check */
                if(config_check==0) {
                        if (unlink(mi_fifo)<0){
                                LM_ERR("Cannot delete old MI fifo (%s): %s\n",
                                        mi_fifo, strerror(errno));
                                return -1;
                        }
                }
        } else if (n<0 && errno!=ENOENT){
                LM_ERR("MI FIFO stat failed: %s\n", strerror(errno));
                return -1;
        }

        /* checking the mi_fifo_reply_dir param */
        if(!mi_fifo_reply_dir || *mi_fifo_reply_dir == 0) {
                LM_ERR("mi_fifo_reply_dir parameter is empty\n");
                return -1;
        }

        /* Check if the directory for the reply fifo exists */
        n = stat(mi_fifo_reply_dir, &filestat);
        if(n < 0){
                LM_ERR("Directory stat for MI Fifo reply failed: %s\n", strerror(errno));
                return -1;
        }

        if(S_ISDIR(filestat.st_mode) == 0){
                LM_ERR("mi_fifo_reply_dir parameter is not a directory\n");
                return -1;
        }

        /* check mi_fifo_mode */
        if(!mi_fifo_mode){
                LM_WARN("cannot specify mi_fifo_mode = 0, forcing it to rw-------\n");
                mi_fifo_mode = S_IRUSR| S_IWUSR;
        }

        if (mi_fifo_uid_s){
                if (user2uid(&mi_fifo_uid, &mi_fifo_gid, mi_fifo_uid_s)<0){
                        LM_ERR("Bad user name %s\n", mi_fifo_uid_s);
                        return -1;
                }
        }

        if (mi_fifo_gid_s){
                if (group2gid(&mi_fifo_gid, mi_fifo_gid_s)<0){
                        LM_ERR("Bad group name %s\n", mi_fifo_gid_s);
                        return -1;
                }
        }

        /* add space for one extra process */
        register_procs(1);

        /* add child to update local config framework structures */
        cfg_register_child(1);

        return 0;
}


static int mi_child_init(int rank)
{
        int pid;

        if (rank==PROC_TIMER || rank>0 ) {
                if ( mi_writer_init(read_buf_size, mi_reply_indent)!=0 ) {
                        LM_CRIT("failed to init the reply writer\n");
                        return -1;
                }
        }

        if (rank==PROC_MAIN) {
                pid=fork_process(PROC_NOCHLDINIT, "MI FIFO", 1);
                if (pid<0)
                        return -1; /* error */
                if(pid==0){
                        /* child */

                        /* initialize the config framework */
                        if (cfg_child_init())
                                return -1;

                        fifo_process(1);
                }
        }

        return 0;
}


static void fifo_process(int rank)
{
        FILE *fifo_stream;

        LM_DBG("new process with pid = %d created\n",getpid());

        fifo_stream = mi_init_fifo_server( mi_fifo, mi_fifo_mode,
                mi_fifo_uid, mi_fifo_gid, mi_fifo_reply_dir);
        if ( fifo_stream==NULL ) {
                LM_CRIT("The function mi_init_fifo_server returned with error!!!\n");
                exit(-1);
        }

        if( init_mi_child(PROC_NOCHLDINIT, 1)!=0) {
                LM_CRIT("Failed to init the mi process\n");
                exit(-1);
        }

        if ( mi_parser_init(read_buf_size)!=0 ) {
                LM_CRIT("Failed to init the command parser\n");
                exit(-1);
        }

        if ( mi_writer_init(read_buf_size, mi_reply_indent)!=0 ) {
                LM_CRIT("Failed to init the reply writer\n");
                exit(-1);
        }

        mi_fifo_server( fifo_stream );

        LM_CRIT("the function mi_fifo_server returned with error!!!\n");
        exit(-1);
}


static int mi_destroy(void)
{
        int n;
        struct stat filestat;

        /* destroying the fifo file */
        n=stat(mi_fifo, &filestat);
        if (n==0){
                /* FIFO exist, delete it (safer) if not config check */
                if(config_check==0) {
                        if (unlink(mi_fifo)<0){
                                LM_ERR("cannot delete the fifo (%s): %s\n",
                                        mi_fifo, strerror(errno));
                                goto error;
                        }
                }
        } else if (n<0 && errno!=ENOENT) {
                LM_ERR("FIFO stat failed: %s\n", strerror(errno));
                goto error;
        }

        return 0;
error:
        return -1;
}