/*
  * $Id$
  *
  * Process Table
  *
  *
  *
  * Copyright (C) 2001-2003 FhG Fokus
  *
  * This file is part of ser, a free SIP server.
  *
  * ser 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
  *
  * For a license to use the ser software under conditions
  * other than those described here, or to purchase support for this
  * software, please contact iptel.org by e-mail at the following addresses:
  *    info@iptel.org
  *
  * ser 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:
  * --------
  *  2006-06-14	added process table in shared mem (dragos)

  *  2006-09-20	added profile support (-DPROFILING) (hscholz)

  *  2006-10-25	sanity check before allowing forking w/ tcp support (is_main
  *               & tcp not started yet); set is_main=0 in childs (andrei)

  *  2007-07-04	added register_fds() and get_max_open_fds(() (andrei)

  */
 
 
 #include "pt.h"
 #include "tcp_init.h"
 #include "sr_module.h"

 #include "socket_info.h"

 #include "rand/fastrand.h"

 #ifdef PKG_MALLOC
 #include "mem/mem.h"
 #endif
 #ifdef SHM_MEM
 #include "mem/shm_mem.h"
 #endif
 #if defined PKG_MALLOC || defined SHM_MEM
 #include "cfg_core.h"
 #endif

 #include <stdio.h>

 #include <time.h> /* time(), used to initialize random numbers */

 
 #define FORK_DONT_WAIT  /* child doesn't wait for parent before starting 
 						   => faster startup, but the child should not assume
 						   the parent fixed the pt[] entry for it */
 
 

 #ifdef PROFILING
 #include <sys/gmon.h>
 
 	extern void _start(void);
 	extern void etext(void);
 #endif

 
 
 static int estimated_proc_no=0;

 static int estimated_fds_no=0;
 
 
 /* number of known "common" used fds */
 static int calc_common_open_fds_no()
 {
 	int max_fds_no;
 	
 	/* 1 tcp send unix socket/all_proc, 
 	 *  + 1 udp sock/udp proc + 1 possible dns comm. socket + 
 	 *  + 1 temporary tcp send sock.
 	 */

 	max_fds_no=estimated_proc_no*4 /* udp|sctp + tcp unix sock +
 									  tmp. tcp send +
 									  tmp dns.*/
 				-1 /* timer (no udp)*/ + 3 /* stdin/out/err */;

 	return max_fds_no;
 }
 
 

 
 /* returns 0 on success, -1 on error */
 int init_pt(int proc_no)
 {

 #ifdef USE_TCP
 	int r;
 #endif
 	

 	estimated_proc_no+=proc_no;

 	estimated_fds_no+=calc_common_open_fds_no();

 	/*alloc pids*/
 #ifdef SHM_MEM
 	pt=shm_malloc(sizeof(struct process_table)*estimated_proc_no);
 	process_count = shm_malloc(sizeof(int));
 #else
 	pt=pkg_malloc(sizeof(struct process_table)*estimated_proc_no);
 	process_count = pkg_malloc(sizeof(int));
 #endif
 	process_lock = lock_alloc();
 	process_lock = lock_init(process_lock);
 	if (pt==0||process_count==0||process_lock==0){
 		LOG(L_ERR, "ERROR: out  of memory\n");
 		return -1;
 	}
 	memset(pt, 0, sizeof(struct process_table)*estimated_proc_no);

 #ifdef USE_TCP
 	for (r=0; r<estimated_proc_no; r++){
 		pt[r].unix_sock=-1;
 		pt[r].idx=-1;
 	}
 #endif

 	process_no=0; /*main process number*/
 	pt[process_no].pid=getpid();

 	memcpy(pt[process_no].desc,"main",5);

 	*process_count=1;
 	return 0;
 }
 
 
 /* register no processes, used from mod_init when processes will be forked
  *  from mod_child 
  *  returns 0 on success, -1 on error
  */
 int register_procs(int no)
 {
 	if (pt){
 		LOG(L_CRIT, "BUG: register_procs(%d) called at runtime\n", no);
 		return -1;
 	}
 	estimated_proc_no+=no;
 	return 0;
 }
 
 
 
 /* returns the maximum number of processes */
 int get_max_procs()
 {

 	if (pt==0){
 		LOG(L_CRIT, "BUG: get_max_procs() called too early "
 				"(it must _not_ be called from mod_init())\n");
 		abort(); /* crash to quickly catch offenders */
 	}

 	return estimated_proc_no;
 }
 
 

 /* register no fds, used from mod_init when modules will open more global
  *  fds (from mod_init or child_init(PROC_INIT)
  *  or from child_init(rank) when the module will open fds local to the
  *   process "rank".
  *   (this is needed because some other parts of ser code rely on knowing
  *    the maximum open fd number in a process)
  *  returns 0 on success, -1 on error
  */
 int register_fds(int no)
 {
 	/* can be called at runtime, but should be called from child_init() */
 	estimated_fds_no+=no;
 	return 0;
 }
 
 
 
 /* returns the maximum open fd number */
 int get_max_open_fds()
 {
 	if (pt==0){
 		LOG(L_CRIT, "BUG: get_max_open_fds() called too early "
 				"(it must _not_ be called from mod_init())\n");
 		abort(); /* crash to quickly catch offenders */
 	}
 	return estimated_fds_no;
 }
 
 

 /* return processes pid */

 int my_pid()

 {
 	return pt ? pt[process_no].pid : getpid();
 }
 

 /* close unneeded sockets */
 int close_extra_socks(int child_id, int proc_no)
 {
 #ifdef USE_TCP
 	int r;
 	struct socket_info* si;
 	
 	if (child_id!=PROC_TCP_MAIN){
 		for (r=0; r<proc_no; r++){
 			if (pt[r].unix_sock>=0){
 				/* we can't change the value in pt[] because it's
 				 * shared so we only close it */
 				close(pt[r].unix_sock);
 			}
 		}
 		/* close all listen sockets (needed only in tcp_main */
 		if (!tcp_disable){
 			for(si=tcp_listen; si; si=si->next){
 				close(si->socket);
 				/* safe to change since this is a per process copy */
 				si->socket=-1;
 			}
 #ifdef USE_TLS
 			if (!tls_disable){
 				for(si=tls_listen; si; si=si->next){
 					close(si->socket);
 					/* safe to change since this is a per process copy */
 					si->socket=-1;
 				}
 			}
 #endif /* USE_TLS */
 		}
 		/* we still need the udp sockets (for sending) so we don't close them
 		 * too */
 	}
 #endif /* USE_TCP */
 	return 0;
 }
 
 
 

 /**
  * Forks a new process.
  * @param child_id - rank, if equal to PROC_NOCHLDINIT init_child will not be
  *                   called for the new forked process (see sr_module.h)
  * @param desc - text description for the process table
  * @param make_sock - if to create a unix socket pair for it
  * @returns the pid of the new process
  */

 int fork_process(int child_id, char *desc, int make_sock)

 {

 	int pid, child_process_no;
 	int ret;

 	unsigned int new_seed1;
 	unsigned int new_seed2;

 #ifdef USE_TCP
 	int sockfd[2];
 #endif
 

 	ret=-1;

 	#ifdef USE_TCP

 		sockfd[0]=sockfd[1]=-1;

 		if(make_sock && !tcp_disable){

 			 if (!is_main){
 				 LOG(L_CRIT, "BUG: fork_process(..., 1) called from a non "
 						 "\"main\" process! If forking from a module's "
 						 "child_init() fork only if rank==PROC_MAIN or"
 						 " give up tcp send support (use 0 for make_sock)\n");
 				 goto error;
 			 }
 			 if (tcp_main_pid){
 				 LOG(L_CRIT, "BUG: fork_process(..., 1) called, but tcp main "
 						 " is already started\n");
 				 goto error;
 			 }

 			 if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockfd)<0){
 				LOG(L_ERR, "ERROR: fork_process(): socketpair failed: %s\n",

 							strerror(errno));
 				goto error;

 			}
 		}
 	#endif

 	lock_get(process_lock);
 	if (*process_count>=estimated_proc_no) {
 		LOG(L_CRIT, "ERROR: fork_process(): Process limit of %d exceeded."
 					" Will simulate fork fail.\n", estimated_proc_no);
 		lock_release(process_lock);
 		goto error;
 	}	

 	
 	child_process_no = *process_count;

 	new_seed1=rand();
 	new_seed2=random();

 	pid = fork();
 	if (pid<0) {
 		lock_release(process_lock);

 		ret=pid;
 		goto error;
 	}else if (pid==0){

 		/* child */

 		is_main=0; /* a forked process cannot be the "main" one */

 		process_no=child_process_no;

 		/* close tcp unix sockets if this is not tcp main */
 #ifdef USE_TCP
 		close_extra_socks(child_id, process_no);
 #endif /* USE_TCP */

 		srand(new_seed1);

 		fastrand_seed(rand());

 		srandom(new_seed2+time(0));

 		shm_malloc_on_fork();

 #ifdef PROFILING
 		monstartup((u_long) &_start, (u_long) &etext);
 #endif

 #ifdef FORK_DONT_WAIT
 		/* record pid twice to avoid the child using it, before
 		 * parent gets a chance to set it*/
 		pt[process_no].pid=getpid();
 #else

 		/* wait for parent to get out of critical zone.
 		 * this is actually relevant as the parent updates
 		 * the pt & process_count. */
 		lock_get(process_lock);

 		lock_release(process_lock);

 #endif

 		#ifdef USE_TCP
 			if (make_sock && !tcp_disable){
 				close(sockfd[0]);
 				unix_tcp_sock=sockfd[1];
 			}
 		#endif		
 		if ((child_id!=PROC_NOCHLDINIT) && (init_child(child_id) < 0)) {

 			LOG(L_ERR, "ERROR: fork_process(): init_child failed for "
 					" process %d, pid %d, \"%s\"\n", process_no,
 					pt[process_no].pid, pt[process_no].desc);

 			return -1;
 		}
 		return pid;
 	} else {
 		/* parent */

 		(*process_count)++;
 #ifdef FORK_DONT_WAIT
 		lock_release(process_lock);
 #endif

 		/* add the process to the list in shm */

 		pt[child_process_no].pid=pid;

 		if (desc){

 			strncpy(pt[child_process_no].desc, desc, MAX_PT_DESC);

 		}
 		#ifdef USE_TCP
 			if (make_sock && !tcp_disable){
 				close(sockfd[1]);

 				pt[child_process_no].unix_sock=sockfd[0];

 				pt[child_process_no].idx=-1; /* this is not a "tcp" process*/

 			}

 		#endif
 #ifdef FORK_DONT_WAIT
 #else

 		lock_release(process_lock);

 #endif
 		ret=pid;
 		goto end;

 	}

 error:
 #ifdef USE_TCP
 	if (sockfd[0]!=-1) close(sockfd[0]);
 	if (sockfd[1]!=-1) close(sockfd[1]);
 #endif
 end:
 	return ret;

 }
 
 /**
  * Forks a new TCP process.
  * @param desc - text description for the process table
  * @param r - index in the tcp_children array
  * @param *reader_fd_1 - pointer to return the reader_fd[1]
  * @returns the pid of the new process
  */

 #ifdef USE_TCP

 int fork_tcp_process(int child_id, char *desc, int r, int *reader_fd_1)

 {

 	int pid, child_process_no;

 	int sockfd[2];
 	int reader_fd[2]; /* for comm. with the tcp children read  */

 	int ret;

 	int i;

 	unsigned int new_seed1;
 	unsigned int new_seed2;

 	/* init */
 	sockfd[0]=sockfd[1]=-1;
 	reader_fd[0]=reader_fd[1]=-1;
 	ret=-1;

 	if (!is_main){
 		 LOG(L_CRIT, "BUG: fork_tcp_process() called from a non \"main\" "
 				 	"process\n");
 		 goto error;
 	 }
 	 if (tcp_main_pid){
 		 LOG(L_CRIT, "BUG: fork_tcp_process(..., 1) called _after_ starting"
 				 	" tcp main\n");
 		 goto error;
 	 }

 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockfd)<0){
 		LOG(L_ERR, "ERROR: fork_tcp_process(): socketpair failed: %s\n",
 					strerror(errno));

 		goto error;

 	}
 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, reader_fd)<0){
 		LOG(L_ERR, "ERROR: fork_tcp_process(): socketpair failed: %s\n",
 					strerror(errno));

 		goto error;

 	}
 	if (tcp_fix_child_sockets(reader_fd)<0){
 		LOG(L_ERR, "ERROR: fork_tcp_process(): failed to set non blocking"
 					"on child sockets\n");
 		/* continue, it's not critical (it will go slower under
 		 * very high connection rates) */
 	}

 	lock_get(process_lock);
 	/* set the local process_no */
 	if (*process_count>=estimated_proc_no) {
 		LOG(L_CRIT, "ERROR: fork_tcp_process(): Process limit of %d exceeded."
 					" Simulating fork fail\n", estimated_proc_no);
 		lock_release(process_lock);
 		goto error;
 	}
 	

 	child_process_no = *process_count;

 	new_seed1=rand();
 	new_seed2=random();

 	pid = fork();
 	if (pid<0) {
 		lock_release(process_lock);

 		ret=pid;
 		goto end;

 	}
 	if (pid==0){

 		is_main=0; /* a forked process cannot be the "main" one */

 		process_no=child_process_no;

 		/* close unneeded unix sockets */
 		close_extra_socks(child_id, process_no);
 		/* same for unneeded tcp_children <-> tcp_main unix socks */
 		for (i=0; i<r; i++){
 			if (tcp_children[i].unix_sock>=0){
 				close(tcp_children[i].unix_sock);
 				/* tcp_children is per process, so it's safe to change
 				 * the unix_sock to -1 */
 				tcp_children[i].unix_sock=-1;
 			}
 		}

 		srand(new_seed1);

 		fastrand_seed(rand());

 		srandom(new_seed2+time(0));

 		shm_malloc_on_fork();

 #ifdef PROFILING
 		monstartup((u_long) &_start, (u_long) &etext);
 #endif

 #ifdef FORK_DONT_WAIT
 		/* record pid twice to avoid the child using it, before
 -		 * parent gets a chance to set it*/
 		pt[process_no].pid=getpid();
 #else

 		/* wait for parent to get out of critical zone */
 		lock_get(process_lock);
 		lock_release(process_lock);

 #endif
 		close(sockfd[0]);
 		unix_tcp_sock=sockfd[1];
 		close(reader_fd[0]);
 		if (reader_fd_1) *reader_fd_1=reader_fd[1];
 		if ((child_id!=PROC_NOCHLDINIT) && (init_child(child_id) < 0)) {

 			LOG(L_ERR, "ERROR: fork_tcp_process(): init_child failed for "

 					"process %d, pid %d, \"%s\"\n", process_no, 
 					pt[process_no].pid, pt[process_no].desc);

 			return -1;
 		}
 		return pid;
 	} else {

 		/* parent */
 		(*process_count)++;
 #ifdef FORK_DONT_WAIT
 		lock_release(process_lock);
 #endif

 		/* add the process to the list in shm */

 		pt[child_process_no].pid=pid;
 		pt[child_process_no].unix_sock=sockfd[0];
 		pt[child_process_no].idx=r;

 		if (desc){

 			snprintf(pt[child_process_no].desc, MAX_PT_DESC, "%s child=%d", 

 						desc, r);
 		}

 #ifdef FORK_DONT_WAIT
 #else
 		lock_release(process_lock);
 #endif

 		
 		close(sockfd[1]);
 		close(reader_fd[1]);
 		
 		tcp_children[r].pid=pid;

 		tcp_children[r].proc_no=child_process_no;

 		tcp_children[r].busy=0;
 		tcp_children[r].n_reqs=0;
 		tcp_children[r].unix_sock=reader_fd[0];
 		

 		ret=pid;
 		goto end;

 	}

 error:
 	if (sockfd[0]!=-1) close(sockfd[0]);
 	if (sockfd[1]!=-1) close(sockfd[1]);
 	if (reader_fd[0]!=-1) close(reader_fd[0]);
 	if (reader_fd[1]!=-1) close(reader_fd[1]);
 end:
 	return ret;

 }

 #endif

 
 #ifdef PKG_MALLOC
 /* Dumps pkg memory status.
  * Per-child process callback that is called
  * when mem_dump_pkg cfg var is changed.
  */

 void mem_dump_pkg_cb(str *gname, str *name)

 {
 	int	old_memlog;
 
 	if (cfg_get(core, core_cfg, mem_dump_pkg) == my_pid()) {
 		/* set memlog to ALERT level to force
 		printing the log messages */
 		old_memlog = memlog;
 		memlog = L_ALERT;
 
 		LOG(memlog, "Memory status (pkg) of process %d:\n", my_pid());
 		pkg_status();
 
 		memlog = old_memlog;
 	}
 }
 #endif
 
 #ifdef SHM_MEM
 /* Dumps shm memory status.
  * fixup function that is called
  * when mem_dump_shm cfg var is set.
  */

 int mem_dump_shm_fixup(void *handle, str *gname, str *name, void **val)

 {
 	int	old_memlog;
 
 	if ((long)(void*)(*val)) {
 		/* set memlog to ALERT level to force
 		printing the log messages */
 		old_memlog = memlog;
 		memlog = L_ALERT;
 
 		LOG(memlog, "Memory status (shm)\n");
 		shm_status();
 
 		memlog = old_memlog;
 		*val = (void*)(long)0;
 	}
 	return 0;
 }
 #endif