/*
 *
 * ocf_ipc.c: IPC abstraction implementation.
 *
 *
 * Copyright (c) 2002 Xiaoxiang Liu <xiliu@ncsa.uiuc.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
#include <lha_internal.h>
#include <clplumbing/ipc.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/poll.h>
#include <clplumbing/cl_log.h>
#include <sys/types.h>
#include <unistd.h>
#include <ctype.h>
#include <pwd.h>
#include <grp.h>

static int num_pool_allocated = 0;
static int num_pool_freed = 0;

#ifdef IPC_TIME_DEBUG
struct ha_msg;
void cl_log_message (int log_level, const struct ha_msg *m);
int  timediff(longclock_t t1, longclock_t t2);
void   ha_msg_del(struct ha_msg* msg);
void	ipc_time_debug(IPC_Channel* ch, IPC_Message* ipcmsg, int whichpos);
#endif

struct IPC_WAIT_CONNECTION * socket_wait_conn_new(GHashTable* ch_attrs);
struct IPC_CHANNEL * socket_client_channel_new(GHashTable* ch_attrs);

int (*ipc_pollfunc_ptr)(struct pollfd*, unsigned int, int)
=	(int (*)(struct pollfd*, unsigned int, int)) poll;

/* Set the IPC poll function to the given function */
void
ipc_set_pollfunc(int (*pf)(struct pollfd*, unsigned int, int))
{
	ipc_pollfunc_ptr = pf;
}

struct IPC_WAIT_CONNECTION *
ipc_wait_conn_constructor(const char * ch_type, GHashTable* ch_attrs)
{
  if (strcmp(ch_type, "domain_socket") == 0
  ||	strcmp(ch_type, IPC_UDS_CRED) == 0
  ||	strcmp(ch_type, IPC_ANYTYPE) == 0
  ||	strcmp(ch_type, IPC_DOMAIN_SOCKET) == 0) {
    return socket_wait_conn_new(ch_attrs);
  }
  return NULL;
}

struct IPC_CHANNEL *
ipc_channel_constructor(const char * ch_type, GHashTable* ch_attrs)
{
  if	(strcmp(ch_type, "domain_socket") == 0
  ||	strcmp(ch_type, IPC_UDS_CRED) == 0
  ||	strcmp(ch_type, IPC_ANYTYPE) == 0
  ||	strcmp(ch_type, IPC_DOMAIN_SOCKET) == 0) {

	return socket_client_channel_new(ch_attrs);
  }
  return NULL;
}

static int
gnametonum(const char * gname, int gnlen)
{
	char	grpname[64];
	struct group*	grp;

	if (isdigit((int) gname[0])) {
		return atoi(gname);
	}
	if (gnlen >= (int)sizeof(grpname)) {
		return -1;
	}
	strncpy(grpname, gname, gnlen);
	grpname[gnlen] = EOS;
	if ((grp = getgrnam(grpname)) == NULL) {
		cl_log(LOG_ERR
		,	"Invalid group name [%s]", grpname);
		return -1;
	}
	return (int)grp->gr_gid;
}

static int
unametonum(const char * lname, int llen)
{
	char	loginname[64];
	struct passwd*	pwd;

	if (llen >= (int)sizeof(loginname)) {
		cl_log(LOG_ERR
		,	"user id name [%s] is too long", loginname);
		return -1;
	}
	strncpy(loginname, lname, llen);
	loginname[llen] = EOS;

	if (isdigit((int) loginname[0])) {
		return atoi(loginname);
	}
	if ((pwd = getpwnam(loginname)) == NULL) {
		cl_log(LOG_ERR
		,	"Invalid user id name [%s]", loginname);
		return -1;
	}
	return (int)pwd->pw_uid;
}

static GHashTable*
make_id_table(const char * list, int listlen, int (*map)(const char *, int))
{
	GHashTable*	ret;
	const char *	id;
	const char *	lastid = list + listlen;
	int		idlen;
	int		idval;
	static int	one = 1;

	ret = g_hash_table_new(g_direct_hash, g_direct_equal);

	id = list;
	while (id < lastid && *id != EOS) {
		idlen = strcspn(id, ",");
		if (id+idlen >= lastid) {
			idlen = (lastid - id);
		}
		idval = map(id, idlen);
		if (idval < 0) {
			g_hash_table_destroy(ret);
			return NULL;
		}
#if 0
		cl_log(LOG_DEBUG
		,       "Adding [ug]id %*s [%d] to authorization g_hash_table"
		,	idlen, id, idval);
#endif
		g_hash_table_insert(ret, GUINT_TO_POINTER(idval), &one);
		id += idlen;
		if (id < lastid) {
			id += strspn(id, ",");
		}
	}
	return ret;
}

struct IPC_AUTH*
ipc_str_to_auth(const char* uidlist, int uidlen, const char* gidlist, int gidlen)
{
	struct IPC_AUTH* auth;

	auth = malloc(sizeof(struct IPC_AUTH));
	if (auth == NULL) {
		cl_log(LOG_ERR, "Out of memory for IPC_AUTH");
		return NULL;
	}

	memset(auth, 0, sizeof(*auth));

	if (uidlist) {
		auth->uid = make_id_table(uidlist, uidlen, unametonum);
		if (auth->uid == NULL) {
			cl_log(LOG_ERR,
			       "Bad uid list [%*s]",
			       uidlen, uidlist);
			goto errout;
		}
	}
	if (gidlist) {
		auth->gid = make_id_table(gidlist, gidlen, gnametonum);
		if (auth->gid == NULL) {
			cl_log(LOG_ERR ,
			       "Bad gid list [%*s]",
			       gidlen, gidlist);
			goto errout;
		}
	}
	return auth;

 errout:
	if (auth->uid) {
		g_hash_table_destroy(auth->uid);
		auth->uid = NULL;
	}
	if (auth->gid) {
		g_hash_table_destroy(auth->gid);
		auth->gid = NULL;
	}
	free(auth);
	auth = NULL;
	return NULL;
}

struct IPC_AUTH *
ipc_set_auth(uid_t * a_uid, gid_t * a_gid, int num_uid, int num_gid)
{
  struct IPC_AUTH *temp_auth;
  int i;
  static int v = 1;

  temp_auth = malloc(sizeof(struct IPC_AUTH));
  if (temp_auth == NULL) {
	  cl_log(LOG_ERR, "%s: memory allocation failed",__FUNCTION__);
	  return NULL;
  }
  temp_auth->uid = g_hash_table_new(g_direct_hash, g_direct_equal);
  temp_auth->gid = g_hash_table_new(g_direct_hash, g_direct_equal);

  if (num_uid > 0) {
    for (i=0; i<num_uid; i++) {
      g_hash_table_insert(temp_auth->uid, GINT_TO_POINTER((gint)a_uid[i])
      ,		&v);
    }
  }

  if (num_gid > 0) {
    for (i=0; i<num_gid; i++) {
      g_hash_table_insert(temp_auth->gid, GINT_TO_POINTER((gint)a_gid[i])
      ,		&v);
    }
  }

  return temp_auth;
}

void
ipc_destroy_auth(struct IPC_AUTH *auth)
{
	if (auth != NULL) {
		if (auth->uid) {
			g_hash_table_destroy(auth->uid);
		}
		if (auth->gid) {
			g_hash_table_destroy(auth->gid);
		}
		free((void *)auth);
	}
}

static void
ipc_bufpool_display(struct ipc_bufpool* pool)
{
	if (pool == NULL) {
		return;
	}
	cl_log(LOG_INFO, "pool: refcount=%d, startpos=%p, currpos=%p,"
	       "consumepos=%p, endpos=%p, size=%d",
	       pool->refcount, pool->startpos,
	       pool->currpos, pool->consumepos,
	       pool->endpos, pool->size);
}

void
ipc_bufpool_dump_stats(void)
{
	cl_log(LOG_INFO, "num_pool_allocated=%d, num_pool_freed=%d, diff=%d",
	       num_pool_allocated,
	       num_pool_freed,
	       num_pool_allocated - num_pool_freed);
}

#define POOLHDR_SIZE \
	(sizeof(struct ipc_bufpool) + 2*sizeof(struct SOCKET_MSG_HEAD))

struct ipc_bufpool*
ipc_bufpool_new(int size)
{
	struct ipc_bufpool* pool;
	int	totalsize;

	/* there are memories for two struct SOCKET_MSG_HEAD
	 * one for the big message, the other one for the next
	 * message. This code prevents allocating
	 *	<big memory> <4k> <big memory><4k> ...
	 * from happening when a client sends big messages
	 * constantly*/

	totalsize = size + POOLHDR_SIZE;

	if (totalsize < POOL_SIZE) {
		totalsize = POOL_SIZE;
	}

	if (totalsize > MAXMSG + POOLHDR_SIZE) {
		cl_log(LOG_INFO, "ipc_bufpool_new: "
		       "asking for buffer with size %d; "
		       "corrupted data len???", totalsize);
		return NULL;
	}

	pool = (struct ipc_bufpool*)malloc(totalsize+1);
	if (pool == NULL) {
		cl_log(LOG_ERR, "%s: memory allocation failed", __FUNCTION__);
		return NULL;
	}
	memset(pool, 0, totalsize);
	pool->refcount = 1;
	pool->startpos = pool->currpos = pool->consumepos =
		((char*)pool) + sizeof(struct ipc_bufpool);

	pool->endpos = ((char*)pool)  + totalsize;
	pool->size = totalsize;

	num_pool_allocated ++ ;

	return pool;
}

void
ipc_bufpool_del(struct ipc_bufpool* pool)
{
	if (pool == NULL) {
		return;
	}

	if (pool->refcount > 0) {
		cl_log(LOG_ERR," ipc_bufpool_del:"
		       " IPC buffer pool reference count > 0");
		return;
	}

	memset(pool, 0, pool->size);
	free(pool);
	num_pool_freed ++ ;
}

int
ipc_bufpool_spaceleft(struct ipc_bufpool* pool)
{
	if( pool == NULL) {
		cl_log(LOG_ERR, "ipc_bufpool_spaceleft:"
		       " invalid input argument");
		return 0;
	}
	return pool->endpos - pool->currpos;
}

/* brief free the memory space allocated to msg and destroy msg. */

static void
ipc_bufpool_msg_done(struct IPC_MESSAGE * msg)
{
	struct ipc_bufpool* pool;

	if (msg == NULL) {
		cl_log(LOG_ERR, "ipc_bufpool_msg_done: invalid input");
		return;
	}

	pool = (struct ipc_bufpool*)msg->msg_private;

	ipc_bufpool_unref(pool);
	free(msg);
}

static struct IPC_MESSAGE*
ipc_bufpool_msg_new(void)
{
	struct IPC_MESSAGE * temp_msg;

	temp_msg = malloc(sizeof(struct IPC_MESSAGE));
	if (temp_msg == NULL) {
		cl_log(LOG_ERR, "ipc_bufpool_msg_new:"
		       "allocating new msg failed");
		return NULL;
	}

	memset(temp_msg, 0, sizeof(struct IPC_MESSAGE));

	return temp_msg;
}

static void
ipcmsg_display(IPC_Message* ipcmsg)
{
	if (ipcmsg == NULL) {
		cl_log(LOG_ERR, "ipcmsg is NULL");
		return;
	}
	cl_log(LOG_INFO, "ipcmsg: msg_len=%lu, msg_buf=%p, msg_body=%p,"
	       "msg_done=%p, msg_private=%p, msg_ch=%p",
	       (unsigned long)ipcmsg->msg_len,
	       ipcmsg->msg_buf,
	       ipcmsg->msg_body,
	       ipcmsg->msg_done,
	       ipcmsg->msg_private,
	       ipcmsg->msg_ch);
}

/* after a recv call, we have new data
 * in the pool buf, we need to update our
 * pool struct to consume it
 *
 */

int
ipc_bufpool_update(struct ipc_bufpool* pool,
		   struct IPC_CHANNEL * ch,
		   int msg_len,
		   IPC_Queue* rqueue)
{
	IPC_Message*			ipcmsg;
	struct SOCKET_MSG_HEAD		localhead;
	struct SOCKET_MSG_HEAD*		head = &localhead;
	int				nmsgs = 0 ;

	if (rqueue == NULL) {
		cl_log(LOG_ERR, "ipc_update_bufpool:"
		       "invalid input");
		return 0;
	}

	pool->currpos += msg_len;

	while(TRUE) {
		/*not enough data for head*/
		if ((int)(pool->currpos - pool->consumepos) < (int)ch->msgpad) {
			break;
		}

		memcpy(head, pool->consumepos, sizeof(struct SOCKET_MSG_HEAD));

		if (head->magic != HEADMAGIC) {
			GList* last = g_list_last(rqueue->queue);
			cl_log(LOG_ERR, "ipc_bufpool_update: "
			       "magic number in head does not match. "
			       "Something very bad happened, farside pid =%d",
			       ch->farside_pid);
			cl_log(LOG_ERR, "magic=%x, expected value=%x", head->magic, HEADMAGIC);
			ipc_bufpool_display(pool);
			cl_log(LOG_INFO, "nmsgs=%d", nmsgs);
			/*print out the last message in queue*/
			if (last) {
				IPC_Message* m = (IPC_Message*)last;
				ipcmsg_display(m);
			}
			return -1;
		}

		if ( head->msg_len > MAXMSG) {
			cl_log(LOG_ERR, "ipc_update_bufpool:"
			       "msg length is corruptted(%d)",
			       head->msg_len);
			break;
		}

		if (pool->consumepos + ch->msgpad + head->msg_len
		    > pool->currpos) {
			break;
		}

		ipcmsg = ipc_bufpool_msg_new();
		if (ipcmsg == NULL) {
			cl_log(LOG_ERR, "ipc_update_bufpool:"
			       "allocating memory for new ipcmsg failed");
			break;

		}
		ipcmsg->msg_buf = pool->consumepos;
		ipcmsg->msg_body = pool->consumepos + ch->msgpad;
		ipcmsg->msg_len = head->msg_len;
		ipcmsg->msg_private = pool;
		ipcmsg->msg_done = ipc_bufpool_msg_done;
#ifdef IPC_TIME_DEBUG
		ipc_time_debug(ch,ipcmsg, MSGPOS_RECV);
#endif
		rqueue->queue = g_list_append(rqueue->queue, ipcmsg);
		rqueue->current_qlen ++;
		nmsgs++;

		pool->consumepos += ch->msgpad + head->msg_len;
		ipc_bufpool_ref(pool);
	}
	return nmsgs;
}

gboolean
ipc_bufpool_full(struct ipc_bufpool* pool,
		 struct IPC_CHANNEL* ch,
		 int* dataspaceneeded)
{
	struct SOCKET_MSG_HEAD  localhead;
	struct SOCKET_MSG_HEAD* head = &localhead;

	*dataspaceneeded = 0;
	/* not enough space for head */
	if ((int)(pool->endpos - pool->consumepos) < (int)ch->msgpad) {
		return TRUE;
	}

	/*enough space for head*/
	if ((int)(pool->currpos - pool->consumepos) >= (int)ch->msgpad) {
		memcpy(head, pool->consumepos, sizeof(struct SOCKET_MSG_HEAD));

		/* not enough space for data*/
		if ( pool->consumepos + ch->msgpad + head->msg_len >= pool->endpos) {
			*dataspaceneeded = head->msg_len;
			return TRUE;
		}
	}

	/* Either we are sure we have enough space
	 * or we cannot tell because we have not received
	 * head yet. But we are sure we have enough space
	 * for head
	 */
	return FALSE;
}

int
ipc_bufpool_partial_copy(struct ipc_bufpool* dstpool,
			      struct ipc_bufpool* srcpool)
{
	struct SOCKET_MSG_HEAD	localhead;
	struct SOCKET_MSG_HEAD *head = &localhead;
	int space_needed;
	int nbytes;

	if (dstpool == NULL
	    || srcpool == NULL) {
		cl_log(LOG_ERR, "ipc_bufpool_partial_ipcmsg_cp:"
		       "invalid input");
		return IPC_FAIL;
	}

	if (srcpool->currpos - srcpool->consumepos >=
	    (ssize_t)sizeof(struct SOCKET_MSG_HEAD)) {

		memcpy(head, srcpool->consumepos, sizeof(struct SOCKET_MSG_HEAD));
		space_needed = head->msg_len + sizeof(*head);

		if (space_needed >  ipc_bufpool_spaceleft(dstpool)) {
			cl_log(LOG_ERR, "ipc_bufpool_partial_ipcmsg_cp:"
			       " not enough space left in dst pool,spaced needed=%d",
			       space_needed);
			return IPC_FAIL;
		}
	}

	nbytes = srcpool->currpos - srcpool->consumepos;
	memcpy(dstpool->consumepos, srcpool->consumepos,nbytes);

	srcpool->currpos = srcpool->consumepos;
	dstpool->currpos = dstpool->consumepos + nbytes;

	return IPC_OK;
}

void
ipc_bufpool_ref(struct ipc_bufpool* pool)
{
	if (pool == NULL) {
		cl_log(LOG_ERR, "ref_pool:"
		       " invalid input");
		return;
	}
	pool->refcount ++;
}

void
ipc_bufpool_unref(struct ipc_bufpool* pool)
{
	if (pool == NULL) {
		cl_log(LOG_ERR, "unref_pool:"
		       " invalid input");
		return;
	}
	pool->refcount --;
	if (pool->refcount <= 0) {
		ipc_bufpool_del(pool);
	}
}