conn.c

/*
	libxbee - a C/C++ library to aid the use of Digi's XBee wireless modules
	          running in API mode.

	Copyright (C) 2009 onwards  Attie Grande (attie@attie.co.uk)

	libxbee 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 3 of the License, or
	(at your option) any later version.

	libxbee 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 libxbee. If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "internal.h"
#include "xbee_int.h"
#include "conn.h"
#include "pkt.h"
#include "mode.h"
#include "log.h"
#include "thread.h"
#include "frame.h"
#include "tx.h"
#include "ll.h"

struct xbee_ll_head *conList = NULL;

/* ########################################################################## */
static xbee_err _xbee_conFree(struct xbee_con *con);

xbee_err xbee_conAlloc(struct xbee_con **nCon) {
	size_t memSize;
	struct xbee_con *con;
	xbee_err ret;
	
	if (!nCon) return XBEE_EMISSINGPARAM;
	
	memSize = sizeof(*con);
	
	if (!(con = malloc(memSize))) return XBEE_ENOMEM;
	
	memset(con, 0, memSize);
	con->pktList = xbee_ll_alloc();
	xsys_sem_init(&con->callbackSem);
	xsys_mutex_init(&con->txMutex);
	
	if ((ret = xbee_ll_add_tail(conList, con)) != XBEE_ENONE) {
		_xbee_conFree(con);
		ret = XBEE_ELINKEDLIST;
	} else {
		*nCon = con;
	}
	
	return ret;
}

xbee_err xbee_conFree(struct xbee_con *con) {
	xbee_err ret;
	
	if (!con) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	xbee_conUnlink(con);

	if (con->callbackThread) {
		con->ending = 1;
		xsys_sem_post(&con->callbackSem);
		if ((ret = xbee_threadJoin(con->xbee, con->callbackThread, NULL)) != XBEE_ENONE) {
			int i;
			if (ret != XBEE_EINUSE) return ret;
			
			/* wait patiently upto 50ms for the callback to finish its stuff */
			for (i = 10; i > 0; i--) {
				usleep(5000);
				if ((ret = xbee_threadJoin(con->xbee, con->callbackThread, NULL)) == XBEE_ENONE) break;
				if (ret == XBEE_EINUSE) continue;
				return ret;
			}
			
			/* if it's still not dead, then just kill it! */
			if (i == 0 && (ret = xbee_threadKillJoin(con->xbee, con->callbackThread, NULL)) != XBEE_ENONE) return ret;
		}
		con->callbackThread = NULL;
	}
	
	return _xbee_conFree(con);
}
	
static xbee_err _xbee_conFree(struct xbee_con *con) {
	xbee_ll_ext_item(conList, con);
	
	xbee_mutex_lock(&con->txMutex);
	
	xsys_mutex_destroy(&con->txMutex);
	xsys_sem_destroy(&con->callbackSem);
	xbee_ll_free(con->pktList, (void(*)(void*))xbee_pktFree);
	
	free(con);
	
	return XBEE_ENONE;
}

/* ########################################################################## */

xbee_err xbee_conLink(struct xbee *xbee, struct xbee_modeConType *conType, struct xbee_conAddress *address, struct xbee_con *con) {
	xbee_err ret;
	unsigned char matchRating;

	if (!xbee || !conType || !con) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_validate(xbee) != XBEE_ENONE) return XBEE_EINVAL;
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	ret = XBEE_ENONE;
	xbee_ll_lock(conType->conList);
	
	do {
		if ((ret = _xbee_ll_get_item(conType->conList, con, 0)) != XBEE_ENOTEXISTS) {
			if (ret == XBEE_ENONE) {
				ret = XBEE_EEXISTS;
			}
			break;
		}
		
		if ((ret = _xbee_conLocate(conType->conList, address, &matchRating, NULL, -1, 0)) != XBEE_ENOTEXISTS && 
		     ret != XBEE_ESLEEPING &&
		     ret != XBEE_ECATCHALL) {
			if (ret == XBEE_ENONE && matchRating == 255) {
				ret = XBEE_EEXISTS;
				break;
			}
		}
	
		if ((ret = _xbee_ll_add_tail(conType->conList, con, 0)) != XBEE_ENONE) {
			break;
		}
		
		con->xbee = xbee;
		con->conType = conType;
	} while (0);
	
	xbee_ll_unlock(conType->conList);
	
	return ret;
}

xbee_err xbee_conUnlink(struct xbee_con *con) {
	struct xbee *xbee;
	struct xbee_modeConType *conType;
	xbee_err ret;
	if (!con) return XBEE_EMISSINGPARAM;
	xbee = con->xbee;
	conType = con->conType;
	if (!xbee || !conType) return XBEE_EINVAL;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_validate(xbee) != XBEE_ENONE) return XBEE_EINVAL;
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	if ((ret = xbee_ll_ext_item(conType->conList, con)) != XBEE_ENONE) return ret;
	
	return ret;
}

/* ########################################################################## */

xbee_err xbee_conLogAddress(struct xbee *xbee, int minLogLevel, struct xbee_conAddress *address) {
	if (!address) return XBEE_EINVAL;
	xbee_log(minLogLevel, "address @ %p...", address);
	xbee_log(minLogLevel, "   broadcast:      %s", (address->broadcast)?"Yes":"No");
	if (address->addr16_enabled) {
		xbee_log(minLogLevel, "   16-bit address:  0x%02X%02X", address->addr16[0], address->addr16[1]);
	} else {
		xbee_log(minLogLevel, "   16-bit address:  --");
	}
	if (address->addr64_enabled) {
		xbee_log(minLogLevel, "   64-bit address:  0x%02X%02X%02X%02X 0x%02X%02X%02X%02X",
		                      address->addr64[0], address->addr64[1], address->addr64[2], address->addr64[3],
		                      address->addr64[4], address->addr64[5], address->addr64[6], address->addr64[7]);
	} else {
		xbee_log(minLogLevel, "   64-bit address:  --");
	}
	if (address->endpoints_enabled) {
		xbee_log(minLogLevel, "   endpoints:       local(0x%02X) remote(0x%02X)", address->endpoint_local, address->endpoint_remote);
	} else {
		xbee_log(minLogLevel, "   endpoints:       --");
	}
	if (address->profile_enabled) {
		xbee_log(minLogLevel, "   profile ID:      0x%04X", address->profile_id);
	} else {
		xbee_log(minLogLevel, "   profile ID:      ----");
	}
	if (address->cluster_enabled) {
		xbee_log(minLogLevel, "   cluster ID:      0x%04X", address->cluster_id);
	} else {
		xbee_log(minLogLevel, "   cluster ID:      ----");
	}
	return XBEE_ENONE;
}

/* ######################################################################### */

/* this function is ONLY to be assigned to the conType struct's 'addressPrep' function pointer...
   this function contains logic that works for the basic XBee series modules, but not the more advanced ones (e.g: WiFi) */
xbee_err xbee_conAddressPrepDefault(struct xbee_conAddress *addr) {
	if (!addr) return XBEE_EMISSINGPARAM;
	/* figure out if this is a broadcast address */
	addr->broadcast = 0;
	if (addr->addr16_enabled) {
		if (addr->addr16[0] == 0x00 &&
		    addr->addr16[1] == 0xFF) {
			addr->broadcast = 1;
		}
	} else if (addr->addr64_enabled) {
		unsigned char a[8] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF };
		if (!memcmp(a, addr->addr64, sizeof(a))) {
			addr->broadcast = 1;
		}
	}
	return XBEE_ENONE;
}

/* this function is ONLY to be assigned to the conType struct's 'addressCmp' function pointer...
   this function contains logic that works for the basic XBee series modules, but not the more advanced ones (e.g: WiFi) */
xbee_err xbee_conAddressCmpDefault(struct xbee_conAddress *addr1, struct xbee_conAddress *addr2, unsigned char *matchRating) {
	if (matchRating != NULL) *matchRating = 0;

	/** first try to match the address **/
	/* no 16/64 bit addresses */
	if (!addr1->addr16_enabled && !addr2->addr16_enabled &&
	    !addr1->addr64_enabled && !addr2->addr64_enabled) {
		goto got1;
	}
	/* both have 64 bit addresses (over rules 16bit addressed) */
	if (addr1->addr64_enabled && addr2->addr64_enabled) {
		if (!memcmp(addr1->addr64, addr2->addr64, 8)) goto got1;
		if (addr1->broadcast && addr2->broadcast) {
			if (matchRating != NULL) *matchRating = 1;
			goto got1;
		}
	}
	/* both have 16 bit addresses */
	if (addr1->addr16_enabled && addr2->addr16_enabled) {
		if (!memcmp(addr1->addr16, addr2->addr16, 2)) goto got1;
		if (addr1->broadcast && addr2->broadcast) {
			if (matchRating != NULL) *matchRating = 1;
			goto got1;
		}
	}
	
	return XBEE_EFAILED; /* --- no address match --- */
	
got1:
	/** next try to match the endpoints **/
	/* no endpoints */
	if (!addr1->endpoints_enabled && !addr2->endpoints_enabled) goto got2;
	/* both have endpoints */
	if (addr1->endpoints_enabled && addr2->endpoints_enabled) {
		if (addr1->endpoint_local == addr2->endpoint_local) goto got2;
#warning TODO - handle broadcast endpoint, but probably not here...
	}
	
	return XBEE_EFAILED; /* --- endpoints didn't match --- */
	
got2:
	/** try to match the profile id **/
	/* no profile IDs */
	if (!addr1->profile_enabled && !addr2->profile_enabled) goto got3;
	/* both have profile IDs */
	if (addr1->profile_enabled && addr2->profile_enabled) {
		if (addr1->profile_id == addr2->profile_id) goto got3;
	/* if only one has a profile ID, then is it using the default profile? */
	} else if (addr1->profile_enabled) {
		if (addr1->profile_id == 0xC105) goto got3;
	} else if (addr2->profile_enabled) {
		if (addr2->profile_id == 0xC105) goto got3;
	}
	
	return XBEE_EFAILED; /* --- profile id didn't match / isn't the default (0xC105) */
	
got3:
	/** try to match cluster id **/
	/* no cluster IDs */
	if (!addr1->cluster_enabled && !addr2->cluster_enabled) goto got4;
	/* both have cluster IDs */
	if (addr1->cluster_enabled && addr2->cluster_enabled) {
		if (addr1->cluster_id == addr2->cluster_id) goto got4;
	/* if only one has a cluster ID, then is it using the default cluster? */
	} else if (addr1->cluster_enabled) {
		if (addr1->cluster_id == 0x0011) goto got4;
	} else if (addr2->cluster_enabled) {
		if (addr2->cluster_id == 0x0011) goto got4;
	}
	
	return XBEE_EFAILED; /* --- cluster id didn't match / isn't the default (0x0011) */
	
got4:
	if (matchRating != NULL && *matchRating == 0) *matchRating = 255;
	return XBEE_ENONE;   /* --- everything matched --- */
}

/* ######################################################################### */

xbee_err _xbee_conLocate(struct xbee_ll_head *conList, struct xbee_conAddress *address, unsigned char *retRating, struct xbee_con **retCon, enum xbee_conSleepStates alertLevel, int needsLLLock) {
	/* higher is better!
	   a value of 255 indicates that there will DEFINATELY not be a better match
	   a value of 0 means 'no match' */
	unsigned char matchRating;
	struct xbee_con *con;
	struct xbee_con *sCon; /* <-- Sleeping connection */
	struct xbee_con *cCon; /* <-- 'catchAll' */

	/* tempoary stuff */
	unsigned char tRating;
	struct xbee_con *tCon;

	xbee_err ret;
	
	if (!conList || !address) return XBEE_EMISSINGPARAM;
	
	tRating = 0;
	matchRating = 0;
	con = NULL;
	sCon = NULL;
	cCon = NULL;
	
	if (needsLLLock) xbee_ll_lock(conList);
	for (tCon = NULL; (ret = _xbee_ll_get_next(conList, tCon, (void**)&tCon, 0)) == XBEE_ENONE && tCon; ) {

		/* skip ending connections */
		if (tCon->ending) continue;
		
		/* next see if the connection and can be woken */
		if (tCon->sleepState > alertLevel) continue; /* this connection is outside the 'acceptable wake limit' */
		
		/* keep track of the latest catch-all */
		if (tCon->settings.catchAll) cCon = tCon;
		
		/* try to match the address */
		if (tCon->conType->addressCmp(&tCon->address, address, &tRating) != XBEE_ENONE) continue;
		if (tRating == 0) continue;
		
		/* is the connection dozing? */
		if (tCon->sleepState != CON_AWAKE) {
			/* this is designed to get the most recently created sleeping connection, NOT THE FIRST FOUND */
			sCon = tCon;
			continue;
		}

		/* keep the best rated connection */
		if (tRating > matchRating) {
			matchRating = tRating;
			con = tCon;
		}
		
		if (matchRating == 255) {
			/* found a willing participant, and it was indicated that it would be the best match! */
			break;
		}
	}
	if (needsLLLock) xbee_ll_unlock(conList);
	
	/* did we find a sleepy/catchall connection? */
	if (!con) {
		if (sCon) {
			con = sCon;
			ret = XBEE_ESLEEPING;
		} else if (cCon) {
			con = cCon;
			ret = XBEE_ECATCHALL;
		}
	} else {
		ret = XBEE_ENONE;
	}

	if (!con) return XBEE_ENOTEXISTS;
	
	if (retCon) *retCon = con;
	if (retRating) *retRating = matchRating;
	
	return ret;
}
xbee_err xbee_conLocate(struct xbee_ll_head *conList, struct xbee_conAddress *address, struct xbee_con **retCon, enum xbee_conSleepStates alertLevel) {
	return _xbee_conLocate(conList, address, NULL, retCon, alertLevel, 1);
}

/* ########################################################################## */

EXPORT xbee_err xbee_conGetTypes(struct xbee *xbee, char ***retList) {
	int i, o, p;
	size_t memSize;
	char **tList;
	char *tName;
	struct xbee_modeConType *conTypes;
	if (!xbee || !retList) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_validate(xbee) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */

	if (!xbee->iface.conTypes) return XBEE_EINVAL;

	conTypes = xbee->iface.conTypes;

	memSize = 0;
	p = 0;
	for (i = 0; conTypes[i].name; i++) {
		if (conTypes[i].internal) continue;
		memSize += sizeof(char *);
		memSize += sizeof(char) * (strlen(conTypes[i].name) + 1);
		p++;
	}
	memSize += sizeof(char *);

	if ((tList = malloc(memSize)) == NULL) {
		return XBEE_ENOMEM;
	}

	tName = (char *)&(tList[p+1]);
	o = p;
	p = 0;
	for (i = 0; conTypes[i].name && p < o; i++) {
		if (conTypes[i].internal) continue;
		tList[p] = tName;
		strcpy(tName, conTypes[i].name);
		tName += strlen(tName) + 1;
		p++;
	}
	tList[p] = NULL;

	*retList = tList;

	return XBEE_ENONE;
}

/* ########################################################################## */

xbee_err _xbee_conNew(struct xbee *xbee, struct xbee_interface *iface, int allowInternal, struct xbee_con **retCon, const char *type, struct xbee_conAddress *address) {
	xbee_err ret;
	int conIdentifier;
	struct xbee_con *con;
	struct xbee_modeConType *conType;

	if (!xbee || !iface || !iface->conTypes || !retCon || !type) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_validate(xbee) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	if ((ret = xbee_modeLocateConType(iface->conTypes, allowInternal, type, NULL, NULL, &conType)) != XBEE_ENONE) return ret;
	if (!conType) return XBEE_EUNKNOWN;
	
	if (conType->addressPrep && (ret = conType->addressPrep(address)) != XBEE_ENONE)                                    return ret;
	if (conType->addressRules & ADDR_EP_NOTALLOW && ( address &&  address->endpoints_enabled))                          return XBEE_EINVAL;
	if (conType->addressRules & ADDR_EP_REQUIRED && (!address || !address->endpoints_enabled))                          return XBEE_EINVAL;
	if (conType->addressRules & ADDR_64_NOTALLOW && ( address &&  address->addr64_enabled))                             return XBEE_EINVAL;
	if (conType->addressRules & ADDR_16_NOTALLOW && ( address &&  address->addr16_enabled))                             return XBEE_EINVAL;
	if (conType->addressRules & ADDR_64_REQUIRED && (!address || !address->addr64_enabled))                             return XBEE_EINVAL;
	if (conType->addressRules & ADDR_16_REQUIRED && (!address || !address->addr16_enabled))                             return XBEE_EINVAL;
	if (conType->addressRules & ADDR_16OR64      && (!address || !(address->addr16_enabled | address->addr64_enabled))) return XBEE_EINVAL;
	if (conType->addressRules & ADDR_16XOR64     && (!address || !(address->addr16_enabled ^ address->addr64_enabled))) return XBEE_EINVAL;
	
	conIdentifier = 0;
	if (xbee->mode->support.conNew) {
		/* check with support system */
		if ((ret = xbee->mode->support.conNew(xbee, iface, conType, address, &conIdentifier)) != XBEE_ENONE) return ret;
	}
	
	if ((ret = xbee_conAlloc(&con)) != XBEE_ENONE) return ret;
	con->iface = iface;
	con->conIdentifier = conIdentifier;
	
	if (address) {
		memcpy(&con->address, address, sizeof(*address));
	} else {
		memset(&con->address, 0, sizeof(*address));
	}
	
	if ((ret = xbee_conLink(xbee, conType, &con->address, con)) != XBEE_ENONE) {
		xbee_conFree(con);
		return ret;
	}
	
	xbee_log(6, "Created new '%s' type connection", conType->name);
	xbee_conLogAddress(xbee, 8, address);
	
	*retCon = con;
	
	return XBEE_ENONE;
}
EXPORT xbee_err xbee_conNew(struct xbee *xbee, struct xbee_con **retCon, const char *type, struct xbee_conAddress *address) {
	return _xbee_conNew(xbee, &xbee->iface, 0, retCon, type, address);
}

EXPORT xbee_err xbee_conValidate(struct xbee_con *con) {
	xbee_err ret;
	
	if (xbee_ll_get_item(conList, con) != XBEE_ENONE) return XBEE_EINVAL;
	
	if (con->xbee && con->xbee->mode->support.conValidate) {
		/* check with support system */
		if ((ret = con->xbee->mode->support.conValidate(con)) != XBEE_ENONE) return ret;
	}
	return XBEE_ENONE;
}

EXPORT xbee_err xbee_conGetXBee(struct xbee_con *con, struct xbee **xbee) {
	if (!con || !xbee) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */

	*xbee = con->xbee;

	return XBEE_ENONE;
}

/* ########################################################################## */

xbee_err xbee_conWake(struct xbee_con *con) {
	xbee_err ret;
	unsigned char iRating;
	struct xbee_con *iCon;

	if (!con) return XBEE_EMISSINGPARAM;
	if (!con->conType) return XBEE_EINVAL;
	if (con->sleepState == CON_AWAKE) return XBEE_ENONE;
	
	ret = XBEE_ENONE;
	
	for (iCon = NULL; _xbee_ll_get_next(con->conType->conList, iCon, (void**)&iCon, 0) == XBEE_ENONE && iCon != NULL; ) {
		/* discount ourselves */
		if (iCon == con) continue;
		
		/* try to match the addresses */
		if (con->conType->addressCmp(&con->address, &iCon->address, &iRating) != XBEE_ENONE) continue;
		if (iRating != 255) continue;
		
		/* check if it's awake */
		if (iCon->sleepState != CON_AWAKE) continue;
		
		/* if it is, then we can't wake up */
		ret = XBEE_EFAILED;
		break;
	}
	if (ret == XBEE_ENONE) {
		/* we can wakeup! */
		con->sleepState = CON_AWAKE;
	}
	
	xbee_ll_unlock(con->conType->conList);
	return ret;
}

/* ########################################################################## */

xbee_err _xbee_connxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const unsigned char *buf, int len);
xbee_err _xbee_convxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const char *format, va_list args);

EXPORT xbee_err xbee_conTx(struct xbee_con *con, unsigned char *retVal, const char *format, ...) {
	xbee_err ret;
	va_list ap;
	
	if (!con || !format) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	va_start(ap, format);
	ret = _xbee_convxTx(con, retVal, NULL, format, ap);
	va_end(ap);
	
	return ret;
}
EXPORT xbee_err xbee_conxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const char *format, ...) {
	xbee_err ret;
	va_list ap;
	
	if (!con || !format) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	va_start(ap, format);
	ret = _xbee_convxTx(con, retVal, frameId, format, ap);
	va_end(ap);
	
	return ret;
}

EXPORT xbee_err xbee_convTx(struct xbee_con *con, unsigned char *retVal, const char *format, va_list args) {
	return xbee_convxTx(con, retVal, NULL, format, args);
}
EXPORT xbee_err xbee_convxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const char *format, va_list args) {
	if (!con || !format) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	return _xbee_convxTx(con, retVal, frameId, format, args);
}
xbee_err _xbee_convxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const char *format, va_list args) {
	xbee_err ret;
	int bufLen, outLen;
	char *buf;
	va_list args1;
	
	va_copy(args1, args);
	bufLen = vsnprintf(NULL, 0, format, args1);
	va_end(args1);
	
	if (bufLen > 0) {
		if (!(buf = malloc(bufLen + 1))) { /* +1 for the terminating '\0' */
			return XBEE_ENOMEM;
		}
		outLen = vsnprintf(buf, bufLen + 1, format, args);
		if (outLen > bufLen) {
			ret = XBEE_ERANGE;
			goto die;
		}
	} else {
		buf = NULL;
		outLen = 0;
	}
	
	ret = _xbee_connxTx(con, retVal, frameId, (unsigned char*)buf, outLen);
	
die:
	if (buf) free(buf);
	return ret;
}

EXPORT xbee_err xbee_connTx(struct xbee_con *con, unsigned char *retVal, const unsigned char *buf, int len) {
	return xbee_connxTx(con, retVal, NULL, buf, len);
}
EXPORT xbee_err xbee_connxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const unsigned char *buf, int len) {
	if (!con) return XBEE_EMISSINGPARAM;
	if (len < 0) return XBEE_EINVAL;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	return _xbee_connxTx(con, retVal, frameId, buf, len);
}
xbee_err _xbee_connxTx(struct xbee_con *con, unsigned char *retVal, unsigned char *frameId, const unsigned char *buf, int len) {
	int waitForAck;
	int abandonFrame;
	xbee_err ret;
	unsigned char myret;
	unsigned char *pret;
	
	if (!con) return XBEE_EMISSINGPARAM;
	if (len < 0) return XBEE_EINVAL;

	if (con->sleepState != CON_AWAKE) {
		if (con->sleepState != CON_SNOOZE) {
			/* can't transmit when we are deeper than snooze */
			return XBEE_ESLEEPING;
		}
		if (xbee_conWake(con) != XBEE_ENONE) {
			/* can't transmit while another con is awake */
			return XBEE_ESLEEPING;
		}
	}

	if (!buf) {
		len = 0;
		buf = &((unsigned char){0x00});
	}

	/* we ALWAYS want to be able to check the response value */
	pret = ((!retVal)?&myret:retVal);
	*pret = 0;

	if (con->settings.noBlock) {
		if (xbee_mutex_trylock(&con->txMutex)) return XBEE_EWOULDBLOCK;
	} else {
		xbee_mutex_lock(&con->txMutex);
	}
	abandonFrame = !!con->settings.noWaitForAck;
	
	if (!con->conType->allowFrameId) {
		waitForAck = 0;
		con->frameId = 0;
	} else {
		waitForAck = !(con->settings.disableAck || con->settings.broadcast); /* cache it, incase it changes */
		if (waitForAck) {
			if ((ret = xbee_frameGetFreeID(con->xbee->fBlock, con, abandonFrame)) != XBEE_ENONE) {
				ret = XBEE_ENOFREEFRAMEID;
				goto done;
			}
		} else {
			con->frameId = 0; /* status response disabled */
		}
	}
	if (frameId) *frameId = con->frameId;
	
	if ((ret = xbee_txHandler(con, buf, len, waitForAck)) != XBEE_ENONE) goto done;

	if (waitForAck && !abandonFrame) {
		struct timespec to;
		clock_gettime(CLOCK_REALTIME, &to);
		if (con->conType->useTimeout) {
			to.tv_sec  += con->conType->timeout.tv_sec;
			to.tv_nsec += con->conType->timeout.tv_nsec;
			while (to.tv_nsec >= 1000000000) {
				to.tv_sec++;
				to.tv_nsec -= 1000000000;
			}
		} else {
			to.tv_sec += 1; /* default 1 second timeout */
		}
		if ((ret = xbee_frameWait(con->xbee->fBlock, con, pret, &to)) == XBEE_ENONE) {
			if (*pret != 0) ret = XBEE_ETX;
		}
	}
	
done:
	xbee_mutex_unlock(&con->txMutex);
	
	return ret;
}

/* ########################################################################## */

xbee_err xbee_conLinkPacket(struct xbee_con *con, struct xbee_pkt *pkt) {
	xbee_err ret;
	if (!con || !pkt) return XBEE_EMISSINGPARAM;
	if ((ret = xbee_ll_add_tail(con->pktList, pkt)) != XBEE_ENONE) return ret;
	if (con->callback) return xbee_conCallbackProd(con);
	return XBEE_ENONE;
}

EXPORT xbee_err xbee_conRx(struct xbee_con *con, struct xbee_pkt **retPkt, int *remainingPackets) {
	xbee_err ret;
	unsigned int remain;
	struct xbee_pkt *pkt;
	if (!con) return XBEE_EMISSINGPARAM;
	if (!retPkt && !remainingPackets) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	if (retPkt != NULL && con->callback != NULL) return XBEE_EINVAL;
	
	ret = XBEE_ENONE;
	remain = 0;
	
	xbee_ll_lock(con->pktList);
	if ((ret = _xbee_ll_count_items(con->pktList, &remain, 0)) != XBEE_ENONE) goto die;
	if (retPkt != NULL) {
		if (remain == 0) {
			*retPkt = NULL;
			ret = XBEE_ENOTEXISTS;
			goto die;
		}
		_xbee_ll_ext_head(con->pktList, (void**)&pkt, 0);
		_xbee_pktUnlink(con, pkt, 0);
		*retPkt = pkt;
	}
die:
	xbee_ll_unlock(con->pktList);

	if (remainingPackets) *remainingPackets = (remain > 0 ? remain - 1 : 0);
	
	return ret;
}
EXPORT xbee_err xbee_conRxWait(struct xbee_con *con, struct xbee_pkt **retPkt, int *remainingPackets) {
	xbee_err ret;
	int i;

	ret = XBEE_EUNKNOWN;

	/* 50ms * 20 = 1second */
	for (i = 20; i > 0; i--) {
		/* break on success, or any error other than XBEE_ENOTEXISTS (nothing to Rx) */
		if ((ret = xbee_conRx(con, retPkt, remainingPackets)) != XBEE_ENOTEXISTS) break;
		usleep(50000);
	}

	return ret;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conPurge(struct xbee_con *con) {
	xbee_err ret;
	unsigned int remain;
	struct xbee_pkt *pkt;

	xbee_ll_lock(con->pktList);
	if ((ret = _xbee_ll_count_items(con->pktList, &remain, 0)) != XBEE_ENONE) goto die;
	while (remain > 0) {
		_xbee_ll_ext_head(con->pktList, (void**)&pkt, 0);
		_xbee_pktUnlink(con, pkt, 0);
		xbee_pktFree(pkt);
		if ((ret = _xbee_ll_count_items(con->pktList, &remain, 0)) != XBEE_ENONE) goto die;
	}

die:
	xbee_ll_unlock(con->pktList);
	return ret;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conSleepSet(struct xbee_con *con, enum xbee_conSleepStates state) {
	xbee_err ret;
	if (!con) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	if (con->xbee->mode->support.conSleepSet) {
		/* check with support system */
		if ((ret = con->xbee->mode->support.conSleepSet(con, state)) != XBEE_ENONE) return ret;
	}
	
	ret = XBEE_ENONE;
	
	if (state == CON_AWAKE) {
		/* we need to check if we can wakeup */
		ret = xbee_conWake(con); /* <-- this will set us to awake if it is successful */
	} else {
		con->sleepState = state;
	}
	
	return ret;
}

EXPORT xbee_err xbee_conSleepGet(struct xbee_con *con, enum xbee_conSleepStates *state) {
	xbee_err ret;
	if (!con || !state) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	if (con->xbee->mode->support.conSleepGet) {
		/* check with support system */
		if ((ret = con->xbee->mode->support.conSleepGet(con)) != XBEE_ENONE) return ret;
	}
	
	*state = con->sleepState;
	return XBEE_ENONE;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conDataSet(struct xbee_con *con, void *newData, void **oldData) {
	if (!con) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	if (oldData) *oldData = con->userData;
	con->userData = newData;
	return XBEE_ENONE;
}

EXPORT xbee_err xbee_conDataGet(struct xbee_con *con, void **curData) {
	if (!con || !curData) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	*curData = con->userData;
	return XBEE_ENONE;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conTypeGet(struct xbee_con *con, char **type) {
	if (!con || !type) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	*type = con->conType->name;
	return XBEE_ENONE;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conInfoGet(struct xbee_con *con, struct xbee_conInfo *info) {
	if (!con || !info) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	memcpy(info, &con->info, sizeof(con->info));
	return XBEE_ENONE;
}

/* ########################################################################## */

xbee_err xbee_conCallbackHandler(struct xbee *xbee, int *restart, void *arg) {
	struct xbee_con *con;
	struct xbee_pkt *pkt, *oPkt;
	xbee_err ret;
	xbee_t_conCallback callback;

	con = arg;

	while (!con->ending) {
		callback = con->callback;
		if (!callback) break;
		if ((ret = xbee_ll_ext_head(con->pktList, (void**)&pkt)) == XBEE_ERANGE) {
			struct timespec to;
			clock_gettime(CLOCK_REALTIME, &to);
			to.tv_sec += 5; /* 5 second timeout */
			if (xsys_sem_timedwait(&con->callbackSem, &to)) {
				if (errno == ETIMEDOUT) break;
				return XBEE_ESEMAPHORE;
			}
			continue;
		} else if (ret != XBEE_ENONE) {
			return ret;
		}

		xbee_log(8, "connection @ %p got packet @ %p, about to hand to callback function @ %p...", con, pkt, callback);

		oPkt = pkt;
		callback(xbee, con, &pkt, &con->userData);

		if (pkt) {
			if (pkt == oPkt) {
				xbee_pktFree(pkt);
			} else {
				xbee_log(-1, "callback for connection @ %p returned a different packet to what it was provided...");
			}
		}
	}
	
	*restart = 0;
	return XBEE_ENONE;
}

xbee_err xbee_conCallbackProd(struct xbee_con *con) {
	struct xbee *xbee;
	xbee_err ret;
	unsigned int count;

	if (!con) return XBEE_EMISSINGPARAM;
	if (!con->callback) return XBEE_ENONE;

	if (xbee_ll_count_items(con->pktList, &count) != XBEE_ENONE) return XBEE_ELINKEDLIST;
	if (count == 0) return XBEE_ENONE;

	xbee = con->xbee;

	xsys_sem_post(&con->callbackSem);

	if (con->callbackThread) {
		xbee_err ret2;
		
#warning TODO - there is a gap here, needs a mutex
		if (con->callbackThread->active) return XBEE_ENONE;
		
		if ((ret = xbee_threadJoin(con->xbee, con->callbackThread, &ret2)) != XBEE_ENONE) return ret;
		con->callbackThread = NULL;
		if (ret2 != XBEE_ENONE) {
			xbee_log(3, "dead callback for con @ %p returned %d...", con, ret2);
		}
	}
	
	if ((ret = xbee_threadStart(con->xbee, &con->callbackThread, 0, 0, xbee_conCallbackHandler, con)) != XBEE_ENONE) return ret;
	
	return XBEE_ENONE;
}

EXPORT xbee_err xbee_conCallbackSet(struct xbee_con *con, xbee_t_conCallback newCallback, xbee_t_conCallback *oldCallback) {
	if (!con) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	if (oldCallback) *oldCallback = con->callback;
	con->callback = newCallback;
	return xbee_conCallbackProd(con);
}

EXPORT xbee_err xbee_conCallbackGet(struct xbee_con *con, xbee_t_conCallback *curCallback) {
	if (!con || !curCallback) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	*curCallback = con->callback;
	return XBEE_ENONE;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conSettings(struct xbee_con *con, struct xbee_conSettings *newSettings, struct xbee_conSettings *oldSettings) {
	xbee_err ret;
	struct xbee_conSettings tempOld;
	if (!con || (!newSettings && !oldSettings)) return XBEE_EMISSINGPARAM;
#ifndef XBEE_DISABLE_STRICT_OBJECTS
	if (xbee_conValidate(con) != XBEE_ENONE) return XBEE_EINVAL;
#endif /* XBEE_DISABLE_STRICT_OBJECTS */
	
	if (oldSettings) memcpy(&tempOld, &con->settings, sizeof(con->settings));
	
	if (con->xbee->mode->support.conSettings) {
		/* check with support system - this will update the current settings of the con */
		if ((ret = con->xbee->mode->support.conSettings(con, newSettings)) != XBEE_ENONE) return ret;
	}
	
	if (oldSettings) memcpy(oldSettings, &tempOld, sizeof(con->settings));
	if (newSettings) memcpy(&con->settings, newSettings, sizeof(con->settings));
	
	return XBEE_ENONE;
}

/* ########################################################################## */

EXPORT xbee_err xbee_conEnd(struct xbee_con *con) {
	xbee_err ret;
	xbee_err ret2;

	ret = XBEE_ENONE;
	if (con->xbee->mode->support.conEnd) {
		/* check with support system */
		ret = con->xbee->mode->support.conEnd(con);
		if (ret != XBEE_ENONE && ret != XBEE_ESTALE) return ret;
	}
	
	if ((ret2 = xbee_conFree(con)) != XBEE_ENONE) return ret2;
	
	return ret;
}