From e4b1ff461e641f171072dd9e6329fd473d7d6ef0 Mon Sep 17 00:00:00 2001 From: adamdunkels Date: Sat, 14 Feb 2009 20:35:03 +0000 Subject: [PATCH] Added MAC-layer announcement beacons to X-MAC. Configuratble through XMAC_CONF_ANNOUNCEMENTS --- core/net/mac/xmac.c | 190 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 168 insertions(+), 22 deletions(-) diff --git a/core/net/mac/xmac.c b/core/net/mac/xmac.c index 63975596a..fd14a2e22 100644 --- a/core/net/mac/xmac.c +++ b/core/net/mac/xmac.c @@ -28,7 +28,7 @@ * * This file is part of the Contiki operating system. * - * $Id: xmac.c,v 1.22 2009/02/07 18:45:50 adamdunkels Exp $ + * $Id: xmac.c,v 1.23 2009/02/14 20:35:03 adamdunkels Exp $ */ /** @@ -47,7 +47,6 @@ #include "dev/radio.h" #include "dev/watchdog.h" #include "lib/random.h" -/*#include "lib/bb.h"*/ #include "sys/timetable.h" @@ -62,7 +61,31 @@ #define WITH_TIMESYNCH 0 #define WITH_QUEUE 0 +struct announcement_data { + uint16_t id; + uint16_t value; +}; + +/* The maximum number of announcements in a single announcement + message - may need to be increased in the future. */ +#define ANNOUNCEMENT_MAX 10 + +/* The length of the header of the announcement message, i.e., the + "num" field in the struct. */ +#define ANNOUNCEMENT_MSG_HEADERLEN 2 + +/* The structure of the announcement messages. */ +struct announcement_msg { + uint16_t num; + struct announcement_data data[ANNOUNCEMENT_MAX]; +}; + +#define TYPE_STROBE 0 +#define TYPE_DATA 1 +#define TYPE_ANNOUNCEMENT 2 + struct xmac_hdr { + uint16_t type; rimeaddr_t sender; rimeaddr_t receiver; }; @@ -79,6 +102,13 @@ struct xmac_hdr { #define DEFAULT_OFF_TIME (RTIMER_ARCH_SECOND / 2 - DEFAULT_ON_TIME) #endif +/* The cycle time for announcements. */ +#define ANNOUNCEMENT_PERIOD 4 * CLOCK_SECOND + +/* The time before sending an announcement within one announcement + cycle. */ +#define ANNOUNCEMENT_TIME (rand() % (ANNOUNCEMENT_PERIOD)) + #define DEFAULT_STROBE_WAIT_TIME (7 * DEFAULT_ON_TIME / 8) struct xmac_config xmac_config = { @@ -129,6 +159,15 @@ static const struct radio_driver *radio; #define PRINTF(...) #endif +#if XMAC_CONF_ANNOUNCEMENTS +/* Timers for keeping track of when to send announcements. */ +static struct ctimer announcement_cycle_ctimer, announcement_ctimer; +#endif /* XMAC_CONF_ANNOUNCEMENTS */ + +/* Flag that is used to keep track of whether or not we are listening + for announcements from neighbors. */ +static uint8_t is_listening; + static void (* receiver_callback)(const struct mac_driver *); #if WITH_TIMETABLE @@ -159,7 +198,7 @@ on(void) static void off(void) { - if(xmac_is_on && radio_is_on != 0) { + if(xmac_is_on && radio_is_on != 0 && is_listening == 0) { radio_is_on = 0; radio->off(); #if WITH_TIMETABLE @@ -250,6 +289,54 @@ powercycle(struct rtimer *t, void *ptr) PT_END(&pt); } /*---------------------------------------------------------------------------*/ +#if XMAC_CONF_ANNOUNCEMENTS +static int +parse_announcements(rimeaddr_t *from) +{ + /* Parse incoming announcements */ + struct announcement_msg *adata = rimebuf_dataptr(); + int i; + + PRINTF("%d.%d: probe from %d.%d with %d announcements\n", + rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1], + hdr->sender.u8[0], hdr->sender.u8[1], adata->num); + + for(i = 0; i < adata->num; ++i) { + PRINTF("%d.%d: announcement %d: %d\n", + rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1], + adata->data[i].id, + adata->data[i].value); + + announcement_heard(from, + adata->data[i].id, + adata->data[i].value); + } + return i; +} +/*---------------------------------------------------------------------------*/ +static int +format_announcement(char *hdr) +{ + struct announcement_msg *adata; + struct announcement *a; + + /* Construct the announcements */ + adata = (struct announcement_msg *)hdr; + + adata->num = 0; + for(a = announcement_list(); + a != NULL && adata->num < ANNOUNCEMENT_MAX; + a = a->next) { + adata->data[adata->num].id = a->id; + adata->data[adata->num].value = a->value; + adata->num++; + } + + return ANNOUNCEMENT_MSG_HEADERLEN + + sizeof(struct announcement_data) * adata->num; +} +#endif /* XMAC_CONF_ANNOUNCEMENTS */ +/*---------------------------------------------------------------------------*/ static int send_packet(void) { @@ -258,7 +345,10 @@ send_packet(void) int strobes; struct xmac_hdr *hdr; int got_ack = 0; - struct xmac_hdr msg; + struct { + struct xmac_hdr hdr; + struct announcement_msg announcement; + } strobe; int len; int is_broadcast = 0; @@ -272,7 +362,7 @@ send_packet(void) on(); t0 = RTIMER_NOW(); while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + xmac_config.strobe_wait_time * 2)) { - len = radio->read(&msg, sizeof(msg)); + len = radio->read(&strobe.hdr, sizeof(strobe.hdr)); if(len > 0) { someone_is_sending = 1; } @@ -296,6 +386,7 @@ send_packet(void) rimebuf_hdralloc(sizeof(struct xmac_hdr)); hdr = rimebuf_hdrptr(); + hdr->type = TYPE_DATA; rimeaddr_copy(&hdr->sender, &rimeaddr_node_addr); rimeaddr_copy(&hdr->receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER)); if(rimeaddr_cmp(&hdr->receiver, &rimeaddr_null)) { @@ -325,35 +416,30 @@ send_packet(void) strobes++) { t = RTIMER_NOW(); - - rimeaddr_copy(&msg.sender, &rimeaddr_node_addr); - rimeaddr_copy(&msg.receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER)); + strobe.hdr.type = TYPE_STROBE; + rimeaddr_copy(&strobe.hdr.sender, &rimeaddr_node_addr); + rimeaddr_copy(&strobe.hdr.receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER)); #if WITH_TIMETABLE - if(rimeaddr_cmp(&msg.receiver, &rimeaddr_null)) { + if(rimeaddr_cmp(&strobe.hdr.receiver, &rimeaddr_null)) { TIMETABLE_TIMESTAMP(xmac_timetable, "send broadcast strobe"); } else { TIMETABLE_TIMESTAMP(xmac_timetable, "send strobe"); } #endif - if(0/*is_broadcast*/) { - /* If we are sending a broadcast, we don't send strobes, we - simply send the data packet repetedly */ - radio->send(rimebuf_hdrptr(), rimebuf_totlen()); - } else { - /* Send the strobe packet. */ - radio->send((const uint8_t *)&msg, sizeof(struct xmac_hdr)); - } + /* Send the strobe packet. */ + radio->send((const uint8_t *)&strobe, sizeof(struct xmac_hdr)); + CPRINTF("+"); while(got_ack == 0 && RTIMER_CLOCK_LT(RTIMER_NOW(), t + xmac_config.strobe_wait_time)) { /* See if we got an ACK */ - len = radio->read((uint8_t *)&msg, sizeof(struct xmac_hdr)); + len = radio->read((uint8_t *)&strobe, sizeof(struct xmac_hdr)); if(len > 0) { CPRINTF("_"); - if(rimeaddr_cmp(&msg.sender, &rimeaddr_node_addr) && - rimeaddr_cmp(&msg.receiver, &rimeaddr_node_addr)) { + if(rimeaddr_cmp(&strobe.hdr.sender, &rimeaddr_node_addr) && + rimeaddr_cmp(&strobe.hdr.receiver, &rimeaddr_node_addr)) { #if WITH_TIMETABLE TIMETABLE_TIMESTAMP(xmac_timetable, "send ack received"); #endif @@ -469,7 +555,7 @@ read_packet(void) rimebuf_hdrreduce(sizeof(struct xmac_hdr)); - if(rimebuf_totlen() == 0) { + if(hdr->type == TYPE_STROBE) { CPRINTF("."); /* There is no data in the packet so it has to be a strobe. */ someone_is_sending = 2; @@ -510,10 +596,15 @@ read_packet(void) waiting_for_packet = 1; on(); } + + /* Check for annoucements in the strobe */ + /* if(rimebuf_datalen() > 0) { + parse_announcements(&hdr->sender); + }*/ /* We are done processing the strobe and we therefore return to the caller. */ return RIME_OK; - } else { + } else if(hdr->type == TYPE_DATA) { CPRINTF("-"); someone_is_sending = 0; if(rimeaddr_cmp(&hdr->receiver, &rimeaddr_node_addr) || @@ -537,11 +628,60 @@ read_packet(void) return rimebuf_totlen(); } +#if XMAC_CONF_ANNOUNCEMENTS + } else if(hdr->type == TYPE_ANNOUNCEMENT) { + parse_announcements(&hdr->sender); +#endif /* XMAC_CONF_ANNOUNCEMENTS */ } } return 0; } /*---------------------------------------------------------------------------*/ +#if XMAC_CONF_ANNOUNCEMENTS +static void +send_announcement(void *ptr) +{ + struct xmac_hdr *hdr; + struct announcement_msg *adata; + struct announcement *a; + int announcement_len; + + /* Set up the probe header. */ + rimebuf_clear(); + rimebuf_set_datalen(sizeof(struct xmac_hdr)); + hdr = rimebuf_dataptr(); + hdr->type = TYPE_ANNOUNCEMENT; + rimeaddr_copy(&hdr->sender, &rimeaddr_node_addr); + rimeaddr_copy(&hdr->receiver, &rimeaddr_null); + + announcement_len = format_announcement((char *)hdr + + sizeof(struct xmac_hdr)); + + rimebuf_set_datalen(sizeof(struct xmac_hdr) + announcement_len); + + /* PRINTF("Sending probe\n");*/ + radio->send(rimebuf_hdrptr(), rimebuf_totlen()); +} +/*---------------------------------------------------------------------------*/ +static void +cycle_announcement(void *ptr) +{ + ctimer_set(&announcement_ctimer, ANNOUNCEMENT_TIME, + send_announcement, NULL); + ctimer_set(&announcement_cycle_ctimer, ANNOUNCEMENT_PERIOD, + cycle_announcement, NULL); + if(is_listening > 0) { + is_listening--; + } +} +/*---------------------------------------------------------------------------*/ +static void +listen_callback(int periods) +{ + is_listening = periods + 1; +} +#endif /* XMAC_CONF_ANNOUNCEMENTS */ +/*---------------------------------------------------------------------------*/ const struct mac_driver * xmac_init(const struct radio_driver *d) { @@ -563,6 +703,12 @@ xmac_init(const struct radio_driver *d) BB_SET(XMAC_STROBES, 0); BB_SET(XMAC_SEND_WITH_ACK, 0); BB_SET(XMAC_SEND_WITH_NOACK, 0); + +#if XMAC_CONF_ANNOUNCEMENTS + announcement_register_listen_callback(listen_callback); + ctimer_set(&announcement_cycle_ctimer, ANNOUNCEMENT_TIME, + cycle_announcement, NULL); +#endif /* XMAC_CONF_ANNOUNCEMENTS */ return &xmac_driver; } /*---------------------------------------------------------------------------*/