source: libfaim/txqueue.c @ 03ad7b2

/*
 *  aim_txqueue.c
 *
 * Herein lies all the mangement routines for the transmit (Tx) queue.
 *
 */

#define FAIM_INTERNAL
#include <aim.h>

#ifndef _WIN32
#include <sys/socket.h>
#endif

/*
 * Allocate a new tx frame.
 *
 * This is more for looks than anything else.
 *
 * Right now, that is.  If/when we implement a pool of transmit
 * frames, this will become the request-an-unused-frame part.
 *
 * framing = AIM_FRAMETYPE_OFT/FLAP
 * chan = channel for FLAP, hdrtype for OFT
 *
 */
faim_internal aim_frame_t *aim_tx_new(aim_session_t *sess, aim_conn_t *conn, fu8_t framing, fu8_t chan, int datalen)
{
        aim_frame_t *fr;

        if (!conn) {
                faimdprintf(sess, 0, "aim_tx_new: ERROR: no connection specified\n");
                return NULL;
        }

        /* For sanity... */
        if ((conn->type == AIM_CONN_TYPE_RENDEZVOUS) || 
                        (conn->type == AIM_CONN_TYPE_RENDEZVOUS_OUT)) {
                if (framing != AIM_FRAMETYPE_OFT) {
                        faimdprintf(sess, 0, "aim_tx_new: attempted to allocate inappropriate frame type for rendezvous connection\n");
                        return NULL;
                }
        } else {
                if (framing != AIM_FRAMETYPE_FLAP) {
                        faimdprintf(sess, 0, "aim_tx_new: attempted to allocate inappropriate frame type for FLAP connection\n");
                        return NULL;
                }
        }

        if (!(fr = (aim_frame_t *)malloc(sizeof(aim_frame_t))))
                return NULL;
        memset(fr, 0, sizeof(aim_frame_t));

        fr->conn = conn; 

        fr->hdrtype = framing;

        if (fr->hdrtype == AIM_FRAMETYPE_FLAP) {

                fr->hdr.flap.type = chan;

        } else if (fr->hdrtype == AIM_FRAMETYPE_OFT) {

                fr->hdr.oft.type = chan;
                fr->hdr.oft.hdr2len = 0; /* this will get setup by caller */

        } else 
                faimdprintf(sess, 0, "tx_new: unknown framing\n");

        if (datalen > 0) {
                fu8_t *data;

                if (!(data = (unsigned char *)malloc(datalen))) {
                        aim_frame_destroy(fr);
                        return NULL;
                }

                aim_bstream_init(&fr->data, data, datalen);
        }

        return fr;
}

/*
 * aim_tx_enqeue__queuebased()
 *
 * The overall purpose here is to enqueue the passed in command struct
 * into the outgoing (tx) queue.  Basically...
 *   1) Make a scope-irrelevent copy of the struct
 *   3) Mark as not-sent-yet
 *   4) Enqueue the struct into the list
 *   6) Return
 *
 * Note that this is only used when doing queue-based transmitting;
 * that is, when sess->tx_enqueue is set to &aim_tx_enqueue__queuebased.
 *
 */
static int aim_tx_enqueue__queuebased(aim_session_t *sess, aim_frame_t *fr)
{

        if (!fr->conn) {
                faimdprintf(sess, 1, "aim_tx_enqueue: WARNING: enqueueing packet with no connecetion\n");
                fr->conn = aim_getconn_type(sess, AIM_CONN_TYPE_BOS);
        }

        if (fr->hdrtype == AIM_FRAMETYPE_FLAP) {
                /* assign seqnum -- XXX should really not assign until hardxmit */
                fr->hdr.flap.seqnum = aim_get_next_txseqnum(fr->conn);
        }

        fr->handled = 0; /* not sent yet */

        /* see overhead note in aim_rxqueue counterpart */
        if (!sess->queue_outgoing)
                sess->queue_outgoing = fr;
        else {
                aim_frame_t *cur;

                for (cur = sess->queue_outgoing; cur->next; cur = cur->next)
                        ;
                cur->next = fr;
        }

        return 0;
}

/*
 * aim_tx_enqueue__immediate()
 *
 * Parallel to aim_tx_enqueue__queuebased, however, this bypasses
 * the whole queue mess when you want immediate writes to happen.
 *
 * Basically the same as its __queuebased couterpart, however
 * instead of doing a list append, it just calls aim_tx_sendframe()
 * right here. 
 * 
 */
static int aim_tx_enqueue__immediate(aim_session_t *sess, aim_frame_t *fr)
{

        if (!fr->conn) {
                faimdprintf(sess, 1, "aim_tx_enqueue: ERROR: packet has no connection\n");
                aim_frame_destroy(fr);
                return 0;
        }

        if (fr->hdrtype == AIM_FRAMETYPE_FLAP)
                fr->hdr.flap.seqnum = aim_get_next_txseqnum(fr->conn);

        fr->handled = 0; /* not sent yet */

        aim_tx_sendframe(sess, fr);

        aim_frame_destroy(fr);

        return 0;
}

faim_export int aim_tx_setenqueue(aim_session_t *sess, int what, int (*func)(aim_session_t *, aim_frame_t *))
{
        
        if (what == AIM_TX_QUEUED)
                sess->tx_enqueue = &aim_tx_enqueue__queuebased;
        else if (what == AIM_TX_IMMEDIATE) 
                sess->tx_enqueue = &aim_tx_enqueue__immediate;
        else if (what == AIM_TX_USER) {
                if (!func)
                        return -EINVAL;
                sess->tx_enqueue = func;
        } else
                return -EINVAL; /* unknown action */

        return 0;
}

faim_internal int aim_tx_enqueue(aim_session_t *sess, aim_frame_t *fr)
{
        
        /*
         * If we want to send a connection thats inprogress, we have to force
         * them to use the queue based version. Otherwise, use whatever they
         * want.
         */
        if (fr && fr->conn && 
                        (fr->conn->status & AIM_CONN_STATUS_INPROGRESS)) {
                return aim_tx_enqueue__queuebased(sess, fr);
        }

        return (*sess->tx_enqueue)(sess, fr);
}

/* 
 *  aim_get_next_txseqnum()
 *
 *   This increments the tx command count, and returns the seqnum
 *   that should be stamped on the next FLAP packet sent.  This is
 *   normally called during the final step of packet preparation
 *   before enqueuement (in aim_tx_enqueue()).
 *
 */
faim_internal flap_seqnum_t aim_get_next_txseqnum(aim_conn_t *conn)
{
        flap_seqnum_t ret;
        
        ret = ++conn->seqnum;

        return ret;
}

static int aim_send(int fd, const void *buf, size_t count)
{
        int left, cur;

        for (cur = 0, left = count; left; ) {
                int ret;

                ret = send(fd, ((unsigned char *)buf)+cur, left, 0);
                if (ret == -1)
                        return -1;
                else if (ret == 0)
                        return cur;

                cur += ret;
                left -= ret;
        }

        return cur;
}

static int aim_bstream_send(aim_bstream_t *bs, aim_conn_t *conn, size_t count)
{
        int wrote = 0;

        if (!bs || !conn || (count < 0))
                return -EINVAL;

        if (count > aim_bstream_empty(bs))
                count = aim_bstream_empty(bs); /* truncate to remaining space */

        if (count)
                wrote = aim_send(conn->fd, bs->data + bs->offset, count);

        if (((aim_session_t *)conn->sessv)->debug >= 2) {
                int i;
                aim_session_t *sess = (aim_session_t *)conn->sessv;

                faimdprintf(sess, 2, "\nOutgoing data: (%d bytes)", wrote);
                for (i = 0; i < wrote; i++) {
                        if (!(i % 8)) 
                                faimdprintf(sess, 2, "\n\t");
                        faimdprintf(sess, 2, "0x%02x ", *(bs->data + bs->offset + i));
                }
                faimdprintf(sess, 2, "\n");
        }


        bs->offset += wrote;

        return wrote;   
}

static int sendframe_flap(aim_session_t *sess, aim_frame_t *fr)
{
        aim_bstream_t obs;
        fu8_t *obs_raw;
        int payloadlen, err = 0, obslen;

        payloadlen = aim_bstream_curpos(&fr->data);

        if (!(obs_raw = malloc(6 + payloadlen)))
                return -ENOMEM;

        aim_bstream_init(&obs, obs_raw, 6 + payloadlen);

        /* FLAP header */
        aimbs_put8(&obs, 0x2a);
        aimbs_put8(&obs, fr->hdr.flap.type);
        aimbs_put16(&obs, fr->hdr.flap.seqnum);
        aimbs_put16(&obs, payloadlen);

        /* payload */
        aim_bstream_rewind(&fr->data);
        aimbs_putbs(&obs, &fr->data, payloadlen);

        obslen = aim_bstream_curpos(&obs);
        aim_bstream_rewind(&obs);

        if (aim_bstream_send(&obs, fr->conn, obslen) != obslen)
                err = -errno;
        
        free(obs_raw); /* XXX aim_bstream_free */

        fr->handled = 1;
        fr->conn->lastactivity = time(NULL);

        return err;
}

static int sendframe_oft(aim_session_t *sess, aim_frame_t *fr)
{
        aim_bstream_t hbs;
        fu8_t *hbs_raw;
        int hbslen;
        int err = 0;

        hbslen = 8 + fr->hdr.oft.hdr2len;

        if (!(hbs_raw = malloc(hbslen)))
                return -1;

        aim_bstream_init(&hbs, hbs_raw, hbslen);

        aimbs_putraw(&hbs, fr->hdr.oft.magic, 4);
        aimbs_put16(&hbs, fr->hdr.oft.hdr2len + 8);
        aimbs_put16(&hbs, fr->hdr.oft.type);
        aimbs_putraw(&hbs, fr->hdr.oft.hdr2, fr->hdr.oft.hdr2len);

        aim_bstream_rewind(&hbs);
        
        if (aim_bstream_send(&hbs, fr->conn, hbslen) != hbslen) {

                err = -errno;
                
        } else if (aim_bstream_curpos(&fr->data)) {
                int len;

                len = aim_bstream_curpos(&fr->data);
                aim_bstream_rewind(&fr->data);
                
                if (aim_bstream_send(&fr->data, fr->conn, len) != len)
                        err = -errno;
        }

        free(hbs_raw); /* XXX aim_bstream_free */

        fr->handled = 1;
        fr->conn->lastactivity = time(NULL);


        return err;
}

faim_internal int aim_tx_sendframe(aim_session_t *sess, aim_frame_t *fr)
{
        if (fr->hdrtype == AIM_FRAMETYPE_FLAP)
                return sendframe_flap(sess, fr);
        else if (fr->hdrtype == AIM_FRAMETYPE_OFT)
                return sendframe_oft(sess, fr);
        return -1;
}

faim_export int aim_tx_flushqueue(aim_session_t *sess)
{
        aim_frame_t *cur;

        for (cur = sess->queue_outgoing; cur; cur = cur->next) {

                if (cur->handled)
                        continue; /* already been sent */

                if (cur->conn && (cur->conn->status & AIM_CONN_STATUS_INPROGRESS))
                        continue;

                /*
                 * And now for the meager attempt to force transmit
                 * latency and avoid missed messages.
                 */
                if ((cur->conn->lastactivity + cur->conn->forcedlatency) >= time(NULL)) {
                        /* 
                         * XXX should be a break! we dont want to block the 
                         * upper layers
                         *
                         * XXX or better, just do this right.
                         *
                         */
                        sleep((cur->conn->lastactivity + cur->conn->forcedlatency) - time(NULL));
                }

                /* XXX this should call the custom "queuing" function!! */
                aim_tx_sendframe(sess, cur);
        }

        /* purge sent commands from queue */
        aim_tx_purgequeue(sess);

        return 0;
}

/*
 *  aim_tx_purgequeue()
 *  
 *  This is responsable for removing sent commands from the transmit 
 *  queue. This is not a required operation, but it of course helps
 *  reduce memory footprint at run time!  
 *
 */
faim_export void aim_tx_purgequeue(aim_session_t *sess)
{
        aim_frame_t *cur, **prev;

        for (prev = &sess->queue_outgoing; (cur = *prev); ) {

                if (cur->handled) {
                        *prev = cur->next;

                        aim_frame_destroy(cur);

                } else
                        prev = &cur->next;
        }

        return;
}

/**
 * aim_tx_cleanqueue - get rid of packets waiting for tx on a dying conn
 * @sess: session
 * @conn: connection that's dying
 *
 * for now this simply marks all packets as sent and lets them
 * disappear without warning.
 *
 */
faim_export void aim_tx_cleanqueue(aim_session_t *sess, aim_conn_t *conn)
{
        aim_frame_t *cur;

        for (cur = sess->queue_outgoing; cur; cur = cur->next) {
                if (cur->conn == conn)
                        cur->handled = 1;
        }

        return;
}