sockets.c

Android 一些工具

*/
typedef struct aremotesocket {
    asocket      socket;
    adisconnect  disconnect;
} aremotesocket;

static int remote_socket_enqueue(asocket *s, apacket *p)
{
    D("Calling remote_socket_enqueue\n");
    p->msg.command = A_WRTE;
    p->msg.arg0 = s->peer->id;
    p->msg.arg1 = s->id;
    p->msg.data_length = p->len;
    send_packet(p, s->transport);
    return 1;
}

static void remote_socket_ready(asocket *s)
{
    D("Calling remote_socket_ready\n");
    apacket *p = get_apacket();
    p->msg.command = A_OKAY;
    p->msg.arg0 = s->peer->id;
    p->msg.arg1 = s->id;
    send_packet(p, s->transport);
}

static void remote_socket_close(asocket *s)
{
    D("Calling remote_socket_close\n");
    apacket *p = get_apacket();
    p->msg.command = A_CLSE;
    if(s->peer) {
        p->msg.arg0 = s->peer->id;
        s->peer->peer = 0;
        s->peer->close(s->peer);
    }
    p->msg.arg1 = s->id;
    send_packet(p, s->transport);
    D("RS(%d): closed\n", s->id);
    remove_transport_disconnect( s->transport, &((aremotesocket*)s)->disconnect );
    free(s);
}

static void remote_socket_disconnect(void*  _s, atransport*  t)
{
    asocket*  s    = _s;
    asocket*  peer = s->peer;

    D("remote_socket_disconnect RS(%d)\n", s->id);
    if (peer) {
        peer->peer = NULL;
        peer->close(peer);
    }
    remove_transport_disconnect( s->transport, &((aremotesocket*)s)->disconnect );
    free(s);
}

asocket *create_remote_socket(unsigned id, atransport *t)
{
    asocket *s = calloc(1, sizeof(aremotesocket));
    adisconnect*  dis = &((aremotesocket*)s)->disconnect;

    if(s == 0) fatal("cannot allocate socket");
    s->id = id;
    s->enqueue = remote_socket_enqueue;
    s->ready = remote_socket_ready;
    s->close = remote_socket_close;
    s->transport = t;

    dis->func   = remote_socket_disconnect;
    dis->opaque = s;
    add_transport_disconnect( t, dis );
    D("RS(%d): created\n", s->id);
    return s;
}

void connect_to_remote(asocket *s, const char *destination)
{
    D("Connect_to_remote call \n");
    apacket *p = get_apacket();
    int len = strlen(destination) + 1;

    if(len > (MAX_PAYLOAD-1)) {
        fatal("destination oversized");
    }

    D("LS(%d): connect('%s')\n", s->id, destination);
    p->msg.command = A_OPEN;
    p->msg.arg0 = s->id;
    p->msg.data_length = len;
    strcpy((char*) p->data, destination);
    send_packet(p, s->transport);
}


/* this is used by magic sockets to rig local sockets to
   send the go-ahead message when they connect */
static void local_socket_ready_notify(asocket *s)
{
    s->ready = local_socket_ready;
    s->close = local_socket_close;
    adb_write(s->fd, "OKAY", 4);
    s->ready(s);
}

/* this is used by magic sockets to rig local sockets to
   send the failure message if they are closed before
   connected (to avoid closing them without a status message) */
static void local_socket_close_notify(asocket *s)
{
    s->ready = local_socket_ready;
    s->close = local_socket_close;
    sendfailmsg(s->fd, "closed");
    s->close(s);
}

unsigned unhex(unsigned char *s, int len)
{
    unsigned n = 0, c;

    while(len-- > 0) {
        switch((c = *s++)) {
        case '0': case '1': case '2':
        case '3': case '4': case '5':
        case '6': case '7': case '8':
        case '9':
            c -= '0';
            break;
        case 'a': case 'b': case 'c':
        case 'd': case 'e': case 'f':
            c = c - 'a' + 10;
            break;
        case 'A': case 'B': case 'C':
        case 'D': case 'E': case 'F':
            c = c - 'A' + 10;
            break;
        default:
            return 0xffffffff;
        }

        n = (n << 4) | c;
    }

    return n;
}

static int smart_socket_enqueue(asocket *s, apacket *p)
{
    unsigned len;
#if ADB_HOST
    char *service = NULL;
    char* serial = NULL;
    transport_type ttype = kTransportAny;
#endif

    D("SS(%d): enqueue %d\n", s->id, p->len);

    if(s->pkt_first == 0) {
        s->pkt_first = p;
        s->pkt_last = p;
    } else {
        if((s->pkt_first->len + p->len) > MAX_PAYLOAD) {
            D("SS(%d): overflow\n", s->id);
            put_apacket(p);
            goto fail;
        }

        memcpy(s->pkt_first->data + s->pkt_first->len,
               p->data, p->len);
        s->pkt_first->len += p->len;
        put_apacket(p);

        p = s->pkt_first;
    }

        /* don't bother if we can't decode the length */
    if(p->len < 4) return 0;

    len = unhex(p->data, 4);
    if((len < 1) ||  (len > 1024)) {
        D("SS(%d): bad size (%d)\n", s->id, len);
        goto fail;
    }

    D("SS(%d): len is %d\n", s->id, len );
        /* can't do anything until we have the full header */
    if((len + 4) > p->len) {
        D("SS(%d): waiting for %d more bytes\n", s->id, len+4 - p->len);
        return 0;
    }

    p->data[len + 4] = 0;

    D("SS(%d): '%s'\n", s->id, (char*) (p->data + 4));

#if ADB_HOST
    service = (char *)p->data + 4;
    if(!strncmp(service, "host-serial:", strlen("host-serial:"))) {
        char* serial_end;
        service += strlen("host-serial:");

        // serial number should follow "host:"
        serial_end = strchr(service, ':');
        if (serial_end) {
            *serial_end = 0; // terminate string
            serial = service;
            service = serial_end + 1;
        }
    } else if (!strncmp(service, "host-usb:", strlen("host-usb:"))) {
        ttype = kTransportUsb;
        service += strlen("host-usb:");
    } else if (!strncmp(service, "host-local:", strlen("host-local:"))) {
        ttype = kTransportLocal;
        service += strlen("host-local:");
    } else if (!strncmp(service, "host:", strlen("host:"))) {
        ttype = kTransportAny;
        service += strlen("host:");
    } else {
        service = NULL;
    }

    if (service) {
        asocket *s2;

            /* some requests are handled immediately -- in that
            ** case the handle_host_request() routine has sent
            ** the OKAY or FAIL message and all we have to do
            ** is clean up.
            */
        if(handle_host_request(service, ttype, serial, s->peer->fd, s) == 0) {
                /* XXX fail message? */
            D( "SS(%d): handled host service '%s'\n", s->id, service );
            goto fail;
        }
        if (!strncmp(service, "transport", strlen("transport"))) {
            D( "SS(%d): okay transport\n", s->id );
            p->len = 0;
            return 0;
        }

            /* try to find a local service with this name.
            ** if no such service exists, we'll fail out
            ** and tear down here.
            */
        s2 = create_host_service_socket(service, serial);
        if(s2 == 0) {
            D( "SS(%d): couldn't create host service '%s'\n", s->id, service );
            sendfailmsg(s->peer->fd, "unknown host service");
            goto fail;
        }

            /* we've connected to a local host service,
            ** so we make our peer back into a regular
            ** local socket and bind it to the new local
            ** service socket, acknowledge the successful
            ** connection, and close this smart socket now
            ** that its work is done.
            */
        adb_write(s->peer->fd, "OKAY", 4);

        s->peer->ready = local_socket_ready;
        s->peer->close = local_socket_close;
        s->peer->peer = s2;
        s2->peer = s->peer;
        s->peer = 0;
        D( "SS(%d): okay\n", s->id );
        s->close(s);

            /* initial state is "ready" */
        s2->ready(s2);
        return 0;
    }
#else /* !ADB_HOST */
    if (s->transport == NULL) {
        char* error_string = "unknown failure";
        s->transport = acquire_one_transport (CS_ANY,
                kTransportAny, NULL, &error_string);

        if (s->transport == NULL) {
            sendfailmsg(s->peer->fd, error_string);
            goto fail;
        }
    }
#endif

    if(!(s->transport) || (s->transport->connection_state == CS_OFFLINE)) {
           /* if there's no remote we fail the connection
            ** right here and terminate it
            */
        sendfailmsg(s->peer->fd, "device offline (x)");
        goto fail;
    }


        /* instrument our peer to pass the success or fail
        ** message back once it connects or closes, then
        ** detach from it, request the connection, and
        ** tear down
        */
    s->peer->ready = local_socket_ready_notify;
    s->peer->close = local_socket_close_notify;
    s->peer->peer = 0;
        /* give him our transport and upref it */
    s->peer->transport = s->transport;

    connect_to_remote(s->peer, (char*) (p->data + 4));
    s->peer = 0;
    s->close(s);
    return 1;

fail:
        /* we're going to close our peer as a side-effect, so
        ** return -1 to signal that state to the local socket
        ** who is enqueueing against us
        */
    s->close(s);
    return -1;
}

static void smart_socket_ready(asocket *s)
{
    D("SS(%d): ready\n", s->id);
}

static void smart_socket_close(asocket *s)
{
    D("SS(%d): closed\n", s->id);
    if(s->pkt_first){
        put_apacket(s->pkt_first);
    }
    if(s->peer) {
        s->peer->peer = 0;
        s->peer->close(s->peer);
    }
    free(s);
}

asocket *create_smart_socket(void (*action_cb)(asocket *s, const char *act))
{
    D("Creating smart socket \n");
    asocket *s = calloc(1, sizeof(asocket));
    if(s == 0) fatal("cannot allocate socket");
    s->id = 0;
    s->enqueue = smart_socket_enqueue;
    s->ready = smart_socket_ready;
    s->close = smart_socket_close;
    s->extra = action_cb;

    D("SS(%d): created %p\n", s->id, action_cb);
    return s;
}

void smart_socket_action(asocket *s, const char *act)
{

}

void connect_to_smartsocket(asocket *s)
{
    D("Connecting to smart socket \n");
    asocket *ss = create_smart_socket(smart_socket_action);
    s->peer = ss;
    ss->peer = s;
    s->ready(s);
}