udp_usrreq.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

	struct mbuf *addr, *control;
{
	register struct udpiphdr *ui;
	register int len = m->m_pkthdr.len;
	struct in_addr laddr;
	int s = 0, error = 0;

	if (control)
		m_freem(control);		/* XXX */

	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
		error = EMSGSIZE;
		goto release;
	}

	if (addr) {
		laddr = inp->inp_laddr;
		if (inp->inp_faddr.s_addr != INADDR_ANY) {
			error = EISCONN;
			goto release;
		}
		/*
		 * Must block input while temporarily connected.
		 */
		s = splnet();
		error = in_pcbconnect(inp, addr);
		if (error) {
			splx(s);
			goto release;
		}
	} else {
		if (inp->inp_faddr.s_addr == INADDR_ANY) {
			error = ENOTCONN;
			goto release;
		}
	}
	/*
	 * Calculate data length and get a mbuf
	 * for UDP and IP headers.
	 */
	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
	if (m == 0) {
		error = ENOBUFS;
		if (addr)
			splx(s);
		goto release;
	}

	/*
	 * Fill in mbuf with extended UDP header
	 * and addresses and length put into network format.
	 */
	ui = mtod(m, struct udpiphdr *);
	ui->ui_next = ui->ui_prev = 0;
	ui->ui_x1 = 0;
	ui->ui_pr = IPPROTO_UDP;
	ui->ui_len = htons((u_short)len + sizeof (struct udphdr));
	ui->ui_src = inp->inp_laddr;
	ui->ui_dst = inp->inp_faddr;
	ui->ui_sport = inp->inp_lport;
	ui->ui_dport = inp->inp_fport;
	ui->ui_ulen = ui->ui_len;

	/*
	 * Stuff checksum and output datagram.
	 */
	ui->ui_sum = 0;
	if (udpcksum) {
	    if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0)
		ui->ui_sum = 0xffff;
	}
	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
	((struct ip *)ui)->ip_tos = inp->inp_ip_tos;	/* XXX */
	udpstat.udps_opackets++;
	error = ip_output(m, inp->inp_options, &inp->inp_route,
	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST),
	    inp->inp_moptions);

	if (addr) {
		in_pcbdisconnect(inp);
		inp->inp_laddr = laddr;
		splx(s);
	}
	return (error);

release:
	m_freem(m);
	return (error);
}

#ifdef __rtems__
#define INP_INFO_RLOCK(a)
#define INP_INFO_RUNLOCK(a)
#define INP_LOCK(a)
#define INP_UNLOCK(a)
#endif

static int
udp_pcblist(SYSCTL_HANDLER_ARGS)
{
	int error, i, n, s;
	struct inpcb *inp, **inp_list;
	inp_gen_t gencnt;
	struct xinpgen xig;

	/*
	 * The process of preparing the TCB list is too time-consuming and
	 * resource-intensive to repeat twice on every request.
	 */
	if (req->oldptr == 0) {
		n = udbinfo.ipi_count;
		req->oldidx = 2 * (sizeof xig)
			+ (n + n/8) * sizeof(struct xinpcb);
		return 0;
	}

	if (req->newptr != 0)
		return EPERM;

	/*
	 * OK, now we're committed to doing something.
	 */
	s = splnet();
	gencnt = udbinfo.ipi_gencnt;
	n = udbinfo.ipi_count;
	splx(s);

	sysctl_wire_old_buffer(req, 2 * (sizeof xig)
		+ n * sizeof(struct xinpcb));

	xig.xig_len = sizeof xig;
	xig.xig_count = n;
	xig.xig_gen = gencnt;
#if 0
	xig.xig_sogen = so_gencnt;
#endif
	error = SYSCTL_OUT(req, &xig, sizeof xig);
	if (error)
		return error;

  /* ccj add the exit if count is 0 */
  if (!n)
    return error;
  
	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
	if (inp_list == 0)
		return ENOMEM;
	
	s = splnet();
	INP_INFO_RLOCK(&udbinfo);
	for (inp = LIST_FIRST(udbinfo.listhead), i = 0; inp && i < n;
	     inp = LIST_NEXT(inp, inp_list)) {
		INP_LOCK(inp);
		if (inp->inp_gencnt <= gencnt)
#if 0
      &&
		    cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
#endif
			inp_list[i++] = inp;
		INP_UNLOCK(inp);
	}
	INP_INFO_RUNLOCK(&udbinfo);
	splx(s);
	n = i;

	error = 0;
	for (i = 0; i < n; i++) {
		inp = inp_list[i];
		INP_LOCK(inp);
		if (inp->inp_gencnt <= gencnt) {
			struct xinpcb xi;
			xi.xi_len = sizeof xi;
			/* XXX should avoid extra copy */
			bcopy(inp, &xi.xi_inp, sizeof *inp);
#if 0
			if (inp->inp_socket)
				sotoxsocket(inp->inp_socket, &xi.xi_socket);
#endif
			error = SYSCTL_OUT(req, &xi, sizeof xi);
		}
		INP_UNLOCK(inp);
	}
	if (!error) {
		/*
		 * Give the user an updated idea of our state.
		 * If the generation differs from what we told
		 * her before, she knows that something happened
		 * while we were processing this request, and it
		 * might be necessary to retry.
		 */
		s = splnet();
		INP_INFO_RLOCK(&udbinfo);
		xig.xig_gen = udbinfo.ipi_gencnt;
#if 0
		xig.xig_sogen = so_gencnt;
#endif
		xig.xig_count = udbinfo.ipi_count;
		INP_INFO_RUNLOCK(&udbinfo);
		splx(s);
		error = SYSCTL_OUT(req, &xig, sizeof xig);
	}
	free(inp_list, M_TEMP);
	return error;
}

SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
	    udp_pcblist, "S,xinpcb", "List of active UDP sockets");

static u_long	udp_sendspace = 9216;		/* really max datagram size */
					/* 40 1K datagrams */
SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
	&udp_sendspace, 0, "");

static u_long	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
	&udp_recvspace, 0, "");

/*ARGSUSED*/
int
udp_usrreq(so, req, m, addr, control)
	struct socket *so;
	int req;
	struct mbuf *m, *addr, *control;
{
	struct inpcb *inp = sotoinpcb(so);
	int error = 0;
	int s;

	if (req == PRU_CONTROL)
		return (in_control(so, (u_long)m, (caddr_t)addr,
			(struct ifnet *)control));
	if (inp == NULL && req != PRU_ATTACH) {
		error = EINVAL;
		goto release;
	}
	/*
	 * Note: need to block udp_input while changing
	 * the udp pcb queue and/or pcb addresses.
	 */
	switch (req) {

	case PRU_ATTACH:
		if (inp != NULL) {
			error = EINVAL;
			break;
		}
		s = splnet();
		error = in_pcballoc(so, &udbinfo);
		splx(s);
		if (error)
			break;
		error = soreserve(so, udp_sendspace, udp_recvspace);
		if (error)
			break;
		((struct inpcb *) so->so_pcb)->inp_ip_ttl = ip_defttl;
		break;

	case PRU_DETACH:
		udp_detach(inp);
		break;

	case PRU_BIND:
		s = splnet();
		error = in_pcbbind(inp, addr);
		splx(s);
		break;

	case PRU_LISTEN:
		error = EOPNOTSUPP;
		break;

	case PRU_CONNECT:
		if (inp->inp_faddr.s_addr != INADDR_ANY) {
			error = EISCONN;
			break;
		}
		s = splnet();
		error = in_pcbconnect(inp, addr);
		splx(s);
		if (error == 0)
			soisconnected(so);
		break;

	case PRU_CONNECT2:
		error = EOPNOTSUPP;
		break;

	case PRU_ACCEPT:
		error = EOPNOTSUPP;
		break;

	case PRU_DISCONNECT:
		if (inp->inp_faddr.s_addr == INADDR_ANY) {
			error = ENOTCONN;
			break;
		}
		s = splnet();
		in_pcbdisconnect(inp);
		inp->inp_laddr.s_addr = INADDR_ANY;
		splx(s);
		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
		break;

	case PRU_SHUTDOWN:
		socantsendmore(so);
		break;

	case PRU_SEND:
		return (udp_output(inp, m, addr, control));

	case PRU_ABORT:
		soisdisconnected(so);
		udp_detach(inp);
		break;

	case PRU_SOCKADDR:
		in_setsockaddr(inp, addr);
		break;

	case PRU_PEERADDR:
		in_setpeeraddr(inp, addr);
		break;

	case PRU_SENSE:
		/*
		 * stat: don't bother with a blocksize.
		 */
		return (0);

	case PRU_SENDOOB:
	case PRU_FASTTIMO:
	case PRU_SLOWTIMO:
	case PRU_PROTORCV:
	case PRU_PROTOSEND:
		error =  EOPNOTSUPP;
		break;

	case PRU_RCVD:
	case PRU_RCVOOB:
		return (EOPNOTSUPP);	/* do not free mbuf's */

	default:
		panic("udp_usrreq");
	}

release:
	if (control) {
		printf("udp control data unexpectedly retained\n");
		m_freem(control);
	}
	if (m)
		m_freem(m);
	return (error);
}

static void
udp_detach(inp)
	struct inpcb *inp;
{
	int s = splnet();

	in_pcbdetach(inp);
	splx(s);
}