udp_usrreq.c

来自「eCos操作系统源码」· C语言 代码 · 共 932 行 · 第 1/2 页

 * subroutine of udp_input(), mainly for source code readability.
 * caller must properly init udp_ip6 and udp_in6 beforehand.
 */
static void
udp_append(last, ip, n, off)
	struct inpcb *last;
	struct ip *ip;
	struct mbuf *n;
	int off;
{
	struct sockaddr *append_sa;
	struct mbuf *opts = 0;
#ifdef INET6
	struct ip6_recvpktopts opts6;

	bzero(&opts6, sizeof(opts6));
#endif
	if (last->inp_flags & INP_CONTROLOPTS ||
	    last->inp_socket->so_options & SO_TIMESTAMP) {
#ifdef INET6
		if (last->inp_vflag & INP_IPV6) {
			int savedflags;

			if (udp_ip6.uip6_init_done == 0) {
				ip_2_ip6_hdr(&udp_ip6.uip6_ip6, ip);
				udp_ip6.uip6_init_done = 1;
			}
			savedflags = last->inp_flags;
			last->inp_flags &= ~INP_UNMAPPABLEOPTS;
 			ip6_savecontrol(last, &udp_ip6.uip6_ip6, n,
 					&opts6, NULL);
			last->inp_flags = savedflags;
		} else
#endif
		ip_savecontrol(last, &opts, ip, n);
	}
#ifdef INET6
	if (last->inp_vflag & INP_IPV6) {
		if (udp_in6.uin6_init_done == 0) {
			in6_sin_2_v4mapsin6(&udp_in, &udp_in6.uin6_sin);
			udp_in6.uin6_init_done = 1;
		}
		append_sa = (struct sockaddr *)&udp_in6.uin6_sin;
 		opts = opts6.head;
	} else
#endif
	append_sa = (struct sockaddr *)&udp_in;
	m_adj(n, off);
	if (sbappendaddr(&last->inp_socket->so_rcv, append_sa, n, opts) == 0) {
		m_freem(n);
		if (opts)
			m_freem(opts);
		udpstat.udps_fullsock++;
	} else
		sorwakeup(last->inp_socket);
}

/*
 * Notify a udp user of an asynchronous error;
 * just wake up so that he can collect error status.
 */
void
udp_notify(inp, _errno)
	register struct inpcb *inp;
	int _errno;
{
	inp->inp_socket->so_error = _errno;
	sorwakeup(inp->inp_socket);
	sowwakeup(inp->inp_socket);
}

void
udp_ctlinput(cmd, sa, vip)
	int cmd;
	struct sockaddr *sa;
	void *vip;
{
	struct ip *ip = vip;
	struct udphdr *uh;
	void (*notify) __P((struct inpcb *, int)) = udp_notify;
        struct in_addr faddr;
	struct inpcb *inp;
	int s;

	faddr = ((struct sockaddr_in *)sa)->sin_addr;
	if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
        	return;

	if (PRC_IS_REDIRECT(cmd)) {
		ip = 0;
		notify = in_rtchange;
	} else if (cmd == PRC_HOSTDEAD)
		ip = 0;
	else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
		return;
	if (ip) {
		s = splnet();
		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
		inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
                    ip->ip_src, uh->uh_sport, 0, NULL);
		if (inp != NULL && inp->inp_socket != NULL)
			(*notify)(inp, inetctlerrmap[cmd]);
		splx(s);
	} else
		in_pcbnotifyall(&udb, faddr, inetctlerrmap[cmd], notify);
}
#ifdef CYGPKG_NET_FREEBSD_SYSCTL
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);

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

	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
	if (inp_list == 0)
		return ENOMEM;
	
	s = splnet();
	for (inp = LIST_FIRST(udbinfo.listhead), i = 0; inp && i < n;
	     inp = LIST_NEXT(inp, inp_list)) {
		if (inp->inp_gencnt <= gencnt)
			inp_list[i++] = inp;
	}
	splx(s);
	n = i;

	error = 0;
	for (i = 0; i < n; i++) {
		inp = inp_list[i];
		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 (inp->inp_socket)
				sotoxsocket(inp->inp_socket, &xi.xi_socket);
			error = SYSCTL_OUT(req, &xi, sizeof xi);
		}
	}
	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();
		xig.xig_gen = udbinfo.ipi_gencnt;
		xig.xig_sogen = so_gencnt;
		xig.xig_count = udbinfo.ipi_count;
		splx(s);
		error = SYSCTL_OUT(req, &xig, sizeof xig);
	}
	free(inp_list, M_TEMP);
	return error;
}
#endif

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

static int
udp_output(inp, m, addr, control, p)
	register struct inpcb *inp;
	struct mbuf *m;
	struct sockaddr *addr;
	struct mbuf *control;
	struct proc *p;
{
	register struct udpiphdr *ui;
	register int len = m->m_pkthdr.len;
	struct in_addr laddr;
	struct sockaddr_in *sin;
	int s = 0, error = 0;

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

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

	if (addr) {
		sin = (struct sockaddr_in *)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, p);
		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 *);
	bzero(ui->ui_x1, sizeof(ui->ui_x1));	/* XXX still needed? */
	ui->ui_pr = IPPROTO_UDP;
	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 = htons((u_short)len + sizeof(struct udphdr));

	/*
	 * Set up checksum and output datagram.
	 */
	if (udpcksum) {
        	ui->ui_sum = in_pseudo(ui->ui_src.s_addr, ui->ui_dst.s_addr,
		    htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
		m->m_pkthdr.csum_flags = CSUM_UDP;
		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
	} else {
		ui->ui_sum = 0;
	}
	((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++;

#ifdef IPSEC
	if (ipsec_setsocket(m, inp->inp_socket) != 0) {
		error = ENOBUFS;
		goto release;
	}
#endif /*IPSEC*/
	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;	/* XXX rehash? */
		splx(s);
	}
	return (error);

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

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, "Maximum outgoing UDP datagram size");

u_long	udp_recvspace = 40 * (1024 +
#ifdef INET6
				      sizeof(struct sockaddr_in6)
#else
				      sizeof(struct sockaddr_in)
#endif
				      );
SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
    &udp_recvspace, 0, "Maximum incoming UDP datagram size");

static int
udp_abort(struct socket *so)
{
	struct inpcb *inp;
	int s;

	inp = sotoinpcb(so);
	if (inp == 0)
		return EINVAL;	/* ??? possible? panic instead? */
	soisdisconnected(so);
	s = splnet();
	in_pcbdetach(inp);
	splx(s);
	return 0;
}

static int
udp_attach(struct socket *so, int proto, struct proc *p)
{
	struct inpcb *inp;
	int s, error;

	inp = sotoinpcb(so);
	if (inp != 0)
		return EINVAL;

	error = soreserve(so, udp_sendspace, udp_recvspace);
	if (error)
		return error;
	s = splnet();
	error = in_pcballoc(so, &udbinfo, p);
	splx(s);
	if (error)
		return error;

	inp = (struct inpcb *)so->so_pcb;
	inp->inp_vflag |= INP_IPV4;
	inp->inp_ip_ttl = ip_defttl;
	return 0;
}

static int
udp_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
{
	struct inpcb *inp;
	int s, error;

	inp = sotoinpcb(so);
	if (inp == 0)
		return EINVAL;
	s = splnet();
	error = in_pcbbind(inp, nam, p);
	splx(s);
	return error;
}

static int
udp_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
{
	struct inpcb *inp;
	int s, error;
	struct sockaddr_in *sin;

	inp = sotoinpcb(so);
	if (inp == 0)
		return EINVAL;
	if (inp->inp_faddr.s_addr != INADDR_ANY)
		return EISCONN;
	error = 0;
	s = splnet();
	if (error == 0) {
		sin = (struct sockaddr_in *)nam;
		error = in_pcbconnect(inp, nam, p);
	}
	splx(s);
	if (error == 0)
		soisconnected(so);
	return error;
}

static int
udp_detach(struct socket *so)
{
	struct inpcb *inp;
	int s;

	inp = sotoinpcb(so);
	if (inp == 0)
		return EINVAL;
	s = splnet();
	in_pcbdetach(inp);
	splx(s);
	return 0;
}

static int
udp_disconnect(struct socket *so)
{
	struct inpcb *inp;
	int s;

	inp = sotoinpcb(so);
	if (inp == 0)
		return EINVAL;
	if (inp->inp_faddr.s_addr == INADDR_ANY)
		return ENOTCONN;

	s = splnet();
	in_pcbdisconnect(inp);
	inp->inp_laddr.s_addr = INADDR_ANY;
	splx(s);
	so->so_state &= ~SS_ISCONNECTED;		/* XXX */
	return 0;
}

static int
udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
	    struct mbuf *control, struct proc *p)
{
	struct inpcb *inp;

	inp = sotoinpcb(so);
	if (inp == 0) {
		m_freem(m);
		return EINVAL;
	}
	return udp_output(inp, m, addr, control, p);
}

int
udp_shutdown(struct socket *so)
{
	struct inpcb *inp;

	inp = sotoinpcb(so);
	if (inp == 0)
		return EINVAL;
	socantsendmore(so);
	return 0;
}

struct pr_usrreqs udp_usrreqs = {
	udp_abort, pru_accept_notsupp, udp_attach, udp_bind, udp_connect, 
	pru_connect2_notsupp, in_control, udp_detach, udp_disconnect, 
	pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp, 
	pru_rcvoob_notsupp, udp_send, pru_sense_null, udp_shutdown,
	in_setsockaddr, sosend, soreceive, sopoll
};