sys/netinet/in_pcb.c

/*
 * Copyright (c) 1982, 1986, 1991, 1993 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)in_pcb.c	7.27 (Berkeley) 05/31/93
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/proc.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>

#include <netinet/ip_var.h>

struct	in_addr zeroin_addr;

in_pcballoc(so, head)
	struct socket *so;
	struct inpcb *head;
{
	struct mbuf *m;
	register struct inpcb *inp;

	MALLOC(inp, struct inpcb *, sizeof(*inp), M_PCB, M_WAITOK);
	if (inp == NULL)
		return (ENOBUFS);
	bzero((caddr_t)inp, sizeof(*inp));
	inp->inp_head = head;
	inp->inp_socket = so;
	insque(inp, head);
	so->so_pcb = (caddr_t)inp;
	return (0);
}

in_pcbbind(inp, nam)
	register struct inpcb *inp;
	struct mbuf *nam;
{
	register struct socket *so = inp->inp_socket;
	register struct inpcb *head = inp->inp_head;
	register struct sockaddr_in *sin;
	struct proc *p = curproc;		/* XXX */
	u_short lport = 0;
	int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
	int error;

	if (in_ifaddr == 0)
		return (EADDRNOTAVAIL);
	if (inp->inp_lport || inp->inp_laddr.s_addr != INADDR_ANY)
		return (EINVAL);
	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
	     (so->so_options & SO_ACCEPTCONN) == 0))
		wild = INPLOOKUP_WILDCARD;
	if (nam) {
		sin = mtod(nam, struct sockaddr_in *);
		if (nam->m_len != sizeof (*sin))
			return (EINVAL);
#ifdef notdef
		/*
		 * We should check the family, but old programs
		 * incorrectly fail to initialize it.
		 */
		if (sin->sin_family != AF_INET)
			return (EAFNOSUPPORT);
#endif
		lport = sin->sin_port;
		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
			/*
			 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
			 * allow complete duplication of binding if
			 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
			 * and a multicast address is bound on both
			 * new and duplicated sockets.
			 */
			if (so->so_options & SO_REUSEADDR)
				reuseport = SO_REUSEADDR|SO_REUSEPORT;
		} else if (sin->sin_addr.s_addr != INADDR_ANY) {
			sin->sin_port = 0;		/* yech... */
			if (ifa_ifwithaddr((struct sockaddr *)sin) == 0)
				return (EADDRNOTAVAIL);
		}
		if (lport) {
			struct inpcb *t;

			/* GROSS */
			if (ntohs(lport) < IPPORT_RESERVED &&
			    (error = suser(p->p_ucred, &p->p_acflag)))
				return (error);
			t = in_pcblookup(head, zeroin_addr, 0,
			    sin->sin_addr, lport, wild);
			if (t && (reuseport & t->inp_socket->so_options) == 0)
				return (EADDRINUSE);
		}
		inp->inp_laddr = sin->sin_addr;
	}
	if (lport == 0)
		do {
			if (head->inp_lport++ < IPPORT_RESERVED ||
			    head->inp_lport > IPPORT_USERRESERVED)
				head->inp_lport = IPPORT_RESERVED;
			lport = htons(head->inp_lport);
		} while (in_pcblookup(head,
			    zeroin_addr, 0, inp->inp_laddr, lport, wild));
	inp->inp_lport = lport;
	return (0);
}

/*
 * Connect from a socket to a specified address.
 * Both address and port must be specified in argument sin.
 * If don't have a local address for this socket yet,
 * then pick one.
 */
in_pcbconnect(inp, nam)
	register struct inpcb *inp;
	struct mbuf *nam;
{
	struct in_ifaddr *ia;
	struct sockaddr_in *ifaddr;
	register struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *);

	if (nam->m_len != sizeof (*sin))
		return (EINVAL);
	if (sin->sin_family != AF_INET)
		return (EAFNOSUPPORT);
	if (sin->sin_port == 0)
		return (EADDRNOTAVAIL);
	if (in_ifaddr) {
		/*
		 * If the destination address is INADDR_ANY,
		 * use the primary local address.
		 * If the supplied address is INADDR_BROADCAST,
		 * and the primary interface supports broadcast,
		 * choose the broadcast address for that interface.
		 */
#define	satosin(sa)	((struct sockaddr_in *)(sa))
#define sintosa(sin)	((struct sockaddr *)(sin))
#define ifatoia(ifa)	((struct in_ifaddr *)(ifa))
		if (sin->sin_addr.s_addr == INADDR_ANY)
		    sin->sin_addr = IA_SIN(in_ifaddr)->sin_addr;
		else if (sin->sin_addr.s_addr == (u_long)INADDR_BROADCAST &&
		  (in_ifaddr->ia_ifp->if_flags & IFF_BROADCAST))
		    sin->sin_addr = satosin(&in_ifaddr->ia_broadaddr)->sin_addr;
	}
	if (inp->inp_laddr.s_addr == INADDR_ANY) {
		register struct route *ro;

		ia = (struct in_ifaddr *)0;
		/*
		 * If route is known or can be allocated now,
		 * our src addr is taken from the i/f, else punt.
		 */
		ro = &inp->inp_route;
		if (ro->ro_rt &&
		    (satosin(&ro->ro_dst)->sin_addr.s_addr !=
			sin->sin_addr.s_addr ||
		    inp->inp_socket->so_options & SO_DONTROUTE)) {
			RTFREE(ro->ro_rt);
			ro->ro_rt = (struct rtentry *)0;
		}
		if ((inp->inp_socket->so_options & SO_DONTROUTE) == 0 && /*XXX*/
		    (ro->ro_rt == (struct rtentry *)0 ||
		    ro->ro_rt->rt_ifp == (struct ifnet *)0)) {
			/* No route yet, so try to acquire one */
			ro->ro_dst.sa_family = AF_INET;
			ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
			((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
				sin->sin_addr;
			rtalloc(ro);
		}
		/*
		 * If we found a route, use the address
		 * corresponding to the outgoing interface
		 * unless it is the loopback (in case a route
		 * to our address on another net goes to loopback).
		 */
		if (ro->ro_rt && !(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK))
			ia = ifatoia(ro->ro_rt->rt_ifa);
		if (ia == 0) {
			int fport = sin->sin_port;

			sin->sin_port = 0;
			ia = ifatoia(ifa_ifwithdstaddr(sintosa(sin)));
			if (ia == 0)
				ia = ifatoia(ifa_ifwithnet(sintosa(sin)));
			sin->sin_port = fport;
			if (ia == 0)
				ia = in_ifaddr;
			if (ia == 0)
				return (EADDRNOTAVAIL);
		}
		/*
		 * If the destination address is multicast and an outgoing
		 * interface has been set as a multicast option, use the
		 * address of that interface as our source address.
		 */
		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)) &&
		    inp->inp_moptions != NULL) {
			struct ip_moptions *imo;
			struct ifnet *ifp;

			imo = inp->inp_moptions;
			if (imo->imo_multicast_ifp != NULL) {
				ifp = imo->imo_multicast_ifp;
				for (ia = in_ifaddr; ia; ia = ia->ia_next)
					if (ia->ia_ifp == ifp)
						break;
				if (ia == 0)
					return (EADDRNOTAVAIL);
			}
		}
		ifaddr = (struct sockaddr_in *)&ia->ia_addr;
	}
	if (in_pcblookup(inp->inp_head,
	    sin->sin_addr,
	    sin->sin_port,
	    inp->inp_laddr.s_addr ? inp->inp_laddr : ifaddr->sin_addr,
	    inp->inp_lport,
	    0))
		return (EADDRINUSE);
	if (inp->inp_laddr.s_addr == INADDR_ANY) {
		if (inp->inp_lport == 0)
			(void)in_pcbbind(inp, (struct mbuf *)0);
		inp->inp_laddr = ifaddr->sin_addr;
	}
	inp->inp_faddr = sin->sin_addr;
	inp->inp_fport = sin->sin_port;
	return (0);
}

in_pcbdisconnect(inp)
	struct inpcb *inp;
{

	inp->inp_faddr.s_addr = INADDR_ANY;
	inp->inp_fport = 0;
	if (inp->inp_socket->so_state & SS_NOFDREF)
		in_pcbdetach(inp);
}

in_pcbdetach(inp)
	struct inpcb *inp;
{
	struct socket *so = inp->inp_socket;

	so->so_pcb = 0;
	sofree(so);
	if (inp->inp_options)
		(void)m_free(inp->inp_options);
	if (inp->inp_route.ro_rt)
		rtfree(inp->inp_route.ro_rt);
	ip_freemoptions(inp->inp_moptions);
	remque(inp);
	FREE(inp, M_PCB);
}

in_setsockaddr(inp, nam)
	register struct inpcb *inp;
	struct mbuf *nam;
{
	register struct sockaddr_in *sin;

	nam->m_len = sizeof (*sin);
	sin = mtod(nam, struct sockaddr_in *);
	bzero((caddr_t)sin, sizeof (*sin));
	sin->sin_family = AF_INET;
	sin->sin_len = sizeof(*sin);
	sin->sin_port = inp->inp_lport;
	sin->sin_addr = inp->inp_laddr;
}

in_setpeeraddr(inp, nam)
	struct inpcb *inp;
	struct mbuf *nam;
{
	register struct sockaddr_in *sin;

	nam->m_len = sizeof (*sin);
	sin = mtod(nam, struct sockaddr_in *);
	bzero((caddr_t)sin, sizeof (*sin));
	sin->sin_family = AF_INET;
	sin->sin_len = sizeof(*sin);
	sin->sin_port = inp->inp_fport;
	sin->sin_addr = inp->inp_faddr;
}

/*
 * Pass some notification to all connections of a protocol
 * associated with address dst.  The local address and/or port numbers
 * may be specified to limit the search.  The "usual action" will be
 * taken, depending on the ctlinput cmd.  The caller must filter any
 * cmds that are uninteresting (e.g., no error in the map).
 * Call the protocol specific routine (if any) to report
 * any errors for each matching socket.
 *
 * Must be called at splnet.
 */
in_pcbnotify(head, dst, fport, laddr, lport, cmd, notify)
	struct inpcb *head;
	struct sockaddr *dst;
	u_short fport, lport;
	struct in_addr laddr;
	int cmd, (*notify)();
{
	register struct inpcb *inp, *oinp;
	struct in_addr faddr;
	int errno;
	int in_rtchange();
	extern u_char inetctlerrmap[];

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

	/*
	 * Redirects go to all references to the destination,
	 * and use in_rtchange to invalidate the route cache.
	 * Dead host indications: notify all references to the destination.
	 * Otherwise, if we have knowledge of the local port and address,
	 * deliver only to that socket.
	 */
	if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
		fport = 0;
		lport = 0;
		laddr.s_addr = 0;
		if (cmd != PRC_HOSTDEAD)
			notify = in_rtchange;
	}
	errno = inetctlerrmap[cmd];
	for (inp = head->inp_next; inp != head;) {
		if (inp->inp_faddr.s_addr != faddr.s_addr ||
		    inp->inp_socket == 0 ||
		    (lport && inp->inp_lport != lport) ||
		    (laddr.s_addr && inp->inp_laddr.s_addr != laddr.s_addr) ||
		    (fport && inp->inp_fport != fport)) {
			inp = inp->inp_next;
			continue;
		}
		oinp = inp;
		inp = inp->inp_next;
		if (notify)
			(*notify)(oinp, errno);
	}
}

/*
 * Check for alternatives when higher level complains
 * about service problems.  For now, invalidate cached
 * routing information.  If the route was created dynamically
 * (by a redirect), time to try a default gateway again.
 */
in_losing(inp)
	struct inpcb *inp;
{
	register struct rtentry *rt;
	struct rt_addrinfo info;

	if ((rt = inp->inp_route.ro_rt)) {
		inp->inp_route.ro_rt = 0;
		bzero((caddr_t)&info, sizeof(info));
		info.rti_info[RTAX_DST] =
			(struct sockaddr *)&inp->inp_route.ro_dst;
		info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
		info.rti_info[RTAX_NETMASK] = rt_mask(rt);
		rt_missmsg(RTM_LOSING, &info, rt->rt_flags, 0);
		if (rt->rt_flags & RTF_DYNAMIC)
			(void) rtrequest(RTM_DELETE, rt_key(rt),
				rt->rt_gateway, rt_mask(rt), rt->rt_flags,
				(struct rtentry **)0);
		else
		/*
		 * A new route can be allocated
		 * the next time output is attempted.
		 */
			rtfree(rt);
	}
}

/*
 * After a routing change, flush old routing
 * and allocate a (hopefully) better one.
 */
in_rtchange(inp)
	register struct inpcb *inp;
{
	if (inp->inp_route.ro_rt) {
		rtfree(inp->inp_route.ro_rt);
		inp->inp_route.ro_rt = 0;
		/*
		 * A new route can be allocated the next time
		 * output is attempted.
		 */
	}
}

struct inpcb *
in_pcblookup(head, faddr, fport, laddr, lport, flags)
	struct inpcb *head;
	struct in_addr faddr, laddr;
	u_short fport, lport;
	int flags;
{
	register struct inpcb *inp, *match = 0;
	int matchwild = 3, wildcard;

	for (inp = head->inp_next; inp != head; inp = inp->inp_next) {
		if (inp->inp_lport != lport)
			continue;
		wildcard = 0;
		if (inp->inp_laddr.s_addr != INADDR_ANY) {
			if (laddr.s_addr == INADDR_ANY)
				wildcard++;
			else if (inp->inp_laddr.s_addr != laddr.s_addr)
				continue;
		} else {
			if (laddr.s_addr != INADDR_ANY)
				wildcard++;
		}
		if (inp->inp_faddr.s_addr != INADDR_ANY) {
			if (faddr.s_addr == INADDR_ANY)
				wildcard++;
			else if (inp->inp_faddr.s_addr != faddr.s_addr ||
			    inp->inp_fport != fport)
				continue;
		} else {
			if (faddr.s_addr != INADDR_ANY)
				wildcard++;
		}
		if (wildcard && (flags & INPLOOKUP_WILDCARD) == 0)
			continue;
		if (wildcard < matchwild) {
			match = inp;
			matchwild = wildcard;
			if (matchwild == 0)
				break;
		}
	}
	return (match);
}