usr/src/sys/netinet/in_pcb.c

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)in_pcb.c    7.9 (Berkeley) %G%
 */

#include "param.h"
#include "systm.h"
#include "dir.h"
#include "user.h"
#include "malloc.h"
#include "mbuf.h"
#include "socket.h"
#include "socketvar.h"
#include "ioctl.h"
#include "in.h"
#include "in_systm.h"
#include "../net/if.h"
#include "../net/route.h"
#include "in_pcb.h"
#include "in_var.h"
#include "protosw.h"

struct  in_addr zeroin_addr;

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

        m = m_getclr(M_DONTWAIT, MT_PCB);
        if (m == NULL)
                return (ENOBUFS);
        inp = mtod(m, struct inpcb *);
        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;
        u_short lport = 0;

        if (in_ifaddr == 0)
                return (EADDRNOTAVAIL);
        if (inp->inp_lport || inp->inp_laddr.s_addr != INADDR_ANY)
                return (EINVAL);
        if (nam == 0)
                goto noname;
        sin = mtod(nam, struct sockaddr_in *);
        if (nam->m_len != sizeof (*sin))
                return (EINVAL);
        if (sin->sin_addr.s_addr != INADDR_ANY) {
                int tport = sin->sin_port;

                sin->sin_port = 0;              /* yech... */
                if (ifa_ifwithaddr((struct sockaddr *)sin) == 0)
                        return (EADDRNOTAVAIL);
                sin->sin_port = tport;
        }
        lport = sin->sin_port;
        if (lport) {
                u_short aport = ntohs(lport);
                int wild = 0;

                /* GROSS */
                if (aport < IPPORT_RESERVED && u.u_uid != 0)
                        return (EACCES);
                /* even GROSSER, but this is the Internet */
                if ((so->so_options & SO_REUSEADDR) == 0 &&
                    ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
                     (so->so_options & SO_ACCEPTCONN) == 0))
                        wild = INPLOOKUP_WILDCARD;
                if (in_pcblookup(head,
                    zeroin_addr, 0, sin->sin_addr, lport, wild))
                        return (EADDRINUSE);
        }
        inp->inp_laddr = sin->sin_addr;
noname:
        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, 0));
        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))
                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;
                struct ifnet *ifp;

                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 && (ifp = ro->ro_rt->rt_ifp) &&
                    (ifp->if_flags & IFF_LOOPBACK) == 0)
                        for (ia = in_ifaddr; ia; ia = ia->ia_next)
                                if (ia->ia_ifp == ifp)
                                        break;
                if (ia == 0) {
                        int fport = sin->sin_port;

                        sin->sin_port = 0;
                        ia = (struct in_ifaddr *)
                            ifa_ifwithdstaddr((struct sockaddr *)sin);
                        sin->sin_port = fport;
                        if (ia == 0)
                                ia = in_iaonnetof(in_netof(sin->sin_addr));
                        if (ia == 0)
                                ia = in_ifaddr;
                        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);
        remque(inp);
        (void) m_free(dtom(inp));
}

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.  Call the protocol specific
 * routine (if any) to handle each connection.
 */
in_pcbnotify(head, dst, errno, notify)
        struct inpcb *head;
        register struct in_addr *dst;
        int errno, (*notify)();
{
        register struct inpcb *inp, *oinp;
        int s = splimp();

        for (inp = head->inp_next; inp != head;) {
                if (inp->inp_faddr.s_addr != dst->s_addr ||
                    inp->inp_socket == 0) {
                        inp = inp->inp_next;
                        continue;
                }
                if (errno)
                        inp->inp_socket->so_error = errno;
                oinp = inp;
                inp = inp->inp_next;
                if (notify)
                        (*notify)(oinp);
        }
        splx(s);
}

/*
 * 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;

        if ((rt = inp->inp_route.ro_rt)) {
                rt_missmsg(RTM_LOSING, &inp->inp_route.ro_dst,
                            rt->rt_gateway, (struct sockaddr *)rt_mask(rt),
                            (struct sockaddr *)0, 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);
                inp->inp_route.ro_rt = 0;
                rtfree(rt);
                /*
                 * A new route can be allocated
                 * the next time output is attempted.
                 */
        }
}

/*
 * 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);
}