/* * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $Id: ip_divert.c,v 1.12 1997/06/02 05:02:35 julian Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Divert sockets */ /* * Allocate enough space to hold a full IP packet */ #define DIVSNDQ (65536 + 100) #define DIVRCVQ (65536 + 100) /* Global variables */ /* * ip_input() and ip_output() set this secret value before calling us to * let us know which divert port to divert a packet to; this is done so * we can use the existing prototype for struct protosw's pr_input(). * This is stored in host order. */ u_short ip_divert_port; /* * We set this value to a non-zero port number when we want the call to * ip_fw_chk() in ip_input() or ip_output() to ignore ``divert '' * chain entries. This is stored in host order. */ u_short ip_divert_ignore; /* Internal variables */ static struct inpcbhead divcb; static struct inpcbinfo divcbinfo; static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */ static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */ /* Optimization: have this preinitialized */ static struct sockaddr_in divsrc = { sizeof(divsrc), AF_INET }; /* Internal functions */ static int div_output(struct socket *so, struct mbuf *m, struct mbuf *addr, struct mbuf *control); /* * Initialize divert connection block queue. */ void div_init(void) { LIST_INIT(&divcb); divcbinfo.listhead = &divcb; /* * XXX We don't use the hash list for divert IP, but it's easier * to allocate a one entry hash list than it is to check all * over the place for hashbase == NULL. */ divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask); } /* * Setup generic address and protocol structures * for div_input routine, then pass them along with * mbuf chain. ip->ip_len is assumed to have had * the header length (hlen) subtracted out already. * We tell whether the packet was incoming or outgoing * by seeing if hlen == 0, which is a hack. */ void div_input(struct mbuf *m, int hlen) { struct ip *ip; struct inpcb *inp; struct socket *sa; /* Sanity check */ if (ip_divert_port == 0) panic("div_input: port is 0"); /* Assure header */ if (m->m_len < sizeof(struct ip) && (m = m_pullup(m, sizeof(struct ip))) == 0) { return; } ip = mtod(m, struct ip *); /* Record divert port */ divsrc.sin_port = htons(ip_divert_port); /* Restore packet header fields */ ip->ip_len += hlen; HTONS(ip->ip_len); HTONS(ip->ip_off); /* Record receive interface address, if any */ divsrc.sin_addr.s_addr = 0; if (hlen) { struct ifaddr *ifa; #ifdef DIAGNOSTIC /* Sanity check */ if (!(m->m_flags & M_PKTHDR)) panic("div_input: no pkt hdr"); #endif /* More fields affected by ip_input() */ HTONS(ip->ip_id); /* Find IP address for recieve interface */ for (ifa = m->m_pkthdr.rcvif->if_addrhead.tqh_first; ifa != NULL; ifa = ifa->ifa_link.tqe_next) { if (ifa->ifa_addr == NULL) continue; if (ifa->ifa_addr->sa_family != AF_INET) continue; divsrc.sin_addr = ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr; break; } } /* Put packet on socket queue, if any */ sa = NULL; for (inp = divcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) { if (inp->inp_lport == htons(ip_divert_port)) sa = inp->inp_socket; } if (sa) { if (sbappendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc, m, (struct mbuf *)0) == 0) m_freem(m); else sorwakeup(sa); } else { m_freem(m); ipstat.ips_noproto++; ipstat.ips_delivered--; } } /* * Deliver packet back into the IP processing machinery. * * If no address specified, or address is 0.0.0.0, send to ip_output(); * otherwise, send to ip_input() and mark as having been received on * the interface with that address. * * If no address specified, or dest port is 0, allow packet to divert * back to this socket; otherwise, don't. */ static int div_output(so, m, addr, control) struct socket *so; register struct mbuf *m; struct mbuf *addr, *control; { register struct inpcb *const inp = sotoinpcb(so); register struct ip *const ip = mtod(m, struct ip *); struct sockaddr_in *sin = NULL; int error = 0; if (control) m_freem(control); /* XXX */ if (addr) sin = mtod(addr, struct sockaddr_in *); /* Loopback avoidance option */ ip_divert_ignore = ntohs(inp->inp_lport); /* Reinject packet into the system as incoming or outgoing */ if (!sin || sin->sin_addr.s_addr == 0) { /* Don't allow both user specified and setsockopt options, and don't allow packet length sizes that will crash */ if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) || ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) { error = EINVAL; goto cantsend; } /* Convert fields to host order for ip_output() */ NTOHS(ip->ip_len); NTOHS(ip->ip_off); /* Send packet to output processing */ ipstat.ips_rawout++; /* XXX */ error = ip_output(m, inp->inp_options, &inp->inp_route, (so->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST | IP_RAWOUTPUT, inp->inp_moptions); } else { struct ifaddr *ifa; /* Find receive interface with the given IP address */ sin->sin_port = 0; if ((ifa = ifa_ifwithaddr((struct sockaddr *) sin)) == 0) { error = EADDRNOTAVAIL; goto cantsend; } m->m_pkthdr.rcvif = ifa->ifa_ifp; /* Send packet to input processing */ ip_input(m); } /* Reset for next time (and other packets) */ ip_divert_ignore = 0; return error; cantsend: ip_divert_ignore = 0; m_freem(m); return error; } static int div_attach(struct socket *so, int proto, struct proc *p) { struct inpcb *inp; int error; inp = sotoinpcb(so); if (inp) panic("div_attach"); if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0) return error; if ((error = soreserve(so, div_sendspace, div_recvspace)) || (error = in_pcballoc(so, &divcbinfo, p))) return error; inp = (struct inpcb *)so->so_pcb; inp->inp_ip_p = proto; inp->inp_flags |= INP_HDRINCL; /* The socket is always "connected" because we always know "where" to send the packet */ so->so_state |= SS_ISCONNECTED; return 0; } static int div_detach(struct socket *so) { struct inpcb *inp; inp = sotoinpcb(so); if (inp == 0) panic("div_detach"); in_pcbdetach(inp); return 0; } static int div_abort(struct socket *so) { soisdisconnected(so); return div_detach(so); } static int div_disconnect(struct socket *so) { if ((so->so_state & SS_ISCONNECTED) == 0) return ENOTCONN; return div_abort(so); } static int div_bind(struct socket *so, struct mbuf *nam, struct proc *p) { struct inpcb *inp; int s; int error; s = splnet(); inp = sotoinpcb(so); error = in_pcbbind(inp, nam, p); splx(s); return 0; } static int div_shutdown(struct socket *so) { socantsendmore(so); return 0; } static int div_send(struct socket *so, int flags, struct mbuf *m, struct mbuf *nam, struct mbuf *control, struct proc *p) { /* Packet must have a header (but that's about it) */ if (m->m_len < sizeof (struct ip) || (m = m_pullup(m, sizeof (struct ip))) == 0) { ipstat.ips_toosmall++; m_freem(m); return EINVAL; } /* Send packet */ return div_output(so, m, nam, control); } struct pr_usrreqs div_usrreqs = { div_abort, pru_accept_notsupp, div_attach, div_bind, pru_connect_notsupp, pru_connect2_notsupp, in_control, div_detach, div_disconnect, pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp, pru_rcvoob_notsupp, div_send, pru_sense_null, div_shutdown, in_setsockaddr, sosend, soreceive, soselect };