/* * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 * 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. * * @(#)udp_usrreq.c 8.6 (Berkeley) 5/23/95 * $Id: udp_usrreq.c,v 1.43 1998/01/25 17:25:41 steve Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * UDP protocol implementation. * Per RFC 768, August, 1980. */ #ifndef COMPAT_42 static int udpcksum = 1; #else static int udpcksum = 0; /* XXX */ #endif SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW, &udpcksum, 0, ""); static int log_in_vain = 0; SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW, &log_in_vain, 0, ""); static struct inpcbhead udb; /* from udp_var.h */ static struct inpcbinfo udbinfo; #ifndef UDBHASHSIZE #define UDBHASHSIZE 16 #endif static struct udpstat udpstat; /* from udp_var.h */ SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RD, &udpstat, udpstat, ""); static struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; static int udp_output __P((struct inpcb *, struct mbuf *, struct sockaddr *, struct mbuf *, struct proc *)); static void udp_notify __P((struct inpcb *, int)); void udp_init() { LIST_INIT(&udb); udbinfo.listhead = &udb; udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask); udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.porthashmask); } void udp_input(m, iphlen) register struct mbuf *m; int iphlen; { register struct ip *ip; register struct udphdr *uh; register struct inpcb *inp; struct mbuf *opts = 0; int len; struct ip save_ip; udpstat.udps_ipackets++; /* * Strip IP options, if any; should skip this, * make available to user, and use on returned packets, * but we don't yet have a way to check the checksum * with options still present. */ if (iphlen > sizeof (struct ip)) { ip_stripoptions(m, (struct mbuf *)0); iphlen = sizeof(struct ip); } /* * Get IP and UDP header together in first mbuf. */ ip = mtod(m, struct ip *); if (m->m_len < iphlen + sizeof(struct udphdr)) { if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) { udpstat.udps_hdrops++; return; } ip = mtod(m, struct ip *); } uh = (struct udphdr *)((caddr_t)ip + iphlen); /* * Make mbuf data length reflect UDP length. * If not enough data to reflect UDP length, drop. */ len = ntohs((u_short)uh->uh_ulen); if (ip->ip_len != len) { if (len > ip->ip_len || len < sizeof(struct udphdr)) { udpstat.udps_badlen++; goto bad; } m_adj(m, len - ip->ip_len); /* ip->ip_len = len; */ } /* * Save a copy of the IP header in case we want restore it * for sending an ICMP error message in response. */ save_ip = *ip; /* * Checksum extended UDP header and data. */ if (uh->uh_sum) { ((struct ipovly *)ip)->ih_next = 0; ((struct ipovly *)ip)->ih_prev = 0; ((struct ipovly *)ip)->ih_x1 = 0; ((struct ipovly *)ip)->ih_len = uh->uh_ulen; uh->uh_sum = in_cksum(m, len + sizeof (struct ip)); if (uh->uh_sum) { udpstat.udps_badsum++; m_freem(m); return; } } if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { struct inpcb *last; /* * Deliver a multicast or broadcast datagram to *all* sockets * for which the local and remote addresses and ports match * those of the incoming datagram. This allows more than * one process to receive multi/broadcasts on the same port. * (This really ought to be done for unicast datagrams as * well, but that would cause problems with existing * applications that open both address-specific sockets and * a wildcard socket listening to the same port -- they would * end up receiving duplicates of every unicast datagram. * Those applications open the multiple sockets to overcome an * inadequacy of the UDP socket interface, but for backwards * compatibility we avoid the problem here rather than * fixing the interface. Maybe 4.5BSD will remedy this?) */ /* * Construct sockaddr format source address. */ udp_in.sin_port = uh->uh_sport; udp_in.sin_addr = ip->ip_src; m->m_len -= sizeof (struct udpiphdr); m->m_data += sizeof (struct udpiphdr); /* * Locate pcb(s) for datagram. * (Algorithm copied from raw_intr().) */ last = NULL; for (inp = udb.lh_first; inp != NULL; inp = inp->inp_list.le_next) { if (inp->inp_lport != uh->uh_dport) continue; if (inp->inp_laddr.s_addr != INADDR_ANY) { if (inp->inp_laddr.s_addr != ip->ip_dst.s_addr) continue; } if (inp->inp_faddr.s_addr != INADDR_ANY) { if (inp->inp_faddr.s_addr != ip->ip_src.s_addr || inp->inp_fport != uh->uh_sport) continue; } if (last != NULL) { struct mbuf *n; if ((n = m_copy(m, 0, M_COPYALL)) != NULL) { if (last->inp_flags & INP_CONTROLOPTS || last->inp_socket->so_options & SO_TIMESTAMP) ip_savecontrol(last, &opts, ip, n); if (sbappendaddr(&last->inp_socket->so_rcv, (struct sockaddr *)&udp_in, n, opts) == 0) { m_freem(n); if (opts) m_freem(opts); udpstat.udps_fullsock++; } else sorwakeup(last->inp_socket); opts = 0; } } last = inp; /* * Don't look for additional matches if this one does * not have either the SO_REUSEPORT or SO_REUSEADDR * socket options set. This heuristic avoids searching * through all pcbs in the common case of a non-shared * port. It * assumes that an application will never * clear these options after setting them. */ if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR)) == 0) break; } if (last == NULL) { /* * No matching pcb found; discard datagram. * (No need to send an ICMP Port Unreachable * for a broadcast or multicast datgram.) */ udpstat.udps_noportbcast++; goto bad; } if (last->inp_flags & INP_CONTROLOPTS || last->inp_socket->so_options & SO_TIMESTAMP) ip_savecontrol(last, &opts, ip, m); if (sbappendaddr(&last->inp_socket->so_rcv, (struct sockaddr *)&udp_in, m, opts) == 0) { udpstat.udps_fullsock++; goto bad; } sorwakeup(last->inp_socket); return; } /* * Locate pcb for datagram. */ inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport, ip->ip_dst, uh->uh_dport, 1); if (inp == NULL) { if (log_in_vain) { char buf[4*sizeof "123"]; strcpy(buf, inet_ntoa(ip->ip_dst)); log(LOG_INFO, "Connection attempt to UDP %s:%d from %s:%d\n", buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src), ntohs(uh->uh_sport)); } udpstat.udps_noport++; if (m->m_flags & (M_BCAST | M_MCAST)) { udpstat.udps_noportbcast++; goto bad; } *ip = save_ip; icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0); return; } /* * Construct sockaddr format source address. * Stuff source address and datagram in user buffer. */ udp_in.sin_port = uh->uh_sport; udp_in.sin_addr = ip->ip_src; if (inp->inp_flags & INP_CONTROLOPTS || inp->inp_socket->so_options & SO_TIMESTAMP) ip_savecontrol(inp, &opts, ip, m); iphlen += sizeof(struct udphdr); m->m_len -= iphlen; m->m_pkthdr.len -= iphlen; m->m_data += iphlen; if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, m, opts) == 0) { udpstat.udps_fullsock++; goto bad; } sorwakeup(inp->inp_socket); return; bad: m_freem(m); if (opts) m_freem(opts); } /* * Notify a udp user of an asynchronous error; * just wake up so that he can collect error status. */ static 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; { register struct ip *ip = vip; register struct udphdr *uh; if (!PRC_IS_REDIRECT(cmd) && ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)) return; if (ip) { uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, cmd, udp_notify); } else in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify); } static int udp_output(inp, m, addr, control, p) register struct inpcb *inp; register 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; 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, 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 *); 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; /* XXX rehash? */ splx(s); } return (error); release: m_freem(m); return (error); } 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, ""); 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; s = splnet(); error = in_pcballoc(so, &udbinfo, p); splx(s); if (error) return error; error = soreserve(so, udp_sendspace, udp_recvspace); if (error) return error; ((struct inpcb *) so->so_pcb)->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; inp = sotoinpcb(so); if (inp == 0) return EINVAL; if (inp->inp_faddr.s_addr != INADDR_ANY) return EISCONN; s = splnet(); 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); } static 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 };