/* $OpenBSD: udp_usrreq.c,v 1.10 1997/06/27 02:23:22 deraadt Exp $ */ /* $NetBSD: udp_usrreq.c,v 1.28 1996/03/16 23:54:03 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1988, 1990, 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. * * @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94 */ #include #include #include #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. */ int udpcksum = 1; struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET }; static void udp_detach __P((struct inpcb *)); static void udp_notify __P((struct inpcb *, int)); static struct mbuf *udp_saveopt __P((caddr_t, int, int)); #ifndef UDBHASHSIZE #define UDBHASHSIZE 128 #endif int udbhashsize = UDBHASHSIZE; void udp_init() { in_pcbinit(&udbtable, udbhashsize); } void #if __STDC__ udp_input(struct mbuf *m, ...) #else udp_input(m, va_alist) struct mbuf *m; va_dcl #endif { register struct ip *ip; register struct udphdr *uh; register struct inpcb *inp; struct mbuf *opts = 0; int len; struct ip save_ip; int iphlen; va_list ap; va_start(ap, m); iphlen = va_arg(ap, int); va_end(ap); 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_int16_t)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. * from W.R.Stevens: check incoming udp cksums even if * udpcksum is not set. */ if (uh->uh_sum) { bzero(((struct ipovly *)ip)->ih_x1, sizeof ((struct ipovly *)ip)->ih_x1); ((struct ipovly *)ip)->ih_len = uh->uh_ulen; if ((uh->uh_sum = in_cksum(m, len + sizeof (struct ip))) != 0) { udpstat.udps_badsum++; m_freem(m); return; } } if (IN_MULTICAST(ip->ip_dst.s_addr) || in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) { struct socket *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 = udbtable.inpt_queue.cqh_first; inp != (struct inpcb *)&udbtable.inpt_queue; inp = inp->inp_queue.cqe_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 (sbappendaddr(&last->so_rcv, sintosa(&udp_in), n, (struct mbuf *)0) == 0) { m_freem(n); udpstat.udps_fullsock++; } else sorwakeup(last); } } last = inp->inp_socket; /* * 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->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 (sbappendaddr(&last->so_rcv, sintosa(&udp_in), m, (struct mbuf *)0) == 0) { udpstat.udps_fullsock++; goto bad; } sorwakeup(last); return; } /* * Locate pcb for datagram. */ inp = in_pcbhashlookup(&udbtable, ip->ip_src, uh->uh_sport, ip->ip_dst, uh->uh_dport); if (inp == 0) { ++udpstat.udps_pcbhashmiss; inp = in_pcblookup(&udbtable, ip->ip_src, uh->uh_sport, ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD); if (inp == 0) { 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) { struct mbuf **mp = &opts; if (inp->inp_flags & INP_RECVDSTADDR) { *mp = udp_saveopt((caddr_t) &ip->ip_dst, sizeof(struct in_addr), IP_RECVDSTADDR); if (*mp) mp = &(*mp)->m_next; } #ifdef notyet /* options were tossed above */ if (inp->inp_flags & INP_RECVOPTS) { *mp = udp_saveopt((caddr_t) opts_deleted_above, sizeof(struct in_addr), IP_RECVOPTS); if (*mp) mp = &(*mp)->m_next; } /* ip_srcroute doesn't do what we want here, need to fix */ if (inp->inp_flags & INP_RECVRETOPTS) { *mp = udp_saveopt((caddr_t) ip_srcroute(), sizeof(struct in_addr), IP_RECVRETOPTS); if (*mp) mp = &(*mp)->m_next; } #endif } iphlen += sizeof(struct udphdr); m->m_len -= iphlen; m->m_pkthdr.len -= iphlen; m->m_data += iphlen; if (sbappendaddr(&inp->inp_socket->so_rcv, sintosa(&udp_in), m, opts) == 0) { udpstat.udps_fullsock++; goto bad; } sorwakeup(inp->inp_socket); return; bad: m_freem(m); if (opts) m_freem(opts); } /* * Create a "control" mbuf containing the specified data * with the specified type for presentation with a datagram. */ struct mbuf * udp_saveopt(p, size, type) caddr_t p; register int size; int type; { register struct cmsghdr *cp; struct mbuf *m; if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL) return ((struct mbuf *) NULL); cp = (struct cmsghdr *) mtod(m, struct cmsghdr *); bcopy(p, CMSG_DATA(cp), size); size += sizeof(*cp); m->m_len = size; cp->cmsg_len = size; cp->cmsg_level = IPPROTO_IP; cp->cmsg_type = type; return (m); } /* * 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, v) int cmd; struct sockaddr *sa; void *v; { register struct ip *ip = v; register struct udphdr *uh; extern int inetctlerrmap[]; void (*notify) __P((struct inpcb *, int)) = udp_notify; int errno; if ((unsigned)cmd >= PRC_NCMDS) return NULL; errno = inetctlerrmap[cmd]; if (PRC_IS_REDIRECT(cmd)) notify = in_rtchange, ip = 0; else if (cmd == PRC_HOSTDEAD) ip = 0; else if (errno == 0) return NULL; if (ip) { uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2)); in_pcbnotify(&udbtable, sa, uh->uh_dport, ip->ip_src, uh->uh_sport, errno, notify); } else in_pcbnotifyall(&udbtable, sa, errno, notify); return NULL; } int #if __STDC__ udp_output(struct mbuf *m, ...) #else udp_output(m, va_alist) struct mbuf *m; va_dcl #endif { register struct inpcb *inp; struct mbuf *addr, *control; register struct udpiphdr *ui; register int len = m->m_pkthdr.len; struct in_addr laddr; int s = 0, error = 0; va_list ap; va_start(ap, m); inp = va_arg(ap, struct inpcb *); addr = va_arg(ap, struct mbuf *); control = va_arg(ap, struct mbuf *); va_end(ap); if (control) m_freem(control); /* XXX */ 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 = splsoftnet(); error = in_pcbconnect(inp, addr); 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; goto bail; } /* * Compute the packet length of the IP header, and * punt if the length looks bogus. */ if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) { error = EMSGSIZE; 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); ui->ui_pr = IPPROTO_UDP; ui->ui_len = htons((u_int16_t)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.ip_ttl; /* XXX */ ((struct ip *)ui)->ip_tos = inp->inp_ip.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); bail: if (addr) { in_pcbdisconnect(inp); inp->inp_laddr = laddr; splx(s); } return (error); release: m_freem(m); return (error); } u_long udp_sendspace = 9216; /* really max datagram size */ u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in)); /* 40 1K datagrams */ /*ARGSUSED*/ int udp_usrreq(so, req, m, addr, control) struct socket *so; int req; struct mbuf *m, *addr, *control; { struct inpcb *inp = sotoinpcb(so); int error = 0; int s; if (req == PRU_CONTROL) return (in_control(so, (long)m, (caddr_t)addr, (struct ifnet *)control)); if (inp == NULL && req != PRU_ATTACH) { error = EINVAL; goto release; } /* * Note: need to block udp_input while changing * the udp pcb queue and/or pcb addresses. */ switch (req) { case PRU_ATTACH: if (inp != NULL) { error = EINVAL; break; } s = splsoftnet(); error = in_pcballoc(so, &udbtable); splx(s); if (error) break; error = soreserve(so, udp_sendspace, udp_recvspace); if (error) break; ((struct inpcb *) so->so_pcb)->inp_ip.ip_ttl = ip_defttl; break; case PRU_DETACH: udp_detach(inp); break; case PRU_BIND: s = splsoftnet(); error = in_pcbbind(inp, addr); splx(s); break; case PRU_LISTEN: error = EOPNOTSUPP; break; case PRU_CONNECT: if (inp->inp_faddr.s_addr != INADDR_ANY) { error = EISCONN; break; } s = splsoftnet(); error = in_pcbconnect(inp, addr); splx(s); if (error == 0) soisconnected(so); break; case PRU_CONNECT2: error = EOPNOTSUPP; break; case PRU_ACCEPT: error = EOPNOTSUPP; break; case PRU_DISCONNECT: if (inp->inp_faddr.s_addr == INADDR_ANY) { error = ENOTCONN; break; } s = splsoftnet(); in_pcbdisconnect(inp); inp->inp_laddr.s_addr = INADDR_ANY; splx(s); so->so_state &= ~SS_ISCONNECTED; /* XXX */ break; case PRU_SHUTDOWN: socantsendmore(so); break; case PRU_SEND: return (udp_output(m, inp, addr, control)); case PRU_ABORT: soisdisconnected(so); udp_detach(inp); break; case PRU_SOCKADDR: in_setsockaddr(inp, addr); break; case PRU_PEERADDR: in_setpeeraddr(inp, addr); break; case PRU_SENSE: /* * stat: don't bother with a blocksize. */ return (0); case PRU_SENDOOB: case PRU_FASTTIMO: case PRU_SLOWTIMO: case PRU_PROTORCV: case PRU_PROTOSEND: error = EOPNOTSUPP; break; case PRU_RCVD: case PRU_RCVOOB: return (EOPNOTSUPP); /* do not free mbuf's */ default: panic("udp_usrreq"); } release: if (control) { printf("udp control data unexpectedly retained\n"); m_freem(control); } if (m) m_freem(m); return (error); } static void udp_detach(inp) struct inpcb *inp; { int s = splsoftnet(); in_pcbdetach(inp); splx(s); } /* * Sysctl for udp variables. */ int udp_sysctl(name, namelen, oldp, oldlenp, newp, newlen) int *name; u_int namelen; void *oldp; size_t *oldlenp; void *newp; size_t newlen; { /* All sysctl names at this level are terminal. */ if (namelen != 1) return (ENOTDIR); switch (name[0]) { case UDPCTL_CHECKSUM: return (sysctl_int(oldp, oldlenp, newp, newlen, &udpcksum)); default: return (ENOPROTOOPT); } /* NOTREACHED */ }