diff options
Diffstat (limited to 'sys/netinet/ip_output.c')
| -rw-r--r-- | sys/netinet/ip_output.c | 1064 |
1 files changed, 1064 insertions, 0 deletions
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c new file mode 100644 index 0000000..4c22a5e --- /dev/null +++ b/sys/netinet/ip_output.c @@ -0,0 +1,1064 @@ +/* + * 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. + * + * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 + */ + +#include <sys/param.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/errno.h> +#include <sys/protosw.h> +#include <sys/socket.h> +#include <sys/socketvar.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> + +#ifdef vax +#include <machine/mtpr.h> +#endif + +static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *)); +static void ip_mloopback + __P((struct ifnet *, struct mbuf *, struct sockaddr_in *)); + +/* + * IP output. The packet in mbuf chain m contains a skeletal IP + * header (with len, off, ttl, proto, tos, src, dst). + * The mbuf chain containing the packet will be freed. + * The mbuf opt, if present, will not be freed. + */ +int +ip_output(m0, opt, ro, flags, imo) + struct mbuf *m0; + struct mbuf *opt; + struct route *ro; + int flags; + struct ip_moptions *imo; +{ + register struct ip *ip, *mhip; + register struct ifnet *ifp; + register struct mbuf *m = m0; + register int hlen = sizeof (struct ip); + int len, off, error = 0; + struct route iproute; + struct sockaddr_in *dst; + struct in_ifaddr *ia; + +#ifdef DIAGNOSTIC + if ((m->m_flags & M_PKTHDR) == 0) + panic("ip_output no HDR"); +#endif + if (opt) { + m = ip_insertoptions(m, opt, &len); + hlen = len; + } + ip = mtod(m, struct ip *); + /* + * Fill in IP header. + */ + if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { + ip->ip_v = IPVERSION; + ip->ip_off &= IP_DF; + ip->ip_id = htons(ip_id++); + ip->ip_hl = hlen >> 2; + ipstat.ips_localout++; + } else { + hlen = ip->ip_hl << 2; + } + /* + * Route packet. + */ + if (ro == 0) { + ro = &iproute; + bzero((caddr_t)ro, sizeof (*ro)); + } + dst = (struct sockaddr_in *)&ro->ro_dst; + /* + * If there is a cached route, + * check that it is to the same destination + * and is still up. If not, free it and try again. + */ + if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || + dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { + RTFREE(ro->ro_rt); + ro->ro_rt = (struct rtentry *)0; + } + if (ro->ro_rt == 0) { + dst->sin_family = AF_INET; + dst->sin_len = sizeof(*dst); + dst->sin_addr = ip->ip_dst; + } + /* + * If routing to interface only, + * short circuit routing lookup. + */ +#define ifatoia(ifa) ((struct in_ifaddr *)(ifa)) +#define sintosa(sin) ((struct sockaddr *)(sin)) + if (flags & IP_ROUTETOIF) { + if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 && + (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) { + ipstat.ips_noroute++; + error = ENETUNREACH; + goto bad; + } + ifp = ia->ia_ifp; + ip->ip_ttl = 1; + } else { + if (ro->ro_rt == 0) + rtalloc(ro); + if (ro->ro_rt == 0) { + ipstat.ips_noroute++; + error = EHOSTUNREACH; + goto bad; + } + ia = ifatoia(ro->ro_rt->rt_ifa); + ifp = ro->ro_rt->rt_ifp; + ro->ro_rt->rt_use++; + if (ro->ro_rt->rt_flags & RTF_GATEWAY) + dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; + } + if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { + struct in_multi *inm; + extern struct ifnet loif; + + m->m_flags |= M_MCAST; + /* + * IP destination address is multicast. Make sure "dst" + * still points to the address in "ro". (It may have been + * changed to point to a gateway address, above.) + */ + dst = (struct sockaddr_in *)&ro->ro_dst; + /* + * See if the caller provided any multicast options + */ + if (imo != NULL) { + ip->ip_ttl = imo->imo_multicast_ttl; + if (imo->imo_multicast_ifp != NULL) + ifp = imo->imo_multicast_ifp; + } else + ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; + /* + * Confirm that the outgoing interface supports multicast. + */ + if ((ifp->if_flags & IFF_MULTICAST) == 0) { + ipstat.ips_noroute++; + error = ENETUNREACH; + goto bad; + } + /* + * If source address not specified yet, use address + * of outgoing interface. + */ + if (ip->ip_src.s_addr == INADDR_ANY) { + register struct in_ifaddr *ia; + + for (ia = in_ifaddr; ia; ia = ia->ia_next) + if (ia->ia_ifp == ifp) { + ip->ip_src = IA_SIN(ia)->sin_addr; + break; + } + } + + IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); + if (inm != NULL && + (imo == NULL || imo->imo_multicast_loop)) { + /* + * If we belong to the destination multicast group + * on the outgoing interface, and the caller did not + * forbid loopback, loop back a copy. + */ + ip_mloopback(ifp, m, dst); + } +#ifdef MROUTING + else { + /* + * If we are acting as a multicast router, perform + * multicast forwarding as if the packet had just + * arrived on the interface to which we are about + * to send. The multicast forwarding function + * recursively calls this function, using the + * IP_FORWARDING flag to prevent infinite recursion. + * + * Multicasts that are looped back by ip_mloopback(), + * above, will be forwarded by the ip_input() routine, + * if necessary. + */ + extern struct socket *ip_mrouter; + if (ip_mrouter && (flags & IP_FORWARDING) == 0) { + if (ip_mforward(m, ifp) != 0) { + m_freem(m); + goto done; + } + } + } +#endif + /* + * Multicasts with a time-to-live of zero may be looped- + * back, above, but must not be transmitted on a network. + * Also, multicasts addressed to the loopback interface + * are not sent -- the above call to ip_mloopback() will + * loop back a copy if this host actually belongs to the + * destination group on the loopback interface. + */ + if (ip->ip_ttl == 0 || ifp == &loif) { + m_freem(m); + goto done; + } + + goto sendit; + } +#ifndef notdef + /* + * If source address not specified yet, use address + * of outgoing interface. + */ + if (ip->ip_src.s_addr == INADDR_ANY) + ip->ip_src = IA_SIN(ia)->sin_addr; +#endif + /* + * Look for broadcast address and + * and verify user is allowed to send + * such a packet. + */ + if (in_broadcast(dst->sin_addr, ifp)) { + if ((ifp->if_flags & IFF_BROADCAST) == 0) { + error = EADDRNOTAVAIL; + goto bad; + } + if ((flags & IP_ALLOWBROADCAST) == 0) { + error = EACCES; + goto bad; + } + /* don't allow broadcast messages to be fragmented */ + if ((u_short)ip->ip_len > ifp->if_mtu) { + error = EMSGSIZE; + goto bad; + } + m->m_flags |= M_BCAST; + } else + m->m_flags &= ~M_BCAST; + +sendit: + /* + * If small enough for interface, can just send directly. + */ + if ((u_short)ip->ip_len <= ifp->if_mtu) { + ip->ip_len = htons((u_short)ip->ip_len); + ip->ip_off = htons((u_short)ip->ip_off); + ip->ip_sum = 0; + ip->ip_sum = in_cksum(m, hlen); + error = (*ifp->if_output)(ifp, m, + (struct sockaddr *)dst, ro->ro_rt); + goto done; + } + /* + * Too large for interface; fragment if possible. + * Must be able to put at least 8 bytes per fragment. + */ + if (ip->ip_off & IP_DF) { + error = EMSGSIZE; + ipstat.ips_cantfrag++; + goto bad; + } + len = (ifp->if_mtu - hlen) &~ 7; + if (len < 8) { + error = EMSGSIZE; + goto bad; + } + + { + int mhlen, firstlen = len; + struct mbuf **mnext = &m->m_nextpkt; + + /* + * Loop through length of segment after first fragment, + * make new header and copy data of each part and link onto chain. + */ + m0 = m; + mhlen = sizeof (struct ip); + for (off = hlen + len; off < (u_short)ip->ip_len; off += len) { + MGETHDR(m, M_DONTWAIT, MT_HEADER); + if (m == 0) { + error = ENOBUFS; + ipstat.ips_odropped++; + goto sendorfree; + } + m->m_data += max_linkhdr; + mhip = mtod(m, struct ip *); + *mhip = *ip; + if (hlen > sizeof (struct ip)) { + mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); + mhip->ip_hl = mhlen >> 2; + } + m->m_len = mhlen; + mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); + if (ip->ip_off & IP_MF) + mhip->ip_off |= IP_MF; + if (off + len >= (u_short)ip->ip_len) + len = (u_short)ip->ip_len - off; + else + mhip->ip_off |= IP_MF; + mhip->ip_len = htons((u_short)(len + mhlen)); + m->m_next = m_copy(m0, off, len); + if (m->m_next == 0) { + (void) m_free(m); + error = ENOBUFS; /* ??? */ + ipstat.ips_odropped++; + goto sendorfree; + } + m->m_pkthdr.len = mhlen + len; + m->m_pkthdr.rcvif = (struct ifnet *)0; + mhip->ip_off = htons((u_short)mhip->ip_off); + mhip->ip_sum = 0; + mhip->ip_sum = in_cksum(m, mhlen); + *mnext = m; + mnext = &m->m_nextpkt; + ipstat.ips_ofragments++; + } + /* + * Update first fragment by trimming what's been copied out + * and updating header, then send each fragment (in order). + */ + m = m0; + m_adj(m, hlen + firstlen - (u_short)ip->ip_len); + m->m_pkthdr.len = hlen + firstlen; + ip->ip_len = htons((u_short)m->m_pkthdr.len); + ip->ip_off = htons((u_short)(ip->ip_off | IP_MF)); + ip->ip_sum = 0; + ip->ip_sum = in_cksum(m, hlen); +sendorfree: + for (m = m0; m; m = m0) { + m0 = m->m_nextpkt; + m->m_nextpkt = 0; + if (error == 0) + error = (*ifp->if_output)(ifp, m, + (struct sockaddr *)dst, ro->ro_rt); + else + m_freem(m); + } + + if (error == 0) + ipstat.ips_fragmented++; + } +done: + if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) + RTFREE(ro->ro_rt); + return (error); +bad: + m_freem(m0); + goto done; +} + +/* + * Insert IP options into preformed packet. + * Adjust IP destination as required for IP source routing, + * as indicated by a non-zero in_addr at the start of the options. + */ +static struct mbuf * +ip_insertoptions(m, opt, phlen) + register struct mbuf *m; + struct mbuf *opt; + int *phlen; +{ + register struct ipoption *p = mtod(opt, struct ipoption *); + struct mbuf *n; + register struct ip *ip = mtod(m, struct ip *); + unsigned optlen; + + optlen = opt->m_len - sizeof(p->ipopt_dst); + if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) + return (m); /* XXX should fail */ + if (p->ipopt_dst.s_addr) + ip->ip_dst = p->ipopt_dst; + if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { + MGETHDR(n, M_DONTWAIT, MT_HEADER); + if (n == 0) + return (m); + n->m_pkthdr.len = m->m_pkthdr.len + optlen; + m->m_len -= sizeof(struct ip); + m->m_data += sizeof(struct ip); + n->m_next = m; + m = n; + m->m_len = optlen + sizeof(struct ip); + m->m_data += max_linkhdr; + bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); + } else { + m->m_data -= optlen; + m->m_len += optlen; + m->m_pkthdr.len += optlen; + ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); + } + ip = mtod(m, struct ip *); + bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen); + *phlen = sizeof(struct ip) + optlen; + ip->ip_len += optlen; + return (m); +} + +/* + * Copy options from ip to jp, + * omitting those not copied during fragmentation. + */ +int +ip_optcopy(ip, jp) + struct ip *ip, *jp; +{ + register u_char *cp, *dp; + int opt, optlen, cnt; + + cp = (u_char *)(ip + 1); + dp = (u_char *)(jp + 1); + cnt = (ip->ip_hl << 2) - sizeof (struct ip); + for (; cnt > 0; cnt -= optlen, cp += optlen) { + opt = cp[0]; + if (opt == IPOPT_EOL) + break; + if (opt == IPOPT_NOP) { + /* Preserve for IP mcast tunnel's LSRR alignment. */ + *dp++ = IPOPT_NOP; + optlen = 1; + continue; + } else + optlen = cp[IPOPT_OLEN]; + /* bogus lengths should have been caught by ip_dooptions */ + if (optlen > cnt) + optlen = cnt; + if (IPOPT_COPIED(opt)) { + bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); + dp += optlen; + } + } + for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) + *dp++ = IPOPT_EOL; + return (optlen); +} + +/* + * IP socket option processing. + */ +int +ip_ctloutput(op, so, level, optname, mp) + int op; + struct socket *so; + int level, optname; + struct mbuf **mp; +{ + register struct inpcb *inp = sotoinpcb(so); + register struct mbuf *m = *mp; + register int optval; + int error = 0; + + if (level != IPPROTO_IP) { + error = EINVAL; + if (op == PRCO_SETOPT && *mp) + (void) m_free(*mp); + } else switch (op) { + + case PRCO_SETOPT: + switch (optname) { + case IP_OPTIONS: +#ifdef notyet + case IP_RETOPTS: + return (ip_pcbopts(optname, &inp->inp_options, m)); +#else + return (ip_pcbopts(&inp->inp_options, m)); +#endif + + case IP_TOS: + case IP_TTL: + case IP_RECVOPTS: + case IP_RECVRETOPTS: + case IP_RECVDSTADDR: + if (m->m_len != sizeof(int)) + error = EINVAL; + else { + optval = *mtod(m, int *); + switch (optname) { + + case IP_TOS: + inp->inp_ip.ip_tos = optval; + break; + + case IP_TTL: + inp->inp_ip.ip_ttl = optval; + break; +#define OPTSET(bit) \ + if (optval) \ + inp->inp_flags |= bit; \ + else \ + inp->inp_flags &= ~bit; + + case IP_RECVOPTS: + OPTSET(INP_RECVOPTS); + break; + + case IP_RECVRETOPTS: + OPTSET(INP_RECVRETOPTS); + break; + + case IP_RECVDSTADDR: + OPTSET(INP_RECVDSTADDR); + break; + } + } + break; +#undef OPTSET + + case IP_MULTICAST_IF: + case IP_MULTICAST_TTL: + case IP_MULTICAST_LOOP: + case IP_ADD_MEMBERSHIP: + case IP_DROP_MEMBERSHIP: + error = ip_setmoptions(optname, &inp->inp_moptions, m); + break; + + default: + error = ENOPROTOOPT; + break; + } + if (m) + (void)m_free(m); + break; + + case PRCO_GETOPT: + switch (optname) { + case IP_OPTIONS: + case IP_RETOPTS: + *mp = m = m_get(M_WAIT, MT_SOOPTS); + if (inp->inp_options) { + m->m_len = inp->inp_options->m_len; + bcopy(mtod(inp->inp_options, caddr_t), + mtod(m, caddr_t), (unsigned)m->m_len); + } else + m->m_len = 0; + break; + + case IP_TOS: + case IP_TTL: + case IP_RECVOPTS: + case IP_RECVRETOPTS: + case IP_RECVDSTADDR: + *mp = m = m_get(M_WAIT, MT_SOOPTS); + m->m_len = sizeof(int); + switch (optname) { + + case IP_TOS: + optval = inp->inp_ip.ip_tos; + break; + + case IP_TTL: + optval = inp->inp_ip.ip_ttl; + break; + +#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) + + case IP_RECVOPTS: + optval = OPTBIT(INP_RECVOPTS); + break; + + case IP_RECVRETOPTS: + optval = OPTBIT(INP_RECVRETOPTS); + break; + + case IP_RECVDSTADDR: + optval = OPTBIT(INP_RECVDSTADDR); + break; + } + *mtod(m, int *) = optval; + break; + + case IP_MULTICAST_IF: + case IP_MULTICAST_TTL: + case IP_MULTICAST_LOOP: + case IP_ADD_MEMBERSHIP: + case IP_DROP_MEMBERSHIP: + error = ip_getmoptions(optname, inp->inp_moptions, mp); + break; + + default: + error = ENOPROTOOPT; + break; + } + break; + } + return (error); +} + +/* + * Set up IP options in pcb for insertion in output packets. + * Store in mbuf with pointer in pcbopt, adding pseudo-option + * with destination address if source routed. + */ +int +#ifdef notyet +ip_pcbopts(optname, pcbopt, m) + int optname; +#else +ip_pcbopts(pcbopt, m) +#endif + struct mbuf **pcbopt; + register struct mbuf *m; +{ + register cnt, optlen; + register u_char *cp; + u_char opt; + + /* turn off any old options */ + if (*pcbopt) + (void)m_free(*pcbopt); + *pcbopt = 0; + if (m == (struct mbuf *)0 || m->m_len == 0) { + /* + * Only turning off any previous options. + */ + if (m) + (void)m_free(m); + return (0); + } + +#ifndef vax + if (m->m_len % sizeof(long)) + goto bad; +#endif + /* + * IP first-hop destination address will be stored before + * actual options; move other options back + * and clear it when none present. + */ + if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) + goto bad; + cnt = m->m_len; + m->m_len += sizeof(struct in_addr); + cp = mtod(m, u_char *) + sizeof(struct in_addr); + ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); + bzero(mtod(m, caddr_t), sizeof(struct in_addr)); + + for (; cnt > 0; cnt -= optlen, cp += optlen) { + opt = cp[IPOPT_OPTVAL]; + if (opt == IPOPT_EOL) + break; + if (opt == IPOPT_NOP) + optlen = 1; + else { + optlen = cp[IPOPT_OLEN]; + if (optlen <= IPOPT_OLEN || optlen > cnt) + goto bad; + } + switch (opt) { + + default: + break; + + case IPOPT_LSRR: + case IPOPT_SSRR: + /* + * user process specifies route as: + * ->A->B->C->D + * D must be our final destination (but we can't + * check that since we may not have connected yet). + * A is first hop destination, which doesn't appear in + * actual IP option, but is stored before the options. + */ + if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) + goto bad; + m->m_len -= sizeof(struct in_addr); + cnt -= sizeof(struct in_addr); + optlen -= sizeof(struct in_addr); + cp[IPOPT_OLEN] = optlen; + /* + * Move first hop before start of options. + */ + bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), + sizeof(struct in_addr)); + /* + * Then copy rest of options back + * to close up the deleted entry. + */ + ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + + sizeof(struct in_addr)), + (caddr_t)&cp[IPOPT_OFFSET+1], + (unsigned)cnt + sizeof(struct in_addr)); + break; + } + } + if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) + goto bad; + *pcbopt = m; + return (0); + +bad: + (void)m_free(m); + return (EINVAL); +} + +/* + * Set the IP multicast options in response to user setsockopt(). + */ +int +ip_setmoptions(optname, imop, m) + int optname; + struct ip_moptions **imop; + struct mbuf *m; +{ + register int error = 0; + u_char loop; + register int i; + struct in_addr addr; + register struct ip_mreq *mreq; + register struct ifnet *ifp; + register struct ip_moptions *imo = *imop; + struct route ro; + register struct sockaddr_in *dst; + + if (imo == NULL) { + /* + * No multicast option buffer attached to the pcb; + * allocate one and initialize to default values. + */ + imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS, + M_WAITOK); + + if (imo == NULL) + return (ENOBUFS); + *imop = imo; + imo->imo_multicast_ifp = NULL; + imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; + imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; + imo->imo_num_memberships = 0; + } + + switch (optname) { + + case IP_MULTICAST_IF: + /* + * Select the interface for outgoing multicast packets. + */ + if (m == NULL || m->m_len != sizeof(struct in_addr)) { + error = EINVAL; + break; + } + addr = *(mtod(m, struct in_addr *)); + /* + * INADDR_ANY is used to remove a previous selection. + * When no interface is selected, a default one is + * chosen every time a multicast packet is sent. + */ + if (addr.s_addr == INADDR_ANY) { + imo->imo_multicast_ifp = NULL; + break; + } + /* + * The selected interface is identified by its local + * IP address. Find the interface and confirm that + * it supports multicasting. + */ + INADDR_TO_IFP(addr, ifp); + if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { + error = EADDRNOTAVAIL; + break; + } + imo->imo_multicast_ifp = ifp; + break; + + case IP_MULTICAST_TTL: + /* + * Set the IP time-to-live for outgoing multicast packets. + */ + if (m == NULL || m->m_len != 1) { + error = EINVAL; + break; + } + imo->imo_multicast_ttl = *(mtod(m, u_char *)); + break; + + case IP_MULTICAST_LOOP: + /* + * Set the loopback flag for outgoing multicast packets. + * Must be zero or one. + */ + if (m == NULL || m->m_len != 1 || + (loop = *(mtod(m, u_char *))) > 1) { + error = EINVAL; + break; + } + imo->imo_multicast_loop = loop; + break; + + case IP_ADD_MEMBERSHIP: + /* + * Add a multicast group membership. + * Group must be a valid IP multicast address. + */ + if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { + error = EINVAL; + break; + } + mreq = mtod(m, struct ip_mreq *); + if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) { + error = EINVAL; + break; + } + /* + * If no interface address was provided, use the interface of + * the route to the given multicast address. + */ + if (mreq->imr_interface.s_addr == INADDR_ANY) { + ro.ro_rt = NULL; + dst = (struct sockaddr_in *)&ro.ro_dst; + dst->sin_len = sizeof(*dst); + dst->sin_family = AF_INET; + dst->sin_addr = mreq->imr_multiaddr; + rtalloc(&ro); + if (ro.ro_rt == NULL) { + error = EADDRNOTAVAIL; + break; + } + ifp = ro.ro_rt->rt_ifp; + rtfree(ro.ro_rt); + } + else { + INADDR_TO_IFP(mreq->imr_interface, ifp); + } + /* + * See if we found an interface, and confirm that it + * supports multicast. + */ + if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { + error = EADDRNOTAVAIL; + break; + } + /* + * See if the membership already exists or if all the + * membership slots are full. + */ + for (i = 0; i < imo->imo_num_memberships; ++i) { + if (imo->imo_membership[i]->inm_ifp == ifp && + imo->imo_membership[i]->inm_addr.s_addr + == mreq->imr_multiaddr.s_addr) + break; + } + if (i < imo->imo_num_memberships) { + error = EADDRINUSE; + break; + } + if (i == IP_MAX_MEMBERSHIPS) { + error = ETOOMANYREFS; + break; + } + /* + * Everything looks good; add a new record to the multicast + * address list for the given interface. + */ + if ((imo->imo_membership[i] = + in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { + error = ENOBUFS; + break; + } + ++imo->imo_num_memberships; + break; + + case IP_DROP_MEMBERSHIP: + /* + * Drop a multicast group membership. + * Group must be a valid IP multicast address. + */ + if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { + error = EINVAL; + break; + } + mreq = mtod(m, struct ip_mreq *); + if (!IN_MULTICAST(ntohl(mreq->imr_multiaddr.s_addr))) { + error = EINVAL; + break; + } + /* + * If an interface address was specified, get a pointer + * to its ifnet structure. + */ + if (mreq->imr_interface.s_addr == INADDR_ANY) + ifp = NULL; + else { + INADDR_TO_IFP(mreq->imr_interface, ifp); + if (ifp == NULL) { + error = EADDRNOTAVAIL; + break; + } + } + /* + * Find the membership in the membership array. + */ + for (i = 0; i < imo->imo_num_memberships; ++i) { + if ((ifp == NULL || + imo->imo_membership[i]->inm_ifp == ifp) && + imo->imo_membership[i]->inm_addr.s_addr == + mreq->imr_multiaddr.s_addr) + break; + } + if (i == imo->imo_num_memberships) { + error = EADDRNOTAVAIL; + break; + } + /* + * Give up the multicast address record to which the + * membership points. + */ + in_delmulti(imo->imo_membership[i]); + /* + * Remove the gap in the membership array. + */ + for (++i; i < imo->imo_num_memberships; ++i) + imo->imo_membership[i-1] = imo->imo_membership[i]; + --imo->imo_num_memberships; + break; + + default: + error = EOPNOTSUPP; + break; + } + + /* + * If all options have default values, no need to keep the mbuf. + */ + if (imo->imo_multicast_ifp == NULL && + imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && + imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && + imo->imo_num_memberships == 0) { + free(*imop, M_IPMOPTS); + *imop = NULL; + } + + return (error); +} + +/* + * Return the IP multicast options in response to user getsockopt(). + */ +int +ip_getmoptions(optname, imo, mp) + int optname; + register struct ip_moptions *imo; + register struct mbuf **mp; +{ + u_char *ttl; + u_char *loop; + struct in_addr *addr; + struct in_ifaddr *ia; + + *mp = m_get(M_WAIT, MT_SOOPTS); + + switch (optname) { + + case IP_MULTICAST_IF: + addr = mtod(*mp, struct in_addr *); + (*mp)->m_len = sizeof(struct in_addr); + if (imo == NULL || imo->imo_multicast_ifp == NULL) + addr->s_addr = INADDR_ANY; + else { + IFP_TO_IA(imo->imo_multicast_ifp, ia); + addr->s_addr = (ia == NULL) ? INADDR_ANY + : IA_SIN(ia)->sin_addr.s_addr; + } + return (0); + + case IP_MULTICAST_TTL: + ttl = mtod(*mp, u_char *); + (*mp)->m_len = 1; + *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL + : imo->imo_multicast_ttl; + return (0); + + case IP_MULTICAST_LOOP: + loop = mtod(*mp, u_char *); + (*mp)->m_len = 1; + *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP + : imo->imo_multicast_loop; + return (0); + + default: + return (EOPNOTSUPP); + } +} + +/* + * Discard the IP multicast options. + */ +void +ip_freemoptions(imo) + register struct ip_moptions *imo; +{ + register int i; + + if (imo != NULL) { + for (i = 0; i < imo->imo_num_memberships; ++i) + in_delmulti(imo->imo_membership[i]); + free(imo, M_IPMOPTS); + } +} + +/* + * Routine called from ip_output() to loop back a copy of an IP multicast + * packet to the input queue of a specified interface. Note that this + * calls the output routine of the loopback "driver", but with an interface + * pointer that might NOT be &loif -- easier than replicating that code here. + */ +static void +ip_mloopback(ifp, m, dst) + struct ifnet *ifp; + register struct mbuf *m; + register struct sockaddr_in *dst; +{ + register struct ip *ip; + struct mbuf *copym; + + copym = m_copy(m, 0, M_COPYALL); + if (copym != NULL) { + /* + * We don't bother to fragment if the IP length is greater + * than the interface's MTU. Can this possibly matter? + */ + ip = mtod(copym, struct ip *); + ip->ip_len = htons((u_short)ip->ip_len); + ip->ip_off = htons((u_short)ip->ip_off); + ip->ip_sum = 0; + ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); + (void) looutput(ifp, copym, (struct sockaddr *)dst, NULL); + } +} |
