diff options
Diffstat (limited to 'sys/netipsec/ipsec_output.c')
| -rw-r--r-- | sys/netipsec/ipsec_output.c | 737 |
1 files changed, 737 insertions, 0 deletions
diff --git a/sys/netipsec/ipsec_output.c b/sys/netipsec/ipsec_output.c new file mode 100644 index 0000000..836e17b --- /dev/null +++ b/sys/netipsec/ipsec_output.c @@ -0,0 +1,737 @@ +/* $FreeBSD$ */ +/* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */ + +/* + * IPsec output processing. + */ +#include "opt_inet.h" +#include "opt_inet6.h" +#include "opt_ipsec.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/mbuf.h> +#include <sys/domain.h> +#include <sys/protosw.h> +#include <sys/socket.h> +#include <sys/errno.h> +#include <sys/syslog.h> + +#include <net/if.h> +#include <net/route.h> + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#include <netinet/ip_var.h> +#include <netinet/in_var.h> +#include <netinet/ip_ecn.h> +#ifdef INET6 +#include <netinet6/ip6_ecn.h> +#endif + +#include <netinet/ip6.h> +#ifdef INET6 +#include <netinet6/ip6_var.h> +#endif +#include <netinet/in_pcb.h> +#ifdef INET6 +#include <netinet/icmp6.h> +#endif + +#include <netipsec/ipsec.h> +#ifdef INET6 +#include <netipsec/ipsec6.h> +#endif +#include <netipsec/ah_var.h> +#include <netipsec/esp_var.h> +#include <netipsec/ipcomp_var.h> + +#include <netipsec/xform.h> + +#include <netipsec/key.h> +#include <netipsec/keydb.h> +#include <netipsec/key_debug.h> + +#include <machine/in_cksum.h> + +int +ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr) +{ + struct tdb_ident *tdbi; + struct m_tag *mtag; + struct secasvar *sav; + struct secasindex *saidx; + int error; + +#if 0 + SPLASSERT(net, "ipsec_process_done"); +#endif + + KASSERT(m != NULL, ("ipsec_process_done: null mbuf")); + KASSERT(isr != NULL, ("ipsec_process_done: null ISR")); + sav = isr->sav; + KASSERT(sav != NULL, ("ipsec_process_done: null SA")); + KASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH")); + + saidx = &sav->sah->saidx; + switch (saidx->dst.sa.sa_family) { +#ifdef INET + case AF_INET: + /* Fix the header length, for AH processing. */ + mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); + break; +#endif /* INET */ +#ifdef INET6 + case AF_INET6: + /* Fix the header length, for AH processing. */ + if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) { + error = ENXIO; + goto bad; + } + if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) { + /* No jumbogram support. */ + error = ENXIO; /*?*/ + goto bad; + } + mtod(m, struct ip6_hdr *)->ip6_plen = + htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); + break; +#endif /* INET6 */ + default: + DPRINTF(("ipsec_process_done: unknown protocol family %u\n", + saidx->dst.sa.sa_family)); + error = ENXIO; + goto bad; + } + + /* + * Add a record of what we've done or what needs to be done to the + * packet. + */ + mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, + sizeof(struct tdb_ident), M_NOWAIT); + if (mtag == NULL) { + DPRINTF(("ipsec_process_done: could not get packet tag\n")); + error = ENOMEM; + goto bad; + } + + tdbi = (struct tdb_ident *)(mtag + 1); + tdbi->dst = saidx->dst; + tdbi->proto = saidx->proto; + tdbi->spi = sav->spi; + m_tag_prepend(m, mtag); + + /* + * If there's another (bundled) SA to apply, do so. + * Note that this puts a burden on the kernel stack size. + * If this is a problem we'll need to introduce a queue + * to set the packet on so we can unwind the stack before + * doing further processing. + */ + if (isr->next) { + newipsecstat.ips_out_bundlesa++; + return ipsec4_process_packet(m, isr->next, 0, 0); + } + + /* + * We're done with IPsec processing, transmit the packet using the + * appropriate network protocol (IP or IPv6). SPD lookup will be + * performed again there. + */ + switch (saidx->dst.sa.sa_family) { +#ifdef INET + struct ip *ip; + case AF_INET: + ip = mtod(m, struct ip *); + ip->ip_len = ntohs(ip->ip_len); + ip->ip_off = ntohs(ip->ip_off); + + return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL); +#endif /* INET */ +#ifdef INET6 + case AF_INET6: + /* + * We don't need massage, IPv6 header fields are always in + * net endian. + */ + return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); +#endif /* INET6 */ + } + panic("ipsec_process_done"); +bad: + m_freem(m); + KEY_FREESAV(&sav); + return (error); +} + +static struct ipsecrequest * +ipsec_nextisr( + struct mbuf *m, + struct ipsecrequest *isr, + int af, + struct secasindex *saidx, + int *error +) +{ +#define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \ + isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++) + struct secasvar *sav; + +#if 0 + SPLASSERT(net, "ipsec_nextisr"); +#endif + KASSERT(af == AF_INET || af == AF_INET6, + ("ipsec_nextisr: invalid address family %u", af)); +again: + /* + * Craft SA index to search for proper SA. Note that + * we only fillin unspecified SA peers for transport + * mode; for tunnel mode they must already be filled in. + */ + *saidx = isr->saidx; + if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) { + /* Fillin unspecified SA peers only for transport mode */ + if (af == AF_INET) { + struct sockaddr_in *sin; + struct ip *ip = mtod(m, struct ip *); + + if (saidx->src.sa.sa_len == 0) { + sin = &saidx->src.sin; + sin->sin_len = sizeof(*sin); + sin->sin_family = AF_INET; + sin->sin_port = IPSEC_PORT_ANY; + sin->sin_addr = ip->ip_src; + } + if (saidx->dst.sa.sa_len == 0) { + sin = &saidx->dst.sin; + sin->sin_len = sizeof(*sin); + sin->sin_family = AF_INET; + sin->sin_port = IPSEC_PORT_ANY; + sin->sin_addr = ip->ip_dst; + } + } else { + struct sockaddr_in6 *sin6; + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + + if (saidx->src.sin6.sin6_len == 0) { + sin6 = (struct sockaddr_in6 *)&saidx->src; + sin6->sin6_len = sizeof(*sin6); + sin6->sin6_family = AF_INET6; + sin6->sin6_port = IPSEC_PORT_ANY; + sin6->sin6_addr = ip6->ip6_src; + if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) { + /* fix scope id for comparing SPD */ + sin6->sin6_addr.s6_addr16[1] = 0; + sin6->sin6_scope_id = + ntohs(ip6->ip6_src.s6_addr16[1]); + } + } + if (saidx->dst.sin6.sin6_len == 0) { + sin6 = (struct sockaddr_in6 *)&saidx->dst; + sin6->sin6_len = sizeof(*sin6); + sin6->sin6_family = AF_INET6; + sin6->sin6_port = IPSEC_PORT_ANY; + sin6->sin6_addr = ip6->ip6_dst; + if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) { + /* fix scope id for comparing SPD */ + sin6->sin6_addr.s6_addr16[1] = 0; + sin6->sin6_scope_id = + ntohs(ip6->ip6_dst.s6_addr16[1]); + } + } + } + } + + /* + * Lookup SA and validate it. + */ + *error = key_checkrequest(isr, saidx); + if (*error != 0) { + /* + * IPsec processing is required, but no SA found. + * I assume that key_acquire() had been called + * to get/establish the SA. Here I discard + * this packet because it is responsibility for + * upper layer to retransmit the packet. + */ + newipsecstat.ips_out_nosa++; + goto bad; + } + sav = isr->sav; + if (sav == NULL) { /* XXX valid return */ + KASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE, + ("ipsec_nextisr: no SA found, but required; level %u", + ipsec_get_reqlevel(isr))); + isr = isr->next; + if (isr == NULL) { + /*XXXstatistic??*/ + *error = EINVAL; /*XXX*/ + return isr; + } + goto again; + } + + /* + * Check system global policy controls. + */ + if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) || + (isr->saidx.proto == IPPROTO_AH && !ah_enable) || + (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) { + DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due" + " to policy (check your sysctls)\n")); + IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops, + ipcompstat.ipcomps_pdrops); + *error = EHOSTUNREACH; + goto bad; + } + + /* + * Sanity check the SA contents for the caller + * before they invoke the xform output method. + */ + if (sav->tdb_xform == NULL) { + DPRINTF(("ipsec_nextisr: no transform for SA\n")); + IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform, + ipcompstat.ipcomps_noxform); + *error = EHOSTUNREACH; + goto bad; + } + return isr; +bad: + KASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code")); + return NULL; +#undef IPSEC_OSTAT +} + +#ifdef INET +/* + * IPsec output logic for IPv4. + */ +int +ipsec4_process_packet( + struct mbuf *m, + struct ipsecrequest *isr, + int flags, + int tunalready) +{ + struct secasindex saidx; + struct secasvar *sav; + struct ip *ip; + int s, error, i, off; + + KASSERT(m != NULL, ("ipsec4_process_packet: null mbuf")); + KASSERT(isr != NULL, ("ipsec4_process_packet: null isr")); + + s = splnet(); /* insure SA contents don't change */ + + isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error); + if (isr == NULL) + goto bad; + + sav = isr->sav; + if (!tunalready) { + union sockaddr_union *dst = &sav->sah->saidx.dst; + int setdf; + + /* + * Collect IP_DF state from the outer header. + */ + if (dst->sa.sa_family == AF_INET) { + if (m->m_len < sizeof (struct ip) && + (m = m_pullup(m, sizeof (struct ip))) == NULL) { + error = ENOBUFS; + goto bad; + } + ip = mtod(m, struct ip *); + /* Honor system-wide control of how to handle IP_DF */ + switch (ip4_ipsec_dfbit) { + case 0: /* clear in outer header */ + case 1: /* set in outer header */ + setdf = ip4_ipsec_dfbit; + break; + default: /* propagate to outer header */ + setdf = ntohs(ip->ip_off & IP_DF); + break; + } + } else { + ip = NULL; /* keep compiler happy */ + setdf = 0; + } + /* Do the appropriate encapsulation, if necessary */ + if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */ + dst->sa.sa_family != AF_INET || /* PF mismatch */ +#if 0 + (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */ + sav->tdb_xform->xf_type == XF_IP4 || /* ditto */ +#endif + (dst->sa.sa_family == AF_INET && /* Proxy */ + dst->sin.sin_addr.s_addr != INADDR_ANY && + dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) { + struct mbuf *mp; + + /* Fix IPv4 header checksum and length */ + if (m->m_len < sizeof (struct ip) && + (m = m_pullup(m, sizeof (struct ip))) == NULL) { + error = ENOBUFS; + goto bad; + } + ip = mtod(m, struct ip *); + ip->ip_len = htons(m->m_pkthdr.len); + ip->ip_sum = 0; +#ifdef _IP_VHL + if (ip->ip_vhl == IP_VHL_BORING) + ip->ip_sum = in_cksum_hdr(ip); + else + ip->ip_sum = in_cksum(m, + _IP_VHL_HL(ip->ip_vhl) << 2); +#else + ip->ip_sum = in_cksum(m, ip->ip_hl << 2); +#endif + + /* Encapsulate the packet */ + error = ipip_output(m, isr, &mp, 0, 0); + if (mp == NULL && !error) { + /* Should never happen. */ + DPRINTF(("ipsec4_process_packet: ipip_output " + "returns no mbuf and no error!")); + error = EFAULT; + } + if (error) { + if (mp) + m_freem(mp); + goto bad; + } + m = mp, mp = NULL; + /* + * ipip_output clears IP_DF in the new header. If + * we need to propagate IP_DF from the outer header, + * then we have to do it here. + * + * XXX shouldn't assume what ipip_output does. + */ + if (dst->sa.sa_family == AF_INET && setdf) { + if (m->m_len < sizeof (struct ip) && + (m = m_pullup(m, sizeof (struct ip))) == NULL) { + error = ENOBUFS; + goto bad; + } + ip = mtod(m, struct ip *); + ip->ip_off = ntohs(ip->ip_off); + ip->ip_off |= IP_DF; + ip->ip_off = htons(ip->ip_off); + } + } + } + + /* + * Dispatch to the appropriate IPsec transform logic. The + * packet will be returned for transmission after crypto + * processing, etc. are completed. For encapsulation we + * bypass this call because of the explicit call done above + * (necessary to deal with IP_DF handling for IPv4). + * + * NB: m & sav are ``passed to caller'' who's reponsible for + * for reclaiming their resources. + */ + if (sav->tdb_xform->xf_type != XF_IP4) { + ip = mtod(m, struct ip *); + i = ip->ip_hl << 2; + off = offsetof(struct ip, ip_p); + error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off); + } else { + error = ipsec_process_done(m, isr); + } + splx(s); + return error; +bad: + splx(s); + if (m) + m_freem(m); + return error; +} +#endif + +#ifdef INET6 +/* + * Chop IP6 header from the payload. + */ +static struct mbuf * +ipsec6_splithdr(struct mbuf *m) +{ + struct mbuf *mh; + struct ip6_hdr *ip6; + int hlen; + + KASSERT(m->m_len >= sizeof (struct ip6_hdr), + ("ipsec6_splithdr: first mbuf too short, len %u", m->m_len)); + ip6 = mtod(m, struct ip6_hdr *); + hlen = sizeof(struct ip6_hdr); + if (m->m_len > hlen) { + MGETHDR(mh, M_DONTWAIT, MT_HEADER); + if (!mh) { + m_freem(m); + return NULL; + } + M_COPY_PKTHDR(mh, m); + MH_ALIGN(mh, hlen); + m->m_len -= hlen; + m->m_data += hlen; + mh->m_next = m; + m = mh; + m->m_len = hlen; + bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen); + } else if (m->m_len < hlen) { + m = m_pullup(m, hlen); + if (!m) + return NULL; + } + return m; +} + +/* + * IPsec output logic for IPv6, transport mode. + */ +int +ipsec6_output_trans( + struct ipsec_output_state *state, + u_char *nexthdrp, + struct mbuf *mprev, + struct secpolicy *sp, + int flags, + int *tun) +{ + struct ipsecrequest *isr; + struct secasindex saidx; + int error = 0; + struct mbuf *m; + + KASSERT(state != NULL, ("ipsec6_output: null state")); + KASSERT(state->m != NULL, ("ipsec6_output: null m")); + KASSERT(nexthdrp != NULL, ("ipsec6_output: null nexthdrp")); + KASSERT(mprev != NULL, ("ipsec6_output: null mprev")); + KASSERT(sp != NULL, ("ipsec6_output: null sp")); + KASSERT(tun != NULL, ("ipsec6_output: null tun")); + + KEYDEBUG(KEYDEBUG_IPSEC_DATA, + printf("ipsec6_output_trans: applyed SP\n"); + kdebug_secpolicy(sp)); + + isr = sp->req; + if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { + /* the rest will be handled by ipsec6_output_tunnel() */ + *tun = 1; /* need tunnel-mode processing */ + return 0; + } + + *tun = 0; + m = state->m; + + isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); + if (isr == NULL) { +#ifdef notdef + /* XXX should notification be done for all errors ? */ + /* + * Notify the fact that the packet is discarded + * to ourselves. I believe this is better than + * just silently discarding. (jinmei@kame.net) + * XXX: should we restrict the error to TCP packets? + * XXX: should we directly notify sockets via + * pfctlinputs? + */ + icmp6_error(m, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_ADMIN, 0); + m = NULL; /* NB: icmp6_error frees mbuf */ +#endif + goto bad; + } + + return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL, + sizeof (struct ip6_hdr), + offsetof(struct ip6_hdr, ip6_nxt)); +bad: + if (m) + m_freem(m); + state->m = NULL; + return error; +} + +static int +ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav) +{ + struct ip6_hdr *oip6; + struct ip6_hdr *ip6; + size_t plen; + + /* can't tunnel between different AFs */ + if (sav->sah->saidx.src.sa.sa_family != AF_INET6 || + sav->sah->saidx.dst.sa.sa_family != AF_INET6) { + m_freem(m); + return EINVAL; + } + KASSERT(m->m_len != sizeof (struct ip6_hdr), + ("ipsec6_encapsulate: mbuf wrong size; len %u", m->m_len)); + + + /* + * grow the mbuf to accomodate the new IPv6 header. + */ + plen = m->m_pkthdr.len; + if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) { + struct mbuf *n; + MGET(n, M_DONTWAIT, MT_DATA); + if (!n) { + m_freem(m); + return ENOBUFS; + } + n->m_len = sizeof(struct ip6_hdr); + n->m_next = m->m_next; + m->m_next = n; + m->m_pkthdr.len += sizeof(struct ip6_hdr); + oip6 = mtod(n, struct ip6_hdr *); + } else { + m->m_next->m_len += sizeof(struct ip6_hdr); + m->m_next->m_data -= sizeof(struct ip6_hdr); + m->m_pkthdr.len += sizeof(struct ip6_hdr); + oip6 = mtod(m->m_next, struct ip6_hdr *); + } + ip6 = mtod(m, struct ip6_hdr *); + ovbcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr)); + + /* Fake link-local scope-class addresses */ + if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src)) + oip6->ip6_src.s6_addr16[1] = 0; + if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst)) + oip6->ip6_dst.s6_addr16[1] = 0; + + /* construct new IPv6 header. see RFC 2401 5.1.2.2 */ + /* ECN consideration. */ + ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow); + if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr)) + ip6->ip6_plen = htons(plen); + else { + /* ip6->ip6_plen will be updated in ip6_output() */ + } + ip6->ip6_nxt = IPPROTO_IPV6; + sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src; + sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst; + ip6->ip6_hlim = IPV6_DEFHLIM; + + /* XXX Should ip6_src be updated later ? */ + + return 0; +} + +/* + * IPsec output logic for IPv6, tunnel mode. + */ +int +ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags) +{ + struct ip6_hdr *ip6; + struct ipsecrequest *isr; + struct secasindex saidx; + int error; + struct sockaddr_in6* dst6; + struct mbuf *m; + + KASSERT(state != NULL, ("ipsec6_output: null state")); + KASSERT(state->m != NULL, ("ipsec6_output: null m")); + KASSERT(sp != NULL, ("ipsec6_output: null sp")); + + KEYDEBUG(KEYDEBUG_IPSEC_DATA, + printf("ipsec6_output_tunnel: applyed SP\n"); + kdebug_secpolicy(sp)); + + m = state->m; + /* + * transport mode ipsec (before the 1st tunnel mode) is already + * processed by ipsec6_output_trans(). + */ + for (isr = sp->req; isr; isr = isr->next) { + if (isr->saidx.mode == IPSEC_MODE_TUNNEL) + break; + } + isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error); + if (isr == NULL) + goto bad; + + /* + * There may be the case that SA status will be changed when + * we are refering to one. So calling splsoftnet(). + */ + if (isr->saidx.mode == IPSEC_MODE_TUNNEL) { + /* + * build IPsec tunnel. + */ + /* XXX should be processed with other familiy */ + if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) { + ipseclog((LOG_ERR, "ipsec6_output_tunnel: " + "family mismatched between inner and outer, spi=%u\n", + ntohl(isr->sav->spi))); + newipsecstat.ips_out_inval++; + error = EAFNOSUPPORT; + goto bad; + } + + m = ipsec6_splithdr(m); + if (!m) { + newipsecstat.ips_out_nomem++; + error = ENOMEM; + goto bad; + } + error = ipsec6_encapsulate(m, isr->sav); + if (error) { + m = NULL; + goto bad; + } + ip6 = mtod(m, struct ip6_hdr *); + + state->ro = &isr->sav->sah->sa_route; + state->dst = (struct sockaddr *)&state->ro->ro_dst; + dst6 = (struct sockaddr_in6 *)state->dst; + if (state->ro->ro_rt + && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0 + || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) { + RTFREE(state->ro->ro_rt); + state->ro->ro_rt = NULL; + } + if (state->ro->ro_rt == 0) { + bzero(dst6, sizeof(*dst6)); + dst6->sin6_family = AF_INET6; + dst6->sin6_len = sizeof(*dst6); + dst6->sin6_addr = ip6->ip6_dst; + rtalloc(state->ro); + } + if (state->ro->ro_rt == 0) { + ip6stat.ip6s_noroute++; + newipsecstat.ips_out_noroute++; + error = EHOSTUNREACH; + goto bad; + } + + /* adjust state->dst if tunnel endpoint is offlink */ + if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) { + state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway; + dst6 = (struct sockaddr_in6 *)state->dst; + } + } + + m = ipsec6_splithdr(m); + if (!m) { + newipsecstat.ips_out_nomem++; + error = ENOMEM; + goto bad; + } + ip6 = mtod(m, struct ip6_hdr *); + return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL, + sizeof (struct ip6_hdr), + offsetof(struct ip6_hdr, ip6_nxt)); +bad: + if (m) + m_freem(m); + state->m = NULL; + return error; +} +#endif /*INET6*/ |
