diff options
Diffstat (limited to 'sys/netinet/ip_carp.c')
| -rw-r--r-- | sys/netinet/ip_carp.c | 2172 |
1 files changed, 2172 insertions, 0 deletions
diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c new file mode 100644 index 0000000..eaff4f6 --- /dev/null +++ b/sys/netinet/ip_carp.c @@ -0,0 +1,2172 @@ +/*- + * Copyright (c) 2002 Michael Shalayeff. + * Copyright (c) 2003 Ryan McBride. + * Copyright (c) 2011 Gleb Smirnoff <glebius@FreeBSD.org> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR OR HIS RELATIVES 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 MIND, 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_bpf.h" +#include "opt_inet.h" +#include "opt_inet6.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bus.h> +#include <sys/jail.h> +#include <sys/kernel.h> +#include <sys/limits.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/module.h> +#include <sys/priv.h> +#include <sys/proc.h> +#include <sys/protosw.h> +#include <sys/socket.h> +#include <sys/sockio.h> +#include <sys/sysctl.h> +#include <sys/syslog.h> +#include <sys/taskqueue.h> + +#include <net/ethernet.h> +#include <net/fddi.h> +#include <net/if.h> +#include <net/if_dl.h> +#include <net/if_llatbl.h> +#include <net/if_types.h> +#include <net/iso88025.h> +#include <net/route.h> +#include <net/vnet.h> + +#if defined(INET) || defined(INET6) +#include <netinet/in.h> +#include <netinet/in_var.h> +#include <netinet/ip_carp.h> +#include <netinet/ip.h> +#include <machine/in_cksum.h> +#endif +#ifdef INET +#include <netinet/ip_var.h> +#include <netinet/if_ether.h> +#endif + +#ifdef INET6 +#include <netinet/icmp6.h> +#include <netinet/ip6.h> +#include <netinet6/ip6protosw.h> +#include <netinet6/in6_var.h> +#include <netinet6/ip6_var.h> +#include <netinet6/scope6_var.h> +#include <netinet6/nd6.h> +#endif + +#include <crypto/sha1.h> + +static MALLOC_DEFINE(M_CARP, "CARP", "CARP addresses"); + +struct carp_softc { + struct ifnet *sc_carpdev; /* Pointer to parent ifnet. */ + struct ifaddr **sc_ifas; /* Our ifaddrs. */ + struct sockaddr_dl sc_addr; /* Our link level address. */ + struct callout sc_ad_tmo; /* Advertising timeout. */ +#ifdef INET + struct callout sc_md_tmo; /* Master down timeout. */ +#endif +#ifdef INET6 + struct callout sc_md6_tmo; /* XXX: Master down timeout. */ +#endif + struct mtx sc_mtx; + + int sc_vhid; + int sc_advskew; + int sc_advbase; + + int sc_naddrs; + int sc_naddrs6; + int sc_ifasiz; + enum { INIT = 0, BACKUP, MASTER } sc_state; + int sc_suppress; + int sc_sendad_errors; +#define CARP_SENDAD_MAX_ERRORS 3 + int sc_sendad_success; +#define CARP_SENDAD_MIN_SUCCESS 3 + + int sc_init_counter; + uint64_t sc_counter; + + /* authentication */ +#define CARP_HMAC_PAD 64 + unsigned char sc_key[CARP_KEY_LEN]; + unsigned char sc_pad[CARP_HMAC_PAD]; + SHA1_CTX sc_sha1; + + TAILQ_ENTRY(carp_softc) sc_list; /* On the carp_if list. */ + LIST_ENTRY(carp_softc) sc_next; /* On the global list. */ +}; + +struct carp_if { +#ifdef INET + int cif_naddrs; +#endif +#ifdef INET6 + int cif_naddrs6; +#endif + TAILQ_HEAD(, carp_softc) cif_vrs; +#ifdef INET + struct ip_moptions cif_imo; +#endif +#ifdef INET6 + struct ip6_moptions cif_im6o; +#endif + struct ifnet *cif_ifp; + struct mtx cif_mtx; +}; + +#define CARP_INET 0 +#define CARP_INET6 1 +static int proto_reg[] = {-1, -1}; + +/* + * Brief design of carp(4). + * + * Any carp-capable ifnet may have a list of carp softcs hanging off + * its ifp->if_carp pointer. Each softc represents one unique virtual + * host id, or vhid. The softc has a back pointer to the ifnet. All + * softcs are joined in a global list, which has quite limited use. + * + * Any interface address that takes part in CARP negotiation has a + * pointer to the softc of its vhid, ifa->ifa_carp. That could be either + * AF_INET or AF_INET6 address. + * + * Although, one can get the softc's backpointer to ifnet and traverse + * through its ifp->if_addrhead queue to find all interface addresses + * involved in CARP, we keep a growable array of ifaddr pointers. This + * allows us to avoid grabbing the IF_ADDR_LOCK() in many traversals that + * do calls into the network stack, thus avoiding LORs. + * + * Locking: + * + * Each softc has a lock sc_mtx. It is used to synchronise carp_input_c(), + * callout-driven events and ioctl()s. + * + * To traverse the list of softcs on an ifnet we use CIF_LOCK(), to + * traverse the global list we use the mutex carp_mtx. + * + * Known issues with locking: + * + * - There is no protection for races between two ioctl() requests, + * neither SIOCSVH, nor SIOCAIFADDR & SIOCAIFADDR_IN6. I think that all + * interface ioctl()s should be serialized right in net/if.c. + * - Sending ad, we put the pointer to the softc in an mtag, and no reference + * counting is done on the softc. + * - On module unload we may race (?) with packet processing thread + * dereferencing our function pointers. + */ + +static int carp_allow = 1; /* Accept incoming CARP packets. */ +static int carp_preempt = 0; /* Preempt slower nodes. */ +static int carp_log = 1; /* Log level. */ +static int carp_demotion = 0; /* Global advskew demotion. */ +static int carp_senderr_adj = CARP_MAXSKEW; /* Send error demotion factor */ +static int carp_ifdown_adj = CARP_MAXSKEW; /* Iface down demotion factor */ +static int carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS); + +SYSCTL_NODE(_net_inet, IPPROTO_CARP, carp, CTLFLAG_RW, 0, "CARP"); +SYSCTL_INT(_net_inet_carp, OID_AUTO, allow, CTLFLAG_RW, &carp_allow, 0, + "Accept incoming CARP packets"); +SYSCTL_INT(_net_inet_carp, OID_AUTO, preempt, CTLFLAG_RW, &carp_preempt, 0, + "High-priority backup preemption mode"); +SYSCTL_INT(_net_inet_carp, OID_AUTO, log, CTLFLAG_RW, &carp_log, 0, + "CARP log level"); +SYSCTL_PROC(_net_inet_carp, OID_AUTO, demotion, CTLTYPE_INT|CTLFLAG_RW, + 0, 0, carp_demote_adj_sysctl, "I", + "Adjust demotion factor (skew of advskew)"); +SYSCTL_INT(_net_inet_carp, OID_AUTO, senderr_demotion_factor, CTLFLAG_RW, + &carp_senderr_adj, 0, "Send error demotion factor adjustment"); +SYSCTL_INT(_net_inet_carp, OID_AUTO, ifdown_demotion_factor, CTLFLAG_RW, + &carp_ifdown_adj, 0, "Interface down demotion factor adjustment"); + +static struct carpstats carpstats; +SYSCTL_STRUCT(_net_inet_carp, OID_AUTO, stats, CTLFLAG_RW, &carpstats, + carpstats, "CARP statistics (struct carpstats, netinet/ip_carp.h)"); + +#define CARP_LOCK_INIT(sc) mtx_init(&(sc)->sc_mtx, "carp_softc", \ + NULL, MTX_DEF) +#define CARP_LOCK_DESTROY(sc) mtx_destroy(&(sc)->sc_mtx) +#define CARP_LOCK_ASSERT(sc) mtx_assert(&(sc)->sc_mtx, MA_OWNED) +#define CARP_LOCK(sc) mtx_lock(&(sc)->sc_mtx) +#define CARP_UNLOCK(sc) mtx_unlock(&(sc)->sc_mtx) +#define CIF_LOCK_INIT(cif) mtx_init(&(cif)->cif_mtx, "carp_if", \ + NULL, MTX_DEF) +#define CIF_LOCK_DESTROY(cif) mtx_destroy(&(cif)->cif_mtx) +#define CIF_LOCK_ASSERT(cif) mtx_assert(&(cif)->cif_mtx, MA_OWNED) +#define CIF_LOCK(cif) mtx_lock(&(cif)->cif_mtx) +#define CIF_UNLOCK(cif) mtx_unlock(&(cif)->cif_mtx) +#define CIF_FREE(cif) do { \ + CIF_LOCK_ASSERT(cif); \ + if (TAILQ_EMPTY(&(cif)->cif_vrs)) \ + carp_free_if(cif); \ + else \ + CIF_UNLOCK(cif); \ +} while (0) + +#define CARP_LOG(...) do { \ + if (carp_log > 0) \ + log(LOG_INFO, "carp: " __VA_ARGS__); \ +} while (0) + +#define CARP_DEBUG(...) do { \ + if (carp_log > 1) \ + log(LOG_DEBUG, __VA_ARGS__); \ +} while (0) + +#define IFNET_FOREACH_IFA(ifp, ifa) \ + IF_ADDR_LOCK_ASSERT(ifp); \ + TAILQ_FOREACH((ifa), &(ifp)->if_addrhead, ifa_link) \ + if ((ifa)->ifa_carp != NULL) + +#define CARP_FOREACH_IFA(sc, ifa) \ + CARP_LOCK_ASSERT(sc); \ + for (int _i = 0; \ + _i < (sc)->sc_naddrs + (sc)->sc_naddrs6 && \ + ((ifa) = sc->sc_ifas[_i]) != NULL; \ + ++_i) + +#define IFNET_FOREACH_CARP(ifp, sc) \ + CIF_LOCK_ASSERT(ifp->if_carp); \ + TAILQ_FOREACH((sc), &(ifp)->if_carp->cif_vrs, sc_list) + +#define DEMOTE_ADVSKEW(sc) \ + (((sc)->sc_advskew + carp_demotion > CARP_MAXSKEW) ? \ + CARP_MAXSKEW : ((sc)->sc_advskew + carp_demotion)) + +static void carp_input_c(struct mbuf *, struct carp_header *, sa_family_t); +static struct carp_softc + *carp_alloc(struct ifnet *); +static void carp_detach_locked(struct ifaddr *); +static void carp_destroy(struct carp_softc *); +static struct carp_if + *carp_alloc_if(struct ifnet *); +static void carp_free_if(struct carp_if *); +static void carp_set_state(struct carp_softc *, int); +static void carp_sc_state(struct carp_softc *); +static void carp_setrun(struct carp_softc *, sa_family_t); +static void carp_master_down(void *); +static void carp_master_down_locked(struct carp_softc *); +static void carp_send_ad(void *); +static void carp_send_ad_locked(struct carp_softc *); +static void carp_addroute(struct carp_softc *); +static void carp_ifa_addroute(struct ifaddr *); +static void carp_delroute(struct carp_softc *); +static void carp_ifa_delroute(struct ifaddr *); +static void carp_send_ad_all(void *, int); +static void carp_demote_adj(int, char *); + +static LIST_HEAD(, carp_softc) carp_list; +static struct mtx carp_mtx; +static struct task carp_sendall_task = + TASK_INITIALIZER(0, carp_send_ad_all, NULL); + +static void +carp_hmac_prepare(struct carp_softc *sc) +{ + uint8_t version = CARP_VERSION, type = CARP_ADVERTISEMENT; + uint8_t vhid = sc->sc_vhid & 0xff; + struct ifaddr *ifa; + int i, found; +#ifdef INET + struct in_addr last, cur, in; +#endif +#ifdef INET6 + struct in6_addr last6, cur6, in6; +#endif + + CARP_LOCK_ASSERT(sc); + + /* Compute ipad from key. */ + bzero(sc->sc_pad, sizeof(sc->sc_pad)); + bcopy(sc->sc_key, sc->sc_pad, sizeof(sc->sc_key)); + for (i = 0; i < sizeof(sc->sc_pad); i++) + sc->sc_pad[i] ^= 0x36; + + /* Precompute first part of inner hash. */ + SHA1Init(&sc->sc_sha1); + SHA1Update(&sc->sc_sha1, sc->sc_pad, sizeof(sc->sc_pad)); + SHA1Update(&sc->sc_sha1, (void *)&version, sizeof(version)); + SHA1Update(&sc->sc_sha1, (void *)&type, sizeof(type)); + SHA1Update(&sc->sc_sha1, (void *)&vhid, sizeof(vhid)); +#ifdef INET + cur.s_addr = 0; + do { + found = 0; + last = cur; + cur.s_addr = 0xffffffff; + CARP_FOREACH_IFA(sc, ifa) { + in.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr; + if (ifa->ifa_addr->sa_family == AF_INET && + ntohl(in.s_addr) > ntohl(last.s_addr) && + ntohl(in.s_addr) < ntohl(cur.s_addr)) { + cur.s_addr = in.s_addr; + found++; + } + } + if (found) + SHA1Update(&sc->sc_sha1, (void *)&cur, sizeof(cur)); + } while (found); +#endif /* INET */ +#ifdef INET6 + memset(&cur6, 0, sizeof(cur6)); + do { + found = 0; + last6 = cur6; + memset(&cur6, 0xff, sizeof(cur6)); + CARP_FOREACH_IFA(sc, ifa) { + in6 = ifatoia6(ifa)->ia_addr.sin6_addr; + if (IN6_IS_SCOPE_EMBED(&in6)) + in6.s6_addr16[1] = 0; + if (ifa->ifa_addr->sa_family == AF_INET6 && + memcmp(&in6, &last6, sizeof(in6)) > 0 && + memcmp(&in6, &cur6, sizeof(in6)) < 0) { + cur6 = in6; + found++; + } + } + if (found) + SHA1Update(&sc->sc_sha1, (void *)&cur6, sizeof(cur6)); + } while (found); +#endif /* INET6 */ + + /* convert ipad to opad */ + for (i = 0; i < sizeof(sc->sc_pad); i++) + sc->sc_pad[i] ^= 0x36 ^ 0x5c; +} + +static void +carp_hmac_generate(struct carp_softc *sc, uint32_t counter[2], + unsigned char md[20]) +{ + SHA1_CTX sha1ctx; + + CARP_LOCK_ASSERT(sc); + + /* fetch first half of inner hash */ + bcopy(&sc->sc_sha1, &sha1ctx, sizeof(sha1ctx)); + + SHA1Update(&sha1ctx, (void *)counter, sizeof(sc->sc_counter)); + SHA1Final(md, &sha1ctx); + + /* outer hash */ + SHA1Init(&sha1ctx); + SHA1Update(&sha1ctx, sc->sc_pad, sizeof(sc->sc_pad)); + SHA1Update(&sha1ctx, md, 20); + SHA1Final(md, &sha1ctx); +} + +static int +carp_hmac_verify(struct carp_softc *sc, uint32_t counter[2], + unsigned char md[20]) +{ + unsigned char md2[20]; + + CARP_LOCK_ASSERT(sc); + + carp_hmac_generate(sc, counter, md2); + + return (bcmp(md, md2, sizeof(md2))); +} + +/* + * process input packet. + * we have rearranged checks order compared to the rfc, + * but it seems more efficient this way or not possible otherwise. + */ +#ifdef INET +void +carp_input(struct mbuf *m, int hlen) +{ + struct ip *ip = mtod(m, struct ip *); + struct carp_header *ch; + int iplen, len; + + CARPSTATS_INC(carps_ipackets); + + if (!carp_allow) { + m_freem(m); + return; + } + + /* verify that the IP TTL is 255. */ + if (ip->ip_ttl != CARP_DFLTTL) { + CARPSTATS_INC(carps_badttl); + CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__, + ip->ip_ttl, + m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return; + } + + iplen = ip->ip_hl << 2; + + if (m->m_pkthdr.len < iplen + sizeof(*ch)) { + CARPSTATS_INC(carps_badlen); + CARP_DEBUG("%s: received len %zd < sizeof(struct carp_header) " + "on %s\n", __func__, m->m_len - sizeof(struct ip), + m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return; + } + + if (iplen + sizeof(*ch) < m->m_len) { + if ((m = m_pullup(m, iplen + sizeof(*ch))) == NULL) { + CARPSTATS_INC(carps_hdrops); + CARP_DEBUG("%s: pullup failed\n", __func__); + return; + } + ip = mtod(m, struct ip *); + } + ch = (struct carp_header *)((char *)ip + iplen); + + /* + * verify that the received packet length is + * equal to the CARP header + */ + len = iplen + sizeof(*ch); + if (len > m->m_pkthdr.len) { + CARPSTATS_INC(carps_badlen); + CARP_DEBUG("%s: packet too short %d on %s\n", __func__, + m->m_pkthdr.len, + m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return; + } + + if ((m = m_pullup(m, len)) == NULL) { + CARPSTATS_INC(carps_hdrops); + return; + } + ip = mtod(m, struct ip *); + ch = (struct carp_header *)((char *)ip + iplen); + + /* verify the CARP checksum */ + m->m_data += iplen; + if (in_cksum(m, len - iplen)) { + CARPSTATS_INC(carps_badsum); + CARP_DEBUG("%s: checksum failed on %s\n", __func__, + m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return; + } + m->m_data -= iplen; + + carp_input_c(m, ch, AF_INET); +} +#endif + +#ifdef INET6 +int +carp6_input(struct mbuf **mp, int *offp, int proto) +{ + struct mbuf *m = *mp; + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + struct carp_header *ch; + u_int len; + + CARPSTATS_INC(carps_ipackets6); + + if (!carp_allow) { + m_freem(m); + return (IPPROTO_DONE); + } + + /* check if received on a valid carp interface */ + if (m->m_pkthdr.rcvif->if_carp == NULL) { + CARPSTATS_INC(carps_badif); + CARP_DEBUG("%s: packet received on non-carp interface: %s\n", + __func__, m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return (IPPROTO_DONE); + } + + /* verify that the IP TTL is 255 */ + if (ip6->ip6_hlim != CARP_DFLTTL) { + CARPSTATS_INC(carps_badttl); + CARP_DEBUG("%s: received ttl %d != 255 on %s\n", __func__, + ip6->ip6_hlim, m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return (IPPROTO_DONE); + } + + /* verify that we have a complete carp packet */ + len = m->m_len; + IP6_EXTHDR_GET(ch, struct carp_header *, m, *offp, sizeof(*ch)); + if (ch == NULL) { + CARPSTATS_INC(carps_badlen); + CARP_DEBUG("%s: packet size %u too small\n", __func__, len); + return (IPPROTO_DONE); + } + + + /* verify the CARP checksum */ + m->m_data += *offp; + if (in_cksum(m, sizeof(*ch))) { + CARPSTATS_INC(carps_badsum); + CARP_DEBUG("%s: checksum failed, on %s\n", __func__, + m->m_pkthdr.rcvif->if_xname); + m_freem(m); + return (IPPROTO_DONE); + } + m->m_data -= *offp; + + carp_input_c(m, ch, AF_INET6); + return (IPPROTO_DONE); +} +#endif /* INET6 */ + +static void +carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af) +{ + struct ifnet *ifp = m->m_pkthdr.rcvif; + struct ifaddr *ifa; + struct carp_softc *sc; + uint64_t tmp_counter; + struct timeval sc_tv, ch_tv; + + /* verify that the VHID is valid on the receiving interface */ + IF_ADDR_RLOCK(ifp); + IFNET_FOREACH_IFA(ifp, ifa) + if (ifa->ifa_addr->sa_family == af && + ifa->ifa_carp->sc_vhid == ch->carp_vhid) { + ifa_ref(ifa); + break; + } + IF_ADDR_RUNLOCK(ifp); + + if (ifa == NULL) { + CARPSTATS_INC(carps_badvhid); + m_freem(m); + return; + } + + /* verify the CARP version. */ + if (ch->carp_version != CARP_VERSION) { + CARPSTATS_INC(carps_badver); + CARP_DEBUG("%s: invalid version %d\n", ifp->if_xname, + ch->carp_version); + ifa_free(ifa); + m_freem(m); + return; + } + + sc = ifa->ifa_carp; + CARP_LOCK(sc); + ifa_free(ifa); + + if (carp_hmac_verify(sc, ch->carp_counter, ch->carp_md)) { + CARPSTATS_INC(carps_badauth); + CARP_DEBUG("%s: incorrect hash for VHID %u@%s\n", __func__, + sc->sc_vhid, ifp->if_xname); + goto out; + } + + tmp_counter = ntohl(ch->carp_counter[0]); + tmp_counter = tmp_counter<<32; + tmp_counter += ntohl(ch->carp_counter[1]); + + /* XXX Replay protection goes here */ + + sc->sc_init_counter = 0; + sc->sc_counter = tmp_counter; + + sc_tv.tv_sec = sc->sc_advbase; + sc_tv.tv_usec = DEMOTE_ADVSKEW(sc) * 1000000 / 256; + ch_tv.tv_sec = ch->carp_advbase; + ch_tv.tv_usec = ch->carp_advskew * 1000000 / 256; + + switch (sc->sc_state) { + case INIT: + break; + case MASTER: + /* + * If we receive an advertisement from a master who's going to + * be more frequent than us, go into BACKUP state. + */ + if (timevalcmp(&sc_tv, &ch_tv, >) || + timevalcmp(&sc_tv, &ch_tv, ==)) { + callout_stop(&sc->sc_ad_tmo); + CARP_LOG("VHID %u@%s: MASTER -> BACKUP " + "(more frequent advertisement received)\n", + sc->sc_vhid, + sc->sc_carpdev->if_xname); + carp_set_state(sc, BACKUP); + carp_setrun(sc, 0); + carp_delroute(sc); + } + break; + case BACKUP: + /* + * If we're pre-empting masters who advertise slower than us, + * and this one claims to be slower, treat him as down. + */ + if (carp_preempt && timevalcmp(&sc_tv, &ch_tv, <)) { + CARP_LOG("VHID %u@%s: BACKUP -> MASTER " + "(preempting a slower master)\n", + sc->sc_vhid, + sc->sc_carpdev->if_xname); + carp_master_down_locked(sc); + break; + } + + /* + * If the master is going to advertise at such a low frequency + * that he's guaranteed to time out, we'd might as well just + * treat him as timed out now. + */ + sc_tv.tv_sec = sc->sc_advbase * 3; + if (timevalcmp(&sc_tv, &ch_tv, <)) { + CARP_LOG("VHID %u@%s: BACKUP -> MASTER " + "(master timed out)\n", + sc->sc_vhid, + sc->sc_carpdev->if_xname); + carp_master_down_locked(sc); + break; + } + + /* + * Otherwise, we reset the counter and wait for the next + * advertisement. + */ + carp_setrun(sc, af); + break; + } + +out: + CARP_UNLOCK(sc); + m_freem(m); +} + +static int +carp_prepare_ad(struct mbuf *m, struct carp_softc *sc, struct carp_header *ch) +{ + struct m_tag *mtag; + + if (sc->sc_init_counter) { + /* this could also be seconds since unix epoch */ + sc->sc_counter = arc4random(); + sc->sc_counter = sc->sc_counter << 32; + sc->sc_counter += arc4random(); + } else + sc->sc_counter++; + + ch->carp_counter[0] = htonl((sc->sc_counter>>32)&0xffffffff); + ch->carp_counter[1] = htonl(sc->sc_counter&0xffffffff); + + carp_hmac_generate(sc, ch->carp_counter, ch->carp_md); + + /* Tag packet for carp_output */ + if ((mtag = m_tag_get(PACKET_TAG_CARP, sizeof(struct carp_softc *), + M_NOWAIT)) == NULL) { + m_freem(m); + CARPSTATS_INC(carps_onomem); + return (ENOMEM); + } + bcopy(&sc, mtag + 1, sizeof(sc)); + m_tag_prepend(m, mtag); + + return (0); +} + +/* + * To avoid LORs and possible recursions this function shouldn't + * be called directly, but scheduled via taskqueue. + */ +static void +carp_send_ad_all(void *ctx __unused, int pending __unused) +{ + struct carp_softc *sc; + + mtx_lock(&carp_mtx); + LIST_FOREACH(sc, &carp_list, sc_next) + if (sc->sc_state == MASTER) { + CARP_LOCK(sc); + CURVNET_SET(sc->sc_carpdev->if_vnet); + carp_send_ad_locked(sc); + CURVNET_RESTORE(); + CARP_UNLOCK(sc); + } + mtx_unlock(&carp_mtx); +} + +/* Send a periodic advertisement, executed in callout context. */ +static void +carp_send_ad(void *v) +{ + struct carp_softc *sc = v; + + CARP_LOCK_ASSERT(sc); + CURVNET_SET(sc->sc_carpdev->if_vnet); + carp_send_ad_locked(sc); + CURVNET_RESTORE(); + CARP_UNLOCK(sc); +} + +static void +carp_send_ad_locked(struct carp_softc *sc) +{ + struct carp_header ch; + struct timeval tv; + struct sockaddr sa; + struct ifaddr *ifa; + struct carp_header *ch_ptr; + struct mbuf *m; + int len, advskew; + + CARP_LOCK_ASSERT(sc); + + advskew = DEMOTE_ADVSKEW(sc); + tv.tv_sec = sc->sc_advbase; + tv.tv_usec = advskew * 1000000 / 256; + + ch.carp_version = CARP_VERSION; + ch.carp_type = CARP_ADVERTISEMENT; + ch.carp_vhid = sc->sc_vhid; + ch.carp_advbase = sc->sc_advbase; + ch.carp_advskew = advskew; + ch.carp_authlen = 7; /* XXX DEFINE */ + ch.carp_pad1 = 0; /* must be zero */ + ch.carp_cksum = 0; + + /* XXXGL: OpenBSD picks first ifaddr with needed family. */ + +#ifdef INET + if (sc->sc_naddrs) { + struct ip *ip; + + m = m_gethdr(M_NOWAIT, MT_DATA); + if (m == NULL) { + CARPSTATS_INC(carps_onomem); + goto resched; + } + len = sizeof(*ip) + sizeof(ch); + m->m_pkthdr.len = len; + m->m_pkthdr.rcvif = NULL; + m->m_len = len; + MH_ALIGN(m, m->m_len); + m->m_flags |= M_MCAST; + ip = mtod(m, struct ip *); + ip->ip_v = IPVERSION; + ip->ip_hl = sizeof(*ip) >> 2; + ip->ip_tos = IPTOS_LOWDELAY; + ip->ip_len = htons(len); + ip->ip_id = ip_newid(); + ip->ip_off = htons(IP_DF); + ip->ip_ttl = CARP_DFLTTL; + ip->ip_p = IPPROTO_CARP; + ip->ip_sum = 0; + + bzero(&sa, sizeof(sa)); + sa.sa_family = AF_INET; + ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev); + if (ifa != NULL) { + ip->ip_src.s_addr = + ifatoia(ifa)->ia_addr.sin_addr.s_addr; + ifa_free(ifa); + } else + ip->ip_src.s_addr = 0; + ip->ip_dst.s_addr = htonl(INADDR_CARP_GROUP); + + ch_ptr = (struct carp_header *)(&ip[1]); + bcopy(&ch, ch_ptr, sizeof(ch)); + if (carp_prepare_ad(m, sc, ch_ptr)) + goto resched; + + m->m_data += sizeof(*ip); + ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip)); + m->m_data -= sizeof(*ip); + + CARPSTATS_INC(carps_opackets); + + if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, + &sc->sc_carpdev->if_carp->cif_imo, NULL)) { + if (sc->sc_sendad_errors < INT_MAX) + sc->sc_sendad_errors++; + if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) + carp_demote_adj(carp_senderr_adj, "send error"); + sc->sc_sendad_success = 0; + } else { + if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) { + if (++sc->sc_sendad_success >= + CARP_SENDAD_MIN_SUCCESS) { + carp_demote_adj(-carp_senderr_adj, + "send ok"); + sc->sc_sendad_errors = 0; + } + } else + sc->sc_sendad_errors = 0; + } + } +#endif /* INET */ +#ifdef INET6 + if (sc->sc_naddrs6) { + struct ip6_hdr *ip6; + + m = m_gethdr(M_NOWAIT, MT_DATA); + if (m == NULL) { + CARPSTATS_INC(carps_onomem); + goto resched; + } + len = sizeof(*ip6) + sizeof(ch); + m->m_pkthdr.len = len; + m->m_pkthdr.rcvif = NULL; + m->m_len = len; + MH_ALIGN(m, m->m_len); + m->m_flags |= M_MCAST; + ip6 = mtod(m, struct ip6_hdr *); + bzero(ip6, sizeof(*ip6)); + ip6->ip6_vfc |= IPV6_VERSION; + ip6->ip6_hlim = CARP_DFLTTL; + ip6->ip6_nxt = IPPROTO_CARP; + bzero(&sa, sizeof(sa)); + + /* set the source address */ + sa.sa_family = AF_INET6; + ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev); + if (ifa != NULL) { + bcopy(IFA_IN6(ifa), &ip6->ip6_src, + sizeof(struct in6_addr)); + ifa_free(ifa); + } else + /* This should never happen with IPv6. */ + bzero(&ip6->ip6_src, sizeof(struct in6_addr)); + + /* Set the multicast destination. */ + ip6->ip6_dst.s6_addr16[0] = htons(0xff02); + ip6->ip6_dst.s6_addr8[15] = 0x12; + if (in6_setscope(&ip6->ip6_dst, sc->sc_carpdev, NULL) != 0) { + m_freem(m); + CARP_DEBUG("%s: in6_setscope failed\n", __func__); + goto resched; + } + + ch_ptr = (struct carp_header *)(&ip6[1]); + bcopy(&ch, ch_ptr, sizeof(ch)); + if (carp_prepare_ad(m, sc, ch_ptr)) + goto resched; + + m->m_data += sizeof(*ip6); + ch_ptr->carp_cksum = in_cksum(m, len - sizeof(*ip6)); + m->m_data -= sizeof(*ip6); + + CARPSTATS_INC(carps_opackets6); + + if (ip6_output(m, NULL, NULL, 0, + &sc->sc_carpdev->if_carp->cif_im6o, NULL, NULL)) { + if (sc->sc_sendad_errors < INT_MAX) + sc->sc_sendad_errors++; + if (sc->sc_sendad_errors == CARP_SENDAD_MAX_ERRORS) + carp_demote_adj(carp_senderr_adj, + "send6 error"); + sc->sc_sendad_success = 0; + } else { + if (sc->sc_sendad_errors >= CARP_SENDAD_MAX_ERRORS) { + if (++sc->sc_sendad_success >= + CARP_SENDAD_MIN_SUCCESS) { + carp_demote_adj(-carp_senderr_adj, + "send6 ok"); + sc->sc_sendad_errors = 0; + } + } else + sc->sc_sendad_errors = 0; + } + } +#endif /* INET6 */ + +resched: + callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), carp_send_ad, sc); +} + +static void +carp_addroute(struct carp_softc *sc) +{ + struct ifaddr *ifa; + + CARP_FOREACH_IFA(sc, ifa) + carp_ifa_addroute(ifa); +} + +static void +carp_ifa_addroute(struct ifaddr *ifa) +{ + + switch (ifa->ifa_addr->sa_family) { +#ifdef INET + case AF_INET: + in_addprefix(ifatoia(ifa), RTF_UP); + ifa_add_loopback_route(ifa, + (struct sockaddr *)&ifatoia(ifa)->ia_addr); + break; +#endif +#ifdef INET6 + case AF_INET6: + ifa_add_loopback_route(ifa, + (struct sockaddr *)&ifatoia6(ifa)->ia_addr); + in6_ifaddloop(ifa); + break; +#endif + } +} + +static void +carp_delroute(struct carp_softc *sc) +{ + struct ifaddr *ifa; + + CARP_FOREACH_IFA(sc, ifa) + carp_ifa_delroute(ifa); +} + +static void +carp_ifa_delroute(struct ifaddr *ifa) +{ + + switch (ifa->ifa_addr->sa_family) { +#ifdef INET + case AF_INET: + ifa_del_loopback_route(ifa, + (struct sockaddr *)&ifatoia(ifa)->ia_addr); + in_scrubprefix(ifatoia(ifa), LLE_STATIC); + break; +#endif +#ifdef INET6 + case AF_INET6: + ifa_del_loopback_route(ifa, + (struct sockaddr *)&ifatoia6(ifa)->ia_addr); + in6_ifremloop(ifa); + break; +#endif + } +} + +int +carp_master(struct ifaddr *ifa) +{ + struct carp_softc *sc = ifa->ifa_carp; + + return (sc->sc_state == MASTER); +} + +#ifdef INET +/* + * Broadcast a gratuitous ARP request containing + * the virtual router MAC address for each IP address + * associated with the virtual router. + */ +static void +carp_send_arp(struct carp_softc *sc) +{ + struct ifaddr *ifa; + + CARP_FOREACH_IFA(sc, ifa) + if (ifa->ifa_addr->sa_family == AF_INET) + arp_ifinit2(sc->sc_carpdev, ifa, LLADDR(&sc->sc_addr)); +} + +int +carp_iamatch(struct ifaddr *ifa, uint8_t **enaddr) +{ + struct carp_softc *sc = ifa->ifa_carp; + + if (sc->sc_state == MASTER) { + *enaddr = LLADDR(&sc->sc_addr); + return (1); + } + + return (0); +} +#endif + +#ifdef INET6 +static void +carp_send_na(struct carp_softc *sc) +{ + static struct in6_addr mcast = IN6ADDR_LINKLOCAL_ALLNODES_INIT; + struct ifaddr *ifa; + struct in6_addr *in6; + + CARP_FOREACH_IFA(sc, ifa) { + if (ifa->ifa_addr->sa_family != AF_INET6) + continue; + + in6 = IFA_IN6(ifa); + nd6_na_output(sc->sc_carpdev, &mcast, in6, + ND_NA_FLAG_OVERRIDE, 1, NULL); + DELAY(1000); /* XXX */ + } +} + +/* + * Returns ifa in case it's a carp address and it is MASTER, or if the address + * matches and is not a carp address. Returns NULL otherwise. + */ +struct ifaddr * +carp_iamatch6(struct ifnet *ifp, struct in6_addr *taddr) +{ + struct ifaddr *ifa; + + ifa = NULL; + IF_ADDR_RLOCK(ifp); + TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { + if (ifa->ifa_addr->sa_family != AF_INET6) + continue; + if (!IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) + continue; + if (ifa->ifa_carp && ifa->ifa_carp->sc_state != MASTER) + ifa = NULL; + else + ifa_ref(ifa); + break; + } + IF_ADDR_RUNLOCK(ifp); + + return (ifa); +} + +caddr_t +carp_macmatch6(struct ifnet *ifp, struct mbuf *m, const struct in6_addr *taddr) +{ + struct ifaddr *ifa; + + IF_ADDR_RLOCK(ifp); + IFNET_FOREACH_IFA(ifp, ifa) + if (ifa->ifa_addr->sa_family == AF_INET6 && + IN6_ARE_ADDR_EQUAL(taddr, IFA_IN6(ifa))) { + struct carp_softc *sc = ifa->ifa_carp; + struct m_tag *mtag; + + IF_ADDR_RUNLOCK(ifp); + + mtag = m_tag_get(PACKET_TAG_CARP, + sizeof(struct carp_softc *), M_NOWAIT); + if (mtag == NULL) + /* Better a bit than nothing. */ + return (LLADDR(&sc->sc_addr)); + + bcopy(&sc, mtag + 1, sizeof(sc)); + m_tag_prepend(m, mtag); + + return (LLADDR(&sc->sc_addr)); + } + IF_ADDR_RUNLOCK(ifp); + + return (NULL); +} +#endif /* INET6 */ + +int +carp_forus(struct ifnet *ifp, u_char *dhost) +{ + struct carp_softc *sc; + uint8_t *ena = dhost; + + if (ena[0] || ena[1] || ena[2] != 0x5e || ena[3] || ena[4] != 1) + return (0); + + CIF_LOCK(ifp->if_carp); + IFNET_FOREACH_CARP(ifp, sc) { + CARP_LOCK(sc); + if (sc->sc_state == MASTER && !bcmp(dhost, LLADDR(&sc->sc_addr), + ETHER_ADDR_LEN)) { + CARP_UNLOCK(sc); + CIF_UNLOCK(ifp->if_carp); + return (1); + } + CARP_UNLOCK(sc); + } + CIF_UNLOCK(ifp->if_carp); + + return (0); +} + +/* Master down timeout event, executed in callout context. */ +static void +carp_master_down(void *v) +{ + struct carp_softc *sc = v; + + CARP_LOCK_ASSERT(sc); + + CURVNET_SET(sc->sc_carpdev->if_vnet); + if (sc->sc_state == BACKUP) { + CARP_LOG("VHID %u@%s: BACKUP -> MASTER (master down)\n", + sc->sc_vhid, + sc->sc_carpdev->if_xname); + carp_master_down_locked(sc); + } + CURVNET_RESTORE(); + + CARP_UNLOCK(sc); +} + +static void +carp_master_down_locked(struct carp_softc *sc) +{ + + CARP_LOCK_ASSERT(sc); + + switch (sc->sc_state) { + case BACKUP: + carp_set_state(sc, MASTER); + carp_send_ad_locked(sc); +#ifdef INET + carp_send_arp(sc); +#endif +#ifdef INET6 + carp_send_na(sc); +#endif + carp_setrun(sc, 0); + carp_addroute(sc); + break; + case INIT: + case MASTER: +#ifdef INVARIANTS + panic("carp: VHID %u@%s: master_down event in %s state\n", + sc->sc_vhid, + sc->sc_carpdev->if_xname, + sc->sc_state ? "MASTER" : "INIT"); +#endif + break; + } +} + +/* + * When in backup state, af indicates whether to reset the master down timer + * for v4 or v6. If it's set to zero, reset the ones which are already pending. + */ +static void +carp_setrun(struct carp_softc *sc, sa_family_t af) +{ + struct timeval tv; + + CARP_LOCK_ASSERT(sc); + + if ((sc->sc_carpdev->if_flags & IFF_UP) == 0 || + sc->sc_carpdev->if_link_state != LINK_STATE_UP || + (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0)) + return; + + switch (sc->sc_state) { + case INIT: + CARP_LOG("VHID %u@%s: INIT -> BACKUP\n", + sc->sc_vhid, + sc->sc_carpdev->if_xname); + carp_set_state(sc, BACKUP); + carp_setrun(sc, 0); + break; + case BACKUP: + callout_stop(&sc->sc_ad_tmo); + tv.tv_sec = 3 * sc->sc_advbase; + tv.tv_usec = sc->sc_advskew * 1000000 / 256; + switch (af) { +#ifdef INET + case AF_INET: + callout_reset(&sc->sc_md_tmo, tvtohz(&tv), + carp_master_down, sc); + break; +#endif +#ifdef INET6 + case AF_INET6: + callout_reset(&sc->sc_md6_tmo, tvtohz(&tv), + carp_master_down, sc); + break; +#endif + default: +#ifdef INET + if (sc->sc_naddrs) + callout_reset(&sc->sc_md_tmo, tvtohz(&tv), + carp_master_down, sc); +#endif +#ifdef INET6 + if (sc->sc_naddrs6) + callout_reset(&sc->sc_md6_tmo, tvtohz(&tv), + carp_master_down, sc); +#endif + break; + } + break; + case MASTER: + tv.tv_sec = sc->sc_advbase; + tv.tv_usec = sc->sc_advskew * 1000000 / 256; + callout_reset(&sc->sc_ad_tmo, tvtohz(&tv), + carp_send_ad, sc); + break; + } +} + +/* + * Setup multicast structures. + */ +static int +carp_multicast_setup(struct carp_if *cif, sa_family_t sa) +{ + struct ifnet *ifp = cif->cif_ifp; + int error = 0; + + CIF_LOCK_ASSERT(cif); + + switch (sa) { +#ifdef INET + case AF_INET: + { + struct ip_moptions *imo = &cif->cif_imo; + struct in_addr addr; + + if (imo->imo_membership) + return (0); + + imo->imo_membership = (struct in_multi **)malloc( + (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_CARP, + M_NOWAIT); + if (imo->imo_membership == NULL) + return (ENOMEM); + imo->imo_mfilters = NULL; + imo->imo_max_memberships = IP_MIN_MEMBERSHIPS; + imo->imo_multicast_vif = -1; + + addr.s_addr = htonl(INADDR_CARP_GROUP); + if ((error = in_joingroup(ifp, &addr, NULL, + &imo->imo_membership[0])) != 0) { + free(imo->imo_membership, M_CARP); + break; + } + imo->imo_num_memberships++; + imo->imo_multicast_ifp = ifp; + imo->imo_multicast_ttl = CARP_DFLTTL; + imo->imo_multicast_loop = 0; + break; + } +#endif +#ifdef INET6 + case AF_INET6: + { + struct ip6_moptions *im6o = &cif->cif_im6o; + struct in6_addr in6; + struct in6_multi *in6m; + + if (im6o->im6o_membership) + return (0); + + im6o->im6o_membership = (struct in6_multi **)malloc( + (sizeof(struct in6_multi *) * IPV6_MIN_MEMBERSHIPS), M_CARP, + M_ZERO | M_NOWAIT); + if (im6o->im6o_membership == NULL) + return (ENOMEM); + im6o->im6o_mfilters = NULL; + im6o->im6o_max_memberships = IPV6_MIN_MEMBERSHIPS; + im6o->im6o_multicast_hlim = CARP_DFLTTL; + im6o->im6o_multicast_ifp = ifp; + + /* Join IPv6 CARP multicast group. */ + bzero(&in6, sizeof(in6)); + in6.s6_addr16[0] = htons(0xff02); + in6.s6_addr8[15] = 0x12; + if ((error = in6_setscope(&in6, ifp, NULL)) != 0) { + free(im6o->im6o_membership, M_CARP); + break; + } + in6m = NULL; + if ((error = in6_mc_join(ifp, &in6, NULL, &in6m, 0)) != 0) { + free(im6o->im6o_membership, M_CARP); + break; + } + im6o->im6o_membership[0] = in6m; + im6o->im6o_num_memberships++; + + /* Join solicited multicast address. */ + bzero(&in6, sizeof(in6)); + in6.s6_addr16[0] = htons(0xff02); + in6.s6_addr32[1] = 0; + in6.s6_addr32[2] = htonl(1); + in6.s6_addr32[3] = 0; + in6.s6_addr8[12] = 0xff; + if ((error = in6_setscope(&in6, ifp, NULL)) != 0) { + in6_mc_leave(im6o->im6o_membership[0], NULL); + free(im6o->im6o_membership, M_CARP); + break; + } + in6m = NULL; + if ((error = in6_mc_join(ifp, &in6, NULL, &in6m, 0)) != 0) { + in6_mc_leave(im6o->im6o_membership[0], NULL); + free(im6o->im6o_membership, M_CARP); + break; + } + im6o->im6o_membership[1] = in6m; + im6o->im6o_num_memberships++; + break; + } +#endif + } + + return (error); +} + +/* + * Free multicast structures. + */ +static void +carp_multicast_cleanup(struct carp_if *cif, sa_family_t sa) +{ + + CIF_LOCK_ASSERT(cif); + switch (sa) { +#ifdef INET + case AF_INET: + if (cif->cif_naddrs == 0) { + struct ip_moptions *imo = &cif->cif_imo; + + in_leavegroup(imo->imo_membership[0], NULL); + KASSERT(imo->imo_mfilters == NULL, + ("%s: imo_mfilters != NULL", __func__)); + free(imo->imo_membership, M_CARP); + imo->imo_membership = NULL; + + } + break; +#endif +#ifdef INET6 + case AF_INET6: + if (cif->cif_naddrs6 == 0) { + struct ip6_moptions *im6o = &cif->cif_im6o; + + in6_mc_leave(im6o->im6o_membership[0], NULL); + in6_mc_leave(im6o->im6o_membership[1], NULL); + KASSERT(im6o->im6o_mfilters == NULL, + ("%s: im6o_mfilters != NULL", __func__)); + free(im6o->im6o_membership, M_CARP); + im6o->im6o_membership = NULL; + } + break; +#endif + } +} + +int +carp_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa) +{ + struct m_tag *mtag; + struct carp_softc *sc; + + if (!sa) + return (0); + + switch (sa->sa_family) { +#ifdef INET + case AF_INET: + break; +#endif +#ifdef INET6 + case AF_INET6: + break; +#endif + default: + return (0); + } + + mtag = m_tag_find(m, PACKET_TAG_CARP, NULL); + if (mtag == NULL) + return (0); + + bcopy(mtag + 1, &sc, sizeof(sc)); + + /* Set the source MAC address to the Virtual Router MAC Address. */ + switch (ifp->if_type) { + case IFT_ETHER: + case IFT_BRIDGE: + case IFT_L2VLAN: { + struct ether_header *eh; + + eh = mtod(m, struct ether_header *); + eh->ether_shost[0] = 0; + eh->ether_shost[1] = 0; + eh->ether_shost[2] = 0x5e; + eh->ether_shost[3] = 0; + eh->ether_shost[4] = 1; + eh->ether_shost[5] = sc->sc_vhid; + } + break; + case IFT_FDDI: { + struct fddi_header *fh; + + fh = mtod(m, struct fddi_header *); + fh->fddi_shost[0] = 0; + fh->fddi_shost[1] = 0; + fh->fddi_shost[2] = 0x5e; + fh->fddi_shost[3] = 0; + fh->fddi_shost[4] = 1; + fh->fddi_shost[5] = sc->sc_vhid; + } + break; + case IFT_ISO88025: { + struct iso88025_header *th; + th = mtod(m, struct iso88025_header *); + th->iso88025_shost[0] = 3; + th->iso88025_shost[1] = 0; + th->iso88025_shost[2] = 0x40 >> (sc->sc_vhid - 1); + th->iso88025_shost[3] = 0x40000 >> (sc->sc_vhid - 1); + th->iso88025_shost[4] = 0; + th->iso88025_shost[5] = 0; + } + break; + default: + printf("%s: carp is not supported for the %d interface type\n", + ifp->if_xname, ifp->if_type); + return (EOPNOTSUPP); + } + + return (0); +} + +static struct carp_softc* +carp_alloc(struct ifnet *ifp) +{ + struct carp_softc *sc; + struct carp_if *cif; + + if ((cif = ifp->if_carp) == NULL) { + cif = carp_alloc_if(ifp); + if (cif == NULL) + return (NULL); + } + + sc = malloc(sizeof(*sc), M_CARP, M_WAITOK|M_ZERO); + + sc->sc_advbase = CARP_DFLTINTV; + sc->sc_vhid = -1; /* required setting */ + sc->sc_init_counter = 1; + sc->sc_state = INIT; + + sc->sc_ifasiz = sizeof(struct ifaddr *); + sc->sc_ifas = malloc(sc->sc_ifasiz, M_CARP, M_WAITOK|M_ZERO); + sc->sc_carpdev = ifp; + + CARP_LOCK_INIT(sc); +#ifdef INET + callout_init_mtx(&sc->sc_md_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED); +#endif +#ifdef INET6 + callout_init_mtx(&sc->sc_md6_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED); +#endif + callout_init_mtx(&sc->sc_ad_tmo, &sc->sc_mtx, CALLOUT_RETURNUNLOCKED); + + CIF_LOCK(cif); + TAILQ_INSERT_TAIL(&cif->cif_vrs, sc, sc_list); + CIF_UNLOCK(cif); + + mtx_lock(&carp_mtx); + LIST_INSERT_HEAD(&carp_list, sc, sc_next); + mtx_unlock(&carp_mtx); + + return (sc); +} + +static int +carp_grow_ifas(struct carp_softc *sc) +{ + struct ifaddr **new; + + CARP_LOCK_ASSERT(sc); + + new = malloc(sc->sc_ifasiz * 2, M_CARP, M_NOWAIT|M_ZERO); + if (new == NULL) + return (ENOMEM); + bcopy(sc->sc_ifas, new, sc->sc_ifasiz); + free(sc->sc_ifas, M_CARP); + sc->sc_ifas = new; + sc->sc_ifasiz *= 2; + + return (0); +} + +static void +carp_destroy(struct carp_softc *sc) +{ + struct ifnet *ifp = sc->sc_carpdev; + struct carp_if *cif = ifp->if_carp; + + CIF_LOCK_ASSERT(cif); + + TAILQ_REMOVE(&cif->cif_vrs, sc, sc_list); + + mtx_lock(&carp_mtx); + LIST_REMOVE(sc, sc_next); + mtx_unlock(&carp_mtx); + + CARP_LOCK(sc); + if (sc->sc_suppress) + carp_demote_adj(-carp_ifdown_adj, "vhid removed"); + callout_drain(&sc->sc_ad_tmo); +#ifdef INET + callout_drain(&sc->sc_md_tmo); +#endif +#ifdef INET6 + callout_drain(&sc->sc_md6_tmo); +#endif + CARP_LOCK_DESTROY(sc); + + free(sc->sc_ifas, M_CARP); + free(sc, M_CARP); +} + +static struct carp_if* +carp_alloc_if(struct ifnet *ifp) +{ + struct carp_if *cif; + + cif = malloc(sizeof(*cif), M_CARP, M_WAITOK|M_ZERO); + + if (ifpromisc(ifp, 1) != 0) + goto cleanup; + + CIF_LOCK_INIT(cif); + cif->cif_ifp = ifp; + TAILQ_INIT(&cif->cif_vrs); + + IF_ADDR_WLOCK(ifp); + ifp->if_carp = cif; + if_ref(ifp); + IF_ADDR_WUNLOCK(ifp); + + return (cif); + +cleanup: + free(cif, M_CARP); + + return (NULL); +} + +static void +carp_free_if(struct carp_if *cif) +{ + struct ifnet *ifp = cif->cif_ifp; + + CIF_LOCK_ASSERT(cif); + KASSERT(TAILQ_EMPTY(&cif->cif_vrs), ("%s: softc list not empty", + __func__)); + + IF_ADDR_WLOCK(ifp); + ifp->if_carp = NULL; + if_rele(ifp); + IF_ADDR_WUNLOCK(ifp); + + CIF_LOCK_DESTROY(cif); + + ifpromisc(ifp, 0); + + free(cif, M_CARP); +} + +static void +carp_carprcp(struct carpreq *carpr, struct carp_softc *sc, int priv) +{ + + CARP_LOCK(sc); + carpr->carpr_state = sc->sc_state; + carpr->carpr_vhid = sc->sc_vhid; + carpr->carpr_advbase = sc->sc_advbase; + carpr->carpr_advskew = sc->sc_advskew; + if (priv) + bcopy(sc->sc_key, carpr->carpr_key, sizeof(carpr->carpr_key)); + else + bzero(carpr->carpr_key, sizeof(carpr->carpr_key)); + CARP_UNLOCK(sc); +} + +int +carp_ioctl(struct ifreq *ifr, u_long cmd, struct thread *td) +{ + struct carpreq carpr; + struct ifnet *ifp; + struct carp_softc *sc = NULL; + int error = 0, locked = 0; + + if ((error = copyin(ifr->ifr_data, &carpr, sizeof carpr))) + return (error); + + ifp = ifunit_ref(ifr->ifr_name); + if (ifp == NULL) + return (ENXIO); + + switch (ifp->if_type) { + case IFT_ETHER: + case IFT_L2VLAN: + case IFT_BRIDGE: + case IFT_FDDI: + case IFT_ISO88025: + break; + default: + error = EOPNOTSUPP; + goto out; + } + + if ((ifp->if_flags & IFF_MULTICAST) == 0) { + error = EADDRNOTAVAIL; + goto out; + } + + switch (cmd) { + case SIOCSVH: + if ((error = priv_check(td, PRIV_NETINET_CARP))) + break; + if (carpr.carpr_vhid <= 0 || carpr.carpr_vhid > CARP_MAXVHID || + carpr.carpr_advbase < 0 || carpr.carpr_advskew < 0) { + error = EINVAL; + break; + } + + if (ifp->if_carp) { + CIF_LOCK(ifp->if_carp); + IFNET_FOREACH_CARP(ifp, sc) + if (sc->sc_vhid == carpr.carpr_vhid) + break; + CIF_UNLOCK(ifp->if_carp); + } + if (sc == NULL) { + sc = carp_alloc(ifp); + if (sc == NULL) { + error = EINVAL; /* XXX: ifpromisc failed */ + break; + } + + CARP_LOCK(sc); + sc->sc_vhid = carpr.carpr_vhid; + LLADDR(&sc->sc_addr)[0] = 0; + LLADDR(&sc->sc_addr)[1] = 0; + LLADDR(&sc->sc_addr)[2] = 0x5e; + LLADDR(&sc->sc_addr)[3] = 0; + LLADDR(&sc->sc_addr)[4] = 1; + LLADDR(&sc->sc_addr)[5] = sc->sc_vhid; + } else + CARP_LOCK(sc); + locked = 1; + if (carpr.carpr_advbase > 0) { + if (carpr.carpr_advbase > 255 || + carpr.carpr_advbase < CARP_DFLTINTV) { + error = EINVAL; + break; + } + sc->sc_advbase = carpr.carpr_advbase; + } + if (carpr.carpr_advskew > 0) { + if (carpr.carpr_advskew >= 255) { + error = EINVAL; + break; + } + sc->sc_advskew = carpr.carpr_advskew; + } + if (carpr.carpr_key[0] != '\0') { + bcopy(carpr.carpr_key, sc->sc_key, sizeof(sc->sc_key)); + carp_hmac_prepare(sc); + } + if (sc->sc_state != INIT && + carpr.carpr_state != sc->sc_state) { + switch (carpr.carpr_state) { + case BACKUP: + callout_stop(&sc->sc_ad_tmo); + carp_set_state(sc, BACKUP); + carp_setrun(sc, 0); + carp_delroute(sc); + break; + case MASTER: + carp_master_down_locked(sc); + break; + default: + break; + } + } + break; + + case SIOCGVH: + { + int priveleged; + + if (carpr.carpr_vhid < 0 || carpr.carpr_vhid > CARP_MAXVHID) { + error = EINVAL; + break; + } + if (carpr.carpr_count < 1) { + error = EMSGSIZE; + break; + } + if (ifp->if_carp == NULL) { + error = ENOENT; + break; + } + + priveleged = (priv_check(td, PRIV_NETINET_CARP) == 0); + if (carpr.carpr_vhid != 0) { + CIF_LOCK(ifp->if_carp); + IFNET_FOREACH_CARP(ifp, sc) + if (sc->sc_vhid == carpr.carpr_vhid) + break; + CIF_UNLOCK(ifp->if_carp); + if (sc == NULL) { + error = ENOENT; + break; + } + carp_carprcp(&carpr, sc, priveleged); + error = copyout(&carpr, ifr->ifr_data, sizeof(carpr)); + } else { + int i, count; + + count = 0; + CIF_LOCK(ifp->if_carp); + IFNET_FOREACH_CARP(ifp, sc) + count++; + + if (count > carpr.carpr_count) { + CIF_UNLOCK(ifp->if_carp); + error = EMSGSIZE; + break; + } + + i = 0; + IFNET_FOREACH_CARP(ifp, sc) { + carp_carprcp(&carpr, sc, priveleged); + carpr.carpr_count = count; + error = copyout(&carpr, ifr->ifr_data + + (i * sizeof(carpr)), sizeof(carpr)); + if (error) { + CIF_UNLOCK(ifp->if_carp); + break; + } + i++; + } + CIF_UNLOCK(ifp->if_carp); + } + break; + } + default: + error = EINVAL; + } + +out: + if (locked) + CARP_UNLOCK(sc); + if_rele(ifp); + + return (error); +} + +static int +carp_get_vhid(struct ifaddr *ifa) +{ + + if (ifa == NULL || ifa->ifa_carp == NULL) + return (0); + + return (ifa->ifa_carp->sc_vhid); +} + +int +carp_attach(struct ifaddr *ifa, int vhid) +{ + struct ifnet *ifp = ifa->ifa_ifp; + struct carp_if *cif = ifp->if_carp; + struct carp_softc *sc; + int index, error; + + if (ifp->if_carp == NULL) + return (ENOPROTOOPT); + + switch (ifa->ifa_addr->sa_family) { +#ifdef INET + case AF_INET: +#endif +#ifdef INET6 + case AF_INET6: +#endif + break; + default: + return (EPROTOTYPE); + } + + CIF_LOCK(cif); + IFNET_FOREACH_CARP(ifp, sc) + if (sc->sc_vhid == vhid) + break; + if (sc == NULL) { + CIF_UNLOCK(cif); + return (ENOENT); + } + + if (ifa->ifa_carp) { + if (ifa->ifa_carp->sc_vhid != vhid) + carp_detach_locked(ifa); + else { + CIF_UNLOCK(cif); + return (0); + } + } + + error = carp_multicast_setup(cif, ifa->ifa_addr->sa_family); + if (error) { + CIF_FREE(cif); + return (error); + } + + CARP_LOCK(sc); + index = sc->sc_naddrs + sc->sc_naddrs6 + 1; + if (index > sc->sc_ifasiz / sizeof(struct ifaddr *)) + if ((error = carp_grow_ifas(sc)) != 0) { + carp_multicast_cleanup(cif, + ifa->ifa_addr->sa_family); + CARP_UNLOCK(sc); + CIF_FREE(cif); + return (error); + } + + switch (ifa->ifa_addr->sa_family) { +#ifdef INET + case AF_INET: + cif->cif_naddrs++; + sc->sc_naddrs++; + break; +#endif +#ifdef INET6 + case AF_INET6: + cif->cif_naddrs6++; + sc->sc_naddrs6++; + break; +#endif + } + + ifa_ref(ifa); + sc->sc_ifas[index - 1] = ifa; + ifa->ifa_carp = sc; + + carp_hmac_prepare(sc); + carp_sc_state(sc); + + CARP_UNLOCK(sc); + CIF_UNLOCK(cif); + + return (0); +} + +void +carp_detach(struct ifaddr *ifa) +{ + struct ifnet *ifp = ifa->ifa_ifp; + struct carp_if *cif = ifp->if_carp; + + CIF_LOCK(cif); + carp_detach_locked(ifa); + CIF_FREE(cif); +} + +static void +carp_detach_locked(struct ifaddr *ifa) +{ + struct ifnet *ifp = ifa->ifa_ifp; + struct carp_if *cif = ifp->if_carp; + struct carp_softc *sc = ifa->ifa_carp; + int i, index; + + KASSERT(sc != NULL, ("%s: %p not attached", __func__, ifa)); + + CIF_LOCK_ASSERT(cif); + CARP_LOCK(sc); + + /* Shift array. */ + index = sc->sc_naddrs + sc->sc_naddrs6; + for (i = 0; i < index; i++) + if (sc->sc_ifas[i] == ifa) + break; + KASSERT(i < index, ("%s: %p no backref", __func__, ifa)); + for (; i < index - 1; i++) + sc->sc_ifas[i] = sc->sc_ifas[i+1]; + sc->sc_ifas[index - 1] = NULL; + + switch (ifa->ifa_addr->sa_family) { +#ifdef INET + case AF_INET: + cif->cif_naddrs--; + sc->sc_naddrs--; + break; +#endif +#ifdef INET6 + case AF_INET6: + cif->cif_naddrs6--; + sc->sc_naddrs6--; + break; +#endif + } + + carp_ifa_delroute(ifa); + carp_multicast_cleanup(cif, ifa->ifa_addr->sa_family); + + ifa->ifa_carp = NULL; + ifa_free(ifa); + + carp_hmac_prepare(sc); + carp_sc_state(sc); + + if (sc->sc_naddrs == 0 && sc->sc_naddrs6 == 0) { + CARP_UNLOCK(sc); + carp_destroy(sc); + } else + CARP_UNLOCK(sc); +} + +static void +carp_set_state(struct carp_softc *sc, int state) +{ + + CARP_LOCK_ASSERT(sc); + + if (sc->sc_state != state) { + const char *carp_states[] = { CARP_STATES }; + char subsys[IFNAMSIZ+5]; + + sc->sc_state = state; + + snprintf(subsys, IFNAMSIZ+5, "%u@%s", sc->sc_vhid, + sc->sc_carpdev->if_xname); + devctl_notify("CARP", subsys, carp_states[state], NULL); + } +} + +static void +carp_linkstate(struct ifnet *ifp) +{ + struct carp_softc *sc; + + CIF_LOCK(ifp->if_carp); + IFNET_FOREACH_CARP(ifp, sc) { + CARP_LOCK(sc); + carp_sc_state(sc); + CARP_UNLOCK(sc); + } + CIF_UNLOCK(ifp->if_carp); +} + +static void +carp_sc_state(struct carp_softc *sc) +{ + + CARP_LOCK_ASSERT(sc); + + if (sc->sc_carpdev->if_link_state != LINK_STATE_UP || + !(sc->sc_carpdev->if_flags & IFF_UP)) { + callout_stop(&sc->sc_ad_tmo); +#ifdef INET + callout_stop(&sc->sc_md_tmo); +#endif +#ifdef INET6 + callout_stop(&sc->sc_md6_tmo); +#endif + carp_set_state(sc, INIT); + carp_setrun(sc, 0); + if (!sc->sc_suppress) + carp_demote_adj(carp_ifdown_adj, "interface down"); + sc->sc_suppress = 1; + } else { + carp_set_state(sc, INIT); + carp_setrun(sc, 0); + if (sc->sc_suppress) + carp_demote_adj(-carp_ifdown_adj, "interface up"); + sc->sc_suppress = 0; + } +} + +static void +carp_demote_adj(int adj, char *reason) +{ + atomic_add_int(&carp_demotion, adj); + CARP_LOG("demoted by %d to %d (%s)\n", adj, carp_demotion, reason); + taskqueue_enqueue(taskqueue_swi, &carp_sendall_task); +} + +static int +carp_demote_adj_sysctl(SYSCTL_HANDLER_ARGS) +{ + int new, error; + + new = carp_demotion; + error = sysctl_handle_int(oidp, &new, 0, req); + if (error || !req->newptr) + return (error); + + carp_demote_adj(new, "sysctl"); + + return (0); +} + +#ifdef INET +extern struct domain inetdomain; +static struct protosw in_carp_protosw = { + .pr_type = SOCK_RAW, + .pr_domain = &inetdomain, + .pr_protocol = IPPROTO_CARP, + .pr_flags = PR_ATOMIC|PR_ADDR, + .pr_input = carp_input, + .pr_output = (pr_output_t *)rip_output, + .pr_ctloutput = rip_ctloutput, + .pr_usrreqs = &rip_usrreqs +}; +#endif + +#ifdef INET6 +extern struct domain inet6domain; +static struct ip6protosw in6_carp_protosw = { + .pr_type = SOCK_RAW, + .pr_domain = &inet6domain, + .pr_protocol = IPPROTO_CARP, + .pr_flags = PR_ATOMIC|PR_ADDR, + .pr_input = carp6_input, + .pr_output = rip6_output, + .pr_ctloutput = rip6_ctloutput, + .pr_usrreqs = &rip6_usrreqs +}; +#endif + +static void +carp_mod_cleanup(void) +{ + +#ifdef INET + if (proto_reg[CARP_INET] == 0) { + (void)ipproto_unregister(IPPROTO_CARP); + pf_proto_unregister(PF_INET, IPPROTO_CARP, SOCK_RAW); + proto_reg[CARP_INET] = -1; + } + carp_iamatch_p = NULL; +#endif +#ifdef INET6 + if (proto_reg[CARP_INET6] == 0) { + (void)ip6proto_unregister(IPPROTO_CARP); + pf_proto_unregister(PF_INET6, IPPROTO_CARP, SOCK_RAW); + proto_reg[CARP_INET6] = -1; + } + carp_iamatch6_p = NULL; + carp_macmatch6_p = NULL; +#endif + carp_ioctl_p = NULL; + carp_attach_p = NULL; + carp_detach_p = NULL; + carp_get_vhid_p = NULL; + carp_linkstate_p = NULL; + carp_forus_p = NULL; + carp_output_p = NULL; + carp_demote_adj_p = NULL; + carp_master_p = NULL; + mtx_unlock(&carp_mtx); + taskqueue_drain(taskqueue_swi, &carp_sendall_task); + mtx_destroy(&carp_mtx); +} + +static int +carp_mod_load(void) +{ + int err; + + mtx_init(&carp_mtx, "carp_mtx", NULL, MTX_DEF); + LIST_INIT(&carp_list); + carp_get_vhid_p = carp_get_vhid; + carp_forus_p = carp_forus; + carp_output_p = carp_output; + carp_linkstate_p = carp_linkstate; + carp_ioctl_p = carp_ioctl; + carp_attach_p = carp_attach; + carp_detach_p = carp_detach; + carp_demote_adj_p = carp_demote_adj; + carp_master_p = carp_master; +#ifdef INET6 + carp_iamatch6_p = carp_iamatch6; + carp_macmatch6_p = carp_macmatch6; + proto_reg[CARP_INET6] = pf_proto_register(PF_INET6, + (struct protosw *)&in6_carp_protosw); + if (proto_reg[CARP_INET6]) { + printf("carp: error %d attaching to PF_INET6\n", + proto_reg[CARP_INET6]); + carp_mod_cleanup(); + return (proto_reg[CARP_INET6]); + } + err = ip6proto_register(IPPROTO_CARP); + if (err) { + printf("carp: error %d registering with INET6\n", err); + carp_mod_cleanup(); + return (err); + } +#endif +#ifdef INET + carp_iamatch_p = carp_iamatch; + proto_reg[CARP_INET] = pf_proto_register(PF_INET, &in_carp_protosw); + if (proto_reg[CARP_INET]) { + printf("carp: error %d attaching to PF_INET\n", + proto_reg[CARP_INET]); + carp_mod_cleanup(); + return (proto_reg[CARP_INET]); + } + err = ipproto_register(IPPROTO_CARP); + if (err) { + printf("carp: error %d registering with INET\n", err); + carp_mod_cleanup(); + return (err); + } +#endif + return (0); +} + +static int +carp_modevent(module_t mod, int type, void *data) +{ + switch (type) { + case MOD_LOAD: + return carp_mod_load(); + /* NOTREACHED */ + case MOD_UNLOAD: + mtx_lock(&carp_mtx); + if (LIST_EMPTY(&carp_list)) + carp_mod_cleanup(); + else { + mtx_unlock(&carp_mtx); + return (EBUSY); + } + break; + + default: + return (EINVAL); + } + + return (0); +} + +static moduledata_t carp_mod = { + "carp", + carp_modevent, + 0 +}; + +DECLARE_MODULE(carp, carp_mod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); |
