X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/37acaef1c378dac38ce880b037891a7e3af93193..refs/heads/master:/site.c diff --git a/site.c b/site.c index 39520dd..d0dd909 100644 --- a/site.c +++ b/site.c @@ -321,21 +321,21 @@ struct site { uint32_t local_capabilities; int32_t setup_retries; /* How many times to send setup packets */ int32_t setup_retry_interval; /* Initial timeout for setup packets */ - int32_t wait_timeout; /* How long to wait if setup unsuccessful */ + int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */ int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */ int32_t key_lifetime; /* How long a key lasts once set up */ int32_t key_renegotiate_time; /* If we see traffic (or a keepalive) after this time, initiate a new key exchange */ - bool_t setup_priority; /* Do we have precedence if both sites emit - message 1 simultaneously? */ + bool_t our_name_later; /* our name > peer name */ uint32_t log_events; /* runtime information */ uint32_t state; uint64_t now; /* Most recently seen time */ bool_t allow_send_prod; + bool_t msg1_crossed_logged; int resolving_count; int resolving_n_results_all; int resolving_n_results_stored; @@ -470,14 +470,15 @@ static bool_t current_valid(struct site *st) } #define DEFINE_CALL_TRANSFORM(fwdrev) \ -static int call_transform_##fwdrev(struct site *st, \ +static transform_apply_return \ +call_transform_##fwdrev(struct site *st, \ struct transform_inst_if *transform, \ struct buffer_if *buf, \ const char **errmsg) \ { \ if (!is_transform_valid(transform)) { \ *errmsg="transform not set up"; \ - return 1; \ + return transform_apply_err; \ } \ return transform->fwdrev(transform->st,buf,errmsg); \ } @@ -534,6 +535,16 @@ struct msg { char *sig; }; +static int32_t wait_timeout(struct site *st) { + int32_t t = st->wait_timeout_mean; + int8_t factor; + if (t < INT_MAX/2) { + st->random->generate(st->random->st,sizeof(factor),&factor); + t += (t / 256) * factor; + } + return t; +} + static _Bool set_new_transform(struct site *st, char *pk) { _Bool ok; @@ -556,7 +567,7 @@ static _Bool set_new_transform(struct site *st, char *pk) struct transform_if *generator=st->chosen_transform; struct transform_inst_if *generated=generator->create(generator->st); ok = generated->setkey(generated->st,st->sharedsecret, - st->sharedsecretlen,st->setup_priority); + st->sharedsecretlen,st->our_name_later); dispose_transform(&st->new_transform); if (!ok) return False; @@ -756,7 +767,7 @@ static bool_t check_msg(struct site *st, uint32_t type, struct msg *m, return False; } if (type==LABEL_MSG2) return True; - if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) { + if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) { *error="wrong remotely-generated nonce"; return False; } @@ -1029,8 +1040,9 @@ static void create_msg6(struct site *st, struct transform_inst_if *transform, /* Give the netlink code an opportunity to put its own stuff in the message (configuration information, etc.) */ buf_prepend_uint32(&st->buffer,LABEL_MSG6); - int problem = call_transform_forwards(st,transform, - &st->buffer,&transform_err); + transform_apply_return problem = + call_transform_forwards(st,transform, + &st->buffer,&transform_err); assert(!problem); buf_prepend_uint32(&st->buffer,LABEL_MSG6); buf_prepend_uint32(&st->buffer,st->index); @@ -1070,12 +1082,13 @@ static bool_t process_msg6(struct site *st, struct buffer_if *msg6, return True; } -static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0, +static transform_apply_return +decrypt_msg0(struct site *st, struct buffer_if *msg0, const struct comm_addr *src) { cstring_t transform_err, auxkey_err, newkey_err="n/a"; struct msg0 m; - uint32_t problem; + transform_apply_return problem; if (!unpick_msg0(st,msg0,&m)) return False; @@ -1088,15 +1101,15 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0, if (!st->auxiliary_is_new) delete_one_key(st,&st->auxiliary_key, "peer has used new key","auxiliary key",LOG_SEC); - return True; + return 0; } - if (problem==2) - goto skew; + if (transform_apply_return_badseq(problem)) + goto badseq; buffer_copy(msg0, &st->scratch); problem = call_transform_reverse(st,st->auxiliary_key.transform, msg0,&auxkey_err); - if (problem==0) { + if (!problem) { slog(st,LOG_DROP,"processing packet which uses auxiliary key"); if (st->auxiliary_is_new) { /* We previously timed out in state SENTMSG5 but it turns @@ -1113,10 +1126,10 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0, st->auxiliary_is_new=0; st->renegotiate_key_time=st->auxiliary_renegotiate_key_time; } - return True; + return 0; } - if (problem==2) - goto skew; + if (transform_apply_return_badseq(problem)) + goto badseq; if (st->state==SITE_SENTMSG5) { buffer_copy(msg0, &st->scratch); @@ -1129,20 +1142,21 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0, BUF_FREE(&st->buffer); st->timeout=0; activate_new_key(st); - return True; /* do process the data in this packet */ + return 0; /* do process the data in this packet */ } - if (problem==2) - goto skew; + if (transform_apply_return_badseq(problem)) + goto badseq; } slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)", transform_err,auxkey_err,newkey_err); initiate_key_setup(st,"incoming message would not decrypt",0); send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt"); - return False; + assert(problem); + return problem; - skew: - slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err); + badseq: + slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err); assert(problem); return problem; } @@ -1151,8 +1165,18 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0, const struct comm_addr *src) { uint32_t type; - - if (!decrypt_msg0(st,msg0,src)) + transform_apply_return problem; + + problem = decrypt_msg0(st,msg0,src); + if (problem==transform_apply_seqdupe) { + /* We recently received another copy of this packet, maybe due + * to polypath. That's not a problem; indeed, for the + * purposes of transport address management it is a success. + * But we don't want to process the packet. */ + transport_data_msgok(st,src); + return False; + } + if (problem) return False; CHECK_AVAIL(msg0,4); @@ -1339,7 +1363,7 @@ static void decrement_resolving_count(struct site *st, int by) } else if (st->local_mobile) { /* Not very good. We should queue (another) renegotiation * so that we can update the peer address. */ - st->key_renegotiate_time=st->now+st->wait_timeout; + st->key_renegotiate_time=st->now+wait_timeout(st); } else { slog(st,LOG_SETUP_INIT,"resolution failed: " " continuing to use source address of peer's packets"); @@ -1452,7 +1476,8 @@ static void set_link_quality(struct site *st) static void enter_state_run(struct site *st) { - slog(st,LOG_STATE,"entering state RUN"); + slog(st,LOG_STATE,"entering state RUN%s", + current_valid(st) ? " (keyed)" : " (unkeyed)"); st->state=SITE_RUN; st->timeout=0; @@ -1525,6 +1550,7 @@ static bool_t enter_new_state(struct site *st, uint32_t next) case SITE_SENTMSG1: state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE); gen=generate_msg1; + st->msg1_crossed_logged = False; break; case SITE_SENTMSG2: state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE || @@ -1613,7 +1639,7 @@ static bool_t send_msg7(struct site *st, cstring_t reason) static void enter_state_wait(struct site *st) { slog(st,LOG_STATE,"entering state WAIT"); - st->timeout=st->now+st->wait_timeout; + st->timeout=st->now+wait_timeout(st); st->state=SITE_WAIT; set_link_quality(st); BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */ @@ -1754,6 +1780,35 @@ static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in, && name_matches(&m->local,st->localname); } +static bool_t we_have_priority(struct site *st, const struct msg *m) { + if (st->local_capabilities & m->remote_capabilities & + CAPAB_PRIORITY_MOBILE) { + if (st->local_mobile) return True; + if (st-> peer_mobile) return False; + } + return st->our_name_later; +} + +static bool_t setup_late_msg_ok(struct site *st, + const struct buffer_if *buf_in, + uint32_t msgtype, + const struct comm_addr *source) { + /* For setup packets which seem from their type like they are + * late. Maybe they came via a different path. All we do is make + * a note of the sending address, iff they look like they are part + * of the current key setup attempt. */ + struct msg m; + if (!named_for_us(st,buf_in,msgtype,&m)) + /* named_for_us calls unpick_msg which gets the nonces */ + return False; + if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) || + !consttime_memeq(m.nL,st->localN, NONCELEN)) + /* spoof ? from stale run ? who knows */ + return False; + transport_setup_msgok(st,source); + return True; +} + /* This function is called by the communication device to deliver packets from our peers. It should return True if the packet is recognised as being for @@ -1795,13 +1850,14 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, /* We've just sent a message 1! They may have crossed on the wire. If we have priority then we ignore the incoming one, otherwise we process it as usual. */ - if (st->setup_priority) { + if (we_have_priority(st,&named_msg)) { BUF_FREE(buf); - slog(st,LOG_DUMP,"crossed msg1s; we are higher " - "priority => ignore incoming msg1"); + if (!st->msg1_crossed_logged++) + slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher " + "priority => ignore incoming msg1"); return True; } else { - slog(st,LOG_DUMP,"crossed msg1s; we are lower " + slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower " "priority => use incoming msg1"); if (process_msg1(st,buf,source,&named_msg)) { BUF_FREE(&st->buffer); /* Free our old message 1 */ @@ -1814,9 +1870,21 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, BUF_FREE(buf); return True; } + } else if (st->state==SITE_SENTMSG2 || + st->state==SITE_SENTMSG4) { + if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) { + /* We are ahead in the protocol, but that msg1 had the + * peer's nonce so presumably it is from this key + * exchange run, via a slower route */ + transport_setup_msgok(st,source); + } else { + slog(st,LOG_UNEXPECTED,"competing incoming message 1"); + } + BUF_FREE(buf); + return True; } /* The message 1 was received at an unexpected stage of the - key setup. XXX POLICY - what do we do? */ + key setup. Well, they lost the race. */ slog(st,LOG_UNEXPECTED,"unexpected incoming message 1"); BUF_FREE(buf); return True; @@ -1861,6 +1929,10 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, case LABEL_MSG2: /* Setup packet: expected only in state SENTMSG1 */ if (st->state!=SITE_SENTMSG1) { + if ((st->state==SITE_SENTMSG3 || + st->state==SITE_SENTMSG5) && + setup_late_msg_ok(st,buf,msgtype,source)) + break; slog(st,LOG_UNEXPECTED,"unexpected MSG2"); } else if (process_msg2(st,buf,source)) { transport_setup_msgok(st,source); @@ -1873,6 +1945,9 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, case LABEL_MSG3BIS: /* Setup packet: expected only in state SENTMSG2 */ if (st->state!=SITE_SENTMSG2) { + if ((st->state==SITE_SENTMSG4) && + setup_late_msg_ok(st,buf,msgtype,source)) + break; slog(st,LOG_UNEXPECTED,"unexpected MSG3"); } else if (process_msg3(st,buf,source,msgtype)) { transport_setup_msgok(st,source); @@ -1884,6 +1959,9 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, case LABEL_MSG4: /* Setup packet: expected only in state SENTMSG3 */ if (st->state!=SITE_SENTMSG3) { + if ((st->state==SITE_SENTMSG5) && + setup_late_msg_ok(st,buf,msgtype,source)) + break; slog(st,LOG_UNEXPECTED,"unexpected MSG4"); } else if (process_msg4(st,buf,source)) { transport_setup_msgok(st,source); @@ -2087,7 +2165,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME); st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES); st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL); - st->wait_timeout= CFG_NUMBER("wait-time", WAIT_TIME); + st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME); st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0); st->mobile_peer_expiry= dict_read_number( @@ -2127,7 +2205,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, /* The information we expect to see in incoming messages of type 1 */ /* fixme: lots of unchecked overflows here, but the results are only corrupted packets rather than undefined behaviour */ - st->setup_priority=(strcmp(st->localname,st->remotename)>0); + st->our_name_later=(strcmp(st->localname,st->remotename)>0); buffer_new(&st->buffer,SETUP_BUFFER_LEN); @@ -2159,6 +2237,9 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, st->local_capabilities |= capbit; } + if (st->local_mobile || st->peer_mobile) + st->local_capabilities |= CAPAB_PRIORITY_MOBILE; + /* We need to register the remote networks with the netlink device */ uint32_t netlink_mtu; /* local virtual interface mtu */ st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu); @@ -2262,11 +2343,18 @@ static void transport_record_peers(struct site *st, transport_peers *peers, * * Caller must first call transport_peers_expire. */ - if (naddrs==1 && peers->npeers>=1 && - comm_addr_equal(&addrs[0], &peers->peers[0].addr)) { - /* optimisation, also avoids debug for trivial updates */ - peers->peers[0].last = *tv_now; - return; + if (naddrs==1) { + /* avoids debug for uninteresting updates */ + int i; + for (i=0; inpeers; i++) { + if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) { + memmove(peers->peers+1, peers->peers, + sizeof(peers->peers[0]) * i); + peers->peers[0].addr = addrs[0]; + peers->peers[0].last = *tv_now; + return; + } + } } int old_npeers=peers->npeers;