X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=site.c;h=db1452394bf67b7f173cb8133dd2793c573f24eb;hb=b2de6bd2d9b5e9047a660e926c4adb17da54fc29;hp=9ba1a2857051787978c5dec0b1692974dcf4f136;hpb=c215a4bc817daf7b5631236c3c7b6a509479b034;p=secnet.git

diff --git a/site.c b/site.c
index 9ba1a28..db14523 100644
--- a/site.c
+++ b/site.c
@@ -6,7 +6,7 @@
  *
  * secnet is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version d of the License, or
+ * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  * 
  * secnet is distributed in the hope that it will be useful, but
@@ -296,6 +296,7 @@ struct site {
 /* configuration information */
     string_t localname;
     string_t remotename;
+    bool_t keepalive;
     bool_t local_mobile, peer_mobile; /* Mobile client support */
     int32_t transport_peers_max;
     string_t tunname; /* localname<->remotename by default, used in logs */
@@ -304,6 +305,7 @@ struct site {
     uint32_t mtu_target;
     struct netlink_if *netlink;
     struct comm_if **comms;
+    struct comm_clientinfo **commclientinfos;
     int ncomms;
     struct resolver_if *resolver;
     struct log_if *log;
@@ -326,14 +328,14 @@ struct site {
 				      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;
@@ -532,8 +534,10 @@ struct msg {
     char *sig;
 };
 
-static void set_new_transform(struct site *st, char *pk)
+static _Bool set_new_transform(struct site *st, char *pk)
 {
+    _Bool ok;
+
     /* Make room for the shared key */
     st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
     assert(st->sharedsecretlen);
@@ -551,15 +555,18 @@ static void set_new_transform(struct site *st, char *pk)
     /* Set up the transform */
     struct transform_if *generator=st->chosen_transform;
     struct transform_inst_if *generated=generator->create(generator->st);
-    generated->setkey(generated->st,st->sharedsecret,
-		      st->sharedsecretlen,st->setup_priority);
+    ok = generated->setkey(generated->st,st->sharedsecret,
+			   st->sharedsecretlen,st->our_name_later);
+
     dispose_transform(&st->new_transform);
+    if (!ok) return False;
     st->new_transform=generated;
 
     slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
 	 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
 	 st->chosen_transform->capab_transformnum,
 	 st->local_capabilities, st->remote_capabilities);
+    return True;
 }
 
 struct xinfoadd {
@@ -711,6 +718,13 @@ static bool_t unpick_msg(struct site *st, uint32_t type,
     CHECK_AVAIL(msg,m->siglen);
     m->sig=buf_unprepend(msg,m->siglen);
     CHECK_EMPTY(msg);
+
+    /* In `process_msg3_msg4' below, we assume that we can write a nul
+     * terminator following the signature.  Make sure there's enough space.
+     */
+    if (msg->start >= msg->base + msg->alloclen)
+	return False;
+
     return True;
 }
 
@@ -844,7 +858,7 @@ static bool_t process_msg3_msg4(struct site *st, struct msg *m)
     hst=st->hash->init();
     st->hash->update(hst,m->hashstart,m->hashlen);
     st->hash->final(hst,hash);
-    /* Terminate signature with a '0' - cheating, but should be ok */
+    /* Terminate signature with a '0' - already checked that this will fit */
     m->sig[m->siglen]=0;
     if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
 	slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
@@ -903,7 +917,7 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
     st->random->generate(st->random->st,st->dh->len,st->dhsecret);
 
     /* Generate the shared key and set up the transform */
-    set_new_transform(st,m.pk);
+    if (!set_new_transform(st,m.pk)) return False;
 
     return True;
 }
@@ -934,7 +948,7 @@ static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
     m.pk[m.pklen]=0;
 
     /* Generate the shared key and set up the transform */
-    set_new_transform(st,m.pk);
+    if (!set_new_transform(st,m.pk)) return False;
 
     return True;
 }
@@ -1129,7 +1143,8 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
 
  skew:
     slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
-    return False;
+    assert(problem);
+    return problem;
 }
 
 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
@@ -1146,6 +1161,10 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
     case LABEL_MSG7:
 	/* We must forget about the current session. */
 	delete_keys(st,"request from peer",LOG_SEC);
+	/* probably, the peer is shutting down, and this is going to fail,
+	 * but we need to be trying to bring the link up again */
+	if (st->keepalive)
+	    initiate_key_setup(st,"peer requested key teardown",0);
 	return True;
     case LABEL_MSG9:
 	/* Deliver to netlink layer */
@@ -1164,16 +1183,34 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
 }
 
 static void dump_packet(struct site *st, struct buffer_if *buf,
-			const struct comm_addr *addr, bool_t incoming)
+			const struct comm_addr *addr, bool_t incoming,
+			bool_t ok)
 {
     uint32_t dest=get_uint32(buf->start);
     uint32_t source=get_uint32(buf->start+4);
     uint32_t msgtype=get_uint32(buf->start+8);
 
     if (st->log_events & LOG_DUMP)
-	slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
+	slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
 	       st->tunname,incoming?"incoming":"outgoing",
-	       dest,source,msgtype);
+	       dest,source,msgtype,comm_addr_to_string(addr),
+	       ok?"":" - fail");
+}
+
+static bool_t comm_addr_sendmsg(struct site *st,
+				const struct comm_addr *dest,
+				struct buffer_if *buf)
+{
+    int i;
+    struct comm_clientinfo *commclientinfo = 0;
+
+    for (i=0; i < st->ncomms; i++) {
+	if (st->comms[i] == dest->comm) {
+	    commclientinfo = st->commclientinfos[i];
+	    break;
+	}
+    }
+    return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
 }
 
 static uint32_t site_status(void *st)
@@ -1425,8 +1462,11 @@ static void enter_state_run(struct site *st)
     FILLZERO(st->remoteN);
     dispose_transform(&st->new_transform);
     memset(st->dhsecret,0,st->dh->len);
-    memset(st->sharedsecret,0,st->sharedsecretlen);
+    if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
     set_link_quality(st);
+
+    if (st->keepalive && !current_valid(st))
+	initiate_key_setup(st, "keepalive", 0);
 }
 
 static bool_t ensure_resolving(struct site *st)
@@ -1485,6 +1525,7 @@ 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 ||
@@ -1600,8 +1641,8 @@ static void generate_send_prod(struct site *st,
     slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
     st->allow_send_prod=0;
     generate_prod(st,&st->scratch);
-    dump_packet(st,&st->scratch,source,False);
-    source->comm->sendmsg(source->comm->st, &st->scratch, source);
+    bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
+    dump_packet(st,&st->scratch,source,False,ok);
 }
 
 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
@@ -1714,6 +1755,15 @@ 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;
+}
+
 /* 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
@@ -1734,7 +1784,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	if (!named_for_us(st,buf,msgtype,&named_msg))
 	    return False;
 	/* It's a MSG1 addressed to us. Decide what to do about it. */
-	dump_packet(st,buf,source,True);
+	dump_packet(st,buf,source,True,True);
 	if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
 	    st->state==SITE_WAIT) {
 	    /* We should definitely process it */
@@ -1755,13 +1805,14 @@ 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 */
@@ -1784,7 +1835,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
     if (msgtype==LABEL_PROD) {
 	if (!named_for_us(st,buf,msgtype,&named_msg))
 	    return False;
-	dump_packet(st,buf,source,True);
+	dump_packet(st,buf,source,True,True);
 	if (st->state!=SITE_RUN) {
 	    slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
 	} else if (current_valid(st)) {
@@ -1797,7 +1848,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
     }
     if (dest==st->index) {
 	/* Explicitly addressed to us */
-	if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
+	if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
 	switch (msgtype) {
 	case LABEL_NAK:
 	    /* If the source is our current peer then initiate a key setup,
@@ -1965,6 +2016,8 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->localname=dict_read_string(dict, "local-name", True, "site", loc);
     st->remotename=dict_read_string(dict, "name", True, "site", loc);
 
+    st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
+
     st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
     st->local_mobile=
 	dict_read_bool(dict,"local-mobile",False,"site",loc,False);
@@ -2014,6 +2067,14 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
 
     GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
 
+    NEW_ARY(st->commclientinfos, st->ncomms);
+    dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
+    for (i=0; i<st->ncomms; i++) {
+	st->commclientinfos[i] =
+	    !comminfo ? 0 :
+	    st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
+    }
+
     st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
     st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
     st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
@@ -2077,7 +2138,7 @@ 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);
 
@@ -2109,6 +2170,9 @@ 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);
@@ -2212,11 +2276,18 @@ 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; i<peers->npeers; 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;
@@ -2347,10 +2418,9 @@ void transport_xmit(struct site *st, transport_peers *peers,
     int nfailed=0;
     for (slot=0; slot<peers->npeers; slot++) {
 	transport_peer *peer=&peers->peers[slot];
+	bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
 	if (candebug)
-	    dump_packet(st, buf, &peer->addr, False);
-	bool_t ok =
-	    peer->addr.comm->sendmsg(peer->addr.comm->st, buf, &peer->addr);
+	    dump_packet(st, buf, &peer->addr, False, ok);
 	if (!ok) {
 	    failed |= 1U << slot;
 	    nfailed++;
@@ -2372,12 +2442,14 @@ void transport_xmit(struct site *st, transport_peers *peers,
 	    transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
 	    assert(wslot+nfailed == peers->npeers);
 	    COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
+	    transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
 	}
     } else {
 	if (failed && peers->npeers > 1) {
 	    int wslot=0;
 	    transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
 	    peers->npeers=wslot;
+	    transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
 	}
     }
 }