X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=site.c;h=1bf8dec7682c83256bafb8be22fb7b5233bc4670;hb=19e9a588dc058584fbda9d31080a2581c3fd5269;hp=9d09ebc1e53c92988004ec0feef14826b6eb87e8;hpb=446353cd8ce62c2feecafb91e7a6cbe97aaa8914;p=secnet.git

diff --git a/site.c b/site.c
index 9d09ebc..1bf8dec 100644
--- a/site.c
+++ b/site.c
@@ -32,6 +32,13 @@
 #define DEFAULT_SETUP_RETRIES 5
 #define DEFAULT_SETUP_RETRY_INTERVAL             (2*1000) /* [ms] */
 #define DEFAULT_WAIT_TIME                       (20*1000) /* [ms] */
+
+#define DEFAULT_MOBILE_KEY_LIFETIME      (2*24*3600*1000) /* [ms] */
+#define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
+#define DEFAULT_MOBILE_SETUP_RETRIES 30
+#define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL      (1*1000) /* [ms] */
+#define DEFAULT_MOBILE_WAIT_TIME                (10*1000) /* [ms] */
+
 #define DEFAULT_MOBILE_PEER_EXPIRY            (2*60)      /* [s] */
 #define DEFAULT_MOBILE_PEERS_MAX 3 /* send at most this many copies (default) */
 
@@ -207,6 +214,12 @@ static void transport_xmit(struct site *st, transport_peers *peers,
  /***** END of transport peers declarations *****/
 
 
+struct data_key {
+    struct transform_inst_if *transform;
+    uint64_t key_timeout; /* End of life of current key */
+    uint32_t remote_session_id;
+};
+
 struct site {
     closure_t cl;
     struct site_if ops;
@@ -219,7 +232,8 @@ struct site {
     string_t address; /* DNS name for bootstrapping, optional */
     int remoteport; /* Port for bootstrapping, optional */
     struct netlink_if *netlink;
-    struct comm_if *comm;
+    struct comm_if **comms;
+    int ncomms;
     struct resolver_if *resolver;
     struct log_if *log;
     struct random_if *random;
@@ -251,10 +265,7 @@ struct site {
     uint64_t now; /* Most recently seen time */
 
     /* The currently established session */
-    uint32_t remote_session_id;
-    struct transform_inst_if *current_transform;
-    bool_t current_valid;
-    uint64_t current_key_timeout; /* End of life of current key */
+    struct data_key current;
     uint64_t renegotiate_key_time; /* When we can negotiate a new key */
     transport_peers peers; /* Current address(es) of peer for data traffic */
 
@@ -269,6 +280,7 @@ struct site {
     uint8_t localN[NONCELEN]; /* Nonces for key exchange */
     uint8_t remoteN[NONCELEN];
     struct buffer_if buffer; /* Current outgoing key exchange packet */
+    struct buffer_if scratch;
     int32_t retries; /* Number of retries remaining */
     uint64_t timeout; /* Timeout for current state */
     uint8_t *dhsecret;
@@ -313,6 +325,12 @@ static void enter_state_run(struct site *st);
 static bool_t enter_state_resolve(struct site *st);
 static bool_t enter_new_state(struct site *st,uint32_t next);
 static void enter_state_wait(struct site *st);
+static void activate_new_key(struct site *st);
+
+static bool_t current_valid(struct site *st)
+{
+    return st->current.transform->valid(st->current.transform->st);
+}
 
 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
@@ -620,7 +638,6 @@ static bool_t generate_msg5(struct site *st)
     buffer_init(&st->buffer,st->transform->max_start_pad+(4*4));
     /* Give the netlink code an opportunity to put its own stuff in the
        message (configuration information, etc.) */
-    st->netlink->output_config(st->netlink->st,&st->buffer);
     buf_prepend_uint32(&st->buffer,LABEL_MSG5);
     st->new_transform->forwards(st->new_transform->st,&st->buffer,
 				&transform_err);
@@ -633,15 +650,15 @@ static bool_t generate_msg5(struct site *st)
 }
 
 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
-			   const struct comm_addr *src)
+			   const struct comm_addr *src,
+			   struct transform_inst_if *transform)
 {
     struct msg0 m;
     cstring_t transform_err;
 
     if (!unpick_msg0(st,msg5,&m)) return False;
 
-    if (st->new_transform->reverse(st->new_transform->st,
-				   msg5,&transform_err)) {
+    if (transform->reverse(transform->st,msg5,&transform_err)) {
 	/* There's a problem */
 	slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
 	return False;
@@ -652,15 +669,13 @@ static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
 	slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
 	return False;
     }
-    if (!st->netlink->check_config(st->netlink->st,msg5)) {
-	slog(st,LOG_SEC,"MSG5/PING packet contained bad netlink config");
-	return False;
-    }
-    CHECK_EMPTY(msg5);
+    /* Older versions of secnet used to write some config data here
+     * which we ignore.  So we don't CHECK_EMPTY */
     return True;
 }
 
-static bool_t generate_msg6(struct site *st)
+static void create_msg6(struct site *st, struct transform_inst_if *transform,
+			uint32_t session_id)
 {
     cstring_t transform_err;
 
@@ -669,14 +684,16 @@ static bool_t generate_msg6(struct site *st)
     buffer_init(&st->buffer,st->transform->max_start_pad+(4*4));
     /* Give the netlink code an opportunity to put its own stuff in the
        message (configuration information, etc.) */
-    st->netlink->output_config(st->netlink->st,&st->buffer);
     buf_prepend_uint32(&st->buffer,LABEL_MSG6);
-    st->new_transform->forwards(st->new_transform->st,&st->buffer,
-				&transform_err);
+    transform->forwards(transform->st,&st->buffer,&transform_err);
     buf_prepend_uint32(&st->buffer,LABEL_MSG6);
     buf_prepend_uint32(&st->buffer,st->index);
-    buf_prepend_uint32(&st->buffer,st->setup_session_id);
+    buf_prepend_uint32(&st->buffer,session_id);
+}
 
+static bool_t generate_msg6(struct site *st)
+{
+    create_msg6(st,st->new_transform,st->setup_session_id);
     st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
     return True;
 }
@@ -701,34 +718,58 @@ static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
 	slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
 	return False;
     }
-    if (!st->netlink->check_config(st->netlink->st,msg6)) {
-	slog(st,LOG_SEC,"MSG6/PONG packet contained bad netlink config");
+    /* Older versions of secnet used to write some config data here
+     * which we ignore.  So we don't CHECK_EMPTY */
+    return True;
+}
+
+static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0)
+{
+    cstring_t transform_err, newkey_err="n/a";
+    struct msg0 m;
+    uint32_t problem;
+
+    if (!unpick_msg0(st,msg0,&m)) return False;
+
+    /* Keep a copy so we can try decrypting it with multiple keys */
+    buffer_copy(&st->scratch, msg0);
+
+    problem = st->current.transform->reverse(st->current.transform->st,
+					     msg0,&transform_err);
+    if (!problem) return True;
+
+    if (problem==2) {
+	slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err);
 	return False;
     }
-    CHECK_EMPTY(msg6);
-    return True;
+
+    if (st->state==SITE_SENTMSG5) {
+	buffer_copy(msg0, &st->scratch);
+	if (!st->new_transform->reverse(st->new_transform->st,
+					msg0,&newkey_err)) {
+	    /* It looks like we didn't get the peer's MSG6 */
+	    /* This is like a cut-down enter_new_state(SITE_RUN) */
+	    slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
+	    BUF_FREE(&st->buffer);
+	    st->timeout=0;
+	    activate_new_key(st);
+	    return True; /* do process the data in this packet */
+	}
+    }
+
+    slog(st,LOG_SEC,"transform: %s (new: %s)",transform_err,newkey_err);
+    initiate_key_setup(st,"incoming message would not decrypt");
+    return False;
 }
 
 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
 			   const struct comm_addr *src)
 {
-    struct msg0 m;
-    cstring_t transform_err;
     uint32_t type;
 
-    if (!st->current_valid) {
-	slog(st,LOG_DROP,"incoming message but no current key -> dropping");
-	return initiate_key_setup(st,"incoming message but no current key");
-    }
-
-    if (!unpick_msg0(st,msg0,&m)) return False;
+    if (!decrypt_msg0(st,msg0))
+	return False;
 
-    if (st->current_transform->reverse(st->current_transform->st,
-				       msg0,&transform_err)) {
-	/* There's a problem */
-	slog(st,LOG_SEC,"transform: %s",transform_err);
-	return initiate_key_setup(st,"incoming message would not decrypt");
-    }
     CHECK_AVAIL(msg0,4);
     type=buf_unprepend_uint32(msg0);
     switch(type) {
@@ -796,7 +837,7 @@ static void site_resolve_callback(void *sst, struct in_addr *address)
     }
     if (address) {
 	FILLZERO(ca_buf);
-	ca_buf.comm=st->comm;
+	ca_buf.comm=st->comms[0];
 	ca_buf.sin.sin_family=AF_INET;
 	ca_buf.sin.sin_port=htons(st->remoteport);
 	ca_buf.sin.sin_addr=*address;
@@ -834,17 +875,16 @@ static void activate_new_key(struct site *st)
 
     /* We have two transform instances, which we swap between active
        and setup */
-    t=st->current_transform;
-    st->current_transform=st->new_transform;
+    t=st->current.transform;
+    st->current.transform=st->new_transform;
     st->new_transform=t;
 
     t->delkey(t->st);
     st->timeout=0;
-    st->current_valid=True;
-    st->current_key_timeout=st->now+st->key_lifetime;
+    st->current.key_timeout=st->now+st->key_lifetime;
     st->renegotiate_key_time=st->now+st->key_renegotiate_time;
     transport_peers_copy(st,&st->peers,&st->setup_peers);
-    st->remote_session_id=st->setup_session_id;
+    st->current.remote_session_id=st->setup_session_id;
 
     slog(st,LOG_ACTIVATE_KEY,"new key activated");
     enter_state_run(st);
@@ -852,12 +892,11 @@ static void activate_new_key(struct site *st)
 
 static void delete_key(struct site *st, cstring_t reason, uint32_t loglevel)
 {
-    if (st->current_valid) {
+    if (current_valid(st)) {
 	slog(st,loglevel,"session closed (%s)",reason);
 
-	st->current_valid=False;
-	st->current_transform->delkey(st->current_transform->st);
-	st->current_key_timeout=0;
+	st->current.transform->delkey(st->current.transform->st);
+	st->current.key_timeout=0;
 	set_link_quality(st);
     }
 }
@@ -878,7 +917,7 @@ static void enter_state_stop(struct site *st)
 static void set_link_quality(struct site *st)
 {
     uint32_t quality;
-    if (st->current_valid)
+    if (current_valid(st))
 	quality=LINK_QUALITY_UP;
     else if (st->state==SITE_WAIT || st->state==SITE_STOP)
 	quality=LINK_QUALITY_DOWN;
@@ -990,17 +1029,17 @@ static bool_t send_msg7(struct site *st, cstring_t reason)
 {
     cstring_t transform_err;
 
-    if (st->current_valid && st->buffer.free
+    if (current_valid(st) && st->buffer.free
 	&& transport_peers_valid(&st->peers)) {
 	BUF_ALLOC(&st->buffer,"site:MSG7");
 	buffer_init(&st->buffer,st->transform->max_start_pad+(4*3));
 	buf_append_uint32(&st->buffer,LABEL_MSG7);
 	buf_append_string(&st->buffer,reason);
-	st->current_transform->forwards(st->current_transform->st,
+	st->current.transform->forwards(st->current.transform->st,
 					&st->buffer, &transform_err);
 	buf_prepend_uint32(&st->buffer,LABEL_MSG0);
 	buf_prepend_uint32(&st->buffer,st->index);
-	buf_prepend_uint32(&st->buffer,st->remote_session_id);
+	buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
 	transport_xmit(st,&st->peers,&st->buffer,True);
 	BUF_FREE(&st->buffer);
 	return True;
@@ -1041,10 +1080,10 @@ static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
     st->now=*now;
 
     /* Work out when our next timeout is. The earlier of 'timeout' or
-       'current_key_timeout'. A stored value of '0' indicates no timeout
+       'current.key_timeout'. A stored value of '0' indicates no timeout
        active. */
     site_settimeout(st->timeout, timeout_io);
-    site_settimeout(st->current_key_timeout, timeout_io);
+    site_settimeout(st->current.key_timeout, timeout_io);
 
     return 0; /* success */
 }
@@ -1067,7 +1106,7 @@ static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
 		 st->state);
 	}
     }
-    if (st->current_key_timeout && *now>st->current_key_timeout) {
+    if (st->current.key_timeout && *now>st->current.key_timeout) {
 	delete_key(st,"maximum key life exceeded",LOG_TIMEOUT_KEY);
     }
 }
@@ -1087,15 +1126,15 @@ static void site_outgoing(void *sst, struct buffer_if *buf)
 
     /* In all other states we consider delivering the packet if we have
        a valid key and a valid address to send it to. */
-    if (st->current_valid && transport_peers_valid(&st->peers)) {
+    if (current_valid(st) && transport_peers_valid(&st->peers)) {
 	/* Transform it and send it */
 	if (buf->size>0) {
 	    buf_prepend_uint32(buf,LABEL_MSG9);
-	    st->current_transform->forwards(st->current_transform->st,
+	    st->current.transform->forwards(st->current.transform->st,
 					    buf, &transform_err);
 	    buf_prepend_uint32(buf,LABEL_MSG0);
 	    buf_prepend_uint32(buf,st->index);
-	    buf_prepend_uint32(buf,st->remote_session_id);
+	    buf_prepend_uint32(buf,st->current.remote_session_id);
 	    transport_xmit(st,&st->peers,buf,False);
 	}
 	BUF_FREE(buf);
@@ -1113,6 +1152,9 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 			    const struct comm_addr *source)
 {
     struct site *st=sst;
+
+    if (buf->size < 12) return False;
+
     uint32_t dest=ntohl(*(uint32_t *)buf->start);
 
     if (dest==0) {
@@ -1172,7 +1214,7 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	case 0: /* NAK */
 	    /* If the source is our current peer then initiate a key setup,
 	       because our peer's forgotten the key */
-	    if (get_uint32(buf->start+4)==st->remote_session_id) {
+	    if (get_uint32(buf->start+4)==st->current.remote_session_id) {
 		initiate_key_setup(st,"received a NAK");
 	    } else {
 		slog(st,LOG_SEC,"bad incoming NAK");
@@ -1223,16 +1265,29 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf,
 	    /* Setup packet: expected only in state SENTMSG4 */
 	    /* (may turn up in state RUN if our return MSG6 was lost
 	       and the new key has already been activated. In that
-	       case we should treat it as an ordinary PING packet. We
-	       can't pass it to process_msg5() because the
-	       new_transform will now be unkeyed. XXX) */
-	    if (st->state!=SITE_SENTMSG4) {
-		slog(st,LOG_UNEXPECTED,"unexpected MSG5");
-	    } else if (process_msg5(st,buf,source)) {
-		transport_setup_msgok(st,source);
-		enter_new_state(st,SITE_RUN);
+	       case we discard it. The peer will realise that we
+	       are using the new key when they see our data packets.
+	       Until then the peer's data packets to us get discarded. */
+	    if (st->state==SITE_SENTMSG4) {
+		if (process_msg5(st,buf,source,st->new_transform)) {
+		    transport_setup_msgok(st,source);
+		    enter_new_state(st,SITE_RUN);
+		} else {
+		    slog(st,LOG_SEC,"invalid MSG5");
+		}
+	    } else if (st->state==SITE_RUN) {
+		if (process_msg5(st,buf,source,st->current.transform)) {
+		    slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
+		    transport_setup_msgok(st,source);
+		    create_msg6(st,st->current.transform,
+				st->current.remote_session_id);
+		    transport_xmit(st,&st->peers,&st->buffer,True);
+		    BUF_FREE(&st->buffer);
+		} else {
+		    slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
+		}
 	    } else {
-		slog(st,LOG_SEC,"invalid MSG5");
+		slog(st,LOG_UNEXPECTED,"unexpected MSG5");
 	    }
 	    break;
 	case LABEL_MSG6:
@@ -1281,6 +1336,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     struct site *st;
     item_t *item;
     dict_t *dict;
+    int i;
 
     st=safe_malloc(sizeof(*st),"site_apply");
 
@@ -1300,20 +1356,49 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     dict=item->data.dict;
     st->localname=dict_read_string(dict, "local-name", True, "site", loc);
     st->remotename=dict_read_string(dict, "name", True, "site", loc);
+
+    st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
+    bool_t local_mobile=
+	dict_read_bool(dict,"local-mobile",False,"site",loc,False);
+
     /* Sanity check (which also allows the 'sites' file to include
        site() closures for all sites including our own): refuse to
        talk to ourselves */
     if (strcmp(st->localname,st->remotename)==0) {
 	Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
 		st->localname);
+	if (st->peer_mobile != local_mobile)
+	    cfgfatal(loc,"site","site %s's peer-mobile=%d"
+		    " but our local-mobile=%d\n",
+		    st->localname, st->peer_mobile, local_mobile);
+	free(st);
+	return NULL;
+    }
+    if (st->peer_mobile && local_mobile) {
+	Message(M_WARNING,"site %s: site is mobile but so are we"
+		" -> ignoring this site\n", st->remotename);
 	free(st);
 	return NULL;
     }
+
     assert(index_sequence < 0xffffffffUL);
     st->index = ++index_sequence;
-    st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
     st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
-    st->comm=find_cl_if(dict,"comm",CL_COMM,True,"site",loc);
+
+    list_t *comms_cfg=dict_lookup(dict,"comm");
+    if (!comms_cfg) cfgfatal(loc,"site","closure list \"comm\" not found\n");
+    st->ncomms=list_length(comms_cfg);
+    st->comms=safe_malloc_ary(sizeof(*st->comms),st->ncomms,"comms");
+    assert(st->ncomms);
+    for (i=0; i<st->ncomms; i++) {
+	item_t *item=list_elem(comms_cfg,i);
+	if (item->type!=t_closure)
+	    cfgfatal(loc,"site","comm is not a closure\n");
+	closure_t *cl=item->data.closure;
+	if (cl->type!=CL_COMM) cfgfatal(loc,"site","comm closure wrong type\n");
+	st->comms[i]=cl->interface;
+    }
+
     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);
@@ -1331,7 +1416,8 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
     st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
 
-#define DEFAULT(D) DEFAULT_##D
+#define DEFAULT(D) (st->peer_mobile || local_mobile	\
+                    ? DEFAULT_MOBILE_##D : DEFAULT_##D)
 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
 
     st->key_lifetime=         CFG_NUMBER("key-lifetime",  KEY_LIFETIME);
@@ -1383,28 +1469,42 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
 
     buffer_new(&st->buffer,SETUP_BUFFER_LEN);
 
+    buffer_new(&st->scratch,0);
+    BUF_ALLOC(&st->scratch,"site:scratch");
+
     /* We are interested in poll(), but only for timeouts. We don't have
        any fds of our own. */
     register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
     st->timeout=0;
 
-    st->current_valid=False;
-    st->current_key_timeout=0;
+    st->current.key_timeout=0;
     transport_peers_clear(st,&st->peers);
     transport_peers_clear(st,&st->setup_peers);
     /* XXX mlock these */
     st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
     st->sharedsecret=safe_malloc(st->transform->keylen,"site:sharedsecret");
 
+    /* We need to compute some properties of our comms */
+#define COMPUTE_WORST(pad)			\
+    int worst_##pad=0;				\
+    for (i=0; i<st->ncomms; i++) {		\
+	int thispad=st->comms[i]->pad;		\
+	if (thispad > worst_##pad)		\
+	    worst_##pad=thispad;		\
+    }
+    COMPUTE_WORST(min_start_pad)
+    COMPUTE_WORST(min_end_pad)
+
     /* We need to register the remote networks with the netlink device */
     st->netlink->reg(st->netlink->st, site_outgoing, st,
 		     st->transform->max_start_pad+(4*4)+
-		     st->comm->min_start_pad,
-		     st->transform->max_end_pad+st->comm->min_end_pad);
+		     worst_min_start_pad,
+		     st->transform->max_end_pad+worst_min_end_pad);
     
-    st->comm->request_notify(st->comm->st, st, site_incoming);
+    for (i=0; i<st->ncomms; i++)
+	st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
 
-    st->current_transform=st->transform->create(st->transform->st);
+    st->current.transform=st->transform->create(st->transform->st);
     st->new_transform=st->transform->create(st->transform->st);
 
     enter_state_stop(st);
@@ -1549,7 +1649,7 @@ static void transport_peers_copy(struct site *st, transport_peers *dst,
     dst->npeers=src->npeers;
     memcpy(dst->peers, src->peers, sizeof(*dst->peers) * dst->npeers);
     transport_peers_debug(st,dst,"copy",
-			  src->npeers, &src->peers->addr, sizeof(src->peers));
+			  src->npeers, &src->peers->addr, sizeof(*src->peers));
 }
 
 void transport_xmit(struct site *st, transport_peers *peers,