chiark / gitweb /
site: Change return value of decrypt_msg0
[secnet.git] / site.c
diff --git a/site.c b/site.c
index 681e595a4c1e64ab97a50d21a250f57841b31500..bc902ad92397c3fcf94a3bdab1e7ff0ff559a78d 100644 (file)
--- a/site.c
+++ b/site.c
@@ -328,14 +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;
@@ -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);                        \
 }
@@ -556,7 +557,7 @@ 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;
@@ -1029,8 +1030,9 @@ 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 +1072,13 @@ 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 +1091,15 @@ 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)
+    if (problem==transform_apply_seqrange)
        goto skew;
 
     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
@@ -1113,9 +1116,9 @@ 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)
+    if (problem==transform_apply_seqrange)
        goto skew;
 
     if (st->state==SITE_SENTMSG5) {
@@ -1129,9 +1132,9 @@ 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)
+       if (problem==transform_apply_seqrange)
            goto skew;
     }
 
@@ -1139,7 +1142,8 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0,
         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);
@@ -1151,8 +1155,10 @@ static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
                           const struct comm_addr *src)
 {
     uint32_t type;
+    transform_apply_return problem;
 
-    if (!decrypt_msg0(st,msg0,src))
+    problem = decrypt_msg0(st,msg0,src);
+    if (problem)
        return False;
 
     CHECK_AVAIL(msg0,4);
@@ -1525,6 +1531,7 @@ 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 ||
@@ -1754,6 +1761,15 @@ 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
@@ -1795,13 +1811,14 @@ 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 */
@@ -2127,7 +2144,7 @@ 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 +2176,9 @@ 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);