X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=site.c;h=f9c2f087823d191f2b056032ff4c5a28b3c90eef;hb=5c19b79c7c817a28a1582970b2685c98e05b2de5;hp=e8dba8734861280a200b71c0aeb5653ecc01dc96;hpb=e5d8c16e9249b2f96931c74f3fddd2cbbcc04a2c;p=secnet.git

diff --git a/site.c b/site.c
index e8dba87..f9c2f08 100644
--- a/site.c
+++ b/site.c
@@ -267,6 +267,7 @@ struct site {
     uint32_t state;
     uint64_t now; /* Most recently seen time */
     bool_t allow_send_prod;
+    bool_t resolving;
 
     /* The currently established session */
     struct data_key current;
@@ -319,23 +320,58 @@ static uint32_t event_log_priority(struct site *st, uint32_t event)
     }
 }
 
-static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
-FORMAT(printf,3,4);
-static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
+static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
+FORMAT(printf,3,0);
+static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
 {
-    va_list ap;
     uint32_t class;
 
     class=event_log_priority(st, event);
     if (class) {
-	va_start(ap,msg);
 	slilog_part(st->log,class,"%s: ",st->tunname);
 	vslilog_part(st->log,class,msg,ap);
 	slilog_part(st->log,class,"\n");
-	va_end(ap);
     }
 }
 
+static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
+FORMAT(printf,3,4);
+static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
+{
+    va_list ap;
+    va_start(ap,msg);
+    vslog(st,event,msg,ap);
+    va_end(ap);
+}
+
+static void logtimeout(struct site *st, const char *fmt, ...)
+FORMAT(printf,2,3);
+static void logtimeout(struct site *st, const char *fmt, ...)
+{
+    uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
+    if (!class)
+	return;
+
+    va_list ap;
+    va_start(ap,fmt);
+
+    slilog_part(st->log,class,"%s: ",st->tunname);
+    vslilog_part(st->log,class,fmt,ap);
+
+    const char *delim;
+    int i;
+    for (i=0, delim=" (tried ";
+	 i<st->setup_peers.npeers;
+	 i++, delim=", ") {
+	transport_peer *peer=&st->setup_peers.peers[i];
+	const char *s=comm_addr_to_string(&peer->addr);
+	slilog_part(st->log,class,"%s%s",delim,s);
+    }
+
+    slilog_part(st->log,class,")\n");
+    va_end(ap);
+}
+
 static void set_link_quality(struct site *st);
 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
 static void delete_one_key(struct site *st, struct data_key *key,
@@ -1082,7 +1118,7 @@ static bool_t send_msg(struct site *st)
 	st->retries--;
 	return True;
     } else if (st->state==SITE_SENTMSG5) {
-	slog(st,LOG_SETUP_TIMEOUT,"timed out sending MSG5, stashing new key");
+	logtimeout(st,"timed out sending MSG5, stashing new key");
 	/* We stash the key we have produced, in case it turns out that
 	 * our peer did see our MSG5 after all and starts using it. */
 	/* This is a bit like some of activate_new_key */
@@ -1100,7 +1136,7 @@ static bool_t send_msg(struct site *st)
 	enter_state_wait(st);
 	return False;
     } else {
-	slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet "
+	logtimeout(st,"timed out sending key setup packet "
 	    "(in state %s)",state_name(st->state));
 	enter_state_wait(st);
 	return False;
@@ -1112,6 +1148,8 @@ static void site_resolve_callback(void *sst, struct in_addr *address)
     struct site *st=sst;
     struct comm_addr ca_buf, *ca_use;
 
+    st->resolving=False;
+
     if (st->state!=SITE_RESOLVE) {
 	slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly");
 	return;
@@ -1139,6 +1177,7 @@ static void site_resolve_callback(void *sst, struct in_addr *address)
 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
 				 const struct comm_addr *prod_hint)
 {
+    /* Reentrancy hazard: can call enter_new_state/enter_state_* */
     if (st->state!=SITE_RUN) return False;
     slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
     if (st->address) {
@@ -1249,14 +1288,33 @@ static void enter_state_run(struct site *st)
     set_link_quality(st);
 }
 
+static bool_t ensure_resolving(struct site *st)
+{
+    /* Reentrancy hazard: may call site_resolve_callback and hence
+     * enter_new_state, enter_state_* and generate_msg*. */
+    if (st->resolving)
+        return True;
+
+    /* resolver->request might reentrantly call site_resolve_callback
+     * which will clear st->resolving, so we need to set it beforehand
+     * rather than afterwards; also, it might return False, in which
+     * case we have to clear ->resolving again. */
+    st->resolving=True;
+    bool_t ok = st->resolver->request(st->resolver->st,st->address,
+				      site_resolve_callback,st);
+    if (!ok)
+	st->resolving=False;
+
+    return ok;
+}
+
 static bool_t enter_state_resolve(struct site *st)
 {
+    /* Reentrancy hazard!  See ensure_resolving. */
     state_assert(st,st->state==SITE_RUN);
     slog(st,LOG_STATE,"entering state RESOLVE");
     st->state=SITE_RESOLVE;
-    st->resolver->request(st->resolver->st,st->address,
-			  site_resolve_callback,st);
-    return True;
+    return ensure_resolving(st);
 }
 
 static bool_t enter_new_state(struct site *st, uint32_t next)
@@ -1826,6 +1884,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
 				       log_event_table,"site");
 
+    st->resolving=False;
     st->allow_send_prod=0;
 
     st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
@@ -1916,14 +1975,14 @@ static void transport_peers_debug(struct site *st, transport_peers *dst,
 	 i++, (argp+=stride?stride:sizeof(*args))) {
 	const struct comm_addr *ca=(void*)argp;
 	slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
-	     i, ca->comm->addr_to_string(ca->comm->st,ca));
+	     i, comm_addr_to_string(ca));
     }
     for (i=0; i<dst->npeers; i++) {
 	struct timeval diff;
 	timersub(tv_now,&dst->peers[i].last,&diff);
 	const struct comm_addr *ca=&dst->peers[i].addr;
 	slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
-	     i, ca->comm->addr_to_string(ca->comm->st,ca),
+	     i, comm_addr_to_string(ca),
 	     (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
     }
 }