Fix bugs revealed by 'rhizomeprotocol' test

Was not transmitting actual HTTP server port in rhizome announcements, was
always transmitting port 4110.

When trying for a free HTTP server port, sometimes bind() succeeds but listen()
fails with EADDRINUSE, so new logic to deal with that.

overlay_interface.c

@@ -859,7 +859,7 @@ int overlay_tick_interface(int i, long long now)
   overlay_stuff_packet_from_queue(i,e,OQ_ORDINARY,now,pax,&frame_pax,MAX_FRAME_PAX);
   overlay_stuff_packet_from_queue(i,e,OQ_OPPORTUNISTIC,now,pax,&frame_pax,MAX_FRAME_PAX);
   /* 5. XXX Fill the packet up to a suitable size with anything that seems a good idea */
-  if (rhizome_enabled())
+  if (rhizome_enabled() && rhizome_http_server_running())
     overlay_rhizome_add_advertisements(i,e);
 
   if (debug&DEBUG_PACKETCONSTRUCTION)

rhizome.h

@@ -128,6 +128,7 @@ typedef struct rhizome_manifest {
 
 extern long long rhizome_space;
 extern int rhizome_fetch_interval_ms;
+extern unsigned short rhizome_http_server_port;
 
 int rhizome_configure();
 

rhizome_http.c

@@ -89,9 +89,9 @@ struct profile_total connection_stats;
 
 /*
   HTTP server and client code for rhizome transfers.
-
  */
 
+unsigned short rhizome_http_server_port = 0;
 static int rhizome_server_socket = -1;
 static long long rhizome_server_last_start_attempt = -1;
 
@@ -120,6 +120,11 @@ unsigned char favicon_bytes[]={
 ,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
 int favicon_len=318;
 
+int rhizome_http_server_running()
+{
+  return rhizome_server_socket != -1;
+}
+
 /* Start the Rhizome HTTP server by creating a socket, binding it to an available port, and
    marking it as passive.  If called repeatedly and frequently, this function will only try to start
    the server after a certain time has elapsed since the last attempt.
@@ -141,54 +146,62 @@ int rhizome_http_server_start()
   if (debug&DEBUG_RHIZOME)
     DEBUGF("Starting rhizome HTTP server");
 
-  rhizome_server_socket = socket(AF_INET,SOCK_STREAM,0);
-  if (rhizome_server_socket == -1) {
-    WHY_perror("socket");
-    return WHY("Failed to start rhizome HTTP server");
-  }
-
-  int on=1;
-  if (setsockopt(rhizome_server_socket, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)) == -1) {
-    WHY_perror("setsockopt(REUSEADDR)");
-    close(rhizome_server_socket);
-    rhizome_server_socket = -1;
-    return WHY("Failed to start rhizome HTTP server");
-  }
-
-  /* Starting at the default port, look for a free port to bind to. */
-  struct sockaddr_in address;
-  bzero((char *) &address, sizeof(address));
-  address.sin_family = AF_INET;
-  address.sin_addr.s_addr = INADDR_ANY;
-  int port = RHIZOME_HTTP_PORT;
-  int result = -1;
-  do {
+  unsigned short port;
+  for (port = RHIZOME_HTTP_PORT; port <= RHIZOME_HTTP_PORT_MAX; ++port) {
+    /* Create a new socket, reusable and non-blocking. */
+    if (rhizome_server_socket == -1) {
+      rhizome_server_socket = socket(AF_INET,SOCK_STREAM,0);
+      if (rhizome_server_socket == -1) {
+	WHY_perror("socket");
+	goto error;
+      }
+      int on=1;
+      if (setsockopt(rhizome_server_socket, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)) == -1) {
+	WHY_perror("setsockopt(REUSEADDR)");
+	goto error;
+      }
+      if (ioctl(rhizome_server_socket, FIONBIO, (char *)&on) == -1) {
+	WHY_perror("ioctl(FIONBIO)");
+	goto error;
+      }
+    }
+    /* Bind it to the next port we want to try. */
+    struct sockaddr_in address;
+    bzero((char *) &address, sizeof(address));
+    address.sin_family = AF_INET;
+    address.sin_addr.s_addr = INADDR_ANY;
     address.sin_port = htons(port);
-    result = bind(rhizome_server_socket, (struct sockaddr *) &address, sizeof(address));
-  } while (result == -1 && errno == EADDRINUSE && ++port <= RHIZOME_HTTP_PORT_MAX);
-  if (result == -1) {
-    WHY_perror("bind");
+    if (bind(rhizome_server_socket, (struct sockaddr *) &address, sizeof(address)) == -1) {
+      if (errno != EADDRINUSE) {
+	WHY_perror("bind");
+	goto error;
+      }
+    } else {
+      /* We bound to a port.  The battle is half won.  Now we have to successfully listen on that
+	port, which could also fail with EADDRINUSE, in which case we have to scrap the socket and
+	create a new one, because once bound, a socket stays bound.
+      */
+      if (listen(rhizome_server_socket, 20) != -1)
+	goto success;
+      if (errno != EADDRINUSE) {
+	WHY_perror("listen");
+	goto error;
+      }
+      close(rhizome_server_socket);
+      rhizome_server_socket = -1;
+    }
+  }
+  WHYF("No ports available in range %u to %u", RHIZOME_HTTP_PORT, RHIZOME_HTTP_PORT_MAX);
+error:
+  if (rhizome_server_socket != -1) {
     close(rhizome_server_socket);
     rhizome_server_socket = -1;
-    return WHY("Failed to start rhizome HTTP server");
-  }
-
-  if (ioctl(rhizome_server_socket, FIONBIO, (char *)&on) == -1) {
-    WHY_perror("ioctl(FIONBIO)");
-    close(rhizome_server_socket);
-    rhizome_server_socket = -1;
-    return WHY("Failed to start rhizome HTTP server");
-  }
-
-  if (listen(rhizome_server_socket, 20) == -1) {
-    WHY_perror("listen");
-    close(rhizome_server_socket);
-    rhizome_server_socket = -1;
-    return WHY("Failed to start rhizome HTTP server");
   }
+  return WHY("Failed to start rhizome HTTP server");
 
+success:
   INFOF("Started Rhizome HTTP server on port %d, fd = %d", port, rhizome_server_socket);
-
+  rhizome_http_server_port = port;
   /* Add Rhizome HTTPd server to list of file descriptors to watch */
   server_alarm.function = rhizome_server_poll;
   server_stats.name="rhizome_server_poll";
@@ -196,8 +209,8 @@ int rhizome_http_server_start()
   server_alarm.poll.fd = rhizome_server_socket;
   server_alarm.poll.events = POLLIN;
   watch(&server_alarm);
-
   return 0;
+
 }
 
 void rhizome_client_poll(struct sched_ent *alarm)

rhizome_packetformats.c

@@ -76,7 +76,6 @@ int overlay_rhizome_add_advertisements(int interface_number,overlay_buffer *e)
 {
   IN();
   int voice_mode=0;
-  unsigned short int http_port = RHIZOME_HTTP_PORT;
 
   /* behave differently during voice mode.
      Basically don't encourage people to grab stuff from us, but keep
@@ -130,7 +129,7 @@ int overlay_rhizome_add_advertisements(int interface_number,overlay_buffer *e)
    */
   ob_append_byte(e,3+skipmanifests);
   /* Rhizome HTTP server port number (2 bytes) */
-  ob_append_short(e, http_port);
+  ob_append_short(e, rhizome_http_server_port);
 
   /* XXX Should add priority bundles here.
      XXX Should prioritise bundles for subscribed groups, Serval-authorised files

serval.h

@@ -155,6 +155,7 @@ extern int returnMultiVars;
 extern char *gatewayspec;
 
 int rhizome_enabled();
+int rhizome_http_server_running();
 const char *rhizome_datastore_path();
 
 extern struct in_addr client_addr;

tests/rhizomeprotocol

@@ -28,7 +28,6 @@ teardown() {
    stop_all_servald_servers
    kill_all_servald_processes
    assert_no_servald_processes
-   tfw_cat $LOGA $LOGB
 }
 
 setup_rhizome() {