Babel: Make sure intervals do not overflow (321ff8c4) · Commits · 戴 / Bird

proto/babel/babel.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -50,10 +50,12 @@
		#define BABEL_INITIAL_HOP_COUNT 255
		#define BABEL_MAX_SEND_INTERVAL 5
		#define BABEL_TIME_UNITS 100 /* On-wire times are counted in centiseconds */

		#define BABEL_SEQNO_REQUEST_EXPIRY 60
		#define BABEL_GARBAGE_INTERVAL 300

		/* Max interval that will not overflow when carried as 16-bit centiseconds */
		#define BABEL_MAX_INTERVAL (0xFFFF/BABEL_TIME_UNITS)

		#define BABEL_OVERHEAD (SIZE_OF_IP_HEADER+UDP_HEADER_LENGTH)
		#define BABEL_MIN_MTU (512 + BABEL_OVERHEAD)

proto/babel/config.Y

+5 −4

Original line number	Diff line number	Diff line
		@@ -77,17 +77,18 @@ babel_iface_finish:
		BABEL_IFACE->rxcost = BABEL_RXCOST_WIRED;
		}

		/* Make sure we do not overflow the 16-bit centisec fields */
		if (!BABEL_IFACE->update_interval)
		BABEL_IFACE->update_interval = BABEL_IFACE->hello_interval*BABEL_UPDATE_INTERVAL_FACTOR;
		BABEL_IFACE->ihu_interval = BABEL_IFACE->hello_interval*BABEL_IHU_INTERVAL_FACTOR;
		BABEL_IFACE->update_interval = MIN_(BABEL_IFACE->hello_interval*BABEL_UPDATE_INTERVAL_FACTOR, BABEL_MAX_INTERVAL);
		BABEL_IFACE->ihu_interval = MIN_(BABEL_IFACE->hello_interval*BABEL_IHU_INTERVAL_FACTOR, BABEL_MAX_INTERVAL);
		};


		babel_iface_item:
		\| PORT expr { BABEL_IFACE->port = $2; if (($2<1) \|\| ($2>65535)) cf_error("Invalid port number"); }
		\| RXCOST expr { BABEL_IFACE->rxcost = $2; if (($2<1) \|\| ($2>65535)) cf_error("Invalid rxcost"); }
		\| HELLO INTERVAL expr { BABEL_IFACE->hello_interval = $3; if (($3<1) \|\| ($3>65535)) cf_error("Invalid hello interval"); }
		\| UPDATE INTERVAL expr { BABEL_IFACE->update_interval = $3; if (($3<1) \|\| ($3>65535)) cf_error("Invalid hello interval"); }
		\| HELLO INTERVAL expr { BABEL_IFACE->hello_interval = $3; if (($3<1) \|\| ($3>BABEL_MAX_INTERVAL)) cf_error("Invalid hello interval"); }
		\| UPDATE INTERVAL expr { BABEL_IFACE->update_interval = $3; if (($3<1) \|\| ($3>BABEL_MAX_INTERVAL)) cf_error("Invalid update interval"); }
		\| TYPE WIRED { BABEL_IFACE->type = BABEL_IFACE_TYPE_WIRED; }
		\| TYPE WIRELESS { BABEL_IFACE->type = BABEL_IFACE_TYPE_WIRELESS; }
		\| RX BUFFER expr { BABEL_IFACE->rx_buffer = $3; if (($3<256) \|\| ($3>65535)) cf_error("RX buffer must be in range 256-65535"); }

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