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bird/proto/babel/config.Y
Ondrej Zajicek (work) 321ff8c404 Babel: Make sure intervals do not overflow
Intervals are carried as 16-bit centisecond values, but kept internally
in 16-bit second values, which causes a potential for overflow. This adds
some checks to make sure this does not happen.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
2016-07-19 11:57:20 +02:00

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/*
* BIRD -- Babel Configuration
*
* Copyright (c) 2015-2016 Toke Hoiland-Jorgensen
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
CF_HDR
#include "proto/babel/babel.h"
#include "nest/iface.h"
CF_DEFINES
#define BABEL_CFG ((struct babel_config *) this_proto)
#define BABEL_IFACE ((struct babel_iface_config *) this_ipatt)
CF_DECLS
CF_KEYWORDS(BABEL, METRIC, RXCOST, HELLO, UPDATE, INTERVAL, PORT, WIRED,
WIRELESS, RX, TX, BUFFER, LENGTH, CHECK, LINK, BABEL_METRIC)
CF_GRAMMAR
CF_ADDTO(proto, babel_proto)
babel_proto_start: proto_start BABEL
{
this_proto = proto_config_new(&proto_babel, $1);
init_list(&BABEL_CFG->iface_list);
};
babel_proto_item:
proto_item
| INTERFACE babel_iface
;
babel_proto_opts:
/* empty */
| babel_proto_opts babel_proto_item ';'
;
babel_proto:
babel_proto_start proto_name '{' babel_proto_opts '}';
babel_iface_start:
{
this_ipatt = cfg_allocz(sizeof(struct babel_iface_config));
add_tail(&BABEL_CFG->iface_list, NODE this_ipatt);
init_list(&this_ipatt->ipn_list);
BABEL_IFACE->port = BABEL_PORT;
BABEL_IFACE->type = BABEL_IFACE_TYPE_WIRED;
BABEL_IFACE->tx_tos = IP_PREC_INTERNET_CONTROL;
BABEL_IFACE->tx_priority = sk_priority_control;
BABEL_IFACE->check_link = 1;
};
babel_iface_finish:
{
if (BABEL_IFACE->type == BABEL_IFACE_TYPE_WIRELESS)
{
if (!BABEL_IFACE->hello_interval)
BABEL_IFACE->hello_interval = BABEL_HELLO_INTERVAL_WIRELESS;
if (!BABEL_IFACE->rxcost)
BABEL_IFACE->rxcost = BABEL_RXCOST_WIRELESS;
}
else
{
if (!BABEL_IFACE->hello_interval)
BABEL_IFACE->hello_interval = BABEL_HELLO_INTERVAL_WIRED;
if (!BABEL_IFACE->rxcost)
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 = 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>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"); }
| TX LENGTH expr { BABEL_IFACE->tx_length = $3; if (($3<256) || ($3>65535)) cf_error("TX length must be in range 256-65535"); }
| TX tos { BABEL_IFACE->tx_tos = $2; }
| TX PRIORITY expr { BABEL_IFACE->tx_priority = $3; }
| CHECK LINK bool { BABEL_IFACE->check_link = $3; }
;
babel_iface_opts:
/* empty */
| babel_iface_opts babel_iface_item ';'
;
babel_iface_opt_list:
/* empty */
| '{' babel_iface_opts '}'
;
babel_iface:
babel_iface_start iface_patt_list_nopx babel_iface_opt_list babel_iface_finish;
CF_ADDTO(dynamic_attr, BABEL_METRIC { $$ = f_new_dynamic_attr(EAF_TYPE_INT | EAF_TEMP, T_INT, EA_BABEL_METRIC); })
CF_CLI_HELP(SHOW BABEL, ..., [[Show information about Babel protocol]]);
CF_CLI(SHOW BABEL INTERFACES, optsym opttext, [<name>] [\"<interface>\"], [[Show information about Babel interfaces]])
{ babel_show_interfaces(proto_get_named($4, &proto_babel), $5); };
CF_CLI(SHOW BABEL NEIGHBORS, optsym opttext, [<name>] [\"<interface>\"], [[Show information about Babel neighbors]])
{ babel_show_neighbors(proto_get_named($4, &proto_babel), $5); };
CF_CLI(SHOW BABEL ENTRIES, optsym opttext, [<name>], [[Show information about Babel prefix entries]])
{ babel_show_entries(proto_get_named($4, &proto_babel)); };
CF_CODE
CF_END