diff options
Diffstat (limited to 'bgpd/bgp_connection.h')
| -rw-r--r-- | bgpd/bgp_connection.h | 101 |
1 files changed, 63 insertions, 38 deletions
diff --git a/bgpd/bgp_connection.h b/bgpd/bgp_connection.h index 054cd953..d50d2985 100644 --- a/bgpd/bgp_connection.h +++ b/bgpd/bgp_connection.h @@ -90,31 +90,24 @@ enum bgp_fsm_events } ; /*============================================================================== - * BGP Connection Structure + * BGP Connection Structures * - * The BGP Connection is the main data structure for the BGP Engine. + *------------------------------------------------------------------------------ + * Write buffer for connection. * - * When a session terminates, or a connection is shut it may have a short - * independent life, if a NOTIFICATION message is pending. + * NB: when connection is initialised all the pointers are set NULL. * - */ - -/* Write buffer for connection. + * The buffer is not allocated until the TCP connection comes up. * * NB: p_out == p_in => buffer is empty * - * BUT: buffer is not allocated until required, and until then - * p_out == p_in == NULL -- empty does NOT imply usable ! + * BUT: p_out == limit => buffer is not writable. * - * AND: when buffer is emptied, p_out and p_in will be some way down the - * buffer. + * When connection is first initialised all pointers are NULL, so the + * buffer is "empty but not writable". * - * SO: before writing, check for base != NULL and set p_out = p_in = base. - * - * NB: before buffer is allocated base == NULL, but limit is set to NULL + n, - * so that buffer does not appear full. - * - * SO: not full does NOT imply that p_out/p_in/base are set, either ! + * When connection is opened, closed or fails, buffer is set into this + * "empty but not writable" state. */ typedef struct bgp_wbuffer* bgp_wbuffer ; struct bgp_wbuffer @@ -126,7 +119,17 @@ struct bgp_wbuffer uint8_t* limit ; } ; +/* Buffer is allocated for a number of maximum size BGP messages. */ +enum { bgp_wbuff_size = BGP_MSG_MAX_L * 10 } ; +/*============================================================================== + * BGP Connection Structure + * + * The BGP Connection is the main data structure for the BGP Engine. + * + * When a session terminates, or a connection is shut it may have a short + * independent life, if a NOTIFICATION message is pending. + */ struct bgp_connection { bgp_session session ; /* session connection belongs to */ @@ -147,7 +150,7 @@ struct bgp_connection int fsm_active ; /* active in FSM counter */ bgp_fsm_event_t follow_on ; /* event raised within FSM */ - bgp_session_event_t except ; /* exception posted here */ + bgp_session_event_t exception; /* exception posted here */ bgp_notify notification ; /* if any sent/received */ int err ; /* erno, if any */ @@ -201,6 +204,9 @@ extern void bgp_connection_open(bgp_connection connection, int fd) ; extern void +bgp_connection_start(bgp_connection connection, union sockunion* su_local, + union sockunion* su_remote) ; +extern void bgp_connection_enable_accept(bgp_connection connection) ; extern void @@ -218,7 +224,7 @@ bgp_connection_full_close(bgp_connection connection, int unset_timers) ; #define bgp_connection_close(conn) bgp_connection_full_close(conn, 0) #define bgp_connection_close_down(conn) bgp_connection_full_close(conn, 1) -extern void +extern int bgp_connection_part_close(bgp_connection connection) ; extern void @@ -236,7 +242,7 @@ bgp_connection_queue_add(bgp_connection connection) ; extern void bgp_connection_queue_del(bgp_connection connection) ; -extern void +extern int bgp_connection_queue_process(void) ; Inline int @@ -251,12 +257,28 @@ bgp_connection_add_pending(bgp_connection connection, mqueue_block mqb, bgp_connection* is_pending) ; /*------------------------------------------------------------------------------ + * Set buffer *unwritable* (buffer appears full, but nothing pending). + */ +Inline void +bgp_write_buffer_unwritable(bgp_wbuffer wb) +{ + wb->p_in = wb->p_out = wb->limit ; +} ; + +/*------------------------------------------------------------------------------ + * If allocated: set buffer empty + * If unallocated: buffer remains *unwritable* + */ +Inline void +bgp_write_buffer_reset(bgp_wbuffer wb) +{ + wb->p_in = wb->p_out = wb->base ; +} ; + +/*------------------------------------------------------------------------------ * See if do NOT have enough room for what want to write PLUS 1. * - * NB: before using the buffer the caller MUST ensure it has been allocated. - * - * Unallocated buffer is made to appear to have room for one maximum - * size BGP message. + * NB: there is never any room in an unallocated buffer. */ Inline int bgp_write_buffer_cannot(bgp_wbuffer wb, size_t want) @@ -267,30 +289,35 @@ bgp_write_buffer_cannot(bgp_wbuffer wb, size_t want) /*------------------------------------------------------------------------------ * Full if NOT enough room for a maximum size BGP message + 1 * - * NB: this will be FALSE if the buffer has not been allocated -- because can - * allocate a buffer and proceed if required. + * NB: there is never any room in an unallocated buffer. */ enum { bgp_write_buffer_full_threshold = BGP_MSG_MAX_L + 1 } ; Inline int -bgp_write_buffer_full(bgp_wbuffer wb) +bgp_write_buffer_cannot_max(bgp_wbuffer wb) { return bgp_write_buffer_cannot(wb, BGP_MSG_MAX_L) ; } ; /*------------------------------------------------------------------------------ - * Empty if in and out pointers are equal. - * - * NB: buffer is empty if it has not yet been allocated. - * - * NOT empty => allocated. + * See if buffer has anything in it. * - * NB: empty does NOT imply that both pointers are at the start of the buffer. + * If empty, ensures that the buffer has been allocated, and sets the pointers + * to the start of the buffer -- so all set to go. */ Inline int bgp_write_buffer_empty(bgp_wbuffer wb) { - return (wb->p_out == wb->p_in) ; + if (wb->p_out < wb->p_in) + return 0 ; /* not empty => has buffer */ + + dassert(wb->p_out == wb->p_in) ; + + passert(wb->base != NULL) ; /* must have buffer */ + + bgp_write_buffer_reset(wb) ; /* pointers to start of buffer */ + + return 1 ; /* empty and all ready to go */ } ; /*------------------------------------------------------------------------------ @@ -299,8 +326,6 @@ bgp_write_buffer_empty(bgp_wbuffer wb) * NB: if returns 0, may not yet have been allocated. * * > 0 => allocated. - * - * NB: 0 does NOT imply that both pointers are at the start of the buffer. */ Inline int bgp_write_buffer_pending(bgp_wbuffer wb) @@ -313,9 +338,9 @@ bgp_write_buffer_pending(bgp_wbuffer wb) * As above, for connection */ Inline int -bgp_connection_write_full(bgp_connection connection) +bgp_connection_write_cannot_max(bgp_connection connection) { - return bgp_write_buffer_full(&connection->wbuff) ; + return bgp_write_buffer_cannot_max(&connection->wbuff) ; } ; /*------------------------------------------------------------------------------ |