#include <sys/stat.h>
#include <unistd.h>
#include <netdb.h>
+#include <pthread.h>
#include <RIC_message_types.h> // needed for route manager messages
+#define ALL 1
+#define SOME 0
/*
Passed to a symtab foreach callback to construct a list of pointers from
*counter = 0;
rmr_vlog_force( RMR_VL_DEBUG, "route table stats:\n" );
rmr_vlog_force( RMR_VL_DEBUG, "route table endpoints:\n" );
- rmr_sym_foreach_class( rt->hash, RT_NAME_SPACE, ep_stats, counter ); // run endpoints (names) in the active table
+ rmr_sym_foreach_class( rt->ephash, RT_NAME_SPACE, ep_stats, counter ); // run endpoints (names) in the active table
rmr_vlog_force( RMR_VL_DEBUG, "rtable: %d known endpoints\n", *counter );
rmr_vlog_force( RMR_VL_DEBUG, "route table entries:\n" );
}
}
-// ------------------------------------------------------------------------------------------------
+// ---- utility -----------------------------------------------------------------------------------
/*
Little diddy to trim whitespace and trailing comments. Like shell, trailing comments
must be at the start of a word (i.e. must be immediatly preceeded by whitespace).
return nb;
}
+/*
+ Roll the new table into the active and the active into the old table. We
+ must have the lock on the active table to do this. It's possible that there
+ is no active table (first load), so we have to account for that (no locking).
+*/
+static void roll_tables( uta_ctx_t* ctx ) {
+ if( ctx->rtable != NULL ) { // initially there isn't one, so must check!
+ pthread_mutex_lock( ctx->rtgate ); // must hold lock to move to active
+ ctx->old_rtable = ctx->rtable; // currently active becomes old and allowed to 'drain'
+ ctx->rtable = ctx->new_rtable; // one we've been adding to becomes active
+ pthread_mutex_unlock( ctx->rtgate );
+ } else {
+ ctx->old_rtable = NULL; // ensure there isn't an old reference
+ ctx->rtable = ctx->new_rtable; // make new the active one
+ }
+
+ ctx->new_rtable = NULL;
+}
+
+// ------------ entry update functions ---------------------------------------------------------------
/*
Given a message type create a route table entry and add to the hash keyed on the
message type. Once in the hash, endpoints can be added with uta_add_ep. Size
}
}
+// -------------------------- parse functions --------------------------------------------------
+
/*
Given the tokens from an mme_ar (meid add/replace) entry, add the entries.
the 'owner' which should be the dns name or IP address of an enpoint
if( ctx->new_rtable != NULL ) { // one in progress? this forces it out
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "meid map start: dropping incomplete table\n" );
uta_rt_drop( ctx->new_rtable );
- send_rt_ack( pctx, mbuf, ctx->table_id, !RMR_OK, "table not complete" ); // nack the one that was pending as end never made it
+ ctx->new_rtable = NULL;
+ send_rt_ack( pctx, mbuf, ctx->table_id, !RMR_OK, "table not complete" ); // nack the one that was pending as and never made it
}
if( ctx->table_id != NULL ) {
free( ctx->table_id );
}
- if( ntoks >2 ) {
+ if( ntoks > 2 ) {
ctx->table_id = strdup( clip( tokens[2] ) );
} else {
ctx->table_id = NULL;
}
- ctx->new_rtable = uta_rt_clone_all( ctx->rtable ); // start with a clone of everything (mtype, endpoint refs and meid)
+
+ ctx->new_rtable = prep_new_rt( ctx, ALL ); // start with a clone of everything (mtype, endpoint refs and meid)
ctx->new_rtable->mupdates = 0;
+
if( DEBUG || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "meid_parse: meid map start found\n" );
} else {
if( strcmp( tokens[1], "end" ) == 0 ) { // wrap up the table we were building
if( ntoks > 2 ) { // meid_map | end | <count> |??? given
if( ctx->new_rtable->mupdates != atoi( tokens[2] ) ) { // count they added didn't match what we received
- rmr_vlog( RMR_VL_ERR, "meid_parse: meid map update had wrong number of records: received %d expected %s\n", ctx->new_rtable->mupdates, tokens[2] );
+ rmr_vlog( RMR_VL_ERR, "meid_parse: meid map update had wrong number of records: received %d expected %s\n",
+ ctx->new_rtable->mupdates, tokens[2] );
snprintf( wbuf, sizeof( wbuf ), "missing table records: expected %s got %d\n", tokens[2], ctx->new_rtable->updates );
send_rt_ack( pctx, mbuf, ctx->table_id, !RMR_OK, wbuf );
uta_rt_drop( ctx->new_rtable );
}
if( ctx->new_rtable ) {
- uta_rt_drop( ctx->old_rtable ); // time to drop one that was previously replaced
- ctx->old_rtable = ctx->rtable; // currently active becomes old and allowed to 'drain'
- ctx->rtable = ctx->new_rtable; // one we've been adding to becomes active
- ctx->new_rtable = NULL;
+ roll_tables( ctx ); // roll active to old, and new to active with proper locking
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "end of meid map noticed\n" );
send_rt_ack( pctx, mbuf, ctx->table_id, RMR_OK, NULL );
if( vlevel > 0 ) {
- rmr_vlog_force( RMR_VL_DEBUG, "old route table:\n" );
- rt_stats( ctx->old_rtable );
+ if( ctx->old_rtable != NULL ) {
+ rmr_vlog_force( RMR_VL_DEBUG, "old route table: (ref_count=%d)\n", ctx->old_rtable->ref_count );
+ rt_stats( ctx->old_rtable );
+ } else {
+ rmr_vlog_force( RMR_VL_DEBUG, "old route table was empty\n" );
+ }
rmr_vlog_force( RMR_VL_DEBUG, "new route table:\n" );
rt_stats( ctx->rtable );
}
}
if( ctx->new_rtable ) {
- uta_rt_drop( ctx->old_rtable ); // time to drop one that was previously replaced
- ctx->old_rtable = ctx->rtable; // currently active becomes old and allowed to 'drain'
- ctx->rtable = ctx->new_rtable; // one we've been adding to becomes active
- ctx->new_rtable = NULL;
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog( RMR_VL_DEBUG, "end of route table noticed\n" );
+ roll_tables( ctx ); // roll active to old, and new to active with proper locking
if( vlevel > 0 ) {
- rmr_vlog_force( RMR_VL_DEBUG, "old route table:\n" );
- rt_stats( ctx->old_rtable );
+ if( ctx->old_rtable != NULL ) {
+ rmr_vlog_force( RMR_VL_DEBUG, "old route table: (ref_count=%d)\n", ctx->old_rtable->ref_count );
+ rt_stats( ctx->old_rtable );
+ } else {
+ rmr_vlog_force( RMR_VL_DEBUG, "old route table was empty\n" );
+ }
rmr_vlog_force( RMR_VL_DEBUG, "new route table:\n" );
rt_stats( ctx->rtable );
}
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "new table; dropping incomplete table\n" );
uta_rt_drop( ctx->new_rtable );
+ ctx->new_rtable = NULL;
}
if( ctx->table_id != NULL ) {
ctx->table_id = NULL;
}
- ctx->new_rtable = NULL;
- ctx->new_rtable = uta_rt_clone( ctx->rtable ); // create by cloning endpoint and meidtentries from active table
+ ctx->new_rtable = prep_new_rt( ctx, SOME ); // wait for old table to drain and shift it back to new
ctx->new_rtable->updates = 0; // init count of entries received
+
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "start of route table noticed\n" );
}
break;
}
if( ctx->new_rtable ) {
- uta_rt_drop( ctx->old_rtable ); // time to drop one that was previously replaced
- ctx->old_rtable = ctx->rtable; // currently active becomes old and allowed to 'drain'
- ctx->rtable = ctx->new_rtable; // one we've been adding to becomes active
- ctx->new_rtable = NULL;
+ roll_tables( ctx ); // roll active to old, and new to active with proper locking
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "end of rt update noticed\n" );
if( vlevel > 0 ) {
- rmr_vlog_force( RMR_VL_DEBUG, "old route table:\n" );
- rt_stats( ctx->old_rtable );
+ if( ctx->old_rtable != NULL ) {
+ rmr_vlog_force( RMR_VL_DEBUG, "old route table: (ref_count=%d)\n", ctx->old_rtable->ref_count );
+ rt_stats( ctx->old_rtable );
+ } else {
+ rmr_vlog_force( RMR_VL_DEBUG, "old route table was empty\n" );
+ }
rmr_vlog_force( RMR_VL_DEBUG, "updated route table:\n" );
rt_stats( ctx->rtable );
}
if( ctx->new_rtable != NULL ) { // one in progress? this forces it out
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "new table; dropping incomplete table\n" );
uta_rt_drop( ctx->new_rtable );
+ ctx->new_rtable = NULL;
}
- if( ntoks >2 ) {
+ if( ntoks > 2 ) {
if( ctx->table_id != NULL ) {
free( ctx->table_id );
}
ctx->table_id = strdup( clip( tokens[2] ) );
}
- ctx->new_rtable = uta_rt_clone_all( ctx->rtable ); // start with a clone of everything (endpts and entries)
- ctx->new_rtable->updates = 0; // init count of updates received
+ ctx->new_rtable = prep_new_rt( ctx, ALL ); // start with a copy of everything in the live table
+ ctx->new_rtable->updates = 0; // init count of updates received
+
if( DEBUG > 1 || (vlevel > 1) ) rmr_vlog_force( RMR_VL_DEBUG, "start of rt update noticed\n" );
}
break;
return buf;
}
+// --------------------- initialisation/creation ---------------------------------------------
/*
Create and initialise a route table; Returns a pointer to the table struct.
*/
-static route_table_t* uta_rt_init( ) {
+static route_table_t* uta_rt_init( uta_ctx_t* ctx ) {
route_table_t* rt;
+ if( ctx == NULL ) {
+ return NULL;
+ }
if( (rt = (route_table_t *) malloc( sizeof( route_table_t ) )) == NULL ) {
return NULL;
}
+
memset( rt, 0, sizeof( *rt ) );
if( (rt->hash = rmr_sym_alloc( RT_SIZE )) == NULL ) {
return NULL;
}
+ rt->gate = ctx->rtgate; // single mutex needed for all route tables
+ rt->ephash = ctx->ephash; // all route tables share a common endpoint hash
+ pthread_mutex_init( rt->gate, NULL );
+
return rt;
}
Space is the space in the old table to copy. Space 0 uses an integer key and
references rte structs. All other spaces use a string key and reference endpoints.
*/
-static route_table_t* rt_clone_space( route_table_t* srt, route_table_t* nrt, int space ) {
+static route_table_t* rt_clone_space( uta_ctx_t* ctx, route_table_t* srt, route_table_t* nrt, int space ) {
endpoint_t* ep; // an endpoint (ignore sonar complaint about const*)
rtable_ent_t* rte; // a route table entry (ignore sonar complaint about const*)
void* sst; // source symtab
int i;
int free_on_err = 0;
+ if( ctx == NULL ) {
+ return NULL;
+ }
if( nrt == NULL ) { // make a new table if needed
free_on_err = 1;
- nrt = uta_rt_init();
+ nrt = uta_rt_init( ctx );
if( nrt == NULL ) {
return NULL;
}
}
/*
- Creates a new route table and then clones the parts of the table which we must keep with each newrt|start.
- The endpoint and meid entries in the hash must be preserved.
-
- NOTE: The first call to rt_clone_space() will create the new table and subsequent
- calls operate on the new table. The return of subsequent calls can be safely
- ignored. There are some code analysers which will claim that there are memory
- leaks here; not true as they aren't understanding the logic, just looking at
- an ignored return value and assuming it's different than what was passed in.
+ Given a destination route table (drt), clone from the source (srt) into it.
+ If drt is nil, alloc a new one. If srt is nil, then nothing is done (except to
+ allocate the drt if that was nil too). If all is true (1), then we will clone both
+ the MT and the ME spaces; otherwise only the ME space is cloned.
*/
-static route_table_t* uta_rt_clone( route_table_t* srt ) {
+static route_table_t* uta_rt_clone( uta_ctx_t* ctx, route_table_t* srt, route_table_t* drt, int all ) {
endpoint_t* ep; // an endpoint
rtable_ent_t* rte; // a route table entry
- route_table_t* nrt = NULL; // new route table
int i;
+ if( ctx == NULL ) {
+ return NULL;
+ }
+ if( drt == NULL ) {
+ drt = uta_rt_init( ctx );
+ }
if( srt == NULL ) {
- return uta_rt_init(); // no source to clone, just return an empty table
+ return drt;
}
- nrt = rt_clone_space( srt, NULL, RT_NAME_SPACE ); // allocate a new one, add endpoint refs
- rt_clone_space( srt, nrt, RT_ME_SPACE ); // add meid refs to new
+ drt->ephash = ctx->ephash; // all rts reference the same EP symtab
+ rt_clone_space( ctx, srt, drt, RT_ME_SPACE );
+ if( all ) {
+ rt_clone_space( ctx, srt, drt, RT_MT_SPACE );
+ }
- return nrt;
+ return drt;
}
/*
- Creates a new route table and then clones _all_ of the given route table (references
- both endpoints AND the route table entries. Needed to support a partial update where
- some route table entries will not be deleted if not explicitly in the update and when
- we are adding/replacing meid references.
+ Prepares the "new" route table for populating. If the old_rtable is not nil, then
+ we wait for it's use count to reach 0. Then the table is cleared, and moved on the
+ context to be referenced by the new pointer; the old pointer is set to nil.
- NOTE see note in uta_rt_clone() as it applies here too.
+ If the old table doesn't exist, then a new table is created and the new pointer is
+ set to reference it.
*/
-static route_table_t* uta_rt_clone_all( route_table_t* srt ) {
- endpoint_t const* ep; // an endpoint
- rtable_ent_t const* rte; // a route table entry
- route_table_t* nrt = NULL; // new route table
- int i;
+static route_table_t* prep_new_rt( uta_ctx_t* ctx, int all ) {
+ int counter = 0;
+ route_table_t* rt;
- if( srt == NULL ) {
- return uta_rt_init(); // no source to clone, just return an empty table
+ if( ctx == NULL ) {
+ return NULL;
}
- nrt = rt_clone_space( srt, NULL, RT_MT_SPACE ); // create new, clone all spaces to it
- rt_clone_space( srt, nrt, RT_NAME_SPACE );
- rt_clone_space( srt, nrt, RT_ME_SPACE );
+ if( (rt = ctx->old_rtable) != NULL ) {
+ ctx->old_rtable = NULL;
+ while( rt->ref_count > 0 ) { // wait for all who are using to stop
+ if( counter++ > 1000 ) {
+ rmr_vlog( RMR_VL_WARN, "rt_prep_newrt: internal mishap, ref count on table seems wedged" );
+ break;
+ }
- return nrt;
+ usleep( 1000 ); // small sleep to yield the processer if that is needed
+ }
+
+ rmr_sym_clear( rt ); // clear all entries from the old table
+ } else {
+ rt = NULL;
+ }
+
+ rt = uta_rt_clone( ctx, ctx->rtable, rt, all ); // also sets the ephash pointer
+ rt->ref_count = 0; // take no chances; ensure it's 0!
+
+ return rt;
}
+
/*
Given a name, find the endpoint struct in the provided route table.
*/
static endpoint_t* uta_get_ep( route_table_t* rt, char const* ep_name ) {
- if( rt == NULL || rt->hash == NULL || ep_name == NULL || *ep_name == 0 ) {
+ if( rt == NULL || rt->ephash == NULL || ep_name == NULL || *ep_name == 0 ) {
return NULL;
}
- return rmr_sym_get( rt->hash, ep_name, 1 );
+ return rmr_sym_get( rt->ephash, ep_name, 1 );
}
/*
Drop the given route table. Purge all type 0 entries, then drop the symtab itself.
+ Does NOT destroy the gate as it's a common gate for ALL route tables.
*/
static void uta_rt_drop( route_table_t* rt ) {
if( rt == NULL ) {
pthread_mutex_init( &ep->gate, NULL ); // init with default attrs
memset( &ep->scounts[0], 0, sizeof( ep->scounts ) );
- rmr_sym_put( rt->hash, ep_name, 1, ep );
+ rmr_sym_put( rt->ephash, ep_name, 1, ep );
}
return ep;
return (endpoint_t *) rmr_sym_get( rt->hash, meid, RT_ME_SPACE );
}
+/*
+ This returns a pointer to the currently active route table and ups
+ the reference count so that the route table is not freed while it
+ is being used. The caller MUST call release_rt() when finished
+ with the pointer.
+
+ Care must be taken: the ctx->rtable pointer _could_ change during the time
+ between the release of the lock and the return. Therefore we MUST grab
+ the current pointer when we have the lock so that if it does we don't
+ return a pointer to the wrong table.
+
+ This will return NULL if there is no active table.
+*/
+static inline route_table_t* get_rt( uta_ctx_t* ctx ) {
+ route_table_t* rrt; // return value
+
+ if( ctx == NULL || ctx->rtable == NULL ) {
+ return NULL;
+ }
+
+ pthread_mutex_lock( ctx->rtgate ); // must hold lock to bump use
+ rrt = ctx->rtable; // must stash the pointer while we hold lock
+ rrt->ref_count++;
+ pthread_mutex_unlock( ctx->rtgate );
+
+ return rrt; // pointer we upped the count with
+}
+
+/*
+ This will "release" the route table by reducing the use counter
+ in the table. The table may not be freed until the counter reaches
+ 0, so it's imparative that the pointer be "released" when it is
+ fetched by get_rt(). Once the caller has released the table it
+ may not safely use the pointer that it had.
+*/
+static inline void release_rt( uta_ctx_t* ctx, route_table_t* rt ) {
+ if( ctx == NULL || rt == NULL ) {
+ return;
+ }
+
+ pthread_mutex_lock( ctx->rtgate ); // must hold lock
+ if( rt->ref_count > 0 ) { // something smells if it's already 0, don't do antyhing if it is
+ rt->ref_count--;
+ }
+ pthread_mutex_unlock( ctx->rtgate );
+}
#endif
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