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freebsd-nq/sys/netgraph/ng_base.c
Gleb Smirnoff ac5dd14182 Fix two races which happen when netgraph is restructuring: 
- Introduce ng_topo_mtx, a mutex to protect topology changes.
  - In ng_destroy_node() protect with ng_topo_mtx the process
    of checking and pointing at ng_deadnode. [1]
  - In ng_con_part2() check that our peer is not a ng_deadnode,
    and protect the check with ng_topo_mtx.
  - Add KASSERTs to ng_acquire_read/write, to make more
    understandible synopsis in case if called on ng_deadnode.

Reported by:	Roselyn Lee [1]
2005-11-02 15:23:47 +00:00

3658 lines
94 KiB
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/*
* ng_base.c
*/
/*-
* Copyright (c) 1996-1999 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Authors: Julian Elischer <julian@freebsd.org>
* Archie Cobbs <archie@freebsd.org>
*
* $FreeBSD$
* $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
*/
/*
* This file implements the base netgraph code.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ctype.h>
#include <sys/errno.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <net/netisr.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
MODULE_VERSION(netgraph, NG_ABI_VERSION);
/* List of all active nodes */
static LIST_HEAD(, ng_node) ng_nodelist;
static struct mtx ng_nodelist_mtx;
/* Mutex to protect topology events. */
static struct mtx ng_topo_mtx;
#ifdef NETGRAPH_DEBUG
static struct mtx ngq_mtx; /* protects the queue item list */
static SLIST_HEAD(, ng_node) ng_allnodes;
static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
static SLIST_HEAD(, ng_hook) ng_allhooks;
static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
static void ng_dumpitems(void);
static void ng_dumpnodes(void);
static void ng_dumphooks(void);
#endif /* NETGRAPH_DEBUG */
/*
* DEAD versions of the structures.
* In order to avoid races, it is sometimes neccesary to point
* at SOMETHING even though theoretically, the current entity is
* INVALID. Use these to avoid these races.
*/
struct ng_type ng_deadtype = {
NG_ABI_VERSION,
"dead",
NULL, /* modevent */
NULL, /* constructor */
NULL, /* rcvmsg */
NULL, /* shutdown */
NULL, /* newhook */
NULL, /* findhook */
NULL, /* connect */
NULL, /* rcvdata */
NULL, /* disconnect */
NULL, /* cmdlist */
};
struct ng_node ng_deadnode = {
"dead",
&ng_deadtype,
NGF_INVALID,
1, /* refs */
0, /* numhooks */
NULL, /* private */
0, /* ID */
LIST_HEAD_INITIALIZER(ng_deadnode.hooks),
{}, /* all_nodes list entry */
{}, /* id hashtable list entry */
{}, /* workqueue entry */
{ 0,
{}, /* should never use! (should hang) */
NULL,
&ng_deadnode.nd_input_queue.queue,
&ng_deadnode
},
#ifdef NETGRAPH_DEBUG
ND_MAGIC,
__FILE__,
__LINE__,
{NULL}
#endif /* NETGRAPH_DEBUG */
};
struct ng_hook ng_deadhook = {
"dead",
NULL, /* private */
HK_INVALID | HK_DEAD,
1, /* refs always >= 1 */
0, /* undefined data link type */
&ng_deadhook, /* Peer is self */
&ng_deadnode, /* attached to deadnode */
{}, /* hooks list */
NULL, /* override rcvmsg() */
NULL, /* override rcvdata() */
#ifdef NETGRAPH_DEBUG
HK_MAGIC,
__FILE__,
__LINE__,
{NULL}
#endif /* NETGRAPH_DEBUG */
};
/*
* END DEAD STRUCTURES
*/
/* List nodes with unallocated work */
static TAILQ_HEAD(, ng_node) ng_worklist = TAILQ_HEAD_INITIALIZER(ng_worklist);
static struct mtx ng_worklist_mtx; /* MUST LOCK NODE FIRST */
/* List of installed types */
static LIST_HEAD(, ng_type) ng_typelist;
static struct mtx ng_typelist_mtx;
/* Hash related definitions */
/* XXX Don't need to initialise them because it's a LIST */
#define NG_ID_HASH_SIZE 32 /* most systems wont need even this many */
static LIST_HEAD(, ng_node) ng_ID_hash[NG_ID_HASH_SIZE];
static struct mtx ng_idhash_mtx;
/* Method to find a node.. used twice so do it here */
#define NG_IDHASH_FN(ID) ((ID) % (NG_ID_HASH_SIZE))
#define NG_IDHASH_FIND(ID, node) \
do { \
mtx_assert(&ng_idhash_mtx, MA_OWNED); \
LIST_FOREACH(node, &ng_ID_hash[NG_IDHASH_FN(ID)], \
nd_idnodes) { \
if (NG_NODE_IS_VALID(node) \
&& (NG_NODE_ID(node) == ID)) { \
break; \
} \
} \
} while (0)
/* Internal functions */
static int ng_add_hook(node_p node, const char *name, hook_p * hookp);
static int ng_generic_msg(node_p here, item_p item, hook_p lasthook);
static ng_ID_t ng_decodeidname(const char *name);
static int ngb_mod_event(module_t mod, int event, void *data);
static void ng_worklist_remove(node_p node);
static void ngintr(void);
static int ng_apply_item(node_p node, item_p item, int rw);
static void ng_flush_input_queue(struct ng_queue * ngq);
static void ng_setisr(node_p node);
static node_p ng_ID2noderef(ng_ID_t ID);
static int ng_con_nodes(node_p node, const char *name, node_p node2,
const char *name2);
static void ng_con_part2(node_p node, hook_p hook, void *arg1, int arg2);
static void ng_con_part3(node_p node, hook_p hook, void *arg1, int arg2);
static int ng_mkpeer(node_p node, const char *name,
const char *name2, char *type);
/* imported , these used to be externally visible, some may go back */
void ng_destroy_hook(hook_p hook);
node_p ng_name2noderef(node_p node, const char *name);
int ng_path2noderef(node_p here, const char *path,
node_p *dest, hook_p *lasthook);
int ng_make_node(const char *type, node_p *nodepp);
int ng_path_parse(char *addr, char **node, char **path, char **hook);
void ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
void ng_unname(node_p node);
/* Our own netgraph malloc type */
MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook", "netgraph hook structures");
MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node", "netgraph node structures");
MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item", "netgraph item structures");
MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
/* Should not be visible outside this file */
#define _NG_ALLOC_HOOK(hook) \
MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
#define _NG_ALLOC_NODE(node) \
MALLOC(node, node_p, sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
#ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
/*
* In debug mode:
* In an attempt to help track reference count screwups
* we do not free objects back to the malloc system, but keep them
* in a local cache where we can examine them and keep information safely
* after they have been freed.
* We use this scheme for nodes and hooks, and to some extent for items.
*/
static __inline hook_p
ng_alloc_hook(void)
{
hook_p hook;
SLIST_ENTRY(ng_hook) temp;
mtx_lock(&ng_nodelist_mtx);
hook = LIST_FIRST(&ng_freehooks);
if (hook) {
LIST_REMOVE(hook, hk_hooks);
bcopy(&hook->hk_all, &temp, sizeof(temp));
bzero(hook, sizeof(struct ng_hook));
bcopy(&temp, &hook->hk_all, sizeof(temp));
mtx_unlock(&ng_nodelist_mtx);
hook->hk_magic = HK_MAGIC;
} else {
mtx_unlock(&ng_nodelist_mtx);
_NG_ALLOC_HOOK(hook);
if (hook) {
hook->hk_magic = HK_MAGIC;
mtx_lock(&ng_nodelist_mtx);
SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
mtx_unlock(&ng_nodelist_mtx);
}
}
return (hook);
}
static __inline node_p
ng_alloc_node(void)
{
node_p node;
SLIST_ENTRY(ng_node) temp;
mtx_lock(&ng_nodelist_mtx);
node = LIST_FIRST(&ng_freenodes);
if (node) {
LIST_REMOVE(node, nd_nodes);
bcopy(&node->nd_all, &temp, sizeof(temp));
bzero(node, sizeof(struct ng_node));
bcopy(&temp, &node->nd_all, sizeof(temp));
mtx_unlock(&ng_nodelist_mtx);
node->nd_magic = ND_MAGIC;
} else {
mtx_unlock(&ng_nodelist_mtx);
_NG_ALLOC_NODE(node);
if (node) {
node->nd_magic = ND_MAGIC;
mtx_lock(&ng_nodelist_mtx);
SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
mtx_unlock(&ng_nodelist_mtx);
}
}
return (node);
}
#define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
#define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
#define NG_FREE_HOOK(hook) \
do { \
mtx_lock(&ng_nodelist_mtx); \
LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks); \
hook->hk_magic = 0; \
mtx_unlock(&ng_nodelist_mtx); \
} while (0)
#define NG_FREE_NODE(node) \
do { \
mtx_lock(&ng_nodelist_mtx); \
LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes); \
node->nd_magic = 0; \
mtx_unlock(&ng_nodelist_mtx); \
} while (0)
#else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
#define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
#define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
#define NG_FREE_HOOK(hook) do { FREE((hook), M_NETGRAPH_HOOK); } while (0)
#define NG_FREE_NODE(node) do { FREE((node), M_NETGRAPH_NODE); } while (0)
#endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
/* Set this to kdb_enter("X") to catch all errors as they occur */
#ifndef TRAP_ERROR
#define TRAP_ERROR()
#endif
static ng_ID_t nextID = 1;
#ifdef INVARIANTS
#define CHECK_DATA_MBUF(m) do { \
struct mbuf *n; \
int total; \
\
M_ASSERTPKTHDR(m); \
for (total = 0, n = (m); n != NULL; n = n->m_next) { \
total += n->m_len; \
if (n->m_nextpkt != NULL) \
panic("%s: m_nextpkt", __func__); \
} \
\
if ((m)->m_pkthdr.len != total) { \
panic("%s: %d != %d", \
__func__, (m)->m_pkthdr.len, total); \
} \
} while (0)
#else
#define CHECK_DATA_MBUF(m)
#endif
/************************************************************************
Parse type definitions for generic messages
************************************************************************/
/* Handy structure parse type defining macro */
#define DEFINE_PARSE_STRUCT_TYPE(lo, up, args) \
static const struct ng_parse_struct_field \
ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args; \
static const struct ng_parse_type ng_generic_ ## lo ## _type = { \
&ng_parse_struct_type, \
&ng_ ## lo ## _type_fields \
}
DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
/* Get length of an array when the length is stored as a 32 bit
value immediately preceding the array -- as with struct namelist
and struct typelist. */
static int
ng_generic_list_getLength(const struct ng_parse_type *type,
const u_char *start, const u_char *buf)
{
return *((const u_int32_t *)(buf - 4));
}
/* Get length of the array of struct linkinfo inside a struct hooklist */
static int
ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
const u_char *start, const u_char *buf)
{
const struct hooklist *hl = (const struct hooklist *)start;
return hl->nodeinfo.hooks;
}
/* Array type for a variable length array of struct namelist */
static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
&ng_generic_nodeinfo_type,
&ng_generic_list_getLength
};
static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
&ng_parse_array_type,
&ng_nodeinfoarray_type_info
};
/* Array type for a variable length array of struct typelist */
static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
&ng_generic_typeinfo_type,
&ng_generic_list_getLength
};
static const struct ng_parse_type ng_generic_typeinfoarray_type = {
&ng_parse_array_type,
&ng_typeinfoarray_type_info
};
/* Array type for array of struct linkinfo in struct hooklist */
static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
&ng_generic_linkinfo_type,
&ng_generic_linkinfo_getLength
};
static const struct ng_parse_type ng_generic_linkinfo_array_type = {
&ng_parse_array_type,
&ng_generic_linkinfo_array_type_info
};
DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
(&ng_generic_nodeinfoarray_type));
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_generic_cmds[] = {
{
NGM_GENERIC_COOKIE,
NGM_SHUTDOWN,
"shutdown",
NULL,
NULL
},
{
NGM_GENERIC_COOKIE,
NGM_MKPEER,
"mkpeer",
&ng_generic_mkpeer_type,
NULL
},
{
NGM_GENERIC_COOKIE,
NGM_CONNECT,
"connect",
&ng_generic_connect_type,
NULL
},
{
NGM_GENERIC_COOKIE,
NGM_NAME,
"name",
&ng_generic_name_type,
NULL
},
{
NGM_GENERIC_COOKIE,
NGM_RMHOOK,
"rmhook",
&ng_generic_rmhook_type,
NULL
},
{
NGM_GENERIC_COOKIE,
NGM_NODEINFO,
"nodeinfo",
NULL,
&ng_generic_nodeinfo_type
},
{
NGM_GENERIC_COOKIE,
NGM_LISTHOOKS,
"listhooks",
NULL,
&ng_generic_hooklist_type
},
{
NGM_GENERIC_COOKIE,
NGM_LISTNAMES,
"listnames",
NULL,
&ng_generic_listnodes_type /* same as NGM_LISTNODES */
},
{
NGM_GENERIC_COOKIE,
NGM_LISTNODES,
"listnodes",
NULL,
&ng_generic_listnodes_type
},
{
NGM_GENERIC_COOKIE,
NGM_LISTTYPES,
"listtypes",
NULL,
&ng_generic_typeinfo_type
},
{
NGM_GENERIC_COOKIE,
NGM_TEXT_CONFIG,
"textconfig",
NULL,
&ng_parse_string_type
},
{
NGM_GENERIC_COOKIE,
NGM_TEXT_STATUS,
"textstatus",
NULL,
&ng_parse_string_type
},
{
NGM_GENERIC_COOKIE,
NGM_ASCII2BINARY,
"ascii2binary",
&ng_parse_ng_mesg_type,
&ng_parse_ng_mesg_type
},
{
NGM_GENERIC_COOKIE,
NGM_BINARY2ASCII,
"binary2ascii",
&ng_parse_ng_mesg_type,
&ng_parse_ng_mesg_type
},
{ 0 }
};
/************************************************************************
Node routines
************************************************************************/
/*
* Instantiate a node of the requested type
*/
int
ng_make_node(const char *typename, node_p *nodepp)
{
struct ng_type *type;
int error;
/* Check that the type makes sense */
if (typename == NULL) {
TRAP_ERROR();
return (EINVAL);
}
/* Locate the node type. If we fail we return. Do not try to load
* module.
*/
if ((type = ng_findtype(typename)) == NULL)
return (ENXIO);
/*
* If we have a constructor, then make the node and
* call the constructor to do type specific initialisation.
*/
if (type->constructor != NULL) {
if ((error = ng_make_node_common(type, nodepp)) == 0) {
if ((error = ((*type->constructor)(*nodepp)) != 0)) {
NG_NODE_UNREF(*nodepp);
}
}
} else {
/*
* Node has no constructor. We cannot ask for one
* to be made. It must be brought into existance by
* some external agency. The external agency should
* call ng_make_node_common() directly to get the
* netgraph part initialised.
*/
TRAP_ERROR();
error = EINVAL;
}
return (error);
}
/*
* Generic node creation. Called by node initialisation for externally
* instantiated nodes (e.g. hardware, sockets, etc ).
* The returned node has a reference count of 1.
*/
int
ng_make_node_common(struct ng_type *type, node_p *nodepp)
{
node_p node;
/* Require the node type to have been already installed */
if (ng_findtype(type->name) == NULL) {
TRAP_ERROR();
return (EINVAL);
}
/* Make a node and try attach it to the type */
NG_ALLOC_NODE(node);
if (node == NULL) {
TRAP_ERROR();
return (ENOMEM);
}
node->nd_type = type;
NG_NODE_REF(node); /* note reference */
type->refs++;
mtx_init(&node->nd_input_queue.q_mtx, "ng_node", NULL, MTX_SPIN);
node->nd_input_queue.queue = NULL;
node->nd_input_queue.last = &node->nd_input_queue.queue;
node->nd_input_queue.q_flags = 0;
node->nd_input_queue.q_node = node;
/* Initialize hook list for new node */
LIST_INIT(&node->nd_hooks);
/* Link us into the node linked list */
mtx_lock(&ng_nodelist_mtx);
LIST_INSERT_HEAD(&ng_nodelist, node, nd_nodes);
mtx_unlock(&ng_nodelist_mtx);
/* get an ID and put us in the hash chain */
mtx_lock(&ng_idhash_mtx);
for (;;) { /* wrap protection, even if silly */
node_p node2 = NULL;
node->nd_ID = nextID++; /* 137/second for 1 year before wrap */
/* Is there a problem with the new number? */
NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
if ((node->nd_ID != 0) && (node2 == NULL)) {
break;
}
}
LIST_INSERT_HEAD(&ng_ID_hash[NG_IDHASH_FN(node->nd_ID)],
node, nd_idnodes);
mtx_unlock(&ng_idhash_mtx);
/* Done */
*nodepp = node;
return (0);
}
/*
* Forceably start the shutdown process on a node. Either call
* it's shutdown method, or do the default shutdown if there is
* no type-specific method.
*
* We can only be called form a shutdown message, so we know we have
* a writer lock, and therefore exclusive access. It also means
* that we should not be on the work queue, but we check anyhow.
*
* Persistent node types must have a type-specific method which
* Allocates a new node in which case, this one is irretrievably going away,
* or cleans up anything it needs, and just makes the node valid again,
* in which case we allow the node to survive.
*
* XXX We need to think of how to tell a persistant node that we
* REALLY need to go away because the hardware has gone or we
* are rebooting.... etc.
*/
void
ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
{
hook_p hook;
/* Check if it's already shutting down */
if ((node->nd_flags & NGF_CLOSING) != 0)
return;
if (node == &ng_deadnode) {
printf ("shutdown called on deadnode\n");
return;
}
/* Add an extra reference so it doesn't go away during this */
NG_NODE_REF(node);
/*
* Mark it invalid so any newcomers know not to try use it
* Also add our own mark so we can't recurse
* note that NGF_INVALID does not do this as it's also set during
* creation
*/
node->nd_flags |= NGF_INVALID|NGF_CLOSING;
/* If node has its pre-shutdown method, then call it first*/
if (node->nd_type && node->nd_type->close)
(*node->nd_type->close)(node);
/* Notify all remaining connected nodes to disconnect */
while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
ng_destroy_hook(hook);
/*
* Drain the input queue forceably.
* it has no hooks so what's it going to do, bleed on someone?
* Theoretically we came here from a queue entry that was added
* Just before the queue was closed, so it should be empty anyway.
* Also removes us from worklist if needed.
*/
ng_flush_input_queue(&node->nd_input_queue);
/* Ask the type if it has anything to do in this case */
if (node->nd_type && node->nd_type->shutdown) {
(*node->nd_type->shutdown)(node);
if (NG_NODE_IS_VALID(node)) {
/*
* Well, blow me down if the node code hasn't declared
* that it doesn't want to die.
* Presumably it is a persistant node.
* If we REALLY want it to go away,
* e.g. hardware going away,
* Our caller should set NGF_REALLY_DIE in nd_flags.
*/
node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
NG_NODE_UNREF(node); /* Assume they still have theirs */
return;
}
} else { /* do the default thing */
NG_NODE_UNREF(node);
}
ng_unname(node); /* basically a NOP these days */
/*
* Remove extra reference, possibly the last
* Possible other holders of references may include
* timeout callouts, but theoretically the node's supposed to
* have cancelled them. Possibly hardware dependencies may
* force a driver to 'linger' with a reference.
*/
NG_NODE_UNREF(node);
}
#ifdef NETGRAPH_DEBUG
void
ng_ref_node(node_p node)
{
_NG_NODE_REF(node);
}
#endif
/*
* Remove a reference to the node, possibly the last.
* deadnode always acts as it it were the last.
*/
int
ng_unref_node(node_p node)
{
int v;
if (node == &ng_deadnode) {
return (0);
}
do {
v = node->nd_refs - 1;
} while (! atomic_cmpset_int(&node->nd_refs, v + 1, v));
if (v == 0) { /* we were the last */
mtx_lock(&ng_nodelist_mtx);
node->nd_type->refs--; /* XXX maybe should get types lock? */
LIST_REMOVE(node, nd_nodes);
mtx_unlock(&ng_nodelist_mtx);
mtx_lock(&ng_idhash_mtx);
LIST_REMOVE(node, nd_idnodes);
mtx_unlock(&ng_idhash_mtx);
mtx_destroy(&node->nd_input_queue.q_mtx);
NG_FREE_NODE(node);
}
return (v);
}
/************************************************************************
Node ID handling
************************************************************************/
static node_p
ng_ID2noderef(ng_ID_t ID)
{
node_p node;
mtx_lock(&ng_idhash_mtx);
NG_IDHASH_FIND(ID, node);
if(node)
NG_NODE_REF(node);
mtx_unlock(&ng_idhash_mtx);
return(node);
}
ng_ID_t
ng_node2ID(node_p node)
{
return (node ? NG_NODE_ID(node) : 0);
}
/************************************************************************
Node name handling
************************************************************************/
/*
* Assign a node a name. Once assigned, the name cannot be changed.
*/
int
ng_name_node(node_p node, const char *name)
{
int i;
node_p node2;
/* Check the name is valid */
for (i = 0; i < NG_NODESIZ; i++) {
if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
break;
}
if (i == 0 || name[i] != '\0') {
TRAP_ERROR();
return (EINVAL);
}
if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
TRAP_ERROR();
return (EINVAL);
}
/* Check the name isn't already being used */
if ((node2 = ng_name2noderef(node, name)) != NULL) {
NG_NODE_UNREF(node2);
TRAP_ERROR();
return (EADDRINUSE);
}
/* copy it */
strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
return (0);
}
/*
* Find a node by absolute name. The name should NOT end with ':'
* The name "." means "this node" and "[xxx]" means "the node
* with ID (ie, at address) xxx".
*
* Returns the node if found, else NULL.
* Eventually should add something faster than a sequential search.
* Note it aquires a reference on the node so you can be sure it's still there.
*/
node_p
ng_name2noderef(node_p here, const char *name)
{
node_p node;
ng_ID_t temp;
/* "." means "this node" */
if (strcmp(name, ".") == 0) {
NG_NODE_REF(here);
return(here);
}
/* Check for name-by-ID */
if ((temp = ng_decodeidname(name)) != 0) {
return (ng_ID2noderef(temp));
}
/* Find node by name */
mtx_lock(&ng_nodelist_mtx);
LIST_FOREACH(node, &ng_nodelist, nd_nodes) {
if (NG_NODE_IS_VALID(node)
&& NG_NODE_HAS_NAME(node)
&& (strcmp(NG_NODE_NAME(node), name) == 0)) {
break;
}
}
if (node)
NG_NODE_REF(node);
mtx_unlock(&ng_nodelist_mtx);
return (node);
}
/*
* Decode an ID name, eg. "[f03034de]". Returns 0 if the
* string is not valid, otherwise returns the value.
*/
static ng_ID_t
ng_decodeidname(const char *name)
{
const int len = strlen(name);
char *eptr;
u_long val;
/* Check for proper length, brackets, no leading junk */
if ((len < 3)
|| (name[0] != '[')
|| (name[len - 1] != ']')
|| (!isxdigit(name[1]))) {
return ((ng_ID_t)0);
}
/* Decode number */
val = strtoul(name + 1, &eptr, 16);
if ((eptr - name != len - 1)
|| (val == ULONG_MAX)
|| (val == 0)) {
return ((ng_ID_t)0);
}
return (ng_ID_t)val;
}
/*
* Remove a name from a node. This should only be called
* when shutting down and removing the node.
* IF we allow name changing this may be more resurected.
*/
void
ng_unname(node_p node)
{
}
/************************************************************************
Hook routines
Names are not optional. Hooks are always connected, except for a
brief moment within these routines. On invalidation or during creation
they are connected to the 'dead' hook.
************************************************************************/
/*
* Remove a hook reference
*/
void
ng_unref_hook(hook_p hook)
{
int v;
if (hook == &ng_deadhook) {
return;
}
do {
v = hook->hk_refs;
} while (! atomic_cmpset_int(&hook->hk_refs, v, v - 1));
if (v == 1) { /* we were the last */
if (_NG_HOOK_NODE(hook)) { /* it'll probably be ng_deadnode */
_NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
hook->hk_node = NULL;
}
NG_FREE_HOOK(hook);
}
}
/*
* Add an unconnected hook to a node. Only used internally.
* Assumes node is locked. (XXX not yet true )
*/
static int
ng_add_hook(node_p node, const char *name, hook_p *hookp)
{
hook_p hook;
int error = 0;
/* Check that the given name is good */
if (name == NULL) {
TRAP_ERROR();
return (EINVAL);
}
if (ng_findhook(node, name) != NULL) {
TRAP_ERROR();
return (EEXIST);
}
/* Allocate the hook and link it up */
NG_ALLOC_HOOK(hook);
if (hook == NULL) {
TRAP_ERROR();
return (ENOMEM);
}
hook->hk_refs = 1; /* add a reference for us to return */
hook->hk_flags = HK_INVALID;
hook->hk_peer = &ng_deadhook; /* start off this way */
hook->hk_node = node;
NG_NODE_REF(node); /* each hook counts as a reference */
/* Set hook name */
strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
/*
* Check if the node type code has something to say about it
* If it fails, the unref of the hook will also unref the node.
*/
if (node->nd_type->newhook != NULL) {
if ((error = (*node->nd_type->newhook)(node, hook, name))) {
NG_HOOK_UNREF(hook); /* this frees the hook */
return (error);
}
}
/*
* The 'type' agrees so far, so go ahead and link it in.
* We'll ask again later when we actually connect the hooks.
*/
LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
node->nd_numhooks++;
NG_HOOK_REF(hook); /* one for the node */
if (hookp)
*hookp = hook;
return (0);
}
/*
* Find a hook
*
* Node types may supply their own optimized routines for finding
* hooks. If none is supplied, we just do a linear search.
* XXX Possibly we should add a reference to the hook?
*/
hook_p
ng_findhook(node_p node, const char *name)
{
hook_p hook;
if (node->nd_type->findhook != NULL)
return (*node->nd_type->findhook)(node, name);
LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
if (NG_HOOK_IS_VALID(hook)
&& (strcmp(NG_HOOK_NAME(hook), name) == 0))
return (hook);
}
return (NULL);
}
/*
* Destroy a hook
*
* As hooks are always attached, this really destroys two hooks.
* The one given, and the one attached to it. Disconnect the hooks
* from each other first. We reconnect the peer hook to the 'dead'
* hook so that it can still exist after we depart. We then
* send the peer its own destroy message. This ensures that we only
* interact with the peer's structures when it is locked processing that
* message. We hold a reference to the peer hook so we are guaranteed that
* the peer hook and node are still going to exist until
* we are finished there as the hook holds a ref on the node.
* We run this same code again on the peer hook, but that time it is already
* attached to the 'dead' hook.
*
* This routine is called at all stages of hook creation
* on error detection and must be able to handle any such stage.
*/
void
ng_destroy_hook(hook_p hook)
{
hook_p peer;
node_p node;
if (hook == &ng_deadhook) { /* better safe than sorry */
printf("ng_destroy_hook called on deadhook\n");
return;
}
/*
* Protect divorce process with mutex, to avoid races on
* simultaneous disconnect.
*/
mtx_lock(&ng_topo_mtx);
hook->hk_flags |= HK_INVALID;
peer = NG_HOOK_PEER(hook);
node = NG_HOOK_NODE(hook);
if (peer && (peer != &ng_deadhook)) {
/*
* Set the peer to point to ng_deadhook
* from this moment on we are effectively independent it.
* send it an rmhook message of it's own.
*/
peer->hk_peer = &ng_deadhook; /* They no longer know us */
hook->hk_peer = &ng_deadhook; /* Nor us, them */
if (NG_HOOK_NODE(peer) == &ng_deadnode) {
/*
* If it's already divorced from a node,
* just free it.
*/
mtx_unlock(&ng_topo_mtx);
} else {
mtx_unlock(&ng_topo_mtx);
ng_rmhook_self(peer); /* Send it a surprise */
}
NG_HOOK_UNREF(peer); /* account for peer link */
NG_HOOK_UNREF(hook); /* account for peer link */
} else
mtx_unlock(&ng_topo_mtx);
mtx_assert(&ng_topo_mtx, MA_NOTOWNED);
/*
* Remove the hook from the node's list to avoid possible recursion
* in case the disconnection results in node shutdown.
*/
if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
return;
}
LIST_REMOVE(hook, hk_hooks);
node->nd_numhooks--;
if (node->nd_type->disconnect) {
/*
* The type handler may elect to destroy the node so don't
* trust its existance after this point. (except
* that we still hold a reference on it. (which we
* inherrited from the hook we are destroying)
*/
(*node->nd_type->disconnect) (hook);
}
/*
* Note that because we will point to ng_deadnode, the original node
* is not decremented automatically so we do that manually.
*/
_NG_HOOK_NODE(hook) = &ng_deadnode;
NG_NODE_UNREF(node); /* We no longer point to it so adjust count */
NG_HOOK_UNREF(hook); /* Account for linkage (in list) to node */
}
/*
* Take two hooks on a node and merge the connection so that the given node
* is effectively bypassed.
*/
int
ng_bypass(hook_p hook1, hook_p hook2)
{
if (hook1->hk_node != hook2->hk_node) {
TRAP_ERROR();
return (EINVAL);
}
hook1->hk_peer->hk_peer = hook2->hk_peer;
hook2->hk_peer->hk_peer = hook1->hk_peer;
hook1->hk_peer = &ng_deadhook;
hook2->hk_peer = &ng_deadhook;
/* XXX If we ever cache methods on hooks update them as well */
ng_destroy_hook(hook1);
ng_destroy_hook(hook2);
return (0);
}
/*
* Install a new netgraph type
*/
int
ng_newtype(struct ng_type *tp)
{
const size_t namelen = strlen(tp->name);
/* Check version and type name fields */
if ((tp->version != NG_ABI_VERSION)
|| (namelen == 0)
|| (namelen >= NG_TYPESIZ)) {
TRAP_ERROR();
if (tp->version != NG_ABI_VERSION) {
printf("Netgraph: Node type rejected. ABI mismatch. Suggest recompile\n");
}
return (EINVAL);
}
/* Check for name collision */
if (ng_findtype(tp->name) != NULL) {
TRAP_ERROR();
return (EEXIST);
}
/* Link in new type */
mtx_lock(&ng_typelist_mtx);
LIST_INSERT_HEAD(&ng_typelist, tp, types);
tp->refs = 1; /* first ref is linked list */
mtx_unlock(&ng_typelist_mtx);
return (0);
}
/*
* unlink a netgraph type
* If no examples exist
*/
int
ng_rmtype(struct ng_type *tp)
{
/* Check for name collision */
if (tp->refs != 1) {
TRAP_ERROR();
return (EBUSY);
}
/* Unlink type */
mtx_lock(&ng_typelist_mtx);
LIST_REMOVE(tp, types);
mtx_unlock(&ng_typelist_mtx);
return (0);
}
/*
* Look for a type of the name given
*/
struct ng_type *
ng_findtype(const char *typename)
{
struct ng_type *type;
mtx_lock(&ng_typelist_mtx);
LIST_FOREACH(type, &ng_typelist, types) {
if (strcmp(type->name, typename) == 0)
break;
}
mtx_unlock(&ng_typelist_mtx);
return (type);
}
/************************************************************************
Composite routines
************************************************************************/
/*
* Connect two nodes using the specified hooks, using queued functions.
*/
static void
ng_con_part3(node_p node, hook_p hook, void *arg1, int arg2)
{
/*
* When we run, we know that the node 'node' is locked for us.
* Our caller has a reference on the hook.
* Our caller has a reference on the node.
* (In this case our caller is ng_apply_item() ).
* The peer hook has a reference on the hook.
* We are all set up except for the final call to the node, and
* the clearing of the INVALID flag.
*/
if (NG_HOOK_NODE(hook) == &ng_deadnode) {
/*
* The node must have been freed again since we last visited
* here. ng_destry_hook() has this effect but nothing else does.
* We should just release our references and
* free anything we can think of.
* Since we know it's been destroyed, and it's our caller
* that holds the references, just return.
*/
return ;
}
if (hook->hk_node->nd_type->connect) {
if ((*hook->hk_node->nd_type->connect) (hook)) {
ng_destroy_hook(hook); /* also zaps peer */
printf("failed in ng_con_part3()\n");
return ;
}
}
/*
* XXX this is wrong for SMP. Possibly we need
* to separate out 'create' and 'invalid' flags.
* should only set flags on hooks we have locked under our node.
*/
hook->hk_flags &= ~HK_INVALID;
return ;
}
static void
ng_con_part2(node_p node, hook_p hook, void *arg1, int arg2)
{
hook_p peer;
/*
* When we run, we know that the node 'node' is locked for us.
* Our caller has a reference on the hook.
* Our caller has a reference on the node.
* (In this case our caller is ng_apply_item() ).
* The peer hook has a reference on the hook.
* our node pointer points to the 'dead' node.
* First check the hook name is unique.
* Should not happen because we checked before queueing this.
*/
if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
TRAP_ERROR();
ng_destroy_hook(hook); /* should destroy peer too */
printf("failed in ng_con_part2()\n");
return ;
}
/*
* Check if the node type code has something to say about it
* If it fails, the unref of the hook will also unref the attached node,
* however since that node is 'ng_deadnode' this will do nothing.
* The peer hook will also be destroyed.
*/
if (node->nd_type->newhook != NULL) {
if ((*node->nd_type->newhook)(node, hook, hook->hk_name)) {
ng_destroy_hook(hook); /* should destroy peer too */
printf("failed in ng_con_part2()\n");
return ;
}
}
/*
* The 'type' agrees so far, so go ahead and link it in.
* We'll ask again later when we actually connect the hooks.
*/
hook->hk_node = node; /* just overwrite ng_deadnode */
NG_NODE_REF(node); /* each hook counts as a reference */
LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
node->nd_numhooks++;
NG_HOOK_REF(hook); /* one for the node */
/*
* We now have a symetrical situation, where both hooks have been
* linked to their nodes, the newhook methods have been called
* And the references are all correct. The hooks are still marked
* as invalid, as we have not called the 'connect' methods
* yet.
* We can call the local one immediatly as we have the
* node locked, but we need to queue the remote one.
*/
if (hook->hk_node->nd_type->connect) {
if ((*hook->hk_node->nd_type->connect) (hook)) {
ng_destroy_hook(hook); /* also zaps peer */
printf("failed in ng_con_part2(A)\n");
return ;
}
}
/*
* Acquire topo mutex to avoid race with ng_destroy_hook().
*/
mtx_lock(&ng_topo_mtx);
peer = hook->hk_peer;
if (peer == &ng_deadhook) {
mtx_unlock(&ng_topo_mtx);
printf("failed in ng_con_part2(B)\n");
ng_destroy_hook(hook);
return ;
}
mtx_unlock(&ng_topo_mtx);
if (ng_send_fn(peer->hk_node, peer, &ng_con_part3, arg1, arg2)) {
printf("failed in ng_con_part2(C)\n");
ng_destroy_hook(hook); /* also zaps peer */
return ;
}
hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
return ;
}
/*
* Connect this node with another node. We assume that this node is
* currently locked, as we are only called from an NGM_CONNECT message.
*/
static int
ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
{
int error;
hook_p hook;
hook_p hook2;
if (ng_findhook(node2, name2) != NULL) {
return(EEXIST);
}
if ((error = ng_add_hook(node, name, &hook))) /* gives us a ref */
return (error);
/* Allocate the other hook and link it up */
NG_ALLOC_HOOK(hook2);
if (hook2 == NULL) {
TRAP_ERROR();
ng_destroy_hook(hook); /* XXX check ref counts so far */
NG_HOOK_UNREF(hook); /* including our ref */
return (ENOMEM);
}
hook2->hk_refs = 1; /* start with a reference for us. */
hook2->hk_flags = HK_INVALID;
hook2->hk_peer = hook; /* Link the two together */
hook->hk_peer = hook2;
NG_HOOK_REF(hook); /* Add a ref for the peer to each*/
NG_HOOK_REF(hook2);
hook2->hk_node = &ng_deadnode;
strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
/*
* Queue the function above.
* Procesing continues in that function in the lock context of
* the other node.
*/
ng_send_fn(node2, hook2, &ng_con_part2, NULL, 0);
NG_HOOK_UNREF(hook); /* Let each hook go if it wants to */
NG_HOOK_UNREF(hook2);
return (0);
}
/*
* Make a peer and connect.
* We assume that the local node is locked.
* The new node probably doesn't need a lock until
* it has a hook, because it cannot really have any work until then,
* but we should think about it a bit more.
*
* The problem may come if the other node also fires up
* some hardware or a timer or some other source of activation,
* also it may already get a command msg via it's ID.
*
* We could use the same method as ng_con_nodes() but we'd have
* to add ability to remove the node when failing. (Not hard, just
* make arg1 point to the node to remove).
* Unless of course we just ignore failure to connect and leave
* an unconnected node?
*/
static int
ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
{
node_p node2;
hook_p hook1;
hook_p hook2;
int error;
if ((error = ng_make_node(type, &node2))) {
return (error);
}
if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
ng_rmnode(node2, NULL, NULL, 0);
return (error);
}
if ((error = ng_add_hook(node2, name2, &hook2))) {
ng_rmnode(node2, NULL, NULL, 0);
ng_destroy_hook(hook1);
NG_HOOK_UNREF(hook1);
return (error);
}
/*
* Actually link the two hooks together.
*/
hook1->hk_peer = hook2;
hook2->hk_peer = hook1;
/* Each hook is referenced by the other */
NG_HOOK_REF(hook1);
NG_HOOK_REF(hook2);
/* Give each node the opportunity to veto the pending connection */
if (hook1->hk_node->nd_type->connect) {
error = (*hook1->hk_node->nd_type->connect) (hook1);
}
if ((error == 0) && hook2->hk_node->nd_type->connect) {
error = (*hook2->hk_node->nd_type->connect) (hook2);
}
/*
* drop the references we were holding on the two hooks.
*/
if (error) {
ng_destroy_hook(hook2); /* also zaps hook1 */
ng_rmnode(node2, NULL, NULL, 0);
} else {
/* As a last act, allow the hooks to be used */
hook1->hk_flags &= ~HK_INVALID;
hook2->hk_flags &= ~HK_INVALID;
}
NG_HOOK_UNREF(hook1);
NG_HOOK_UNREF(hook2);
return (error);
}
/************************************************************************
Utility routines to send self messages
************************************************************************/
/* Shut this node down as soon as everyone is clear of it */
/* Should add arg "immediatly" to jump the queue */
int
ng_rmnode_self(node_p node)
{
int error;
if (node == &ng_deadnode)
return (0);
node->nd_flags |= NGF_INVALID;
if (node->nd_flags & NGF_CLOSING)
return (0);
error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
return (error);
}
static void
ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
{
ng_destroy_hook(hook);
return ;
}
int
ng_rmhook_self(hook_p hook)
{
int error;
node_p node = NG_HOOK_NODE(hook);
if (node == &ng_deadnode)
return (0);
error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
return (error);
}
/***********************************************************************
* Parse and verify a string of the form: <NODE:><PATH>
*
* Such a string can refer to a specific node or a specific hook
* on a specific node, depending on how you look at it. In the
* latter case, the PATH component must not end in a dot.
*
* Both <NODE:> and <PATH> are optional. The <PATH> is a string
* of hook names separated by dots. This breaks out the original
* string, setting *nodep to "NODE" (or NULL if none) and *pathp
* to "PATH" (or NULL if degenerate). Also, *hookp will point to
* the final hook component of <PATH>, if any, otherwise NULL.
*
* This returns -1 if the path is malformed. The char ** are optional.
***********************************************************************/
int
ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
{
char *node, *path, *hook;
int k;
/*
* Extract absolute NODE, if any
*/
for (path = addr; *path && *path != ':'; path++);
if (*path) {
node = addr; /* Here's the NODE */
*path++ = '\0'; /* Here's the PATH */
/* Node name must not be empty */
if (!*node)
return -1;
/* A name of "." is OK; otherwise '.' not allowed */
if (strcmp(node, ".") != 0) {
for (k = 0; node[k]; k++)
if (node[k] == '.')
return -1;
}
} else {
node = NULL; /* No absolute NODE */
path = addr; /* Here's the PATH */
}
/* Snoop for illegal characters in PATH */
for (k = 0; path[k]; k++)
if (path[k] == ':')
return -1;
/* Check for no repeated dots in PATH */
for (k = 0; path[k]; k++)
if (path[k] == '.' && path[k + 1] == '.')
return -1;
/* Remove extra (degenerate) dots from beginning or end of PATH */
if (path[0] == '.')
path++;
if (*path && path[strlen(path) - 1] == '.')
path[strlen(path) - 1] = 0;
/* If PATH has a dot, then we're not talking about a hook */
if (*path) {
for (hook = path, k = 0; path[k]; k++)
if (path[k] == '.') {
hook = NULL;
break;
}
} else
path = hook = NULL;
/* Done */
if (nodep)
*nodep = node;
if (pathp)
*pathp = path;
if (hookp)
*hookp = hook;
return (0);
}
/*
* Given a path, which may be absolute or relative, and a starting node,
* return the destination node.
*/
int
ng_path2noderef(node_p here, const char *address,
node_p *destp, hook_p *lasthook)
{
char fullpath[NG_PATHSIZ];
char *nodename, *path, pbuf[2];
node_p node, oldnode;
char *cp;
hook_p hook = NULL;
/* Initialize */
if (destp == NULL) {
TRAP_ERROR();
return EINVAL;
}
*destp = NULL;
/* Make a writable copy of address for ng_path_parse() */
strncpy(fullpath, address, sizeof(fullpath) - 1);
fullpath[sizeof(fullpath) - 1] = '\0';
/* Parse out node and sequence of hooks */
if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
TRAP_ERROR();
return EINVAL;
}
if (path == NULL) {
pbuf[0] = '.'; /* Needs to be writable */
pbuf[1] = '\0';
path = pbuf;
}
/*
* For an absolute address, jump to the starting node.
* Note that this holds a reference on the node for us.
* Don't forget to drop the reference if we don't need it.
*/
if (nodename) {
node = ng_name2noderef(here, nodename);
if (node == NULL) {
TRAP_ERROR();
return (ENOENT);
}
} else {
if (here == NULL) {
TRAP_ERROR();
return (EINVAL);
}
node = here;
NG_NODE_REF(node);
}
/*
* Now follow the sequence of hooks
* XXX
* We actually cannot guarantee that the sequence
* is not being demolished as we crawl along it
* without extra-ordinary locking etc.
* So this is a bit dodgy to say the least.
* We can probably hold up some things by holding
* the nodelist mutex for the time of this
* crawl if we wanted.. At least that way we wouldn't have to
* worry about the nodes dissappearing, but the hooks would still
* be a problem.
*/
for (cp = path; node != NULL && *cp != '\0'; ) {
char *segment;
/*
* Break out the next path segment. Replace the dot we just
* found with a NUL; "cp" points to the next segment (or the
* NUL at the end).
*/
for (segment = cp; *cp != '\0'; cp++) {
if (*cp == '.') {
*cp++ = '\0';
break;
}
}
/* Empty segment */
if (*segment == '\0')
continue;
/* We have a segment, so look for a hook by that name */
hook = ng_findhook(node, segment);
/* Can't get there from here... */
if (hook == NULL
|| NG_HOOK_PEER(hook) == NULL
|| NG_HOOK_NOT_VALID(hook)
|| NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
TRAP_ERROR();
NG_NODE_UNREF(node);
#if 0
printf("hooknotvalid %s %s %d %d %d %d ",
path,
segment,
hook == NULL,
NG_HOOK_PEER(hook) == NULL,
NG_HOOK_NOT_VALID(hook),
NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook)));
#endif
return (ENOENT);
}
/*
* Hop on over to the next node
* XXX
* Big race conditions here as hooks and nodes go away
* *** Idea.. store an ng_ID_t in each hook and use that
* instead of the direct hook in this crawl?
*/
oldnode = node;
if ((node = NG_PEER_NODE(hook)))
NG_NODE_REF(node); /* XXX RACE */
NG_NODE_UNREF(oldnode); /* XXX another race */
if (NG_NODE_NOT_VALID(node)) {
NG_NODE_UNREF(node); /* XXX more races */
node = NULL;
}
}
/* If node somehow missing, fail here (probably this is not needed) */
if (node == NULL) {
TRAP_ERROR();
return (ENXIO);
}
/* Done */
*destp = node;
if (lasthook != NULL)
*lasthook = (hook ? NG_HOOK_PEER(hook) : NULL);
return (0);
}
/***************************************************************\
* Input queue handling.
* All activities are submitted to the node via the input queue
* which implements a multiple-reader/single-writer gate.
* Items which cannot be handled immeditly are queued.
*
* read-write queue locking inline functions *
\***************************************************************/
static __inline item_p ng_dequeue(struct ng_queue * ngq, int *rw);
static __inline item_p ng_acquire_read(struct ng_queue * ngq,
item_p item);
static __inline item_p ng_acquire_write(struct ng_queue * ngq,
item_p item);
static __inline void ng_leave_read(struct ng_queue * ngq);
static __inline void ng_leave_write(struct ng_queue * ngq);
static __inline void ng_queue_rw(struct ng_queue * ngq,
item_p item, int rw);
/*
* Definition of the bits fields in the ng_queue flag word.
* Defined here rather than in netgraph.h because no-one should fiddle
* with them.
*
* The ordering here may be important! don't shuffle these.
*/
/*-
Safety Barrier--------+ (adjustable to suit taste) (not used yet)
|
V
+-------+-------+-------+-------+-------+-------+-------+-------+
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |P|A|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |O|W|
+-------+-------+-------+-------+-------+-------+-------+-------+
\___________________________ ____________________________/ | |
V | |
[active reader count] | |
| |
Operation Pending -------------------------------+ |
|
Active Writer ---------------------------------------+
*/
#define WRITER_ACTIVE 0x00000001
#define OP_PENDING 0x00000002
#define READER_INCREMENT 0x00000004
#define READER_MASK 0xfffffffc /* Not valid if WRITER_ACTIVE is set */
#define SAFETY_BARRIER 0x00100000 /* 128K items queued should be enough */
/* Defines of more elaborate states on the queue */
/* Mask of bits a new read cares about */
#define NGQ_RMASK (WRITER_ACTIVE|OP_PENDING)
/* Mask of bits a new write cares about */
#define NGQ_WMASK (NGQ_RMASK|READER_MASK)
/* Test to decide if there is something on the queue. */
#define QUEUE_ACTIVE(QP) ((QP)->q_flags & OP_PENDING)
/* How to decide what the next queued item is. */
#define HEAD_IS_READER(QP) NGI_QUEUED_READER((QP)->queue)
#define HEAD_IS_WRITER(QP) NGI_QUEUED_WRITER((QP)->queue) /* notused */
/* Read the status to decide if the next item on the queue can now run. */
#define QUEUED_READER_CAN_PROCEED(QP) \
(((QP)->q_flags & (NGQ_RMASK & ~OP_PENDING)) == 0)
#define QUEUED_WRITER_CAN_PROCEED(QP) \
(((QP)->q_flags & (NGQ_WMASK & ~OP_PENDING)) == 0)
/* Is there a chance of getting ANY work off the queue? */
#define NEXT_QUEUED_ITEM_CAN_PROCEED(QP) \
(QUEUE_ACTIVE(QP) && \
((HEAD_IS_READER(QP)) ? QUEUED_READER_CAN_PROCEED(QP) : \
QUEUED_WRITER_CAN_PROCEED(QP)))
#define NGQRW_R 0
#define NGQRW_W 1
/*
* Taking into account the current state of the queue and node, possibly take
* the next entry off the queue and return it. Return NULL if there was
* nothing we could return, either because there really was nothing there, or
* because the node was in a state where it cannot yet process the next item
* on the queue.
*
* This MUST MUST MUST be called with the mutex held.
*/
static __inline item_p
ng_dequeue(struct ng_queue *ngq, int *rw)
{
item_p item;
u_int add_arg;
mtx_assert(&ngq->q_mtx, MA_OWNED);
/*
* If there is nothing queued, then just return.
* No point in continuing.
* XXXGL: assert this?
*/
if (!QUEUE_ACTIVE(ngq)) {
return (NULL);
}
/*
* From here, we can assume there is a head item.
* We need to find out what it is and if it can be dequeued, given
* the current state of the node.
*/
if (HEAD_IS_READER(ngq)) {
if (!QUEUED_READER_CAN_PROCEED(ngq)) {
/*
* It's a reader but we can't use it.
* We are stalled so make sure we don't
* get called again until something changes.
*/
ng_worklist_remove(ngq->q_node);
return (NULL);
}
/*
* Head of queue is a reader and we have no write active.
* We don't care how many readers are already active.
* Add the correct increment for the reader count.
*/
add_arg = READER_INCREMENT;
*rw = NGQRW_R;
} else if (QUEUED_WRITER_CAN_PROCEED(ngq)) {
/*
* There is a pending write, no readers and no active writer.
* This means we can go ahead with the pending writer. Note
* the fact that we now have a writer, ready for when we take
* it off the queue.
*
* We don't need to worry about a possible collision with the
* fasttrack reader.
*
* The fasttrack thread may take a long time to discover that we
* are running so we would have an inconsistent state in the
* flags for a while. Since we ignore the reader count
* entirely when the WRITER_ACTIVE flag is set, this should
* not matter (in fact it is defined that way). If it tests
* the flag before this operation, the OP_PENDING flag
* will make it fail, and if it tests it later, the
* WRITER_ACTIVE flag will do the same. If it is SO slow that
* we have actually completed the operation, and neither flag
* is set by the time that it tests the flags, then it is
* actually ok for it to continue. If it completes and we've
* finished and the read pending is set it still fails.
*
* So we can just ignore it, as long as we can ensure that the
* transition from WRITE_PENDING state to the WRITER_ACTIVE
* state is atomic.
*
* After failing, first it will be held back by the mutex, then
* when it can proceed, it will queue its request, then it
* would arrive at this function. Usually it will have to
* leave empty handed because the ACTIVE WRITER bit will be
* set.
*
* Adjust the flags for the new active writer.
*/
add_arg = WRITER_ACTIVE;
*rw = NGQRW_W;
/*
* We want to write "active writer, no readers " Now go make
* it true. In fact there may be a number in the readers
* count but we know it is not true and will be fixed soon.
* We will fix the flags for the next pending entry in a
* moment.
*/
} else {
/*
* We can't dequeue anything.. return and say so. Probably we
* have a write pending and the readers count is non zero. If
* we got here because a reader hit us just at the wrong
* moment with the fasttrack code, and put us in a strange
* state, then it will be coming through in just a moment,
* (just as soon as we release the mutex) and keep things
* moving.
* Make sure we remove ourselves from the work queue. It
* would be a waste of effort to do all this again.
*/
ng_worklist_remove(ngq->q_node);
return (NULL);
}
/*
* Now we dequeue the request (whatever it may be) and correct the
* pending flags and the next and last pointers.
*/
item = ngq->queue;
ngq->queue = item->el_next;
if (ngq->last == &(item->el_next)) {
/*
* that was the last entry in the queue so set the 'last
* pointer up correctly and make sure the pending flag is
* clear.
*/
add_arg += -OP_PENDING;
ngq->last = &(ngq->queue);
/*
* Whatever flag was set will be cleared and
* the new acive field will be set by the add as well,
* so we don't need to change add_arg.
* But we know we don't need to be on the work list.
*/
atomic_add_long(&ngq->q_flags, add_arg);
ng_worklist_remove(ngq->q_node);
} else {
/*
* Since there is still something on the queue
* we don't need to change the PENDING flag.
*/
atomic_add_long(&ngq->q_flags, add_arg);
/*
* If we see more doable work, make sure we are
* on the work queue.
*/
if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq)) {
ng_setisr(ngq->q_node);
}
}
return (item);
}
/*
* Queue a packet to be picked up by someone else.
* We really don't care who, but we can't or don't want to hang around
* to process it ourselves. We are probably an interrupt routine..
* If the queue could be run, flag the netisr handler to start.
*/
static __inline void
ng_queue_rw(struct ng_queue * ngq, item_p item, int rw)
{
mtx_assert(&ngq->q_mtx, MA_OWNED);
if (rw == NGQRW_W)
NGI_SET_WRITER(item);
else
NGI_SET_READER(item);
item->el_next = NULL; /* maybe not needed */
*ngq->last = item;
/*
* If it was the first item in the queue then we need to
* set the last pointer and the type flags.
*/
if (ngq->last == &(ngq->queue))
atomic_add_long(&ngq->q_flags, OP_PENDING);
ngq->last = &(item->el_next);
/*
* We can take the worklist lock with the node locked
* BUT NOT THE REVERSE!
*/
if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
ng_setisr(ngq->q_node);
}
/*
* This function 'cheats' in that it first tries to 'grab' the use of the
* node, without going through the mutex. We can do this becasue of the
* semantics of the lock. The semantics include a clause that says that the
* value of the readers count is invalid if the WRITER_ACTIVE flag is set. It
* also says that the WRITER_ACTIVE flag cannot be set if the readers count
* is not zero. Note that this talks about what is valid to SET the
* WRITER_ACTIVE flag, because from the moment it is set, the value if the
* reader count is immaterial, and not valid. The two 'pending' flags have a
* similar effect, in that If they are orthogonal to the two active fields in
* how they are set, but if either is set, the attempted 'grab' need to be
* backed out because there is earlier work, and we maintain ordering in the
* queue. The result of this is that the reader request can try obtain use of
* the node with only a single atomic addition, and without any of the mutex
* overhead. If this fails the operation degenerates to the same as for other
* cases.
*
*/
static __inline item_p
ng_acquire_read(struct ng_queue *ngq, item_p item)
{
KASSERT(ngq != &ng_deadnode.nd_input_queue,
("%s: working on deadnode", __func__));
/* ######### Hack alert ######### */
atomic_add_long(&ngq->q_flags, READER_INCREMENT);
if ((ngq->q_flags & NGQ_RMASK) == 0) {
/* Successfully grabbed node */
return (item);
}
/* undo the damage if we didn't succeed */
atomic_subtract_long(&ngq->q_flags, READER_INCREMENT);
/* ######### End Hack alert ######### */
mtx_lock_spin((&ngq->q_mtx));
/*
* Try again. Another processor (or interrupt for that matter) may
* have removed the last queued item that was stopping us from
* running, between the previous test, and the moment that we took
* the mutex. (Or maybe a writer completed.)
* Even if another fast-track reader hits during this period
* we don't care as multiple readers is OK.
*/
if ((ngq->q_flags & NGQ_RMASK) == 0) {
atomic_add_long(&ngq->q_flags, READER_INCREMENT);
mtx_unlock_spin((&ngq->q_mtx));
return (item);
}
/*
* and queue the request for later.
*/
ng_queue_rw(ngq, item, NGQRW_R);
mtx_unlock_spin(&(ngq->q_mtx));
return (NULL);
}
static __inline item_p
ng_acquire_write(struct ng_queue *ngq, item_p item)
{
KASSERT(ngq != &ng_deadnode.nd_input_queue,
("%s: working on deadnode", __func__));
restart:
mtx_lock_spin(&(ngq->q_mtx));
/*
* If there are no readers, no writer, and no pending packets, then
* we can just go ahead. In all other situations we need to queue the
* request
*/
if ((ngq->q_flags & NGQ_WMASK) == 0) {
/* collision could happen *HERE* */
atomic_add_long(&ngq->q_flags, WRITER_ACTIVE);
mtx_unlock_spin((&ngq->q_mtx));
if (ngq->q_flags & READER_MASK) {
/* Collision with fast-track reader */
atomic_subtract_long(&ngq->q_flags, WRITER_ACTIVE);
goto restart;
}
return (item);
}
/*
* and queue the request for later.
*/
ng_queue_rw(ngq, item, NGQRW_W);
mtx_unlock_spin(&(ngq->q_mtx));
return (NULL);
}
static __inline void
ng_leave_read(struct ng_queue *ngq)
{
atomic_subtract_long(&ngq->q_flags, READER_INCREMENT);
}
static __inline void
ng_leave_write(struct ng_queue *ngq)
{
atomic_subtract_long(&ngq->q_flags, WRITER_ACTIVE);
}
static void
ng_flush_input_queue(struct ng_queue * ngq)
{
item_p item;
mtx_lock_spin(&ngq->q_mtx);
while (ngq->queue) {
item = ngq->queue;
ngq->queue = item->el_next;
if (ngq->last == &(item->el_next)) {
ngq->last = &(ngq->queue);
atomic_add_long(&ngq->q_flags, -OP_PENDING);
}
mtx_unlock_spin(&ngq->q_mtx);
/* If the item is supplying a callback, call it with an error */
if (item->apply != NULL) {
(item->apply)(item->context, ENOENT);
item->apply = NULL;
}
NG_FREE_ITEM(item);
mtx_lock_spin(&ngq->q_mtx);
}
/*
* Take us off the work queue if we are there.
* We definatly have no work to be done.
*/
ng_worklist_remove(ngq->q_node);
mtx_unlock_spin(&ngq->q_mtx);
}
/***********************************************************************
* Externally visible method for sending or queueing messages or data.
***********************************************************************/
/*
* The module code should have filled out the item correctly by this stage:
* Common:
* reference to destination node.
* Reference to destination rcv hook if relevant.
* Data:
* pointer to mbuf
* Control_Message:
* pointer to msg.
* ID of original sender node. (return address)
* Function:
* Function pointer
* void * argument
* integer argument
*
* The nodes have several routines and macros to help with this task:
*/
int
ng_snd_item(item_p item, int flags)
{
hook_p hook = NGI_HOOK(item);
node_p node = NGI_NODE(item);
int queue, rw;
struct ng_queue * ngq = &node->nd_input_queue;
int error = 0;
#ifdef NETGRAPH_DEBUG
_ngi_check(item, __FILE__, __LINE__);
#endif
queue = (flags & NG_QUEUE) ? 1 : 0;
if (item == NULL) {
TRAP_ERROR();
return (EINVAL); /* failed to get queue element */
}
if (node == NULL) {
NG_FREE_ITEM(item);
TRAP_ERROR();
return (EINVAL); /* No address */
}
switch(item->el_flags & NGQF_TYPE) {
case NGQF_DATA:
/*
* DATA MESSAGE
* Delivered to a node via a non-optional hook.
* Both should be present in the item even though
* the node is derivable from the hook.
* References are held on both by the item.
*/
/* Protect nodes from sending NULL pointers
* to each other
*/
if (NGI_M(item) == NULL)
return (EINVAL);
CHECK_DATA_MBUF(NGI_M(item));
if (hook == NULL) {
NG_FREE_ITEM(item);
TRAP_ERROR();
return(EINVAL);
}
if ((NG_HOOK_NOT_VALID(hook))
|| (NG_NODE_NOT_VALID(NG_HOOK_NODE(hook)))) {
NG_FREE_ITEM(item);
return (ENOTCONN);
}
if ((hook->hk_flags & HK_QUEUE)) {
queue = 1;
}
break;
case NGQF_MESG:
/*
* CONTROL MESSAGE
* Delivered to a node.
* Hook is optional.
* References are held by the item on the node and
* the hook if it is present.
*/
if (hook && (hook->hk_flags & HK_QUEUE)) {
queue = 1;
}
break;
case NGQF_FN:
break;
default:
NG_FREE_ITEM(item);
TRAP_ERROR();
return (EINVAL);
}
switch(item->el_flags & NGQF_RW) {
case NGQF_READER:
rw = NGQRW_R;
break;
case NGQF_WRITER:
rw = NGQRW_W;
break;
default:
panic("%s: invalid item flags %lx", __func__, item->el_flags);
}
/*
* If the node specifies single threading, force writer semantics.
* Similarly, the node may say one hook always produces writers.
* These are overrides.
*/
if ((node->nd_flags & NGF_FORCE_WRITER)
|| (hook && (hook->hk_flags & HK_FORCE_WRITER)))
rw = NGQRW_W;
if (queue) {
/* Put it on the queue for that node*/
#ifdef NETGRAPH_DEBUG
_ngi_check(item, __FILE__, __LINE__);
#endif
mtx_lock_spin(&(ngq->q_mtx));
ng_queue_rw(ngq, item, rw);
mtx_unlock_spin(&(ngq->q_mtx));
if (flags & NG_PROGRESS)
return (EINPROGRESS);
else
return (0);
}
/*
* We already decided how we will be queueud or treated.
* Try get the appropriate operating permission.
*/
if (rw == NGQRW_R)
item = ng_acquire_read(ngq, item);
else
item = ng_acquire_write(ngq, item);
if (item == NULL) {
if (flags & NG_PROGRESS)
return (EINPROGRESS);
else
return (0);
}
#ifdef NETGRAPH_DEBUG
_ngi_check(item, __FILE__, __LINE__);
#endif
NGI_GET_NODE(item, node); /* zaps stored node */
error = ng_apply_item(node, item, rw); /* drops r/w lock when done */
/*
* If the node goes away when we remove the reference,
* whatever we just did caused it.. whatever we do, DO NOT
* access the node again!
*/
if (NG_NODE_UNREF(node) == 0) {
return (error);
}
mtx_lock_spin(&(ngq->q_mtx));
if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
ng_setisr(ngq->q_node);
mtx_unlock_spin(&(ngq->q_mtx));
return (error);
}
/*
* We have an item that was possibly queued somewhere.
* It should contain all the information needed
* to run it on the appropriate node/hook.
*/
static int
ng_apply_item(node_p node, item_p item, int rw)
{
hook_p hook;
int error = 0;
ng_rcvdata_t *rcvdata;
ng_rcvmsg_t *rcvmsg;
ng_apply_t *apply = NULL;
void *context = NULL;
NGI_GET_HOOK(item, hook); /* clears stored hook */
#ifdef NETGRAPH_DEBUG
_ngi_check(item, __FILE__, __LINE__);
#endif
/*
* If the item has an "apply" callback, store it.
* Clear item's callback immediately, to avoid an extra call if
* the item is reused by the destination node.
*/
if (item->apply != NULL) {
apply = item->apply;
context = item->context;
item->apply = NULL;
}
switch (item->el_flags & NGQF_TYPE) {
case NGQF_DATA:
/*
* Check things are still ok as when we were queued.
*/
if ((hook == NULL)
|| NG_HOOK_NOT_VALID(hook)
|| NG_NODE_NOT_VALID(node) ) {
error = EIO;
NG_FREE_ITEM(item);
break;
}
/*
* If no receive method, just silently drop it.
* Give preference to the hook over-ride method
*/
if ((!(rcvdata = hook->hk_rcvdata))
&& (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
error = 0;
NG_FREE_ITEM(item);
break;
}
error = (*rcvdata)(hook, item);
break;
case NGQF_MESG:
if (hook) {
if (NG_HOOK_NOT_VALID(hook)) {
/*
* The hook has been zapped then we can't
* use it. Immediatly drop its reference.
* The message may not need it.
*/
NG_HOOK_UNREF(hook);
hook = NULL;
}
}
/*
* Similarly, if the node is a zombie there is
* nothing we can do with it, drop everything.
*/
if (NG_NODE_NOT_VALID(node)) {
TRAP_ERROR();
error = EINVAL;
NG_FREE_ITEM(item);
} else {
/*
* Call the appropriate message handler for the object.
* It is up to the message handler to free the message.
* If it's a generic message, handle it generically,
* otherwise call the type's message handler
* (if it exists)
* XXX (race). Remember that a queued message may
* reference a node or hook that has just been
* invalidated. It will exist as the queue code
* is holding a reference, but..
*/
struct ng_mesg *msg = NGI_MSG(item);
/*
* check if the generic handler owns it.
*/
if ((msg->header.typecookie == NGM_GENERIC_COOKIE)
&& ((msg->header.flags & NGF_RESP) == 0)) {
error = ng_generic_msg(node, item, hook);
break;
}
/*
* Now see if there is a handler (hook or node specific)
* in the target node. If none, silently discard.
*/
if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg)))
&& (!(rcvmsg = node->nd_type->rcvmsg))) {
TRAP_ERROR();
error = 0;
NG_FREE_ITEM(item);
break;
}
error = (*rcvmsg)(node, item, hook);
}
break;
case NGQF_FN:
/*
* We have to implicitly trust the hook,
* as some of these are used for system purposes
* where the hook is invalid. In the case of
* the shutdown message we allow it to hit
* even if the node is invalid.
*/
if ((NG_NODE_NOT_VALID(node))
&& (NGI_FN(item) != &ng_rmnode)) {
TRAP_ERROR();
error = EINVAL;
NG_FREE_ITEM(item);
break;
}
(*NGI_FN(item))(node, hook, NGI_ARG1(item), NGI_ARG2(item));
NG_FREE_ITEM(item);
break;
}
/*
* We held references on some of the resources
* that we took from the item. Now that we have
* finished doing everything, drop those references.
*/
if (hook) {
NG_HOOK_UNREF(hook);
}
if (rw == NGQRW_R) {
ng_leave_read(&node->nd_input_queue);
} else {
ng_leave_write(&node->nd_input_queue);
}
/* Apply callback. */
if (apply != NULL)
(*apply)(context, error);
return (error);
}
/***********************************************************************
* Implement the 'generic' control messages
***********************************************************************/
static int
ng_generic_msg(node_p here, item_p item, hook_p lasthook)
{
int error = 0;
struct ng_mesg *msg;
struct ng_mesg *resp = NULL;
NGI_GET_MSG(item, msg);
if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
TRAP_ERROR();
error = EINVAL;
goto out;
}
switch (msg->header.cmd) {
case NGM_SHUTDOWN:
ng_rmnode(here, NULL, NULL, 0);
break;
case NGM_MKPEER:
{
struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
if (msg->header.arglen != sizeof(*mkp)) {
TRAP_ERROR();
error = EINVAL;
break;
}
mkp->type[sizeof(mkp->type) - 1] = '\0';
mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
break;
}
case NGM_CONNECT:
{
struct ngm_connect *const con =
(struct ngm_connect *) msg->data;
node_p node2;
if (msg->header.arglen != sizeof(*con)) {
TRAP_ERROR();
error = EINVAL;
break;
}
con->path[sizeof(con->path) - 1] = '\0';
con->ourhook[sizeof(con->ourhook) - 1] = '\0';
con->peerhook[sizeof(con->peerhook) - 1] = '\0';
/* Don't forget we get a reference.. */
error = ng_path2noderef(here, con->path, &node2, NULL);
if (error)
break;
error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
NG_NODE_UNREF(node2);
break;
}
case NGM_NAME:
{
struct ngm_name *const nam = (struct ngm_name *) msg->data;
if (msg->header.arglen != sizeof(*nam)) {
TRAP_ERROR();
error = EINVAL;
break;
}
nam->name[sizeof(nam->name) - 1] = '\0';
error = ng_name_node(here, nam->name);
break;
}
case NGM_RMHOOK:
{
struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
hook_p hook;
if (msg->header.arglen != sizeof(*rmh)) {
TRAP_ERROR();
error = EINVAL;
break;
}
rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
ng_destroy_hook(hook);
break;
}
case NGM_NODEINFO:
{
struct nodeinfo *ni;
NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
/* Fill in node info */
ni = (struct nodeinfo *) resp->data;
if (NG_NODE_HAS_NAME(here))
strcpy(ni->name, NG_NODE_NAME(here));
strcpy(ni->type, here->nd_type->name);
ni->id = ng_node2ID(here);
ni->hooks = here->nd_numhooks;
break;
}
case NGM_LISTHOOKS:
{
const int nhooks = here->nd_numhooks;
struct hooklist *hl;
struct nodeinfo *ni;
hook_p hook;
/* Get response struct */
NG_MKRESPONSE(resp, msg, sizeof(*hl)
+ (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
hl = (struct hooklist *) resp->data;
ni = &hl->nodeinfo;
/* Fill in node info */
if (NG_NODE_HAS_NAME(here))
strcpy(ni->name, NG_NODE_NAME(here));
strcpy(ni->type, here->nd_type->name);
ni->id = ng_node2ID(here);
/* Cycle through the linked list of hooks */
ni->hooks = 0;
LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
struct linkinfo *const link = &hl->link[ni->hooks];
if (ni->hooks >= nhooks) {
log(LOG_ERR, "%s: number of %s changed\n",
__func__, "hooks");
break;
}
if (NG_HOOK_NOT_VALID(hook))
continue;
strcpy(link->ourhook, NG_HOOK_NAME(hook));
strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
if (NG_PEER_NODE_NAME(hook)[0] != '\0')
strcpy(link->nodeinfo.name,
NG_PEER_NODE_NAME(hook));
strcpy(link->nodeinfo.type,
NG_PEER_NODE(hook)->nd_type->name);
link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
ni->hooks++;
}
break;
}
case NGM_LISTNAMES:
case NGM_LISTNODES:
{
const int unnamed = (msg->header.cmd == NGM_LISTNODES);
struct namelist *nl;
node_p node;
int num = 0;
mtx_lock(&ng_nodelist_mtx);
/* Count number of nodes */
LIST_FOREACH(node, &ng_nodelist, nd_nodes) {
if (NG_NODE_IS_VALID(node)
&& (unnamed || NG_NODE_HAS_NAME(node))) {
num++;
}
}
mtx_unlock(&ng_nodelist_mtx);
/* Get response struct */
NG_MKRESPONSE(resp, msg, sizeof(*nl)
+ (num * sizeof(struct nodeinfo)), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
nl = (struct namelist *) resp->data;
/* Cycle through the linked list of nodes */
nl->numnames = 0;
mtx_lock(&ng_nodelist_mtx);
LIST_FOREACH(node, &ng_nodelist, nd_nodes) {
struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
if (nl->numnames >= num) {
log(LOG_ERR, "%s: number of %s changed\n",
__func__, "nodes");
break;
}
if (NG_NODE_NOT_VALID(node))
continue;
if (!unnamed && (! NG_NODE_HAS_NAME(node)))
continue;
if (NG_NODE_HAS_NAME(node))
strcpy(np->name, NG_NODE_NAME(node));
strcpy(np->type, node->nd_type->name);
np->id = ng_node2ID(node);
np->hooks = node->nd_numhooks;
nl->numnames++;
}
mtx_unlock(&ng_nodelist_mtx);
break;
}
case NGM_LISTTYPES:
{
struct typelist *tl;
struct ng_type *type;
int num = 0;
mtx_lock(&ng_typelist_mtx);
/* Count number of types */
LIST_FOREACH(type, &ng_typelist, types) {
num++;
}
mtx_unlock(&ng_typelist_mtx);
/* Get response struct */
NG_MKRESPONSE(resp, msg, sizeof(*tl)
+ (num * sizeof(struct typeinfo)), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
tl = (struct typelist *) resp->data;
/* Cycle through the linked list of types */
tl->numtypes = 0;
mtx_lock(&ng_typelist_mtx);
LIST_FOREACH(type, &ng_typelist, types) {
struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
if (tl->numtypes >= num) {
log(LOG_ERR, "%s: number of %s changed\n",
__func__, "types");
break;
}
strcpy(tp->type_name, type->name);
tp->numnodes = type->refs - 1; /* don't count list */
tl->numtypes++;
}
mtx_unlock(&ng_typelist_mtx);
break;
}
case NGM_BINARY2ASCII:
{
int bufSize = 20 * 1024; /* XXX hard coded constant */
const struct ng_parse_type *argstype;
const struct ng_cmdlist *c;
struct ng_mesg *binary, *ascii;
/* Data area must contain a valid netgraph message */
binary = (struct ng_mesg *)msg->data;
if (msg->header.arglen < sizeof(struct ng_mesg)
|| (msg->header.arglen - sizeof(struct ng_mesg)
< binary->header.arglen)) {
TRAP_ERROR();
error = EINVAL;
break;
}
/* Get a response message with lots of room */
NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
ascii = (struct ng_mesg *)resp->data;
/* Copy binary message header to response message payload */
bcopy(binary, ascii, sizeof(*binary));
/* Find command by matching typecookie and command number */
for (c = here->nd_type->cmdlist;
c != NULL && c->name != NULL; c++) {
if (binary->header.typecookie == c->cookie
&& binary->header.cmd == c->cmd)
break;
}
if (c == NULL || c->name == NULL) {
for (c = ng_generic_cmds; c->name != NULL; c++) {
if (binary->header.typecookie == c->cookie
&& binary->header.cmd == c->cmd)
break;
}
if (c->name == NULL) {
NG_FREE_MSG(resp);
error = ENOSYS;
break;
}
}
/* Convert command name to ASCII */
snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
"%s", c->name);
/* Convert command arguments to ASCII */
argstype = (binary->header.flags & NGF_RESP) ?
c->respType : c->mesgType;
if (argstype == NULL) {
*ascii->data = '\0';
} else {
if ((error = ng_unparse(argstype,
(u_char *)binary->data,
ascii->data, bufSize)) != 0) {
NG_FREE_MSG(resp);
break;
}
}
/* Return the result as struct ng_mesg plus ASCII string */
bufSize = strlen(ascii->data) + 1;
ascii->header.arglen = bufSize;
resp->header.arglen = sizeof(*ascii) + bufSize;
break;
}
case NGM_ASCII2BINARY:
{
int bufSize = 2000; /* XXX hard coded constant */
const struct ng_cmdlist *c;
const struct ng_parse_type *argstype;
struct ng_mesg *ascii, *binary;
int off = 0;
/* Data area must contain at least a struct ng_mesg + '\0' */
ascii = (struct ng_mesg *)msg->data;
if ((msg->header.arglen < sizeof(*ascii) + 1)
|| (ascii->header.arglen < 1)
|| (msg->header.arglen
< sizeof(*ascii) + ascii->header.arglen)) {
TRAP_ERROR();
error = EINVAL;
break;
}
ascii->data[ascii->header.arglen - 1] = '\0';
/* Get a response message with lots of room */
NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
binary = (struct ng_mesg *)resp->data;
/* Copy ASCII message header to response message payload */
bcopy(ascii, binary, sizeof(*ascii));
/* Find command by matching ASCII command string */
for (c = here->nd_type->cmdlist;
c != NULL && c->name != NULL; c++) {
if (strcmp(ascii->header.cmdstr, c->name) == 0)
break;
}
if (c == NULL || c->name == NULL) {
for (c = ng_generic_cmds; c->name != NULL; c++) {
if (strcmp(ascii->header.cmdstr, c->name) == 0)
break;
}
if (c->name == NULL) {
NG_FREE_MSG(resp);
error = ENOSYS;
break;
}
}
/* Convert command name to binary */
binary->header.cmd = c->cmd;
binary->header.typecookie = c->cookie;
/* Convert command arguments to binary */
argstype = (binary->header.flags & NGF_RESP) ?
c->respType : c->mesgType;
if (argstype == NULL) {
bufSize = 0;
} else {
if ((error = ng_parse(argstype, ascii->data,
&off, (u_char *)binary->data, &bufSize)) != 0) {
NG_FREE_MSG(resp);
break;
}
}
/* Return the result */
binary->header.arglen = bufSize;
resp->header.arglen = sizeof(*binary) + bufSize;
break;
}
case NGM_TEXT_CONFIG:
case NGM_TEXT_STATUS:
/*
* This one is tricky as it passes the command down to the
* actual node, even though it is a generic type command.
* This means we must assume that the item/msg is already freed
* when control passes back to us.
*/
if (here->nd_type->rcvmsg != NULL) {
NGI_MSG(item) = msg; /* put it back as we found it */
return((*here->nd_type->rcvmsg)(here, item, lasthook));
}
/* Fall through if rcvmsg not supported */
default:
TRAP_ERROR();
error = EINVAL;
}
/*
* Sometimes a generic message may be statically allocated
* to avoid problems with allocating when in tight memeory situations.
* Don't free it if it is so.
* I break them appart here, because erros may cause a free if the item
* in which case we'd be doing it twice.
* they are kept together above, to simplify freeing.
*/
out:
NG_RESPOND_MSG(error, here, item, resp);
if (msg)
NG_FREE_MSG(msg);
return (error);
}
/************************************************************************
Queue element get/free routines
************************************************************************/
uma_zone_t ng_qzone;
static int maxalloc = 512; /* limit the damage of a leak */
TUNABLE_INT("net.graph.maxalloc", &maxalloc);
SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
0, "Maximum number of queue items to allocate");
#ifdef NETGRAPH_DEBUG
static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
static int allocated; /* number of items malloc'd */
#endif
/*
* Get a queue entry.
* This is usually called when a packet first enters netgraph.
* By definition, this is usually from an interrupt, or from a user.
* Users are not so important, but try be quick for the times that it's
* an interrupt.
*/
static __inline item_p
ng_getqblk(int flags)
{
item_p item = NULL;
int wait;
wait = (flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT;
item = uma_zalloc(ng_qzone, wait | M_ZERO);
#ifdef NETGRAPH_DEBUG
if (item) {
mtx_lock(&ngq_mtx);
TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
allocated++;
mtx_unlock(&ngq_mtx);
}
#endif
return (item);
}
/*
* Release a queue entry
*/
void
ng_free_item(item_p item)
{
KASSERT(item->apply == NULL, ("%s: leaking apply callback", __func__));
/*
* The item may hold resources on it's own. We need to free
* these before we can free the item. What they are depends upon
* what kind of item it is. it is important that nodes zero
* out pointers to resources that they remove from the item
* or we release them again here.
*/
switch (item->el_flags & NGQF_TYPE) {
case NGQF_DATA:
/* If we have an mbuf still attached.. */
NG_FREE_M(_NGI_M(item));
break;
case NGQF_MESG:
_NGI_RETADDR(item) = 0;
NG_FREE_MSG(_NGI_MSG(item));
break;
case NGQF_FN:
/* nothing to free really, */
_NGI_FN(item) = NULL;
_NGI_ARG1(item) = NULL;
_NGI_ARG2(item) = 0;
case NGQF_UNDEF:
break;
}
/* If we still have a node or hook referenced... */
_NGI_CLR_NODE(item);
_NGI_CLR_HOOK(item);
#ifdef NETGRAPH_DEBUG
mtx_lock(&ngq_mtx);
TAILQ_REMOVE(&ng_itemlist, item, all);
allocated--;
mtx_unlock(&ngq_mtx);
#endif
uma_zfree(ng_qzone, item);
}
/************************************************************************
Module routines
************************************************************************/
/*
* Handle the loading/unloading of a netgraph node type module
*/
int
ng_mod_event(module_t mod, int event, void *data)
{
struct ng_type *const type = data;
int s, error = 0;
switch (event) {
case MOD_LOAD:
/* Register new netgraph node type */
s = splnet();
if ((error = ng_newtype(type)) != 0) {
splx(s);
break;
}
/* Call type specific code */
if (type->mod_event != NULL)
if ((error = (*type->mod_event)(mod, event, data))) {
mtx_lock(&ng_typelist_mtx);
type->refs--; /* undo it */
LIST_REMOVE(type, types);
mtx_unlock(&ng_typelist_mtx);
}
splx(s);
break;
case MOD_UNLOAD:
s = splnet();
if (type->refs > 1) { /* make sure no nodes exist! */
error = EBUSY;
} else {
if (type->refs == 0) {
/* failed load, nothing to undo */
splx(s);
break;
}
if (type->mod_event != NULL) { /* check with type */
error = (*type->mod_event)(mod, event, data);
if (error != 0) { /* type refuses.. */
splx(s);
break;
}
}
mtx_lock(&ng_typelist_mtx);
LIST_REMOVE(type, types);
mtx_unlock(&ng_typelist_mtx);
}
splx(s);
break;
default:
if (type->mod_event != NULL)
error = (*type->mod_event)(mod, event, data);
else
error = EOPNOTSUPP; /* XXX ? */
break;
}
return (error);
}
/*
* Handle loading and unloading for this code.
* The only thing we need to link into is the NETISR strucure.
*/
static int
ngb_mod_event(module_t mod, int event, void *data)
{
int error = 0;
switch (event) {
case MOD_LOAD:
/* Initialize everything. */
mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_SPIN);
mtx_init(&ng_typelist_mtx, "netgraph types mutex", NULL,
MTX_DEF);
mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL,
MTX_DEF);
mtx_init(&ng_idhash_mtx, "netgraph idhash mutex", NULL,
MTX_DEF);
mtx_init(&ng_topo_mtx, "netgraph topology mutex", NULL,
MTX_DEF);
#ifdef NETGRAPH_DEBUG
mtx_init(&ngq_mtx, "netgraph item list mutex", NULL,
MTX_DEF);
#endif
ng_qzone = uma_zcreate("NetGraph items", sizeof(struct ng_item),
NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
uma_zone_set_max(ng_qzone, maxalloc);
netisr_register(NETISR_NETGRAPH, (netisr_t *)ngintr, NULL,
NETISR_MPSAFE);
break;
case MOD_UNLOAD:
/* You cant unload it because an interface may be using it. */
error = EBUSY;
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static moduledata_t netgraph_mod = {
"netgraph",
ngb_mod_event,
(NULL)
};
DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_MIDDLE);
SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
#ifdef NETGRAPH_DEBUG
void
dumphook (hook_p hook, char *file, int line)
{
printf("hook: name %s, %d refs, Last touched:\n",
_NG_HOOK_NAME(hook), hook->hk_refs);
printf(" Last active @ %s, line %d\n",
hook->lastfile, hook->lastline);
if (line) {
printf(" problem discovered at file %s, line %d\n", file, line);
}
}
void
dumpnode(node_p node, char *file, int line)
{
printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
_NG_NODE_ID(node), node->nd_type->name,
node->nd_numhooks, node->nd_flags,
node->nd_refs, node->nd_name);
printf(" Last active @ %s, line %d\n",
node->lastfile, node->lastline);
if (line) {
printf(" problem discovered at file %s, line %d\n", file, line);
}
}
void
dumpitem(item_p item, char *file, int line)
{
printf(" ACTIVE item, last used at %s, line %d",
item->lastfile, item->lastline);
switch(item->el_flags & NGQF_TYPE) {
case NGQF_DATA:
printf(" - [data]\n");
break;
case NGQF_MESG:
printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
break;
case NGQF_FN:
printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
item->body.fn.fn_fn,
_NGI_NODE(item),
_NGI_HOOK(item),
item->body.fn.fn_arg1,
item->body.fn.fn_arg2,
item->body.fn.fn_arg2);
break;
case NGQF_UNDEF:
printf(" - UNDEFINED!\n");
}
if (line) {
printf(" problem discovered at file %s, line %d\n", file, line);
if (_NGI_NODE(item)) {
printf("node %p ([%x])\n",
_NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
}
}
}
static void
ng_dumpitems(void)
{
item_p item;
int i = 1;
TAILQ_FOREACH(item, &ng_itemlist, all) {
printf("[%d] ", i++);
dumpitem(item, NULL, 0);
}
}
static void
ng_dumpnodes(void)
{
node_p node;
int i = 1;
mtx_lock(&ng_nodelist_mtx);
SLIST_FOREACH(node, &ng_allnodes, nd_all) {
printf("[%d] ", i++);
dumpnode(node, NULL, 0);
}
mtx_unlock(&ng_nodelist_mtx);
}
static void
ng_dumphooks(void)
{
hook_p hook;
int i = 1;
mtx_lock(&ng_nodelist_mtx);
SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
printf("[%d] ", i++);
dumphook(hook, NULL, 0);
}
mtx_unlock(&ng_nodelist_mtx);
}
static int
sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
{
int error;
int val;
int i;
val = allocated;
i = 1;
error = sysctl_handle_int(oidp, &val, sizeof(int), req);
if (error != 0 || req->newptr == NULL)
return (error);
if (val == 42) {
ng_dumpitems();
ng_dumpnodes();
ng_dumphooks();
}
return (0);
}
SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
0, sizeof(int), sysctl_debug_ng_dump_items, "I", "Number of allocated items");
#endif /* NETGRAPH_DEBUG */
/***********************************************************************
* Worklist routines
**********************************************************************/
/* NETISR thread enters here */
/*
* Pick a node off the list of nodes with work,
* try get an item to process off it.
* If there are no more, remove the node from the list.
*/
static void
ngintr(void)
{
item_p item;
node_p node = NULL;
for (;;) {
mtx_lock_spin(&ng_worklist_mtx);
node = TAILQ_FIRST(&ng_worklist);
if (!node) {
mtx_unlock_spin(&ng_worklist_mtx);
break;
}
node->nd_flags &= ~NGF_WORKQ;
TAILQ_REMOVE(&ng_worklist, node, nd_work);
mtx_unlock_spin(&ng_worklist_mtx);
/*
* We have the node. We also take over the reference
* that the list had on it.
* Now process as much as you can, until it won't
* let you have another item off the queue.
* All this time, keep the reference
* that lets us be sure that the node still exists.
* Let the reference go at the last minute.
* ng_dequeue will put us back on the worklist
* if there is more too do. This may be of use if there
* are Multiple Processors and multiple Net threads in the
* future.
*/
for (;;) {
int rw;
mtx_lock_spin(&node->nd_input_queue.q_mtx);
item = ng_dequeue(&node->nd_input_queue, &rw);
if (item == NULL) {
mtx_unlock_spin(&node->nd_input_queue.q_mtx);
break; /* go look for another node */
} else {
mtx_unlock_spin(&node->nd_input_queue.q_mtx);
NGI_GET_NODE(item, node); /* zaps stored node */
ng_apply_item(node, item, rw);
NG_NODE_UNREF(node);
}
}
NG_NODE_UNREF(node);
}
}
static void
ng_worklist_remove(node_p node)
{
mtx_lock_spin(&ng_worklist_mtx);
if (node->nd_flags & NGF_WORKQ) {
node->nd_flags &= ~NGF_WORKQ;
TAILQ_REMOVE(&ng_worklist, node, nd_work);
mtx_unlock_spin(&ng_worklist_mtx);
NG_NODE_UNREF(node);
} else {
mtx_unlock_spin(&ng_worklist_mtx);
}
}
/*
* XXX
* It's posible that a debugging NG_NODE_REF may need
* to be outside the mutex zone
*/
static void
ng_setisr(node_p node)
{
mtx_assert(&node->nd_input_queue.q_mtx, MA_OWNED);
if ((node->nd_flags & NGF_WORKQ) == 0) {
/*
* If we are not already on the work queue,
* then put us on.
*/
node->nd_flags |= NGF_WORKQ;
mtx_lock_spin(&ng_worklist_mtx);
TAILQ_INSERT_TAIL(&ng_worklist, node, nd_work);
mtx_unlock_spin(&ng_worklist_mtx);
NG_NODE_REF(node); /* XXX fafe in mutex? */
}
schednetisr(NETISR_NETGRAPH);
}
/***********************************************************************
* Externally useable functions to set up a queue item ready for sending
***********************************************************************/
#ifdef NETGRAPH_DEBUG
#define ITEM_DEBUG_CHECKS \
do { \
if (NGI_NODE(item) ) { \
printf("item already has node"); \
kdb_enter("has node"); \
NGI_CLR_NODE(item); \
} \
if (NGI_HOOK(item) ) { \
printf("item already has hook"); \
kdb_enter("has hook"); \
NGI_CLR_HOOK(item); \
} \
} while (0)
#else
#define ITEM_DEBUG_CHECKS
#endif
/*
* Put mbuf into the item.
* Hook and node references will be removed when the item is dequeued.
* (or equivalent)
* (XXX) Unsafe because no reference held by peer on remote node.
* remote node might go away in this timescale.
* We know the hooks can't go away because that would require getting
* a writer item on both nodes and we must have at least a reader
* here to be able to do this.
* Note that the hook loaded is the REMOTE hook.
*
* This is possibly in the critical path for new data.
*/
item_p
ng_package_data(struct mbuf *m, int flags)
{
item_p item;
if ((item = ng_getqblk(flags)) == NULL) {
NG_FREE_M(m);
return (NULL);
}
ITEM_DEBUG_CHECKS;
item->el_flags = NGQF_DATA | NGQF_READER;
item->el_next = NULL;
NGI_M(item) = m;
return (item);
}
/*
* Allocate a queue item and put items into it..
* Evaluate the address as this will be needed to queue it and
* to work out what some of the fields should be.
* Hook and node references will be removed when the item is dequeued.
* (or equivalent)
*/
item_p
ng_package_msg(struct ng_mesg *msg, int flags)
{
item_p item;
if ((item = ng_getqblk(flags)) == NULL) {
NG_FREE_MSG(msg);
return (NULL);
}
ITEM_DEBUG_CHECKS;
/* Messages items count as writers unless explicitly exempted. */
if (msg->header.cmd & NGM_READONLY)
item->el_flags = NGQF_MESG | NGQF_READER;
else
item->el_flags = NGQF_MESG | NGQF_WRITER;
item->el_next = NULL;
/*
* Set the current lasthook into the queue item
*/
NGI_MSG(item) = msg;
NGI_RETADDR(item) = 0;
return (item);
}
#define SET_RETADDR(item, here, retaddr) \
do { /* Data or fn items don't have retaddrs */ \
if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) { \
if (retaddr) { \
NGI_RETADDR(item) = retaddr; \
} else { \
/* \
* The old return address should be ok. \
* If there isn't one, use the address \
* here. \
*/ \
if (NGI_RETADDR(item) == 0) { \
NGI_RETADDR(item) \
= ng_node2ID(here); \
} \
} \
} \
} while (0)
int
ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
{
hook_p peer;
node_p peernode;
ITEM_DEBUG_CHECKS;
/*
* Quick sanity check..
* Since a hook holds a reference on it's node, once we know
* that the peer is still connected (even if invalid,) we know
* that the peer node is present, though maybe invalid.
*/
if ((hook == NULL)
|| NG_HOOK_NOT_VALID(hook)
|| (NG_HOOK_PEER(hook) == NULL)
|| NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))
|| NG_NODE_NOT_VALID(NG_PEER_NODE(hook))) {
NG_FREE_ITEM(item);
TRAP_ERROR();
return (ENETDOWN);
}
/*
* Transfer our interest to the other (peer) end.
*/
peer = NG_HOOK_PEER(hook);
NG_HOOK_REF(peer);
NGI_SET_HOOK(item, peer);
peernode = NG_PEER_NODE(hook);
NG_NODE_REF(peernode);
NGI_SET_NODE(item, peernode);
SET_RETADDR(item, here, retaddr);
return (0);
}
int
ng_address_path(node_p here, item_p item, char *address, ng_ID_t retaddr)
{
node_p dest = NULL;
hook_p hook = NULL;
int error;
ITEM_DEBUG_CHECKS;
/*
* Note that ng_path2noderef increments the reference count
* on the node for us if it finds one. So we don't have to.
*/
error = ng_path2noderef(here, address, &dest, &hook);
if (error) {
NG_FREE_ITEM(item);
return (error);
}
NGI_SET_NODE(item, dest);
if ( hook) {
NG_HOOK_REF(hook); /* don't let it go while on the queue */
NGI_SET_HOOK(item, hook);
}
SET_RETADDR(item, here, retaddr);
return (0);
}
int
ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
{
node_p dest;
ITEM_DEBUG_CHECKS;
/*
* Find the target node.
*/
dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
if (dest == NULL) {
NG_FREE_ITEM(item);
TRAP_ERROR();
return(EINVAL);
}
/* Fill out the contents */
NGI_SET_NODE(item, dest);
NGI_CLR_HOOK(item);
SET_RETADDR(item, here, retaddr);
return (0);
}
/*
* special case to send a message to self (e.g. destroy node)
* Possibly indicate an arrival hook too.
* Useful for removing that hook :-)
*/
item_p
ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
{
item_p item;
/*
* Find the target node.
* If there is a HOOK argument, then use that in preference
* to the address.
*/
if ((item = ng_getqblk(NG_NOFLAGS)) == NULL) {
NG_FREE_MSG(msg);
return (NULL);
}
/* Fill out the contents */
item->el_flags = NGQF_MESG | NGQF_WRITER;
item->el_next = NULL;
NG_NODE_REF(here);
NGI_SET_NODE(item, here);
if (hook) {
NG_HOOK_REF(hook);
NGI_SET_HOOK(item, hook);
}
NGI_MSG(item) = msg;
NGI_RETADDR(item) = ng_node2ID(here);
return (item);
}
int
ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
int flags)
{
item_p item;
if ((item = ng_getqblk(flags)) == NULL) {
return (ENOMEM);
}
item->el_flags = NGQF_FN | NGQF_WRITER;
NG_NODE_REF(node); /* and one for the item */
NGI_SET_NODE(item, node);
if (hook) {
NG_HOOK_REF(hook);
NGI_SET_HOOK(item, hook);
}
NGI_FN(item) = fn;
NGI_ARG1(item) = arg1;
NGI_ARG2(item) = arg2;
return(ng_snd_item(item, flags));
}
/*
* Official timeout routines for Netgraph nodes.
*/
static void
ng_callout_trampoline(void *arg)
{
item_p item = arg;
ng_snd_item(item, 0);
}
int
ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
ng_item_fn *fn, void * arg1, int arg2)
{
item_p item, oitem;
if ((item = ng_getqblk(NG_NOFLAGS)) == NULL)
return (ENOMEM);
item->el_flags = NGQF_FN | NGQF_WRITER;
NG_NODE_REF(node); /* and one for the item */
NGI_SET_NODE(item, node);
if (hook) {
NG_HOOK_REF(hook);
NGI_SET_HOOK(item, hook);
}
NGI_FN(item) = fn;
NGI_ARG1(item) = arg1;
NGI_ARG2(item) = arg2;
oitem = c->c_arg;
if (callout_reset(c, ticks, &ng_callout_trampoline, item) == 1 &&
oitem != NULL)
NG_FREE_ITEM(oitem);
return (0);
}
/* A special modified version of untimeout() */
int
ng_uncallout(struct callout *c, node_p node)
{
item_p item;
int rval;
KASSERT(c != NULL, ("ng_uncallout: NULL callout"));
KASSERT(node != NULL, ("ng_uncallout: NULL node"));
rval = callout_stop(c);
item = c->c_arg;
/* Do an extra check */
if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
(NGI_NODE(item) == node)) {
/*
* We successfully removed it from the queue before it ran
* So now we need to unreference everything that was
* given extra references. (NG_FREE_ITEM does this).
*/
NG_FREE_ITEM(item);
}
c->c_arg = NULL;
return (rval);
}
/*
* Set the address, if none given, give the node here.
*/
void
ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
{
if (retaddr) {
NGI_RETADDR(item) = retaddr;
} else {
/*
* The old return address should be ok.
* If there isn't one, use the address here.
*/
NGI_RETADDR(item) = ng_node2ID(here);
}
}
#define TESTING
#ifdef TESTING
/* just test all the macros */
void
ng_macro_test(item_p item);
void
ng_macro_test(item_p item)
{
node_p node = NULL;
hook_p hook = NULL;
struct mbuf *m;
struct ng_mesg *msg;
ng_ID_t retaddr;
int error;
NGI_GET_M(item, m);
NGI_GET_MSG(item, msg);
retaddr = NGI_RETADDR(item);
NG_SEND_DATA(error, hook, m, NULL);
NG_SEND_DATA_ONLY(error, hook, m);
NG_FWD_NEW_DATA(error, item, hook, m);
NG_FWD_ITEM_HOOK(error, item, hook);
NG_SEND_MSG_HOOK(error, node, msg, hook, retaddr);
NG_SEND_MSG_ID(error, node, msg, retaddr, retaddr);
NG_SEND_MSG_PATH(error, node, msg, ".:", retaddr);
NG_FWD_MSG_HOOK(error, node, item, hook, retaddr);
}
#endif /* TESTING */
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