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dc90cad9d2
freebsd-skq/sys/netgraph/ng_base.c
Julian Elischer dc90cad9d2 Start making the contents of the generic framework opaque to the nodes. 
This step: IDs are no-longer the address of the node.
Reviewd by: Archie@freebsd.org
1999-11-01 00:31:14 +00:00

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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@whistle.com>
* Archie Cobbs <archie@whistle.com>
*
* $FreeBSD$
* $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/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <sys/linker.h>
#include <sys/queue.h>
#include <sys/mbuf.h>
#include <sys/socketvar.h>
#include <net/netisr.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
/* List of all nodes */
static LIST_HEAD(, ng_node) nodelist;
/* List of installed types */
static LIST_HEAD(, ng_type) typelist;
/* Hash releted definitions */
#define ID_HASH_SIZE 32 /* most systems wont need even this many */
static LIST_HEAD(, ng_node) ID_hash[ID_HASH_SIZE];
/* Don't nead to initialise them because it's a LIST */
/* Internal functions */
static int ng_add_hook(node_p node, const char *name, hook_p * hookp);
static int ng_connect(hook_p hook1, hook_p hook2);
static void ng_disconnect_hook(hook_p hook);
static int ng_generic_msg(node_p here, struct ng_mesg *msg,
const char *retaddr, struct ng_mesg ** resp);
static ng_ID_t ng_decodeidname(const char *name);
static int ngb_mod_event(module_t mod, int event, void *data);
static void ngintr(void);
/* Our own netgraph malloc type */
MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
/* Set this to Debugger("X") to catch all errors as they occur */
#ifndef TRAP_ERROR
#define TRAP_ERROR
#endif
static ng_ID_t nextID = 1;
/************************************************************************
Node routines
************************************************************************/
/*
* Instantiate a node of the requested type
*/
int
ng_make_node(const char *typename, node_p *nodepp)
{
struct ng_type *type;
/* Check that the type makes sense */
if (typename == NULL) {
TRAP_ERROR;
return (EINVAL);
}
/* Locate the node type */
if ((type = ng_findtype(typename)) == NULL) {
char *path, filename[NG_TYPELEN + 4];
linker_file_t lf;
int error;
/* Not found, try to load it as a loadable module */
snprintf(filename, sizeof(filename), "ng_%s.ko", typename);
if ((path = linker_search_path(filename)) == NULL)
return (ENXIO);
error = linker_load_file(path, &lf);
FREE(path, M_LINKER);
if (error != 0)
return (error);
lf->userrefs++; /* pretend loaded by the syscall */
/* Try again, as now the type should have linked itself in */
if ((type = ng_findtype(typename)) == NULL)
return (ENXIO);
}
/* Call the constructor */
if (type->constructor != NULL)
return ((*type->constructor)(nodepp));
else
return (ng_make_node_common(type, nodepp));
}
/*
* Generic node creation. Called by node constructors.
* 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 */
MALLOC(node, node_p, sizeof(*node), M_NETGRAPH, M_WAITOK);
if (node == NULL) {
TRAP_ERROR;
return (ENOMEM);
}
bzero(node, sizeof(*node));
node->type = type;
node->refs++; /* note reference */
type->refs++;
/* Link us into the node linked list */
LIST_INSERT_HEAD(&nodelist, node, nodes);
/* Initialize hook list for new node */
LIST_INIT(&node->hooks);
/* get an ID and put us in the hash chain */
node->ID = nextID++; /* 137 per second for 1 year before wrap */
LIST_INSERT_HEAD(&ID_hash[node->ID % ID_HASH_SIZE], node, idnodes);
/* 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.
*
* Persistent nodes must have a type-specific method which
* resets the NG_INVALID flag.
*/
void
ng_rmnode(node_p node)
{
/* Check if it's already shutting down */
if ((node->flags & NG_INVALID) != 0)
return;
/* Add an extra reference so it doesn't go away during this */
node->refs++;
/* Mark it invalid so any newcomers know not to try use it */
node->flags |= NG_INVALID;
/* Ask the type if it has anything to do in this case */
if (node->type && node->type->shutdown)
(*node->type->shutdown)(node);
else { /* do the default thing */
ng_unname(node);
ng_cutlinks(node);
ng_unref(node);
}
/* Remove extra reference, possibly the last */
ng_unref(node);
}
/*
* Called by the destructor to remove any STANDARD external references
*/
void
ng_cutlinks(node_p node)
{
hook_p hook;
/* Make sure that this is set to stop infinite loops */
node->flags |= NG_INVALID;
/* If we have sleepers, wake them up; they'll see NG_INVALID */
if (node->sleepers)
wakeup(node);
/* Notify all remaining connected nodes to disconnect */
while ((hook = LIST_FIRST(&node->hooks)) != NULL)
ng_destroy_hook(hook);
}
/*
* Remove a reference to the node, possibly the last
*/
void
ng_unref(node_p node)
{
if (--node->refs <= 0) {
node->type->refs--;
LIST_REMOVE(node, nodes);
LIST_REMOVE(node, idnodes);
FREE(node, M_NETGRAPH);
}
}
/*
* Wait for a node to come ready. Returns a node with a reference count;
* don't forget to drop it when we are done with it using ng_release_node().
*/
int
ng_wait_node(node_p node, char *msg)
{
int s, error = 0;
if (msg == NULL)
msg = "netgraph";
s = splnet();
node->sleepers++;
node->refs++; /* the sleeping process counts as a reference */
while ((node->flags & (NG_BUSY | NG_INVALID)) == NG_BUSY)
error = tsleep(node, (PZERO + 1) | PCATCH, msg, 0);
node->sleepers--;
if (node->flags & NG_INVALID) {
TRAP_ERROR;
error = ENXIO;
} else {
#ifdef DIAGNOSTIC
if (node->refs == 1) {
panic(__FUNCTION__);
error = ENXIO;
}
#endif
node->flags |= NG_BUSY;
}
splx(s);
/* Release the reference we had on it */
if (error != 0)
ng_unref(node);
return error;
}
/*
* Release a node acquired via ng_wait_node()
*/
void
ng_release_node(node_p node)
{
/* Declare that we don't want it */
node->flags &= ~NG_BUSY;
/* If we have sleepers, then wake them up */
if (node->sleepers)
wakeup(node);
/* We also have a reference.. drop it too */
ng_unref(node);
}
/************************************************************************
Node ID handling
************************************************************************/
static node_p
ng_ID2node(ng_ID_t ID)
{
node_p np;
LIST_FOREACH(np, &ID_hash[ID % ID_HASH_SIZE], idnodes) {
if (np->ID == ID)
break;
}
return(np);
}
ng_ID_t
ng_node2ID(node_p node)
{
return (node->ID);
}
/************************************************************************
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;
/* Check the name is valid */
for (i = 0; i < NG_NODELEN + 1; 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 node isn't already named */
if (node->name != NULL) {
TRAP_ERROR;
return (EISCONN);
}
/* Check the name isn't already being used */
if (ng_findname(node, name) != NULL) {
TRAP_ERROR;
return (EADDRINUSE);
}
/* Allocate space and copy it */
MALLOC(node->name, char *, strlen(name) + 1, M_NETGRAPH, M_WAITOK);
if (node->name == NULL) {
TRAP_ERROR;
return (ENOMEM);
}
strcpy(node->name, name);
/* The name counts as a reference */
node->refs++;
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.
*/
node_p
ng_findname(node_p this, const char *name)
{
node_p node;
ng_ID_t temp;
/* "." means "this node" */
if (strcmp(name, ".") == 0)
return(this);
/* Check for name-by-ID */
if ((temp = ng_decodeidname(name)) != 0) {
return (ng_ID2node(temp));
}
/* Find node by name */
LIST_FOREACH(node, &nodelist, nodes) {
if (node->name != NULL && strcmp(node->name, name) == 0)
break;
}
return (node);
}
/*
* Decode a 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)
{
ng_ID_t val;
int k, len;
/* Basic checks */
for (len = 0; name[len] != '\0'; len++) {
const char ch = name[len];
if (len == 0) {
if (ch != '[')
return (NULL);
} else if (name[len + 1] == '\0') {
if (ch != ']')
return (NULL);
} else if (!((ch >= '0' && ch <= '9')
|| (ch >= 'a' && ch <= 'f')
|| (ch >= 'A' && ch <= 'F')))
return (NULL);
}
if (len < 3 || len > (sizeof(val) * 2) + 2 || name[1] == '0')
return (NULL);
/* Convert number to binary */
for (val = 0, k = 1; k < len - 1; k++) {
const char ch = name[k];
if (ch <= '9')
val = (val << 4) | ((ch - '0') & 0xf);
else
val = (val << 4) | (((ch & 0xdf) - 'A' + 10) & 0xf);
}
return (val);
}
/*
* Remove a name from a node. This should only be called
* when shutting down and removing the node.
*/
void
ng_unname(node_p node)
{
if (node->name) {
FREE(node->name, M_NETGRAPH);
node->name = NULL;
ng_unref(node);
}
}
/************************************************************************
Hook routines
Names are not optional. Hooks are always connected, except for a
brief moment within these routines.
************************************************************************/
/*
* Remove a hook reference
*/
static void
ng_unref_hook(hook_p hook)
{
if (--hook->refs == 0)
FREE(hook, M_NETGRAPH);
}
/*
* Add an unconnected hook to a node. Only used internally.
*/
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);
}
LIST_FOREACH(hook, &node->hooks, hooks) {
if (strcmp(hook->name, name) == 0) {
TRAP_ERROR;
return (EEXIST);
}
}
/* Allocate the hook and link it up */
MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH, M_WAITOK);
if (hook == NULL) {
TRAP_ERROR;
return (ENOMEM);
}
bzero(hook, sizeof(*hook));
hook->refs = 1;
hook->flags = HK_INVALID;
hook->node = node;
node->refs++; /* each hook counts as a reference */
/* Check if the node type code has something to say about it */
if (node->type->newhook != NULL)
if ((error = (*node->type->newhook)(node, hook, name)) != 0)
goto fail;
/*
* 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->hooks, hook, hooks);
node->numhooks++;
/* Set hook name */
MALLOC(hook->name, char *, strlen(name) + 1, M_NETGRAPH, M_WAITOK);
if (hook->name == NULL) {
error = ENOMEM;
LIST_REMOVE(hook, hooks);
node->numhooks--;
fail:
hook->node = NULL;
ng_unref(node);
ng_unref_hook(hook); /* this frees the hook */
return (error);
}
strcpy(hook->name, name);
if (hookp)
*hookp = hook;
return (error);
}
/*
* Connect a pair of hooks. Only used internally.
*/
static int
ng_connect(hook_p hook1, hook_p hook2)
{
int error;
hook1->peer = hook2;
hook2->peer = hook1;
/* Give each node the opportunity to veto the impending connection */
if (hook1->node->type->connect) {
if ((error = (*hook1->node->type->connect) (hook1))) {
ng_destroy_hook(hook1); /* also zaps hook2 */
return (error);
}
}
if (hook2->node->type->connect) {
if ((error = (*hook2->node->type->connect) (hook2))) {
ng_destroy_hook(hook2); /* also zaps hook1 */
return (error);
}
}
hook1->flags &= ~HK_INVALID;
hook2->flags &= ~HK_INVALID;
return (0);
}
/*
* 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.
*/
void
ng_destroy_hook(hook_p hook)
{
hook_p peer = hook->peer;
hook->flags |= HK_INVALID; /* as soon as possible */
if (peer) {
peer->flags |= HK_INVALID; /* as soon as possible */
hook->peer = NULL;
peer->peer = NULL;
ng_disconnect_hook(peer);
}
ng_disconnect_hook(hook);
}
/*
* Notify the node of the hook's demise. This may result in more actions
* (e.g. shutdown) but we don't do that ourselves and don't know what
* happens there. If there is no appropriate handler, then just remove it
* (and decrement the reference count of it's node which in turn might
* make something happen).
*/
static void
ng_disconnect_hook(hook_p hook)
{
node_p node = hook->node;
/*
* Remove the hook from the node's list to avoid possible recursion
* in case the disconnection results in node shutdown.
*/
LIST_REMOVE(hook, hooks);
node->numhooks--;
if (node->type->disconnect) {
/*
* The type handler may elect to destroy the peer so don't
* trust its existance after this point.
*/
(*node->type->disconnect) (hook);
}
ng_unref(node); /* might be the last reference */
if (hook->name)
FREE(hook->name, M_NETGRAPH);
hook->node = NULL; /* may still be referenced elsewhere */
ng_unref_hook(hook);
}
/*
* 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->node != hook2->node)
return (EINVAL);
hook1->peer->peer = hook2->peer;
hook2->peer->peer = hook1->peer;
/* XXX If we ever cache methods on hooks update them as well */
hook1->peer = NULL;
hook2->peer = NULL;
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_VERSION || namelen == 0 || namelen > NG_TYPELEN) {
TRAP_ERROR;
return (EINVAL);
}
/* Check for name collision */
if (ng_findtype(tp->name) != NULL) {
TRAP_ERROR;
return (EEXIST);
}
/* Link in new type */
LIST_INSERT_HEAD(&typelist, tp, types);
tp->refs = 0;
return (0);
}
/*
* Look for a type of the name given
*/
struct ng_type *
ng_findtype(const char *typename)
{
struct ng_type *type;
LIST_FOREACH(type, &typelist, types) {
if (strcmp(type->name, typename) == 0)
break;
}
return (type);
}
/************************************************************************
Composite routines
************************************************************************/
/*
* Make a peer and connect. The order is arranged to minimise
* the work needed to back out in case of error.
*/
int
ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
{
node_p node2;
hook_p hook;
hook_p hook2;
int error;
if ((error = ng_add_hook(node, name, &hook)))
return (error);
if ((error = ng_make_node(type, &node2))) {
ng_destroy_hook(hook);
return (error);
}
if ((error = ng_add_hook(node2, name2, &hook2))) {
ng_rmnode(node2);
ng_destroy_hook(hook);
return (error);
}
/*
* Actually link the two hooks together.. on failure they are
* destroyed so we don't have to do that here.
*/
if ((error = ng_connect(hook, hook2)))
ng_rmnode(node2);
return (error);
}
/*
* Connect two nodes using the specified hooks
*/
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 ((error = ng_add_hook(node, name, &hook)))
return (error);
if ((error = ng_add_hook(node2, name2, &hook2))) {
ng_destroy_hook(hook);
return (error);
}
return (ng_connect(hook, hook2));
}
/*
* 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. Compute the "return address" if desired.
*/
int
ng_path2node(node_p here, const char *address, node_p *destp, char **rtnp)
{
const node_p start = here;
char fullpath[NG_PATHLEN + 1];
char *nodename, *path, pbuf[2];
node_p node;
char *cp;
/* Initialize */
if (rtnp)
*rtnp = NULL;
if (destp == NULL)
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 */
if (nodename) {
node = ng_findname(here, nodename);
if (node == NULL) {
TRAP_ERROR;
return (ENOENT);
}
} else
node = here;
/* Now follow the sequence of hooks */
for (cp = path; node != NULL && *cp != '\0'; ) {
hook_p hook;
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 */
LIST_FOREACH(hook, &node->hooks, hooks) {
if (hook->name && strcmp(hook->name, segment) == 0)
break;
}
/* Can't get there from here... */
if (hook == NULL
|| hook->peer == NULL
|| (hook->flags & HK_INVALID) != 0) {
TRAP_ERROR;
return (ENOENT);
}
/* Hop on over to the next node */
node = hook->peer->node;
}
/* If node somehow missing, fail here (probably this is not needed) */
if (node == NULL) {
TRAP_ERROR;
return (ENXIO);
}
/* Now compute return address, i.e., the path to the sender */
if (rtnp != NULL) {
MALLOC(*rtnp, char *, NG_NODELEN + 2, M_NETGRAPH, M_WAITOK);
if (*rtnp == NULL) {
TRAP_ERROR;
return (ENOMEM);
}
if (start->name != NULL)
sprintf(*rtnp, "%s:", start->name);
else
sprintf(*rtnp, "[%x]:", ng_node2ID(start));
}
/* Done */
*destp = node;
return (0);
}
/*
* 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)
*/
#define CALL_MSG_HANDLER(error, node, msg, retaddr, resp) \
do { \
if((msg)->header.typecookie == NGM_GENERIC_COOKIE) { \
(error) = ng_generic_msg((node), (msg), \
(retaddr), (resp)); \
} else { \
if ((node)->type->rcvmsg != NULL) { \
(error) = (*(node)->type->rcvmsg)((node), \
(msg), (retaddr), (resp)); \
} else { \
TRAP_ERROR; \
FREE((msg), M_NETGRAPH); \
(error) = EINVAL; \
} \
} \
} while (0)
/*
* Send a control message to a node
*/
int
ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
struct ng_mesg **rptr)
{
node_p dest = NULL;
char *retaddr = NULL;
int error;
/* Find the target node */
error = ng_path2node(here, address, &dest, &retaddr);
if (error) {
FREE(msg, M_NETGRAPH);
return error;
}
/* Make sure the resp field is null before we start */
if (rptr != NULL)
*rptr = NULL;
CALL_MSG_HANDLER(error, dest, msg, retaddr, rptr);
/* Make sure that if there is a response, it has the RESP bit set */
if ((error == 0) && rptr && *rptr)
(*rptr)->header.flags |= NGF_RESP;
/*
* If we had a return address it is up to us to free it. They should
* have taken a copy if they needed to make a delayed response.
*/
if (retaddr)
FREE(retaddr, M_NETGRAPH);
return (error);
}
/*
* Implement the 'generic' control messages
*/
static int
ng_generic_msg(node_p here, struct ng_mesg *msg, const char *retaddr,
struct ng_mesg **resp)
{
int error = 0;
if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
TRAP_ERROR;
FREE(msg, M_NETGRAPH);
return (EINVAL);
}
switch (msg->header.cmd) {
case NGM_SHUTDOWN:
ng_rmnode(here);
break;
case NGM_MKPEER:
{
struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
if (msg->header.arglen != sizeof(*mkp)) {
TRAP_ERROR;
return (EINVAL);
}
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;
return (EINVAL);
}
con->path[sizeof(con->path) - 1] = '\0';
con->ourhook[sizeof(con->ourhook) - 1] = '\0';
con->peerhook[sizeof(con->peerhook) - 1] = '\0';
error = ng_path2node(here, con->path, &node2, NULL);
if (error)
break;
error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
break;
}
case NGM_NAME:
{
struct ngm_name *const nam = (struct ngm_name *) msg->data;
if (msg->header.arglen != sizeof(*nam)) {
TRAP_ERROR;
return (EINVAL);
}
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;
return (EINVAL);
}
rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
LIST_FOREACH(hook, &here->hooks, hooks) {
if (hook->name && strcmp(hook->name, rmh->ourhook) == 0)
break;
}
if (hook)
ng_destroy_hook(hook);
break;
}
case NGM_NODEINFO:
{
struct nodeinfo *ni;
struct ng_mesg *rp;
/* Get response struct */
if (resp == NULL) {
error = EINVAL;
break;
}
NG_MKRESPONSE(rp, msg, sizeof(*ni), M_NOWAIT);
if (rp == NULL) {
error = ENOMEM;
break;
}
/* Fill in node info */
ni = (struct nodeinfo *) rp->data;
if (here->name != NULL)
strncpy(ni->name, here->name, NG_NODELEN);
strncpy(ni->type, here->type->name, NG_TYPELEN);
ni->id = ng_node2ID(here);
ni->hooks = here->numhooks;
*resp = rp;
break;
}
case NGM_LISTHOOKS:
{
const int nhooks = here->numhooks;
struct hooklist *hl;
struct nodeinfo *ni;
struct ng_mesg *rp;
hook_p hook;
/* Get response struct */
if (resp == NULL) {
error = EINVAL;
break;
}
NG_MKRESPONSE(rp, msg, sizeof(*hl)
+ (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
if (rp == NULL) {
error = ENOMEM;
break;
}
hl = (struct hooklist *) rp->data;
ni = &hl->nodeinfo;
/* Fill in node info */
if (here->name)
strncpy(ni->name, here->name, NG_NODELEN);
strncpy(ni->type, here->type->name, NG_TYPELEN);
ni->id = ng_node2ID(here);
/* Cycle through the linked list of hooks */
ni->hooks = 0;
LIST_FOREACH(hook, &here->hooks, hooks) {
struct linkinfo *const link = &hl->link[ni->hooks];
if (ni->hooks >= nhooks) {
log(LOG_ERR, "%s: number of %s changed\n",
__FUNCTION__, "hooks");
break;
}
if ((hook->flags & HK_INVALID) != 0)
continue;
strncpy(link->ourhook, hook->name, NG_HOOKLEN);
strncpy(link->peerhook, hook->peer->name, NG_HOOKLEN);
if (hook->peer->node->name != NULL)
strncpy(link->nodeinfo.name,
hook->peer->node->name, NG_NODELEN);
strncpy(link->nodeinfo.type,
hook->peer->node->type->name, NG_TYPELEN);
link->nodeinfo.id = ng_node2ID(hook->peer->node);
link->nodeinfo.hooks = hook->peer->node->numhooks;
ni->hooks++;
}
*resp = rp;
break;
}
case NGM_LISTNAMES:
case NGM_LISTNODES:
{
const int unnamed = (msg->header.cmd == NGM_LISTNODES);
struct namelist *nl;
struct ng_mesg *rp;
node_p node;
int num = 0;
if (resp == NULL) {
error = EINVAL;
break;
}
/* Count number of nodes */
LIST_FOREACH(node, &nodelist, nodes) {
if (unnamed || node->name != NULL)
num++;
}
/* Get response struct */
if (resp == NULL) {
error = EINVAL;
break;
}
NG_MKRESPONSE(rp, msg, sizeof(*nl)
+ (num * sizeof(struct nodeinfo)), M_NOWAIT);
if (rp == NULL) {
error = ENOMEM;
break;
}
nl = (struct namelist *) rp->data;
/* Cycle through the linked list of nodes */
nl->numnames = 0;
LIST_FOREACH(node, &nodelist, nodes) {
struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
if (nl->numnames >= num) {
log(LOG_ERR, "%s: number of %s changed\n",
__FUNCTION__, "nodes");
break;
}
if ((node->flags & NG_INVALID) != 0)
continue;
if (!unnamed && node->name == NULL)
continue;
if (node->name != NULL)
strncpy(np->name, node->name, NG_NODELEN);
strncpy(np->type, node->type->name, NG_TYPELEN);
np->id = ng_node2ID(node);
np->hooks = node->numhooks;
nl->numnames++;
}
*resp = rp;
break;
}
case NGM_LISTTYPES:
{
struct typelist *tl;
struct ng_mesg *rp;
struct ng_type *type;
int num = 0;
if (resp == NULL) {
error = EINVAL;
break;
}
/* Count number of types */
LIST_FOREACH(type, &typelist, types)
num++;
/* Get response struct */
if (resp == NULL) {
error = EINVAL;
break;
}
NG_MKRESPONSE(rp, msg, sizeof(*tl)
+ (num * sizeof(struct typeinfo)), M_NOWAIT);
if (rp == NULL) {
error = ENOMEM;
break;
}
tl = (struct typelist *) rp->data;
/* Cycle through the linked list of types */
tl->numtypes = 0;
LIST_FOREACH(type, &typelist, types) {
struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
if (tl->numtypes >= num) {
log(LOG_ERR, "%s: number of %s changed\n",
__FUNCTION__, "types");
break;
}
strncpy(tp->typename, type->name, NG_TYPELEN);
tp->numnodes = type->refs;
tl->numtypes++;
}
*resp = rp;
break;
}
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 msg is already freed
* when control passes back to us.
*/
if (resp == NULL) {
error = EINVAL;
break;
}
if (here->type->rcvmsg != NULL)
return((*here->type->rcvmsg)(here, msg, retaddr, resp));
/* Fall through if rcvmsg not supported */
default:
TRAP_ERROR;
error = EINVAL;
}
FREE(msg, M_NETGRAPH);
return (error);
}
/*
* Send a data packet to a node. If the recipient has no
* 'receive data' method, then silently discard the packet.
*/
int
ng_send_data(hook_p hook, struct mbuf *m, meta_p meta)
{
int (*rcvdata)(hook_p, struct mbuf *, meta_p);
int error;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic(__FUNCTION__);
#endif
if (hook && (hook->flags & HK_INVALID) == 0) {
rcvdata = hook->peer->node->type->rcvdata;
if (rcvdata != NULL)
error = (*rcvdata)(hook->peer, m, meta);
else {
error = 0;
NG_FREE_DATA(m, meta);
}
} else {
TRAP_ERROR;
error = ENOTCONN;
NG_FREE_DATA(m, meta);
}
return (error);
}
/*
* Send a queued data packet to a node. If the recipient has no
* 'receive queued data' method, then try the 'receive data' method above.
*/
int
ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta)
{
int (*rcvdataq)(hook_p, struct mbuf *, meta_p);
int error;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic(__FUNCTION__);
#endif
if (hook && (hook->flags & HK_INVALID) == 0) {
rcvdataq = hook->peer->node->type->rcvdataq;
if (rcvdataq != NULL)
error = (*rcvdataq)(hook->peer, m, meta);
else {
error = ng_send_data(hook, m, meta);
}
} else {
TRAP_ERROR;
error = ENOTCONN;
NG_FREE_DATA(m, meta);
}
return (error);
}
/************************************************************************
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)) != 0)
LIST_REMOVE(type, types);
splx(s);
break;
case MOD_UNLOAD:
s = splnet();
if (type->refs != 0) /* make sure no nodes exist! */
error = EBUSY;
else {
if (type->mod_event != NULL) { /* check with type */
error = (*type->mod_event)(mod, event, data);
if (error != 0) { /* type refuses.. */
splx(s);
break;
}
}
LIST_REMOVE(type, types);
}
splx(s);
break;
default:
if (type->mod_event != NULL)
error = (*type->mod_event)(mod, event, data);
else
error = 0; /* 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 s, error = 0;
switch (event) {
case MOD_LOAD:
/* Register line discipline */
s = splimp();
error = register_netisr(NETISR_NETGRAPH, ngintr);
splx(s);
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_DRIVERS, SI_ORDER_MIDDLE);
/************************************************************************
Queueing routines
************************************************************************/
/* The structure for queueing across ISR switches */
struct ng_queue_entry {
u_long flags;
struct ng_queue_entry *next;
union {
struct {
hook_p da_hook; /* target hook */
struct mbuf *da_m;
meta_p da_meta;
} data;
struct {
struct ng_mesg *msg_msg;
node_p msg_node;
void *msg_retaddr;
} msg;
} body;
};
#define NGQF_DATA 0x01 /* the queue element is data */
#define NGQF_MESG 0x02 /* the queue element is a message */
static struct ng_queue_entry *ngqbase; /* items to be unqueued */
static struct ng_queue_entry *ngqlast; /* last item queued */
static const int ngqroom = 64; /* max items to queue */
static int ngqsize; /* number of items in queue */
static struct ng_queue_entry *ngqfree; /* free ones */
static const int ngqfreemax = 16;/* cache at most this many */
static int ngqfreesize; /* number of cached entries */
/*
* Get a queue entry
*/
static struct ng_queue_entry *
ng_getqblk(void)
{
register struct ng_queue_entry *q;
int s;
/* Could be guarding against tty ints or whatever */
s = splhigh();
/* Try get a cached queue block, or else allocate a new one */
if ((q = ngqfree) == NULL) {
splx(s);
if (ngqsize < ngqroom) { /* don't worry about races */
MALLOC(q, struct ng_queue_entry *,
sizeof(*q), M_NETGRAPH, M_NOWAIT);
}
} else {
ngqfree = q->next;
ngqfreesize--;
splx(s);
}
return (q);
}
/*
* Release a queue entry
*/
#define RETURN_QBLK(q) \
do { \
int s; \
if (ngqfreesize < ngqfreemax) { /* don't worry about races */ \
s = splhigh(); \
(q)->next = ngqfree; \
ngqfree = (q); \
ngqfreesize++; \
splx(s); \
} else { \
FREE((q), M_NETGRAPH); \
} \
} while (0)
/*
* Running at a raised (but we don't know which) processor priority level,
* put the data onto a queue to be picked up by another PPL (probably splnet)
*/
int
ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta)
{
struct ng_queue_entry *q;
int s;
if (hook == NULL) {
NG_FREE_DATA(m, meta);
return (0);
}
if ((q = ng_getqblk()) == NULL) {
NG_FREE_DATA(m, meta);
return (ENOBUFS);
}
/* Fill out the contents */
q->flags = NGQF_DATA;
q->next = NULL;
q->body.data.da_hook = hook;
q->body.data.da_m = m;
q->body.data.da_meta = meta;
hook->refs++; /* don't let it go away while on the queue */
/* Put it on the queue */
s = splhigh();
if (ngqbase) {
ngqlast->next = q;
} else {
ngqbase = q;
}
ngqlast = q;
ngqsize++;
splx(s);
/* Schedule software interrupt to handle it later */
schednetisr(NETISR_NETGRAPH);
return (0);
}
/*
* Running at a raised (but we don't know which) processor priority level,
* put the msg onto a queue to be picked up by another PPL (probably splnet)
*/
int
ng_queue_msg(node_p here, struct ng_mesg * msg, int len, const char *address)
{
register struct ng_queue_entry *q;
int s;
node_p dest = NULL;
char *retaddr = NULL;
int error;
/* Find the target node. */
error = ng_path2node(here, address, &dest, &retaddr);
if (error) {
FREE(msg, M_NETGRAPH);
return (error);
}
if ((q = ng_getqblk()) == NULL) {
FREE(msg, M_NETGRAPH);
if (retaddr)
FREE(retaddr, M_NETGRAPH);
return (ENOBUFS);
}
/* Fill out the contents */
q->flags = NGQF_MESG;
q->next = NULL;
q->body.msg.msg_node = dest;
q->body.msg.msg_msg = msg;
q->body.msg.msg_retaddr = retaddr;
dest->refs++; /* don't let it go away while on the queue */
/* Put it on the queue */
s = splhigh();
if (ngqbase) {
ngqlast->next = q;
} else {
ngqbase = q;
}
ngqlast = q;
ngqsize++;
splx(s);
/* Schedule software interrupt to handle it later */
schednetisr(NETISR_NETGRAPH);
return (0);
}
/*
* Pick an item off the queue, process it, and dispose of the queue entry.
* Should be running at splnet.
*/
static void
ngintr(void)
{
hook_p hook;
struct ng_queue_entry *ngq;
struct mbuf *m;
meta_p meta;
void *retaddr;
struct ng_mesg *msg;
node_p node;
int error = 0;
int s;
while (1) {
s = splhigh();
if ((ngq = ngqbase)) {
ngqbase = ngq->next;
ngqsize--;
}
splx(s);
if (ngq == NULL)
return;
switch (ngq->flags) {
case NGQF_DATA:
hook = ngq->body.data.da_hook;
m = ngq->body.data.da_m;
meta = ngq->body.data.da_meta;
RETURN_QBLK(ngq);
NG_SEND_DATAQ(error, hook, m, meta);
ng_unref_hook(hook);
break;
case NGQF_MESG:
node = ngq->body.msg.msg_node;
msg = ngq->body.msg.msg_msg;
retaddr = ngq->body.msg.msg_retaddr;
RETURN_QBLK(ngq);
if (node->flags & NG_INVALID) {
FREE(msg, M_NETGRAPH);
} else {
CALL_MSG_HANDLER(error, node, msg,
retaddr, NULL);
}
ng_unref(node);
if (retaddr)
FREE(retaddr, M_NETGRAPH);
break;
default:
RETURN_QBLK(ngq);
}
}
}
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