/* * 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 * Archie Cobbs * * $FreeBSD$ * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $ */ /* * This file implements the base netgraph code. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE_VERSION(netgraph, 1); /* List of all active nodes */ static LIST_HEAD(, ng_node) ng_nodelist; static struct mtx ng_nodelist_mtx; #ifdef NETGRAPH_DEBUG 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 */ /* List nodes with unallocated work */ static TAILQ_HEAD(, ng_node) ng_worklist = TAILQ_HEAD_INITIALIZER(ng_worklist); static struct mtx ng_worklist_mtx; /* List of installed types */ static LIST_HEAD(, ng_type) ng_typelist; static struct mtx ng_typelist_mtx; /* Hash related definitions */ /* Don't nead to initialise them because it's a LIST */ #define ID_HASH_SIZE 32 /* most systems wont need even this many */ static LIST_HEAD(, ng_node) ng_ID_hash[ID_HASH_SIZE]; static struct mtx ng_idhash_mtx; /* Mutex that protects the free queue item list */ static volatile item_p ngqfree; /* free ones */ static struct mtx ngq_mtx; /* 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, 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); 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); /* imported , these used to be externally visible, some may go back */ int ng_bypass(hook_p hook1, hook_p hook2); void ng_cutlinks(node_p node); int ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2); 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); struct ng_type *ng_findtype(const char *type); int ng_make_node(const char *type, node_p *nodepp); int ng_mkpeer(node_p node, const char *name, const char *name2, char *type); int ng_path_parse(char *addr, char **node, char **path, char **hook); void ng_rmnode(node_p node); 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_META, "netgraph_meta", "netgraph name storage"); 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_enter(&ng_nodelist_mtx, MTX_DEF); 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_exit(&ng_nodelist_mtx, MTX_DEF); hook->hk_magic = HK_MAGIC; } else { mtx_exit(&ng_nodelist_mtx, MTX_DEF); _NG_ALLOC_HOOK(hook); if (hook) { hook->hk_magic = HK_MAGIC; mtx_enter(&ng_nodelist_mtx, MTX_DEF); SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all); mtx_exit(&ng_nodelist_mtx, MTX_DEF); } } return (hook); } static __inline node_p ng_alloc_node(void) { node_p node; SLIST_ENTRY(ng_node) temp; mtx_enter(&ng_nodelist_mtx, MTX_DEF); 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_exit(&ng_nodelist_mtx, MTX_DEF); node->nd_magic = ND_MAGIC; } else { mtx_exit(&ng_nodelist_mtx, MTX_DEF); _NG_ALLOC_NODE(node); if (node) { node->nd_magic = ND_MAGIC; mtx_enter(&ng_nodelist_mtx, MTX_DEF); SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all); mtx_exit(&ng_nodelist_mtx, MTX_DEF); } } 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_enter(&ng_nodelist_mtx, MTX_DEF); \ LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks); \ hook->hk_magic = 0; \ mtx_exit(&ng_nodelist_mtx, MTX_DEF); \ } while (0) #define NG_FREE_NODE(node) \ do { \ mtx_enter(&ng_nodelist_mtx, MTX_DEF); \ LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes); \ node->nd_magic = 0; \ mtx_exit(&ng_nodelist_mtx, MTX_DEF); \ } 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 */ /*----------------------------------------------*/ /* Warning: Generally use NG_FREE_ITEM() instead */ #define NG_FREE_ITEM_REAL(item) do { FREE((item), M_NETGRAPH_ITEM); } while (0) /* 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; #ifdef INVARIANTS #define CHECK_DATA_MBUF(m) do { \ struct mbuf *n; \ int total; \ \ if (((m)->m_flags & M_PKTHDR) == 0) \ panic("%s: !PKTHDR", __FUNCTION__); \ for (total = 0, n = (m); n != NULL; n = n->m_next) \ total += n->m_len; \ if ((m)->m_pkthdr.len != total) { \ panic("%s: %d != %d", \ __FUNCTION__, (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_info \ ng_ ## lo ## _type_info = NG_GENERIC_ ## up ## _INFO args; \ static const struct ng_parse_type ng_generic_ ## lo ## _type = { \ &ng_parse_struct_type, \ &ng_ ## lo ## _type_info \ } 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 preceeding 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 ((type = ng_findtype(typename)) == NULL) { char 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", typename); error = linker_load_file(filename, &lf); 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); } /* * 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 acency 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, "netgraph node mutex", 0); 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_enter(&ng_nodelist_mtx, MTX_DEF); LIST_INSERT_HEAD(&ng_nodelist, node, nd_nodes); mtx_exit(&ng_nodelist_mtx, MTX_DEF); /* get an ID and put us in the hash chain */ mtx_enter(&ng_idhash_mtx, MTX_DEF); 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? */ if ((node->nd_ID == 0) || (node2 = ng_ID2noderef(node->nd_ID))) { if (node2) { NG_NODE_UNREF(node2); node2 = NULL; } } else { break; } } LIST_INSERT_HEAD(&ng_ID_hash[node->nd_ID % ID_HASH_SIZE], node, nd_idnodes); mtx_exit(&ng_idhash_mtx, MTX_DEF); /* 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. * * Persistent node types must have a type-specific method which * Allocates a new node. This one is irretrievably going away. */ void ng_rmnode(node_p node) { /* Check if it's already shutting down */ if ((node->nd_flags & NG_CLOSING) != 0) 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 NG_INVALID does not do this as it's also set during * creation */ node->nd_flags |= NG_INVALID|NG_CLOSING; ng_cutlinks(node); /* * 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. */ ng_flush_input_queue(&node->nd_input_queue); /* * Take us off the work queue if we are there. * We definatly have no work to be done. */ ng_worklist_remove(node); /* 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); } else { /* do the default thing */ NG_NODE_UNREF(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. * XXX we need a way to tell the node * "No, really.. the hardware's going away.. REALLY die" * We need a way */ return; } 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); } /* * Called by the destructor to remove any STANDARD external references * May one day have it's own message to call it.. */ void ng_cutlinks(node_p node) { hook_p hook; /* Make sure that this is set to stop infinite loops */ node->nd_flags |= NG_INVALID; /* * Drain the input queue forceably. * We also do this in ng_rmnode * to make sure we get all code paths. */ ng_flush_input_queue(&node->nd_input_queue); /* Notify all remaining connected nodes to disconnect */ while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL) ng_destroy_hook(hook); } /* * Remove a reference to the node, possibly the last */ void ng_unref_node(node_p node) { int v; do { v = node->nd_refs; } while (! atomic_cmpset_int(&node->nd_refs, v, v - 1)); if (v == 1) { /* we were the last */ mtx_enter(&ng_nodelist_mtx, MTX_DEF); node->nd_type->refs--; /* XXX maybe should get types lock? */ LIST_REMOVE(node, nd_nodes); mtx_exit(&ng_nodelist_mtx, MTX_DEF); mtx_enter(&ng_idhash_mtx, MTX_DEF); LIST_REMOVE(node, nd_idnodes); mtx_exit(&ng_idhash_mtx, MTX_DEF); mtx_destroy(&node->nd_input_queue.q_mtx); NG_FREE_NODE(node); } } /************************************************************************ Node ID handling ************************************************************************/ static node_p ng_ID2noderef(ng_ID_t ID) { node_p node; mtx_enter(&ng_idhash_mtx, MTX_DEF); LIST_FOREACH(node, &ng_ID_hash[ID % ID_HASH_SIZE], nd_idnodes) { if (NG_NODE_IS_VALID(node) && (NG_NODE_ID(node) == ID)) { break; } } if(node) NG_NODE_REF(node); mtx_exit(&ng_idhash_mtx, MTX_DEF); 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_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 name isn't already being used */ if ((node2 = ng_name2noderef(node, name)) != NULL) { NG_NODE_UNREF(node2); TRAP_ERROR; return (EADDRINUSE); } /* copy it */ strncpy(NG_NODE_NAME(node), name, NG_NODELEN); 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_enter(&ng_nodelist_mtx, MTX_DEF); 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_exit(&ng_nodelist_mtx, MTX_DEF); 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) { 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. */ void ng_unname(node_p node) { bzero(NG_NODE_NAME(node), NG_NODELEN); } /************************************************************************ Hook routines Names are not optional. Hooks are always connected, except for a brief moment within these routines. ************************************************************************/ /* * Remove a hook reference */ void ng_unref_hook(hook_p hook) { int v; 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)) { 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. */ 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; hook->hk_flags = HK_INVALID; hook->hk_node = node; NG_NODE_REF(node); /* each hook counts as a reference */ /* Check if the node type code has something to say about it */ if (node->nd_type->newhook != NULL) if ((error = (*node->nd_type->newhook)(node, hook, name)) != 0) { 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. * The reference we have is for this linkage. */ LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks); node->nd_numhooks++; /* Set hook name */ strncpy(NG_HOOK_NAME(hook), name, NG_HOOKLEN); 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->hk_peer = hook2; hook2->hk_peer = hook1; /* Give each node the opportunity to veto the impending connection */ if (hook1->hk_node->nd_type->connect) { if ((error = (*hook1->hk_node->nd_type->connect) (hook1))) { ng_destroy_hook(hook1); /* also zaps hook2 */ return (error); } } if (hook2->hk_node->nd_type->connect) { if ((error = (*hook2->hk_node->nd_type->connect) (hook2))) { ng_destroy_hook(hook2); /* also zaps hook1 */ return (error); } } hook1->hk_flags &= ~HK_INVALID; hook2->hk_flags &= ~HK_INVALID; 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. */ 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. */ void ng_destroy_hook(hook_p hook) { hook_p peer = NG_HOOK_PEER(hook); hook->hk_flags |= HK_INVALID; /* as soon as possible */ if (peer) { peer->hk_flags |= HK_INVALID; /* as soon as possible */ hook->hk_peer = NULL; peer->hk_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 = NG_HOOK_NODE(hook); /* * Remove the hook from the node's list to avoid possible recursion * in case the disconnection results in node shutdown. */ LIST_REMOVE(hook, hk_hooks); node->nd_numhooks--; if (node->nd_type->disconnect) { /* * The type handler may elect to destroy the peer so don't * trust its existance after this point. */ (*node->nd_type->disconnect) (hook); } NG_HOOK_UNREF(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->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; /* XXX If we ever cache methods on hooks update them as well */ hook1->hk_peer = NULL; hook2->hk_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_ABI_VERSION) || (namelen == 0) || (namelen > NG_TYPELEN)) { TRAP_ERROR; return (EINVAL); } /* Check for name collision */ if (ng_findtype(tp->name) != NULL) { TRAP_ERROR; return (EEXIST); } tp->refs = 0; /* Link in new type */ mtx_enter(&ng_typelist_mtx, MTX_DEF); LIST_INSERT_HEAD(&ng_typelist, tp, types); mtx_exit(&ng_typelist_mtx, MTX_DEF); return (0); } /* * Look for a type of the name given */ struct ng_type * ng_findtype(const char *typename) { struct ng_type *type; mtx_enter(&ng_typelist_mtx, MTX_DEF); LIST_FOREACH(type, &ng_typelist, types) { if (strcmp(type->name, typename) == 0) break; } mtx_exit(&ng_typelist_mtx, MTX_DEF); 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)); } /************************************************************************ Utility routines to send self messages ************************************************************************/ /* * Static version of shutdown message. we don't want to need resources * to shut down (we may be doing it to release resources because we ran out. */ static struct ng_mesg ng_msg_shutdown = { {NG_VERSION, /* u_char */ 0, /* u_char spare */ 0, /* u_int16_t arglen */ NGF_STATIC, /* u_int32_t flags */ 0, /* u_int32_t token */ NGM_GENERIC_COOKIE, /* u_int32_t */ NGM_SHUTDOWN, /* u_int32_t */ "shutdown"} /* u_char[16] */ }; int ng_rmnode_self(node_p here) { item_p item; struct ng_mesg *msg; /* * Use the static version to avoid needing * memory allocation to succeed. * The message is never written to and always the same. */ msg = &ng_msg_shutdown; /* * Try get a queue item to send it with. * Hopefully since it has a reserve, we can get one. * If we can't we are screwed anyhow. * Increase the chances by flushing our queue first. * We may free an item, (if we were the hog). * Work in progress is allowed to complete. * We also pretty much ensure that we come straight * back in to do the shutdown. It may be a good idea * to hold a reference actually to stop it from all * going up in smoke. */ /* ng_flush_input_queue(&here->nd_input_queue); will mask problem */ item = ng_package_msg_self(here, NULL, msg); if (item == NULL) { /* it would have freed the msg except static */ /* try again after flushing our queue */ ng_flush_input_queue(&here->nd_input_queue); item = ng_package_msg_self(here, NULL, msg); if (item == NULL) { printf("failed to free node 0x%x\n", ng_node2ID(here)); return (ENOMEM); } } return (ng_snd_item(item, 0)); } /*********************************************************************** * Parse and verify a string of the form: * * 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 and are optional. The 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 , 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_PATHLEN + 1]; 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); 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 is important! don't shuffle these. If you add * READ_PENDING to the word when it has READ_PENDING already set, you * generate a carry into the reader count, this you atomically add a reader, * and remove the pending reader count! Similarly for the pending writer * flag, adding WRITE_PENDING generates a carry and sets the WRITER_ACTIVE * flag, while clearing WRITE_PENDING. When 'SINGLE_THREAD_ONLY' is set, then * it is only permitted to do WRITER operations. Reader operations will * result in errors. * But that "hack" is unnecessary: "cpp" can do the math for us! */ /*- 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| | | | | | | | | |R|A|W|S| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |P|W|P|T| +-------+-------+-------+-------+-------+-------+-------+-------+ \_________________________ ____________________________/ | | | | V | | | | [active reader count] | | | | | | | | Read Pending ------------------------------------+ | | | | | | Active Writer -------------------------------------+ | | | | Write Pending ---------------------------------------+ | | Single Threading Only ---------------------------------+ */ #define SINGLE_THREAD_ONLY 0x00000001 /* if set, even reads single thread */ #define WRITE_PENDING 0x00000002 #define WRITER_ACTIVE 0x00000004 #define READ_PENDING 0x00000008 #define READER_INCREMENT 0x00000010 #define READER_MASK 0xfffffff0 /* Not valid if WRITER_ACTIVE is set */ #define SAFETY_BARRIER 0x00100000 /* 64K items queued should be enough */ /* * 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) { item_p item; u_int add_arg; /* * If there is a writer, then the answer is "no". Everything else * stops when there is a WRITER. */ if (ngq->q_flags & WRITER_ACTIVE) { return (NULL); } /* Now take a look at what's on the queue and what's running */ if ((ngq->q_flags & ~(READER_MASK | SINGLE_THREAD_ONLY)) == READ_PENDING) { /* * It was a reader and we have no write active. We don't care * how many readers are already active. Adjust the count for * the item we are about to dequeue. Adding READ_PENDING to * the exisiting READ_PENDING clears it and generates a carry * into the reader count. */ add_arg = READ_PENDING; } else if ((ngq->q_flags & ~SINGLE_THREAD_ONLY) == WRITE_PENDING) { /* * 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 WRITE_PENDING flag * will make it fail, and if it tests it later, the * ACTIVE_WRITER flag will do the same. If it is SO slow that * we have actually completed the operation, and neither flag * is set (nor the READ_PENDING) 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 wil be * set. */ /* * Adjust the flags for the item we are about to dequeue. * Adding WRITE_PENDING to the exisiting WRITE_PENDING clears * it and generates a carry into the WRITER_ACTIVE flag, all * atomically. */ add_arg = WRITE_PENDING; /* * 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 through in just a moment, (as soon * as we release the mutex) and keep things moving. */ return (0); } /* * 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 flags are * clear. */ ngq->last = &(ngq->queue); /* * Whatever flag was set is cleared and the carry sets the * correct new active state/count. So we don't need to change * add_arg. */ } else { if ((ngq->queue->el_flags & NGQF_TYPE) == NGQF_READER) { /* * If we had a READ_PENDING and have another one, we * just want to add READ_PENDING twice (the same as * adding READER_INCREMENT). If we had WRITE_PENDING, * we want to add READ_PENDING + WRITE_PENDING to * clear the old WRITE_PENDING, set ACTIVE_WRITER, * and set READ_PENDING. Either way we just add * READ_PENDING to whatever we already had. */ add_arg += READ_PENDING; } else { /* * If we had a WRITE_PENDING and have another one, we * just want to add WRITE_PENDING twice (the same as * adding ACTIVE_WRITER). If we had READ_PENDING, we * want to add READ_PENDING + WRITE_PENDING to clear * the old READ_PENDING, increment the readers, and * set WRITE_PENDING. Either way we just add * WRITE_PENDING to whatever we already had. */ add_arg += WRITE_PENDING; } } atomic_add_long(&ngq->q_flags, add_arg); /* * We have successfully cleared the old pending flag, set the new one * if it is needed, and incremented the appropriate active field. * (all in one atomic addition.. wow) */ 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.. * 1 = writer, 0 = reader * We should set something to indicate NETISR requested * If it's the first item queued. */ #define NGQRW_R 0 #define NGQRW_W 1 static __inline void ng_queue_rw(struct ng_queue * ngq, item_p item, int rw) { 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)) { /* * When called with constants for rw, the optimiser will * remove the unneeded branch below. */ if (rw == NGQRW_W) { atomic_add_long(&ngq->q_flags, WRITE_PENDING); } else { atomic_add_long(&ngq->q_flags, READ_PENDING); } } ngq->last = &(item->el_next); } /* * 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) { /* ######### Hack alert ######### */ atomic_add_long(&ngq->q_flags, READER_INCREMENT); if ((ngq->q_flags & (~READER_MASK)) == 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_enter((&ngq->q_mtx), MTX_SPIN); /* * 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.) */ if ((ngq->q_flags & (~READER_MASK)) == 0) { atomic_add_long(&ngq->q_flags, READER_INCREMENT); mtx_exit((&ngq->q_mtx), MTX_SPIN); return (item); } /* * Quick check that we are doing things right. */ if (ngq->q_flags & SINGLE_THREAD_ONLY) { panic("Calling single treaded queue incorrectly"); } /* * and queue the request for later. */ item->el_flags |= NGQF_TYPE; ng_queue_rw(ngq, item, NGQRW_R); /* * Ok, so that's the item successfully queued for later. So now we * see if we can dequeue something to run instead. */ item = ng_dequeue(ngq); mtx_exit(&(ngq->q_mtx), MTX_SPIN); return (item); } static __inline item_p ng_acquire_write(struct ng_queue *ngq, item_p item) { restart: mtx_enter(&(ngq->q_mtx), MTX_SPIN); /* * 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 & (~SINGLE_THREAD_ONLY)) == 0) { atomic_add_long(&ngq->q_flags, WRITER_ACTIVE); mtx_exit((&ngq->q_mtx), MTX_SPIN); if (ngq->q_flags & READER_MASK) { /* Collision with fast-track reader */ atomic_add_long(&ngq->q_flags, -WRITER_ACTIVE); goto restart; } return (item); } /* * and queue the request for later. */ item->el_flags &= ~NGQF_TYPE; ng_queue_rw(ngq, item, NGQRW_W); /* * Ok, so that's the item successfully queued for later. So now we * see if we can dequeue something to run instead. */ item = ng_dequeue(ngq); mtx_exit(&(ngq->q_mtx), MTX_SPIN); return (item); } 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; u_int add_arg; mtx_enter(&ngq->q_mtx, MTX_SPIN); for (;;) { /* Now take a look at what's on the queue */ if (ngq->q_flags & READ_PENDING) { add_arg = -READ_PENDING; } else if (ngq->q_flags & WRITE_PENDING) { add_arg = -WRITE_PENDING; } else { break; } item = ngq->queue; ngq->queue = item->el_next; if (ngq->last == &(item->el_next)) { ngq->last = &(ngq->queue); } else { if ((ngq->queue->el_flags & NGQF_TYPE) == NGQF_READER) { add_arg += READ_PENDING; } else { add_arg += WRITE_PENDING; } } atomic_add_long(&ngq->q_flags, add_arg); mtx_exit(&ngq->q_mtx, MTX_SPIN); NG_FREE_ITEM(item); mtx_enter(&ngq->q_mtx, MTX_SPIN); } mtx_exit(&ngq->q_mtx, MTX_SPIN); } /*********************************************************************** * Externally visible method for sending or queueing messages or data. ***********************************************************************/ /* * MACRO WILL DO THE JOB OF CALLING ng_package_msg IN CALLER * before we are called. The user 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 * pointer to metadata * Control_Message: * pointer to msg. * ID of original sender node. (return address) * * The nodes have several routines and macros to help with this task: * ng_package_msg() * ng_package_data() do much of the work. * ng_retarget_msg * ng_retarget_data */ int ng_snd_item(item_p item, int queue) { hook_p hook = item->el_hook; node_p dest = item->el_dest; int rw; int error = 0, ierror; item_p oitem; struct ng_queue * ngq = &dest->nd_input_queue; #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif if (item == NULL) { TRAP_ERROR; return (EINVAL); /* failed to get queue element */ } if (dest == NULL) { NG_FREE_ITEM(item); TRAP_ERROR; return (EINVAL); /* No address */ } if ((item->el_flags & NGQF_D_M) == 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. */ #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif 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; } /* By default data is a reader in the locking scheme */ item->el_flags |= NGQF_READER; rw = NGQRW_R; } else { /* * 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; } /* Data messages count as writers unles explicitly exempted */ if (NGI_MSG(item)->header.cmd & NGM_READONLY) { item->el_flags |= NGQF_READER; rw = NGQRW_R; } else { item->el_flags &= ~NGQF_TYPE; rw = NGQRW_W; } } /* * If the node specifies single threading, force writer semantics * Similarly the node may say one hook always produces writers. * These are over-rides. */ if ((ngq->q_flags & SINGLE_THREAD_ONLY) || (dest->nd_flags & NG_FORCE_WRITER) || (hook && (hook->hk_flags & HK_FORCE_WRITER))) { rw = NGQRW_W; item->el_flags &= ~NGQF_TYPE; } if (queue) { /* Put it on the queue for that node*/ #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif mtx_enter(&(ngq->q_mtx), MTX_SPIN); ng_queue_rw(ngq, item, rw); mtx_exit(&(ngq->q_mtx), MTX_SPIN); /* * If there are active elements then we can rely on * them. if not we should not rely on another packet * coming here by another path, * so it is best to put us in the netisr list. */ if ((ngq->q_flags & (READER_MASK|WRITER_ACTIVE)) == 0) { ng_setisr(ngq->q_node); } return (0); } /* * Take a queue item and a node and see if we can apply the item to * the node. We may end up getting a different item to apply instead. * Will allow for a piggyback reply only in the case where * there is no queueing. */ oitem = item; /* * 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); } /* * May have come back with a different item. * or maybe none at all. The one we started with will * have been queued in thises cases. */ if (item == NULL) { return (0); } #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif ierror = ng_apply_item(dest, item); /* drops r/w lock when done */ /* only return an error if it was our initial item.. (compat hack) */ if (oitem == item) { error = ierror; } /* * Now we've handled the packet we brought, (or a friend of it) let's * look for any other packets that may have been queued up. We hold * no locks, so if someone puts something in the queue after * we check that it is empty, it is their problem * to ensure it is processed. If we have the netisr thread cme in here * while we still say we have stuff to do, we may get a boost * in SMP systems. :-) */ for (;;) { /* quick hack to save all that mutex stuff */ if ((ngq->q_flags & (WRITE_PENDING | READ_PENDING)) == 0) { if (dest->nd_flags & NG_WORKQ) ng_worklist_remove(dest); return (0); } /* * dequeue acquires and adjusts the input_queue as it dequeues * packets. It acquires the rw lock as needed. */ mtx_enter(&ngq->q_mtx, MTX_SPIN); item = ng_dequeue(ngq); mtx_exit(&ngq->q_mtx, MTX_SPIN); if (!item) { /* * If we have no work to do * then we certainly don't need to be * on the worklist. */ if (dest->nd_flags & NG_WORKQ) ng_worklist_remove(dest); return (0); } #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif /* * We have the appropriate lock, so run the item. * When finished it will drop the lock accordingly */ ierror = ng_apply_item(dest, item); /* * only return an error if it was our initial * item.. (compat hack) */ if (oitem == item) { error = ierror; } } return (0); } /* * 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) { hook_p hook; int was_reader = ((item->el_flags & NGQF_TYPE)); int error = 0; ng_rcvdata_t *rcvdata; hook = item->el_hook; item->el_hook = NULL; /* so NG_FREE_ITEM doesn't NG_HOOK_UNREF() */ /* We already have the node.. assume responsibility */ /* And the reference */ /* node = item->el_dest; */ item->el_dest = NULL; /* same as for the hook above */ #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif switch (item->el_flags & NGQF_D_M) { 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(NG_HOOK_NODE(hook)) || ((rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata) == NULL)) { error = EIO; NG_FREE_ITEM(item); } else { error = (*rcvdata)(hook, item); } break; case NGQF_MESG: if (hook) { item->el_hook = NULL; if (NG_HOOK_NOT_VALID(hook)) { /* * If 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); if ((msg->header.typecookie == NGM_GENERIC_COOKIE) && ((msg->header.flags & NGF_RESP) == 0)) { error = ng_generic_msg(node, item, hook); } else { if ((node)->nd_type->rcvmsg != NULL) { error = (*(node)->nd_type->rcvmsg)((node), (item), (hook)); } else { TRAP_ERROR; error = EINVAL; /* XXX */ NG_FREE_ITEM(item); } } /* item is now invalid */ } 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 (was_reader) { ng_leave_read(&node->nd_input_queue); } else { ng_leave_write(&node->nd_input_queue); } NG_NODE_UNREF(node); 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); 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)) strncpy(ni->name, NG_NODE_NAME(here), NG_NODELEN); strncpy(ni->type, here->nd_type->name, NG_TYPELEN); 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)) strncpy(ni->name, NG_NODE_NAME(here), NG_NODELEN); strncpy(ni->type, here->nd_type->name, NG_TYPELEN); 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", __FUNCTION__, "hooks"); break; } if (NG_HOOK_NOT_VALID(hook)) continue; strncpy(link->ourhook, NG_HOOK_NAME(hook), NG_HOOKLEN); strncpy(link->peerhook, NG_PEER_HOOK_NAME(hook), NG_HOOKLEN); if (NG_PEER_NODE_NAME(hook)[0] != '\0') strncpy(link->nodeinfo.name, NG_PEER_NODE_NAME(hook), NG_NODELEN); strncpy(link->nodeinfo.type, NG_PEER_NODE(hook)->nd_type->name, NG_TYPELEN); 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_enter(&ng_nodelist_mtx, MTX_DEF); /* 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_exit(&ng_nodelist_mtx, MTX_DEF); /* 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_enter(&ng_nodelist_mtx, MTX_DEF); 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", __FUNCTION__, "nodes"); break; } if (NG_NODE_NOT_VALID(node)) continue; if (!unnamed && (! NG_NODE_HAS_NAME(node))) continue; if (NG_NODE_HAS_NAME(node)) strncpy(np->name, NG_NODE_NAME(node), NG_NODELEN); strncpy(np->type, node->nd_type->name, NG_TYPELEN); np->id = ng_node2ID(node); np->hooks = node->nd_numhooks; nl->numnames++; } mtx_exit(&ng_nodelist_mtx, MTX_DEF); break; } case NGM_LISTTYPES: { struct typelist *tl; struct ng_type *type; int num = 0; mtx_enter(&ng_typelist_mtx, MTX_DEF); /* Count number of types */ LIST_FOREACH(type, &ng_typelist, types) { num++; } mtx_exit(&ng_typelist_mtx, MTX_DEF); /* 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_enter(&ng_typelist_mtx, MTX_DEF); 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", __FUNCTION__, "types"); break; } strncpy(tp->type_name, type->name, NG_TYPELEN); tp->numnodes = type->refs; tl->numtypes++; } mtx_exit(&ng_typelist_mtx, MTX_DEF); 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 && ((msg->header.flags & NGF_STATIC) == 0)) NG_FREE_MSG(msg); return (error); } /* * Copy a 'meta'. * * Returns new meta, or NULL if original meta is NULL or ENOMEM. */ meta_p ng_copy_meta(meta_p meta) { meta_p meta2; if (meta == NULL) return (NULL); MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH_META, M_NOWAIT); if (meta2 == NULL) return (NULL); meta2->allocated_len = meta->used_len; bcopy(meta, meta2, meta->used_len); return (meta2); } /************************************************************************ 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_enter(&ng_typelist_mtx, MTX_DEF); LIST_REMOVE(type, types); mtx_exit(&ng_typelist_mtx, MTX_DEF); } 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; } } mtx_enter(&ng_typelist_mtx, MTX_DEF); LIST_REMOVE(type, types); mtx_exit(&ng_typelist_mtx, MTX_DEF); } 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 */ mtx_init(&ng_worklist_mtx, "netgraph worklist mutex", 0); mtx_init(&ng_typelist_mtx, "netgraph types mutex", 0); mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", 0); mtx_init(&ng_idhash_mtx, "netgraph idhash mutex", 0); mtx_init(&ngq_mtx, "netgraph netisr mutex", 0); 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); /************************************************************************ Queue element get/free routines ************************************************************************/ static int allocated; /* number of items malloc'd */ static int maxalloc = 128; /* limit the damage of a leak */ static const int ngqfreemax = 64;/* cache at most this many */ static const int ngqfreelow = 4; /* try malloc if free < this */ static volatile int ngqfreesize; /* number of cached entries */ #ifdef NETGRAPH_DEBUG static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist); #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. Use atomic operations to cope with collisions * with interrupts and other processors. Assumes MALLOC is SMP safe. * XXX If reserve is low, we should try to get 2 from malloc as this * would indicate it often fails. */ static item_p ng_getqblk(void) { item_p item = NULL; /* * Try get a cached queue block, or else allocate a new one * If we are less than our reserve, try malloc. If malloc * fails, then that's what the reserve is for... * Don't completely trust ngqfreesize, as it is subject * to races.. (it'll eventually catch up but may be out by one or two * for brief moments(under SMP or interrupts). * ngqfree is the final arbiter. We have our little reserve * because we use M_NOWAIT for malloc. This just helps us * avoid dropping packets while not increasing the time * we take to service the interrupt (on average) (we hope). */ for (;;) { if ((ngqfreesize < ngqfreelow) || (ngqfree == NULL)) { if (allocated < maxalloc) { /* don't leak forever */ MALLOC(item, item_p , sizeof(*item), M_NETGRAPH_ITEM, (M_NOWAIT | M_ZERO)); if (item) { #ifdef NETGRAPH_DEBUG TAILQ_INSERT_TAIL(&ng_itemlist, item, all); #endif /* NETGRAPH_DEBUG */ atomic_add_int(&allocated, 1); break; } } } /* * We didn't or couldn't malloc. * try get one from our cache. * item must be NULL to get here. */ if ((item = ngqfree) != NULL) { /* * Atomically try grab the first item * and put it's successor in its place. * If we fail, just try again.. someone else * beat us to this one or freed one. * Don't worry about races with ngqfreesize. * Close enough is good enough.. */ if (atomic_cmpset_ptr(&ngqfree, item, item->el_next)) { atomic_subtract_int(&ngqfreesize, 1); break; } item = NULL; } else { /* We really ran out */ break; } } item->el_flags &= ~NGQF_FREE; return (item); } /* * Release a queue entry */ void ng_free_item(item_p item) { /* * 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. */ if (item->el_flags & NGQF_FREE) { panic(" Freeing free queue item"); } switch (item->el_flags & NGQF_D_M) { case NGQF_DATA: /* If we have an mbuf and metadata still attached.. */ NG_FREE_M(_NGI_M(item)); NG_FREE_META(_NGI_META(item)); break; case NGQF_MESG: _NGI_RETADDR(item) = NULL; NG_FREE_MSG(_NGI_MSG(item)); break; } /* If we still have a node or hook referenced... */ if (item->el_dest) { NG_NODE_UNREF(item->el_dest); item->el_dest = NULL; } if (item->el_hook) { NG_HOOK_UNREF(item->el_hook); item->el_hook = NULL; } item->el_flags |= NGQF_FREE; /* * We have freed any resources held by the item. * now we can free the item itself. */ if (ngqfreesize < ngqfreemax) { /* don't worry about races */ for (;;) { item->el_next = ngqfree; if (atomic_cmpset_ptr(&ngqfree, item->el_next, item)) { break; } } atomic_add_int(&ngqfreesize, 1); } else { /* This is the only place that should use this Macro */ #ifdef NETGRAPH_DEBUG TAILQ_REMOVE(&ng_itemlist, item, all); #endif /* NETGRAPH_DEBUG */ NG_FREE_ITEM_REAL(item); atomic_subtract_int(&allocated, 1); } } #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_node2ID(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) { if (item->el_flags & NGQF_FREE) { printf(" Free item, freed at %s, line %d\n", item->lastfile, item->lastline); } else { printf(" ACTIVE item, last used at %s, line %d", item->lastfile, item->lastline); if ((item->el_flags & NGQF_D_M) == NGQF_MESG) { printf(" - retaddr[%d]:\n", _NGI_RETADDR(item)); } else { printf(" - [data]\n"); } } if (line) { printf(" problem discovered at file %s, line %d\n", file, line); if (item->el_dest) { printf("node %p ([%x])\n", item->el_dest, ng_node2ID(item->el_dest)); } } } 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; SLIST_FOREACH(node, &ng_allnodes, nd_all) { printf("[%d] ", i++); dumpnode(node, NULL, 0); } } static void ng_dumphooks(void) { hook_p hook; int i = 1; SLIST_FOREACH(hook, &ng_allhooks, hk_all) { printf("[%d] ", i++); dumphook(hook, NULL, 0); } } static int sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS) { static int count; int error; int val; int i; val = allocated; i = 1; error = sysctl_handle_int(oidp, &val, sizeof(int), req); if(count++ & 1) { /* for some reason sysctl calls it twice */ ng_dumpitems(); ng_dumpnodes(); ng_dumphooks(); } return error; } SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RD, 0, 0, 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_enter(&ng_worklist_mtx, MTX_SPIN); node = TAILQ_FIRST(&ng_worklist); if (!node) { mtx_exit(&ng_worklist_mtx, MTX_SPIN); break; } TAILQ_REMOVE(&ng_worklist, node, nd_work); mtx_exit(&ng_worklist_mtx, MTX_SPIN); /* * 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. */ for (;;) { mtx_enter(&node->nd_input_queue.q_mtx, MTX_SPIN); item = ng_dequeue(&node->nd_input_queue); if (item == NULL) { /* * Say we are on the queue as long as * we are processing it here. * it probably wouldn't come here while we * are processing anyhow. */ node->nd_flags &= ~NG_WORKQ; mtx_exit(&node->nd_input_queue.q_mtx, MTX_SPIN); NG_NODE_UNREF(node); break; /* go look for another node */ } else { mtx_exit(&node->nd_input_queue.q_mtx, MTX_SPIN); #ifdef NETGRAPH_DEBUG _ngi_check(item, __FILE__, __LINE__); #endif ng_apply_item(node, item); } } } } static void ng_worklist_remove(node_p node) { mtx_enter(&ng_worklist_mtx, MTX_SPIN); if (node->nd_flags & NG_WORKQ) { TAILQ_REMOVE(&ng_worklist, node, nd_work); NG_NODE_UNREF(node); } node->nd_flags &= ~NG_WORKQ; mtx_exit(&ng_worklist_mtx, MTX_SPIN); } static void ng_setisr(node_p node) { mtx_enter(&ng_worklist_mtx, MTX_SPIN); if ((node->nd_flags & NG_WORKQ) == 0) { /* * If we are not already on the work queue, * then put us on. */ node->nd_flags |= NG_WORKQ; TAILQ_INSERT_TAIL(&ng_worklist, node, nd_work); NG_NODE_REF(node); } mtx_exit(&ng_worklist_mtx, MTX_SPIN); schednetisr(NETISR_NETGRAPH); } /*********************************************************************** * Externally useable functions to set up a queue item ready for sending ***********************************************************************/ #ifdef NETGRAPH_DEBUG #define ITEM_DEBUG_CHECKS \ do { \ if (item->el_dest ) { \ printf("item already has node"); \ Debugger("has node"); \ NG_NODE_UNREF(item->el_dest); \ item->el_dest = NULL; \ } \ if (item->el_hook ) { \ printf("item already has hook"); \ Debugger("has hook"); \ NG_HOOK_UNREF(item->el_hook); \ item->el_hook = NULL; \ } \ } while (0) #else #define ITEM_DEBUG_CHECKS #endif /* * Put elements 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 eb 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, meta_p meta) { item_p item; if ((item = ng_getqblk()) == NULL) { NG_FREE_M(m); NG_FREE_META(meta); return (NULL); } ITEM_DEBUG_CHECKS; item->el_flags = NGQF_DATA; item->el_next = NULL; NGI_M(item) = m; NGI_META(item) = meta; 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) { item_p item; if ((item = ng_getqblk()) == NULL) { if ((msg->header.flags & NGF_STATIC) == 0) { NG_FREE_MSG(msg); } return (NULL); } ITEM_DEBUG_CHECKS; item->el_flags = NGQF_MESG; item->el_next = NULL; /* * Set the current lasthook into the queue item */ NGI_MSG(item) = msg; NGI_RETADDR(item) = NULL; return (item); } #define SET_RETADDR \ do { /* Data items don't have retaddrs */ \ if ((item->el_flags & NGQF_D_M) == 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) { 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 (EINVAL); } /* * Transfer our interest to the other (peer) end. */ item->el_hook = NG_HOOK_PEER(hook); NG_HOOK_REF(item->el_hook); /* Don't let it go while on the queue */ item->el_dest = NG_PEER_NODE(hook); NG_NODE_REF(item->el_dest); /* Nor this */ SET_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); } item->el_dest = dest; if (( item->el_hook = hook)) NG_HOOK_REF(hook); /* don't let it go while on the queue */ SET_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 */ item->el_flags = NGQF_MESG; item->el_next = NULL; item->el_dest = dest; item->el_hook = NULL; SET_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()) == NULL) { if ((msg->header.flags & NGF_STATIC) == 0) { NG_FREE_MSG(msg); } return (NULL); } /* Fill out the contents */ item->el_flags = NGQF_MESG; item->el_next = NULL; item->el_dest = here; NG_NODE_REF(here); item->el_hook = hook; if (hook) NG_HOOK_REF(hook); NGI_MSG(item) = msg; NGI_RETADDR(item) = ng_node2ID(here); return (item); } /* * 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; meta_p meta; struct ng_mesg *msg; ng_ID_t retaddr; int error; NGI_GET_M(item, m); NGI_GET_META(item, meta); NGI_GET_MSG(item, msg); retaddr = NGI_RETADDR(item); NG_SEND_DATA(error, hook, m, meta); 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_QUEUE_MSG(error, node, msg, ".:", retaddr); NG_FWD_MSG_HOOK(error, node, item, hook, retaddr); } #endif /* TESTING */