Changeset 1098:f38d77f9cfd3 in freeDiameter

Timestamp:

May 9, 2013, 12:59:34 PM (11 years ago)

Author:

Sebastien Decugis <sdecugis@freediameter.net>

Branch:

default

Phase:

public

Message:

Initial implementation of the hook mechanism

Files:

• include/freeDiameter/freeDiameter-host.h.in (modified) (1 diff)
• include/freeDiameter/libfdcore.h (modified) (12 diffs)
• include/freeDiameter/libfdproto.h (modified) (1 diff)
• libfdcore/cnxctx.c (modified) (1 diff)
• libfdcore/core.c (modified) (1 diff)
• libfdcore/fdcore-internal.h (modified) (1 diff)
• libfdcore/hooks.c (modified) (1 diff)
• libfdproto/messages.c (modified) (3 diffs)

include/freeDiameter/freeDiameter-host.h.in

@@ -95 +95 @@
 #endif /* FD_DEFAULT_CONF_FILENAME */
 
+/* Maximum number of hooks handlers that can be registered. Make this compilation option if needed */
+#define FD_HOOK_HANDLE_LIMIT    5
+
 #ifdef __cplusplus
 }

include/freeDiameter/libfdcore.h

@@ -879 +879 @@
 /* These functions allow an extension to collect state information about the
  * framework, as well as being hooked at some key checkpoints in the processing
- * for logging / statistics purpose.
+ * for logging or statistics purpose.
  */
  
@@ -887 +887 @@
  * PARAMETERS:
  *  type        : The type of hook that triggered this call, in case same cb is registered for several hooks.
- *  msg         : If relevant, the pointer to the message trigging the call. NULL otherwise.
+ *  msg         : If relevant, the pointer to the message triggering the call. NULL otherwise.
  *  peer        : If relevant, the pointer to the peer associated with the call. NULL otherwise.
  *  other       : For some callbacks, the remaining information is passed in this parameter. See each hook detail.
  *  permsgdata  : Structure associated with a given message, across several hooks. 
- *                 Same structure is associated with requests and corresponding answers. 
+ *                 A different structure is associated with requests and corresponding answers. 
  *                 See fd_hook_data_hdl below for details.
  *                 If no fd_hook_data_hdl is registered with this callback, this parameter is always NULL
@@ -916 +916 @@
                  - {msg} is NULL.
                  - {peer} is NULL.
-                 - {*other} is NULL, {other} points to a valid location where you can store a pointer. 
-                    This same pointer will then passed to the next hook, once message is processed.
-                    IMPORTANT: free() will be called on this pointer if any problem, so this pointer must be malloc'd.
-                 - {permsgdata} is NULL.
+                 - {other} is a pointer to a structure { size_t len; uint8_t * buf; } containing the received buffer.
+                 - {permsgdata} points to either a new empty structure allocated for this message (cf. fd_hook_data_hdl), or NULL if no hdl is registered.
                  */
                  
@@ -928 +926 @@
                  - {peer} is set if the message is received from a peer's connection, and NULL if the message is from a new client
                    connected and not yet identified
-                 - {*other} contains the pointer stored with the HOOK_DATA_RECEIVED hook if any, NULL otherwise. After this hook returns, free(*other) is called if not NULL.
-                 - {permsgdata} points to either a new empty structure allocated for this request (cf. fd_hook_data_hdl), or the request's existing structure if the message is an answer.
+                 - {other} is NULL.
+                 - {permsgdata} points to either a new empty structure allocated for this message or the one passed to HOOK_DATA_RECEIVED if used.
                  */
         
@@ -946 +944 @@
                    try to call fd_msg_parse_dict, it will slow down the operation of a relay agent.
                  - {peer} is set if the message is sent to a peer's connection, and NULL if the message is sent to a new client
-                   connected and not yet identified / being rejected
+                   connected and not yet identified, or being rejected
                  - {other} is NULL.
                  - {permsgdata} points to existing structure if any, or a new structure otherwise. 
-                    If the message is an answer, the structure is shared with the corresponding request.
                  */
         
@@ -959 +956 @@
                  - {peer} is the peer this message was previously sent to.
                  - {other} is NULL.
-                 - {permsgdata} points to existing structure associated with this request. 
+                 - {permsgdata} points to existing structure if any, or a new structure otherwise. 
                  */
         
@@ -994 +991 @@
         
         HOOK_MESSAGE_DROPPED,
-                /* Hook called when a message is being discarded by the framework because of some error.
-                   It is probably a good idea to log this for analysis.
+                /* Hook called when a message is being discarded by the framework because of some error condition (normal or abnormal).
+                   It is probably a good idea to log this for analysis / backup.
                  - {msg} points to the message, which will be freed as soon as the hook returns.
                  - {peer} is NULL.
@@ -1022 +1019 @@
 
 
-/* Type if the {permsgdata} ointer. It is up to each extension to define its own structure. This is opaque for the framework. */
+/* Type if the {permsgdata}. It is up to each extension to define its own structure. This is opaque for the framework. */
 struct fd_hook_permsgdata;
 
@@ -1035 +1032 @@
  *
  * PARAMETERS:
- *  permsgdata_new_cb     : function called to initialize a new empty fd_hook_permsgdata structure, when a hook will be called for a message with not structure yet. If the function returns NULL, it will be called again for the next hook.
- *  permsgdata_destroy_cb : function called when a message is being disposed. It should free the resources associated with the fd_hook_permsgdata.
- *  new_handle            : On success, a handler to the registered callback is stored here. 
+ *  permsgdata_size     : the size of the fd_hook_permsgdata structure. 
+ *  permsgdata_init_cb  : function called to initialize a new fd_hook_permsgdata structure, when a hook will be called for a message that does not have such structure yet. 
+ *                           The memory is already allocated and blanked, so you can pass NULL if no further handling is required.
+ *  permsgdata_fini_cb  : function called when a message is being disposed. It should free the resources associated with the fd_hook_permsgdata. 
+ *                           You can pass NULL if no special handling is required. The memory of the permsgdata structure itself will be freed by the framework.
+ *  new_handle          : On success, a handler to the registered callback is stored here. 
  *                           This handler will be used to unregister the cb.
  *
  * DESCRIPTION: 
  *   Register a new fd_hook_data_hdl. This handle is used during hooks registration (see below) in order to associate data with the messages, to allow keeping tracking of the message easily.
- *  Note that these handlers are statically allocated and cannot be unregistered.
+ *  Note that these handlers are statically allocated and cannot be unregistered. FD_HOOK_HANDLE_LIMIT handlers can be registered at maximum (recompile libfdproto if you change this value)
  *
  * RETURN VALUE:
@@ -1050 +1050 @@
  */
 int fd_hook_data_register(
-        struct fd_hook_permsgdata * (*permsgdata_new_cb)     (void),
-        void (*permsgdata_destroy_cb) (struct fd_hook_permsgdata *),
-        struct fd_hook_data_hdl **    new_handle
+        size_t permsgdata_size,
+        void (*permsgdata_init_cb) (struct fd_hook_permsgdata *),
+        void (*permsgdata_fini_cb) (struct fd_hook_permsgdata *),
+        struct fd_hook_data_hdl **new_handle
 );
-
 
 /* A handler associated with a registered hook callback (for cleanup) */
@@ -1063 +1063 @@
  *
  * PARAMETERS:
- *  type          : The fd_hook_type for which this cb is registered. Call several times if you want to register for several hooks.
+ *  type_mask     : A bitmask of fd_hook_type bits for which this cb is registered, e.g. ((1 << HOOK_MESSAGE_RECEIVED) || (1 << HOOK_MESSAGE_SENT))
  *  fd_hook_cb    : The callback function to register (see prototype above).
  *  regdata       : Pointer to pass to the callback when it is called. The data is opaque to the daemon.
@@ -1079 +1079 @@
  *  ENOMEM      : Not enough memory to complete the operation
  */
-int fd_hook_register (  enum fd_hook_type type, 
-                        void (*fd_hook_cb)(enum fd_hook_type type, struct msg * msg, struct peer_hdr * peer, void * other, void * regdata), 
-                        void * regdata, 
+int fd_hook_register (  uint32_t type_mask, 
+                        void (*fd_hook_cb)(enum fd_hook_type type, struct msg * msg, struct peer_hdr * peer, void * other, struct fd_hook_permsgdata *pmd, void * regdata), 
+                        void  *regdata, 
                         struct fd_hook_data_hdl *data_hdl,
                         struct fd_hook_hdl ** handler );

include/freeDiameter/libfdproto.h

@@ -2550 +2550 @@
 
 
+/* Helper for the hooks mechanism, for use from libfdcore */
+struct fd_msg_pmdl {
+        struct fd_list sentinel; /* if the sentinel.o field is NULL, the structure is not initialized. Otherwise it points to the cleanup function in libfdcore. */
+        pthread_mutex_t lock;
+};
+#define FD_MSG_PMDL_INITIALIZER(pmdl_ptr)        { FD_LIST_INITIALIZER(  (pmdl_ptr)->sentinel       ), PTHREAD_MUTEX_INITIALIZER }
+struct fd_msg_pmdl * fd_msg_pmdl_get(struct msg * msg);
+
 /***************************************/
 /*   Manage AVP values                 */

libfdcore/cnxctx.c

@@ -736 +736 @@
                 }
                 
+                // fd_msg_log(....)
+                
                 /* We have received a complete message, pass it to the daemon */
                 CHECK_FCT_DO( fd_event_send( fd_cnx_target_queue(conn), FDEVP_CNX_MSG_RECV, length, newmsg), /* continue or destroy everything? */);

libfdcore/core.c

@@ -187 +187 @@
         
         /* Initialize some modules */
+        CHECK_FCT( fd_hooks_init()  );
         CHECK_FCT( fd_queues_init() );
         CHECK_FCT( fd_msg_init()    );

libfdcore/fdcore-internal.h

@@ -363 +363 @@
 #define FD_CNX_ORDERED          (1 << 0)        /* All messages sent with this flag set will be delivered in the same order. No guarantee on other messages */
 
+/* Internal calls of the hook mechanism */
+void   fd_hook_call(enum fd_hook_type type, struct msg * msg, struct fd_peer * peer, void * other, struct fd_msg_pmdl * pmdl);
+void   fd_hook_associate(struct msg * msg, struct fd_msg_pmdl * pmdl);
+int    fd_hooks_init(void);
 #endif /* _FDCORE_INTERNAL_H */

libfdcore/hooks.c

@@ -36 +36 @@
 #include "fdcore-internal.h"
 
-struct fd_hook_hdl; 
-struct fd_hook_data_hdl;
-
+/* Structures for the fd_hook_data_hdl management */
+static struct fd_hook_data_hdl {
+        size_t  pmd_size;
+        void  (*pmd_init_cb)(struct fd_hook_permsgdata *);
+        void  (*pmd_fini_cb)(struct fd_hook_permsgdata *);
+} HDH_array[FD_HOOK_HANDLE_LIMIT];
+static int max_index = 0;
+static pthread_mutex_t HDH_lock = PTHREAD_MUTEX_INITIALIZER;
+
+/* The structure linked from the msg structure list */
+struct pmd_list_item {
+        struct fd_list  chain;          /* this list is ordered by hdl */
+        struct fd_hook_data_hdl * hdl; 
+        struct fd_hook_permsgdata { } pmd; /* this data belongs to the extension; we only know the size of it */
+};
+
+#define sizeof_pmd(hdl) (((size_t)&((struct pmd_list_item *)0)->pmd) + hdl->pmd_size)
+
+/* Now a hook registered by an extension */
+struct fd_hook_hdl {
+        struct fd_list chain[HOOK_PEER_LAST+1];
+        void (*fd_hook_cb)(enum fd_hook_type type, struct msg * msg, struct peer_hdr * peer, void * other, struct fd_hook_permsgdata *pmd, void * regdata);
+        void  *regdata;
+        struct fd_hook_data_hdl *data_hdl;
+};
+
+/* Array of those hooks */
+struct {
+        struct fd_list sentinel;
+        pthread_rwlock_t rwlock;
+} HS_array[HOOK_PEER_LAST+1];
+
+/* Initialize the array of sentinels for the hooks */
+int fd_hooks_init(void)
+{
+        int i;
+        for (i=0; i <= HOOK_PEER_LAST; i++) {
+                fd_list_init(&HS_array[i].sentinel, NULL);
+                CHECK_POSIX( pthread_rwlock_init(&HS_array[i].rwlock, NULL) );
+        }
+        return 0;
+}
+
+/* Get a slot in the array */
 int fd_hook_data_register(
-        struct fd_hook_permsgdata * (*permsgdata_new_cb)     (void),
-        void (*permsgdata_destroy_cb) (struct fd_hook_permsgdata *),
-        struct fd_hook_data_hdl **    new_handle
-)
-{
-        return ENOTSUP;
-}
-
-int fd_hook_register (  enum fd_hook_type type, 
-                        void (*fd_hook_cb)(enum fd_hook_type type, struct msg * msg, struct peer_hdr * peer, void * other, void * regdata), 
-                        void * regdata, 
+        size_t permsgdata_size,
+        void (*permsgdata_init_cb) (struct fd_hook_permsgdata *),
+        void (*permsgdata_fini_cb) (struct fd_hook_permsgdata *),
+        struct fd_hook_data_hdl **new_handle)
+{
+        int ret = ENOSPC, idx;
+        TRACE_ENTRY("%zd %p %p %p", permsgdata_size, permsgdata_init_cb, permsgdata_fini_cb, new_handle);
+        
+        CHECK_PARAMS( permsgdata_size && new_handle );
+        
+        CHECK_POSIX( pthread_mutex_lock(&HDH_lock) );
+        if (max_index < FD_HOOK_HANDLE_LIMIT) {
+                idx = max_index++;
+                ret = 0;
+        }
+        CHECK_POSIX( pthread_mutex_unlock(&HDH_lock) );
+        
+        if (ret == 0) {
+                HDH_array[idx].pmd_size = permsgdata_size;
+                HDH_array[idx].pmd_init_cb = permsgdata_init_cb;
+                HDH_array[idx].pmd_fini_cb = permsgdata_fini_cb;
+                *new_handle = &HDH_array[idx];
+        }
+        
+        return ret;
+}
+
+/* Register a new hook callback */
+int fd_hook_register (  uint32_t type_mask, 
+                        void (*fd_hook_cb)(enum fd_hook_type type, struct msg * msg, struct peer_hdr * peer, void * other, struct fd_hook_permsgdata *pmd, void * regdata), 
+                        void  *regdata, 
                         struct fd_hook_data_hdl *data_hdl,
                         struct fd_hook_hdl ** handler )
 {
-        return ENOTSUP;
-}
-
-
+        struct fd_hook_hdl * newhdl = NULL;
+        int i;
+        
+        TRACE_ENTRY("%x %p %p %p %p", type_mask, fd_hook_cb, regdata, data_hdl, handler);
+        
+        CHECK_PARAMS( fd_hook_cb && handler );
+        
+        CHECK_MALLOC( newhdl = malloc(sizeof(struct fd_hook_hdl)) );
+        memset(newhdl, 0, sizeof(struct fd_hook_hdl));
+        
+        newhdl->fd_hook_cb = fd_hook_cb;
+        newhdl->regdata = regdata;
+        newhdl->data_hdl = data_hdl;
+        
+        for (i=0; i <= HOOK_PEER_LAST; i++) {
+                fd_list_init(&newhdl->chain[i], newhdl);
+                if (type_mask & (1<<i)) {
+                        CHECK_POSIX( pthread_rwlock_wrlock(&HS_array[i].rwlock) );
+                        fd_list_insert_before( &HS_array[i].sentinel, &newhdl->chain[i]);
+                        CHECK_POSIX( pthread_rwlock_unlock(&HS_array[i].rwlock) );
+                }
+        }
+        
+        *handler = newhdl;
+        return 0;
+}
+
+/* free this hook callback */
 int fd_hook_unregister( struct fd_hook_hdl * handler )
 {
-        return ENOTSUP;
-}
-
+        int i;
+        TRACE_ENTRY("%p", handler);
+        CHECK_PARAMS( handler );
+        
+        for (i=0; i <= HOOK_PEER_LAST; i++) {
+                if ( ! FD_IS_LIST_EMPTY(&handler->chain[i])) {
+                        CHECK_POSIX( pthread_rwlock_wrlock(&HS_array[i].rwlock) );
+                        fd_list_unlink(&handler->chain[i]);
+                        CHECK_POSIX( pthread_rwlock_unlock(&HS_array[i].rwlock) );
+                }
+        }
+        
+        free(handler);
+        
+        return 0;
+}
+
+/* callback for the libfdproto to free the data associated with a message */
+static void pmdl_free(struct fd_msg_pmdl *pmdl)
+{
+        /* destroy all the items in the list */
+        while (!FD_IS_LIST_EMPTY(&pmdl->sentinel)) {
+                struct pmd_list_item * li = (struct pmd_list_item *)(pmdl->sentinel.next);
+                if (li->hdl->pmd_fini_cb) {
+                        (*li->hdl->pmd_fini_cb)(&li->pmd);
+                }
+                fd_list_unlink(&li->chain);
+                free(li);
+        }
+        CHECK_POSIX_DO( pthread_mutex_destroy(&pmdl->lock), );
+        pmdl->sentinel.o = NULL;
+}
+
+/* Save the list of pmd into the message structure, as well as the callback to free this list */
+void   fd_hook_associate(struct msg * msg, struct fd_msg_pmdl * pmdl)
+{
+        struct fd_msg_pmdl * in_msg;
+        
+        CHECK_PARAMS_DO( msg && pmdl, return );
+        in_msg = fd_msg_pmdl_get(msg);
+        ASSERT(in_msg && (in_msg->sentinel.o == NULL)); /* error / already initialized ??? */
+        fd_list_init(&in_msg->sentinel, pmdl_free);
+        CHECK_POSIX_DO( pthread_mutex_init(&in_msg->lock, NULL), );
+        /* Now move all items from the pmdl pointer into the initialized list */
+        CHECK_POSIX_DO( pthread_mutex_lock(&pmdl->lock), );
+        fd_list_move_end(&in_msg->sentinel, &pmdl->sentinel);
+        CHECK_POSIX_DO( pthread_mutex_unlock(&pmdl->lock), );
+        pmdl_free(pmdl);
+        /* We're done */
+}
+
+/* Return the location of the permsgdata area corresponding to this handle, after eventually having created it. Return NULL in case of failure */
+static struct fd_hook_permsgdata * get_or_create_pmd(struct fd_msg_pmdl *pmdl, struct fd_hook_hdl * h) 
+{
+        struct fd_hook_permsgdata * ret = NULL;
+        struct fd_list * li;
+        CHECK_POSIX_DO( pthread_mutex_lock(&pmdl->lock), );
+        
+        /* Search in the list for an item with the same handle. The list is ordered by this handle */
+        for (li=pmdl->sentinel.next; li != &pmdl->sentinel; li = li->next) {
+                struct pmd_list_item * pli = (struct pmd_list_item *) li;
+                if (pli->hdl == h->data_hdl)
+                        ret = &pli->pmd;
+                if (pli->hdl >= h->data_hdl)
+                        break;
+        }
+        if (!ret) {
+                /* we need to create a new one and insert before li */
+                struct pmd_list_item * pli;
+                CHECK_MALLOC_DO( pli = malloc(sizeof_pmd(h->data_hdl)), );
+                if (pli) {
+                        memset(pli, 0, sizeof_pmd(h->data_hdl));
+                        fd_list_init(&pli->chain, pli);
+                        pli->hdl = h->data_hdl;
+                        ret = &pli->pmd;
+                        if (h->data_hdl->pmd_init_cb) {
+                                (*h->data_hdl->pmd_init_cb)(ret);
+                        }
+                        fd_list_insert_before(li, &pli->chain);
+                }
+        }
+        
+        CHECK_POSIX_DO( pthread_mutex_unlock(&pmdl->lock), );
+        return ret;
+}
+
+
+/* The function that does the work of calling the extension's callbacks and also managing the permessagedata structures */
+void   fd_hook_call(enum fd_hook_type type, struct msg * msg, struct fd_peer * peer, void * other, struct fd_msg_pmdl * pmdl)
+{
+        struct fd_list * li;
+        ASSERT(type <= HOOK_PEER_LAST);
+        
+        /* lock the list of hooks for this type */
+        CHECK_POSIX_DO( pthread_rwlock_rdlock(&HS_array[type].rwlock), );
+        
+        /* for each registered hook */
+        for (li = HS_array[type].sentinel.next; li != &HS_array[type].sentinel; li = li->next) {
+                struct fd_hook_hdl * h = (struct fd_hook_hdl *)li->o;
+                struct fd_hook_permsgdata * pmd = NULL;
+                
+                /* do we need to handle pmd ? */
+                if (h->data_hdl && pmdl) {
+                        pmd = get_or_create_pmd(pmdl, h);
+                }
+                
+                /* Now, call this callback */
+                (*h->fd_hook_cb)(type, msg, &peer->p_hdr, other, pmd, h->regdata);
+        }
+        
+        /* done */
+        CHECK_POSIX_DO( pthread_rwlock_unlock(&HS_array[type].rwlock), );
+}

libfdproto/messages.c

@@ -137 +137 @@
         DiamId_t                 msg_src_id;            /* Diameter Id of the peer this message was received from. This string is malloc'd and must be freed */
         size_t                   msg_src_id_len;        /* cached length of this string */
-        
+        struct fd_msg_pmdl       msg_pmdl;              /* list of permessagedata structures. */
 };
 
@@ -674 +674 @@
         }
         
+        if ((obj->type == MSG_MSG) && (_M(obj)->msg_pmdl.sentinel.o != NULL)) {
+                ((void (*)(struct fd_msg_pmdl *))_M(obj)->msg_pmdl.sentinel.o)(&_M(obj)->msg_pmdl);
+        }
+        
         /* free the object */
         free(obj);
@@ -1496 +1500 @@
         
         return 0;
+}
+
+/* Retrieve the location of the pmd list for the message; return NULL if failed */
+struct fd_msg_pmdl * fd_msg_pmdl_get(struct msg * msg)
+{
+        CHECK_PARAMS_DO( CHECK_MSG(msg), return NULL );
+        return &msg->msg_pmdl;
 }