session: encapsulate statistics counters

Group the core session starting, active, and finishing statistics behind the private ap_session_stat storage in session.c instead of exposing writable counters through ap_session.h. This keeps ownership inside the session core while preserving the existing CLI and ACCEL-PPP-MIB counter semantics.

Route session counter updates through ap_session_stat_*() helpers. Session start, activation, termination, finish, and shutdown-idle paths no longer open-code individual counter increments/decrements; the update policy now lives beside the session-owned storage and uses relaxed atomic operations for the simple state counters.

Make the CLI show-stat path render from a local snapshot and convert the PPP SNMP starting/active/finishing scalars from watched raw pointers to scalar handlers. PPP controllers now read max-session limits through ap_session_stat_starting() and ap_session_stat_active(), removing external direct access to ap_session_stat.

Signed-off-by: Denys Fedoryshchenko <denys.f@collabora.com>

1 files changed, 98 insertions, 47 deletions

diff --git a/accel-pppd/extra/net-snmp/statPPP.c b/accel-pppd/extra/net-snmp/statPPP.c
index 37e4630c..7dc1f659 100644
--- a/accel-pppd/extra/net-snmp/statPPP.c
+++ b/accel-pppd/extra/net-snmp/statPPP.c
@@ -6,9 +6,22 @@
 #include <net-snmp/net-snmp-config.h>
 #include <net-snmp/net-snmp-includes.h>
 #include <net-snmp/agent/net-snmp-agent-includes.h>
+
+#include "ap_session.h"
 #include "statPPP.h"
 
-#include "ppp.h"
+static int handle_statPPPStarting(netsnmp_mib_handler *handler,
+				  netsnmp_handler_registration *reginfo,
+				  netsnmp_agent_request_info *reqinfo,
+				  netsnmp_request_info *requests);
+static int handle_statPPPActive(netsnmp_mib_handler *handler,
+				netsnmp_handler_registration *reginfo,
+				netsnmp_agent_request_info *reqinfo,
+				netsnmp_request_info *requests);
+static int handle_statPPPFinishing(netsnmp_mib_handler *handler,
+				   netsnmp_handler_registration *reginfo,
+				   netsnmp_agent_request_info *reqinfo,
+				   netsnmp_request_info *requests);
 
 /*
  * Our initialization routine, called automatically by the agent
@@ -17,77 +30,115 @@
 void
 init_statPPP(void)
 {
-  netsnmp_handler_registration *reg;
-  netsnmp_watcher_info         *winfo;
-
     static oid statPPPStarting_oid[] = { 1,3,6,1,4,1,8072,100,1,2,1 };
     static oid statPPPActive_oid[] = { 1,3,6,1,4,1,8072,100,1,2,2 };
     static oid statPPPFinishing_oid[] = { 1,3,6,1,4,1,8072,100,1,2,3 };
 
-  /*
-   * a debugging statement.  Run the agent with -DstatPPP to see
-   * the output of this debugging statement.
-   */
   DEBUGMSGTL(("statPPP", "Initializing the statPPP module\n"));
 
-
-    /*
-     * Register scalar watchers for each of the MIB objects.
-     * The ASN type and RO/RW status are taken from the MIB definition,
-     * but can be adjusted if needed.
-     *
-     * In most circumstances, the scalar watcher will handle all
-     * of the necessary processing.  But the NULL parameter in the
-     * netsnmp_create_handler_registration() call can be used to
-     * supply a user-provided handler if necessary.
-     *
-     * This approach can also be used to handle Counter64, string-
-     * and OID-based watched scalars (although variable-sized writeable
-     * objects will need some more specialised initialisation).
-     */
     DEBUGMSGTL(("statPPP",
                 "Initializing statPPPStarting scalar integer.  Default value = %d\n",
                 0));
-    reg = netsnmp_create_handler_registration(
-             "statPPPStarting", NULL,
+    if (netsnmp_register_scalar(netsnmp_create_handler_registration(
+             "statPPPStarting", handle_statPPPStarting,
               statPPPStarting_oid, OID_LENGTH(statPPPStarting_oid),
-              HANDLER_CAN_RONLY);
-    winfo = netsnmp_create_watcher_info(
-                &ap_session_stat.starting, sizeof(ap_session_stat.starting),
-                 ASN_INTEGER, WATCHER_FIXED_SIZE);
-    if (netsnmp_register_watched_scalar( reg, winfo ) < 0 ) {
-        snmp_log( LOG_ERR, "Failed to register watched statPPPStarting" );
+              HANDLER_CAN_RONLY)) < 0 ) {
+        snmp_log( LOG_ERR, "Failed to register statPPPStarting" );
     }
 
     DEBUGMSGTL(("statPPP",
                 "Initializing statPPPActive scalar integer.  Default value = %d\n",
                 0));
-    reg = netsnmp_create_handler_registration(
-             "statPPPActive", NULL,
+    if (netsnmp_register_scalar(netsnmp_create_handler_registration(
+             "statPPPActive", handle_statPPPActive,
               statPPPActive_oid, OID_LENGTH(statPPPActive_oid),
-              HANDLER_CAN_RONLY);
-    winfo = netsnmp_create_watcher_info(
-                &ap_session_stat.active, sizeof(ap_session_stat.active),
-                 ASN_INTEGER, WATCHER_FIXED_SIZE);
-    if (netsnmp_register_watched_scalar( reg, winfo ) < 0 ) {
-        snmp_log( LOG_ERR, "Failed to register watched statPPPActive" );
+              HANDLER_CAN_RONLY)) < 0 ) {
+        snmp_log( LOG_ERR, "Failed to register statPPPActive" );
     }
 
     DEBUGMSGTL(("statPPP",
                 "Initializing statPPPFinishing scalar integer.  Default value = %d\n",
                 0));
-    reg = netsnmp_create_handler_registration(
-             "statPPPFinishing", NULL,
+    if (netsnmp_register_scalar(netsnmp_create_handler_registration(
+             "statPPPFinishing", handle_statPPPFinishing,
               statPPPFinishing_oid, OID_LENGTH(statPPPFinishing_oid),
-              HANDLER_CAN_RONLY);
-    winfo = netsnmp_create_watcher_info(
-                &ap_session_stat.finishing, sizeof(ap_session_stat.finishing),
-                 ASN_INTEGER, WATCHER_FIXED_SIZE);
-    if (netsnmp_register_watched_scalar( reg, winfo ) < 0 ) {
-        snmp_log( LOG_ERR, "Failed to register watched statPPPFinishing" );
+              HANDLER_CAN_RONLY)) < 0 ) {
+        snmp_log( LOG_ERR, "Failed to register statPPPFinishing" );
     }
 
 
   DEBUGMSGTL(("statPPP",
               "Done initalizing statPPP module\n"));
 }
+
+static int handle_statPPPStarting(netsnmp_mib_handler *handler,
+				  netsnmp_handler_registration *reginfo,
+				  netsnmp_agent_request_info *reqinfo,
+				  netsnmp_request_info *requests)
+{
+	long stat;
+
+	(void)handler;
+	(void)reginfo;
+
+	switch (reqinfo->mode) {
+	case MODE_GET:
+		stat = ap_session_stat_starting();
+		snmp_set_var_typed_value(requests->requestvb, ASN_INTEGER,
+					 (u_char *)&stat, sizeof(stat));
+		break;
+	default:
+		snmp_log(LOG_ERR, "unknown mode (%d) in handle_statPPPStarting\n", reqinfo->mode);
+		return SNMP_ERR_GENERR;
+	}
+
+	return SNMP_ERR_NOERROR;
+}
+
+static int handle_statPPPActive(netsnmp_mib_handler *handler,
+				netsnmp_handler_registration *reginfo,
+				netsnmp_agent_request_info *reqinfo,
+				netsnmp_request_info *requests)
+{
+	long stat;
+
+	(void)handler;
+	(void)reginfo;
+
+	switch (reqinfo->mode) {
+	case MODE_GET:
+		stat = ap_session_stat_active();
+		snmp_set_var_typed_value(requests->requestvb, ASN_INTEGER,
+					 (u_char *)&stat, sizeof(stat));
+		break;
+	default:
+		snmp_log(LOG_ERR, "unknown mode (%d) in handle_statPPPActive\n", reqinfo->mode);
+		return SNMP_ERR_GENERR;
+	}
+
+	return SNMP_ERR_NOERROR;
+}
+
+static int handle_statPPPFinishing(netsnmp_mib_handler *handler,
+				   netsnmp_handler_registration *reginfo,
+				   netsnmp_agent_request_info *reqinfo,
+				   netsnmp_request_info *requests)
+{
+	long stat;
+
+	(void)handler;
+	(void)reginfo;
+
+	switch (reqinfo->mode) {
+	case MODE_GET:
+		stat = ap_session_stat_finishing();
+		snmp_set_var_typed_value(requests->requestvb, ASN_INTEGER,
+					 (u_char *)&stat, sizeof(stat));
+		break;
+	default:
+		snmp_log(LOG_ERR, "unknown mode (%d) in handle_statPPPFinishing\n", reqinfo->mode);
+		return SNMP_ERR_GENERR;
+	}
+
+	return SNMP_ERR_NOERROR;
+}