gnrc_ipv6_ext_frag: initial import of statistics module

makefiles/pseudomodules.inc.mk

@@ -18,6 +18,7 @@ PSEUDOMODULES += event_%
 PSEUDOMODULES += fmt_%
 PSEUDOMODULES += gnrc_dhcpv6_%
 PSEUDOMODULES += gnrc_ipv6_default
+PSEUDOMODULES += gnrc_ipv6_ext_frag_stats
 PSEUDOMODULES += gnrc_ipv6_router
 PSEUDOMODULES += gnrc_ipv6_router_default
 PSEUDOMODULES += gnrc_ipv6_nib_6lbr

sys/include/net/gnrc/ipv6/ext/frag.h

@@ -93,6 +93,18 @@ typedef struct {
     uint8_t last;           /**< received last fragment */
 } gnrc_ipv6_ext_frag_rbuf_t;
 
+/**
+ * @brief   Statistics on reassembly and reassembly
+ */
+typedef struct {
+    unsigned rbuf_full;     /**< counts the number of events where the
+                             *   reassembly buffer is full */
+    unsigned frag_full;     /**< counts the number of events that there where
+                             *   no @ref gnrc_sixlowpan_frag_fb_t available */
+    unsigned datagrams;     /**< reassembled datagrams */
+    unsigned fragments;     /**< total fragments of reassembled fragments */
+} gnrc_ipv6_ext_frag_stats_t;
+
 /**
  * @brief   Initializes IPv6 fragmentation and reassembly
  * @internal
@@ -187,6 +199,14 @@ static inline void gnrc_ipv6_ext_frag_rbuf_del(gnrc_ipv6_ext_frag_rbuf_t *rbuf)
 void gnrc_ipv6_ext_frag_rbuf_gc(void);
 /** @} */
 
+/**
+ * @brief   Get the current statistics on reassembly and fragmentation
+ *
+ * @return  The current statistics on reassembly and fragmentation.
+ * @return  NULL, if module `gnrc_ipv6_ext_frag_stats` is not compiled in.
+ */
+gnrc_ipv6_ext_frag_stats_t *gnrc_ipv6_ext_frag_stats(void);
+
 #ifdef __cplusplus
 }
 #endif

sys/net/gnrc/network_layer/ipv6/ext/frag/gnrc_ipv6_ext_frag.c

@@ -40,6 +40,7 @@ static gnrc_ipv6_ext_frag_limits_t _limits_pool[CONFIG_GNRC_IPV6_EXT_FRAG_LIMITS
 static clist_node_t _free_limits;
 static xtimer_t _gc_xtimer;
 static msg_t _gc_msg = { .type = GNRC_IPV6_EXT_FRAG_RBUF_GC };
+static gnrc_ipv6_ext_frag_stats_t _stats;
 
 /**
  * @todo    Implement better mechanism as described in
@@ -278,6 +279,9 @@ static gnrc_ipv6_ext_frag_send_t *_snd_buf_alloc(void)
             return snd_buf;
         }
     }
+    if (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS)) {
+        _stats.frag_full++;
+    }
     return NULL;
 }
 
@@ -495,6 +499,10 @@ gnrc_pktsnip_t *gnrc_ipv6_ext_frag_reass(gnrc_pktsnip_t *pkt)
         gnrc_ipv6_ext_frag_rbuf_del(rbuf);
         ipv6->len = byteorder_htons(byteorder_ntohs(ipv6->len) -
                                     sizeof(ipv6_ext_frag_t));
+        if (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS)) {
+            _stats.fragments++;
+            _stats.datagrams++;
+        }
         return pkt;
     }
     else {
@@ -562,10 +570,16 @@ gnrc_ipv6_ext_frag_rbuf_t *gnrc_ipv6_ext_frag_rbuf_get(ipv6_hdr_t *ipv6,
         assert(oldest != NULL); /* reassembly buffer is full, so there needs
                                  * to be an oldest entry */
         DEBUG("ipv6_ext_frag: dropping oldest entry\n");
+        if (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS)) {
+            _stats.rbuf_full++;
+        }
         gnrc_ipv6_ext_frag_rbuf_del(oldest);
         res = oldest;
         _init_rbuf(res, ipv6, id);
     }
+    else if (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS) && (res == NULL)) {
+        _stats.rbuf_full++;
+    }
     return res;
 }
 
@@ -589,6 +603,11 @@ void gnrc_ipv6_ext_frag_rbuf_gc(void)
     }
 }
 
+gnrc_ipv6_ext_frag_stats_t *gnrc_ipv6_ext_frag_stats(void)
+{
+    return (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS)) ? &_stats : NULL;
+}
+
 typedef struct {
     uint16_t start;
     uint16_t end;
@@ -698,6 +717,10 @@ static gnrc_pktsnip_t *_completed(gnrc_ipv6_ext_frag_rbuf_t *rbuf)
         /* rewrite length */
         rbuf->ipv6->len = byteorder_htons(rbuf->pkt_len);
         rbuf->pkt = NULL;
+        if (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS)) {
+            _stats.fragments += clist_count(&rbuf->limits);
+            _stats.datagrams++;
+        }
         gnrc_ipv6_ext_frag_rbuf_free(rbuf);
         return res;
     }

sys/shell/commands/Makefile

@@ -32,6 +32,9 @@ endif
 ifneq (,$(filter fib,$(USEMODULE)))
   SRC += sc_fib.c
 endif
+ifneq (,$(filter gnrc_ipv6_ext_frag_stats,$(USEMODULE)))
+  SRC += sc_gnrc_ipv6_frag_stats.c
+endif
 ifneq (,$(filter gnrc_ipv6_nib,$(USEMODULE)))
   SRC += sc_gnrc_ipv6_nib.c
 endif

sys/shell/commands/sc_gnrc_ipv6_frag_stats.c

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2020 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @{
+ *
+ * @file
+ * @author  Martine Lenders <m.lenders@fu-berlin.de>
+ */
+
+#include <stdio.h>
+#include "net/gnrc/ipv6/ext/frag.h"
+
+int _gnrc_ipv6_frag_stats(int argc, char **argv)
+{
+    (void)argc;
+    (void)argv;
+    if (IS_USED(MODULE_GNRC_IPV6_EXT_FRAG_STATS)) {
+        gnrc_ipv6_ext_frag_stats_t *stats = gnrc_ipv6_ext_frag_stats();
+
+        printf("rbuf full: %u\n", stats->rbuf_full);
+        printf("frag full: %u\n", stats->frag_full);
+        printf("frags complete: %u\n", stats->fragments);
+        printf("dgs complete: %u\n", stats->datagrams);
+    }
+    return 0;
+}
+
+
+/** @} */

sys/shell/commands/shell_commands.c

@@ -90,6 +90,10 @@ extern int _gnrc_netif_send(int argc, char **argv);
 extern int _fib_route_handler(int argc, char **argv);
 #endif
 
+#ifdef MODULE_GNRC_IPV6_EXT_FRAG_STATS
+extern int _gnrc_ipv6_frag_stats(int argc, char **argv);
+#endif
+
 #ifdef MODULE_GNRC_IPV6_WHITELIST
 extern int _whitelist(int argc, char **argv);
 #endif
@@ -214,6 +218,9 @@ const shell_command_t _shell_command_list[] = {
 #ifdef MODULE_FIB
     {"fibroute", "Manipulate the FIB (info: 'fibroute [add|del]')", _fib_route_handler},
 #endif
+#ifdef MODULE_GNRC_IPV6_EXT_FRAG_STATS
+    {"ip6_frag", "IPv6 fragmentation statistics", _gnrc_ipv6_frag_stats },
+#endif
 #ifdef MODULE_GNRC_IPV6_WHITELIST
     {"whitelist", "whitelists an address for receival ('whitelist [add|del|help]')", _whitelist },
 #endif