lib: Add fccntl operation to get queue lengths

This adds the FLOWGRXQLEN and FLOWGTXQLEN operations to fccntl to get
the number of packets that are in the receive and transmit buffers
respectively. The flow statistics are updated to show these queue
lengths.

Signed-off-by: Dimitri Staessens <[email protected]>
Signed-off-by: Sander Vrijders <[email protected]>

2 files changed, 26 insertions, 5 deletions

diff --git a/src/ipcpd/normal/dt.c b/src/ipcpd/normal/dt.c
index 566ede24..68cd498f 100644
--- a/src/ipcpd/normal/dt.c
+++ b/src/ipcpd/normal/dt.c
@@ -35,6 +35,9 @@
 #include <ouroboros/dev.h>
 #include <ouroboros/notifier.h>
 #include <ouroboros/rib.h>
+#ifdef IPCP_FLOW_STATS
+#include <ouroboros/fccntl.h>
+#endif
 
 #include "connmgr.h"
 #include "ipcp.h"
@@ -53,7 +56,7 @@
 #include <inttypes.h>
 #include <assert.h>
 
-#define STAT_FILE_LEN 2088
+#define STAT_FILE_LEN 2205
 
 #ifndef CLOCK_REALTIME_COARSE
 #define CLOCK_REALTIME_COARSE CLOCK_REALTIME
@@ -110,6 +113,8 @@ static int dt_stat_read(const char * path,
         char        str[681];
         char        addrstr[20];
         char        tmstr[20];
+        size_t      rxqlen = 0;
+        size_t      txqlen = 0;
         struct tm * tm;
 
         /* NOTE: we may need stronger checks. */
@@ -135,10 +140,17 @@ static int dt_stat_read(const char * path,
         tm = localtime(&dt.stat[fd].stamp);
         strftime(tmstr, sizeof(tmstr), "%F %T", tm);
 
+        if (fd >= PROG_RES_FDS) {
+                fccntl(fd, FLOWGRXQLEN, &rxqlen);
+                fccntl(fd, FLOWGTXQLEN, &txqlen);
+        }
+
         sprintf(buf,
-                "Established  : %20s\n"
-                "Endpt address: %20s\n",
-                tmstr, addrstr);
+                "Flow established at:      %20s\n"
+                "Endpoint address:         %20s\n"
+                "Queued packets (rx):      %20zu\n"
+                "Queued packets (tx):      %20zu\n\n",
+                tmstr, addrstr, rxqlen, txqlen);
 
         for (i = 0; i < QOS_CUBE_MAX; ++i) {
                 sprintf(str,
@@ -430,7 +442,7 @@ static void sdu_handler(int                  fd,
 #endif
         } else {
                 dt_pci_shrink(sdb);
-                if (dt_pci.eid > PROG_RES_FDS) {
+                if (dt_pci.eid >= PROG_RES_FDS) {
                         if (ipcp_flow_write(dt_pci.eid, sdb)) {
                                 ipcp_sdb_release(sdb);
 #ifdef IPCP_FLOW_STATS
diff --git a/src/lib/dev.c b/src/lib/dev.c
index 99ab4359..7e829a5f 100644
--- a/src/lib/dev.c
+++ b/src/lib/dev.c
@@ -670,6 +670,7 @@ int fccntl(int fd,
         qosspec_t *       qs;
         uint32_t          rx_acl;
         uint32_t          tx_acl;
+        size_t *          qlen;
         struct flow *     flow;
 
         if (fd < 0 || fd >= PROG_MAX_FLOWS)
@@ -728,6 +729,14 @@ int fccntl(int fd,
                         goto einval;
                 *qs = flow->spec;
                 break;
+        case FLOWGRXQLEN:
+                qlen  = va_arg(l, size_t *);
+                *qlen = shm_rbuff_queued(flow->rx_rb);
+                break;
+        case FLOWGTXQLEN:
+                qlen  = va_arg(l, size_t *);
+                *qlen = shm_rbuff_queued(flow->rx_rb);
+                break;
         case FLOWSFLAGS:
                 flow->oflags = va_arg(l, uint32_t);
                 rx_acl = shm_rbuff_get_acl(flow->rx_rb);