Merged in dstaesse/ouroboros/be-select (pull request #184)

select() like call

11 files changed, 730 insertions, 73 deletions

diff --git a/include/ouroboros/dev.h b/include/ouroboros/dev.h
index eb779953..91d5c7de 100644
--- a/include/ouroboros/dev.h
+++ b/include/ouroboros/dev.h
@@ -22,6 +22,7 @@
 
 #include <unistd.h>
 #include <stdint.h>
+#include <sys/time.h>
 
 #include <ouroboros/qos.h>
 #include <ouroboros/flow.h>
@@ -53,5 +54,6 @@ int     flow_dealloc(int fd);
 int     flow_cntl(int fd, int cmd, int oflags);
 ssize_t flow_write(int fd, void * buf, size_t count);
 ssize_t flow_read(int fd, void * buf, size_t count);
+int     flow_select(const struct timespec * timeout);
 
 #endif
diff --git a/include/ouroboros/shm_ap_rbuff.h b/include/ouroboros/shm_ap_rbuff.h
index 78926869..257a289d 100644
--- a/include/ouroboros/shm_ap_rbuff.h
+++ b/include/ouroboros/shm_ap_rbuff.h
@@ -25,6 +25,7 @@
 #define OUROBOROS_SHM_AP_RBUFF_H
 
 #include <sys/types.h>
+#include <sys/time.h>
 #include <stdbool.h>
 
 struct shm_ap_rbuff;
@@ -41,6 +42,8 @@ void                  shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb);
 int                   shm_ap_rbuff_write(struct shm_ap_rbuff * rb,
                                          struct rb_entry * e);
 struct rb_entry *     shm_ap_rbuff_read(struct shm_ap_rbuff * rb);
+int                   shm_ap_rbuff_peek(struct shm_ap_rbuff * rb,
+                                        const struct timespec * timeout);
 ssize_t               shm_ap_rbuff_read_port(struct shm_ap_rbuff * rb,
                                              int port_id);
 pid_t                 shm_ap_rbuff_get_api(struct shm_ap_rbuff * rb);
diff --git a/include/ouroboros/shm_du_map.h b/include/ouroboros/shm_du_map.h
index 11fe35c6..b9c56cf8 100644
--- a/include/ouroboros/shm_du_map.h
+++ b/include/ouroboros/shm_du_map.h
@@ -39,13 +39,12 @@ void                shm_du_map_destroy(struct shm_du_map * dum);
 void *              shm_du_map_sanitize(void * o);
 
 /* returns the index of the buffer in the DU map */
-ssize_t  shm_du_map_write(struct shm_du_map * dum,
-                          pid_t               dst_api,
-                          size_t              headspace,
-                          size_t              tailspace,
-                          uint8_t *           data,
-                          size_t              data_len);
-
+ssize_t   shm_du_map_write(struct shm_du_map * dum,
+                           pid_t               dst_api,
+                           size_t              headspace,
+                           size_t              tailspace,
+                           uint8_t *           data,
+                           size_t              data_len);
 int       shm_du_map_read(uint8_t **          dst,
                           struct shm_du_map * dum,
                           ssize_t             idx);
diff --git a/src/lib/dev.c b/src/lib/dev.c
index f13c8423..22e77169 100644
--- a/src/lib/dev.c
+++ b/src/lib/dev.c
@@ -130,17 +130,14 @@ void ap_fini(void)
         free(_ap_instance);
 }
 
-#if 0
 static int port_id_to_fd(int port_id)
 {
         int i;
         for (i = 0; i < AP_MAX_FLOWS; ++i)
-                if (_ap_instance->flows[i].port_id == port_id
-                        && _ap_instance->flows[i].state != FLOW_NULL)
+                if (_ap_instance->flows[i].port_id == port_id)
                         return i;
         return -1;
 }
-#endif
 
 int flow_accept(char ** ae_name)
 {
@@ -523,6 +520,14 @@ ssize_t flow_write(int fd, void * buf, size_t count)
         return 0;
 }
 
+int flow_select(const struct timespec * timeout)
+{
+        int port_id = shm_ap_rbuff_peek(_ap_instance->rb, timeout);
+        if (port_id < 0)
+                return port_id;
+        return port_id_to_fd(port_id);
+}
+
 ssize_t flow_read(int fd, void * buf, size_t count)
 {
         int idx = -1;
diff --git a/src/lib/shm_ap_rbuff.c b/src/lib/shm_ap_rbuff.c
index 84f7617a..be4cd0c2 100644
--- a/src/lib/shm_ap_rbuff.c
+++ b/src/lib/shm_ap_rbuff.c
@@ -28,6 +28,7 @@
 #include <ouroboros/logs.h>
 #include <ouroboros/shm_ap_rbuff.h>
 #include <ouroboros/lockfile.h>
+#include <ouroboros/time_utils.h>
 
 #include <pthread.h>
 #include <sys/mman.h>
@@ -39,6 +40,8 @@
 #include <signal.h>
 #include <sys/stat.h>
 
+#define PTHREAD_COND_CLOCK CLOCK_MONOTONIC
+
 #define SHM_RBUFF_FILE_SIZE (SHM_RBUFF_SIZE * sizeof(struct rb_entry)          \
                              + 2 * sizeof(size_t) + sizeof(pthread_mutex_t)    \
                              + sizeof (pthread_cond_t))
@@ -54,7 +57,7 @@ struct shm_ap_rbuff {
         struct rb_entry * shm_base;    /* start of entry */
         size_t *          ptr_head;    /* start of ringbuffer head */
         size_t *          ptr_tail;    /* start of ringbuffer tail */
-        pthread_mutex_t * shm_mutex;   /* lock all free space in shm */
+        pthread_mutex_t * lock;        /* lock all free space in shm */
         pthread_cond_t *  work;        /* threads will wait for a signal */
         pid_t             api;         /* api to which this rb belongs */
         int               fd;
@@ -73,31 +76,31 @@ struct shm_ap_rbuff * shm_ap_rbuff_create()
 
         rb = malloc(sizeof(*rb));
         if (rb == NULL) {
-                LOG_DBGF("Could not allocate struct.");
+                LOG_DBG("Could not allocate struct.");
                 return NULL;
         }
 
         shm_fd = shm_open(fn, O_CREAT | O_EXCL | O_RDWR, 0666);
         if (shm_fd == -1) {
-                LOG_DBGF("Failed creating ring buffer.");
+                LOG_DBG("Failed creating ring buffer.");
                 free(rb);
                 return NULL;
         }
 
         if (fchmod(shm_fd, 0666)) {
-                LOG_DBGF("Failed to chmod shared memory.");
+                LOG_DBG("Failed to chmod shared memory.");
                 free(rb);
                 return NULL;
         }
 
         if (ftruncate(shm_fd, SHM_RBUFF_FILE_SIZE - 1) < 0) {
-                LOG_DBGF("Failed to extend ringbuffer.");
+                LOG_DBG("Failed to extend ringbuffer.");
                 free(rb);
                 return NULL;
         }
 
         if (write(shm_fd, "", 1) != 1) {
-                LOG_DBGF("Failed to finalise extension of ringbuffer.");
+                LOG_DBG("Failed to finalise extension of ringbuffer.");
                 free(rb);
                 return NULL;
         }
@@ -110,30 +113,31 @@ struct shm_ap_rbuff * shm_ap_rbuff_create()
                         0);
 
         if (shm_base == MAP_FAILED) {
-                LOG_DBGF("Failed to map shared memory.");
+                LOG_DBG("Failed to map shared memory.");
                 if (close(shm_fd) == -1)
-                        LOG_DBGF("Failed to close invalid shm.");
+                        LOG_DBG("Failed to close invalid shm.");
 
                 if (shm_unlink(fn) == -1)
-                        LOG_DBGF("Failed to remove invalid shm.");
+                        LOG_DBG("Failed to remove invalid shm.");
 
                 free(rb);
                 return NULL;
         }
 
-        rb->shm_base  = shm_base;
-        rb->ptr_head  = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE);
-        rb->ptr_tail  = rb->ptr_head + 1;
-        rb->shm_mutex = (pthread_mutex_t *) (rb->ptr_tail + 1);
-        rb->work      = (pthread_cond_t *) (rb->shm_mutex + 1);
+        rb->shm_base = shm_base;
+        rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE);
+        rb->ptr_tail = rb->ptr_head + 1;
+        rb->lock     = (pthread_mutex_t *) (rb->ptr_tail + 1);
+        rb->work     = (pthread_cond_t *) (rb->lock + 1);
 
         pthread_mutexattr_init(&mattr);
         pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
         pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
-        pthread_mutex_init(rb->shm_mutex, &mattr);
+        pthread_mutex_init(rb->lock, &mattr);
 
         pthread_condattr_init(&cattr);
         pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
+        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
         pthread_cond_init(rb->work, &cattr);
 
         *rb->ptr_head = 0;
@@ -156,13 +160,13 @@ struct shm_ap_rbuff * shm_ap_rbuff_open(pid_t api)
 
         rb = malloc(sizeof(*rb));
         if (rb == NULL) {
-                LOG_DBGF("Could not allocate struct.");
+                LOG_DBG("Could not allocate struct.");
                 return NULL;
         }
 
         shm_fd = shm_open(fn, O_RDWR, 0666);
         if (shm_fd == -1) {
-                LOG_DBGF("%d failed opening shared memory %s.", getpid(), fn);
+                LOG_DBG("%d failed opening shared memory %s.", getpid(), fn);
                 return NULL;
         }
 
@@ -174,22 +178,22 @@ struct shm_ap_rbuff * shm_ap_rbuff_open(pid_t api)
                         0);
 
         if (shm_base == MAP_FAILED) {
-                LOG_DBGF("Failed to map shared memory.");
+                LOG_DBG("Failed to map shared memory.");
                 if (close(shm_fd) == -1)
-                        LOG_DBGF("Failed to close invalid shm.");
+                        LOG_DBG("Failed to close invalid shm.");
 
                 if (shm_unlink(fn) == -1)
-                        LOG_DBGF("Failed to remove invalid shm.");
+                        LOG_DBG("Failed to remove invalid shm.");
 
                 free(rb);
                 return NULL;
         }
 
-        rb->shm_base  = shm_base;
-        rb->ptr_head  = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE);
-        rb->ptr_tail  = rb->ptr_head + 1;
-        rb->shm_mutex = (pthread_mutex_t *) (rb->ptr_tail + 1);
-        rb->work      = (pthread_cond_t *) (rb->shm_mutex + 1);
+        rb->shm_base = shm_base;
+        rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE);
+        rb->ptr_tail = rb->ptr_head + 1;
+        rb->lock     = (pthread_mutex_t *) (rb->ptr_tail + 1);
+        rb->work     = (pthread_cond_t *) (rb->lock + 1);
 
         rb->fd = shm_fd;
         rb->api = api;
@@ -199,15 +203,15 @@ struct shm_ap_rbuff * shm_ap_rbuff_open(pid_t api)
 void shm_ap_rbuff_close(struct shm_ap_rbuff * rb)
 {
         if (rb == NULL) {
-                LOG_DBGF("Bogus input. Bugging out.");
+                LOG_DBG("Bogus input. Bugging out.");
                 return;
         }
 
         if (close(rb->fd) < 0)
-                LOG_DBGF("Couldn't close shared memory.");
+                LOG_DBG("Couldn't close shared memory.");
 
         if (munmap(rb->shm_base, SHM_RBUFF_FILE_SIZE) == -1)
-                LOG_DBGF("Couldn't unmap shared memory.");
+                LOG_DBG("Couldn't unmap shared memory.");
 
         free(rb);
 }
@@ -218,7 +222,7 @@ void shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb)
         struct lockfile * lf = NULL;
 
         if (rb == NULL) {
-                LOG_DBGF("Bogus input. Bugging out.");
+                LOG_DBG("Bogus input. Bugging out.");
                 return;
         }
 
@@ -227,7 +231,7 @@ void shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb)
                 if (lf == NULL)
                         return;
                 if (lockfile_owner(lf) == getpid()) {
-                        LOG_DBGF("Ringbuffer %d destroyed by IRMd %d.",
+                        LOG_DBG("Ringbuffer %d destroyed by IRMd %d.",
                                  rb->api, getpid());
                         lockfile_close(lf);
                 } else {
@@ -238,16 +242,19 @@ void shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb)
                 }
         }
 
+        pthread_mutex_destroy(rb->lock);
+        pthread_cond_destroy(rb->work);
+
         if (close(rb->fd) < 0)
-                LOG_DBGF("Couldn't close shared memory.");
+                LOG_DBG("Couldn't close shared memory.");
 
         sprintf(fn, SHM_AP_RBUFF_PREFIX "%d", rb->api);
 
         if (munmap(rb->shm_base, SHM_RBUFF_FILE_SIZE) == -1)
-                LOG_DBGF("Couldn't unmap shared memory.");
+                LOG_DBG("Couldn't unmap shared memory.");
 
         if (shm_unlink(fn) == -1)
-                LOG_DBGF("Failed to unlink shm.");
+                LOG_DBG("Failed to unlink shm.");
 
         free(rb);
 }
@@ -257,13 +264,13 @@ int shm_ap_rbuff_write(struct shm_ap_rbuff * rb, struct rb_entry * e)
         if (rb == NULL || e == NULL)
                 return -1;
 
-        if (pthread_mutex_lock(rb->shm_mutex) == EOWNERDEAD) {
-                LOG_DBGF("Recovering dead mutex.");
-                pthread_mutex_consistent(rb->shm_mutex);
+        if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+                LOG_DBG("Recovering dead mutex.");
+                pthread_mutex_consistent(rb->lock);
         }
 
         if (!shm_rbuff_free(rb)) {
-                pthread_mutex_unlock(rb->shm_mutex);
+                pthread_mutex_unlock(rb->lock);
                 return -1;
         }
 
@@ -273,11 +280,59 @@ int shm_ap_rbuff_write(struct shm_ap_rbuff * rb, struct rb_entry * e)
         *head_el_ptr = *e;
         *rb->ptr_head = (*rb->ptr_head + 1) & (SHM_RBUFF_SIZE -1);
 
-        pthread_mutex_unlock(rb->shm_mutex);
+        pthread_mutex_unlock(rb->lock);
 
         return 0;
 }
 
+int shm_ap_rbuff_peek(struct shm_ap_rbuff * rb,
+                      const struct timespec * timeout)
+{
+        struct timespec abstime;
+        int ret = 0;
+
+        if (rb == NULL)
+                return -EINVAL;
+
+        if (timeout != NULL) {
+                clock_gettime(PTHREAD_COND_CLOCK, &abstime);
+                ts_add(&abstime, timeout, &abstime);
+        }
+
+        pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
+                             (void *) rb->lock);
+
+        if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+                LOG_DBG("Recovering dead mutex.");
+                pthread_mutex_consistent(rb->lock);
+        }
+
+        while (shm_rbuff_empty(rb)) {
+                if (timeout != NULL)
+                        ret = pthread_cond_timedwait(rb->work,
+                                                     rb->lock,
+                                                     &abstime);
+                else
+                        ret = pthread_cond_wait(rb->work, rb->lock);
+
+                if (ret == EOWNERDEAD) {
+                        LOG_DBG("Recovering dead mutex.");
+                        pthread_mutex_consistent(rb->lock);
+                }
+
+                if (ret == ETIMEDOUT) {
+                        pthread_mutex_unlock(rb->lock);
+                        return -ret;
+                }
+        }
+
+        ret = (rb->shm_base + *rb->ptr_tail)->port_id;
+
+        pthread_cleanup_pop(true);
+
+        return ret;
+}
+
 struct rb_entry * shm_ap_rbuff_read(struct shm_ap_rbuff * rb)
 {
         struct rb_entry * e = NULL;
@@ -286,26 +341,25 @@ struct rb_entry * shm_ap_rbuff_read(struct shm_ap_rbuff * rb)
                 return NULL;
 
         pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
-                             (void *) rb->shm_mutex);
+                             (void *) rb->lock);
 
-        if (pthread_mutex_lock(rb->shm_mutex) == EOWNERDEAD) {
-                LOG_DBGF("Recovering dead mutex.");
-                pthread_mutex_consistent(rb->shm_mutex);
+        if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+                LOG_DBG("Recovering dead mutex.");
+                pthread_mutex_consistent(rb->lock);
         }
 
-        while (tail_el_ptr->port_id < 0)
+        while (!shm_rbuff_empty(rb) && tail_el_ptr->port_id < 0)
                 *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1);
 
         while (shm_rbuff_empty(rb))
-                if (pthread_cond_wait(rb->work, rb->shm_mutex)
-                    == EOWNERDEAD) {
-                LOG_DBGF("Recovering dead mutex.");
-                pthread_mutex_consistent(rb->shm_mutex);
+                if (pthread_cond_wait(rb->work, rb->lock) == EOWNERDEAD) {
+                LOG_DBG("Recovering dead mutex.");
+                pthread_mutex_consistent(rb->lock);
         }
 
         e = malloc(sizeof(*e));
         if (e == NULL) {
-                pthread_mutex_unlock(rb->shm_mutex);
+                pthread_mutex_unlock(rb->lock);
                 return NULL;
         }
 
@@ -313,7 +367,7 @@ struct rb_entry * shm_ap_rbuff_read(struct shm_ap_rbuff * rb)
 
         *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1);
 
-        pthread_cleanup_pop(1);
+        pthread_cleanup_pop(true);
 
         return e;
 }
@@ -322,13 +376,13 @@ ssize_t shm_ap_rbuff_read_port(struct shm_ap_rbuff * rb, int port_id)
 {
         ssize_t idx = -1;
 
-        if (pthread_mutex_lock(rb->shm_mutex) == EOWNERDEAD) {
-                LOG_DBGF("Recovering dead mutex.");
-                pthread_mutex_consistent(rb->shm_mutex);
+        if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+                LOG_DBG("Recovering dead mutex.");
+                pthread_mutex_consistent(rb->lock);
         }
 
         if (shm_rbuff_empty(rb)) {
-                pthread_mutex_unlock(rb->shm_mutex);
+                pthread_mutex_unlock(rb->lock);
                 return -1;
         }
 
@@ -336,7 +390,7 @@ ssize_t shm_ap_rbuff_read_port(struct shm_ap_rbuff * rb, int port_id)
                 *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1);
 
         if (tail_el_ptr->port_id != port_id) {
-                pthread_mutex_unlock(rb->shm_mutex);
+                pthread_mutex_unlock(rb->lock);
                 return -1;
         }
 
@@ -344,7 +398,7 @@ ssize_t shm_ap_rbuff_read_port(struct shm_ap_rbuff * rb, int port_id)
 
         *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1);
 
-        pthread_mutex_unlock(rb->shm_mutex);
+        pthread_mutex_unlock(rb->lock);
 
         return idx;
 }
@@ -355,9 +409,9 @@ pid_t shm_ap_rbuff_get_api(struct shm_ap_rbuff *rb)
         if (rb == NULL)
                 return -1;
 
-        pthread_mutex_lock(rb->shm_mutex);
+        pthread_mutex_lock(rb->lock);
         api = rb->api;
-        pthread_mutex_unlock(rb->shm_mutex);
+        pthread_mutex_unlock(rb->lock);
 
         return api;
 }
@@ -367,8 +421,8 @@ void shm_ap_rbuff_reset(struct shm_ap_rbuff * rb)
         if (rb == NULL)
                 return;
 
-        pthread_mutex_lock(rb->shm_mutex);
+        pthread_mutex_lock(rb->lock);
         *rb->ptr_tail = 0;
         *rb->ptr_head = 0;
-        pthread_mutex_unlock(rb->shm_mutex);
+        pthread_mutex_unlock(rb->lock);
 }
diff --git a/src/lib/shm_du_map.c b/src/lib/shm_du_map.c
index 6dc4a1bd..b090bb74 100644
--- a/src/lib/shm_du_map.c
+++ b/src/lib/shm_du_map.c
@@ -416,7 +416,7 @@ ssize_t shm_du_map_write(struct shm_du_map * dum,
         int                  sz = size + sizeof *sdb;
 #endif
         uint8_t *            write_pos;
-        ssize_t              index = -1;
+        ssize_t              idx = -1;
 
         if (dum == NULL || data == NULL) {
                 LOG_DBGF("Bogus input, bugging out.");
@@ -475,7 +475,7 @@ ssize_t shm_du_map_write(struct shm_du_map * dum,
 
         memcpy(write_pos, data, len);
 
-        index = *dum->ptr_head;
+        idx = *dum->ptr_head;
 #ifdef SHM_DU_MAP_MULTI_BLOCK
         *dum->ptr_head = (*dum->ptr_head + blocks) & (SHM_BLOCKS_IN_MAP - 1);
 #else
@@ -483,7 +483,7 @@ ssize_t shm_du_map_write(struct shm_du_map * dum,
 #endif
         pthread_mutex_unlock(dum->shm_mutex);
 
-        return index;
+        return idx;
 }
 
 int shm_du_map_read(uint8_t **          dst,
diff --git a/src/tools/CMakeLists.txt b/src/tools/CMakeLists.txt
index 9f5e6fbe..e8c24557 100644
--- a/src/tools/CMakeLists.txt
+++ b/src/tools/CMakeLists.txt
@@ -1,3 +1,4 @@
 add_subdirectory(irm)
 add_subdirectory(echo)
 add_subdirectory(cbr)
+add_subdirectory(oping)
diff --git a/src/tools/oping/CMakeLists.txt b/src/tools/oping/CMakeLists.txt
new file mode 100644
index 00000000..a8fc7d86
--- /dev/null
+++ b/src/tools/oping/CMakeLists.txt
@@ -0,0 +1,21 @@
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+include_directories(${CMAKE_SOURCE_DIR}/include)
+include_directories(${CMAKE_BINARY_DIR}/include)
+
+find_library(LIBM_LIBRARIES m)
+if(NOT LIBM_LIBRARIES)
+  message(FATAL_ERROR "libm not found")
+endif()
+
+set(SOURCE_FILES
+        # Add source files here
+        oping.c
+)
+
+add_executable(oping ${SOURCE_FILES})
+
+target_link_libraries(oping LINK_PUBLIC ${LIBM_LIBRARIES} ouroboros)
+
+install(TARGETS oping RUNTIME DESTINATION usr/bin)
diff --git a/src/tools/oping/oping.c b/src/tools/oping/oping.c
new file mode 100644
index 00000000..cf8dc485
--- /dev/null
+++ b/src/tools/oping/oping.c
@@ -0,0 +1,176 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Ouroboros ping application
+ *
+ *    Dimitri Staessens <dimitri.staessens@intec.ugent.be>
+ *    Sander Vrijders   <sander.vrijders@intec.ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#define _POSIX_C_SOURCE 199506L
+
+#include <stdio.h>
+#include <string.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#define OPING_BUF_SIZE 1500
+
+#define ECHO_REQUEST 0
+#define ECHO_REPLY 1
+
+#define OPING_MAX_FLOWS 256
+
+struct c {
+        char * s_apn;
+        int    interval;
+        int    count;
+        int    size;
+
+        /* stats */
+        int    sent;
+        int    rcvd;
+        float  rtt_min;
+        float  rtt_max;
+        float  rtt_avg;
+        float  rtt_m2;
+
+        /* needs locking */
+        struct timespec * times;
+        pthread_mutex_t lock;
+
+        pthread_t reader_pt;
+        pthread_t writer_pt;
+} client;
+
+struct s {
+        struct timespec times[OPING_MAX_FLOWS];
+        pthread_mutex_t lock;
+
+        pthread_t cleaner_pt;
+        pthread_t accept_pt;
+        pthread_t server_pt;
+} server;
+
+struct oping_msg {
+        uint32_t type;
+        uint32_t id;
+};
+
+
+#include "oping_client.c"
+#include "oping_server.c"
+
+static void usage()
+{
+        printf("Usage: oping [OPTION]...\n"
+               "Checks liveness between a client and a server\n"
+               "and reports the Round Trip Time (RTT)\n\n"
+               "  -l, --listen              Run in server mode\n"
+               "\n"
+               "  -c, --count               Number of packets (default 1000)\n"
+               "  -i, --interval            Interval (ms, default 1000)\n"
+               "  -n, --server-apn          Name of the oping server\n"
+               "  -s, --size                Payload size (b, default 64)\n"
+               "      --help                Display this help text and exit\n");
+}
+
+int main(int argc, char ** argv)
+{
+        int ret = -1;
+        char * rem = NULL;
+        bool serv = false;
+
+        if (ap_init(argv[0])) {
+                printf("Failed to init AP.\n");
+                exit(EXIT_FAILURE);
+        }
+
+        argc--;
+        argv++;
+
+        client.s_apn = NULL;
+        client.interval = 1000;
+        client.size = 64;
+        client.count = 1000;
+
+        while (argc > 0) {
+                if (strcmp(*argv, "-i") == 0 ||
+                    strcmp(*argv, "--interval") == 0) {
+                        client.interval = strtol(*(++argv), &rem, 10);
+                        --argc;
+                } else if (strcmp(*argv, "-n") == 0 ||
+                           strcmp(*argv, "--server_apn") == 0) {
+                        client.s_apn = *(++argv);
+                        --argc;
+                } else if (strcmp(*argv, "-c") == 0 ||
+                           strcmp(*argv, "--count") == 0) {
+                        client.count = strtol(*(++argv), &rem, 10);
+                        --argc;
+                } else if (strcmp(*argv, "-s") == 0 ||
+                           strcmp(*argv, "--size") == 0) {
+                        client.size = strtol(*(++argv), &rem, 10);
+                        --argc;
+                } else if (strcmp(*argv, "-l") == 0 ||
+                           strcmp(*argv, "--listen") == 0) {
+                        serv = true;
+                } else {
+                        usage();
+                        exit(EXIT_SUCCESS);
+                }
+                argc--;
+                argv++;
+        }
+
+        if (serv) {
+                ret = server_main();
+        } else {
+                if (client.s_apn == NULL) {
+                        printf("No server specified.\n");
+                        usage();
+                        exit(EXIT_SUCCESS);
+                }
+                if (client.interval > 10000) {
+                        printf("Ping interval truncated to 10s.\n");
+                        client.interval = 10000;
+                }
+                if (client.size > OPING_BUF_SIZE) {
+                        printf("Packet size truncated to 1500 bytes.\n");
+                        client.size = 1500;
+                }
+
+                if (client.size < 2) {
+                        printf("Packet size set to 64 bytes.\n");
+                        client.size = 64;
+                }
+
+                if (client.count > 1000000) {
+                        printf("Count truncated to 1 million SDUs.\n");
+                        client.count = 1000000;
+                }
+
+                ret = client_main();
+        }
+
+        ap_fini();
+
+        if (ret < 0)
+                exit(EXIT_FAILURE);
+
+        exit(EXIT_SUCCESS);
+}
diff --git a/src/tools/oping/oping_client.c b/src/tools/oping/oping_client.c
new file mode 100644
index 00000000..23a57549
--- /dev/null
+++ b/src/tools/oping/oping_client.c
@@ -0,0 +1,234 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Ouroboros ping application
+ *
+ *    Dimitri Staessens <dimitri.staessens@intec.ugent.be>
+ *    Sander Vrijders   <sander.vrijders@intec.ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <ouroboros/dev.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/time_utils.h>
+
+#ifdef __FreeBSD__
+#define __XSI_VISIBLE 500
+#endif
+
+#include <signal.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <arpa/inet.h>
+#include <math.h>
+#include <float.h>
+
+void shutdown_client(int signo, siginfo_t * info, void * c)
+{
+        switch(signo) {
+        case SIGINT:
+        case SIGTERM:
+        case SIGHUP:
+                pthread_cancel(client.reader_pt);
+                pthread_cancel(client.writer_pt);
+        default:
+                return;
+        }
+}
+
+void * reader(void * o)
+{
+        struct timespec timeout = {2, 0};
+        struct timespec now = {0, 0};
+
+        struct oping_msg * msg;
+        char buf[OPING_BUF_SIZE];
+        int fd = 0;
+        int msg_len = 0;
+        float ms = 0;
+        float d = 0;
+
+        msg = (struct oping_msg *) buf;
+
+        /* FIXME: use flow timeout option once we have it */
+        while(client.rcvd != client.count &&
+              (fd = flow_select(&timeout)) != -ETIMEDOUT) {
+                flow_cntl(fd, FLOW_F_SETFL, FLOW_O_NONBLOCK);
+                while (!((msg_len = flow_read(fd, buf, OPING_BUF_SIZE)) < 0)) {
+                        if (msg_len < 0)
+                                continue;
+
+                        if (ntohl(msg->type) != ECHO_REPLY) {
+                                printf("Invalid message received (%d).\n",
+                                       msg->type);
+                                continue;
+                        }
+
+                        if (ntohl(msg->id) >= client.count) {
+                                printf("Invalid id.\n");
+                                continue;
+                        }
+
+                        ++client.rcvd;
+
+                        clock_gettime(CLOCK_REALTIME, &now);
+
+                        pthread_mutex_lock(&client.lock);
+                        ms = ts_diff_us(&client.times[ntohl(msg->id)], &now)
+                                /1000.0;
+                        pthread_mutex_unlock(&client.lock);
+
+                        printf("%d bytes from %s: seq=%d time=%.3f ms\n",
+                               msg_len,
+                               client.s_apn,
+                               ntohl(msg->id),
+                               ms);
+
+                        if (ms < client.rtt_min)
+                                client.rtt_min = ms;
+                        if (ms > client.rtt_max)
+                                client.rtt_max = ms;
+
+                        d = (ms - client.rtt_avg);
+                        client.rtt_avg += d  / (float) client.rcvd;
+                        client.rtt_m2 += d * (ms - client.rtt_avg);
+                }
+        }
+
+        return (void *) 0;
+}
+
+void * writer(void * o)
+{
+        int * fdp = (int *) o;
+        struct timespec now;
+        struct timespec wait = {client.interval / 1000, client.interval % 1000};
+        struct oping_msg * msg;
+        char * buf = malloc(client.size);
+
+        if (buf == NULL)
+                return (void *) -ENOMEM;
+
+        if (fdp == NULL)
+                return (void *) -EINVAL;
+
+        memset(buf, 0, client.size);
+
+        msg = (struct oping_msg *) buf;
+
+        printf("Pinging %s with %d bytes of data:\n\n",
+               client.s_apn, client.size);
+
+        while (client.sent < client.count) {
+                nanosleep(&wait, NULL);
+                msg->id = htonl(client.sent);
+                if (flow_write(*fdp, buf, client.size) == -1) {
+                        printf("Failed to send SDU.\n");
+                        flow_dealloc(*fdp);
+                        return (void *) -1;
+                }
+
+                clock_gettime(CLOCK_REALTIME, &now);
+
+                pthread_mutex_lock(&client.lock);
+                client.times[client.sent++] = now;
+                pthread_mutex_unlock(&client.lock);
+        }
+
+        return (void *) 0;
+}
+
+int client_main()
+{
+        struct sigaction sig_act;
+
+        struct timespec tic;
+        struct timespec toc;
+
+        int fd = flow_alloc(client.s_apn, NULL, NULL);
+        if (fd < 0) {
+                printf("Failed to allocate flow.\n");
+                return -1;
+        }
+
+        if (flow_alloc_res(fd)) {
+                printf("Flow allocation refused.\n");
+                flow_dealloc(fd);
+                return -1;
+        }
+
+        memset(&sig_act, 0, sizeof sig_act);
+        sig_act.sa_sigaction = &shutdown_client;
+        sig_act.sa_flags = 0;
+
+        if (sigaction(SIGINT,  &sig_act, NULL) ||
+            sigaction(SIGTERM, &sig_act, NULL) ||
+            sigaction(SIGHUP,  &sig_act, NULL) ||
+            sigaction(SIGPIPE, &sig_act, NULL)) {
+                printf("Failed to install sighandler.\n");
+                return -1;
+        }
+
+        pthread_mutex_init(&client.lock, NULL);
+        pthread_mutex_lock(&client.lock);
+        client.sent = 0;
+        client.rcvd = 0;
+        client.rtt_min = FLT_MAX;
+        client.rtt_max = 0;
+        client.rtt_avg = 0;
+        client.rtt_m2 = 0;
+        client.times = malloc(sizeof(struct timespec) * client.count);
+        if (client.times == NULL) {
+                pthread_mutex_unlock(&client.lock);
+                return -ENOMEM;
+        }
+
+        pthread_mutex_unlock(&client.lock);
+
+        clock_gettime(CLOCK_REALTIME, &tic);
+
+        pthread_create(&client.reader_pt, NULL, reader, NULL);
+        pthread_create(&client.writer_pt, NULL, writer, &fd);
+
+        pthread_join(client.writer_pt, NULL);
+        pthread_join(client.reader_pt, NULL);
+
+        clock_gettime(CLOCK_REALTIME, &toc);
+
+        printf("\n");
+        printf("--- %s ping statistics ---\n", client.s_apn);
+        printf("%d SDU's transmitted, ", client.sent);
+        printf("%d received, ", client.rcvd);
+        printf("%d%% packet loss, ", 100 - ((100 * client.rcvd) / client.sent));
+        printf("time: %.3f ms\n", ts_diff_us(&tic, &toc) / 1000.0);
+        printf("rtt min/avg/max/mdev = %.3f/%.3f/%.3f/",
+               client.rtt_min,
+               client.rtt_avg,
+               client.rtt_max);
+        client.rcvd > 1 ?
+                printf("%.3f ms\n",
+                       sqrt(client.rtt_m2 / (float) (client.rcvd - 1))) :
+                printf("Nan ms\n");
+
+        pthread_mutex_lock(&client.lock);
+        free(client.times);
+        pthread_mutex_unlock(&client.lock);
+        pthread_mutex_destroy(&client.lock);
+
+        flow_dealloc(fd);
+
+        return 0;
+}
diff --git a/src/tools/oping/oping_server.c b/src/tools/oping/oping_server.c
new file mode 100644
index 00000000..eb0b511b
--- /dev/null
+++ b/src/tools/oping/oping_server.c
@@ -0,0 +1,162 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Ouroboros ping application
+ *
+ *    Dimitri Staessens <dimitri.staessens@intec.ugent.be>
+ *    Sander Vrijders   <sander.vrijders@intec.ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <ouroboros/dev.h>
+
+#ifdef __FreeBSD__
+#define __XSI_VISIBLE 500
+#endif
+
+#include <stdlib.h>
+#include <signal.h>
+#include <arpa/inet.h>
+
+void shutdown_server(int signo, siginfo_t * info, void * c)
+{
+        switch(signo) {
+        case SIGINT:
+        case SIGTERM:
+        case SIGHUP:
+                pthread_cancel(server.server_pt);
+                pthread_cancel(server.accept_pt);
+                pthread_cancel(server.cleaner_pt);
+        default:
+                return;
+        }
+}
+
+void * cleaner_thread(void * o)
+{
+        int i = 0;
+        struct timespec now = {0, 0};
+        int deadline_ms = 10000;
+
+        while (true) {
+                clock_gettime(CLOCK_REALTIME, &now);
+                pthread_mutex_lock(&server.lock);
+                for (i = 0; i < OPING_MAX_FLOWS; ++i)
+                        if (ts_diff_ms(&server.times[i], &now) > deadline_ms)
+                                flow_dealloc(i);
+
+                pthread_mutex_unlock(&server.lock);
+                sleep(1);
+        }
+}
+
+void * server_thread(void *o)
+{
+        char buf[OPING_BUF_SIZE];
+        int msg_len = 0;
+        struct oping_msg * msg = (struct oping_msg *) buf;
+        struct timespec now = {0, 0};
+
+        while (true) {
+
+                int fd = flow_select(NULL);
+                while (!((msg_len = flow_read(fd, buf, OPING_BUF_SIZE)) < 0)) {
+                        if (msg_len < 0)
+                                continue;
+
+                        if (ntohl(msg->type) != ECHO_REQUEST) {
+                                printf("Invalid message received.\n");
+                                continue;
+                        }
+
+                        clock_gettime(CLOCK_REALTIME, &now);
+
+                        pthread_mutex_lock(&server.lock);
+                        server.times[fd] = now;
+                        pthread_mutex_unlock(&server.lock);
+
+                        msg->type = htonl((uint32_t) ECHO_REPLY);
+
+                        if (flow_write(fd, buf, msg_len) < 0) {
+                                printf("Error writing to flow (fd %d).\n", fd);
+                                flow_dealloc(fd);
+                        }
+                }
+        }
+
+        return (void *) 0;
+}
+
+void * accept_thread(void * o)
+{
+        int fd = 0;
+        struct timespec now = {0, 0};
+
+        printf("Ouroboros ping server started.\n");
+
+        while (true) {
+                fd = flow_accept(NULL);
+                if (fd < 0) {
+                        printf("Failed to accept flow.\n");
+                        break;
+                }
+
+                printf("New flow %d.\n", fd);
+
+                if (flow_alloc_resp(fd, 0)) {
+                        printf("Failed to give an allocate response.\n");
+                        flow_dealloc(fd);
+                        continue;
+                }
+
+                clock_gettime(CLOCK_REALTIME, &now);
+
+                pthread_mutex_lock(&server.lock);
+                server.times[fd] = now;
+                pthread_mutex_unlock(&server.lock);
+
+                flow_cntl(fd, FLOW_F_SETFL, FLOW_O_NONBLOCK);
+        }
+
+        return (void *) 0;
+}
+
+int server_main()
+{
+        struct sigaction sig_act;
+
+        memset(&sig_act, 0, sizeof sig_act);
+        sig_act.sa_sigaction = &shutdown_server;
+        sig_act.sa_flags = 0;
+
+        if (sigaction(SIGINT,  &sig_act, NULL) ||
+            sigaction(SIGTERM, &sig_act, NULL) ||
+            sigaction(SIGHUP,  &sig_act, NULL) ||
+            sigaction(SIGPIPE, &sig_act, NULL)) {
+                printf("Failed to install sighandler.\n");
+                return -1;
+        }
+
+        pthread_create(&server.cleaner_pt, NULL, cleaner_thread, NULL);
+        pthread_create(&server.accept_pt, NULL, accept_thread, NULL);
+        pthread_create(&server.server_pt, NULL, server_thread, NULL);
+
+        pthread_join(server.server_pt, NULL);
+        pthread_join(server.accept_pt, NULL);
+        pthread_join(server.cleaner_pt, NULL);
+
+        return 0;
+}