lib: Set independent size for rbuff

This allows setting the size of the rbuffs in a system independently
of the main packet buffer using SHM_RBUFF_SIZE. The benefit of setting
a smaller rbuff size is that a single process can't fully occupy the
main packet buffer.

Signed-off-by: Dimitri Staessens <dimitri.staessens@ugent.be>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

6 files changed, 137 insertions, 15 deletions

diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt
index d5e80fc9..1a3c6ba3 100644
--- a/src/lib/CMakeLists.txt
+++ b/src/lib/CMakeLists.txt
@@ -139,6 +139,8 @@ mark_as_advanced(LIBRT_LIBRARIES LIBPTHREAD_LIBRARIES
 
 set(SHM_BUFFER_SIZE 4096 CACHE STRING
     "Number of blocks in packet buffer, must be a power of 2")
+set(SHM_RBUFF_SIZE 1024 CACHE STRING
+    "Number of blocks in rbuff buffer, must be a power of 2")
 set(SYS_MAX_FLOWS 10240 CACHE STRING
   "Maximum number of total flows for this system")
 set(PROG_MAX_FLOWS 4096 CACHE STRING
diff --git a/src/lib/config.h.in b/src/lib/config.h.in
index cc0845d3..3e5a7b1e 100644
--- a/src/lib/config.h.in
+++ b/src/lib/config.h.in
@@ -36,6 +36,7 @@
 #define SHM_RDRB_NAME       "@SHM_RDRB_NAME@"
 #define SHM_RDRB_BLOCK_SIZE @SHM_RDRB_BLOCK_SIZE@
 #define SHM_BUFFER_SIZE     @SHM_BUFFER_SIZE@
+#define SHM_RBUFF_SIZE      @SHM_RBUFF_SIZE@
 
 #if defined(__linux__) || (defined(__MACH__) && !defined(__APPLE__))
 /* Avoid a bug in robust mutex implementation of glibc 2.25 */
diff --git a/src/lib/dev.c b/src/lib/dev.c
index 6d5676af..ee7839c8 100644
--- a/src/lib/dev.c
+++ b/src/lib/dev.c
@@ -933,7 +933,11 @@ ssize_t flow_write(int          fd,
 
         pthread_rwlock_rdlock(&ai.lock);
 
-        ret = shm_rbuff_write(flow->tx_rb, idx);
+        if (flags & FLOWFWNOBLOCK)
+                ret = shm_rbuff_write(flow->tx_rb, idx);
+        else
+                ret = shm_rbuff_write_b(flow->tx_rb, idx, abstime);
+
         if (ret < 0)
                 shm_rdrbuff_remove(ai.rdrb, idx);
         else
@@ -1444,9 +1448,11 @@ int ipcp_flow_write(int                  fd,
                 return -ENOMEM;
         }
 
-        ret = shm_rbuff_write(flow->tx_rb, idx);
+        ret = shm_rbuff_write_b(flow->tx_rb, idx, NULL);
         if (ret == 0)
                 shm_flow_set_notify(flow->set, flow->flow_id, FLOW_PKT);
+        else
+                shm_rdrbuff_remove(ai.rdrb, idx);
 
         pthread_rwlock_unlock(&ai.lock);
 
@@ -1544,10 +1550,11 @@ int local_flow_write(int    fd,
                 pthread_rwlock_unlock(&ai.lock);
                 return -ENOTALLOC;
         }
-
-        ret = shm_rbuff_write(flow->tx_rb, idx);
+        ret = shm_rbuff_write_b(flow->tx_rb, idx, NULL);
         if (ret == 0)
                 shm_flow_set_notify(flow->set, flow->flow_id, FLOW_PKT);
+        else
+                shm_rdrbuff_remove(ai.rdrb, idx);
 
         pthread_rwlock_unlock(&ai.lock);
 
diff --git a/src/lib/shm_rbuff.c b/src/lib/shm_rbuff.c
index f7f383fc..ebae9702 100644
--- a/src/lib/shm_rbuff.c
+++ b/src/lib/shm_rbuff.c
@@ -45,14 +45,14 @@
 
 #define FN_MAX_CHARS 255
 
-#define SHM_RB_FILE_SIZE ((SHM_BUFFER_SIZE) * sizeof(ssize_t)           \
+#define SHM_RB_FILE_SIZE ((SHM_RBUFF_SIZE) * sizeof(ssize_t)            \
                           + 3 * sizeof(size_t)                          \
                           + sizeof(pthread_mutex_t)                     \
                           + 2 * sizeof (pthread_cond_t))
 
-#define shm_rbuff_used(rb) ((*rb->head + (SHM_BUFFER_SIZE) - *rb->tail)   \
-                            & ((SHM_BUFFER_SIZE) - 1))
-#define shm_rbuff_free(rb) (shm_rbuff_used(rb) + 1 < (SHM_BUFFER_SIZE))
+#define shm_rbuff_used(rb) ((*rb->head + (SHM_RBUFF_SIZE) - *rb->tail)   \
+                            & ((SHM_RBUFF_SIZE) - 1))
+#define shm_rbuff_free(rb) (shm_rbuff_used(rb) + 1 < (SHM_RBUFF_SIZE))
 #define shm_rbuff_empty(rb) (*rb->head == *rb->tail)
 #define head_el_ptr(rb) (rb->shm_base + *rb->head)
 #define tail_el_ptr(rb) (rb->shm_base + *rb->tail)
@@ -109,7 +109,7 @@ struct shm_rbuff * rbuff_create(pid_t pid,
         close(fd);
 
         rb->shm_base = shm_base;
-        rb->head     = (size_t *) (rb->shm_base + (SHM_BUFFER_SIZE));
+        rb->head     = (size_t *) (rb->shm_base + (SHM_RBUFF_SIZE));
         rb->tail     = rb->head + 1;
         rb->acl      = rb->tail + 1;
         rb->lock     = (pthread_mutex_t *) (rb->acl + 1);
diff --git a/src/lib/shm_rbuff_ll.c b/src/lib/shm_rbuff_ll.c
index 6146f178..263f4909 100644
--- a/src/lib/shm_rbuff_ll.c
+++ b/src/lib/shm_rbuff_ll.c
@@ -65,7 +65,7 @@ int shm_rbuff_write(struct shm_rbuff * rb,
 
         do {
                 ohead = nhead;
-                nhead = (ohead + 1) & ((SHM_BUFFER_SIZE) - 1);
+                nhead = (ohead + 1) & ((SHM_RBUFF_SIZE) - 1);
                 nhead = __sync_val_compare_and_swap(rb->head, ohead, nhead);
         } while (nhead != ohead);
 
@@ -75,6 +75,63 @@ int shm_rbuff_write(struct shm_rbuff * rb,
         return 0;
 }
 
+/* FIXME: this is a copy of the pthr implementation */
+int shm_rbuff_write_b(struct shm_rbuff *      rb,
+                      size_t                  idx,
+                      const struct timespec * abstime)
+{
+        int ret = 0;
+
+        assert(rb);
+        assert(idx < SHM_BUFFER_SIZE);
+
+#ifndef HAVE_ROBUST_MUTEX
+        pthread_mutex_lock(rb->lock);
+#else
+        if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
+                pthread_mutex_consistent(rb->lock);
+#endif
+
+        if (*rb->acl != ACL_RDWR) {
+                if (*rb->acl & ACL_FLOWDOWN)
+                        ret = -EFLOWDOWN;
+                else if (*rb->acl & ACL_RDONLY)
+                        ret = -ENOTALLOC;
+                goto err;
+        }
+
+        pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
+                             (void *) rb->lock);
+
+        while (!shm_rbuff_free(rb) && ret != -ETIMEDOUT) {
+                if (abstime != NULL)
+                        ret = -pthread_cond_timedwait(rb->add,
+                                                      rb->lock,
+                                                      abstime);
+                else
+                        ret = -pthread_cond_wait(rb->add, rb->lock);
+#ifdef HAVE_ROBUST_MUTEX
+                if (ret == -EOWNERDEAD)
+                        pthread_mutex_consistent(rb->lock);
+#endif
+        }
+
+        if (shm_rbuff_empty(rb))
+                pthread_cond_broadcast(rb->add);
+
+        if (ret != -ETIMEDOUT) {
+                *head_el_ptr(rb) = (ssize_t) idx;
+                *rb->head = (*rb->head + 1) & ((SHM_RBUFF_SIZE) -1);
+        }
+
+        pthread_cleanup_pop(true);
+
+        return ret;
+ err:
+        pthread_mutex_unlock(rb->lock);
+        return ret;
+}
+
 ssize_t shm_rbuff_read(struct shm_rbuff * rb)
 {
         size_t otail;
@@ -90,7 +147,7 @@ ssize_t shm_rbuff_read(struct shm_rbuff * rb)
 
         do {
                 otail = ntail;
-                ntail = (otail + 1) & ((SHM_BUFFER_SIZE) - 1);
+                ntail = (otail + 1) & ((SHM_RBUFF_SIZE) - 1);
                 ntail = __sync_val_compare_and_swap(rb->tail, otail, ntail);
         } while (ntail != otail);
 
@@ -136,7 +193,6 @@ ssize_t shm_rbuff_read_b(struct shm_rbuff *      rb,
         if (idx != -ETIMEDOUT) {
                 /* do a nonblocking read */
                 idx = shm_rbuff_read(rb);
-
                 assert(idx >= 0);
         }
 
diff --git a/src/lib/shm_rbuff_pthr.c b/src/lib/shm_rbuff_pthr.c
index b4134bf6..5a58605b 100644
--- a/src/lib/shm_rbuff_pthr.c
+++ b/src/lib/shm_rbuff_pthr.c
@@ -72,7 +72,7 @@ int shm_rbuff_write(struct shm_rbuff * rb,
                 pthread_cond_broadcast(rb->add);
 
         *head_el_ptr(rb) = (ssize_t) idx;
-        *rb->head = (*rb->head + 1) & ((SHM_BUFFER_SIZE) -1);
+        *rb->head = (*rb->head + 1) & ((SHM_RBUFF_SIZE) - 1);
 
         pthread_mutex_unlock(rb->lock);
 
@@ -82,6 +82,62 @@ int shm_rbuff_write(struct shm_rbuff * rb,
         return ret;
 }
 
+int shm_rbuff_write_b(struct shm_rbuff *      rb,
+                      size_t                  idx,
+                      const struct timespec * abstime)
+{
+        int ret = 0;
+
+        assert(rb);
+        assert(idx < SHM_BUFFER_SIZE);
+
+#ifndef HAVE_ROBUST_MUTEX
+        pthread_mutex_lock(rb->lock);
+#else
+        if (pthread_mutex_lock(rb->lock) == EOWNERDEAD)
+                pthread_mutex_consistent(rb->lock);
+#endif
+
+        if (*rb->acl != ACL_RDWR) {
+                if (*rb->acl & ACL_FLOWDOWN)
+                        ret = -EFLOWDOWN;
+                else if (*rb->acl & ACL_RDONLY)
+                        ret = -ENOTALLOC;
+                goto err;
+        }
+
+        pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
+                             (void *) rb->lock);
+
+        while (!shm_rbuff_free(rb) && ret != -ETIMEDOUT) {
+                if (abstime != NULL)
+                        ret = -pthread_cond_timedwait(rb->add,
+                                                      rb->lock,
+                                                      abstime);
+                else
+                        ret = -pthread_cond_wait(rb->add, rb->lock);
+#ifdef HAVE_ROBUST_MUTEX
+                if (ret == -EOWNERDEAD)
+                        pthread_mutex_consistent(rb->lock);
+#endif
+        }
+
+        if (shm_rbuff_empty(rb))
+                pthread_cond_broadcast(rb->add);
+
+        if (ret != -ETIMEDOUT) {
+                *head_el_ptr(rb) = (ssize_t) idx;
+                *rb->head = (*rb->head + 1) & ((SHM_RBUFF_SIZE) - 1);
+        }
+
+        pthread_cleanup_pop(true);
+
+        return ret;
+ err:
+        pthread_mutex_unlock(rb->lock);
+        return ret;
+}
+
 ssize_t shm_rbuff_read(struct shm_rbuff * rb)
 {
         ssize_t ret = 0;
@@ -102,7 +158,7 @@ ssize_t shm_rbuff_read(struct shm_rbuff * rb)
         }
 
         ret = *tail_el_ptr(rb);
-        *rb->tail = (*rb->tail + 1) & ((SHM_BUFFER_SIZE) - 1);
+        *rb->tail = (*rb->tail + 1) & ((SHM_RBUFF_SIZE) - 1);
         pthread_cond_broadcast(rb->del);
 
         pthread_mutex_unlock(rb->lock);
@@ -147,7 +203,7 @@ ssize_t shm_rbuff_read_b(struct shm_rbuff *      rb,
 
         if (idx != -ETIMEDOUT) {
                 idx = *tail_el_ptr(rb);
-                *rb->tail = (*rb->tail + 1) & ((SHM_BUFFER_SIZE) - 1);
+                *rb->tail = (*rb->tail + 1) & ((SHM_RBUFF_SIZE) - 1);
                 pthread_cond_broadcast(rb->del);
         }