ipcpd: flow structure for maintaining flows

The flow structure can be used to maintain the status of flows in ipcp
instances. It should probably not be exposed outside ipcpd's.

It has a flag FLOW_MT_SAFE which includes locking in case the IPCP has
a multithreaded implementation that may require it.

3 files changed, 150 insertions, 0 deletions

diff --git a/src/ipcpd/CMakeLists.txt b/src/ipcpd/CMakeLists.txt
index bcb5b986..27d41801 100644
--- a/src/ipcpd/CMakeLists.txt
+++ b/src/ipcpd/CMakeLists.txt
@@ -9,6 +9,7 @@ set(SOURCE_FILES
         main.c
         pci.c
         shm_pci.c
+        flow.c
 )
 
 add_executable (ipcpd ${SOURCE_FILES})
diff --git a/src/ipcpd/flow.c b/src/ipcpd/flow.c
new file mode 100644
index 00000000..395a0a0d
--- /dev/null
+++ b/src/ipcpd/flow.c
@@ -0,0 +1,83 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Flows
+ *
+ *    Dimitri Staessens <[email protected]>
+ *
+ * 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 "flow.h"
+#include <malloc.h>
+
+#define OUROBOROS_PREFIX "ipcpd/flow"
+
+#include <ouroboros/logs.h>
+
+flow_t * flow_create(port_id_t port_id)
+{
+        flow_t * flow = malloc(sizeof *flow);
+        flow->port_id = port_id;
+        flow->flags = FLOW_O_DEFAULT;
+        flow->state = FLOW_INIT;
+
+#ifdef FLOW_MT_SAFE
+        pthread_mutex_init(&flow->lock, NULL);
+#endif
+        return flow;
+}
+
+void flow_destroy(flow_t * flow)
+{
+        free(flow);
+}
+
+int flow_set_opts(flow_t * flow, uint16_t opts)
+{
+        if (flow == NULL) {
+                LOG_ERR("Non-existing flow.");
+                return -1;
+        }
+
+#ifdef FLOW_MT_SAFE
+        pthread_mutex_lock(&flow->lock);
+#endif
+
+        if ((opts & FLOW_O_ACCMODE) == FLOW_O_ACCMODE) {
+#ifdef FLOW_MT_SAFE
+                pthread_mutex_unlock(&flow->lock);
+#endif
+                LOG_WARN("Invalid flow options. Setting default.");
+                opts = FLOW_O_DEFAULT;
+        }
+
+        flow->flags = opts;
+
+#ifdef FLOW_MT_SAFE
+                pthread_mutex_unlock(&flow->lock);
+#endif
+        return 0;
+}
+
+uint16_t flow_get_opts(const flow_t * flow)
+{
+        if (flow == NULL) {
+                LOG_ERR("Non-existing flow.");
+                return FLOW_O_INVALID;
+        }
+
+        return flow->flags;
+}
diff --git a/src/ipcpd/flow.h b/src/ipcpd/flow.h
new file mode 100644
index 00000000..83f4076d
--- /dev/null
+++ b/src/ipcpd/flow.h
@@ -0,0 +1,66 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Flows
+ *
+ *    Dimitri Staessens <[email protected]>
+ *
+ * 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.
+ */
+
+#ifndef IPCPD_FLOW_H
+#define IPCPD_FLOW_H
+
+#include <ouroboros/common.h>
+
+#ifdef FLOW_MT_SAFE
+#include <pthread.h>
+#endif
+
+/* same values as fcntl.h */
+#define FLOW_O_RDONLY   00000000
+#define FLOW_O_WRONLY   00000001
+#define FLOW_O_RDWR     00000002
+#define FLOW_O_ACCMODE  00000003
+
+#define FLOW_O_NONBLOCK 00004000
+#define FLOW_O_DEFAULT  00000002
+
+#define FLOW_O_INVALID  00037777
+
+typedef long port_id_t;
+
+enum flow_state {
+        FLOW_INIT = 0,
+        FLOW_ALLOCATED,
+        FLOW_PENDING
+};
+
+typedef struct flow {
+        port_id_t       port_id;
+        uint16_t        flags;
+        uint8_t         state;
+#ifdef FLOW_MT_SAFE
+        pthread_mutex_t lock;
+#endif
+} flow_t;
+
+flow_t * flow_create(port_id_t port_id);
+void     flow_destroy(flow_t * flow);
+
+int      flow_set_opts(flow_t * flow, uint16_t opts);
+uint16_t flow_get_opts(const flow_t * flow);
+
+#endif /* IPCPD_FLOW_H */