ipcpd: normal: Complete flat address policy

This will add a check in the flat address policy to see if the address
is in use or not.

1 files changed, 261 insertions, 0 deletions

diff --git a/src/ipcpd/normal/pol/flat.c b/src/ipcpd/normal/pol/flat.c
new file mode 100644
index 00000000..4946d538
--- /dev/null
+++ b/src/ipcpd/normal/pol/flat.c
@@ -0,0 +1,261 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Policy for flat addresses in a distributed way
+ *
+ *    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 OUROBOROS_PREFIX "flat-addr-auth"
+
+#include <ouroboros/config.h>
+#include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/time_utils.h>
+
+#include <time.h>
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include <assert.h>
+
+#include "shm_pci.h"
+#include "ribmgr.h"
+#include "ro.h"
+
+#define POL_RO_ROOT "/flat_addr"
+
+#define TIMEOUT  100 /* ms */
+#define STR_SIZE 100
+
+#define FLAT_ADDR_REQ   0
+#define FLAT_ADDR_REPLY 1
+
+struct flat_addr_msg {
+        uint8_t  code;
+        uint64_t addr;
+};
+
+struct {
+        int      sid;
+        uint64_t addr;
+        bool     addr_in_use;
+
+        pthread_cond_t  cond;
+        pthread_mutex_t lock;
+} flat;
+
+static char * my_name(void)
+{
+        char * name;
+        char addr_name[100];
+
+        name = malloc(STR_SIZE);
+        if (name == NULL)
+                return NULL;
+
+        sprintf(addr_name, "%lu", (unsigned long) flat.addr);
+        strcpy(name, POL_RO_ROOT);
+        strcat(name, "/");
+        strcat(name, addr_name);
+
+        return name;
+}
+
+/* FIXME: We should return void */
+static int ro_created(const char * name,
+                      uint8_t *    data,
+                      size_t       len)
+{
+        struct flat_addr_msg * msg;
+
+        assert(name);
+        assert(data);
+        assert(len >= sizeof(*msg));
+
+        msg = (struct flat_addr_msg *) data;
+        if (msg->code == FLAT_ADDR_REQ &&
+            msg->addr == flat.addr) {
+                msg->code = FLAT_ADDR_REPLY;
+                ro_write(name, data, len);
+        }
+
+        return 0;
+}
+
+static int ro_updated(const char * name,
+                      uint8_t *    data,
+                      size_t       len)
+{
+        struct flat_addr_msg * msg;
+        char * ro_name;
+
+        assert(name);
+        assert(data);
+        assert(len >= sizeof(*msg));
+
+        ro_name = my_name();
+        if (ro_name == NULL)
+                return -1;
+
+        msg = (struct flat_addr_msg *) data;
+        if (msg->code == FLAT_ADDR_REPLY &&
+            strcmp(name, ro_name) == 0) {
+                pthread_mutex_lock(&flat.lock);
+                flat.addr_in_use = true;
+                pthread_cond_broadcast(&flat.cond);
+                pthread_mutex_unlock(&flat.lock);
+        }
+
+        free(data);
+        free(ro_name);
+
+        return 0;
+}
+
+static struct ro_sub_ops flat_sub_ops = {
+        .ro_created = ro_created,
+        .ro_updated = ro_updated,
+        .ro_deleted = NULL
+};
+
+int flat_init(void)
+{
+        struct ro_props * props;
+        pthread_condattr_t cattr;
+
+        srand(time(NULL));
+        flat.addr_in_use = false;
+
+        props = malloc(sizeof(*props));
+        if (props == NULL)
+                return -ENOMEM;
+
+        pthread_mutex_init(&flat.lock, NULL);
+        pthread_condattr_init(&cattr);
+#ifndef __APPLE__
+        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
+#endif
+        pthread_cond_init(&flat.cond, &cattr);
+
+        flat.sid = ro_subscribe(POL_RO_ROOT,
+                                &flat_sub_ops);
+        if (flat.sid < 0) {
+                LOG_ERR("Could not subscribe to RIB.");
+                pthread_cond_destroy(&flat.cond);
+                pthread_mutex_destroy(&flat.lock);
+                free(props);
+                return -1;
+        }
+
+        props->enrol_sync = false;
+        props->recv_set = NO_SYNC;
+        props->expiry.tv_sec = 0;
+        props->expiry.tv_nsec = 0;
+
+        if (ro_create(POL_RO_ROOT, props, NULL, 0)) {
+                LOG_ERR("Could not create RO.");
+                pthread_cond_destroy(&flat.cond);
+                pthread_mutex_destroy(&flat.lock);
+                free(props);
+                ro_unsubscribe(flat.sid);
+                return -1;
+        }
+
+        return 0;
+}
+
+int flat_fini(void)
+{
+        pthread_cond_destroy(&flat.cond);
+        pthread_mutex_destroy(&flat.lock);
+        ro_unsubscribe(flat.sid);
+        return 0;
+}
+
+uint64_t flat_address(void)
+{
+        int ret = 0;
+        uint64_t max_addr;
+        struct dt_const * dtc;
+        struct timespec timeout = {(TIMEOUT / 1000),
+                                   (TIMEOUT % 1000) * MILLION};
+        struct timespec abstime;
+        struct ro_props * props;
+        struct flat_addr_msg * msg;
+        uint8_t * buf;
+        char * ro_name;
+
+        dtc = ribmgr_dt_const();
+        if (dtc == NULL)
+                return INVALID_ADDR;
+
+        while (ret != -ETIMEDOUT) {
+                clock_gettime(PTHREAD_COND_CLOCK, &abstime);
+                ts_add(&abstime, &timeout, &abstime);
+
+                max_addr = (1 << (8 * dtc->addr_size)) - 1;
+                flat.addr = (rand() % (max_addr - 1)) + 1;
+
+                /* FIXME: We must change this to stack memory */
+                props = malloc(sizeof(*props));
+                if (props == NULL)
+                        return INVALID_ADDR;
+
+                props->enrol_sync = false;
+                props->recv_set = ALL_MEMBERS;
+                props->expiry.tv_sec = TIMEOUT / 1000;
+                props->expiry.tv_nsec = (TIMEOUT % 1000) * MILLION;
+
+                buf = malloc(sizeof(*msg));
+                if (buf == NULL) {
+                        free(props);
+                        return INVALID_ADDR;
+                }
+
+                msg = (struct flat_addr_msg *) buf;
+                msg->code = FLAT_ADDR_REQ;
+                msg->addr = flat.addr;
+
+                /* FIXME: We may require functions to construct pathnames */
+                ro_name = my_name();
+                if (ro_name == NULL) {
+                        free(props);
+                        return INVALID_ADDR;
+                }
+
+                pthread_mutex_lock(&flat.lock);
+                if (ro_create(ro_name, props, buf, sizeof(*msg))) {
+                        pthread_mutex_unlock(&flat.lock);
+                        free(props);
+                        free(ro_name);
+                        return INVALID_ADDR;
+                }
+                free(ro_name);
+
+                while (flat.addr_in_use == false) {
+                        ret = -pthread_cond_timedwait(&flat.cond,
+                                                      &flat.lock,
+                                                      &abstime);
+                        if (ret == -ETIMEDOUT)
+                                break;
+                }
+                pthread_mutex_unlock(&flat.lock);
+        }
+
+        return flat.addr;
+}