build: Refactor normal to unicast

This completes the renaming of the normal IPCP to the unicast IPCP in
the sources, to get everything consistent with the documentation.

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

1 files changed, 913 insertions, 0 deletions

diff --git a/src/ipcpd/unicast/dt.c b/src/ipcpd/unicast/dt.c
new file mode 100644
index 00000000..2fd3c060
--- /dev/null
+++ b/src/ipcpd/unicast/dt.c
@@ -0,0 +1,913 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2019
+ *
+ * Data Transfer Component
+ *
+ *    Dimitri Staessens <[email protected]>
+ *    Sander Vrijders   <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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., http://www.fsf.org/about/contact/.
+ */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#define _DEFAULT_SOURCE
+#else
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include "config.h"
+
+#define DT               "dt"
+#define OUROBOROS_PREFIX DT
+
+#include <ouroboros/bitmap.h>
+#include <ouroboros/errno.h>
+#include <ouroboros/logs.h>
+#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"
+#include "dt.h"
+#include "pff.h"
+#include "routing.h"
+#include "psched.h"
+#include "comp.h"
+#include "fa.h"
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <pthread.h>
+#include <string.h>
+#include <inttypes.h>
+#include <assert.h>
+
+#define QOS_BLOCK_LEN 672
+#define STAT_FILE_LEN (189 + QOS_BLOCK_LEN * QOS_CUBE_MAX)
+
+#ifndef CLOCK_REALTIME_COARSE
+#define CLOCK_REALTIME_COARSE CLOCK_REALTIME
+#endif
+
+struct comp_info {
+        void (* post_packet)(void * comp, struct shm_du_buff * sdb);
+        void * comp;
+        char * name;
+};
+
+/* Fixed field lengths */
+#define TTL_LEN 1
+#define QOS_LEN 1
+#define ECN_LEN 1
+
+struct dt_pci {
+        uint64_t  dst_addr;
+        qoscube_t qc;
+        uint8_t   ttl;
+        uint8_t   ecn;
+        uint32_t  eid;
+};
+
+struct {
+        uint8_t         addr_size;
+        uint8_t         eid_size;
+        size_t          head_size;
+
+        /* Offsets */
+        size_t          qc_o;
+        size_t          ttl_o;
+        size_t          ecn_o;
+        size_t          eid_o;
+
+        /* Initial TTL value */
+        uint8_t         max_ttl;
+} dt_pci_info;
+
+static int dt_pci_ser(struct shm_du_buff * sdb,
+                      struct dt_pci *      dt_pci)
+{
+        uint8_t * head;
+        uint8_t   ttl = dt_pci_info.max_ttl;
+
+        assert(sdb);
+        assert(dt_pci);
+
+        head = shm_du_buff_head_alloc(sdb, dt_pci_info.head_size);
+        if (head == NULL)
+                return -EPERM;
+
+        /* FIXME: Add check and operations for Big Endian machines. */
+        memcpy(head, &dt_pci->dst_addr, dt_pci_info.addr_size);
+        memcpy(head + dt_pci_info.qc_o, &dt_pci->qc, QOS_LEN);
+        memcpy(head + dt_pci_info.ttl_o, &ttl, TTL_LEN);
+        memcpy(head + dt_pci_info.ecn_o,  &dt_pci->ecn, ECN_LEN);
+        memcpy(head + dt_pci_info.eid_o, &dt_pci->eid, dt_pci_info.eid_size);
+
+        return 0;
+}
+
+static void dt_pci_des(struct shm_du_buff * sdb,
+                       struct dt_pci *      dt_pci)
+{
+        uint8_t * head;
+
+        assert(sdb);
+        assert(dt_pci);
+
+        head = shm_du_buff_head(sdb);
+
+        /* Decrease TTL */
+        --*(head + dt_pci_info.ttl_o);
+
+        /* FIXME: Add check and operations for Big Endian machines. */
+        memcpy(&dt_pci->dst_addr, head, dt_pci_info.addr_size);
+        memcpy(&dt_pci->qc, head + dt_pci_info.qc_o, QOS_LEN);
+        memcpy(&dt_pci->ttl, head + dt_pci_info.ttl_o, TTL_LEN);
+        memcpy(&dt_pci->ecn, head + dt_pci_info.ecn_o, ECN_LEN);
+        memcpy(&dt_pci->eid, head + dt_pci_info.eid_o, dt_pci_info.eid_size);
+}
+
+static void dt_pci_shrink(struct shm_du_buff * sdb)
+{
+        assert(sdb);
+
+        shm_du_buff_head_release(sdb, dt_pci_info.head_size);
+}
+
+struct {
+        struct psched *    psched;
+
+        struct pff *       pff[QOS_CUBE_MAX];
+        struct routing_i * routing[QOS_CUBE_MAX];
+#ifdef IPCP_FLOW_STATS
+        struct {
+                time_t          stamp;
+                uint64_t        addr;
+                size_t          snd_pkt[QOS_CUBE_MAX];
+                size_t          rcv_pkt[QOS_CUBE_MAX];
+                size_t          snd_bytes[QOS_CUBE_MAX];
+                size_t          rcv_bytes[QOS_CUBE_MAX];
+                size_t          lcl_r_pkt[QOS_CUBE_MAX];
+                size_t          lcl_r_bytes[QOS_CUBE_MAX];
+                size_t          lcl_w_pkt[QOS_CUBE_MAX];
+                size_t          lcl_w_bytes[QOS_CUBE_MAX];
+                size_t          r_drp_pkt[QOS_CUBE_MAX];
+                size_t          r_drp_bytes[QOS_CUBE_MAX];
+                size_t          w_drp_pkt[QOS_CUBE_MAX];
+                size_t          w_drp_bytes[QOS_CUBE_MAX];
+                size_t          f_nhp_pkt[QOS_CUBE_MAX];
+                size_t          f_nhp_bytes[QOS_CUBE_MAX];
+                pthread_mutex_t lock;
+        } stat[PROG_MAX_FLOWS];
+
+        size_t             n_flows;
+#endif
+        struct bmp *       res_fds;
+        struct comp_info   comps[PROG_RES_FDS];
+        pthread_rwlock_t   lock;
+
+        pthread_t          listener;
+} dt;
+
+static int dt_stat_read(const char * path,
+                        char *       buf,
+                        size_t       len)
+{
+#ifdef IPCP_FLOW_STATS
+        int         fd;
+        int         i;
+        char        str[QOS_BLOCK_LEN + 1];
+        char        addrstr[20];
+        char        tmstr[20];
+        size_t      rxqlen = 0;
+        size_t      txqlen = 0;
+        struct tm * tm;
+
+        /* NOTE: we may need stronger checks. */
+        fd = atoi(path);
+
+        if (len < STAT_FILE_LEN)
+                return 0;
+
+        buf[0] = '\0';
+
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt.stat[fd].stamp == 0) {
+                pthread_mutex_unlock(&dt.stat[fd].lock);
+                return 0;
+        }
+
+        if (dt.stat[fd].addr == ipcpi.dt_addr)
+                sprintf(addrstr, "%s", dt.comps[fd].name);
+        else
+                sprintf(addrstr, "%" PRIu64, dt.stat[fd].addr);
+
+        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,
+                "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,
+                        "Qos cube %3d:\n"
+                        " sent (packets):          %20zu\n"
+                        " sent (bytes):            %20zu\n"
+                        " rcvd (packets):          %20zu\n"
+                        " rcvd (bytes):            %20zu\n"
+                        " local sent (packets):    %20zu\n"
+                        " local sent (bytes):      %20zu\n"
+                        " local rcvd (packets):    %20zu\n"
+                        " local rcvd (bytes):      %20zu\n"
+                        " dropped ttl (packets):   %20zu\n"
+                        " dropped ttl (bytes):     %20zu\n"
+                        " failed writes (packets): %20zu\n"
+                        " failed writes (bytes):   %20zu\n"
+                        " failed nhop (packets):   %20zu\n"
+                        " failed nhop (bytes):     %20zu\n",
+                        i,
+                        dt.stat[fd].snd_pkt[i],
+                        dt.stat[fd].snd_bytes[i],
+                        dt.stat[fd].rcv_pkt[i],
+                        dt.stat[fd].rcv_bytes[i],
+                        dt.stat[fd].lcl_w_pkt[i],
+                        dt.stat[fd].lcl_w_bytes[i],
+                        dt.stat[fd].lcl_r_pkt[i],
+                        dt.stat[fd].lcl_r_bytes[i],
+                        dt.stat[fd].r_drp_pkt[i],
+                        dt.stat[fd].r_drp_bytes[i],
+                        dt.stat[fd].w_drp_pkt[i],
+                        dt.stat[fd].w_drp_bytes[i],
+                        dt.stat[fd].f_nhp_pkt[i],
+                        dt.stat[fd].f_nhp_bytes[i]
+                        );
+                strcat(buf, str);
+        }
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+
+        return STAT_FILE_LEN;
+#else
+        (void) path;
+        (void) buf;
+        (void) len;
+        return 0;
+#endif
+}
+
+static int dt_stat_readdir(char *** buf)
+{
+#ifdef IPCP_FLOW_STATS
+        char   entry[RIB_PATH_LEN + 1];
+        size_t i;
+        int    idx = 0;
+
+        pthread_rwlock_rdlock(&dt.lock);
+
+        if (dt.n_flows < 1) {
+                pthread_rwlock_unlock(&dt.lock);
+                return 0;
+        }
+
+        *buf = malloc(sizeof(**buf) * dt.n_flows);
+        if (*buf == NULL) {
+                pthread_rwlock_unlock(&dt.lock);
+                return -ENOMEM;
+        }
+
+        for (i = 0; i < PROG_MAX_FLOWS; ++i) {
+                pthread_mutex_lock(&dt.stat[i].lock);
+
+                if (dt.stat[i].stamp == 0) {
+                        pthread_mutex_unlock(&dt.stat[i].lock);
+                        /* Optimization: skip unused res_fds. */
+                        if (i < PROG_RES_FDS)
+                                i = PROG_RES_FDS;
+                        continue;
+                }
+
+                sprintf(entry, "%zu", i);
+
+                (*buf)[idx] = malloc(strlen(entry) + 1);
+                if ((*buf)[idx] == NULL) {
+                        while (idx-- > 0)
+                                free((*buf)[idx]);
+                        free(buf);
+                        pthread_mutex_unlock(&dt.stat[i].lock);
+                        pthread_rwlock_unlock(&dt.lock);
+                        return -ENOMEM;
+                }
+
+                strcpy((*buf)[idx++], entry);
+
+                pthread_mutex_unlock(&dt.stat[i].lock);
+        }
+
+        pthread_rwlock_unlock(&dt.lock);
+
+        assert((size_t) idx == dt.n_flows);
+
+        return idx;
+#else
+        (void) buf;
+        return 0;
+#endif
+}
+
+static int dt_stat_getattr(const char *  path,
+                           struct stat * st)
+{
+#ifdef IPCP_FLOW_STATS
+        int fd;
+
+        fd = atoi(path);
+
+        st->st_mode  = S_IFREG | 0755;
+        st->st_nlink = 1;
+        st->st_uid   = getuid();
+        st->st_gid   = getgid();
+
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt.stat[fd].stamp != -1) {
+                st->st_size  = STAT_FILE_LEN;
+                st->st_mtime = dt.stat[fd].stamp;
+        } else {
+                st->st_size  = 0;
+                st->st_mtime = 0;
+        }
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+#else
+        (void) path;
+        (void) st;
+#endif
+        return 0;
+}
+
+static struct rib_ops r_ops = {
+        .read    = dt_stat_read,
+        .readdir = dt_stat_readdir,
+        .getattr = dt_stat_getattr
+};
+
+#ifdef IPCP_FLOW_STATS
+
+static void stat_used(int      fd,
+                      uint64_t addr)
+{
+        struct timespec now;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        memset(&dt.stat[fd], 0, sizeof(dt.stat[fd]));
+
+        dt.stat[fd].stamp = (addr != INVALID_ADDR) ? now.tv_sec : 0;
+        dt.stat[fd].addr = addr;
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+
+        pthread_rwlock_wrlock(&dt.lock);
+
+        (addr != INVALID_ADDR) ? ++dt.n_flows : --dt.n_flows;
+
+        pthread_rwlock_unlock(&dt.lock);
+}
+#endif
+
+static void handle_event(void *       self,
+                         int          event,
+                         const void * o)
+{
+        struct conn * c;
+
+        (void) self;
+
+        c = (struct conn *) o;
+
+        switch (event) {
+        case NOTIFY_DT_CONN_ADD:
+#ifdef IPCP_FLOW_STATS
+                stat_used(c->flow_info.fd, c->conn_info.addr);
+#endif
+                psched_add(dt.psched, c->flow_info.fd);
+                log_dbg("Added fd %d to packet scheduler.", c->flow_info.fd);
+                break;
+        case NOTIFY_DT_CONN_DEL:
+#ifdef IPCP_FLOW_STATS
+                stat_used(c->flow_info.fd, INVALID_ADDR);
+#endif
+                psched_del(dt.psched, c->flow_info.fd);
+                log_dbg("Removed fd %d from "
+                        "packet scheduler.", c->flow_info.fd);
+                break;
+        default:
+                break;
+        }
+}
+
+static void packet_handler(int                  fd,
+                           qoscube_t            qc,
+                           struct shm_du_buff * sdb)
+{
+        struct dt_pci dt_pci;
+        int           ret;
+        int           ofd;
+#ifdef IPCP_FLOW_STATS
+        size_t        len;
+#else
+        (void)        fd;
+#endif
+
+#ifdef IPCP_FLOW_STATS
+        len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+#endif
+        memset(&dt_pci, 0, sizeof(dt_pci));
+        dt_pci_des(sdb, &dt_pci);
+        if (dt_pci.dst_addr != ipcpi.dt_addr) {
+                if (dt_pci.ttl == 0) {
+                        log_dbg("TTL was zero.");
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+                        ++dt.stat[fd].r_drp_pkt[qc];
+                        dt.stat[fd].r_drp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+                        return;
+                }
+
+                /* FIXME: Use qoscube from PCI instead of incoming flow. */
+                ofd = pff_nhop(dt.pff[qc], dt_pci.dst_addr);
+                if (ofd < 0) {
+                        log_dbg("No next hop for %" PRIu64, dt_pci.dst_addr);
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+                        ++dt.stat[fd].f_nhp_pkt[qc];
+                        dt.stat[fd].f_nhp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+                        return;
+                }
+
+                ret = ipcp_flow_write(ofd, sdb);
+                if (ret < 0) {
+                        log_dbg("Failed to write packet to fd %d.", ofd);
+                        if (ret == -EFLOWDOWN)
+                                notifier_event(NOTIFY_DT_FLOW_DOWN, &ofd);
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+                        pthread_mutex_lock(&dt.stat[ofd].lock);
+
+                        ++dt.stat[ofd].w_drp_pkt[qc];
+                        dt.stat[ofd].w_drp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[ofd].lock);
+#endif
+                        return;
+                }
+#ifdef IPCP_FLOW_STATS
+                pthread_mutex_lock(&dt.stat[fd].lock);
+
+                ++dt.stat[fd].rcv_pkt[qc];
+                dt.stat[fd].rcv_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[fd].lock);
+                pthread_mutex_lock(&dt.stat[ofd].lock);
+
+                ++dt.stat[ofd].snd_pkt[qc];
+                dt.stat[ofd].snd_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[ofd].lock);
+#endif
+        } else {
+                dt_pci_shrink(sdb);
+                if (dt_pci.eid >= PROG_RES_FDS) {
+                        if (ipcp_flow_write(dt_pci.eid, sdb)) {
+                                ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                                pthread_mutex_lock(&dt.stat[fd].lock);
+                                ++dt.stat[fd].rcv_pkt[qc];
+                                dt.stat[fd].rcv_bytes[qc] += len;
+                                pthread_mutex_unlock(&dt.stat[fd].lock);
+
+                                pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+                                ++dt.stat[dt_pci.eid].w_drp_pkt[qc];
+                                dt.stat[dt_pci.eid].w_drp_bytes[qc] += len;
+                                pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+
+                        }
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+                        pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+
+                        ++dt.stat[dt_pci.eid].rcv_pkt[qc];
+                        dt.stat[dt_pci.eid].rcv_bytes[qc] += len;
+                        ++dt.stat[dt_pci.eid].lcl_r_pkt[qc];
+                        dt.stat[dt_pci.eid].lcl_r_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+                        return;
+                }
+
+                if (dt.comps[dt_pci.eid].post_packet == NULL) {
+                        log_err("No registered component on eid %d.",
+                                dt_pci.eid);
+                        ipcp_sdb_release(sdb);
+#ifdef IPCP_FLOW_STATS
+                        pthread_mutex_lock(&dt.stat[fd].lock);
+
+                        ++dt.stat[fd].rcv_pkt[qc];
+                        dt.stat[fd].rcv_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[fd].lock);
+                        pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+
+                        ++dt.stat[dt_pci.eid].w_drp_pkt[qc];
+                        dt.stat[dt_pci.eid].w_drp_bytes[qc] += len;
+
+                        pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+                        return;
+                }
+#ifdef IPCP_FLOW_STATS
+                pthread_mutex_lock(&dt.stat[fd].lock);
+
+                ++dt.stat[fd].rcv_pkt[qc];
+                dt.stat[fd].rcv_bytes[qc] += len;
+                ++dt.stat[fd].lcl_r_pkt[qc];
+                dt.stat[fd].lcl_r_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[fd].lock);
+                pthread_mutex_lock(&dt.stat[dt_pci.eid].lock);
+
+                ++dt.stat[dt_pci.eid].snd_pkt[qc];
+                dt.stat[dt_pci.eid].snd_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[dt_pci.eid].lock);
+#endif
+                dt.comps[dt_pci.eid].post_packet(dt.comps[dt_pci.eid].comp,
+                                                 sdb);
+        }
+}
+
+static void * dt_conn_handle(void * o)
+{
+        struct conn conn;
+
+        (void) o;
+
+        while (true) {
+                if (connmgr_wait(COMPID_DT, &conn)) {
+                        log_err("Failed to get next DT connection.");
+                        continue;
+                }
+
+                /* NOTE: connection acceptance policy could be here. */
+
+                notifier_event(NOTIFY_DT_CONN_ADD, &conn);
+        }
+
+        return 0;
+}
+
+int dt_init(enum pol_routing pr,
+            enum pol_pff     pp,
+            uint8_t          addr_size,
+            uint8_t          eid_size,
+            uint8_t          max_ttl)
+{
+        int              i;
+        int              j;
+        char             dtstr[256];
+        struct conn_info info;
+
+        memset(&info, 0, sizeof(info));
+
+        strcpy(info.comp_name, DT_COMP);
+        strcpy(info.protocol, DT_PROTO);
+        info.pref_version = 1;
+        info.pref_syntax  = PROTO_FIXED;
+        info.addr         = ipcpi.dt_addr;
+
+        dt_pci_info.addr_size = addr_size;
+        dt_pci_info.eid_size  = eid_size;
+        dt_pci_info.max_ttl   = max_ttl;
+
+        dt_pci_info.qc_o      = dt_pci_info.addr_size;
+        dt_pci_info.ttl_o     = dt_pci_info.qc_o + QOS_LEN;
+        dt_pci_info.ecn_o     = dt_pci_info.ttl_o + TTL_LEN;
+        dt_pci_info.eid_o     = dt_pci_info.ecn_o + ECN_LEN;
+        dt_pci_info.head_size = dt_pci_info.eid_o + dt_pci_info.eid_size;
+
+        if (notifier_reg(handle_event, NULL)) {
+                log_err("Failed to register with notifier.");
+                goto fail_notifier_reg;
+        }
+
+        if (connmgr_comp_init(COMPID_DT, &info)) {
+                log_err("Failed to register with connmgr.");
+                goto fail_connmgr_comp_init;
+        }
+
+        if (routing_init(pr)) {
+                log_err("Failed to init routing.");
+                goto fail_routing;
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i) {
+                dt.pff[i] = pff_create(pp);
+                if (dt.pff[i] == NULL) {
+                        log_err("Failed to create a PFF.");
+                        for (j = 0; j < i; ++j)
+                                pff_destroy(dt.pff[j]);
+                        goto fail_pff;
+                }
+        }
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i) {
+                dt.routing[i] = routing_i_create(dt.pff[i]);
+                if (dt.routing[i] == NULL) {
+                        for (j = 0; j < i; ++j)
+                                routing_i_destroy(dt.routing[j]);
+                        goto fail_routing_i;
+                }
+        }
+
+        if (pthread_rwlock_init(&dt.lock, NULL)) {
+                log_err("Failed to init rwlock.");
+                goto fail_rwlock_init;
+        }
+
+        dt.res_fds = bmp_create(PROG_RES_FDS, 0);
+        if (dt.res_fds == NULL)
+                goto fail_res_fds;
+#ifdef IPCP_FLOW_STATS
+        memset(dt.stat, 0, sizeof(dt.stat));
+
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                if (pthread_mutex_init(&dt.stat[i].lock, NULL)) {
+                        for (j = 0; j < i; ++j)
+                                pthread_mutex_destroy(&dt.stat[j].lock);
+                        goto fail_stat_lock;
+                }
+
+        dt.n_flows = 0;
+#endif
+        sprintf(dtstr, "%s.%" PRIu64, DT, ipcpi.dt_addr);
+        if (rib_reg(dtstr, &r_ops))
+                goto fail_rib_reg;
+
+        return 0;
+
+ fail_rib_reg:
+#ifdef IPCP_FLOW_STATS
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                pthread_mutex_destroy(&dt.stat[i].lock);
+ fail_stat_lock:
+#endif
+        bmp_destroy(dt.res_fds);
+ fail_res_fds:
+        pthread_rwlock_destroy(&dt.lock);
+ fail_rwlock_init:
+        for (j = 0; j < QOS_CUBE_MAX; ++j)
+                routing_i_destroy(dt.routing[j]);
+ fail_routing_i:
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                pff_destroy(dt.pff[i]);
+ fail_pff:
+        routing_fini();
+ fail_routing:
+        connmgr_comp_fini(COMPID_DT);
+ fail_connmgr_comp_init:
+        notifier_unreg(&handle_event);
+ fail_notifier_reg:
+        return -1;
+}
+
+void dt_fini(void)
+{
+        int i;
+
+        rib_unreg(DT);
+#ifdef IPCP_FLOW_STATS
+        for (i = 0; i < PROG_MAX_FLOWS; ++i)
+                pthread_mutex_destroy(&dt.stat[i].lock);
+#endif
+        bmp_destroy(dt.res_fds);
+
+        pthread_rwlock_destroy(&dt.lock);
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                routing_i_destroy(dt.routing[i]);
+
+        for (i = 0; i < QOS_CUBE_MAX; ++i)
+                pff_destroy(dt.pff[i]);
+
+        routing_fini();
+
+        connmgr_comp_fini(COMPID_DT);
+
+        notifier_unreg(&handle_event);
+}
+
+int dt_start(void)
+{
+        dt.psched = psched_create(packet_handler);
+        if (dt.psched == NULL) {
+                log_err("Failed to create N-1 packet scheduler.");
+                return -1;
+        }
+
+        if (pthread_create(&dt.listener, NULL, dt_conn_handle, NULL)) {
+                log_err("Failed to create listener thread.");
+                psched_destroy(dt.psched);
+                return -1;
+        }
+
+        return 0;
+}
+
+void dt_stop(void)
+{
+        pthread_cancel(dt.listener);
+        pthread_join(dt.listener, NULL);
+        psched_destroy(dt.psched);
+}
+
+int dt_reg_comp(void * comp,
+                void (* func)(void * func, struct shm_du_buff *),
+                char * name)
+{
+        int res_fd;
+
+        assert(func);
+
+        pthread_rwlock_wrlock(&dt.lock);
+
+        res_fd = bmp_allocate(dt.res_fds);
+        if (!bmp_is_id_valid(dt.res_fds, res_fd)) {
+                log_warn("Reserved fds depleted.");
+                pthread_rwlock_unlock(&dt.lock);
+                return -EBADF;
+        }
+
+        assert(dt.comps[res_fd].post_packet == NULL);
+        assert(dt.comps[res_fd].comp == NULL);
+        assert(dt.comps[res_fd].name == NULL);
+
+        dt.comps[res_fd].post_packet = func;
+        dt.comps[res_fd].comp     = comp;
+        dt.comps[res_fd].name     = name;
+
+        pthread_rwlock_unlock(&dt.lock);
+#ifdef IPCP_FLOW_STATS
+        stat_used(res_fd, ipcpi.dt_addr);
+#endif
+        return res_fd;
+}
+
+int dt_write_packet(uint64_t             dst_addr,
+                    qoscube_t            qc,
+                    int                  np1_fd,
+                    struct shm_du_buff * sdb)
+{
+        int           fd;
+        struct dt_pci dt_pci;
+        int           ret;
+#ifdef IPCP_FLOW_STATS
+        size_t        len;
+#endif
+        assert(sdb);
+        assert(dst_addr != ipcpi.dt_addr);
+
+        fd = pff_nhop(dt.pff[qc], dst_addr);
+        if (fd < 0) {
+                log_dbg("Could not get nhop for addr %" PRIu64 ".", dst_addr);
+#ifdef IPCP_FLOW_STATS
+                len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+
+                pthread_mutex_lock(&dt.stat[np1_fd].lock);
+
+                ++dt.stat[np1_fd].lcl_r_pkt[qc];
+                dt.stat[np1_fd].lcl_r_bytes[qc] += len;
+                ++dt.stat[np1_fd].f_nhp_pkt[qc];
+                dt.stat[np1_fd].f_nhp_bytes[qc] += len;
+
+                pthread_mutex_unlock(&dt.stat[np1_fd].lock);
+#endif
+                return -1;
+        }
+
+        dt_pci.dst_addr = dst_addr;
+        dt_pci.qc       = qc;
+        dt_pci.eid      = np1_fd;
+        dt_pci.ecn      = 0;
+
+        if (dt_pci_ser(sdb, &dt_pci)) {
+                log_dbg("Failed to serialize PDU.");
+#ifdef IPCP_FLOW_STATS
+                len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+#endif
+                goto fail_write;
+        }
+#ifdef IPCP_FLOW_STATS
+        len = shm_du_buff_tail(sdb) - shm_du_buff_head(sdb);
+#endif
+        ret = ipcp_flow_write(fd, sdb);
+        if (ret < 0) {
+                log_dbg("Failed to write packet to fd %d.", fd);
+                if (ret == -EFLOWDOWN)
+                        notifier_event(NOTIFY_DT_FLOW_DOWN, &fd);
+                goto fail_write;
+        }
+#ifdef IPCP_FLOW_STATS
+        pthread_mutex_lock(&dt.stat[np1_fd].lock);
+
+        ++dt.stat[np1_fd].lcl_r_pkt[qc];
+        dt.stat[np1_fd].lcl_r_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[np1_fd].lock);
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt_pci.eid < PROG_RES_FDS) {
+                ++dt.stat[fd].lcl_w_pkt[qc];
+                dt.stat[fd].lcl_w_bytes[qc] += len;
+        }
+        ++dt.stat[fd].snd_pkt[qc];
+        dt.stat[fd].snd_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+        return 0;
+
+ fail_write:
+#ifdef IPCP_FLOW_STATS
+        pthread_mutex_lock(&dt.stat[np1_fd].lock);
+
+        ++dt.stat[np1_fd].lcl_w_pkt[qc];
+        dt.stat[np1_fd].lcl_w_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[np1_fd].lock);
+        pthread_mutex_lock(&dt.stat[fd].lock);
+
+        if (dt_pci.eid < PROG_RES_FDS) {
+                ++dt.stat[fd].lcl_w_pkt[qc];
+                dt.stat[fd].lcl_w_bytes[qc] += len;
+        }
+        ++dt.stat[fd].w_drp_pkt[qc];
+        dt.stat[fd].w_drp_bytes[qc] += len;
+
+        pthread_mutex_unlock(&dt.stat[fd].lock);
+#endif
+        return -1;
+}