lib, ipcp: Revise fast path and flow interfaces

IPCPs can now use ap_init() to initialize the memory. All flows are
accessed using flow descriptors, this greatly simplifies IPCP
development. Reverts the fast path to a single ap_rbuff per process.
Splits lib/ipcp into irmd/ipcp and lib/ipcp-dev.  Adds a lib/shim-dev
holding tailored functions for shims.  Moves the buffer_t to utils.h.
Fixes the shim-eth-llc length field.  Removes the flow from shared.h.

Fixes #4
Fixes #5

1 files changed, 333 insertions, 645 deletions

diff --git a/src/ipcpd/shim-eth-llc/main.c b/src/ipcpd/shim-eth-llc/main.c
index d74984cc..2cf46e51 100644
--- a/src/ipcpd/shim-eth-llc/main.c
+++ b/src/ipcpd/shim-eth-llc/main.c
@@ -24,24 +24,19 @@
 
 #define _DEFAULT_SOURCE
 
-#include "ipcp.h"
-#include "flow.h"
 #include <ouroboros/errno.h>
-#include <ouroboros/shm_rdrbuff.h>
-#include <ouroboros/shm_ap_rbuff.h>
 #include <ouroboros/list.h>
 #include <ouroboros/utils.h>
-#include <ouroboros/ipcp.h>
-#include <ouroboros/irm_config.h>
-#include <ouroboros/sockets.h>
 #include <ouroboros/bitmap.h>
-#include <ouroboros/flow.h>
 #include <ouroboros/dev.h>
+#include <ouroboros/ipcp-dev.h>
 
 #define OUROBOROS_PREFIX "ipcpd/shim-eth-llc"
 
 #include <ouroboros/logs.h>
 
+#include "ipcp.h"
+
 #include <net/if.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -79,18 +74,12 @@ typedef ShimEthLlcMsg shim_eth_llc_msg_t;
 #define LLC_HEADER_SIZE 3
 #define MAX_SAPS 64
 #define ETH_HEADER_SIZE (2 * MAC_SIZE + 2)
-#define ETH_FRAME_SIZE (SHIM_ETH_LLC_MAX_SDU_SIZE + ETH_HEADER_SIZE +       \
-                        LLC_HEADER_SIZE + 2)
+#define ETH_FRAME_SIZE (ETH_HEADER_SIZE + LLC_HEADER_SIZE \
+                        + SHIM_ETH_LLC_MAX_SDU_SIZE)
 
 /* global for trapping signal */
 int irmd_api;
 
-struct ipcp * _ipcp;
-
-#define shim_data(type) ((struct eth_llc_ipcp_data *) type->data)
-
-#define ipcp_flow(index) ((struct flow *) &(shim_data(_ipcp)->flows[index]))
-
 struct eth_llc_frame {
         uint8_t dst_hwaddr[MAC_SIZE];
         uint8_t src_hwaddr[MAC_SIZE];
@@ -98,196 +87,78 @@ struct eth_llc_frame {
         uint8_t dsap;
         uint8_t ssap;
         uint8_t cf;
-        uint8_t size[2];
         uint8_t payload;
 };
 
-struct eth_llc_flow {
-        struct flow flow;
-        uint8_t     sap;
-        uint8_t     r_sap;
-        uint8_t     r_addr[MAC_SIZE];
+struct ef {
+        int8_t  sap;
+        int8_t  r_sap;
+        uint8_t r_addr[MAC_SIZE];
 };
 
-struct eth_llc_ipcp_data {
-        /* Keep ipcp_data first for polymorphism. */
-        struct ipcp_data      ipcp_data;
-
+struct {
 #ifdef __FreeBSD__
-        struct sockaddr_dl    device;
+        struct sockaddr_dl device;
 #else
-        struct sockaddr_ll    device;
+        struct sockaddr_ll device;
 #endif
-        int                   s_fd;
-
-        struct bmp *          indices;
-        struct bmp *          saps;
+        int                s_fd;
 
-        struct shm_rdrbuff *  rdrb;
-        struct shm_ap_rbuff * rb;
-
-        uint8_t *             rx_ring;
-        uint8_t *             tx_ring;
-        int                   tx_offset;
-
-        struct eth_llc_flow   flows[AP_MAX_FLOWS];
-        pthread_rwlock_t      flows_lock;
+        struct bmp *       saps;
+#if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
+        uint8_t *          rx_ring;
+        uint8_t *          tx_ring;
+        int                tx_offset;
+#endif
+        int *              ef_to_fd;
+        struct ef *        fd_to_ef;
+        pthread_rwlock_t   flows_lock;
 
-        pthread_t             mainloop;
-        pthread_t             sdu_writer;
-        pthread_t             sdu_reader;
-};
+        pthread_t          sdu_writer;
+        pthread_t          sdu_reader;
+} eth_llc_data;
 
-struct eth_llc_ipcp_data * eth_llc_ipcp_data_create()
+static int eth_llc_data_init()
 {
-        struct eth_llc_ipcp_data * eth_llc_data;
-        enum ipcp_type             ipcp_type;
-
-        eth_llc_data = malloc(sizeof(*eth_llc_data));
-        if (eth_llc_data == NULL) {
-                LOG_ERR("Failed to allocate.");
-                return NULL;
-        }
-
-        ipcp_type = THIS_TYPE;
-        if (ipcp_data_init((struct ipcp_data *) eth_llc_data,
-                           ipcp_type) == NULL) {
-                free(eth_llc_data);
-                return NULL;
-        }
-
-        eth_llc_data->rdrb = shm_rdrbuff_open();
-        if (eth_llc_data->rdrb == NULL) {
-                free(eth_llc_data);
-                return NULL;
-        }
-
-        eth_llc_data->rb = shm_ap_rbuff_create_n();
-        if (eth_llc_data->rb == NULL) {
-                shm_rdrbuff_close(eth_llc_data->rdrb);
-                free(eth_llc_data);
-                return NULL;
-        }
+        int i;
 
-        eth_llc_data->indices = bmp_create(AP_MAX_FLOWS, 0);
-        if (eth_llc_data->indices == NULL) {
-                shm_ap_rbuff_destroy(eth_llc_data->rb);
-                shm_rdrbuff_close(eth_llc_data->rdrb);
-                free(eth_llc_data);
-                return NULL;
-        }
+        eth_llc_data.fd_to_ef = malloc(sizeof(struct ef) * IRMD_MAX_FLOWS);
+        if (eth_llc_data.fd_to_ef == NULL)
+                return -ENOMEM;
 
-        eth_llc_data->saps = bmp_create(MAX_SAPS, 2);
-        if (eth_llc_data->indices == NULL) {
-                bmp_destroy(eth_llc_data->indices);
-                shm_ap_rbuff_destroy(eth_llc_data->rb);
-                shm_rdrbuff_close(eth_llc_data->rdrb);
-                free(eth_llc_data);
-                return NULL;
+        eth_llc_data.ef_to_fd = malloc(sizeof(struct ef) * MAX_SAPS);
+        if (eth_llc_data.ef_to_fd == NULL) {
+                free(eth_llc_data.fd_to_ef);
+                return -ENOMEM;
         }
 
-        pthread_rwlock_init(&eth_llc_data->flows_lock, NULL);
-
-        return eth_llc_data;
-}
-
-void eth_llc_ipcp_data_destroy()
-{
-        int i = 0;
-
-        if (_ipcp == NULL)
-                return;
-
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-        if (ipcp_get_state(_ipcp) != IPCP_SHUTDOWN)
-                LOG_WARN("Cleaning up while not in shutdown.");
-
-        /* remove all remaining sdus */
-        while ((i = shm_ap_rbuff_peek_idx(shim_data(_ipcp)->rb)) >= 0)
-                shm_rdrbuff_remove(shim_data(_ipcp)->rdrb, i);
-
-        if (shim_data(_ipcp)->rdrb != NULL)
-                shm_rdrbuff_close(shim_data(_ipcp)->rdrb);
-        if (shim_data(_ipcp)->rb != NULL)
-                shm_ap_rbuff_destroy(shim_data(_ipcp)->rb);
-        if (shim_data(_ipcp)->indices != NULL)
-                bmp_destroy(shim_data(_ipcp)->indices);
-        if (shim_data(_ipcp)->saps != NULL)
-                bmp_destroy(shim_data(_ipcp)->saps);
-
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-
-        for (i = 0; i < AP_MAX_FLOWS; i ++)
-                if (ipcp_flow(i)->rb != NULL)
-                        shm_ap_rbuff_close(ipcp_flow(i)->rb);
-
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        ipcp_data_destroy(_ipcp->data);
-}
-
-/* only call this under flows_lock */
-static int port_id_to_index(int port_id)
-{
-        int i;
-
-        for (i = 0; i < AP_MAX_FLOWS; ++i) {
-                if (ipcp_flow(i)->port_id == port_id
-                    && ipcp_flow(i)->state != FLOW_NULL)
-                        return i;
+        eth_llc_data.saps = bmp_create(MAX_SAPS, 2);
+        if (eth_llc_data.saps == NULL) {
+                free(eth_llc_data.ef_to_fd);
+                free(eth_llc_data.fd_to_ef);
+                return -ENOMEM;
         }
 
-        return -1;
-}
+        for (i = 0; i < MAX_SAPS; ++i)
+                eth_llc_data.ef_to_fd[i] = -1;
 
-/* only call this under flows_lock */
-static int addr_and_saps_to_index(const uint8_t * r_addr,
-                                  uint8_t   r_sap,
-                                  uint8_t   sap)
-{
-        int i = 0;
-
-        for (i = 0; i < AP_MAX_FLOWS; i++) {
-                if (ipcp_flow(i)->state == FLOW_ALLOCATED &&
-                    shim_data(_ipcp)->flows[i].r_sap == r_sap &&
-                    shim_data(_ipcp)->flows[i].sap == sap &&
-                    !memcmp(shim_data(_ipcp)->flows[i].r_addr,
-                            r_addr,
-                            MAC_SIZE)) {
-                        return i;
-                }
+        for (i = 0; i < IRMD_MAX_FLOWS; ++i) {
+                eth_llc_data.fd_to_ef[i].sap   = -1;
+                eth_llc_data.fd_to_ef[i].r_sap = -1;
+                memset(&eth_llc_data.fd_to_ef[i].r_addr, 0, MAC_SIZE);
         }
 
-        return -1;
-}
+        pthread_rwlock_init(&eth_llc_data.flows_lock, NULL);
 
-/* only call this under flows_lock */
-static int sap_to_index(uint8_t sap)
-{
-        int i = 0;
-
-        for (i = 0; i < AP_MAX_FLOWS; i++) {
-                if (shim_data(_ipcp)->flows[i].sap == sap) {
-                        return i;
-                }
-        }
-
-        return -1;
+        return 0;
 }
 
-/* only call this under flows_lock */
-static void destroy_ipcp_flow(int index)
+void eth_llc_data_fini()
 {
-        ipcp_flow(index)->port_id = -1;
-        if (ipcp_flow(index)->rb != NULL)
-                shm_ap_rbuff_close(ipcp_flow(index)->rb);
-        ipcp_flow(index)->rb = NULL;
-        ipcp_flow(index)->state = FLOW_NULL;
-        bmp_release(shim_data(_ipcp)->indices, index);
-        bmp_release(shim_data(_ipcp)->saps,
-                    shim_data(_ipcp)->flows[index].sap);
+        bmp_destroy(eth_llc_data.saps);
+        free(eth_llc_data.fd_to_ef);
+        free(eth_llc_data.ef_to_fd);
+        pthread_rwlock_destroy(&eth_llc_data.flows_lock);
 }
 
 static uint8_t reverse_bits(uint8_t b)
@@ -299,7 +170,7 @@ static uint8_t reverse_bits(uint8_t b)
         return b;
 }
 
-static int eth_llc_ipcp_send_frame(uint8_t   dst_addr[MAC_SIZE],
+static int eth_llc_ipcp_send_frame(uint8_t * dst_addr,
                                    uint8_t   dsap,
                                    uint8_t   ssap,
                                    uint8_t * payload,
@@ -307,24 +178,16 @@ static int eth_llc_ipcp_send_frame(uint8_t   dst_addr[MAC_SIZE],
 {
         int frame_len = 0;
         uint8_t cf = 0x03;
-        int fd;
-
-        uint16_t size;
         uint16_t length;
-
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         struct pollfd pfd;
         struct tpacket_hdr * header;
         uint8_t * frame;
 #else
         uint8_t frame[SHIM_ETH_LLC_MAX_SDU_SIZE];
-#ifdef __FreeBSD__
-        struct sockaddr_dl    device;
-#else
-        struct sockaddr_ll    device;
-#endif
 #endif
         struct eth_llc_frame * llc_frame;
+
         if (payload == NULL) {
                 LOG_ERR("Payload was NULL.");
                 return -1;
@@ -333,79 +196,75 @@ static int eth_llc_ipcp_send_frame(uint8_t   dst_addr[MAC_SIZE],
         if (len > SHIM_ETH_LLC_MAX_SDU_SIZE)
                 return -1;
 
-        fd = (shim_data(_ipcp))->s_fd;
-
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-        header = (void *) shim_data(_ipcp)->tx_ring +
-                (shim_data(_ipcp)->tx_offset * SHM_RDRB_BLOCK_SIZE);
+        header = (void *) (eth_llc_data.tx_ring +
+                           eth_llc_data.tx_offset * SHM_RDRB_BLOCK_SIZE);
 
         while (header->tp_status != TP_STATUS_AVAILABLE) {
-                pfd.fd = fd;
+                pfd.fd = eth_llc_data.s_fd;
                 pfd.revents = 0;
                 pfd.events = POLLIN | POLLRDNORM | POLLERR;
 
                 if (poll(&pfd, 1, -1) <= 0) {
-                        LOG_ERR("Failed to poll: %s.", strerror(errno));
+                        LOG_ERR("Failed to poll.");
                         continue;
                 }
 
-                header = (void *) shim_data(_ipcp)->tx_ring +
-                        (shim_data(_ipcp)->tx_offset * SHM_RDRB_BLOCK_SIZE);
+                header = (void *) (eth_llc_data.tx_ring
+                                   + eth_llc_data.tx_offset
+                                   * SHM_RDRB_BLOCK_SIZE);
         }
 
-        frame = (void *) header + TPACKET_HDRLEN - sizeof(struct sockaddr_ll);
+        frame = (uint8_t *) header
+                + TPACKET_HDRLEN - sizeof(struct sockaddr_ll);
 #endif
-
         llc_frame = (struct eth_llc_frame *) frame;
 
-        memcpy(&llc_frame->dst_hwaddr, dst_addr, MAC_SIZE);
-        memcpy(&llc_frame->src_hwaddr,
+        memcpy(llc_frame->dst_hwaddr, dst_addr, MAC_SIZE);
+        memcpy(llc_frame->src_hwaddr,
 #ifdef __FreeBSD__
-               LLADDR(&shim_data(_ipcp)->device),
+               LLADDR(&eth_llc_data.device),
 #else
-               shim_data(_ipcp)->device.sll_addr,
+               eth_llc_data.device.sll_addr,
 #endif
                MAC_SIZE);
 
-        length = htons(LLC_HEADER_SIZE + sizeof(size) + len);
+        length = htons(LLC_HEADER_SIZE + len);
         memcpy(&llc_frame->length, &length, sizeof(length));
         llc_frame->dsap = dsap;
         llc_frame->ssap = ssap;
-        llc_frame->cf = cf;
-        /* write the payload length, can't trust the driver */
-        size = htons(len);
-        memcpy(&llc_frame->size, &size, sizeof(size));
+        llc_frame->cf   = cf;
         memcpy(&llc_frame->payload, payload, len);
 
-        frame_len = ETH_HEADER_SIZE + LLC_HEADER_SIZE + sizeof(uint16_t) + len;
+        frame_len = ETH_HEADER_SIZE + LLC_HEADER_SIZE + len;
 
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         header->tp_len = frame_len;
         header->tp_status = TP_STATUS_SEND_REQUEST;
 
-        if (send(fd, NULL, 0, MSG_DONTWAIT) < 0) {
+        if (send(eth_llc_data.s_fd, NULL, 0, MSG_DONTWAIT) < 0) {
                 LOG_ERR("Failed to write frame into TX_RING.");
                 return -1;
         }
 
-        shim_data(_ipcp)->tx_offset =
-                (shim_data(_ipcp)->tx_offset + 1)
-                & (SHM_BUFFER_SIZE -1);
+        eth_llc_data.tx_offset =
+                (eth_llc_data.tx_offset + 1) & (SHM_BUFFER_SIZE - 1);
 #else
-        device = (shim_data(_ipcp))->device;
-
-        if (sendto(fd, frame, frame_len, 0,
-                   (struct sockaddr *) &device, sizeof(device)) <= 0) {
+        if (sendto(eth_llc_data.s_fd,
+                   frame,
+                   frame_len,
+                   0,
+                   (struct sockaddr *) &eth_llc_data.device,
+                   sizeof(eth_llc_data.device)) <= 0) {
                 LOG_ERR("Failed to send message.");
                 return -1;
         }
 #endif
-
         return 0;
 }
 
 static int eth_llc_ipcp_send_mgmt_frame(shim_eth_llc_msg_t * msg,
-                                        uint8_t              dst_addr[MAC_SIZE])
+                                        uint8_t *            dst_addr)
 {
         size_t    len;
         uint8_t * buf;
@@ -423,6 +282,7 @@ static int eth_llc_ipcp_send_mgmt_frame(shim_eth_llc_msg_t * msg,
         if (eth_llc_ipcp_send_frame(dst_addr, reverse_bits(MGMT_SAP),
                                     reverse_bits(MGMT_SAP), buf, len)) {
                 LOG_ERR("Failed to send management frame.");
+                free(buf);
                 return -1;
         }
 
@@ -431,10 +291,10 @@ static int eth_llc_ipcp_send_mgmt_frame(shim_eth_llc_msg_t * msg,
         return 0;
 }
 
-static int eth_llc_ipcp_port_alloc(uint8_t dst_addr[MAC_SIZE],
-                                   uint8_t ssap,
-                                   char *  dst_name,
-                                   char *  src_ae_name)
+static int eth_llc_ipcp_sap_alloc(uint8_t * dst_addr,
+                                  uint8_t   ssap,
+                                  char *    dst_name,
+                                  char *    src_ae_name)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
@@ -446,10 +306,10 @@ static int eth_llc_ipcp_port_alloc(uint8_t dst_addr[MAC_SIZE],
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
 
-static int eth_llc_ipcp_port_alloc_resp(uint8_t dst_addr[MAC_SIZE],
-                                        uint8_t ssap,
-                                        uint8_t dsap,
-                                        int     response)
+static int eth_llc_ipcp_sap_alloc_resp(uint8_t * dst_addr,
+                                       uint8_t   ssap,
+                                       uint8_t   dsap,
+                                       int       response)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
@@ -463,8 +323,7 @@ static int eth_llc_ipcp_port_alloc_resp(uint8_t dst_addr[MAC_SIZE],
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
 
-static int eth_llc_ipcp_port_dealloc(uint8_t dst_addr[MAC_SIZE],
-                                     uint8_t ssap)
+static int eth_llc_ipcp_sap_dealloc(uint8_t * dst_addr, uint8_t ssap)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
@@ -474,142 +333,102 @@ static int eth_llc_ipcp_port_dealloc(uint8_t dst_addr[MAC_SIZE],
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
 
-static int eth_llc_ipcp_port_req(uint8_t r_sap,
-                                 uint8_t r_addr[MAC_SIZE],
-                                 char *  dst_name,
-                                 char *  src_ae_name)
+static int eth_llc_ipcp_sap_req(uint8_t   r_sap,
+                                uint8_t * r_addr,
+                                char *    dst_name,
+                                char *    src_ae_name)
 {
-        int port_id;
-        ssize_t index = 0;
-        int i;
+        int fd;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-
-        index = bmp_allocate(shim_data(_ipcp)->indices);
-        if (index < 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                LOG_ERR("Out of free indices.");
-                return -1;
-        }
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
         /* reply to IRM */
-        port_id = ipcp_flow_req_arr(getpid(),
-                                    dst_name,
-                                    src_ae_name);
-
-        if (port_id < 0) {
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                LOG_ERR("Could not get port id from IRMd.");
+        fd = ipcp_flow_req_arr(getpid(), dst_name, src_ae_name);
+        if (fd < 0) {
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_ERR("Could not get new flow from IRMd.");
                 return -1;
         }
 
-        ipcp_flow(index)->port_id = port_id;
-        ipcp_flow(index)->rb      = NULL;
-        ipcp_flow(index)->state   = FLOW_PENDING;
-        shim_data(_ipcp)->flows[index].r_sap = r_sap;
-        for (i = 0; i < MAC_SIZE; i++) {
-                shim_data(_ipcp)->flows[index].r_addr[i] = r_addr[i];
-        }
+        eth_llc_data.fd_to_ef[fd].r_sap = r_sap;
+        memcpy(eth_llc_data.fd_to_ef[fd].r_addr, r_addr, MAC_SIZE);
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("New flow request, port_id %d, remote SAP %d.", port_id, r_sap);
+        LOG_DBG("New flow request, fd %d, remote SAP %d.", fd, r_sap);
 
         return 0;
 }
 
-static int eth_llc_ipcp_port_alloc_reply(uint8_t ssap,
-                                         uint8_t r_addr[MAC_SIZE],
-                                         int     dsap,
-                                         int     response)
+static int eth_llc_ipcp_sap_alloc_reply(uint8_t   ssap,
+                                        uint8_t * r_addr,
+                                        int       dsap,
+                                        int       response)
 {
-        int index = -1;
         int ret = 0;
-        int port_id = -1;
-        int i;
+        int fd = -1;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_rdlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_rdlock(& eth_llc_data.flows_lock);
 
-        index = sap_to_index(ssap);
-        if (index < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        fd = eth_llc_data.ef_to_fd[dsap];
+        if (fd < 0) {
+                pthread_rwlock_unlock(& eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("No flow found with that SAP.");
                 return -1; /* -EFLOWNOTFOUND */
         }
 
-        if (ipcp_flow(index)->state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1; /* -EFLOWNOTPENDING */
-        }
-
-        port_id = ipcp_flow(index)->port_id;
-
         if (response) {
-                destroy_ipcp_flow(index);
+                bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
         } else {
-                ipcp_flow(index)->state = FLOW_ALLOCATED;
-                shim_data(_ipcp)->flows[index].r_sap = dsap;
-                for (i = 0; i < MAC_SIZE; i++) {
-                        shim_data(_ipcp)->flows[index].r_addr[i] = r_addr[i];
-                }
+                eth_llc_data.fd_to_ef[fd].r_sap = ssap;
+                memcpy(eth_llc_data.fd_to_ef[fd].r_addr, r_addr, MAC_SIZE);
         }
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        LOG_DBG("Flow reply, port_id %d, remote SAP %d.", port_id, dsap);
+        LOG_DBG("Flow reply, fd %d, SSAP %d, DSAP %d.", fd, ssap, dsap);
 
-        if ((ret = ipcp_flow_alloc_reply(getpid(),
-                                         port_id,
-                                         response)) < 0) {
-                return -1; /* -EPIPE */
-        }
+        if ((ret = ipcp_flow_alloc_reply(fd, response)) < 0)
+                return -1;
 
         return ret;
 
 }
 
-static int eth_llc_ipcp_flow_dealloc_req(uint8_t ssap,
-                                         uint8_t r_addr[MAC_SIZE])
+static int eth_llc_ipcp_flow_dealloc_req(uint8_t ssap, uint8_t * r_addr)
 {
-        int port_id = -1;
-        int i = 0;
+        int fd = -1;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        i = sap_to_index(ssap);
-        if (i < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        fd = eth_llc_data.ef_to_fd[ssap];
+        if (fd < 0) {
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("No flow found for remote deallocation request.");
                 return 0;
         }
 
-        port_id = ipcp_flow(i)->port_id;
-        destroy_ipcp_flow(i);
+        bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        irm_flow_dealloc(port_id);
+        flow_dealloc(fd);
 
-        LOG_DBG("Flow with port_id %d deallocated.", port_id);
+        LOG_DBG("Flow with fd %d deallocated.", fd);
 
         return 0;
 }
 
-static int eth_llc_ipcp_mgmt_frame(uint8_t * buf,
-                                   size_t    len,
-                                   uint8_t   r_addr[MAC_SIZE])
+static int eth_llc_ipcp_mgmt_frame(uint8_t * buf, size_t len, uint8_t * r_addr)
 {
         shim_eth_llc_msg_t * msg = NULL;
 
@@ -621,27 +440,24 @@ static int eth_llc_ipcp_mgmt_frame(uint8_t * buf,
 
         switch (msg->code) {
         case SHIM_ETH_LLC_MSG_CODE__FLOW_REQ:
-                if (ipcp_data_is_in_registry(_ipcp->data,
-                                             msg->dst_name)) {
-                        eth_llc_ipcp_port_req(msg->ssap,
-                                              r_addr,
-                                              msg->dst_name,
-                                              msg->src_ae_name);
+                if (ipcp_data_is_in_registry(ipcpi.data, msg->dst_name)) {
+                        eth_llc_ipcp_sap_req(msg->ssap,
+                                             r_addr,
+                                             msg->dst_name,
+                                             msg->src_ae_name);
                 }
                 break;
         case SHIM_ETH_LLC_MSG_CODE__FLOW_REPLY:
-                eth_llc_ipcp_port_alloc_reply(msg->ssap,
-                                              r_addr,
-                                              msg->dsap,
-                                              msg->response);
+                eth_llc_ipcp_sap_alloc_reply(msg->ssap,
+                                             r_addr,
+                                             msg->dsap,
+                                             msg->response);
                 break;
         case SHIM_ETH_LLC_MSG_CODE__FLOW_DEALLOC:
-                eth_llc_ipcp_flow_dealloc_req(msg->ssap,
-                                              r_addr);
+                eth_llc_ipcp_flow_dealloc_req(msg->ssap, r_addr);
                 break;
         default:
-                LOG_ERR("Unknown message received %d.",
-                        msg->code);
+                LOG_ERR("Unknown message received %d.", msg->code);
                 shim_eth_llc_msg__free_unpacked(msg, NULL);
                 return -1;
         }
@@ -652,15 +468,11 @@ static int eth_llc_ipcp_mgmt_frame(uint8_t * buf,
 
 static void * eth_llc_ipcp_sdu_reader(void * o)
 {
-        ssize_t index;
-        struct rb_entry e;
         uint8_t br_addr[MAC_SIZE];
+        uint16_t length;
         uint8_t dsap;
         uint8_t ssap;
-        int i = 0;
-        struct eth_llc_frame * llc_frame;
-        uint16_t size;
-
+        int fd;
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         struct pollfd pfd;
         int offset = 0;
@@ -670,43 +482,43 @@ static void * eth_llc_ipcp_sdu_reader(void * o)
         uint8_t buf[ETH_FRAME_SIZE];
         int frame_len = 0;
 #endif
+        struct eth_llc_frame * llc_frame;
 
         memset(br_addr, 0xff, MAC_SIZE * sizeof(uint8_t));
 
         while (true) {
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-                header = (void *) shim_data(_ipcp)->rx_ring +
-                        (offset * SHM_RDRB_BLOCK_SIZE);
+                header = (void *) (eth_llc_data.rx_ring +
+                                   offset * SHM_RDRB_BLOCK_SIZE);
                 while (!(header->tp_status & TP_STATUS_USER)) {
-                        pfd.fd = shim_data(_ipcp)->s_fd;
+                        pfd.fd = eth_llc_data.s_fd;
                         pfd.revents = 0;
                         pfd.events = POLLIN | POLLRDNORM | POLLERR;
 
                         if (poll(&pfd, 1, -1) <= 0) {
-                                LOG_ERR("Failed to poll: %s.", strerror(errno));
+                                LOG_ERR("Failed to poll.");
                                 continue;
                         }
 
-                        header = (void *) shim_data(_ipcp)->rx_ring +
-                                (offset * SHM_RDRB_BLOCK_SIZE);
+                        header = (void *) (eth_llc_data.rx_ring +
+                                           offset * SHM_RDRB_BLOCK_SIZE);
                 }
 
-                buf = (void * ) header + header->tp_mac;
+                buf = (uint8_t * ) header + header->tp_mac;
 #else
-                frame_len = recv(shim_data(_ipcp)->s_fd, buf,
+                frame_len = recv(eth_llc_data.s_fd, buf,
                                  SHIM_ETH_LLC_MAX_SDU_SIZE, 0);
                 if (frame_len < 0) {
-                        LOG_ERR("Failed to recv frame.");
+                        LOG_ERR("Failed to receive frame.");
                         continue;
                 }
 #endif
-
                 llc_frame = (struct eth_llc_frame *) buf;
 
 #ifdef __FreeBSD__
-                if (memcmp(LLADDR(&shim_data(_ipcp)->device),
+                if (memcmp(LLADDR(&eth_llc_data.device),
 #else
-                if (memcmp(shim_data(_ipcp)->device.sll_addr,
+                if (memcmp(eth_llc_data.device.sll_addr,
 #endif
                            &llc_frame->dst_hwaddr,
                            MAC_SIZE) &&
@@ -721,46 +533,29 @@ static void * eth_llc_ipcp_sdu_reader(void * o)
                 dsap = reverse_bits(llc_frame->dsap);
                 ssap = reverse_bits(llc_frame->ssap);
 
-                memcpy(&size, &llc_frame->size, sizeof(size));
+                memcpy(&length, &llc_frame->length, sizeof(length));
+                length = ntohs(length) - LLC_HEADER_SIZE;
 
                 if (ssap == MGMT_SAP && dsap == MGMT_SAP) {
                         eth_llc_ipcp_mgmt_frame(&llc_frame->payload,
-                                                ntohs(size),
+                                                length,
                                                 llc_frame->src_hwaddr);
                 } else {
-                        pthread_rwlock_rdlock(&shim_data(_ipcp)->flows_lock);
-
-                        i = addr_and_saps_to_index(llc_frame->src_hwaddr,
-                                                   ssap,
-                                                   dsap);
-                        if (i < 0) {
-                                pthread_rwlock_unlock(&shim_data(_ipcp)->
-                                                      flows_lock);
+                        pthread_rwlock_rdlock(&eth_llc_data.flows_lock);
+
+                        fd = eth_llc_data.ef_to_fd[dsap];
+                        if (fd < 0) {
+                                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-                                offset = (offset + 1)
-                                        & (SHM_BUFFER_SIZE - 1);
+                                offset = (offset + 1) & (SHM_BUFFER_SIZE - 1);
                                 header->tp_status = TP_STATUS_KERNEL;
 #endif
                                 continue;
                         }
 
-                        while ((index =
-                                shm_rdrbuff_write(shim_data(_ipcp)->rdrb,
-                                                 ipcp_flow(i)->api,
-                                                 0,
-                                                 0,
-                                                 &llc_frame->payload,
-                                                 ntohs(size)))
-                                < 0)
-                                ;
-
-                        e.index = index;
-                        e.port_id = ipcp_flow(i)->port_id;
-
-                        while (shm_ap_rbuff_write(ipcp_flow(i)->rb, &e) < 0)
-                                ;
+                        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
 
-                        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+                        flow_write(fd, &llc_frame->payload, length);
                 }
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
                 offset = (offset + 1) & (SHM_BUFFER_SIZE -1);
@@ -774,51 +569,34 @@ static void * eth_llc_ipcp_sdu_reader(void * o)
 static void * eth_llc_ipcp_sdu_writer(void * o)
 {
         while (true) {
-                struct rb_entry * e;
-                int i;
-                int len = 0;
-                uint8_t * buf;
+                int fd;
+                struct shm_du_buff * sdb;
                 uint8_t ssap;
                 uint8_t dsap;
+                uint8_t r_addr[MAC_SIZE];
 
-                e = shm_ap_rbuff_read(shim_data(_ipcp)->rb);
-                if (e == NULL)
-                        continue;
-
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-
-                len = shm_rdrbuff_read((uint8_t **) &buf,
-                                      shim_data(_ipcp)->rdrb,
-                                      e->index);
-                if (len <= 0) {
-                        free(e);
-                        LOG_ERR("Length of du map read was %d.", len);
-                        continue;
-                }
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-                pthread_rwlock_rdlock(&shim_data(_ipcp)->flows_lock);
-
-                i = port_id_to_index(e->port_id);
-                if (i < 0) {
-                        free(e);
-                        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+                fd = ipcp_flow_read(&sdb);
+                if (fd < 0) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                         continue;
                 }
 
-                ssap = reverse_bits(shim_data(_ipcp)->flows[i].sap);
-                dsap = reverse_bits(shim_data(_ipcp)->flows[i].r_sap);
-
-                eth_llc_ipcp_send_frame(shim_data(_ipcp)->flows[i].r_addr,
-                                        dsap, ssap, buf, len);
-
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+                pthread_rwlock_rdlock(&eth_llc_data.flows_lock);
 
-                if (shim_data(_ipcp)->rdrb != NULL)
-                        shm_rdrbuff_remove(shim_data(_ipcp)->rdrb, e->index);
+                ssap = reverse_bits(eth_llc_data.fd_to_ef[fd].sap);
+                dsap = reverse_bits(eth_llc_data.fd_to_ef[fd].r_sap);
+                memcpy(r_addr, eth_llc_data.fd_to_ef[fd].r_addr, MAC_SIZE);
 
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                free(e);
+                eth_llc_ipcp_send_frame(r_addr, dsap, ssap,
+                                        shm_du_buff_head(sdb),
+                                        shm_du_buff_tail(sdb)
+                                        - shm_du_buff_head(sdb));
+                ipcp_flow_del(sdb);
         }
 
         return (void *) 1;
@@ -826,10 +604,6 @@ static void * eth_llc_ipcp_sdu_writer(void * o)
 
 void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 {
-        sigset_t  sigset;
-        sigemptyset(&sigset);
-        sigaddset(&sigset, SIGINT);
-
         switch(sig) {
         case SIGINT:
         case SIGTERM:
@@ -838,12 +612,11 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
                         LOG_DBG("IPCP %d terminating by order of %d. Bye.",
                                 getpid(), info->si_pid);
 
-                        pthread_rwlock_wrlock(&_ipcp->state_lock);
-
-                        ipcp_set_state(_ipcp, IPCP_SHUTDOWN);
+                        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-                        pthread_rwlock_unlock(&_ipcp->state_lock);
+                        ipcp_set_state(IPCP_SHUTDOWN);
 
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
                 }
         default:
                 return;
@@ -852,7 +625,7 @@ void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
 
 static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 {
-        int fd = -1;
+        int skfd = -1;
         struct ifreq ifr;
         int idx;
 #ifdef __FreeBSD__
@@ -882,17 +655,10 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 
         memset(&ifr, 0, sizeof(ifr));
 
-        fd = socket(AF_UNIX, SOCK_STREAM, 0);
-        if (fd < 0) {
-                LOG_ERR("Failed to open socket.");
-                return -1;
-        }
-
         memcpy(ifr.ifr_name, conf->if_name, strlen(conf->if_name));
 
 #ifdef __FreeBSD__
         if (getifaddrs(&ifaddr) < 0)  {
-                close(fd);
                 LOG_ERR("Could not get interfaces.");
                 return -1;
         }
@@ -900,8 +666,7 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
         for (ifa = ifaddr, idx = 0; ifa != NULL; ifa = ifa->ifa_next, ++idx) {
                 if (strcmp(ifa->ifa_name, conf->if_name))
                         continue;
-                LOG_DBGF("Interface %s found.", conf->if_name);
-
+                LOG_DBG("Interface %s found.", conf->if_name);
                 memcpy(&ifr.ifr_addr, ifa->ifa_addr, sizeof(*ifa->ifa_addr));
                 break;
         }
@@ -913,30 +678,33 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
         }
 
         freeifaddrs(ifaddr);
-
 #else
-        if (ioctl(fd, SIOCGIFHWADDR, &ifr)) {
-                close(fd);
-                LOG_ERR("Failed to ioctl: %s.", strerror(errno));
+        skfd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (skfd < 0) {
+                LOG_ERR("Failed to open socket.");
+                return -1;
+        }
+
+        if (ioctl(skfd, SIOCGIFHWADDR, &ifr)) {
+                LOG_ERR("Failed to ioctl.");
+                close(skfd);
                 return -1;
         }
 
+        close(skfd);
+
         idx = if_nametoindex(conf->if_name);
         if (idx == 0) {
                 LOG_ERR("Failed to retrieve interface index.");
+                close(skfd);
                 return -1;
         }
 #endif
-
-        close(fd);
-
         memset(&(device), 0, sizeof(device));
 #ifdef __FreeBSD__
         device.sdl_index = idx;
         device.sdl_family = AF_LINK;
-        memcpy(LLADDR(&device),
-               ifr.ifr_addr.sa_data,
-               MAC_SIZE * sizeof (uint8_t));
+        memcpy(LLADDR(&device), ifr.ifr_addr.sa_data, MAC_SIZE);
         device.sdl_alen = MAC_SIZE;
         /* TODO: replace socket calls with bpf for BSD */
         LOG_MISSING;
@@ -944,23 +712,21 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 #else
         device.sll_ifindex = idx;
         device.sll_family = AF_PACKET;
-        memcpy(device.sll_addr,
-               ifr.ifr_hwaddr.sa_data,
-               MAC_SIZE * sizeof (uint8_t));
+        memcpy(device.sll_addr, ifr.ifr_hwaddr.sa_data, MAC_SIZE);
         device.sll_halen = MAC_SIZE;
         device.sll_protocol = htons(ETH_P_ALL);
 
-        fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_802_2));
+        skfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_802_2));
 #endif
-        if (fd < 0) {
-                LOG_ERR("Failed to create socket: %s.", strerror(errno));
+        if (skfd < 0) {
+                LOG_ERR("Failed to create socket.");
                 return -1;
         }
 
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
         if (SHIM_ETH_LLC_MAX_SDU_SIZE > SHM_RDRB_BLOCK_SIZE) {
                 LOG_ERR("Max SDU size is bigger than DU map block size.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
@@ -969,68 +735,68 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
         req.tp_block_nr = SHM_BUFFER_SIZE;
         req.tp_frame_nr = SHM_BUFFER_SIZE;
 
-        if (setsockopt(fd, SOL_PACKET, PACKET_RX_RING,
+        if (setsockopt(skfd, SOL_PACKET, PACKET_RX_RING,
                        (void *) &req, sizeof(req))) {
                 LOG_ERR("Failed to set sockopt PACKET_RX_RING");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        if (setsockopt(fd, SOL_PACKET, PACKET_TX_RING,
+        if (setsockopt(skfd, SOL_PACKET, PACKET_TX_RING,
                        (void *) &req, sizeof(req))) {
                 LOG_ERR("Failed to set sockopt PACKET_TX_RING");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 #endif
-
-        if (bind(fd,(struct sockaddr *) &device, sizeof(device))) {
+        if (bind(skfd, (struct sockaddr *) &device, sizeof(device))) {
                 LOG_ERR("Failed to bind socket to interface");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
 #if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
-        shim_data(_ipcp)->rx_ring = mmap(NULL,
-                                         2 * SHM_RDRB_BLOCK_SIZE
-                                         * SHM_BUFFER_SIZE,
-                                         PROT_READ | PROT_WRITE, MAP_SHARED,
-                                         fd, 0);
-        if (shim_data(_ipcp)->rx_ring == NULL) {
+        eth_llc_data.rx_ring = mmap(NULL, 2 * SHM_RDRB_BLOCK_SIZE
+                                    * SHM_BUFFER_SIZE,
+                                    PROT_READ | PROT_WRITE, MAP_SHARED,
+                                    skfd, 0);
+        if (eth_llc_data.rx_ring == NULL) {
                 LOG_ERR("Failed to mmap");
-                close(fd);
+                close(skfd);
                 return -1;
         }
-        shim_data(_ipcp)->tx_ring = shim_data(_ipcp)->rx_ring
-                + (SHM_RDRB_BLOCK_SIZE * SHM_BUFFER_SIZE);
 
+        eth_llc_data.tx_ring = eth_llc_data.rx_ring
+                + SHM_RDRB_BLOCK_SIZE * SHM_BUFFER_SIZE;
 #endif
-        pthread_rwlock_wrlock(&_ipcp->state_lock);
+        pthread_rwlock_wrlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_INIT) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_get_state() != IPCP_INIT) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("IPCP in wrong state.");
-                close(fd);
+                close(skfd);
                 return -1;
         }
 
-        shim_data(_ipcp)->s_fd = fd;
-        shim_data(_ipcp)->device = device;
-        shim_data(_ipcp)->tx_offset = 0;
+        eth_llc_data.s_fd = skfd;
+        eth_llc_data.device = device;
+#if defined(PACKET_RX_RING) && defined(PACKET_TX_RING)
+        eth_llc_data.tx_offset = 0;
+#endif
 
-        ipcp_set_state(_ipcp, IPCP_ENROLLED);
+        ipcp_set_state(IPCP_ENROLLED);
 
-        pthread_create(&shim_data(_ipcp)->sdu_reader,
+        pthread_create(&eth_llc_data.sdu_reader,
                        NULL,
                        eth_llc_ipcp_sdu_reader,
                        NULL);
 
-        pthread_create(&shim_data(_ipcp)->sdu_writer,
+        pthread_create(&eth_llc_data.sdu_writer,
                        NULL,
                        eth_llc_ipcp_sdu_writer,
                        NULL);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         LOG_DBG("Bootstrapped shim IPCP over Ethernet with LLC with api %d.",
                 getpid());
@@ -1040,15 +806,15 @@ static int eth_llc_ipcp_bootstrap(struct dif_config * conf)
 
 static int eth_llc_ipcp_name_reg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(_ipcp->data, name)) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
         }
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         LOG_DBG("Registered %s.", name);
 
@@ -1057,25 +823,22 @@ static int eth_llc_ipcp_name_reg(char * name)
 
 static int eth_llc_ipcp_name_unreg(char * name)
 {
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(_ipcp->data, name);
+        ipcp_data_del_reg_entry(ipcpi.data, name);
 
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
 
-static int eth_llc_ipcp_flow_alloc(pid_t         n_api,
-                                   int           port_id,
+static int eth_llc_ipcp_flow_alloc(int           fd,
                                    char *        dst_name,
                                    char *        src_ae_name,
                                    enum qos_cube qos)
 {
-        struct shm_ap_rbuff * rb;
         uint8_t ssap = 0;
         uint8_t r_addr[MAC_SIZE];
-        int index = 0;
 
         LOG_INFO("Allocating flow to %s.", dst_name);
 
@@ -1083,182 +846,122 @@ static int eth_llc_ipcp_flow_alloc(pid_t         n_api,
                 return -1;
 
         if (qos != QOS_CUBE_BE)
-                LOG_DBGF("QoS requested. Ethernet LLC can't do that. For now.");
-
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL)
-                return -1; /* -ENORBUFF */
+                LOG_DBG("QoS requested. Ethernet LLC can't do that. For now.");
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_get_state(_ipcp) != IPCP_ENROLLED) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                shm_ap_rbuff_close(rb);
-                LOG_DBGF("Won't allocate flow with non-enrolled IPCP.");
+        if (ipcp_get_state() != IPCP_ENROLLED) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_DBG("Won't allocate flow with non-enrolled IPCP.");
                 return -1; /* -ENOTENROLLED */
         }
 
-        index = bmp_allocate(shim_data(_ipcp)->indices);
-        if (index < 0) {
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                shm_ap_rbuff_close(rb);
-                return -1;
-        }
-
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        ssap = bmp_allocate(shim_data(_ipcp)->saps);
+        ssap = bmp_allocate(eth_llc_data.saps);
         if (ssap < 0) {
-                shm_ap_rbuff_close(rb);
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        ipcp_flow(index)->port_id = port_id;
-        ipcp_flow(index)->state = FLOW_PENDING;
-        ipcp_flow(index)->rb = rb;
-        shim_data(_ipcp)->flows[index].sap = ssap;
-
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
-
-        memset(r_addr, 0xff, MAC_SIZE * sizeof(uint8_t));
-
-        if (eth_llc_ipcp_port_alloc(r_addr, ssap,
-                                    dst_name,
-                                    src_ae_name) < 0) {
-                LOG_DBGF("Port alloc returned -1.");
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-                destroy_ipcp_flow(index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        eth_llc_data.fd_to_ef[fd].sap = ssap;
+        eth_llc_data.ef_to_fd[ssap]   = fd;
+
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
+
+        memset(r_addr, 0xff, MAC_SIZE);
+
+        if (eth_llc_ipcp_sap_alloc(r_addr, ssap, dst_name, src_ae_name) < 0) {
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
+                bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
+                eth_llc_data.fd_to_ef[fd].sap = -1;
+                eth_llc_data.ef_to_fd[ssap]   = -1;
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        LOG_DBG("Pending flow with port_id %d on SAP %d.",
-                port_id, ssap);
+        LOG_DBG("Pending flow with fd %d on SAP %d.", fd, ssap);
 
-        return index;
+        return 0;
 }
 
-static int eth_llc_ipcp_flow_alloc_resp(pid_t n_api,
-                                        int   port_id,
-                                        int   response)
+static int eth_llc_ipcp_flow_alloc_resp(int fd, int response)
 {
-        struct shm_ap_rbuff * rb;
-        int index = -1;
         uint8_t ssap = 0;
+        uint8_t r_sap = 0;
+        uint8_t r_addr[MAC_SIZE];
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-
-        index = port_id_to_index(port_id);
-        if (index < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Could not find flow with port_id %d.", port_id);
-                return -1;
-        }
-
-        if (ipcp_flow(index)->state != FLOW_PENDING) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                LOG_DBGF("Flow was not pending.");
-                return -1;
-        }
-
-        rb = shm_ap_rbuff_open_s(n_api);
-        if (rb == NULL) {
-                LOG_ERR("Could not open N + 1 ringbuffer.");
-                ipcp_flow(index)->state = FLOW_NULL;
-                ipcp_flow(index)->port_id = -1;
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return -1;
-        }
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        ssap = bmp_allocate(shim_data(_ipcp)->saps);
+        ssap = bmp_allocate(eth_llc_data.saps);
         if (ssap < 0) {
-                ipcp_flow(index)->state = FLOW_NULL;
-                ipcp_flow(index)->port_id = -1;
-                shm_ap_rbuff_close(ipcp_flow(index)->rb);
-                bmp_release(shim_data(_ipcp)->indices, index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        ipcp_flow(index)->state = FLOW_ALLOCATED;
-        ipcp_flow(index)->rb = rb;
-        shim_data(_ipcp)->flows[index].sap = ssap;
-
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        eth_llc_data.fd_to_ef[fd].sap = ssap;
+        memcpy(r_addr, eth_llc_data.fd_to_ef[fd].r_addr, MAC_SIZE);
+        r_sap = eth_llc_data.fd_to_ef[fd].r_sap;
+        eth_llc_data.ef_to_fd[ssap] = fd;
 
-        if (eth_llc_ipcp_port_alloc_resp(shim_data(_ipcp)->flows[index].r_addr,
-                                         shim_data(_ipcp)->flows[index].r_sap,
-                                         ssap,
-                                         response) < 0) {
-                pthread_rwlock_rdlock(&_ipcp->state_lock);
-                pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
-                destroy_ipcp_flow(index);
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
-                LOG_DBGF("Could not send response.");
+        if (eth_llc_ipcp_sap_alloc_resp(r_addr, ssap, r_sap, response) < 0) {
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+                pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
+                bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
+                pthread_rwlock_unlock(&eth_llc_data.flows_lock);
+                pthread_rwlock_unlock(&ipcpi.state_lock);
                 return -1;
         }
 
-        LOG_DBG("Accepted flow, port_id %d, SAP %d.", port_id, ssap);
+        LOG_DBG("Accepted flow, fd %d, SAP %d.", fd, ssap);
 
         return 0;
 }
 
-static int eth_llc_ipcp_flow_dealloc(int port_id)
+static int eth_llc_ipcp_flow_dealloc(int fd)
 {
-        int index = -1;
         uint8_t sap;
         uint8_t addr[MAC_SIZE];
-        int i;
         int ret;
 
-        pthread_rwlock_rdlock(&_ipcp->state_lock);
-        pthread_rwlock_wrlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+        pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
-        index = port_id_to_index(port_id);
-        if (index < 0) {
-                pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
-                pthread_rwlock_unlock(&_ipcp->state_lock);
-                return 0;
-        }
+        sap = eth_llc_data.fd_to_ef[fd].r_sap;
+        memcpy(addr, eth_llc_data.fd_to_ef[fd].r_addr, MAC_SIZE);
 
-        sap = shim_data(_ipcp)->flows[index].r_sap;
-        for (i = 0; i < MAC_SIZE; i++) {
-                addr[i] = shim_data(_ipcp)->flows[index].r_addr[i];
-        }
+        bmp_release(eth_llc_data.saps, eth_llc_data.fd_to_ef[fd].sap);
+        eth_llc_data.fd_to_ef[fd].sap = -1;
+        eth_llc_data.fd_to_ef[fd].r_sap = -1;
+        memset(&eth_llc_data.fd_to_ef[fd].r_addr, 0, MAC_SIZE);
 
-        destroy_ipcp_flow(index);
+        eth_llc_data.ef_to_fd[sap] = -1;
 
-        pthread_rwlock_unlock(&shim_data(_ipcp)->flows_lock);
+        pthread_rwlock_unlock(&eth_llc_data.flows_lock);
 
-        ret = eth_llc_ipcp_port_dealloc(addr, sap);
-        pthread_rwlock_unlock(&_ipcp->state_lock);
+        ret = eth_llc_ipcp_sap_dealloc(addr, sap);
+        pthread_rwlock_unlock(&ipcpi.state_lock);
 
         if (ret < 0)
-                LOG_DBGF("Could not notify remote.");
+                LOG_DBG("Could not notify remote.");
 
-        LOG_DBG("Flow with port_id %d deallocated.", port_id);
+        LOG_DBG("Flow with fd %d deallocated.", fd);
 
         return 0;
 }
 
 static struct ipcp_ops eth_llc_ops = {
         .ipcp_bootstrap       = eth_llc_ipcp_bootstrap,
-        .ipcp_enroll          = NULL,                       /* shim */
+        .ipcp_enroll          = NULL,
         .ipcp_name_reg        = eth_llc_ipcp_name_reg,
         .ipcp_name_unreg      = eth_llc_ipcp_name_unreg,
         .ipcp_flow_alloc      = eth_llc_ipcp_flow_alloc,
@@ -1270,7 +973,6 @@ int main(int argc, char * argv[])
 {
         struct sigaction sig_act;
         sigset_t  sigset;
-        int i = 0;
 
         sigemptyset(&sigset);
         sigaddset(&sigset, SIGINT);
@@ -1283,6 +985,14 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
+        if (eth_llc_data_init() < 0)
+                exit(EXIT_FAILURE);
+
+        if (ap_init(NULL) < 0) {
+                close_logfile();
+                exit(EXIT_FAILURE);
+        }
+
         /* store the process id of the irmd */
         irmd_api = atoi(argv[1]);
 
@@ -1298,35 +1008,13 @@ int main(int argc, char * argv[])
         sigaction(SIGHUP,  &sig_act, NULL);
         sigaction(SIGPIPE, &sig_act, NULL);
 
-        _ipcp = ipcp_instance_create();
-        if (_ipcp == NULL) {
-                LOG_ERR("Failed to create instance.");
-                close_logfile();
-                exit(EXIT_FAILURE);
-        }
+        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 
-        _ipcp->data = (struct ipcp_data *) eth_llc_ipcp_data_create();
-        if (_ipcp->data == NULL) {
-                LOG_ERR("Failed to create instance data.");
-                free(_ipcp);
+        if (ipcp_init(THIS_TYPE, &eth_llc_ops) < 0) {
                 close_logfile();
                 exit(EXIT_FAILURE);
         }
 
-        for (i = 0; i < AP_MAX_FLOWS; i++) {
-                ipcp_flow(i)->rb = NULL;
-                ipcp_flow(i)->port_id = -1;
-                ipcp_flow(i)->state = FLOW_NULL;
-        }
-
-        _ipcp->ops = &eth_llc_ops;
-        _ipcp->state = IPCP_INIT;
-
-        pthread_sigmask(SIG_BLOCK, &sigset, NULL);
-
-        pthread_create(&shim_data(_ipcp)->mainloop, NULL,
-                       ipcp_main_loop, _ipcp);
-
         pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 
         if (ipcp_create_r(getpid())) {
@@ -1335,17 +1023,17 @@ int main(int argc, char * argv[])
                 exit(EXIT_FAILURE);
         }
 
-        pthread_join(shim_data(_ipcp)->mainloop, NULL);
+        ipcp_fini();
 
-        pthread_cancel(shim_data(_ipcp)->sdu_reader);
-        pthread_cancel(shim_data(_ipcp)->sdu_writer);
+        pthread_cancel(eth_llc_data.sdu_reader);
+        pthread_cancel(eth_llc_data.sdu_writer);
 
-        pthread_join(shim_data(_ipcp)->sdu_writer, NULL);
-        pthread_join(shim_data(_ipcp)->sdu_reader, NULL);
+        pthread_join(eth_llc_data.sdu_writer, NULL);
+        pthread_join(eth_llc_data.sdu_reader, NULL);
 
-        eth_llc_ipcp_data_destroy();
+        ap_fini();
 
-        free(_ipcp);
+        eth_llc_data_fini();
 
         close_logfile();