Merged in dstaesse/ouroboros/be-fast-path (pull request #65)

irmd: flow allocation and fast path

1 files changed, 378 insertions, 146 deletions

diff --git a/src/ipcpd/shim-udp/main.c b/src/ipcpd/shim-udp/main.c
index 460fe9e3..1f7bb12f 100644
--- a/src/ipcpd/shim-udp/main.c
+++ b/src/ipcpd/shim-udp/main.c
@@ -24,12 +24,13 @@
 #include "ipcp.h"
 #include "flow.h"
 #include <ouroboros/shm_du_map.h>
+#include <ouroboros/shm_ap_rbuff.h>
 #include <ouroboros/list.h>
 #include <ouroboros/utils.h>
 #include <ouroboros/ipcp.h>
 #include <ouroboros/dif_config.h>
 #include <ouroboros/sockets.h>
-#include <ouroboros/dev.h>
+#include <ouroboros/bitmap.h>
 
 #define OUROBOROS_PREFIX "ipcpd/shim-udp"
 
@@ -67,6 +68,144 @@ extern struct ipcp * _ipcp; /* defined in test */
 struct ipcp * _ipcp;
 #endif
 
+/*
+ * copied from ouroboros/dev. The shim needs access to the internals
+ * because it doesn't follow all steps necessary steps to get
+ * the info
+ */
+
+#define UNKNOWN_AP "__UNKNOWN_AP__"
+#define UNKNOWN_AE "__UNKNOWN_AE__"
+
+#define AP_MAX_FLOWS 256
+
+#ifndef DU_BUFF_HEADSPACE
+  #define DU_BUFF_HEADSPACE 128
+#endif
+
+#ifndef DU_BUFF_TAILSPACE
+  #define DU_BUFF_TAILSPACE 0
+#endif
+
+/* the shim needs access to these internals */
+struct shim_ap_data {
+        instance_name_t *     api;
+        struct shm_du_map *   dum;
+        struct bmp *          fds;
+
+        struct shm_ap_rbuff * rb;
+        struct flow           flows[AP_MAX_FLOWS];
+
+        pthread_t mainloop;
+        pthread_t sduloop;
+        pthread_t handler;
+        pthread_t sdu_reader[2];
+        int       ping_pong;
+} * _ap_instance;
+
+int shim_ap_init(char * ap_name)
+{
+        _ap_instance = malloc(sizeof(struct shim_ap_data));
+        if (_ap_instance == NULL) {
+                return -1;
+        }
+
+        _ap_instance->api = instance_name_create();
+        if (_ap_instance->api == NULL) {
+                free(_ap_instance);
+                return -1;
+        }
+
+        if (instance_name_init_from(_ap_instance->api,
+                                    ap_name,
+                                    getpid()) == NULL) {
+                instance_name_destroy(_ap_instance->api);
+                free(_ap_instance);
+                return -1;
+        }
+
+        _ap_instance->fds = bmp_create(AP_MAX_FLOWS, 0);
+        if (_ap_instance->fds == NULL) {
+                instance_name_destroy(_ap_instance->api);
+                free(_ap_instance);
+                return -1;
+        }
+
+        _ap_instance->dum = shm_du_map_open();
+        if (_ap_instance->dum == NULL) {
+                instance_name_destroy(_ap_instance->api);
+                bmp_destroy(_ap_instance->fds);
+                free(_ap_instance);
+                return -1;
+        }
+
+        _ap_instance->rb = shm_ap_rbuff_create();
+        if (_ap_instance->rb == NULL) {
+                instance_name_destroy(_ap_instance->api);
+                bmp_destroy(_ap_instance->fds);
+                free(_ap_instance);
+                return -1;
+        }
+
+        return 0;
+}
+
+void shim_ap_fini()
+{
+        int i = 0;
+
+        if (_ap_instance == NULL)
+                return;
+        if (_ap_instance->api != NULL)
+                instance_name_destroy(_ap_instance->api);
+        if (_ap_instance->fds != NULL)
+                bmp_destroy(_ap_instance->fds);
+        if (_ap_instance->dum != NULL)
+                shm_du_map_close(_ap_instance->dum);
+        if (_ap_instance->rb != NULL)
+                shm_ap_rbuff_destroy(_ap_instance->rb);
+        for (i = 0; i < AP_MAX_FLOWS; i ++)
+                if (_ap_instance->flows[i].rb != NULL)
+                        shm_ap_rbuff_close(_ap_instance->flows[i].rb);
+
+        free(_ap_instance);
+}
+
+static int port_id_to_fd(uint32_t port_id)
+{
+        int i;
+        for (i = 0; i < AP_MAX_FLOWS; ++i)
+                if (_ap_instance->flows[i].port_id == port_id
+                        && _ap_instance->flows[i].state != FLOW_NULL)
+                        return i;
+        return -1;
+}
+
+static ssize_t ipcp_udp_flow_write(int fd, void * buf, size_t count)
+{
+        /* the AP chooses the amount of headspace and tailspace */
+        size_t index = shm_create_du_buff(_ap_instance->dum,
+                                          count,
+                                          0,
+                                          buf,
+                                          count);
+        struct rb_entry e = {index, _ap_instance->flows[fd].port_id};
+
+        if (index == -1)
+                return -1;
+
+        if (shm_ap_rbuff_write(_ap_instance->flows[fd].rb, &e) < 0) {
+                shm_release_du_buff(_ap_instance->dum, index);
+                return -EPIPE;
+        }
+
+        return 0;
+}
+
+/*
+ * end copy from dev.c
+ */
+
 struct ipcp_udp_data {
         /* keep ipcp_data first for polymorphism */
         struct ipcp_data ipcp_data;
@@ -79,39 +218,15 @@ struct ipcp_udp_data {
         int                s_fd;
 
         fd_set flow_fd_s;
-        flow_t * fd_to_flow_ptr[FD_SETSIZE];
 
-        pthread_mutex_t   lock;
+        pthread_mutex_t lock;
 };
 
-struct udp_flow {
-        /* keep flow first for polymorphism */
-        flow_t flow;
-        int    fd;
-};
-
-void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
-{
-        switch(sig) {
-        case SIGINT:
-        case SIGTERM:
-        case SIGHUP:
-                LOG_DBG("Terminating by order of %d. Bye.", info->si_pid);
-                if (info->si_pid == irmd_pid) {
-                        /* shm_du_map_close(_ipcp->data->dum); */
-                        exit(0);
-                }
-        default:
-                return;
-        }
-}
-
-struct ipcp_udp_data * ipcp_udp_data_create(char * ap_name)
+struct ipcp_udp_data * ipcp_udp_data_create()
 {
         struct ipcp_udp_data * udp_data;
         struct ipcp_data *     data;
         enum ipcp_type         ipcp_type;
-        int                    n;
 
         udp_data = malloc(sizeof *udp_data);
         if (udp_data == NULL) {
@@ -121,18 +236,52 @@ struct ipcp_udp_data * ipcp_udp_data_create(char * ap_name)
 
         ipcp_type = THIS_TYPE;
         data = (struct ipcp_data *) udp_data;
-        if (ipcp_data_init(data, ap_name, ipcp_type) == NULL) {
+        if (ipcp_data_init(data, ipcp_type) == NULL) {
                 free(udp_data);
                 return NULL;
         }
 
         FD_ZERO(&udp_data->flow_fd_s);
-        for (n = 0; n < FD_SETSIZE; ++n)
-                udp_data->fd_to_flow_ptr[n] = NULL;
 
         return udp_data;
 }
 
+void ipcp_udp_data_destroy(struct ipcp_udp_data * data)
+{
+        if (data == NULL)
+                return;
+
+        ipcp_data_destroy((struct ipcp_data *) data);
+}
+
+void ipcp_udp_destroy(struct ipcp * ipcp)
+{
+        ipcp_udp_data_destroy((struct ipcp_udp_data *) ipcp->data);
+        shim_ap_fini();
+        free(ipcp);
+}
+
+void ipcp_sig_handler(int sig, siginfo_t * info, void * c)
+{
+        switch(sig) {
+        case SIGINT:
+        case SIGTERM:
+        case SIGHUP:
+                if (info->si_pid == irmd_pid || info->si_pid == 0) {
+                        LOG_DBG("Terminating by order of %d. Bye.",
+                                info->si_pid);
+                        pthread_cancel(_ap_instance->mainloop);
+                        pthread_cancel(_ap_instance->handler);
+                        pthread_cancel(_ap_instance->sdu_reader[0]);
+                        pthread_cancel(_ap_instance->sdu_reader[1]);
+                        pthread_cancel(_ap_instance->sduloop);
+                        exit(0);
+                }
+        default:
+                return;
+        }
+}
+
 static void * ipcp_udp_listener()
 {
         char buf[SHIM_UDP_BUF_SIZE];
@@ -141,10 +290,10 @@ static void * ipcp_udp_listener()
         struct sockaddr_in f_saddr;
         struct sockaddr_in c_saddr;
         struct hostent  *  hostp;
-        struct udp_flow *  flow;
         int                sfd = shim_data(_ipcp)->s_fd;
 
         while (true) {
+                int fd;
                 n = sizeof c_saddr;
                 n = recvfrom(sfd, buf, SHIM_UDP_BUF_SIZE, 0,
                              (struct sockaddr *) &c_saddr, (unsigned *) &n);
@@ -157,16 +306,7 @@ static void * ipcp_udp_listener()
                 if (hostp == NULL)
                         continue;
 
-                /* create a new socket for the server */
-                flow = malloc(sizeof *flow);
-                if (flow == NULL)
-                        continue;
-
-                flow->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
-                if (flow->fd == -1) {
-                        free(flow);
-                        continue;
-                }
+                fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
                 memset((char *) &f_saddr, 0, sizeof f_saddr);
                 f_saddr.sin_family      = AF_INET;
@@ -185,36 +325,33 @@ static void * ipcp_udp_listener()
                  * the flow structure
                  */
 
-                if (connect(flow->fd,
+                if (connect(fd,
                             (struct sockaddr *) &c_saddr, sizeof c_saddr) < 0) {
-                        close(flow->fd);
-                        free(flow);
+                        close(fd);
                         continue;
                 }
 
+                /* echo back the packet */
+                while(send(fd, buf, strlen(buf), 0) < 0)
+                        ;
+
                 /* reply to IRM */
 
-                flow->flow.port_id = ipcp_flow_req_arr(getpid(), buf,
-                                                       UNKNOWN_AP, "");
-                if (flow->flow.port_id < 0) {
+                _ap_instance->flows[fd].port_id = ipcp_flow_req_arr(getpid(),
+                                                                    buf,
+                                                                    UNKNOWN_AP,
+                                                                    UNKNOWN_AE);
+                if (_ap_instance->flows[fd].port_id < 0) {
                         LOG_ERR("Could not get port id from IRMd");
-                        close(flow->fd);
-                        free(flow);
+                        close(fd);
                         continue;
                 }
 
-                flow->flow.oflags = FLOW_O_DEFAULT;
-                flow->flow.state  = FLOW_PENDING;
-
-                if(ipcp_data_add_flow(_ipcp->data, (flow_t *) flow)) {
-                        LOG_DBGF("Could not add flow.");
-                        close(flow->fd);
-                        free(flow);
-                        continue;
-                }
+                _ap_instance->flows[fd].rb     = NULL;
+                _ap_instance->flows[fd].state  = FLOW_PENDING;
 
-                FD_SET(flow->fd, &shim_data(_ipcp)->flow_fd_s);
-                shim_data(_ipcp)->fd_to_flow_ptr[flow->fd] = &flow->flow;
+                LOG_DBG("Pending allocation request, port_id %u, UDP fd %d.",
+                         _ap_instance->flows[fd].port_id, fd);
         }
 
         return 0;
@@ -229,8 +366,6 @@ static void * ipcp_udp_sdu_reader()
         struct sockaddr_in r_saddr;
 
         while (true) {
-                flow_t * flow;
-
                 if (select(FD_SETSIZE,
                            &shim_data(_ipcp)->flow_fd_s,
                            NULL, NULL, NULL)
@@ -249,18 +384,8 @@ static void * ipcp_udp_sdu_reader()
                                      (struct sockaddr *) &r_saddr,
                                      (unsigned *) &n);
 
-                        flow = shim_data(_ipcp)->fd_to_flow_ptr[fd];
-                        if (flow->state == FLOW_PENDING) {
-                                if (connect(fd,
-                                            (struct sockaddr *) &r_saddr,
-                                            sizeof r_saddr)
-                                    < 0)
-                                        continue;
-                                flow->state = FLOW_ALLOCATED;
-                        }
-
                         /* send the sdu to the correct port_id */
-                        LOG_MISSING;
+                        ipcp_udp_flow_write(fd, buf, n);
                 }
         }
 
@@ -271,8 +396,6 @@ int ipcp_udp_bootstrap(struct dif_config * conf)
 {
         char ipstr[INET_ADDRSTRLEN];
         char dnsstr[INET_ADDRSTRLEN];
-        pthread_t handler;
-        pthread_t sdu_reader;
         int enable = 1;
 
         if (conf->type != THIS_TYPE) {
@@ -296,7 +419,7 @@ int ipcp_udp_bootstrap(struct dif_config * conf)
                           dnsstr,
                           INET_ADDRSTRLEN);
         else
-                strcpy(dnsstr, "not set.\n");
+                strcpy(dnsstr, "not set");
 
         shim_data(_ipcp)->ip_addr  = conf->ip_addr;
         shim_data(_ipcp)->dns_addr = conf->dns_addr;
@@ -304,7 +427,7 @@ int ipcp_udp_bootstrap(struct dif_config * conf)
         /* UDP listen server */
 
         if ((shim_data(_ipcp)->s_fd =
-             socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
+             socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
                 LOG_DBGF("Can't create socket.");
                 return -1;
         }
@@ -328,13 +451,28 @@ int ipcp_udp_bootstrap(struct dif_config * conf)
                 return -1;
         }
 
-        pthread_create(&handler, NULL, ipcp_udp_listener, NULL);
-        pthread_create(&sdu_reader, NULL, ipcp_udp_sdu_reader, NULL);
+        FD_CLR(shim_data(_ipcp)->s_fd, &shim_data(_ipcp)->flow_fd_s);
+
+        pthread_create(&_ap_instance->handler,
+                       NULL,
+                       ipcp_udp_listener,
+                       NULL);
+        pthread_create(&_ap_instance->sdu_reader[0],
+                       NULL,
+                       ipcp_udp_sdu_reader,
+                       NULL);
+
+        pthread_create(&_ap_instance->sdu_reader[1],
+                       NULL,
+                       ipcp_udp_sdu_reader,
+                       NULL);
+
+        _ap_instance->ping_pong = 0;
 
         _ipcp->state = IPCP_ENROLLED;
 
-        LOG_DBG("Bootstrapped shim IPCP over UDP %s-%d.",
-                _ipcp->data->iname->name, _ipcp->data->iname->id);
+        LOG_DBG("Bootstrapped shim IPCP over UDP with pid %d.",
+                getpid());
 
         LOG_DBG("Bound to IP address %s.", ipstr);
         LOG_DBG("DNS server address is %s.", dnsstr);
@@ -464,23 +602,25 @@ int ipcp_udp_name_unreg(char * name)
 }
 
 int ipcp_udp_flow_alloc(uint32_t          port_id,
+                        pid_t             n_pid,
                         char *            dst_name,
                         char *            src_ap_name,
                         char *            src_ae_name,
                         struct qos_spec * qos)
 {
-        struct udp_flow *  flow = NULL;
         struct sockaddr_in l_saddr;
         struct sockaddr_in r_saddr;
+        struct sockaddr_in rf_saddr;
+        int                fd;
+        int n;
+
+        char * recv_buf = NULL;
 
         struct hostent * h;
 
         if (dst_name == NULL || src_ap_name == NULL || src_ae_name == NULL)
                 return -1;
 
-        LOG_DBG("Received flow allocation request from %s to %s.",
-                src_ap_name, dst_name);
-
         if (strlen(dst_name) > 255
             || strlen(src_ap_name) > 255
             || strlen(src_ae_name) > 255) {
@@ -491,15 +631,7 @@ int ipcp_udp_flow_alloc(uint32_t          port_id,
         if (qos != NULL)
                 LOG_DBGF("QoS requested. UDP/IP can't do that.");
 
-        flow = malloc(sizeof *flow);
-        if (flow == NULL)
-                return -1;
-
-        flow->fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
-        if (flow->fd == -1) {
-                free(flow);
-                return -1;
-        }
+        fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 
         /* this socket is for the flow */
         memset((char *) &l_saddr, 0, sizeof l_saddr);
@@ -507,108 +639,161 @@ int ipcp_udp_flow_alloc(uint32_t          port_id,
         l_saddr.sin_addr.s_addr = local_ip;
         l_saddr.sin_port        = 0;
 
-        if (bind(flow->fd, (struct sockaddr *) &l_saddr, sizeof l_saddr) < 0) {
-                char ipstr[INET_ADDRSTRLEN];
-                inet_ntop(AF_INET,
-                          &l_saddr.sin_addr.s_addr,
-                          ipstr,
-                          INET_ADDRSTRLEN);
-                close(flow->fd);
-                free(flow);
+        if (bind(fd, (struct sockaddr *) &l_saddr, sizeof l_saddr) < 0) {
+                close(fd);
                 return -1;
         }
 
         h = gethostbyname(dst_name);
         if (h == NULL) {
                 LOG_DBGF("Could not resolve %s.", dst_name);
-                close(flow->fd);
-                free(flow);
+                close(fd);
                 return -1;
         }
 
-
         memset((char *) &r_saddr, 0, sizeof r_saddr);
         r_saddr.sin_family      = AF_INET;
-        r_saddr.sin_addr.s_addr = (uint32_t) *(h->h_addr_list[0]);
+        r_saddr.sin_addr.s_addr = *((uint32_t *) (h->h_addr_list[0]));
         r_saddr.sin_port        = LISTEN_PORT;
 
+
         /* at least try to get the packet on the wire */
-        while (sendto(flow->fd, dst_name, strlen(dst_name), 0,
+        while (sendto(fd, dst_name, strlen(dst_name), 0,
                       (struct sockaddr *) &r_saddr, sizeof r_saddr) < 0) {
         }
 
-        flow->flow.port_id = port_id;
-        flow->flow.oflags  = FLOW_O_DEFAULT;
-        flow->flow.state   = FLOW_PENDING;
-
-        /* add flow to the list */
+        /* wait for the other shim IPCP to respond */
 
-        pthread_mutex_lock(&_ipcp->data->flow_lock);
+        recv_buf = malloc(strlen(dst_name) + 1);
+        n = sizeof(rf_saddr);
+        n = recvfrom(fd,
+                     recv_buf,
+                     strlen(dst_name) + 1,
+                     0,
+                     (struct sockaddr *) &rf_saddr,
+                     (unsigned *) &n);
 
-        if(ipcp_data_add_flow(_ipcp->data, (flow_t *) flow)) {
-                LOG_DBGF("Could not add flow.");
-                pthread_mutex_unlock(&_ipcp->data->flow_lock);
-                close(flow->fd);
-                free(flow);
+        if (connect(fd,
+                    (struct sockaddr *) &rf_saddr,
+                    sizeof rf_saddr)
+            < 0) {
+                free(recv_buf);
                 return -1;
         }
 
-        pthread_mutex_unlock(&_ipcp->data->flow_lock);
+        if (!strcmp(recv_buf, dst_name))
+                LOG_WARN("Incorrect echo from server");
+
+        free(recv_buf);
+
+        _ap_instance->flows[fd].port_id = port_id;
+        _ap_instance->flows[fd].state   = FLOW_ALLOCATED;
+        _ap_instance->flows[fd].rb      = shm_ap_rbuff_open(n_pid);
+        if (_ap_instance->flows[fd].rb == NULL) {
+                LOG_ERR("Could not open N + 1 ringbuffer.");
+                close(fd);
+        }
 
         /* tell IRMd that flow allocation "worked" */
 
-        if (ipcp_flow_alloc_reply(getpid(), flow->flow.port_id, 0)) {
+        if (ipcp_flow_alloc_reply(getpid(), port_id, 0)) {
                 LOG_ERR("Failed to notify IRMd about flow allocation reply");
-                close(flow->fd);
-                ipcp_data_del_flow(_ipcp->data, flow->flow.port_id);
+                close(fd);
+                shm_ap_rbuff_close(_ap_instance->flows[fd].rb);
                 return -1;
         }
 
-        FD_SET(flow->fd, &shim_data(_ipcp)->flow_fd_s);
-        shim_data(_ipcp)->fd_to_flow_ptr[flow->fd] = &flow->flow;
+        FD_SET(fd, &shim_data(_ipcp)->flow_fd_s);
 
-        return 0;
+        pthread_cancel(_ap_instance->sdu_reader[_ap_instance->ping_pong]);
+        pthread_create(&_ap_instance->sdu_reader[_ap_instance->ping_pong],
+                       NULL,
+                       ipcp_udp_sdu_reader,
+                       NULL);
+        _ap_instance->ping_pong = !_ap_instance->ping_pong;
+
+        LOG_DBG("Allocated flow with port_id %u on UDP fd %d.", port_id, fd);
+
+        return fd;
 }
 
 int ipcp_udp_flow_alloc_resp(uint32_t port_id,
+                             pid_t    n_pid,
                              int      response)
 {
-        struct udp_flow * flow =
-                (struct udp_flow *) ipcp_data_find_flow(_ipcp->data, port_id);
-        if (flow == NULL) {
-                return -1;
+        int fd = port_id_to_fd(port_id);
+        if (fd < 0) {
+                LOG_DBGF("Could not find flow with port_id %u.", port_id);
+                return 0;
         }
 
-        if (response) {
-                ipcp_data_del_flow(_ipcp->data, port_id);
+        if (response)
                 return 0;
-        }
 
         /* awaken pending flow */
 
-        if (flow->flow.state != FLOW_PENDING)
+        if (_ap_instance->flows[fd].state != FLOW_PENDING) {
+                LOG_DBGF("Flow was not pending.");
                 return -1;
+        }
+
+        _ap_instance->flows[fd].state = FLOW_ALLOCATED;
+        _ap_instance->flows[fd].rb    = shm_ap_rbuff_open(n_pid);
+        if (_ap_instance->flows[fd].rb == NULL) {
+                LOG_ERR("Could not open N + 1 ringbuffer.");
+                _ap_instance->flows[fd].state   = FLOW_NULL;
+                _ap_instance->flows[fd].port_id = 0;
+                return 0;
+        }
 
-        flow->flow.state = FLOW_ALLOCATED;
+        FD_SET(fd, &shim_data(_ipcp)->flow_fd_s);
+
+        pthread_cancel(_ap_instance->sdu_reader[_ap_instance->ping_pong]);
+        pthread_create(&_ap_instance->sdu_reader[_ap_instance->ping_pong],
+                       NULL,
+                       ipcp_udp_sdu_reader,
+                       NULL);
+        _ap_instance->ping_pong = !_ap_instance->ping_pong;
+
+        LOG_DBG("Accepted flow, port_id %u on UDP fd %d.", port_id, fd);
 
         return 0;
 }
 
 int ipcp_udp_flow_dealloc(uint32_t port_id)
 {
-        return 0;
-}
+        int fd = port_id_to_fd(port_id);
+        if (fd < 0) {
+                LOG_DBGF("Could not find flow with port_id %u.", port_id);
+                return 0;
+        }
 
-int ipcp_udp_du_write(uint32_t port_id,
-                      size_t map_index)
-{
+        _ap_instance->flows[fd].state   = FLOW_NULL;
+        _ap_instance->flows[fd].port_id = 0;
+        if (_ap_instance->flows[fd].rb != NULL)
+                shm_ap_rbuff_close(_ap_instance->flows[fd].rb);
+
+        FD_CLR(fd, &shim_data(_ipcp)->flow_fd_s);
         return 0;
 }
 
-int ipcp_udp_du_read(uint32_t port_id,
-                     size_t map_index)
+/* FIXME: may be crap, didn't think this one through */
+int ipcp_udp_flow_dealloc_arr(uint32_t port_id)
 {
-        return 0;
+        int fd = port_id_to_fd(port_id);
+        if (fd < 0) {
+                LOG_DBGF("Could not find flow with port_id %u.", port_id);
+                return 0;
+        }
+
+        _ap_instance->flows[fd].state   = FLOW_NULL;
+        _ap_instance->flows[fd].port_id = 0;
+        if (_ap_instance->flows[fd].rb != NULL)
+                shm_ap_rbuff_close(_ap_instance->flows[fd].rb);
+
+        FD_CLR(fd, &shim_data(_ipcp)->flow_fd_s);
+
+        return ipcp_flow_dealloc(0, port_id);
 }
 
 struct ipcp * ipcp_udp_create(char * ap_name)
@@ -617,11 +802,14 @@ struct ipcp * ipcp_udp_create(char * ap_name)
         struct ipcp_udp_data * data;
         struct ipcp_ops *      ops;
 
+        if (shim_ap_init(ap_name) < 0)
+                return NULL;
+
         i = malloc(sizeof *i);
         if (i == NULL)
                 return NULL;
 
-        data = ipcp_udp_data_create(ap_name);
+        data = ipcp_udp_data_create();
         if (data == NULL) {
                 free(i);
                 return NULL;
@@ -643,8 +831,6 @@ struct ipcp * ipcp_udp_create(char * ap_name)
         ops->ipcp_flow_alloc      = ipcp_udp_flow_alloc;
         ops->ipcp_flow_alloc_resp = ipcp_udp_flow_alloc_resp;
         ops->ipcp_flow_dealloc    = ipcp_udp_flow_dealloc;
-        ops->ipcp_du_read         = ipcp_udp_du_read;
-        ops->ipcp_du_write        = ipcp_udp_du_write;
 
         i->data = (struct ipcp_data *) data;
         i->ops  = ops;
@@ -656,6 +842,40 @@ struct ipcp * ipcp_udp_create(char * ap_name)
 
 #ifndef MAKE_CHECK
 
+/* FIXME: if we move _ap_instance to dev.h, we can reuse it everywhere */
+/* FIXME: stop eating the CPU */
+void * ipcp_udp_sdu_loop(void * o)
+{
+        while (true) {
+                struct rb_entry * e = shm_ap_rbuff_read(_ap_instance->rb);
+                int fd;
+                int len = 0;
+                char * buf;
+                if (e == NULL)
+                        continue;
+
+                len = shm_du_map_read_sdu((uint8_t **) &buf,
+                                          _ap_instance->dum,
+                                          e->index);
+                if (len == -1)
+                        continue;
+
+                fd = port_id_to_fd(e->port_id);
+
+                if (fd == -1)
+                        continue;
+
+                if (len == 0)
+                        continue;
+
+                send(fd, buf, len, 0);
+
+                shm_release_du_buff(_ap_instance->dum, e->index);
+        }
+
+        return (void *) 1;
+}
+
 int main (int argc, char * argv[])
 {
         /* argument 1: pid of irmd ? */
@@ -680,6 +900,7 @@ int main (int argc, char * argv[])
         sigaction(SIGINT,  &sig_act, NULL);
         sigaction(SIGTERM, &sig_act, NULL);
         sigaction(SIGHUP,  &sig_act, NULL);
+        sigaction(SIGPIPE, &sig_act, NULL);
 
         _ipcp = ipcp_udp_create(argv[2]);
         if (_ipcp == NULL) {
@@ -687,7 +908,18 @@ int main (int argc, char * argv[])
                 exit(1);
         }
 
-        ipcp_main_loop(_ipcp);
+        pthread_create(&_ap_instance->mainloop, NULL, ipcp_main_loop, _ipcp);
+        pthread_create(&_ap_instance->sduloop, NULL, ipcp_udp_sdu_loop, NULL);
+
+        pthread_join(_ap_instance->sduloop, NULL);
+        pthread_join(_ap_instance->mainloop, NULL);
+        pthread_join(_ap_instance->handler, NULL);
+        pthread_join(_ap_instance->sdu_reader[0], NULL);
+        pthread_join(_ap_instance->sdu_reader[1], NULL);
+
+        ipcp_udp_destroy(_ipcp);
+
+        shim_ap_fini();
 
         exit(0);
 }