openairinterface5g/openair2/LAYER2/PDCP_v10.1.0/pdcp_netlink.c

/*******************************************************************************

  Eurecom OpenAirInterface
  Copyright(c) 1999 - 2013 Eurecom

  This program is free software; you can redistribute it and/or modify it
  under the terms and conditions of the GNU General Public License,
  version 2, as published by the Free Software Foundation.

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  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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  this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

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  the file called "COPYING".

  Contact Information
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/*! \file pdcp_netlink.c
* \brief pdcp communication with linux IP interface,
* have a look at http://man7.org/linux/man-pages/man7/netlink.7.html for netlink.
* Read operation from netlink should be achieved in an asynchronous way to avoid
* subframe overload, netlink congestion...
* \author Sebastien ROUX
* \date 2013
* \version 0.1
* @ingroup pdcp
*/

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <error.h>
#include <unistd.h>

/* Bugfix for version of GCC = 4.4.3 (Ubuntu 10.04) */
#if GCC_VERSION <= 40403
# include <sys/socket.h>
#endif

#include <linux/netlink.h>

#include "assertions.h"
#include "queue.h"
#include "liblfds611.h"

#include "UTIL/LOG/log.h"
#include "UTIL/OCG/OCG.h"
#include "UTIL/OCG/OCG_extern.h"
#include "LAYER2/MAC/extern.h"

#include "pdcp.h"
#include "pdcp_primitives.h"

#define PDCP_QUEUE_NB_ELEMENTS 200

extern char nl_rx_buf[NL_MAX_PAYLOAD];
extern struct nlmsghdr *nas_nlh_rx;
extern struct iovec nas_iov_rx;
extern int nas_sock_fd;
extern struct msghdr nas_msg_rx;

static pthread_t pdcp_netlink_thread;

/* We use lock-free queues between the User-plane driver running in kernel-space
 * and the corresponding entity in User-space.
 * one queue for eNBs (index 0)/one queue for UEs (index 1)
 */
static struct lfds611_queue_state **pdcp_netlink_queue = NULL;
static uint32_t *pdcp_netlink_nb_element = NULL;

static void *pdcp_netlink_thread_fct(void *arg);

int pdcp_netlink_init(void) {

    int i, nb_modules;
    pthread_attr_t attr;
    struct sched_param sched_param;

#if defined(USER_MODE) && defined(OAI_EMU)
    nb_modules = NB_eNB_INST + NB_UE_INST;
#else
    nb_modules = 1;
#endif

    pdcp_netlink_queue = calloc(nb_modules, sizeof(struct lfds611_queue_state*));
    pdcp_netlink_nb_element = malloc(nb_modules * sizeof(uint32_t));

    LOG_I(PDCP, "Creating %d queues for Netlink -> PDCP communication\n",
          nb_modules);

    for (i = 0; i < nb_modules; i++) {
        pdcp_netlink_nb_element[i] = 0;
        if (lfds611_queue_new(&pdcp_netlink_queue[i], PDCP_QUEUE_NB_ELEMENTS) < 0) {
            LOG_E(PDCP, "Failed to create new FIFO for Netlink -> PDCP communcation instance %d\n", i);
            exit(EXIT_FAILURE);
        }
    }

    if (pthread_attr_init(&attr) != 0) {
        LOG_E(PDCP, "Failed to initialize pthread attribute for Netlink -> PDCP communication (%d:%s)\n",
              errno, strerror(errno));
        exit(EXIT_FAILURE);
    }

    sched_param.sched_priority = 10;

    pthread_attr_setschedpolicy(&attr, SCHED_RR);
    pthread_attr_setschedparam(&attr, &sched_param);

    /* Create one thread that fetchs packets from the netlink.
     * When the netlink fifo is full, packets are silently dropped, this behaviour
     * should be avoided if we want a reliable link.
     */
    if (pthread_create(&pdcp_netlink_thread, &attr, pdcp_netlink_thread_fct, NULL) != 0) {
        LOG_E(PDCP, "Failed to create new thread for Netlink/PDCP communcation (%d:%s)\n",
              errno, strerror(errno));
        exit(EXIT_FAILURE);
    }

    return 0;
}

int pdcp_netlink_dequeue_element(uint8_t eNB_flag, uint8_t UE_index, uint8_t eNB_index,
                                 struct pdcp_netlink_element_s **data)
{
    int ret = 0;
    module_id_t module_id;

#if defined(USER_MODE) && defined(OAI_EMU)
    module_id = (eNB_flag != 0) ? eNB_index : NB_eNB_INST + UE_index;
#else
    module_id = 0;
#endif

    ret = lfds611_queue_dequeue(pdcp_netlink_queue[module_id], (void **)data);

    if (ret != 0) {
        LOG_D(PDCP, "De-queueing packet for module %d\n", module_id);
    }
    return ret;
}

static
void *pdcp_netlink_thread_fct(void *arg) {
    int len;
    struct pdcp_netlink_element_s *new_data = NULL;
    uint8_t pdcp_read_state;

    pdcp_read_state = 0;
    memset(nl_rx_buf, 0, NL_MAX_PAYLOAD);

    while (1) {

        len = recvmsg(nas_sock_fd, &nas_msg_rx, 0);

        if (len == 0) {
            /* Other peer (kernel) has performed an orderly shutdown
             */
            LOG_E(PDCP, "Kernel module has closed the netlink\n");
            exit(EXIT_FAILURE);
        } else if (len < 0) {
            /* There was an error */
            LOG_E(PDCP, "An error occured while reading netlink (%d:%s)\n",
                  errno, strerror(errno));
            exit(EXIT_FAILURE);
        } else {
            /* Normal read.
             * NOTE: netlink messages can be assembled to form a multipart message
             */
            for (nas_nlh_rx = (struct nlmsghdr *) nl_rx_buf;
                 NLMSG_OK(nas_nlh_rx, len);
                 nas_nlh_rx = NLMSG_NEXT (nas_nlh_rx, len)) {

                /* There is no need to check for nlmsg_type because
                 * the header is not set in our drivers.
                 */
                if (pdcp_read_state == 0) {
                    new_data = malloc(sizeof(struct pdcp_netlink_element_s));

                    if (nas_nlh_rx->nlmsg_len == sizeof (pdcp_data_req_header_t) + sizeof(struct nlmsghdr)) {
                        pdcp_read_state = 1;
                        memcpy((void *)&new_data->pdcp_read_header, (void *)NLMSG_DATA(nas_nlh_rx), sizeof(pdcp_data_req_header_t));
                        LOG_I(PDCP, "[NETLINK] RX pdcp_data_req_header_t inst %u, "
                              "rb_id %u data_size %d\n",
                              new_data->pdcp_read_header.inst, new_data->pdcp_read_header.rb_id,
                              new_data->pdcp_read_header.data_size);
                    } else {
                        LOG_E(PDCP, "[NETLINK] WRONG size %d should be sizeof "
                              "(pdcp_data_req_header_t) + sizeof(struct nlmsghdr)\n",
                              nas_nlh_rx->nlmsg_len);
                    }
                } else {
                    pdcp_read_state = 0;

#ifdef OAI_EMU
                    if (new_data->pdcp_read_header.inst >= oai_emulation.info.nb_enb_local) {
                        new_data->pdcp_read_header.inst = new_data->pdcp_read_header.inst
                        - oai_emulation.info.nb_enb_local + NB_eNB_INST
                        + oai_emulation.info.first_ue_local;
                    } else {
                        new_data->pdcp_read_header.inst = new_data->pdcp_read_header.inst
                        + oai_emulation.info.first_enb_local;
                    }
#else
                    new_data->pdcp_read_header.inst = 0;
#endif
                    new_data->data = malloc(sizeof(uint8_t) * new_data->pdcp_read_header.data_size);
                    /* Copy the data */
                    memcpy(new_data->data, NLMSG_DATA(nas_nlh_rx), new_data->pdcp_read_header.data_size);

                    if (pdcp_netlink_nb_element[new_data->pdcp_read_header.inst]
                        > PDCP_QUEUE_NB_ELEMENTS) {
                        LOG_E(PDCP, "[Mod %02x] We reached maximum number of elements in pdcp queue (%d)\n",
                              new_data->pdcp_read_header.inst, pdcp_netlink_nb_element);
                    }

                    LOG_D(PDCP, "En-queueing packet for module %d\n", new_data->pdcp_read_header.inst);

                    /* Enqueue the element in the right queue */
//                     lfds611_queue_enqueue(pdcp_netlink_queue[new_data->pdcp_read_header.inst], new_data);
                    lfds611_queue_guaranteed_enqueue(pdcp_netlink_queue[new_data->pdcp_read_header.inst], new_data);
                }
            }
        }
    }
    return NULL;
}