net/virtio-user: add vhost-user adapter layer
authorJianfeng Tan <jianfeng.tan@intel.com>
Wed, 15 Jun 2016 09:03:22 +0000 (09:03 +0000)
committerYuanhan Liu <yuanhan.liu@linux.intel.com>
Wed, 22 Jun 2016 07:47:12 +0000 (09:47 +0200)
This patch provides vhost adapter layer implementation. Two main
help functions are provided to upper layer (device emulation):
  - vhost_user_setup(), to set up vhost user backend;
  - vhost_user_sock(), to talk with vhost user backend.

  ----------------------
  | ------------------ |
  | | virtio driver  | |
  | ------------------ |
  |         |          |
  | ------------------ | ------>  virtio-user PMD
  | | device emulate | |
  | |                | |
  | | vhost adapter  |-|----> (vhost_user.c)
  | ------------------ |
  ----------------------
            |
            | -------------- --> (vhost-user protocol)
            |
   ------------------
   | vhost backend  |
   ------------------

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
config/common_linuxapp
drivers/net/virtio/Makefile
drivers/net/virtio/virtio_user/vhost.h [new file with mode: 0644]
drivers/net/virtio/virtio_user/vhost_user.c [new file with mode: 0644]

index 7e698e2..2483dfa 100644 (file)
@@ -43,3 +43,4 @@ CONFIG_RTE_LIBRTE_VHOST=y
 CONFIG_RTE_LIBRTE_PMD_VHOST=y
 CONFIG_RTE_LIBRTE_PMD_AF_PACKET=y
 CONFIG_RTE_LIBRTE_POWER=y
+CONFIG_RTE_VIRTIO_USER=y
index ef84f60..c2ed0fa 100644 (file)
@@ -55,6 +55,10 @@ ifeq ($(findstring RTE_MACHINE_CPUFLAG_SSSE3,$(CFLAGS)),RTE_MACHINE_CPUFLAG_SSSE
 SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_rxtx_simple.c
 endif
 
+ifeq ($(CONFIG_RTE_VIRTIO_USER),y)
+SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_user.c
+endif
+
 # this lib depends upon:
 DEPDIRS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += lib/librte_eal lib/librte_ether
 DEPDIRS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += lib/librte_mempool lib/librte_mbuf
diff --git a/drivers/net/virtio/virtio_user/vhost.h b/drivers/net/virtio/virtio_user/vhost.h
new file mode 100644 (file)
index 0000000..4e04ede
--- /dev/null
@@ -0,0 +1,141 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _VHOST_NET_USER_H
+#define _VHOST_NET_USER_H
+
+#include <stdint.h>
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#include "../virtio_pci.h"
+#include "../virtio_logs.h"
+#include "../virtqueue.h"
+
+#define VHOST_MEMORY_MAX_NREGIONS 8
+
+struct vhost_vring_state {
+       unsigned int index;
+       unsigned int num;
+};
+
+struct vhost_vring_file {
+       unsigned int index;
+       int fd;
+};
+
+struct vhost_vring_addr {
+       unsigned int index;
+       /* Option flags. */
+       unsigned int flags;
+       /* Flag values: */
+       /* Whether log address is valid. If set enables logging. */
+#define VHOST_VRING_F_LOG 0
+
+       /* Start of array of descriptors (virtually contiguous) */
+       uint64_t desc_user_addr;
+       /* Used structure address. Must be 32 bit aligned */
+       uint64_t used_user_addr;
+       /* Available structure address. Must be 16 bit aligned */
+       uint64_t avail_user_addr;
+       /* Logging support. */
+       /* Log writes to used structure, at offset calculated from specified
+        * address. Address must be 32 bit aligned.
+        */
+       uint64_t log_guest_addr;
+};
+
+enum vhost_user_request {
+       VHOST_USER_NONE = 0,
+       VHOST_USER_GET_FEATURES = 1,
+       VHOST_USER_SET_FEATURES = 2,
+       VHOST_USER_SET_OWNER = 3,
+       VHOST_USER_RESET_OWNER = 4,
+       VHOST_USER_SET_MEM_TABLE = 5,
+       VHOST_USER_SET_LOG_BASE = 6,
+       VHOST_USER_SET_LOG_FD = 7,
+       VHOST_USER_SET_VRING_NUM = 8,
+       VHOST_USER_SET_VRING_ADDR = 9,
+       VHOST_USER_SET_VRING_BASE = 10,
+       VHOST_USER_GET_VRING_BASE = 11,
+       VHOST_USER_SET_VRING_KICK = 12,
+       VHOST_USER_SET_VRING_CALL = 13,
+       VHOST_USER_SET_VRING_ERR = 14,
+       VHOST_USER_GET_PROTOCOL_FEATURES = 15,
+       VHOST_USER_SET_PROTOCOL_FEATURES = 16,
+       VHOST_USER_GET_QUEUE_NUM = 17,
+       VHOST_USER_SET_VRING_ENABLE = 18,
+       VHOST_USER_MAX
+};
+
+struct vhost_memory_region {
+       uint64_t guest_phys_addr;
+       uint64_t memory_size; /* bytes */
+       uint64_t userspace_addr;
+       uint64_t mmap_offset;
+};
+
+struct vhost_memory {
+       uint32_t nregions;
+       uint32_t padding;
+       struct vhost_memory_region regions[VHOST_MEMORY_MAX_NREGIONS];
+};
+
+struct vhost_user_msg {
+       enum vhost_user_request request;
+
+#define VHOST_USER_VERSION_MASK     0x3
+#define VHOST_USER_REPLY_MASK       (0x1 << 2)
+       uint32_t flags;
+       uint32_t size; /* the following payload size */
+       union {
+#define VHOST_USER_VRING_IDX_MASK   0xff
+#define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
+               uint64_t u64;
+               struct vhost_vring_state state;
+               struct vhost_vring_addr addr;
+               struct vhost_memory memory;
+       } payload;
+       int fds[VHOST_MEMORY_MAX_NREGIONS];
+} __attribute((packed));
+
+#define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
+#define VHOST_USER_PAYLOAD_SIZE \
+       (sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
+
+/* The version of the protocol we support */
+#define VHOST_USER_VERSION    0x1
+
+int vhost_user_sock(int vhostfd, uint64_t req, void *arg);
+int vhost_user_setup(const char *path);
+#endif
diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c
new file mode 100644 (file)
index 0000000..2b34cac
--- /dev/null
@@ -0,0 +1,405 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/un.h>
+#include <string.h>
+#include <errno.h>
+
+#include "vhost.h"
+
+static int
+vhost_user_write(int fd, void *buf, int len, int *fds, int fd_num)
+{
+       int r;
+       struct msghdr msgh;
+       struct iovec iov;
+       size_t fd_size = fd_num * sizeof(int);
+       char control[CMSG_SPACE(fd_size)];
+       struct cmsghdr *cmsg;
+
+       memset(&msgh, 0, sizeof(msgh));
+       memset(control, 0, sizeof(control));
+
+       iov.iov_base = (uint8_t *)buf;
+       iov.iov_len = len;
+
+       msgh.msg_iov = &iov;
+       msgh.msg_iovlen = 1;
+       msgh.msg_control = control;
+       msgh.msg_controllen = sizeof(control);
+
+       cmsg = CMSG_FIRSTHDR(&msgh);
+       cmsg->cmsg_len = CMSG_LEN(fd_size);
+       cmsg->cmsg_level = SOL_SOCKET;
+       cmsg->cmsg_type = SCM_RIGHTS;
+       memcpy(CMSG_DATA(cmsg), fds, fd_size);
+
+       do {
+               r = sendmsg(fd, &msgh, 0);
+       } while (r < 0 && errno == EINTR);
+
+       return r;
+}
+
+static int
+vhost_user_read(int fd, struct vhost_user_msg *msg)
+{
+       uint32_t valid_flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
+       int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
+
+       ret = recv(fd, (void *)msg, sz_hdr, 0);
+       if (ret < sz_hdr) {
+               PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
+                           ret, sz_hdr);
+               goto fail;
+       }
+
+       /* validate msg flags */
+       if (msg->flags != (valid_flags)) {
+               PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
+                           msg->flags, valid_flags);
+               goto fail;
+       }
+
+       sz_payload = msg->size;
+       if (sz_payload) {
+               ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
+               if (ret < sz_payload) {
+                       PMD_DRV_LOG(ERR,
+                               "Failed to recv msg payload: %d instead of %d.",
+                               ret, msg->size);
+                       goto fail;
+               }
+       }
+
+       return 0;
+
+fail:
+       return -1;
+}
+
+struct hugepage_file_info {
+       uint64_t addr;            /**< virtual addr */
+       size_t   size;            /**< the file size */
+       char     path[PATH_MAX];  /**< path to backing file */
+};
+
+/* Two possible options:
+ * 1. Match HUGEPAGE_INFO_FMT to find the file storing struct hugepage_file
+ * array. This is simple but cannot be used in secondary process because
+ * secondary process will close and munmap that file.
+ * 2. Match HUGEFILE_FMT to find hugepage files directly.
+ *
+ * We choose option 2.
+ */
+static int
+get_hugepage_file_info(struct hugepage_file_info huges[], int max)
+{
+       int idx;
+       FILE *f;
+       char buf[BUFSIZ], *tmp, *tail;
+       char *str_underline, *str_start;
+       int huge_index;
+       uint64_t v_start, v_end;
+
+       f = fopen("/proc/self/maps", "r");
+       if (!f) {
+               PMD_DRV_LOG(ERR, "cannot open /proc/self/maps");
+               return -1;
+       }
+
+       idx = 0;
+       while (fgets(buf, sizeof(buf), f) != NULL) {
+               if (sscanf(buf, "%" PRIx64 "-%" PRIx64, &v_start, &v_end) < 2) {
+                       PMD_DRV_LOG(ERR, "Failed to parse address");
+                       goto error;
+               }
+
+               tmp = strchr(buf, ' ') + 1; /** skip address */
+               tmp = strchr(tmp, ' ') + 1; /** skip perm */
+               tmp = strchr(tmp, ' ') + 1; /** skip offset */
+               tmp = strchr(tmp, ' ') + 1; /** skip dev */
+               tmp = strchr(tmp, ' ') + 1; /** skip inode */
+               while (*tmp == ' ')         /** skip spaces */
+                       tmp++;
+               tail = strrchr(tmp, '\n');  /** remove newline if exists */
+               if (tail)
+                       *tail = '\0';
+
+               /* Match HUGEFILE_FMT, aka "%s/%smap_%d",
+                * which is defined in eal_filesystem.h
+                */
+               str_underline = strrchr(tmp, '_');
+               if (!str_underline)
+                       continue;
+
+               str_start = str_underline - strlen("map");
+               if (str_start < tmp)
+                       continue;
+
+               if (sscanf(str_start, "map_%d", &huge_index) != 1)
+                       continue;
+
+               if (idx >= max) {
+                       PMD_DRV_LOG(ERR, "Exceed maximum of %d", max);
+                       goto error;
+               }
+               huges[idx].addr = v_start;
+               huges[idx].size = v_end - v_start;
+               strcpy(huges[idx].path, tmp);
+               idx++;
+       }
+
+       fclose(f);
+       return idx;
+
+error:
+       fclose(f);
+       return -1;
+}
+
+static int
+prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
+{
+       int i, num;
+       struct hugepage_file_info huges[VHOST_MEMORY_MAX_NREGIONS];
+       struct vhost_memory_region *mr;
+
+       num = get_hugepage_file_info(huges, VHOST_MEMORY_MAX_NREGIONS);
+       if (num < 0) {
+               PMD_INIT_LOG(ERR, "Failed to prepare memory for vhost-user");
+               return -1;
+       }
+
+       for (i = 0; i < num; ++i) {
+               mr = &msg->payload.memory.regions[i];
+               mr->guest_phys_addr = huges[i].addr; /* use vaddr! */
+               mr->userspace_addr = huges[i].addr;
+               mr->memory_size = huges[i].size;
+               mr->mmap_offset = 0;
+               fds[i] = open(huges[i].path, O_RDWR);
+       }
+
+       msg->payload.memory.nregions = num;
+       msg->payload.memory.padding = 0;
+
+       return 0;
+}
+
+static struct vhost_user_msg m;
+
+static const char * const vhost_msg_strings[] = {
+       [VHOST_USER_SET_OWNER] = "VHOST_USER_SET_OWNER",
+       [VHOST_USER_RESET_OWNER] = "VHOST_USER_RESET_OWNER",
+       [VHOST_USER_SET_FEATURES] = "VHOST_USER_SET_FEATURES",
+       [VHOST_USER_GET_FEATURES] = "VHOST_USER_GET_FEATURES",
+       [VHOST_USER_SET_VRING_CALL] = "VHOST_USER_SET_VRING_CALL",
+       [VHOST_USER_SET_VRING_NUM] = "VHOST_USER_SET_VRING_NUM",
+       [VHOST_USER_SET_VRING_BASE] = "VHOST_USER_SET_VRING_BASE",
+       [VHOST_USER_GET_VRING_BASE] = "VHOST_USER_GET_VRING_BASE",
+       [VHOST_USER_SET_VRING_ADDR] = "VHOST_USER_SET_VRING_ADDR",
+       [VHOST_USER_SET_VRING_KICK] = "VHOST_USER_SET_VRING_KICK",
+       [VHOST_USER_SET_MEM_TABLE] = "VHOST_USER_SET_MEM_TABLE",
+       NULL,
+};
+
+int
+vhost_user_sock(int vhostfd, uint64_t req, void *arg)
+{
+       struct vhost_user_msg msg;
+       struct vhost_vring_file *file = 0;
+       int need_reply = 0;
+       int fds[VHOST_MEMORY_MAX_NREGIONS];
+       int fd_num = 0;
+       int i, len;
+
+       RTE_SET_USED(m);
+       RTE_SET_USED(vhost_msg_strings);
+
+       PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
+
+       msg.request = req;
+       msg.flags = VHOST_USER_VERSION;
+       msg.size = 0;
+
+       switch (req) {
+       case VHOST_USER_GET_FEATURES:
+               need_reply = 1;
+               break;
+
+       case VHOST_USER_SET_FEATURES:
+       case VHOST_USER_SET_LOG_BASE:
+               msg.payload.u64 = *((__u64 *)arg);
+               msg.size = sizeof(m.payload.u64);
+               break;
+
+       case VHOST_USER_SET_OWNER:
+       case VHOST_USER_RESET_OWNER:
+               break;
+
+       case VHOST_USER_SET_MEM_TABLE:
+               if (prepare_vhost_memory_user(&msg, fds) < 0)
+                       return -1;
+               fd_num = msg.payload.memory.nregions;
+               msg.size = sizeof(m.payload.memory.nregions);
+               msg.size += sizeof(m.payload.memory.padding);
+               msg.size += fd_num * sizeof(struct vhost_memory_region);
+               break;
+
+       case VHOST_USER_SET_LOG_FD:
+               fds[fd_num++] = *((int *)arg);
+               break;
+
+       case VHOST_USER_SET_VRING_NUM:
+       case VHOST_USER_SET_VRING_BASE:
+               memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
+               msg.size = sizeof(m.payload.state);
+               break;
+
+       case VHOST_USER_GET_VRING_BASE:
+               memcpy(&msg.payload.state, arg, sizeof(msg.payload.state));
+               msg.size = sizeof(m.payload.state);
+               need_reply = 1;
+               break;
+
+       case VHOST_USER_SET_VRING_ADDR:
+               memcpy(&msg.payload.addr, arg, sizeof(msg.payload.addr));
+               msg.size = sizeof(m.payload.addr);
+               break;
+
+       case VHOST_USER_SET_VRING_KICK:
+       case VHOST_USER_SET_VRING_CALL:
+       case VHOST_USER_SET_VRING_ERR:
+               file = arg;
+               msg.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK;
+               msg.size = sizeof(m.payload.u64);
+               if (file->fd > 0)
+                       fds[fd_num++] = file->fd;
+               else
+                       msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
+               break;
+
+       default:
+               PMD_DRV_LOG(ERR, "trying to send unhandled msg type");
+               return -1;
+       }
+
+       len = VHOST_USER_HDR_SIZE + msg.size;
+       if (vhost_user_write(vhostfd, &msg, len, fds, fd_num) < 0) {
+               PMD_DRV_LOG(ERR, "%s failed: %s",
+                           vhost_msg_strings[req], strerror(errno));
+               return -1;
+       }
+
+       if (req == VHOST_USER_SET_MEM_TABLE)
+               for (i = 0; i < fd_num; ++i)
+                       close(fds[i]);
+
+       if (need_reply) {
+               if (vhost_user_read(vhostfd, &msg) < 0) {
+                       PMD_DRV_LOG(ERR, "Received msg failed: %s",
+                                   strerror(errno));
+                       return -1;
+               }
+
+               if (req != msg.request) {
+                       PMD_DRV_LOG(ERR, "Received unexpected msg type");
+                       return -1;
+               }
+
+               switch (req) {
+               case VHOST_USER_GET_FEATURES:
+                       if (msg.size != sizeof(m.payload.u64)) {
+                               PMD_DRV_LOG(ERR, "Received bad msg size");
+                               return -1;
+                       }
+                       *((__u64 *)arg) = msg.payload.u64;
+                       break;
+               case VHOST_USER_GET_VRING_BASE:
+                       if (msg.size != sizeof(m.payload.state)) {
+                               PMD_DRV_LOG(ERR, "Received bad msg size");
+                               return -1;
+                       }
+                       memcpy(arg, &msg.payload.state,
+                              sizeof(struct vhost_vring_state));
+                       break;
+               default:
+                       PMD_DRV_LOG(ERR, "Received unexpected msg type");
+                       return -1;
+               }
+       }
+
+       return 0;
+}
+
+/**
+ * Set up environment to talk with a vhost user backend.
+ * @param path
+ *   - The path to vhost user unix socket file.
+ *
+ * @return
+ *   - (-1) if fail to set up;
+ *   - (>=0) if successful, and it is the fd to vhostfd.
+ */
+int
+vhost_user_setup(const char *path)
+{
+       int fd;
+       int flag;
+       struct sockaddr_un un;
+
+       fd = socket(AF_UNIX, SOCK_STREAM, 0);
+       if (fd < 0) {
+               PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
+               return -1;
+       }
+
+       flag = fcntl(fd, F_GETFD);
+       fcntl(fd, F_SETFD, flag | FD_CLOEXEC);
+
+       memset(&un, 0, sizeof(un));
+       un.sun_family = AF_UNIX;
+       snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
+       if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
+               PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
+               close(fd);
+               return -1;
+       }
+
+       return fd;
+}