[PATCH v4 3/3] tools: hv: Add new fcopy application based on uio driver

Saurabh Sengar
2023-08-04T07:10:28Z

Implement the file copy service for Linux guests on Hyper-V. This
permits the host to copy a file (over VMBus) into the guest. This
facility is part of "guest integration services" supported on the
Hyper-V platform.

Here is a link that provides additional details on this functionality:

http://technet.microsoft.com/en-us/library/dn464282.aspx

This new fcopy application uses uio_hv_vmbus_client driver which
makes the earlier hv_util based driver and application obsolete.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
---
[V4]
- Add error check for setting ring_size value in sysfs entry
- Add error handling in fcopy_get_instance_id for instance id not found case

[V3]
- Improve cover commit messages
- Improve debug prints
- Instead of hardcoded instance id, query from class id sysfs
- Set the ring_size value from application
- Update the application to mmap /dev/uio instead of sysfs
- new application compilation dependent on x86

[V2]
- simpler sysfs path

tools/hv/Build | 1 +
tools/hv/Makefile | 10 +-
tools/hv/hv_fcopy_uio_daemon.c | 587 +++++++++++++++++++++++++++++++++
3 files changed, 597 insertions(+), 1 deletion(-)
create mode 100644 tools/hv/hv_fcopy_uio_daemon.c

diff --git a/tools/hv/Build b/tools/hv/Build
index 2a667d3d94cb..efcbb74a0d23 100644
--- a/tools/hv/Build
+++ b/tools/hv/Build
@@ -2,3 +2,4 @@ hv_kvp_daemon-y += hv_kvp_daemon.o
hv_vss_daemon-y += hv_vss_daemon.o
hv_fcopy_daemon-y += hv_fcopy_daemon.o
vmbus_bufring-y += vmbus_bufring.o
+hv_fcopy_uio_daemon-y += hv_fcopy_uio_daemon.o
diff --git a/tools/hv/Makefile b/tools/hv/Makefile
index 33cf488fd20f..678c6c450a53 100644
--- a/tools/hv/Makefile
+++ b/tools/hv/Makefile
@@ -21,8 +21,10 @@ override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include

ifeq ($(SRCARCH),x86)
ALL_LIBS := libvmbus_bufring.a
-endif
+ALL_TARGETS := hv_kvp_daemon hv_vss_daemon hv_fcopy_daemon hv_fcopy_uio_daemon
+else
ALL_TARGETS := hv_kvp_daemon hv_vss_daemon hv_fcopy_daemon
+endif
ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS)) $(patsubst %,$(OUTPUT)%,$(ALL_LIBS))

ALL_SCRIPTS := hv_get_dhcp_info.sh hv_get_dns_info.sh hv_set_ifconfig.sh
@@ -56,6 +58,12 @@ $(HV_FCOPY_DAEMON_IN): FORCE
$(OUTPUT)hv_fcopy_daemon: $(HV_FCOPY_DAEMON_IN)
$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@

+HV_FCOPY_UIO_DAEMON_IN := $(OUTPUT)hv_fcopy_uio_daemon-in.o
+$(HV_FCOPY_UIO_DAEMON_IN): FORCE
+ $(Q)$(MAKE) $(build)=hv_fcopy_uio_daemon
+$(OUTPUT)hv_fcopy_uio_daemon: $(HV_FCOPY_UIO_DAEMON_IN) libvmbus_bufring.a
+ $(QUIET_LINK)$(CC) -lm $< -L. -lvmbus_bufring -o $@
+
clean:
rm -f $(ALL_PROGRAMS)
find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete
diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c
new file mode 100644
index 000000000000..b35737082c91
--- /dev/null
+++ b/tools/hv/hv_fcopy_uio_daemon.c
@@ -0,0 +1,587 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An implementation of host to guest copy functionality for Linux.
+ *
+ * Copyright (C) 2023, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ * Author : Saurabh Sengar <ssengar@microsoft.com>
+ *
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <locale.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <linux/hyperv.h>
+#include "vmbus_bufring.h"
+
+#define ICMSGTYPE_NEGOTIATE 0
+#define ICMSGTYPE_FCOPY 7
+
+#define WIN8_SRV_MAJOR 1
+#define WIN8_SRV_MINOR 1
+#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
+
+#define MAX_PATH_LEN 300
+#define MAX_LINE_LEN 40
+#define DEVICES_SYSFS "/sys/bus/vmbus/devices"
+#define FCOPY_CLASS_ID "34d14be3-dee4-41c8-9ae7-6b174977c192"
+
+#define FCOPY_VER_COUNT 1
+static const int fcopy_versions[] = {
+ WIN8_SRV_VERSION
+};
+
+#define FW_VER_COUNT 1
+static const int fw_versions[] = {
+ UTIL_FW_VERSION
+};
+
+#define HV_RING_SIZE (4 * 4096)
+
+unsigned char desc[HV_RING_SIZE];
+
+static int target_fd;
+static char target_fname[PATH_MAX];
+static unsigned long long filesize;
+
+static int hv_fcopy_create_file(char *file_name, char *path_name, __u32 flags)
+{
+ int error = HV_E_FAIL;
+ char *q, *p;
+
+ filesize = 0;
+ p = (char *)path_name;
+ snprintf(target_fname, sizeof(target_fname), "%s/%s",
+ (char *)path_name, (char *)file_name);
+
+ /*
+ * Check to see if the path is already in place; if not,
+ * create if required.
+ */
+ while ((q = strchr(p, '/')) != NULL) {
+ if (q == p) {
+ p++;
+ continue;
+ }
+ *q = '\0';
+ if (access(path_name, F_OK)) {
+ if (flags & CREATE_PATH) {
+ if (mkdir(path_name, 0755)) {
+ syslog(LOG_ERR, "Failed to create %s",
+ path_name);
+ goto done;
+ }
+ } else {
+ syslog(LOG_ERR, "Invalid path: %s", path_name);
+ goto done;
+ }
+ }
+ p = q + 1;
+ *q = '/';
+ }
+
+ if (!access(target_fname, F_OK)) {
+ syslog(LOG_INFO, "File: %s exists", target_fname);
+ if (!(flags & OVER_WRITE)) {
+ error = HV_ERROR_ALREADY_EXISTS;
+ goto done;
+ }
+ }
+
+ target_fd = open(target_fname,
+ O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0744);
+ if (target_fd == -1) {
+ syslog(LOG_INFO, "Open Failed: %s", strerror(errno));
+ goto done;
+ }
+
+ error = 0;
+done:
+ if (error)
+ target_fname[0] = '\0';
+ return error;
+}
+
+static int hv_copy_data(struct hv_do_fcopy *cpmsg)
+{
+ ssize_t bytes_written;
+ int ret = 0;
+
+ bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
+ cpmsg->offset);
+
+ filesize += cpmsg->size;
+ if (bytes_written != cpmsg->size) {
+ switch (errno) {
+ case ENOSPC:
+ ret = HV_ERROR_DISK_FULL;
+ break;
+ default:
+ ret = HV_E_FAIL;
+ break;
+ }
+ syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
+ filesize, (long)bytes_written, strerror(errno));
+ }
+
+ return ret;
+}
+
+/*
+ * Reset target_fname to "" in the two below functions for hibernation: if
+ * the fcopy operation is aborted by hibernation, the daemon should remove the
+ * partially-copied file; to achieve this, the hv_utils driver always fakes a
+ * CANCEL_FCOPY message upon suspend, and later when the VM resumes back,
+ * the daemon calls hv_copy_cancel() to remove the file; if a file is copied
+ * successfully before suspend, hv_copy_finished() must reset target_fname to
+ * avoid that the file can be incorrectly removed upon resume, since the faked
+ * CANCEL_FCOPY message is spurious in this case.
+ */
+static int hv_copy_finished(void)
+{
+ close(target_fd);
+ target_fname[0] = '\0';
+ return 0;
+}
+
+static void print_usage(char *argv[])
+{
+ fprintf(stderr, "Usage: %s [options]\n"
+ "Options are:\n"
+ " -n, --no-daemon stay in foreground, don't daemonize\n"
+ " -h, --help print this help\n", argv[0]);
+}
+
+static bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, unsigned char *buf,
+ unsigned int buflen, const int *fw_version, int fw_vercnt,
+ const int *srv_version, int srv_vercnt,
+ int *nego_fw_version, int *nego_srv_version)
+{
+ int icframe_major, icframe_minor;
+ int icmsg_major, icmsg_minor;
+ int fw_major, fw_minor;
+ int srv_major, srv_minor;
+ int i, j;
+ bool found_match = false;
+ struct icmsg_negotiate *negop;
+
+ /* Check that there's enough space for icframe_vercnt, icmsg_vercnt */
+ if (buflen < ICMSG_HDR + offsetof(struct icmsg_negotiate, reserved)) {
+ syslog(LOG_ERR, "Invalid icmsg negotiate");
+ return false;
+ }
+
+ icmsghdrp->icmsgsize = 0x10;
+ negop = (struct icmsg_negotiate *)&buf[ICMSG_HDR];
+
+ icframe_major = negop->icframe_vercnt;
+ icframe_minor = 0;
+
+ icmsg_major = negop->icmsg_vercnt;
+ icmsg_minor = 0;
+
+ /* Validate negop packet */
+ if (icframe_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
+ icmsg_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT ||
+ ICMSG_NEGOTIATE_PKT_SIZE(icframe_major, icmsg_major) > buflen) {
+ syslog(LOG_ERR, "Invalid icmsg negotiate - icframe_major: %u, icmsg_major: %u\n",
+ icframe_major, icmsg_major);
+ goto fw_error;
+ }
+
+ /*
+ * Select the framework version number we will
+ * support.
+ */
+
+ for (i = 0; i < fw_vercnt; i++) {
+ fw_major = (fw_version[i] >> 16);
+ fw_minor = (fw_version[i] & 0xFFFF);
+
+ for (j = 0; j < negop->icframe_vercnt; j++) {
+ if (negop->icversion_data[j].major == fw_major &&
+ negop->icversion_data[j].minor == fw_minor) {
+ icframe_major = negop->icversion_data[j].major;
+ icframe_minor = negop->icversion_data[j].minor;
+ found_match = true;
+ break;
+ }
+ }
+
+ if (found_match)
+ break;
+ }
+
+ if (!found_match)
+ goto fw_error;
+
+ found_match = false;
+
+ for (i = 0; i < srv_vercnt; i++) {
+ srv_major = (srv_version[i] >> 16);
+ srv_minor = (srv_version[i] & 0xFFFF);
+
+ for (j = negop->icframe_vercnt;
+ (j < negop->icframe_vercnt + negop->icmsg_vercnt);
+ j++) {
+ if (negop->icversion_data[j].major == srv_major &&
+ negop->icversion_data[j].minor == srv_minor) {
+ icmsg_major = negop->icversion_data[j].major;
+ icmsg_minor = negop->icversion_data[j].minor;
+ found_match = true;
+ break;
+ }
+ }
+
+ if (found_match)
+ break;
+ }
+
+ /*
+ * Respond with the framework and service
+ * version numbers we can support.
+ */
+fw_error:
+ if (!found_match) {
+ negop->icframe_vercnt = 0;
+ negop->icmsg_vercnt = 0;
+ } else {
+ negop->icframe_vercnt = 1;
+ negop->icmsg_vercnt = 1;
+ }
+
+ if (nego_fw_version)
+ *nego_fw_version = (icframe_major << 16) | icframe_minor;
+
+ if (nego_srv_version)
+ *nego_srv_version = (icmsg_major << 16) | icmsg_minor;
+
+ negop->icversion_data[0].major = icframe_major;
+ negop->icversion_data[0].minor = icframe_minor;
+ negop->icversion_data[1].major = icmsg_major;
+ negop->icversion_data[1].minor = icmsg_minor;
+
+ return found_match;
+}
+
+static void wcstoutf8(char *dest, const __u16 *src, size_t dest_size)
+{
+ size_t len = 0;
+
+ while (len < dest_size) {
+ if (src[len] < 0x80)
+ dest[len++] = (char)(*src++);
+ else
+ dest[len++] = 'X';
+ }
+
+ dest[len] = '\0';
+}
+
+static int hv_fcopy_start(struct hv_start_fcopy *smsg_in)
+{
+ setlocale(LC_ALL, "en_US.utf8");
+ size_t file_size, path_size;
+ char *file_name, *path_name;
+ char *in_file_name = (char *)smsg_in->file_name;
+ char *in_path_name = (char *)smsg_in->path_name;
+
+ file_size = wcstombs(NULL, (const wchar_t *restrict)in_file_name, 0) + 1;
+ path_size = wcstombs(NULL, (const wchar_t *restrict)in_path_name, 0) + 1;
+
+ file_name = (char *)malloc(file_size * sizeof(char));
+ path_name = (char *)malloc(path_size * sizeof(char));
+
+ wcstoutf8(file_name, (__u16 *)in_file_name, file_size);
+ wcstoutf8(path_name, (__u16 *)in_path_name, path_size);
+
+ return hv_fcopy_create_file(file_name, path_name, smsg_in->copy_flags);
+}
+
+static int hv_fcopy_send_data(struct hv_fcopy_hdr *fcopy_msg, int recvlen)
+{
+ int operation = fcopy_msg->operation;
+
+ /*
+ * The strings sent from the host are encoded in
+ * utf16; convert it to utf8 strings.
+ * The host assures us that the utf16 strings will not exceed
+ * the max lengths specified. We will however, reserve room
+ * for the string terminating character - in the utf16s_utf8s()
+ * function we limit the size of the buffer where the converted
+ * string is placed to W_MAX_PATH -1 to guarantee
+ * that the strings can be properly terminated!
+ */
+
+ switch (operation) {
+ case START_FILE_COPY:
+ return hv_fcopy_start((struct hv_start_fcopy *)fcopy_msg);
+ case WRITE_TO_FILE:
+ return hv_copy_data((struct hv_do_fcopy *)fcopy_msg);
+ case COMPLETE_FCOPY:
+ return hv_copy_finished();
+ }
+
+ return HV_E_FAIL;
+}
+
+/* process the packet recv from host */
+static int fcopy_pkt_process(struct vmbus_br *txbr)
+{
+ int ret, offset, pktlen;
+ int fcopy_srv_version;
+ const struct vmbus_chanpkt_hdr *pkt;
+ struct hv_fcopy_hdr *fcopy_msg;
+ struct icmsg_hdr *icmsghdr;
+
+ pkt = (const struct vmbus_chanpkt_hdr *)desc;
+ offset = pkt->hlen << 3;
+ pktlen = (pkt->tlen << 3) - offset;
+ icmsghdr = (struct icmsg_hdr *)&desc[offset + sizeof(struct vmbuspipe_hdr)];
+ icmsghdr->status = HV_E_FAIL;
+
+ if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+ if (vmbus_prep_negotiate_resp(icmsghdr, desc + offset, pktlen, fw_versions,
+ FW_VER_COUNT, fcopy_versions, FCOPY_VER_COUNT,
+ NULL, &fcopy_srv_version)) {
+ syslog(LOG_INFO, "FCopy IC version %d.%d",
+ fcopy_srv_version >> 16, fcopy_srv_version & 0xFFFF);
+ icmsghdr->status = 0;
+ }
+ } else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
+ /* Ensure recvlen is big enough to contain hv_fcopy_hdr */
+ if (pktlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
+ syslog(LOG_ERR, "Invalid Fcopy hdr. Packet length too small: %u",
+ pktlen);
+ return -ENOBUFS;
+ }
+
+ fcopy_msg = (struct hv_fcopy_hdr *)&desc[offset + ICMSG_HDR];
+ icmsghdr->status = hv_fcopy_send_data(fcopy_msg, pktlen);
+ }
+
+ icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
+ ret = rte_vmbus_chan_send(txbr, 0x6, desc + offset, pktlen, 0);
+ if (ret) {
+ syslog(LOG_ERR, "Write to ringbuffer failed err: %d", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void fcopy_get_first_folder(char *path, char *chan_no)
+{
+ DIR *dir = opendir(path);
+ struct dirent *entry;
+
+ if (!dir) {
+ syslog(LOG_ERR, "Failed to open directory (errno=%s).\n", strerror(errno));
+ return;
+ }
+
+ while ((entry = readdir(dir)) != NULL) {
+ if (entry->d_type == DT_DIR && strcmp(entry->d_name, ".") != 0 &&
+ strcmp(entry->d_name, "..") != 0) {
+ strcpy(chan_no, entry->d_name);
+ break;
+ }
+ }
+
+ closedir(dir);
+}
+
+static void fcopy_set_ring_size(char *path, char *inst, int size)
+{
+ char ring_size_path[MAX_PATH_LEN] = {0};
+ FILE *fd;
+
+ snprintf(ring_size_path, sizeof(ring_size_path), "%s/%s/%s", path, inst, "ring_size");
+ fd = fopen(ring_size_path, "w");
+ if (!fd) {
+ syslog(LOG_WARNING, "Failed to open ring_size file (errno=%s).\n", strerror(errno));
+ return;
+ }
+
+ setvbuf(fd, NULL, _IONBF, 0); /* don't allow buffering to catch sysfs store error */
+ if (fprintf(fd, "%d", size) < 0)
+ syslog(LOG_WARNING, "Failed to set %d as ring size (errno=%s).\n",
+ size, strerror(errno));
+
+ fclose(fd);
+}
+
+static char *fcopy_read_sysfs(char *path, char *buf, int len)
+{
+ FILE *fd;
+ char *ret;
+
+ fd = fopen(path, "r");
+ if (!fd)
+ return NULL;
+
+ ret = fgets(buf, len, fd);
+ fclose(fd);
+
+ return ret;
+}
+
+static int fcopy_get_instance_id(char *path, char *class_id, char *inst)
+{
+ DIR *dir = opendir(path);
+ struct dirent *entry;
+ char tmp_path[MAX_PATH_LEN] = {0};
+ char line[MAX_LINE_LEN];
+ int ret = -EINVAL;
+
+ if (!dir) {
+ syslog(LOG_ERR, "Failed to open directory (errno=%s).", strerror(errno));
+ return ret;
+ }
+
+ while ((entry = readdir(dir)) != NULL) {
+ if (entry->d_type == DT_LNK && strcmp(entry->d_name, ".") != 0 &&
+ strcmp(entry->d_name, "..") != 0) {
+ /* search for the sysfs path with matching class_id */
+ snprintf(tmp_path, sizeof(tmp_path), "%s/%s/%s",
+ path, entry->d_name, "class_id");
+ if (!fcopy_read_sysfs(tmp_path, line, MAX_LINE_LEN))
+ continue;
+
+ /* class id matches, now fetch the instance id from device_id */
+ if (strstr(line, class_id)) {
+ snprintf(tmp_path, sizeof(tmp_path), "%s/%s/%s",
+ path, entry->d_name, "device_id");
+ if (!fcopy_read_sysfs(tmp_path, line, MAX_LINE_LEN))
+ continue;
+ /* remove braces */
+ strncpy(inst, line + 1, strlen(line) - 3);
+ ret = 0;
+ goto closedir;
+ }
+ }
+ }
+
+ syslog(LOG_ERR, "Failed to fetch instance id");
+closedir:
+ closedir(dir);
+ return ret;
+}
+
+int main(int argc, char *argv[])
+{
+ int fcopy_fd = -1, tmp = 1;
+ int daemonize = 1, long_index = 0, opt, ret = -EINVAL;
+ struct vmbus_br txbr, rxbr;
+ void *ring;
+ uint32_t len = HV_RING_SIZE;
+ char uio_name[10] = {0};
+ char uio_dev_path[15] = {0};
+ char uio_path[MAX_PATH_LEN] = {0};
+ char inst[MAX_LINE_LEN] = {0};
+
+ static struct option long_options[] = {
+ {"help", no_argument, 0, 'h' },
+ {"no-daemon", no_argument, 0, 'n' },
+ {0, 0, 0, 0 }
+ };
+
+ while ((opt = getopt_long(argc, argv, "hn", long_options,
+ &long_index)) != -1) {
+ switch (opt) {
+ case 'n':
+ daemonize = 0;
+ break;
+ case 'h':
+ default:
+ print_usage(argv);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ if (daemonize && daemon(1, 0)) {
+ syslog(LOG_ERR, "daemon() failed; error: %s", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ openlog("HV_UIO_FCOPY", 0, LOG_USER);
+ syslog(LOG_INFO, "starting; pid is:%d", getpid());
+
+ /* get instance id */
+ if (fcopy_get_instance_id(DEVICES_SYSFS, FCOPY_CLASS_ID, inst))
+ exit(EXIT_FAILURE);
+
+ /* set ring_size value */
+ fcopy_set_ring_size(DEVICES_SYSFS, inst, HV_RING_SIZE);
+
+ /* get /dev/uioX dev path and open it */
+ snprintf(uio_path, sizeof(uio_path), "%s/%s/%s", DEVICES_SYSFS, inst, "uio");
+ fcopy_get_first_folder(uio_path, uio_name);
+ snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name);
+ fcopy_fd = open(uio_dev_path, O_RDWR);
+
+ if (fcopy_fd < 0) {
+ syslog(LOG_ERR, "open %s failed; error: %d %s",
+ uio_dev_path, errno, strerror(errno));
+ syslog(LOG_ERR, "Please make sure module uio_hv_vmbus_client is loaded and" \
+ " device is not used by any other application\n");
+ ret = fcopy_fd;
+ exit(EXIT_FAILURE);
+ }
+
+ ring = mmap(NULL, 2 * HV_RING_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fcopy_fd, 0);
+ if (ring == MAP_FAILED) {
+ ret = errno;
+ syslog(LOG_ERR, "mmap ringbuffer failed; error: %d %s", ret, strerror(ret));
+ goto close;
+ }
+ vmbus_br_setup(&txbr, ring, HV_RING_SIZE);
+ vmbus_br_setup(&rxbr, (char *)ring + HV_RING_SIZE, HV_RING_SIZE);
+
+ while (1) {
+ /*
+ * In this loop we process fcopy messages after the
+ * handshake is complete.
+ */
+ ret = pread(fcopy_fd, &tmp, sizeof(int), 0);
+ if (ret < 0) {
+ syslog(LOG_ERR, "pread failed: %s", strerror(errno));
+ continue;
+ }
+
+ len = HV_RING_SIZE;
+ ret = rte_vmbus_chan_recv_raw(&rxbr, desc, &len);
+ if (unlikely(ret <= 0)) {
+ /* This indicates a failure to communicate (or worse) */
+ syslog(LOG_ERR, "VMBus channel recv error: %d", ret);
+ } else {
+ ret = fcopy_pkt_process(&txbr);
+ if (ret < 0)
+ goto close;
+
+ /* Signal host */
+ tmp = 1;
+ if ((write(fcopy_fd, &tmp, sizeof(int))) != sizeof(int)) {
+ ret = errno;
+ syslog(LOG_ERR, "Registration failed: %s\n", strerror(ret));
+ goto close;
+ }
+ }
+ }
+close:
+ close(fcopy_fd);
+ return ret;
+}
--
2.34.1