/* * An implementation of key value pair (KVP) functionality for Linux. * * * Copyright (C) 2010, Novell, Inc. * Author : K. Y. Srinivasan * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * KVP protocol: The user mode component first registers with the * the kernel component. Subsequently, the kernel component requests, data * for the specified keys. In response to this message the user mode component * fills in the value corresponding to the specified key. We overload the * sequence field in the cn_msg header to define our KVP message types. * * We use this infrastructure for also supporting queries from user mode * application for state that may be maintained in the KVP kernel component. * */ enum key_index { FullyQualifiedDomainName = 0, IntegrationServicesVersion, /*This key is serviced in the kernel*/ NetworkAddressIPv4, NetworkAddressIPv6, OSBuildNumber, OSName, OSMajorVersion, OSMinorVersion, OSVersion, ProcessorArchitecture }; static char kvp_send_buffer[4096]; static char kvp_recv_buffer[4096 * 2]; static struct sockaddr_nl addr; static int in_hand_shake = 1; static char *os_name = ""; static char *os_major = ""; static char *os_minor = ""; static char *processor_arch; static char *os_build; static char *lic_version = "Unknown version"; static struct utsname uts_buf; #define MAX_FILE_NAME 100 #define ENTRIES_PER_BLOCK 50 struct kvp_record { __u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE]; __u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; }; struct kvp_file_state { int fd; int num_blocks; struct kvp_record *records; int num_records; __u8 fname[MAX_FILE_NAME]; }; static struct kvp_file_state kvp_file_info[KVP_POOL_COUNT]; static void kvp_acquire_lock(int pool) { struct flock fl = {F_WRLCK, SEEK_SET, 0, 0, 0}; fl.l_pid = getpid(); if (fcntl(kvp_file_info[pool].fd, F_SETLKW, &fl) == -1) { syslog(LOG_ERR, "Failed to acquire the lock pool: %d", pool); exit(-1); } } static void kvp_release_lock(int pool) { struct flock fl = {F_UNLCK, SEEK_SET, 0, 0, 0}; fl.l_pid = getpid(); if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) { perror("fcntl"); syslog(LOG_ERR, "Failed to release the lock pool: %d", pool); exit(-1); } } static void kvp_update_file(int pool) { FILE *filep; size_t bytes_written; /* * We are going to write our in-memory registry out to * disk; acquire the lock first. */ kvp_acquire_lock(pool); filep = fopen(kvp_file_info[pool].fname, "w"); if (!filep) { kvp_release_lock(pool); syslog(LOG_ERR, "Failed to open file, pool: %d", pool); exit(-1); } bytes_written = fwrite(kvp_file_info[pool].records, sizeof(struct kvp_record), kvp_file_info[pool].num_records, filep); fflush(filep); kvp_release_lock(pool); } static void kvp_update_mem_state(int pool) { FILE *filep; size_t records_read = 0; struct kvp_record *record = kvp_file_info[pool].records; struct kvp_record *readp; int num_blocks = kvp_file_info[pool].num_blocks; int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK; kvp_acquire_lock(pool); filep = fopen(kvp_file_info[pool].fname, "r"); if (!filep) { kvp_release_lock(pool); syslog(LOG_ERR, "Failed to open file, pool: %d", pool); exit(-1); } while (!feof(filep)) { readp = &record[records_read]; records_read += fread(readp, sizeof(struct kvp_record), ENTRIES_PER_BLOCK * num_blocks, filep); if (!feof(filep)) { /* * We have more data to read. */ num_blocks++; record = realloc(record, alloc_unit * num_blocks); if (record == NULL) { syslog(LOG_ERR, "malloc failed"); exit(-1); } continue; } break; } kvp_file_info[pool].num_blocks = num_blocks; kvp_file_info[pool].records = record; kvp_file_info[pool].num_records = records_read; kvp_release_lock(pool); } static int kvp_file_init(void) { int fd; FILE *filep; size_t records_read; __u8 *fname; struct kvp_record *record; struct kvp_record *readp; int num_blocks; int i; int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK; if (access("/var/opt/hyperv", F_OK)) { if (mkdir("/var/opt/hyperv", S_IRUSR | S_IWUSR | S_IROTH)) { syslog(LOG_ERR, " Failed to create /var/opt/hyperv"); exit(-1); } } for (i = 0; i < KVP_POOL_COUNT; i++) { fname = kvp_file_info[i].fname; records_read = 0; num_blocks = 1; sprintf(fname, "/var/opt/hyperv/.kvp_pool_%d", i); fd = open(fname, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IROTH); if (fd == -1) return 1; filep = fopen(fname, "r"); if (!filep) return 1; record = malloc(alloc_unit * num_blocks); if (record == NULL) { fclose(filep); return 1; } while (!feof(filep)) { readp = &record[records_read]; records_read += fread(readp, sizeof(struct kvp_record), ENTRIES_PER_BLOCK, filep); if (!feof(filep)) { /* * We have more data to read. */ num_blocks++; record = realloc(record, alloc_unit * num_blocks); if (record == NULL) { fclose(filep); return 1; } continue; } break; } kvp_file_info[i].fd = fd; kvp_file_info[i].num_blocks = num_blocks; kvp_file_info[i].records = record; kvp_file_info[i].num_records = records_read; fclose(filep); } return 0; } static int kvp_key_delete(int pool, __u8 *key, int key_size) { int i; int j, k; int num_records; struct kvp_record *record; /* * First update the in-memory state. */ kvp_update_mem_state(pool); num_records = kvp_file_info[pool].num_records; record = kvp_file_info[pool].records; for (i = 0; i < num_records; i++) { if (memcmp(key, record[i].key, key_size)) continue; /* * Found a match; just move the remaining * entries up. */ if (i == num_records) { kvp_file_info[pool].num_records--; kvp_update_file(pool); return 0; } j = i; k = j + 1; for (; k < num_records; k++) { strcpy(record[j].key, record[k].key); strcpy(record[j].value, record[k].value); j++; } kvp_file_info[pool].num_records--; kvp_update_file(pool); return 0; } return 1; } static int kvp_key_add_or_modify(int pool, __u8 *key, int key_size, __u8 *value, int value_size) { int i; int num_records; struct kvp_record *record; int num_blocks; if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) || (value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) return 1; /* * First update the in-memory state. */ kvp_update_mem_state(pool); num_records = kvp_file_info[pool].num_records; record = kvp_file_info[pool].records; num_blocks = kvp_file_info[pool].num_blocks; for (i = 0; i < num_records; i++) { if (memcmp(key, record[i].key, key_size)) continue; /* * Found a match; just update the value - * this is the modify case. */ memcpy(record[i].value, value, value_size); kvp_update_file(pool); return 0; } /* * Need to add a new entry; */ if (num_records == (ENTRIES_PER_BLOCK * num_blocks)) { /* Need to allocate a larger array for reg entries. */ record = realloc(record, sizeof(struct kvp_record) * ENTRIES_PER_BLOCK * (num_blocks + 1)); if (record == NULL) return 1; kvp_file_info[pool].num_blocks++; } memcpy(record[i].value, value, value_size); memcpy(record[i].key, key, key_size); kvp_file_info[pool].records = record; kvp_file_info[pool].num_records++; kvp_update_file(pool); return 0; } static int kvp_get_value(int pool, __u8 *key, int key_size, __u8 *value, int value_size) { int i; int num_records; struct kvp_record *record; if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) || (value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) return 1; /* * First update the in-memory state. */ kvp_update_mem_state(pool); num_records = kvp_file_info[pool].num_records; record = kvp_file_info[pool].records; for (i = 0; i < num_records; i++) { if (memcmp(key, record[i].key, key_size)) continue; /* * Found a match; just copy the value out. */ memcpy(value, record[i].value, value_size); return 0; } return 1; } static int kvp_pool_enumerate(int pool, int index, __u8 *key, int key_size, __u8 *value, int value_size) { struct kvp_record *record; /* * First update our in-memory database. */ kvp_update_mem_state(pool); record = kvp_file_info[pool].records; if (index >= kvp_file_info[pool].num_records) { return 1; } memcpy(key, record[index].key, key_size); memcpy(value, record[index].value, value_size); return 0; } void kvp_get_os_info(void) { FILE *file; char *p, buf[512]; uname(&uts_buf); os_build = uts_buf.release; processor_arch = uts_buf.machine; /* * The current windows host (win7) expects the build * string to be of the form: x.y.z * Strip additional information we may have. */ p = strchr(os_build, '-'); if (p) *p = '\0'; file = fopen("/etc/SuSE-release", "r"); if (file != NULL) goto kvp_osinfo_found; file = fopen("/etc/redhat-release", "r"); if (file != NULL) goto kvp_osinfo_found; /* * Add code for other supported platforms. */ /* * We don't have information about the os. */ os_name = uts_buf.sysname; return; kvp_osinfo_found: /* up to three lines */ p = fgets(buf, sizeof(buf), file); if (p) { p = strchr(buf, '\n'); if (p) *p = '\0'; p = strdup(buf); if (!p) goto done; os_name = p; /* second line */ p = fgets(buf, sizeof(buf), file); if (p) { p = strchr(buf, '\n'); if (p) *p = '\0'; p = strdup(buf); if (!p) goto done; os_major = p; /* third line */ p = fgets(buf, sizeof(buf), file); if (p) { p = strchr(buf, '\n'); if (p) *p = '\0'; p = strdup(buf); if (p) os_minor = p; } } } done: fclose(file); return; } static void kvp_process_ipconfig_file(char *cmd, char *config_buf, int len, int element_size, int offset) { char buf[256]; char *p; char *x; FILE *file; /* * First execute the command. */ file = popen(cmd, "r"); if (file == NULL) return; if (offset == 0) memset(config_buf, 0, len); while ((p = fgets(buf, sizeof(buf), file)) != NULL) { if ((len - strlen(config_buf)) < (element_size + 1)) break; x = strchr(p, '\n'); *x = '\0'; strcat(config_buf, p); strcat(config_buf, ";"); } pclose(file); } static void kvp_get_ipconfig_info(char *if_name, struct hv_kvp_ipaddr_value *buffer) { char cmd[512]; /* * Get the address of default gateway (ipv4). */ sprintf(cmd, "%s %s", "ip route show dev", if_name); strcat(cmd, " | awk '/default/ {print $3 }'"); /* * Execute the command to gather gateway info. */ kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way, (MAX_GATEWAY_SIZE * 2), INET_ADDRSTRLEN, 0); /* * Get the address of default gateway (ipv6). */ sprintf(cmd, "%s %s", "ip -f inet6 route show dev", if_name); strcat(cmd, " | awk '/default/ {print $3 }'"); /* * Execute the command to gather gateway info (ipv6). */ kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way, (MAX_GATEWAY_SIZE * 2), INET6_ADDRSTRLEN, 1); } static unsigned int hweight32(unsigned int *w) { unsigned int res = *w - ((*w >> 1) & 0x55555555); res = (res & 0x33333333) + ((res >> 2) & 0x33333333); res = (res + (res >> 4)) & 0x0F0F0F0F; res = res + (res >> 8); return (res + (res >> 16)) & 0x000000FF; } static int kvp_process_ip_address(void *addrp, int family, char *buffer, int length, int *offset) { struct sockaddr_in *addr; struct sockaddr_in6 *addr6; int addr_length; char tmp[50]; const char *str; if (family == AF_INET) { addr = (struct sockaddr_in *)addrp; str = inet_ntop(family, &addr->sin_addr, tmp, 50); addr_length = INET_ADDRSTRLEN; } else { addr6 = (struct sockaddr_in6 *)addrp; str = inet_ntop(family, &addr6->sin6_addr.s6_addr, tmp, 50); addr_length = INET6_ADDRSTRLEN; } if ((length - *offset) < addr_length + 1) return 1; if (str == NULL) { strcpy(buffer, "inet_ntop failed\n"); return 1; } if (*offset == 0) strcpy(buffer, tmp); else strcat(buffer, tmp); strcat(buffer, ";"); *offset += strlen(str) + 1; return 0; } static int kvp_get_ip_address(int family, char *if_name, int op, void *out_buffer, int length) { struct ifaddrs *ifap; struct ifaddrs *curp; int offset = 0; int sn_offset = 0; int error = 0; char *buffer; struct hv_kvp_ipaddr_value *ip_buffer; char cidr_mask[5]; /* /xyz */ int weight; int i; unsigned int *w; char *sn_str; struct sockaddr_in6 *addr6; if (op == KVP_OP_ENUMERATE) { buffer = out_buffer; } else { ip_buffer = out_buffer; buffer = (char *)ip_buffer->ip_addr; ip_buffer->addr_family = 0; } /* * On entry into this function, the buffer is capable of holding the * maximum key value. */ if (getifaddrs(&ifap)) { strcpy(buffer, "getifaddrs failed\n"); return 1; } curp = ifap; while (curp != NULL) { if (curp->ifa_addr == NULL) { curp = curp->ifa_next; continue; } if ((if_name != NULL) && (strncmp(curp->ifa_name, if_name, strlen(if_name)))) { /* * We want info about a specific interface; * just continue. */ curp = curp->ifa_next; continue; } /* * We only support two address families: AF_INET and AF_INET6. * If a family value of 0 is specified, we collect both * supported address families; if not we gather info on * the specified address family. */ if ((family != 0) && (curp->ifa_addr->sa_family != family)) { curp = curp->ifa_next; continue; } if ((curp->ifa_addr->sa_family != AF_INET) && (curp->ifa_addr->sa_family != AF_INET6)) { curp = curp->ifa_next; continue; } if (op == KVP_OP_GET_IP_INFO) { /* * Gather info other than the IP address. * IP address info will be gathered later. */ if (curp->ifa_addr->sa_family == AF_INET) { ip_buffer->addr_family |= ADDR_FAMILY_IPV4; /* * Get subnet info. */ error = kvp_process_ip_address( curp->ifa_netmask, AF_INET, (char *) ip_buffer->sub_net, length, &sn_offset); if (error) goto gather_ipaddr; } else { ip_buffer->addr_family |= ADDR_FAMILY_IPV6; /* * Get subnet info in CIDR format. */ weight = 0; sn_str = (char *)ip_buffer->sub_net; addr6 = (struct sockaddr_in6 *) curp->ifa_netmask; w = addr6->sin6_addr.s6_addr32; for (i = 0; i < 4; i++) weight += hweight32(&w[i]); sprintf(cidr_mask, "/%d", weight); if ((length - sn_offset) < (strlen(cidr_mask) + 1)) goto gather_ipaddr; if (sn_offset == 0) strcpy(sn_str, cidr_mask); else strcat(sn_str, cidr_mask); strcat((char *)ip_buffer->sub_net, ";"); sn_offset += strlen(sn_str) + 1; } /* * Collect other ip related configuration info. */ kvp_get_ipconfig_info(if_name, ip_buffer); } gather_ipaddr: error = kvp_process_ip_address(curp->ifa_addr, curp->ifa_addr->sa_family, buffer, length, &offset); if (error) goto getaddr_done; curp = curp->ifa_next; } getaddr_done: freeifaddrs(ifap); return error; } static int kvp_get_domain_name(char *buffer, int length) { struct addrinfo hints, *info ; int error = 0; gethostname(buffer, length); memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_INET; /*Get only ipv4 addrinfo. */ hints.ai_socktype = SOCK_STREAM; hints.ai_flags = AI_CANONNAME; error = getaddrinfo(buffer, NULL, &hints, &info); if (error != 0) { strcpy(buffer, "getaddrinfo failed\n"); return error; } strcpy(buffer, info->ai_canonname); freeaddrinfo(info); return error; } static int netlink_send(int fd, struct cn_msg *msg) { struct nlmsghdr *nlh; unsigned int size; struct msghdr message; char buffer[64]; struct iovec iov[2]; size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len); nlh = (struct nlmsghdr *)buffer; nlh->nlmsg_seq = 0; nlh->nlmsg_pid = getpid(); nlh->nlmsg_type = NLMSG_DONE; nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh)); nlh->nlmsg_flags = 0; iov[0].iov_base = nlh; iov[0].iov_len = sizeof(*nlh); iov[1].iov_base = msg; iov[1].iov_len = size; memset(&message, 0, sizeof(message)); message.msg_name = &addr; message.msg_namelen = sizeof(addr); message.msg_iov = iov; message.msg_iovlen = 2; return sendmsg(fd, &message, 0); } int main(void) { int fd, len, sock_opt; int error; struct cn_msg *message; struct pollfd pfd; struct nlmsghdr *incoming_msg; struct cn_msg *incoming_cn_msg; struct hv_kvp_msg *hv_msg; char *p; char *key_value; char *key_name; int op; int pool; daemon(1, 0); openlog("KVP", 0, LOG_USER); syslog(LOG_INFO, "KVP starting; pid is:%d", getpid()); /* * Retrieve OS release information. */ kvp_get_os_info(); if (kvp_file_init()) { syslog(LOG_ERR, "Failed to initialize the pools"); exit(-1); } fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR); if (fd < 0) { syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd); exit(-1); } addr.nl_family = AF_NETLINK; addr.nl_pad = 0; addr.nl_pid = 0; addr.nl_groups = CN_KVP_IDX; error = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); if (error < 0) { syslog(LOG_ERR, "bind failed; error:%d", error); close(fd); exit(-1); } sock_opt = addr.nl_groups; setsockopt(fd, 270, 1, &sock_opt, sizeof(sock_opt)); /* * Register ourselves with the kernel. */ message = (struct cn_msg *)kvp_send_buffer; message->id.idx = CN_KVP_IDX; message->id.val = CN_KVP_VAL; hv_msg = (struct hv_kvp_msg *)message->data; hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1; message->ack = 0; message->len = sizeof(struct hv_kvp_msg); len = netlink_send(fd, message); if (len < 0) { syslog(LOG_ERR, "netlink_send failed; error:%d", len); close(fd); exit(-1); } pfd.fd = fd; while (1) { struct sockaddr *addr_p = (struct sockaddr *) &addr; socklen_t addr_l = sizeof(addr); pfd.events = POLLIN; pfd.revents = 0; poll(&pfd, 1, -1); len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0, addr_p, &addr_l); if (len < 0 || addr.nl_pid) { syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s", addr.nl_pid, errno, strerror(errno)); close(fd); return -1; } incoming_msg = (struct nlmsghdr *)kvp_recv_buffer; incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg); hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data; /* * We will use the KVP header information to pass back * the error from this daemon. So, first copy the state * and set the error code to success. */ op = hv_msg->kvp_hdr.operation; pool = hv_msg->kvp_hdr.pool; hv_msg->error = HV_S_OK; if ((in_hand_shake) && (op == KVP_OP_REGISTER1)) { /* * Driver is registering with us; stash away the version * information. */ in_hand_shake = 0; p = (char *)hv_msg->body.kvp_register.version; lic_version = malloc(strlen(p) + 1); if (lic_version) { strcpy(lic_version, p); syslog(LOG_INFO, "KVP LIC Version: %s", lic_version); } else { syslog(LOG_ERR, "malloc failed"); } continue; } switch (op) { case KVP_OP_SET: if (kvp_key_add_or_modify(pool, hv_msg->body.kvp_set.data.key, hv_msg->body.kvp_set.data.key_size, hv_msg->body.kvp_set.data.value, hv_msg->body.kvp_set.data.value_size)) hv_msg->error = HV_S_CONT; break; case KVP_OP_GET: if (kvp_get_value(pool, hv_msg->body.kvp_set.data.key, hv_msg->body.kvp_set.data.key_size, hv_msg->body.kvp_set.data.value, hv_msg->body.kvp_set.data.value_size)) hv_msg->error = HV_S_CONT; break; case KVP_OP_DELETE: if (kvp_key_delete(pool, hv_msg->body.kvp_delete.key, hv_msg->body.kvp_delete.key_size)) hv_msg->error = HV_S_CONT; break; default: break; } if (op != KVP_OP_ENUMERATE) goto kvp_done; /* * If the pool is KVP_POOL_AUTO, dynamically generate * both the key and the value; if not read from the * appropriate pool. */ if (pool != KVP_POOL_AUTO) { if (kvp_pool_enumerate(pool, hv_msg->body.kvp_enum_data.index, hv_msg->body.kvp_enum_data.data.key, HV_KVP_EXCHANGE_MAX_KEY_SIZE, hv_msg->body.kvp_enum_data.data.value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) hv_msg->error = HV_S_CONT; goto kvp_done; } hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data; key_name = (char *)hv_msg->body.kvp_enum_data.data.key; key_value = (char *)hv_msg->body.kvp_enum_data.data.value; switch (hv_msg->body.kvp_enum_data.index) { case FullyQualifiedDomainName: kvp_get_domain_name(key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE); strcpy(key_name, "FullyQualifiedDomainName"); break; case IntegrationServicesVersion: strcpy(key_name, "IntegrationServicesVersion"); strcpy(key_value, lic_version); break; case NetworkAddressIPv4: kvp_get_ip_address(AF_INET, NULL, KVP_OP_ENUMERATE, key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE); strcpy(key_name, "NetworkAddressIPv4"); break; case NetworkAddressIPv6: kvp_get_ip_address(AF_INET6, NULL, KVP_OP_ENUMERATE, key_value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE); strcpy(key_name, "NetworkAddressIPv6"); break; case OSBuildNumber: strcpy(key_value, os_build); strcpy(key_name, "OSBuildNumber"); break; case OSName: strcpy(key_value, os_name); strcpy(key_name, "OSName"); break; case OSMajorVersion: strcpy(key_value, os_major); strcpy(key_name, "OSMajorVersion"); break; case OSMinorVersion: strcpy(key_value, os_minor); strcpy(key_name, "OSMinorVersion"); break; case OSVersion: strcpy(key_value, os_build); strcpy(key_name, "OSVersion"); break; case ProcessorArchitecture: strcpy(key_value, processor_arch); strcpy(key_name, "ProcessorArchitecture"); break; default: hv_msg->error = HV_S_CONT; break; } /* * Send the value back to the kernel. The response is * already in the receive buffer. Update the cn_msg header to * reflect the key value that has been added to the message */ kvp_done: incoming_cn_msg->id.idx = CN_KVP_IDX; incoming_cn_msg->id.val = CN_KVP_VAL; incoming_cn_msg->ack = 0; incoming_cn_msg->len = sizeof(struct hv_kvp_msg); len = netlink_send(fd, incoming_cn_msg); if (len < 0) { syslog(LOG_ERR, "net_link send failed; error:%d", len); exit(-1); } } }