/* * An implementation of key value pair (KVP) functionality for Linux. * * * Copyright (C) 2010, Novell, Inc. * Author : K. Y. Srinivasan <ksrinivasan@novell.com> * * 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. * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/net.h> #include <linux/nls.h> #include <linux/connector.h> #include <linux/workqueue.h> #include <linux/hyperv.h> /* * Global state maintained for transaction that is being processed. * Note that only one transaction can be active at any point in time. * * This state is set when we receive a request from the host; we * cleanup this state when the transaction is completed - when we respond * to the host with the key value. */ static struct { bool active; /* transaction status - active or not */ int recv_len; /* number of bytes received. */ struct hv_kvp_msg *kvp_msg; /* current message */ struct vmbus_channel *recv_channel; /* chn we got the request */ u64 recv_req_id; /* request ID. */ void *kvp_context; /* for the channel callback */ } kvp_transaction; /* * Before we can accept KVP messages from the host, we need * to handshake with the user level daemon. This state tracks * if we are in the handshake phase. */ static bool in_hand_shake = true; /* * This state maintains the version number registered by the daemon. */ static int dm_reg_value; static void kvp_send_key(struct work_struct *dummy); static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error); static void kvp_work_func(struct work_struct *dummy); static void kvp_register(int); static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func); static DECLARE_WORK(kvp_sendkey_work, kvp_send_key); static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL }; static const char kvp_name[] = "kvp_kernel_module"; static u8 *recv_buffer; /* * Register the kernel component with the user-level daemon. * As part of this registration, pass the LIC version number. */ static void kvp_register(int reg_value) { struct cn_msg *msg; struct hv_kvp_msg *kvp_msg; char *version; msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC); if (msg) { kvp_msg = (struct hv_kvp_msg *)msg->data; version = kvp_msg->body.kvp_register.version; msg->id.idx = CN_KVP_IDX; msg->id.val = CN_KVP_VAL; kvp_msg->kvp_hdr.operation = reg_value; strcpy(version, HV_DRV_VERSION); msg->len = sizeof(struct hv_kvp_msg); cn_netlink_send(msg, 0, GFP_ATOMIC); kfree(msg); } } static void kvp_work_func(struct work_struct *dummy) { /* * If the timer fires, the user-mode component has not responded; * process the pending transaction. */ kvp_respond_to_host(NULL, HV_E_FAIL); } static int kvp_handle_handshake(struct hv_kvp_msg *msg) { int ret = 1; switch (msg->kvp_hdr.operation) { case KVP_OP_REGISTER: dm_reg_value = KVP_OP_REGISTER; pr_info("KVP: IP injection functionality not available\n"); pr_info("KVP: Upgrade the KVP daemon\n"); break; case KVP_OP_REGISTER1: dm_reg_value = KVP_OP_REGISTER1; break; default: pr_info("KVP: incompatible daemon\n"); pr_info("KVP: KVP version: %d, Daemon version: %d\n", KVP_OP_REGISTER1, msg->kvp_hdr.operation); ret = 0; } if (ret) { /* * We have a compatible daemon; complete the handshake. */ pr_info("KVP: user-mode registering done.\n"); kvp_register(dm_reg_value); kvp_transaction.active = false; if (kvp_transaction.kvp_context) hv_kvp_onchannelcallback(kvp_transaction.kvp_context); } return ret; } /* * Callback when data is received from user mode. */ static void kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) { struct hv_kvp_msg *message; struct hv_kvp_msg_enumerate *data; int error = 0; message = (struct hv_kvp_msg *)msg->data; /* * If we are negotiating the version information * with the daemon; handle that first. */ if (in_hand_shake) { if (kvp_handle_handshake(message)) in_hand_shake = false; return; } /* * Based on the version of the daemon, we propagate errors from the * daemon differently. */ data = &message->body.kvp_enum_data; switch (dm_reg_value) { case KVP_OP_REGISTER: /* * Null string is used to pass back error condition. */ if (data->data.key[0] == 0) error = HV_S_CONT; break; case KVP_OP_REGISTER1: /* * We use the message header information from * the user level daemon to transmit errors. */ error = message->error; break; } /* * Complete the transaction by forwarding the key value * to the host. But first, cancel the timeout. */ if (cancel_delayed_work_sync(&kvp_work)) kvp_respond_to_host(message, error); } static int process_ob_ipinfo(void *in_msg, void *out_msg, int op) { struct hv_kvp_msg *in = in_msg; struct hv_kvp_ip_msg *out = out_msg; int len; switch (op) { case KVP_OP_GET_IP_INFO: /* * Transform all parameters into utf16 encoding. */ len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr, strlen((char *)in->body.kvp_ip_val.ip_addr), UTF16_HOST_ENDIAN, (wchar_t *)out->kvp_ip_val.ip_addr, MAX_IP_ADDR_SIZE); if (len < 0) return len; len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net, strlen((char *)in->body.kvp_ip_val.sub_net), UTF16_HOST_ENDIAN, (wchar_t *)out->kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE); if (len < 0) return len; len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way, strlen((char *)in->body.kvp_ip_val.gate_way), UTF16_HOST_ENDIAN, (wchar_t *)out->kvp_ip_val.gate_way, MAX_GATEWAY_SIZE); if (len < 0) return len; len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr, strlen((char *)in->body.kvp_ip_val.dns_addr), UTF16_HOST_ENDIAN, (wchar_t *)out->kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE); if (len < 0) return len; len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id, strlen((char *)in->body.kvp_ip_val.adapter_id), UTF16_HOST_ENDIAN, (wchar_t *)out->kvp_ip_val.adapter_id, MAX_IP_ADDR_SIZE); if (len < 0) return len; out->kvp_ip_val.dhcp_enabled = in->body.kvp_ip_val.dhcp_enabled; out->kvp_ip_val.addr_family = in->body.kvp_ip_val.addr_family; } return 0; } static void process_ib_ipinfo(void *in_msg, void *out_msg, int op) { struct hv_kvp_ip_msg *in = in_msg; struct hv_kvp_msg *out = out_msg; switch (op) { case KVP_OP_SET_IP_INFO: /* * Transform all parameters into utf8 encoding. */ utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr, MAX_IP_ADDR_SIZE, UTF16_LITTLE_ENDIAN, (__u8 *)out->body.kvp_ip_val.ip_addr, MAX_IP_ADDR_SIZE); utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE, UTF16_LITTLE_ENDIAN, (__u8 *)out->body.kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE); utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way, MAX_GATEWAY_SIZE, UTF16_LITTLE_ENDIAN, (__u8 *)out->body.kvp_ip_val.gate_way, MAX_GATEWAY_SIZE); utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE, UTF16_LITTLE_ENDIAN, (__u8 *)out->body.kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE); out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled; default: utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id, MAX_ADAPTER_ID_SIZE, UTF16_LITTLE_ENDIAN, (__u8 *)out->body.kvp_ip_val.adapter_id, MAX_ADAPTER_ID_SIZE); out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family; } } static void kvp_send_key(struct work_struct *dummy) { struct cn_msg *msg; struct hv_kvp_msg *message; struct hv_kvp_msg *in_msg; __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation; __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool; __u32 val32; __u64 val64; msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC); if (!msg) return; msg->id.idx = CN_KVP_IDX; msg->id.val = CN_KVP_VAL; message = (struct hv_kvp_msg *)msg->data; message->kvp_hdr.operation = operation; message->kvp_hdr.pool = pool; in_msg = kvp_transaction.kvp_msg; /* * The key/value strings sent from the host are encoded in * 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 HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee * that the strings can be properly terminated! */ switch (message->kvp_hdr.operation) { case KVP_OP_SET_IP_INFO: process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO); break; case KVP_OP_GET_IP_INFO: process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO); break; case KVP_OP_SET: switch (in_msg->body.kvp_set.data.value_type) { case REG_SZ: /* * The value is a string - utf16 encoding. */ message->body.kvp_set.data.value_size = utf16s_to_utf8s( (wchar_t *)in_msg->body.kvp_set.data.value, in_msg->body.kvp_set.data.value_size, UTF16_LITTLE_ENDIAN, message->body.kvp_set.data.value, HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1; break; case REG_U32: /* * The value is a 32 bit scalar. * We save this as a utf8 string. */ val32 = in_msg->body.kvp_set.data.value_u32; message->body.kvp_set.data.value_size = sprintf(message->body.kvp_set.data.value, "%d", val32) + 1; break; case REG_U64: /* * The value is a 64 bit scalar. * We save this as a utf8 string. */ val64 = in_msg->body.kvp_set.data.value_u64; message->body.kvp_set.data.value_size = sprintf(message->body.kvp_set.data.value, "%llu", val64) + 1; break; } case KVP_OP_GET: message->body.kvp_set.data.key_size = utf16s_to_utf8s( (wchar_t *)in_msg->body.kvp_set.data.key, in_msg->body.kvp_set.data.key_size, UTF16_LITTLE_ENDIAN, message->body.kvp_set.data.key, HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1; break; case KVP_OP_DELETE: message->body.kvp_delete.key_size = utf16s_to_utf8s( (wchar_t *)in_msg->body.kvp_delete.key, in_msg->body.kvp_delete.key_size, UTF16_LITTLE_ENDIAN, message->body.kvp_delete.key, HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1; break; case KVP_OP_ENUMERATE: message->body.kvp_enum_data.index = in_msg->body.kvp_enum_data.index; break; } msg->len = sizeof(struct hv_kvp_msg); cn_netlink_send(msg, 0, GFP_ATOMIC); kfree(msg); return; } /* * Send a response back to the host. */ static void kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error) { struct hv_kvp_msg *kvp_msg; struct hv_kvp_exchg_msg_value *kvp_data; char *key_name; char *value; struct icmsg_hdr *icmsghdrp; int keylen = 0; int valuelen = 0; u32 buf_len; struct vmbus_channel *channel; u64 req_id; int ret; /* * If a transaction is not active; log and return. */ if (!kvp_transaction.active) { /* * This is a spurious call! */ pr_warn("KVP: Transaction not active\n"); return; } /* * Copy the global state for completing the transaction. Note that * only one transaction can be active at a time. */ buf_len = kvp_transaction.recv_len; channel = kvp_transaction.recv_channel; req_id = kvp_transaction.recv_req_id; kvp_transaction.active = false; icmsghdrp = (struct icmsg_hdr *) &recv_buffer[sizeof(struct vmbuspipe_hdr)]; if (channel->onchannel_callback == NULL) /* * We have raced with util driver being unloaded; * silently return. */ return; icmsghdrp->status = error; /* * If the error parameter is set, terminate the host's enumeration * on this pool. */ if (error) { /* * Something failed or we have timedout; * terminate the current host-side iteration. */ goto response_done; } kvp_msg = (struct hv_kvp_msg *) &recv_buffer[sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr)]; switch (kvp_transaction.kvp_msg->kvp_hdr.operation) { case KVP_OP_GET_IP_INFO: ret = process_ob_ipinfo(msg_to_host, (struct hv_kvp_ip_msg *)kvp_msg, KVP_OP_GET_IP_INFO); if (ret < 0) icmsghdrp->status = HV_E_FAIL; goto response_done; case KVP_OP_SET_IP_INFO: goto response_done; case KVP_OP_GET: kvp_data = &kvp_msg->body.kvp_get.data; goto copy_value; case KVP_OP_SET: case KVP_OP_DELETE: goto response_done; default: break; } kvp_data = &kvp_msg->body.kvp_enum_data.data; key_name = msg_to_host->body.kvp_enum_data.data.key; /* * The windows host expects the key/value pair to be encoded * in utf16. Ensure that the key/value size reported to the host * will be less than or equal to the MAX size (including the * terminating character). */ keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN, (wchar_t *) kvp_data->key, (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2); kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */ copy_value: value = msg_to_host->body.kvp_enum_data.data.value; valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN, (wchar_t *) kvp_data->value, (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2); kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */ /* * If the utf8s to utf16s conversion failed; notify host * of the error. */ if ((keylen < 0) || (valuelen < 0)) icmsghdrp->status = HV_E_FAIL; kvp_data->value_type = REG_SZ; /* all our values are strings */ response_done: icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; vmbus_sendpacket(channel, recv_buffer, buf_len, req_id, VM_PKT_DATA_INBAND, 0); } /* * This callback is invoked when we get a KVP message from the host. * The host ensures that only one KVP transaction can be active at a time. * KVP implementation in Linux needs to forward the key to a user-mde * component to retrive the corresponding value. Consequently, we cannot * respond to the host in the conext of this callback. Since the host * guarantees that at most only one transaction can be active at a time, * we stash away the transaction state in a set of global variables. */ void hv_kvp_onchannelcallback(void *context) { struct vmbus_channel *channel = context; u32 recvlen; u64 requestid; struct hv_kvp_msg *kvp_msg; struct icmsg_hdr *icmsghdrp; struct icmsg_negotiate *negop = NULL; if (kvp_transaction.active) { /* * We will defer processing this callback once * the current transaction is complete. */ kvp_transaction.kvp_context = context; return; } vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen, &requestid); if (recvlen > 0) { icmsghdrp = (struct icmsg_hdr *)&recv_buffer[ sizeof(struct vmbuspipe_hdr)]; if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) { vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer, MAX_SRV_VER, MAX_SRV_VER); } else { kvp_msg = (struct hv_kvp_msg *)&recv_buffer[ sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr)]; /* * Stash away this global state for completing the * transaction; note transactions are serialized. */ kvp_transaction.recv_len = recvlen; kvp_transaction.recv_channel = channel; kvp_transaction.recv_req_id = requestid; kvp_transaction.active = true; kvp_transaction.kvp_msg = kvp_msg; /* * Get the information from the * user-mode component. * component. This transaction will be * completed when we get the value from * the user-mode component. * Set a timeout to deal with * user-mode not responding. */ schedule_work(&kvp_sendkey_work); schedule_delayed_work(&kvp_work, 5*HZ); return; } icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; vmbus_sendpacket(channel, recv_buffer, recvlen, requestid, VM_PKT_DATA_INBAND, 0); } } int hv_kvp_init(struct hv_util_service *srv) { int err; err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback); if (err) return err; recv_buffer = srv->recv_buffer; /* * When this driver loads, the user level daemon that * processes the host requests may not yet be running. * Defer processing channel callbacks until the daemon * has registered. */ kvp_transaction.active = true; return 0; } void hv_kvp_deinit(void) { cn_del_callback(&kvp_id); cancel_delayed_work_sync(&kvp_work); cancel_work_sync(&kvp_sendkey_work); }