diff options
Diffstat (limited to 'fs/cifs/cifs_swn.c')
| -rw-r--r-- | fs/cifs/cifs_swn.c | 674 |
1 files changed, 674 insertions, 0 deletions
diff --git a/fs/cifs/cifs_swn.c b/fs/cifs/cifs_swn.c new file mode 100644 index 000000000000..7233c6a7e6d7 --- /dev/null +++ b/fs/cifs/cifs_swn.c @@ -0,0 +1,674 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Witness Service client for CIFS + * + * Copyright (c) 2020 Samuel Cabrero <scabrero@suse.de> + */ + +#include <linux/kref.h> +#include <net/genetlink.h> +#include <uapi/linux/cifs/cifs_netlink.h> + +#include "cifs_swn.h" +#include "cifsglob.h" +#include "cifsproto.h" +#include "fscache.h" +#include "cifs_debug.h" +#include "netlink.h" + +static DEFINE_IDR(cifs_swnreg_idr); +static DEFINE_MUTEX(cifs_swnreg_idr_mutex); + +struct cifs_swn_reg { + int id; + struct kref ref_count; + + const char *net_name; + const char *share_name; + bool net_name_notify; + bool share_name_notify; + bool ip_notify; + + struct cifs_tcon *tcon; +}; + +static int cifs_swn_auth_info_krb(struct cifs_tcon *tcon, struct sk_buff *skb) +{ + int ret; + + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_KRB_AUTH); + if (ret < 0) + return ret; + + return 0; +} + +static int cifs_swn_auth_info_ntlm(struct cifs_tcon *tcon, struct sk_buff *skb) +{ + int ret; + + if (tcon->ses->user_name != NULL) { + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_USER_NAME, tcon->ses->user_name); + if (ret < 0) + return ret; + } + + if (tcon->ses->password != NULL) { + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_PASSWORD, tcon->ses->password); + if (ret < 0) + return ret; + } + + if (tcon->ses->domainName != NULL) { + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_DOMAIN_NAME, tcon->ses->domainName); + if (ret < 0) + return ret; + } + + return 0; +} + +/* + * Sends a register message to the userspace daemon based on the registration. + * The authentication information to connect to the witness service is bundled + * into the message. + */ +static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg) +{ + struct sk_buff *skb; + struct genlmsghdr *hdr; + enum securityEnum authtype; + struct sockaddr_storage *addr; + int ret; + + skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (skb == NULL) { + ret = -ENOMEM; + goto fail; + } + + hdr = genlmsg_put(skb, 0, 0, &cifs_genl_family, 0, CIFS_GENL_CMD_SWN_REGISTER); + if (hdr == NULL) { + ret = -ENOMEM; + goto nlmsg_fail; + } + + ret = nla_put_u32(skb, CIFS_GENL_ATTR_SWN_REGISTRATION_ID, swnreg->id); + if (ret < 0) + goto nlmsg_fail; + + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_NET_NAME, swnreg->net_name); + if (ret < 0) + goto nlmsg_fail; + + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME, swnreg->share_name); + if (ret < 0) + goto nlmsg_fail; + + /* + * If there is an address stored use it instead of the server address, because we are + * in the process of reconnecting to it after a share has been moved or we have been + * told to switch to it (client move message). In these cases we unregister from the + * server address and register to the new address when we receive the notification. + */ + if (swnreg->tcon->ses->server->use_swn_dstaddr) + addr = &swnreg->tcon->ses->server->swn_dstaddr; + else + addr = &swnreg->tcon->ses->server->dstaddr; + + ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage), addr); + if (ret < 0) + goto nlmsg_fail; + + if (swnreg->net_name_notify) { + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_NET_NAME_NOTIFY); + if (ret < 0) + goto nlmsg_fail; + } + + if (swnreg->share_name_notify) { + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME_NOTIFY); + if (ret < 0) + goto nlmsg_fail; + } + + if (swnreg->ip_notify) { + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_IP_NOTIFY); + if (ret < 0) + goto nlmsg_fail; + } + + authtype = cifs_select_sectype(swnreg->tcon->ses->server, swnreg->tcon->ses->sectype); + switch (authtype) { + case Kerberos: + ret = cifs_swn_auth_info_krb(swnreg->tcon, skb); + if (ret < 0) { + cifs_dbg(VFS, "%s: Failed to get kerberos auth info: %d\n", __func__, ret); + goto nlmsg_fail; + } + break; + case NTLMv2: + case RawNTLMSSP: + ret = cifs_swn_auth_info_ntlm(swnreg->tcon, skb); + if (ret < 0) { + cifs_dbg(VFS, "%s: Failed to get NTLM auth info: %d\n", __func__, ret); + goto nlmsg_fail; + } + break; + default: + cifs_dbg(VFS, "%s: secType %d not supported!\n", __func__, authtype); + ret = -EINVAL; + goto nlmsg_fail; + } + + genlmsg_end(skb, hdr); + genlmsg_multicast(&cifs_genl_family, skb, 0, CIFS_GENL_MCGRP_SWN, GFP_ATOMIC); + + cifs_dbg(FYI, "%s: Message to register for network name %s with id %d sent\n", __func__, + swnreg->net_name, swnreg->id); + + return 0; + +nlmsg_fail: + genlmsg_cancel(skb, hdr); + nlmsg_free(skb); +fail: + return ret; +} + +/* + * Sends an uregister message to the userspace daemon based on the registration + */ +static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg) +{ + struct sk_buff *skb; + struct genlmsghdr *hdr; + int ret; + + skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (skb == NULL) + return -ENOMEM; + + hdr = genlmsg_put(skb, 0, 0, &cifs_genl_family, 0, CIFS_GENL_CMD_SWN_UNREGISTER); + if (hdr == NULL) { + ret = -ENOMEM; + goto nlmsg_fail; + } + + ret = nla_put_u32(skb, CIFS_GENL_ATTR_SWN_REGISTRATION_ID, swnreg->id); + if (ret < 0) + goto nlmsg_fail; + + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_NET_NAME, swnreg->net_name); + if (ret < 0) + goto nlmsg_fail; + + ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME, swnreg->share_name); + if (ret < 0) + goto nlmsg_fail; + + ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage), + &swnreg->tcon->ses->server->dstaddr); + if (ret < 0) + goto nlmsg_fail; + + if (swnreg->net_name_notify) { + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_NET_NAME_NOTIFY); + if (ret < 0) + goto nlmsg_fail; + } + + if (swnreg->share_name_notify) { + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME_NOTIFY); + if (ret < 0) + goto nlmsg_fail; + } + + if (swnreg->ip_notify) { + ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_IP_NOTIFY); + if (ret < 0) + goto nlmsg_fail; + } + + genlmsg_end(skb, hdr); + genlmsg_multicast(&cifs_genl_family, skb, 0, CIFS_GENL_MCGRP_SWN, GFP_ATOMIC); + + cifs_dbg(FYI, "%s: Message to unregister for network name %s with id %d sent\n", __func__, + swnreg->net_name, swnreg->id); + + return 0; + +nlmsg_fail: + genlmsg_cancel(skb, hdr); + nlmsg_free(skb); + return ret; +} + +/* + * Try to find a matching registration for the tcon's server name and share name. + * Calls to this function must be protected by cifs_swnreg_idr_mutex. + * TODO Try to avoid memory allocations + */ +static struct cifs_swn_reg *cifs_find_swn_reg(struct cifs_tcon *tcon) +{ + struct cifs_swn_reg *swnreg; + int id; + const char *share_name; + const char *net_name; + + net_name = extract_hostname(tcon->tree_name); + if (IS_ERR(net_name)) { + int ret; + + ret = PTR_ERR(net_name); + cifs_dbg(VFS, "%s: failed to extract host name from target '%s': %d\n", + __func__, tcon->tree_name, ret); + return ERR_PTR(-EINVAL); + } + + share_name = extract_sharename(tcon->tree_name); + if (IS_ERR(share_name)) { + int ret; + + ret = PTR_ERR(share_name); + cifs_dbg(VFS, "%s: failed to extract share name from target '%s': %d\n", + __func__, tcon->tree_name, ret); + kfree(net_name); + return ERR_PTR(-EINVAL); + } + + idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) { + if (strcasecmp(swnreg->net_name, net_name) != 0 + || strcasecmp(swnreg->share_name, share_name) != 0) { + continue; + } + + cifs_dbg(FYI, "Existing swn registration for %s:%s found\n", swnreg->net_name, + swnreg->share_name); + + kfree(net_name); + kfree(share_name); + + return swnreg; + } + + kfree(net_name); + kfree(share_name); + + return ERR_PTR(-EEXIST); +} + +/* + * Get a registration for the tcon's server and share name, allocating a new one if it does not + * exists + */ +static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon) +{ + struct cifs_swn_reg *reg = NULL; + int ret; + + mutex_lock(&cifs_swnreg_idr_mutex); + + /* Check if we are already registered for this network and share names */ + reg = cifs_find_swn_reg(tcon); + if (!IS_ERR(reg)) { + kref_get(®->ref_count); + mutex_unlock(&cifs_swnreg_idr_mutex); + return reg; + } else if (PTR_ERR(reg) != -EEXIST) { + mutex_unlock(&cifs_swnreg_idr_mutex); + return reg; + } + + reg = kmalloc(sizeof(struct cifs_swn_reg), GFP_ATOMIC); + if (reg == NULL) { + mutex_unlock(&cifs_swnreg_idr_mutex); + return ERR_PTR(-ENOMEM); + } + + kref_init(®->ref_count); + + reg->id = idr_alloc(&cifs_swnreg_idr, reg, 1, 0, GFP_ATOMIC); + if (reg->id < 0) { + cifs_dbg(FYI, "%s: failed to allocate registration id\n", __func__); + ret = reg->id; + goto fail; + } + + reg->net_name = extract_hostname(tcon->tree_name); + if (IS_ERR(reg->net_name)) { + ret = PTR_ERR(reg->net_name); + cifs_dbg(VFS, "%s: failed to extract host name from target: %d\n", __func__, ret); + goto fail_idr; + } + + reg->share_name = extract_sharename(tcon->tree_name); + if (IS_ERR(reg->share_name)) { + ret = PTR_ERR(reg->share_name); + cifs_dbg(VFS, "%s: failed to extract share name from target: %d\n", __func__, ret); + goto fail_net_name; + } + + reg->net_name_notify = true; + reg->share_name_notify = true; + reg->ip_notify = (tcon->capabilities & SMB2_SHARE_CAP_SCALEOUT); + + reg->tcon = tcon; + + mutex_unlock(&cifs_swnreg_idr_mutex); + + return reg; + +fail_net_name: + kfree(reg->net_name); +fail_idr: + idr_remove(&cifs_swnreg_idr, reg->id); +fail: + kfree(reg); + mutex_unlock(&cifs_swnreg_idr_mutex); + return ERR_PTR(ret); +} + +static void cifs_swn_reg_release(struct kref *ref) +{ + struct cifs_swn_reg *swnreg = container_of(ref, struct cifs_swn_reg, ref_count); + int ret; + + ret = cifs_swn_send_unregister_message(swnreg); + if (ret < 0) + cifs_dbg(VFS, "%s: Failed to send unregister message: %d\n", __func__, ret); + + idr_remove(&cifs_swnreg_idr, swnreg->id); + kfree(swnreg->net_name); + kfree(swnreg->share_name); + kfree(swnreg); +} + +static void cifs_put_swn_reg(struct cifs_swn_reg *swnreg) +{ + mutex_lock(&cifs_swnreg_idr_mutex); + kref_put(&swnreg->ref_count, cifs_swn_reg_release); + mutex_unlock(&cifs_swnreg_idr_mutex); +} + +static int cifs_swn_resource_state_changed(struct cifs_swn_reg *swnreg, const char *name, int state) +{ + switch (state) { + case CIFS_SWN_RESOURCE_STATE_UNAVAILABLE: + cifs_dbg(FYI, "%s: resource name '%s' become unavailable\n", __func__, name); + cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true); + break; + case CIFS_SWN_RESOURCE_STATE_AVAILABLE: + cifs_dbg(FYI, "%s: resource name '%s' become available\n", __func__, name); + cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true); + break; + case CIFS_SWN_RESOURCE_STATE_UNKNOWN: + cifs_dbg(FYI, "%s: resource name '%s' changed to unknown state\n", __func__, name); + break; + } + return 0; +} + +static bool cifs_sockaddr_equal(struct sockaddr_storage *addr1, struct sockaddr_storage *addr2) +{ + if (addr1->ss_family != addr2->ss_family) + return false; + + if (addr1->ss_family == AF_INET) { + return (memcmp(&((const struct sockaddr_in *)addr1)->sin_addr, + &((const struct sockaddr_in *)addr2)->sin_addr, + sizeof(struct in_addr)) == 0); + } + + if (addr1->ss_family == AF_INET6) { + return (memcmp(&((const struct sockaddr_in6 *)addr1)->sin6_addr, + &((const struct sockaddr_in6 *)addr2)->sin6_addr, + sizeof(struct in6_addr)) == 0); + } + + return false; +} + +static int cifs_swn_store_swn_addr(const struct sockaddr_storage *new, + const struct sockaddr_storage *old, + struct sockaddr_storage *dst) +{ + __be16 port = cpu_to_be16(CIFS_PORT); + + if (old->ss_family == AF_INET) { + struct sockaddr_in *ipv4 = (struct sockaddr_in *)old; + + port = ipv4->sin_port; + } else if (old->ss_family == AF_INET6) { + struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)old; + + port = ipv6->sin6_port; + } + + if (new->ss_family == AF_INET) { + struct sockaddr_in *ipv4 = (struct sockaddr_in *)new; + + ipv4->sin_port = port; + } else if (new->ss_family == AF_INET6) { + struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)new; + + ipv6->sin6_port = port; + } + + *dst = *new; + + return 0; +} + +static int cifs_swn_reconnect(struct cifs_tcon *tcon, struct sockaddr_storage *addr) +{ + int ret = 0; + + /* Store the reconnect address */ + cifs_server_lock(tcon->ses->server); + if (cifs_sockaddr_equal(&tcon->ses->server->dstaddr, addr)) + goto unlock; + + ret = cifs_swn_store_swn_addr(addr, &tcon->ses->server->dstaddr, + &tcon->ses->server->swn_dstaddr); + if (ret < 0) { + cifs_dbg(VFS, "%s: failed to store address: %d\n", __func__, ret); + goto unlock; + } + tcon->ses->server->use_swn_dstaddr = true; + + /* + * Unregister to stop receiving notifications for the old IP address. + */ + ret = cifs_swn_unregister(tcon); + if (ret < 0) { + cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n", + __func__, ret); + goto unlock; + } + + /* + * And register to receive notifications for the new IP address now that we have + * stored the new address. + */ + ret = cifs_swn_register(tcon); + if (ret < 0) { + cifs_dbg(VFS, "%s: Failed to register for witness notifications: %d\n", + __func__, ret); + goto unlock; + } + + cifs_signal_cifsd_for_reconnect(tcon->ses->server, false); + +unlock: + cifs_server_unlock(tcon->ses->server); + + return ret; +} + +static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_storage *addr) +{ + struct sockaddr_in *ipv4 = (struct sockaddr_in *)addr; + struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)addr; + + if (addr->ss_family == AF_INET) + cifs_dbg(FYI, "%s: move to %pI4\n", __func__, &ipv4->sin_addr); + else if (addr->ss_family == AF_INET6) + cifs_dbg(FYI, "%s: move to %pI6\n", __func__, &ipv6->sin6_addr); + + return cifs_swn_reconnect(swnreg->tcon, addr); +} + +int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info) +{ + struct cifs_swn_reg *swnreg; + char name[256]; + int type; + + if (info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]) { + int swnreg_id; + + swnreg_id = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]); + mutex_lock(&cifs_swnreg_idr_mutex); + swnreg = idr_find(&cifs_swnreg_idr, swnreg_id); + mutex_unlock(&cifs_swnreg_idr_mutex); + if (swnreg == NULL) { + cifs_dbg(FYI, "%s: registration id %d not found\n", __func__, swnreg_id); + return -EINVAL; + } + } else { + cifs_dbg(FYI, "%s: missing registration id attribute\n", __func__); + return -EINVAL; + } + + if (info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]) { + type = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]); + } else { + cifs_dbg(FYI, "%s: missing notification type attribute\n", __func__); + return -EINVAL; + } + + switch (type) { + case CIFS_SWN_NOTIFICATION_RESOURCE_CHANGE: { + int state; + + if (info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_NAME]) { + nla_strscpy(name, info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_NAME], + sizeof(name)); + } else { + cifs_dbg(FYI, "%s: missing resource name attribute\n", __func__); + return -EINVAL; + } + if (info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]) { + state = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]); + } else { + cifs_dbg(FYI, "%s: missing resource state attribute\n", __func__); + return -EINVAL; + } + return cifs_swn_resource_state_changed(swnreg, name, state); + } + case CIFS_SWN_NOTIFICATION_CLIENT_MOVE: { + struct sockaddr_storage addr; + + if (info->attrs[CIFS_GENL_ATTR_SWN_IP]) { + nla_memcpy(&addr, info->attrs[CIFS_GENL_ATTR_SWN_IP], sizeof(addr)); + } else { + cifs_dbg(FYI, "%s: missing IP address attribute\n", __func__); + return -EINVAL; + } + return cifs_swn_client_move(swnreg, &addr); + } + default: + cifs_dbg(FYI, "%s: unknown notification type %d\n", __func__, type); + break; + } + + return 0; +} + +int cifs_swn_register(struct cifs_tcon *tcon) +{ + struct cifs_swn_reg *swnreg; + int ret; + + swnreg = cifs_get_swn_reg(tcon); + if (IS_ERR(swnreg)) + return PTR_ERR(swnreg); + + ret = cifs_swn_send_register_message(swnreg); + if (ret < 0) { + cifs_dbg(VFS, "%s: Failed to send swn register message: %d\n", __func__, ret); + /* Do not put the swnreg or return error, the echo task will retry */ + } + + return 0; +} + +int cifs_swn_unregister(struct cifs_tcon *tcon) +{ + struct cifs_swn_reg *swnreg; + + mutex_lock(&cifs_swnreg_idr_mutex); + + swnreg = cifs_find_swn_reg(tcon); + if (IS_ERR(swnreg)) { + mutex_unlock(&cifs_swnreg_idr_mutex); + return PTR_ERR(swnreg); + } + + mutex_unlock(&cifs_swnreg_idr_mutex); + + cifs_put_swn_reg(swnreg); + + return 0; +} + +void cifs_swn_dump(struct seq_file *m) +{ + struct cifs_swn_reg *swnreg; + struct sockaddr_in *sa; + struct sockaddr_in6 *sa6; + int id; + + seq_puts(m, "Witness registrations:"); + + mutex_lock(&cifs_swnreg_idr_mutex); + idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) { + seq_printf(m, "\nId: %u Refs: %u Network name: '%s'%s Share name: '%s'%s Ip address: ", + id, kref_read(&swnreg->ref_count), + swnreg->net_name, swnreg->net_name_notify ? "(y)" : "(n)", + swnreg->share_name, swnreg->share_name_notify ? "(y)" : "(n)"); + switch (swnreg->tcon->ses->server->dstaddr.ss_family) { + case AF_INET: + sa = (struct sockaddr_in *) &swnreg->tcon->ses->server->dstaddr; + seq_printf(m, "%pI4", &sa->sin_addr.s_addr); + break; + case AF_INET6: + sa6 = (struct sockaddr_in6 *) &swnreg->tcon->ses->server->dstaddr; + seq_printf(m, "%pI6", &sa6->sin6_addr.s6_addr); + if (sa6->sin6_scope_id) + seq_printf(m, "%%%u", sa6->sin6_scope_id); + break; + default: + seq_puts(m, "(unknown)"); + } + seq_printf(m, "%s", swnreg->ip_notify ? "(y)" : "(n)"); + } + mutex_unlock(&cifs_swnreg_idr_mutex); + seq_puts(m, "\n"); +} + +void cifs_swn_check(void) +{ + struct cifs_swn_reg *swnreg; + int id; + int ret; + + mutex_lock(&cifs_swnreg_idr_mutex); + idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) { + ret = cifs_swn_send_register_message(swnreg); + if (ret < 0) + cifs_dbg(FYI, "%s: Failed to send register message: %d\n", __func__, ret); + } + mutex_unlock(&cifs_swnreg_idr_mutex); +} |