diff options
Diffstat (limited to 'fs/cifs/cifs_swn.c')
-rw-r--r-- | fs/cifs/cifs_swn.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/fs/cifs/cifs_swn.c b/fs/cifs/cifs_swn.c new file mode 100644 index 000000000000..c0af03955d0c --- /dev/null +++ b/fs/cifs/cifs_swn.c @@ -0,0 +1,421 @@ +// 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; + 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; + + 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; + } + + 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 LANMAN: + case NTLM: + 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 funciton 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->treeName); + if (IS_ERR_OR_NULL(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->treeName, ret); + return NULL; + } + + share_name = extract_sharename(tcon->treeName); + if (IS_ERR_OR_NULL(share_name)) { + int ret; + + ret = PTR_ERR(net_name); + cifs_dbg(VFS, "%s: failed to extract share name from target '%s': %d\n", + __func__, tcon->treeName, ret); + kfree(net_name); + return NULL; + } + + 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; + } + + mutex_unlock(&cifs_swnreg_idr_mutex); + + 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 NULL; +} + +/* + * 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)) { + return reg; + } else if (reg != NULL) { + kref_get(®->ref_count); + 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->treeName); + 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->treeName); + 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); +} + +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 (swnreg == NULL) { + mutex_unlock(&cifs_swnreg_idr_mutex); + return -EEXIST; + } + + mutex_unlock(&cifs_swnreg_idr_mutex); + + cifs_put_swn_reg(swnreg); + + return 0; +} |