swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f authored by Linus Torvalds on 22 May 2022, 19:52:31 UTC
Linux 5.18
Linux 5.18
Tip revision: 4b0986a
cifs_swn.c
// 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->treeName);
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->treeName, ret);
return ERR_PTR(-EINVAL);
}
share_name = extract_sharename(tcon->treeName);
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->treeName, 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->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);
}
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 */
mutex_lock(&tcon->ses->server->srv_mutex);
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:
mutex_unlock(&tcon->ses->server->srv_mutex);
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);
}