linux_dsm_epyc7002/net/ethtool/netlink.c
Michal Kubecek 2363d73a2f ethtool: reject unrecognized request flags
As pointed out by Jakub Kicinski, we ethtool netlink code should respond
with an error if request head has flags set which are not recognized by
kernel, either as a mistake or because it expects functionality introduced
in later kernel versions.

To avoid unnecessary roundtrips, use extack cookie to provide the
information about supported request flags.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-16 02:04:24 -07:00

738 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <net/sock.h>
#include <linux/ethtool_netlink.h>
#include "netlink.h"
static struct genl_family ethtool_genl_family;
static bool ethnl_ok __read_mostly;
static u32 ethnl_bcast_seq;
static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
[ETHTOOL_A_HEADER_UNSPEC] = { .type = NLA_REJECT },
[ETHTOOL_A_HEADER_DEV_INDEX] = { .type = NLA_U32 },
[ETHTOOL_A_HEADER_DEV_NAME] = { .type = NLA_NUL_STRING,
.len = ALTIFNAMSIZ - 1 },
[ETHTOOL_A_HEADER_FLAGS] = { .type = NLA_U32 },
};
/**
* ethnl_parse_header() - parse request header
* @req_info: structure to put results into
* @header: nest attribute with request header
* @net: request netns
* @extack: netlink extack for error reporting
* @require_dev: fail if no device identified in header
*
* Parse request header in nested attribute @nest and puts results into
* the structure pointed to by @req_info. Extack from @info is used for error
* reporting. If req_info->dev is not null on return, reference to it has
* been taken. If error is returned, *req_info is null initialized and no
* reference is held.
*
* Return: 0 on success or negative error code
*/
int ethnl_parse_header(struct ethnl_req_info *req_info,
const struct nlattr *header, struct net *net,
struct netlink_ext_ack *extack, bool require_dev)
{
struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1];
const struct nlattr *devname_attr;
struct net_device *dev = NULL;
u32 flags = 0;
int ret;
if (!header) {
NL_SET_ERR_MSG(extack, "request header missing");
return -EINVAL;
}
ret = nla_parse_nested(tb, ETHTOOL_A_HEADER_MAX, header,
ethnl_header_policy, extack);
if (ret < 0)
return ret;
if (tb[ETHTOOL_A_HEADER_FLAGS]) {
flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]);
if (flags & ~ETHTOOL_FLAG_ALL) {
NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_HEADER_FLAGS],
"unrecognized request flags");
nl_set_extack_cookie_u32(extack, ETHTOOL_FLAG_ALL);
return -EOPNOTSUPP;
}
}
devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME];
if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) {
u32 ifindex = nla_get_u32(tb[ETHTOOL_A_HEADER_DEV_INDEX]);
dev = dev_get_by_index(net, ifindex);
if (!dev) {
NL_SET_ERR_MSG_ATTR(extack,
tb[ETHTOOL_A_HEADER_DEV_INDEX],
"no device matches ifindex");
return -ENODEV;
}
/* if both ifindex and ifname are passed, they must match */
if (devname_attr &&
strncmp(dev->name, nla_data(devname_attr), IFNAMSIZ)) {
dev_put(dev);
NL_SET_ERR_MSG_ATTR(extack, header,
"ifindex and name do not match");
return -ENODEV;
}
} else if (devname_attr) {
dev = dev_get_by_name(net, nla_data(devname_attr));
if (!dev) {
NL_SET_ERR_MSG_ATTR(extack, devname_attr,
"no device matches name");
return -ENODEV;
}
} else if (require_dev) {
NL_SET_ERR_MSG_ATTR(extack, header,
"neither ifindex nor name specified");
return -EINVAL;
}
if (dev && !netif_device_present(dev)) {
dev_put(dev);
NL_SET_ERR_MSG(extack, "device not present");
return -ENODEV;
}
req_info->dev = dev;
req_info->flags = flags;
return 0;
}
/**
* ethnl_fill_reply_header() - Put common header into a reply message
* @skb: skb with the message
* @dev: network device to describe in header
* @attrtype: attribute type to use for the nest
*
* Create a nested attribute with attributes describing given network device.
*
* Return: 0 on success, error value (-EMSGSIZE only) on error
*/
int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
u16 attrtype)
{
struct nlattr *nest;
if (!dev)
return 0;
nest = nla_nest_start(skb, attrtype);
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, ETHTOOL_A_HEADER_DEV_INDEX, (u32)dev->ifindex) ||
nla_put_string(skb, ETHTOOL_A_HEADER_DEV_NAME, dev->name))
goto nla_put_failure;
/* If more attributes are put into reply header, ethnl_header_size()
* must be updated to account for them.
*/
nla_nest_end(skb, nest);
return 0;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
/**
* ethnl_reply_init() - Create skb for a reply and fill device identification
* @payload: payload length (without netlink and genetlink header)
* @dev: device the reply is about (may be null)
* @cmd: ETHTOOL_MSG_* message type for reply
* @hdr_attrtype: attribute type for common header
* @info: genetlink info of the received packet we respond to
* @ehdrp: place to store payload pointer returned by genlmsg_new()
*
* Return: pointer to allocated skb on success, NULL on error
*/
struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
u16 hdr_attrtype, struct genl_info *info,
void **ehdrp)
{
struct sk_buff *skb;
skb = genlmsg_new(payload, GFP_KERNEL);
if (!skb)
goto err;
*ehdrp = genlmsg_put_reply(skb, info, &ethtool_genl_family, 0, cmd);
if (!*ehdrp)
goto err_free;
if (dev) {
int ret;
ret = ethnl_fill_reply_header(skb, dev, hdr_attrtype);
if (ret < 0)
goto err_free;
}
return skb;
err_free:
nlmsg_free(skb);
err:
if (info)
GENL_SET_ERR_MSG(info, "failed to setup reply message");
return NULL;
}
static void *ethnl_bcastmsg_put(struct sk_buff *skb, u8 cmd)
{
return genlmsg_put(skb, 0, ++ethnl_bcast_seq, &ethtool_genl_family, 0,
cmd);
}
static int ethnl_multicast(struct sk_buff *skb, struct net_device *dev)
{
return genlmsg_multicast_netns(&ethtool_genl_family, dev_net(dev), skb,
0, ETHNL_MCGRP_MONITOR, GFP_KERNEL);
}
/* GET request helpers */
/**
* struct ethnl_dump_ctx - context structure for generic dumpit() callback
* @ops: request ops of currently processed message type
* @req_info: parsed request header of processed request
* @reply_data: data needed to compose the reply
* @pos_hash: saved iteration position - hashbucket
* @pos_idx: saved iteration position - index
*
* These parameters are kept in struct netlink_callback as context preserved
* between iterations. They are initialized by ethnl_default_start() and used
* in ethnl_default_dumpit() and ethnl_default_done().
*/
struct ethnl_dump_ctx {
const struct ethnl_request_ops *ops;
struct ethnl_req_info *req_info;
struct ethnl_reply_data *reply_data;
int pos_hash;
int pos_idx;
};
static const struct ethnl_request_ops *
ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
[ETHTOOL_MSG_STRSET_GET] = &ethnl_strset_request_ops,
[ETHTOOL_MSG_LINKINFO_GET] = &ethnl_linkinfo_request_ops,
[ETHTOOL_MSG_LINKMODES_GET] = &ethnl_linkmodes_request_ops,
[ETHTOOL_MSG_LINKSTATE_GET] = &ethnl_linkstate_request_ops,
[ETHTOOL_MSG_DEBUG_GET] = &ethnl_debug_request_ops,
[ETHTOOL_MSG_WOL_GET] = &ethnl_wol_request_ops,
};
static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
{
return (struct ethnl_dump_ctx *)cb->ctx;
}
/**
* ethnl_default_parse() - Parse request message
* @req_info: pointer to structure to put data into
* @nlhdr: pointer to request message header
* @net: request netns
* @request_ops: struct request_ops for request type
* @extack: netlink extack for error reporting
* @require_dev: fail if no device identified in header
*
* Parse universal request header and call request specific ->parse_request()
* callback (if defined) to parse the rest of the message.
*
* Return: 0 on success or negative error code
*/
static int ethnl_default_parse(struct ethnl_req_info *req_info,
const struct nlmsghdr *nlhdr, struct net *net,
const struct ethnl_request_ops *request_ops,
struct netlink_ext_ack *extack, bool require_dev)
{
struct nlattr **tb;
int ret;
tb = kmalloc_array(request_ops->max_attr + 1, sizeof(tb[0]),
GFP_KERNEL);
if (!tb)
return -ENOMEM;
ret = nlmsg_parse(nlhdr, GENL_HDRLEN, tb, request_ops->max_attr,
request_ops->request_policy, extack);
if (ret < 0)
goto out;
ret = ethnl_parse_header(req_info, tb[request_ops->hdr_attr], net,
extack, require_dev);
if (ret < 0)
goto out;
if (request_ops->parse_request) {
ret = request_ops->parse_request(req_info, tb, extack);
if (ret < 0)
goto out;
}
ret = 0;
out:
kfree(tb);
return ret;
}
/**
* ethnl_init_reply_data() - Initialize reply data for GET request
* @reply_data: pointer to embedded struct ethnl_reply_data
* @ops: instance of struct ethnl_request_ops describing the layout
* @dev: network device to initialize the reply for
*
* Fills the reply data part with zeros and sets the dev member. Must be called
* before calling the ->fill_reply() callback (for each iteration when handling
* dump requests).
*/
static void ethnl_init_reply_data(struct ethnl_reply_data *reply_data,
const struct ethnl_request_ops *ops,
struct net_device *dev)
{
memset(reply_data, 0, ops->reply_data_size);
reply_data->dev = dev;
}
/* default ->doit() handler for GET type requests */
static int ethnl_default_doit(struct sk_buff *skb, struct genl_info *info)
{
struct ethnl_reply_data *reply_data = NULL;
struct ethnl_req_info *req_info = NULL;
const u8 cmd = info->genlhdr->cmd;
const struct ethnl_request_ops *ops;
struct sk_buff *rskb;
void *reply_payload;
int reply_len;
int ret;
ops = ethnl_default_requests[cmd];
if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", cmd))
return -EOPNOTSUPP;
req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
if (!req_info)
return -ENOMEM;
reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
if (!reply_data) {
kfree(req_info);
return -ENOMEM;
}
ret = ethnl_default_parse(req_info, info->nlhdr, genl_info_net(info), ops,
info->extack, !ops->allow_nodev_do);
if (ret < 0)
goto err_dev;
ethnl_init_reply_data(reply_data, ops, req_info->dev);
rtnl_lock();
ret = ops->prepare_data(req_info, reply_data, info);
rtnl_unlock();
if (ret < 0)
goto err_cleanup;
ret = ops->reply_size(req_info, reply_data);
if (ret < 0)
goto err_cleanup;
reply_len = ret;
ret = -ENOMEM;
rskb = ethnl_reply_init(reply_len, req_info->dev, ops->reply_cmd,
ops->hdr_attr, info, &reply_payload);
if (!rskb)
goto err_cleanup;
ret = ops->fill_reply(rskb, req_info, reply_data);
if (ret < 0)
goto err_msg;
if (ops->cleanup_data)
ops->cleanup_data(reply_data);
genlmsg_end(rskb, reply_payload);
if (req_info->dev)
dev_put(req_info->dev);
kfree(reply_data);
kfree(req_info);
return genlmsg_reply(rskb, info);
err_msg:
WARN_ONCE(ret == -EMSGSIZE, "calculated message payload length (%d) not sufficient\n", reply_len);
nlmsg_free(rskb);
err_cleanup:
if (ops->cleanup_data)
ops->cleanup_data(reply_data);
err_dev:
if (req_info->dev)
dev_put(req_info->dev);
kfree(reply_data);
kfree(req_info);
return ret;
}
static int ethnl_default_dump_one(struct sk_buff *skb, struct net_device *dev,
const struct ethnl_dump_ctx *ctx)
{
int ret;
ethnl_init_reply_data(ctx->reply_data, ctx->ops, dev);
rtnl_lock();
ret = ctx->ops->prepare_data(ctx->req_info, ctx->reply_data, NULL);
rtnl_unlock();
if (ret < 0)
goto out;
ret = ethnl_fill_reply_header(skb, dev, ctx->ops->hdr_attr);
if (ret < 0)
goto out;
ret = ctx->ops->fill_reply(skb, ctx->req_info, ctx->reply_data);
out:
if (ctx->ops->cleanup_data)
ctx->ops->cleanup_data(ctx->reply_data);
ctx->reply_data->dev = NULL;
return ret;
}
/* Default ->dumpit() handler for GET requests. Device iteration copied from
* rtnl_dump_ifinfo(); we have to be more careful about device hashtable
* persistence as we cannot guarantee to hold RTNL lock through the whole
* function as rtnetnlink does.
*/
static int ethnl_default_dumpit(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
struct net *net = sock_net(skb->sk);
int s_idx = ctx->pos_idx;
int h, idx = 0;
int ret = 0;
void *ehdr;
rtnl_lock();
for (h = ctx->pos_hash; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
struct hlist_head *head;
struct net_device *dev;
unsigned int seq;
head = &net->dev_index_head[h];
restart_chain:
seq = net->dev_base_seq;
cb->seq = seq;
idx = 0;
hlist_for_each_entry(dev, head, index_hlist) {
if (idx < s_idx)
goto cont;
dev_hold(dev);
rtnl_unlock();
ehdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
&ethtool_genl_family, 0,
ctx->ops->reply_cmd);
if (!ehdr) {
dev_put(dev);
ret = -EMSGSIZE;
goto out;
}
ret = ethnl_default_dump_one(skb, dev, ctx);
dev_put(dev);
if (ret < 0) {
genlmsg_cancel(skb, ehdr);
if (ret == -EOPNOTSUPP)
goto lock_and_cont;
if (likely(skb->len))
ret = skb->len;
goto out;
}
genlmsg_end(skb, ehdr);
lock_and_cont:
rtnl_lock();
if (net->dev_base_seq != seq) {
s_idx = idx + 1;
goto restart_chain;
}
cont:
idx++;
}
}
rtnl_unlock();
out:
ctx->pos_hash = h;
ctx->pos_idx = idx;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
return ret;
}
/* generic ->start() handler for GET requests */
static int ethnl_default_start(struct netlink_callback *cb)
{
struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
struct ethnl_reply_data *reply_data;
const struct ethnl_request_ops *ops;
struct ethnl_req_info *req_info;
struct genlmsghdr *ghdr;
int ret;
BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
ghdr = nlmsg_data(cb->nlh);
ops = ethnl_default_requests[ghdr->cmd];
if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", ghdr->cmd))
return -EOPNOTSUPP;
req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
if (!req_info)
return -ENOMEM;
reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
if (!reply_data) {
ret = -ENOMEM;
goto free_req_info;
}
ret = ethnl_default_parse(req_info, cb->nlh, sock_net(cb->skb->sk), ops,
cb->extack, false);
if (req_info->dev) {
/* We ignore device specification in dump requests but as the
* same parser as for non-dump (doit) requests is used, it
* would take reference to the device if it finds one
*/
dev_put(req_info->dev);
req_info->dev = NULL;
}
if (ret < 0)
goto free_reply_data;
ctx->ops = ops;
ctx->req_info = req_info;
ctx->reply_data = reply_data;
ctx->pos_hash = 0;
ctx->pos_idx = 0;
return 0;
free_reply_data:
kfree(reply_data);
free_req_info:
kfree(req_info);
return ret;
}
/* default ->done() handler for GET requests */
static int ethnl_default_done(struct netlink_callback *cb)
{
struct ethnl_dump_ctx *ctx = ethnl_dump_context(cb);
kfree(ctx->reply_data);
kfree(ctx->req_info);
return 0;
}
static const struct ethnl_request_ops *
ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
[ETHTOOL_MSG_LINKINFO_NTF] = &ethnl_linkinfo_request_ops,
[ETHTOOL_MSG_LINKMODES_NTF] = &ethnl_linkmodes_request_ops,
[ETHTOOL_MSG_DEBUG_NTF] = &ethnl_debug_request_ops,
[ETHTOOL_MSG_WOL_NTF] = &ethnl_wol_request_ops,
};
/* default notification handler */
static void ethnl_default_notify(struct net_device *dev, unsigned int cmd,
const void *data)
{
struct ethnl_reply_data *reply_data;
const struct ethnl_request_ops *ops;
struct ethnl_req_info *req_info;
struct sk_buff *skb;
void *reply_payload;
int reply_len;
int ret;
if (WARN_ONCE(cmd > ETHTOOL_MSG_KERNEL_MAX ||
!ethnl_default_notify_ops[cmd],
"unexpected notification type %u\n", cmd))
return;
ops = ethnl_default_notify_ops[cmd];
req_info = kzalloc(ops->req_info_size, GFP_KERNEL);
if (!req_info)
return;
reply_data = kmalloc(ops->reply_data_size, GFP_KERNEL);
if (!reply_data) {
kfree(req_info);
return;
}
req_info->dev = dev;
req_info->flags |= ETHTOOL_FLAG_COMPACT_BITSETS;
ethnl_init_reply_data(reply_data, ops, dev);
ret = ops->prepare_data(req_info, reply_data, NULL);
if (ret < 0)
goto err_cleanup;
ret = ops->reply_size(req_info, reply_data);
if (ret < 0)
goto err_cleanup;
reply_len = ret;
ret = -ENOMEM;
skb = genlmsg_new(reply_len, GFP_KERNEL);
if (!skb)
goto err_cleanup;
reply_payload = ethnl_bcastmsg_put(skb, cmd);
if (!reply_payload)
goto err_skb;
ret = ethnl_fill_reply_header(skb, dev, ops->hdr_attr);
if (ret < 0)
goto err_msg;
ret = ops->fill_reply(skb, req_info, reply_data);
if (ret < 0)
goto err_msg;
if (ops->cleanup_data)
ops->cleanup_data(reply_data);
genlmsg_end(skb, reply_payload);
kfree(reply_data);
kfree(req_info);
ethnl_multicast(skb, dev);
return;
err_msg:
WARN_ONCE(ret == -EMSGSIZE,
"calculated message payload length (%d) not sufficient\n",
reply_len);
err_skb:
nlmsg_free(skb);
err_cleanup:
if (ops->cleanup_data)
ops->cleanup_data(reply_data);
kfree(reply_data);
kfree(req_info);
return;
}
/* notifications */
typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
const void *data);
static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
[ETHTOOL_MSG_LINKINFO_NTF] = ethnl_default_notify,
[ETHTOOL_MSG_LINKMODES_NTF] = ethnl_default_notify,
[ETHTOOL_MSG_DEBUG_NTF] = ethnl_default_notify,
[ETHTOOL_MSG_WOL_NTF] = ethnl_default_notify,
};
void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
{
if (unlikely(!ethnl_ok))
return;
ASSERT_RTNL();
if (likely(cmd < ARRAY_SIZE(ethnl_notify_handlers) &&
ethnl_notify_handlers[cmd]))
ethnl_notify_handlers[cmd](dev, cmd, data);
else
WARN_ONCE(1, "notification %u not implemented (dev=%s)\n",
cmd, netdev_name(dev));
}
EXPORT_SYMBOL(ethtool_notify);
/* genetlink setup */
static const struct genl_ops ethtool_genl_ops[] = {
{
.cmd = ETHTOOL_MSG_STRSET_GET,
.doit = ethnl_default_doit,
.start = ethnl_default_start,
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
{
.cmd = ETHTOOL_MSG_LINKINFO_GET,
.doit = ethnl_default_doit,
.start = ethnl_default_start,
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
{
.cmd = ETHTOOL_MSG_LINKINFO_SET,
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_linkinfo,
},
{
.cmd = ETHTOOL_MSG_LINKMODES_GET,
.doit = ethnl_default_doit,
.start = ethnl_default_start,
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
{
.cmd = ETHTOOL_MSG_LINKMODES_SET,
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_linkmodes,
},
{
.cmd = ETHTOOL_MSG_LINKSTATE_GET,
.doit = ethnl_default_doit,
.start = ethnl_default_start,
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
{
.cmd = ETHTOOL_MSG_DEBUG_GET,
.doit = ethnl_default_doit,
.start = ethnl_default_start,
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
{
.cmd = ETHTOOL_MSG_DEBUG_SET,
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_debug,
},
{
.cmd = ETHTOOL_MSG_WOL_GET,
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_default_doit,
.start = ethnl_default_start,
.dumpit = ethnl_default_dumpit,
.done = ethnl_default_done,
},
{
.cmd = ETHTOOL_MSG_WOL_SET,
.flags = GENL_UNS_ADMIN_PERM,
.doit = ethnl_set_wol,
},
};
static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
[ETHNL_MCGRP_MONITOR] = { .name = ETHTOOL_MCGRP_MONITOR_NAME },
};
static struct genl_family ethtool_genl_family = {
.name = ETHTOOL_GENL_NAME,
.version = ETHTOOL_GENL_VERSION,
.netnsok = true,
.parallel_ops = true,
.ops = ethtool_genl_ops,
.n_ops = ARRAY_SIZE(ethtool_genl_ops),
.mcgrps = ethtool_nl_mcgrps,
.n_mcgrps = ARRAY_SIZE(ethtool_nl_mcgrps),
};
/* module setup */
static int __init ethnl_init(void)
{
int ret;
ret = genl_register_family(&ethtool_genl_family);
if (WARN(ret < 0, "ethtool: genetlink family registration failed"))
return ret;
ethnl_ok = true;
return 0;
}
subsys_initcall(ethnl_init);