linux/net/ethtool/netlink.c

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// 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;
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;
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;
if (tb[ETHTOOL_A_HEADER_FLAGS])
req_info->flags = nla_get_u32(tb[ETHTOOL_A_HEADER_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);