diff options
Diffstat (limited to 'net/ethtool/netlink.c')
| -rw-r--r-- | net/ethtool/netlink.c | 729 |
1 files changed, 729 insertions, 0 deletions
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c new file mode 100644 index 000000000000..180c194fab07 --- /dev/null +++ b/net/ethtool/netlink.c @@ -0,0 +1,729 @@ +// 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, ðtool_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, ðtool_genl_family, 0, + cmd); +} + +static int ethnl_multicast(struct sk_buff *skb, struct net_device *dev) +{ + return genlmsg_multicast_netns(ðtool_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] = ðnl_strset_request_ops, + [ETHTOOL_MSG_LINKINFO_GET] = ðnl_linkinfo_request_ops, + [ETHTOOL_MSG_LINKMODES_GET] = ðnl_linkmodes_request_ops, + [ETHTOOL_MSG_LINKSTATE_GET] = ðnl_linkstate_request_ops, + [ETHTOOL_MSG_DEBUG_GET] = ðnl_debug_request_ops, + [ETHTOOL_MSG_WOL_GET] = ðnl_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, + ðtool_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] = ðnl_linkinfo_request_ops, + [ETHTOOL_MSG_LINKMODES_NTF] = ðnl_linkmodes_request_ops, + [ETHTOOL_MSG_DEBUG_NTF] = ðnl_debug_request_ops, + [ETHTOOL_MSG_WOL_NTF] = ðnl_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(ðtool_genl_family); + if (WARN(ret < 0, "ethtool: genetlink family registration failed")) + return ret; + ethnl_ok = true; + + return 0; +} + +subsys_initcall(ethnl_init); |