// SPDX-License-Identifier: GPL-2.0-only #include #include #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, }; /* 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, }; 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, }, }; 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);