From patchwork Fri Oct 2 21:49:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 289056 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA8A6C47095 for ; Fri, 2 Oct 2020 21:50:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FB8320719 for ; Fri, 2 Oct 2020 21:50:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601675414; bh=agroEfjCFvs89kt8GMW9uVJKU/eriZ464gflI5f+eEw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JQ2oRCwo9Wime3FrjE2Zqc+DVzqcuc63C/LaEvgPII6lscbiTOxL4V7HBRoDX0NXS gZvzLJtNwTKsU0w1hdNs6QFeYJiyMAOJ2h+l9q6SxcsgFDakg38NI+UKodigktjN0S iFU+Z+bMkWQO+22OhbUztNBMuNJt3V5lnwXDe4fw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725794AbgJBVuI (ORCPT ); Fri, 2 Oct 2020 17:50:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:54734 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725613AbgJBVuE (ORCPT ); Fri, 2 Oct 2020 17:50:04 -0400 Received: from kicinski-fedora-PC1C0HJN.thefacebook.com (unknown [163.114.132.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C6E1B207EA; Fri, 2 Oct 2020 21:50:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601675403; bh=agroEfjCFvs89kt8GMW9uVJKU/eriZ464gflI5f+eEw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k66gBxSeLR0m2Z4RcVdTRH9/fWCVKj6K3P2bj8NgWTUhpC6sQbGmESlY7/xlRSxA3 UPxUwrP/mASEPwGoD63DHbSHMpRuwt9D//V8Fu65abiBzNCGg/ruL5DlzhUb7Mz5a0 VZVazT0o4UmKmQGuHTFsPqTVhAaE2JwRuyVvV0KQ= From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, andrew@lunn.ch, johannes@sipsolutions.net, jiri@resnulli.us, mkubecek@suse.cz, dsahern@kernel.org, pablo@netfilter.org, Jakub Kicinski Subject: [PATCH net-next v3 2/9] genetlink: add small version of ops Date: Fri, 2 Oct 2020 14:49:53 -0700 Message-Id: <20201002215000.1526096-3-kuba@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201002215000.1526096-1-kuba@kernel.org> References: <20201002215000.1526096-1-kuba@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We want to add maxattr and policy back to genl_ops, to enable dumping per command policy to user space. This, however, would cause bloat for all the families with global policies. Introduce smaller version of ops (half the size of genl_ops). Translate these smaller ops into a full blown struct before use in the core. v1: - use struct assignment - put a full copy of the op in struct genl_dumpit_info - s/light/small/ Signed-off-by: Jakub Kicinski Reviewed-by: Johannes Berg --- drivers/thermal/thermal_netlink.c | 2 +- include/net/genetlink.h | 53 +++++++++---- net/netlink/genetlink.c | 127 ++++++++++++++++++++++-------- 3 files changed, 135 insertions(+), 47 deletions(-) diff --git a/drivers/thermal/thermal_netlink.c b/drivers/thermal/thermal_netlink.c index af7b2383e8f6..e9999d5dfdd5 100644 --- a/drivers/thermal/thermal_netlink.c +++ b/drivers/thermal/thermal_netlink.c @@ -545,7 +545,7 @@ static int thermal_genl_cmd_dumpit(struct sk_buff *skb, { struct param p = { .msg = skb }; const struct genl_dumpit_info *info = genl_dumpit_info(cb); - int cmd = info->ops->cmd; + int cmd = info->op.cmd; int ret; void *hdr; diff --git a/include/net/genetlink.h b/include/net/genetlink.h index 5cd9ab0c6bd9..8ea1fc1ed1c7 100644 --- a/include/net/genetlink.h +++ b/include/net/genetlink.h @@ -41,6 +41,8 @@ struct genl_info; * (private) * @ops: the operations supported by this family * @n_ops: number of operations supported by this family + * @small_ops: the small-struct operations supported by this family + * @n_small_ops: number of small-struct operations supported by this family */ struct genl_family { int id; /* private */ @@ -52,6 +54,7 @@ struct genl_family { u8 netnsok:1; u8 parallel_ops:1; u8 n_ops; + u8 n_small_ops; u8 n_mcgrps; const struct nla_policy *policy; int (*pre_doit)(const struct genl_ops *ops, @@ -61,6 +64,7 @@ struct genl_family { struct sk_buff *skb, struct genl_info *info); const struct genl_ops * ops; + const struct genl_small_ops *small_ops; const struct genl_multicast_group *mcgrps; struct module *module; }; @@ -108,23 +112,26 @@ enum genl_validate_flags { }; /** - * struct genl_info - info that is available during dumpit op call - * @family: generic netlink family - for internal genl code usage - * @ops: generic netlink ops - for internal genl code usage - * @attrs: netlink attributes + * struct genl_small_ops - generic netlink operations (small version) + * @cmd: command identifier + * @internal_flags: flags used by the family + * @flags: flags + * @validate: validation flags from enum genl_validate_flags + * @doit: standard command callback + * @dumpit: callback for dumpers + * + * This is a cut-down version of struct genl_ops for users who don't need + * most of the ancillary infra and want to save space. */ -struct genl_dumpit_info { - const struct genl_family *family; - const struct genl_ops *ops; - struct nlattr **attrs; +struct genl_small_ops { + int (*doit)(struct sk_buff *skb, struct genl_info *info); + int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb); + u8 cmd; + u8 internal_flags; + u8 flags; + u8 validate; }; -static inline const struct genl_dumpit_info * -genl_dumpit_info(struct netlink_callback *cb) -{ - return cb->data; -} - /** * struct genl_ops - generic netlink operations * @cmd: command identifier @@ -148,6 +155,24 @@ struct genl_ops { u8 validate; }; +/** + * struct genl_info - info that is available during dumpit op call + * @family: generic netlink family - for internal genl code usage + * @ops: generic netlink ops - for internal genl code usage + * @attrs: netlink attributes + */ +struct genl_dumpit_info { + const struct genl_family *family; + struct genl_ops op; + struct nlattr **attrs; +}; + +static inline const struct genl_dumpit_info * +genl_dumpit_info(struct netlink_callback *cb) +{ + return cb->data; +} + int genl_register_family(struct genl_family *family); int genl_unregister_family(const struct genl_family *family); void genl_notify(const struct genl_family *family, struct sk_buff *skb, diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 4a95e85cf907..42a3c6c7a5ee 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -107,16 +107,75 @@ static const struct genl_family *genl_family_find_byname(char *name) return NULL; } -static const struct genl_ops *genl_get_cmd(u8 cmd, - const struct genl_family *family) +static int genl_get_cmd_cnt(const struct genl_family *family) +{ + return family->n_ops + family->n_small_ops; +} + +static void genl_op_from_full(const struct genl_family *family, + unsigned int i, struct genl_ops *op) +{ + *op = family->ops[i]; +} + +static int genl_get_cmd_full(u8 cmd, const struct genl_family *family, + struct genl_ops *op) { int i; for (i = 0; i < family->n_ops; i++) - if (family->ops[i].cmd == cmd) - return &family->ops[i]; + if (family->ops[i].cmd == cmd) { + genl_op_from_full(family, i, op); + return 0; + } - return NULL; + return -ENOENT; +} + +static void genl_op_from_small(const struct genl_family *family, + unsigned int i, struct genl_ops *op) +{ + memset(op, 0, sizeof(*op)); + op->doit = family->small_ops[i].doit; + op->dumpit = family->small_ops[i].dumpit; + op->cmd = family->small_ops[i].cmd; + op->internal_flags = family->small_ops[i].internal_flags; + op->flags = family->small_ops[i].flags; + op->validate = family->small_ops[i].validate; +} + +static int genl_get_cmd_small(u8 cmd, const struct genl_family *family, + struct genl_ops *op) +{ + int i; + + for (i = 0; i < family->n_small_ops; i++) + if (family->small_ops[i].cmd == cmd) { + genl_op_from_small(family, i, op); + return 0; + } + + return -ENOENT; +} + +static int genl_get_cmd(u8 cmd, const struct genl_family *family, + struct genl_ops *op) +{ + if (!genl_get_cmd_full(cmd, family, op)) + return 0; + return genl_get_cmd_small(cmd, family, op); +} + +static void genl_get_cmd_by_index(unsigned int i, + const struct genl_family *family, + struct genl_ops *op) +{ + if (i < family->n_ops) + genl_op_from_full(family, i, op); + else if (i < family->n_ops + family->n_small_ops) + genl_op_from_small(family, i - family->n_ops, op); + else + WARN_ON_ONCE(1); } static int genl_allocate_reserve_groups(int n_groups, int *first_id) @@ -286,22 +345,25 @@ static void genl_unregister_mc_groups(const struct genl_family *family) static int genl_validate_ops(const struct genl_family *family) { - const struct genl_ops *ops = family->ops; - unsigned int n_ops = family->n_ops; int i, j; - if (WARN_ON(n_ops && !ops)) + if (WARN_ON(family->n_ops && !family->ops) || + WARN_ON(family->n_small_ops && !family->small_ops)) return -EINVAL; - if (!n_ops) - return 0; + for (i = 0; i < genl_get_cmd_cnt(family); i++) { + struct genl_ops op; - for (i = 0; i < n_ops; i++) { - if (ops[i].dumpit == NULL && ops[i].doit == NULL) + genl_get_cmd_by_index(i, family, &op); + if (op.dumpit == NULL && op.doit == NULL) return -EINVAL; - for (j = i + 1; j < n_ops; j++) - if (ops[i].cmd == ops[j].cmd) + for (j = i + 1; j < genl_get_cmd_cnt(family); j++) { + struct genl_ops op2; + + genl_get_cmd_by_index(j, family, &op2); + if (op.cmd == op2.cmd) return -EINVAL; + } } return 0; @@ -524,7 +586,7 @@ static int genl_start(struct netlink_callback *cb) return -ENOMEM; } info->family = ctx->family; - info->ops = ops; + info->op = *ops; info->attrs = attrs; cb->data = info; @@ -546,7 +608,7 @@ static int genl_start(struct netlink_callback *cb) static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { - const struct genl_ops *ops = genl_dumpit_info(cb)->ops; + const struct genl_ops *ops = &genl_dumpit_info(cb)->op; int rc; genl_lock(); @@ -558,7 +620,7 @@ static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) static int genl_lock_done(struct netlink_callback *cb) { const struct genl_dumpit_info *info = genl_dumpit_info(cb); - const struct genl_ops *ops = info->ops; + const struct genl_ops *ops = &info->op; int rc = 0; if (ops->done) { @@ -574,7 +636,7 @@ static int genl_lock_done(struct netlink_callback *cb) static int genl_parallel_done(struct netlink_callback *cb) { const struct genl_dumpit_info *info = genl_dumpit_info(cb); - const struct genl_ops *ops = info->ops; + const struct genl_ops *ops = &info->op; int rc = 0; if (ops->done) @@ -682,9 +744,9 @@ static int genl_family_rcv_msg(const struct genl_family *family, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { - const struct genl_ops *ops; struct net *net = sock_net(skb->sk); struct genlmsghdr *hdr = nlmsg_data(nlh); + struct genl_ops op; int hdrlen; /* this family doesn't exist in this netns */ @@ -695,24 +757,23 @@ static int genl_family_rcv_msg(const struct genl_family *family, if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) return -EINVAL; - ops = genl_get_cmd(hdr->cmd, family); - if (ops == NULL) + if (genl_get_cmd(hdr->cmd, family, &op)) return -EOPNOTSUPP; - if ((ops->flags & GENL_ADMIN_PERM) && + if ((op.flags & GENL_ADMIN_PERM) && !netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; - if ((ops->flags & GENL_UNS_ADMIN_PERM) && + if ((op.flags & GENL_UNS_ADMIN_PERM) && !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) return genl_family_rcv_msg_dumpit(family, skb, nlh, extack, - ops, hdrlen, net); + &op, hdrlen, net); else return genl_family_rcv_msg_doit(family, skb, nlh, extack, - ops, hdrlen, net); + &op, hdrlen, net); } static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, @@ -765,7 +826,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr)) goto nla_put_failure; - if (family->n_ops) { + if (genl_get_cmd_cnt(family)) { struct nlattr *nla_ops; int i; @@ -773,14 +834,16 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, if (nla_ops == NULL) goto nla_put_failure; - for (i = 0; i < family->n_ops; i++) { + for (i = 0; i < genl_get_cmd_cnt(family); i++) { struct nlattr *nest; - const struct genl_ops *ops = &family->ops[i]; - u32 op_flags = ops->flags; + struct genl_ops op; + u32 op_flags; - if (ops->dumpit) + genl_get_cmd_by_index(i, family, &op); + op_flags = op.flags; + if (op.dumpit) op_flags |= GENL_CMD_CAP_DUMP; - if (ops->doit) + if (op.doit) op_flags |= GENL_CMD_CAP_DO; if (family->policy) op_flags |= GENL_CMD_CAP_HASPOL; @@ -789,7 +852,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, if (nest == NULL) goto nla_put_failure; - if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) || + if (nla_put_u32(skb, CTRL_ATTR_OP_ID, op.cmd) || nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags)) goto nla_put_failure;