From patchwork Thu Oct 1 00:05:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 267255 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=-13.6 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,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 562C4C4741F for ; Thu, 1 Oct 2020 00:05:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 171EE2184D for ; Thu, 1 Oct 2020 00:05:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601510732; bh=UK4+gd5MZz9zCWkRgQ9UeM638zg3cKD+jcLbuulNtUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lcQb7mS/KVhNmnPqDnB2unuSBYJ7HXWuaBRiLvCCfL5tTFOAkoCSstJa79+w+s+o+ pfeZYBDtNU8i7noDHYMerIQT+f73E2qZaEzzWNYQ+C/f3XM5u0+NnEoBauIehZ7owu GjBmR3P83b3X7aOI+Jj+BpLKy2SAkOx+CyPo2jIY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731649AbgJAAFa (ORCPT ); Wed, 30 Sep 2020 20:05:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:58632 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731287AbgJAAF3 (ORCPT ); Wed, 30 Sep 2020 20:05:29 -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 372BF2184D; Thu, 1 Oct 2020 00:05:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601510728; bh=UK4+gd5MZz9zCWkRgQ9UeM638zg3cKD+jcLbuulNtUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MXX2eJhkpNKkT7Odd34JNwxLzMZiCE/Et5StOcYvymF5BZYoSiTLFxhcwa4EcMIOK 3uN0QB6AlPeLsvR8fc6XNDUiuF7HDhqjIcl/vUXKFHRwh70ZlE7JhBRBUthT/jr6QR joYg2TT1vbjZA/8KqpNINOtMRtgNDKFzpZvCGDpM= From: Jakub Kicinski To: netdev@vger.kernel.org Cc: andrew@lunn.ch, johannes@sipsolutions.net, jiri@resnulli.us, mkubecek@suse.cz, dsahern@kernel.org, pablo@netfilter.org, Jakub Kicinski Subject: [RFC net-next 3/9] genetlink: add small version of ops Date: Wed, 30 Sep 2020 17:05:12 -0700 Message-Id: <20201001000518.685243-4-kuba@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201001000518.685243-1-kuba@kernel.org> References: <20201001000518.685243-1-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. Signed-off-by: Jakub Kicinski Reviewed-by: Johannes Berg --- include/net/genetlink.h | 25 +++++++++ net/netlink/genetlink.c | 119 ++++++++++++++++++++++++++++++---------- 2 files changed, 116 insertions(+), 28 deletions(-) diff --git a/include/net/genetlink.h b/include/net/genetlink.h index 0033c76ff094..d781f2a240b5 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; }; @@ -125,6 +129,27 @@ genl_dumpit_info(struct netlink_callback *cb) return cb->data; } +/** + * 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_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; +}; + /** * struct genl_ops - generic netlink operations * @cmd: command identifier diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 3a718e327515..38d8f353dba1 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) +{ + memcpy(op, &family->ops[i], sizeof(*op)); +} + +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_light(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_light(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_light(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_light(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_light(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; @@ -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;