From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 3D34AC47404 for ; Wed, 9 Oct 2019 15:26:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0955220679 for ; Wed, 9 Oct 2019 15:26:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UuQPXmfc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731671AbfJIP0t (ORCPT ); Wed, 9 Oct 2019 11:26:49 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:39242 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729644AbfJIP0t (ORCPT ); Wed, 9 Oct 2019 11:26:49 -0400 Received: by mail-qt1-f193.google.com with SMTP id n7so3982796qtb.6; Wed, 09 Oct 2019 08:26:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gLrccfQSPN88or4knKZ/oRltVurvWLGNIQNyDLr0FI8=; b=UuQPXmfcvH+zzw+BI1BGgQg5eQ4kugkIN4ete++I1hWLzUur6jRwweIgwDk9COApju q3Rny+Kt8rwTyL/oVBjnN3zbhvu2vZelJF+MpLJdXSMltJllg6y2I0YACw4K2z4fiRqu W9ZvyjdmW8HnYyYH3xgaDxrg9DpWk+0yYcKgG3XKAzhvVr48yeu37ziN1kVyV4dCXp4d ETknAwq7CeSpRZPbgwBd+3nGhoSM0CLj60A+C7kZwhnoBcJjzMaoYZ9iYBVw0DQvD80R f0aDYKko0CNzj9LgagmrQJiCg+hPplUn8tIZmYzRybf2I2HVpwTfuli91E8/l69nCLq1 jkWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gLrccfQSPN88or4knKZ/oRltVurvWLGNIQNyDLr0FI8=; b=fViTs1sQ8CbDsKypBX+vdvhH8I4LH7GeS12RSWQV7bHC1El4g77Mg5FVE1bTM4cw+S GX4rpaT1/zuj7f+hVNvseF1NzOGE5J1K7ysvgDAtYefRF7M+ArAJBiOL8m7PHFGPdIGn 82pGjXVc4dvIwOdKXU0rTjkBOU5hlWb4wumDidLPoIzsEQeqXra/KPZ24C+nNJunSA1N 2lVU4MZCato9IYI/1/F4d5qtOrls1oQXxw7L9T1AJIWi1mlrzPCdtIe4MangZ49Yx14A WsEF70oLtmby8ZfuAGZFBG6fjd5r5BvyLCFubCGGzkBVUR9AOm58XQDq48+uOyS9aDPC sZEA== X-Gm-Message-State: APjAAAVe53xreeiHXc4i9OoQc9qd2X/bQjmUZCfHyUOUn2GuPwM1r8mj 5KlbX71SWkpey6H6ehNh9+bjGUExIJE= X-Google-Smtp-Source: APXvYqyW/c0Jf6ELYYvxJ6woASryeA3+IxoX0qqDSRG7VcW2IKpMy8vgGmmT6FRnjZoEeO1ti/4RnQ== X-Received: by 2002:a05:6214:3ce:: with SMTP id ce14mr4108090qvb.174.1570634807277; Wed, 09 Oct 2019 08:26:47 -0700 (PDT) Received: from ebpf00.byteswizards.com ([190.162.109.190]) by smtp.googlemail.com with ESMTPSA id l189sm1049895qke.69.2019.10.09.08.26.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Oct 2019 08:26:46 -0700 (PDT) From: Carlos Neira To: netdev@vger.kernel.org Cc: yhs@fb.com, ebiederm@xmission.com, brouer@redhat.com, bpf@vger.kernel.org, cneirabustos@gmail.com Subject: [PATCH v13 2/4] bpf: added new helper bpf_get_ns_current_pid_tgid Date: Wed, 9 Oct 2019 12:26:30 -0300 Message-Id: <20191009152632.14218-3-cneirabustos@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191009152632.14218-1-cneirabustos@gmail.com> References: <20191009152632.14218-1-cneirabustos@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org New bpf helper bpf_get_ns_current_pid_tgid, This helper will return pid and tgid from current task which namespace matches dev_t and inode number provided, this will allows us to instrument a process inside a container. Signed-off-by: Carlos Neira --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 22 +++++++++++++++++++- kernel/bpf/core.c | 1 + kernel/bpf/helpers.c | 43 ++++++++++++++++++++++++++++++++++++++++ kernel/trace/bpf_trace.c | 2 ++ 5 files changed, 68 insertions(+), 1 deletion(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 5b9d22338606..231001475504 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1055,6 +1055,7 @@ extern const struct bpf_func_proto bpf_get_local_storage_proto; extern const struct bpf_func_proto bpf_strtol_proto; extern const struct bpf_func_proto bpf_strtoul_proto; extern const struct bpf_func_proto bpf_tcp_sock_proto; +extern const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto; /* Shared helpers among cBPF and eBPF. */ void bpf_user_rnd_init_once(void); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 77c6be96d676..6ad3f2abf00d 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2750,6 +2750,19 @@ union bpf_attr { * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies * * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 + * + * u64 bpf_get_ns_current_pid_tgid(struct *bpf_pidns_info, u32 size) + * Return + * 0 on success, values for pid and tgid from nsinfo will be as seen + * from the namespace that matches dev and inum from nsinfo. + * + * On failure, the returned value is one of the following: + * + * **-EINVAL** if dev and inum supplied don't match dev_t and inode number + * with nsfs of current task, or if dev conversion to dev_t lost high bits. + * + * **-ENOENT** if /proc/self/ns does not exists. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2862,7 +2875,8 @@ union bpf_attr { FN(sk_storage_get), \ FN(sk_storage_delete), \ FN(send_signal), \ - FN(tcp_gen_syncookie), + FN(tcp_gen_syncookie), \ + FN(get_ns_current_pid_tgid), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -3613,4 +3627,10 @@ struct bpf_sockopt { __s32 retval; }; +struct bpf_pidns_info { + __u64 dev; + __u64 inum; + __u32 pid; + __u32 tgid; +}; #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 66088a9e9b9e..b2fd5358f472 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2042,6 +2042,7 @@ const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; const struct bpf_func_proto bpf_get_current_comm_proto __weak; const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; const struct bpf_func_proto bpf_get_local_storage_proto __weak; +const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak; const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) { diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 5e28718928ca..78a1ce7726aa 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -11,6 +11,8 @@ #include #include #include +#include +#include #include "../../lib/kstrtox.h" @@ -487,3 +489,44 @@ const struct bpf_func_proto bpf_strtoul_proto = { .arg4_type = ARG_PTR_TO_LONG, }; #endif + +BPF_CALL_2(bpf_get_ns_current_pid_tgid, struct bpf_pidns_info *, nsdata, u32, + size) +{ + struct task_struct *task = current; + struct pid_namespace *pidns; + int err = -EINVAL; + + if (unlikely(size != sizeof(struct bpf_pidns_info))) + goto clear; + + if ((u64)(dev_t)nsdata->dev != nsdata->dev) + goto clear; + + if (unlikely(!task)) + goto clear; + + pidns = task_active_pid_ns(task); + if (unlikely(!pidns)) { + err = -ENOENT; + goto clear; + } + + if (!ns_match(&pidns->ns, (dev_t)nsdata->dev, nsdata->inum)) + goto clear; + + nsdata->pid = task_pid_nr_ns(task, pidns); + nsdata->tgid = task_tgid_nr_ns(task, pidns); + return 0; +clear: + memset((void *)nsdata, 0, (size_t) size); + return err; +} + +const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = { + .func = bpf_get_ns_current_pid_tgid, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_UNINIT_MEM, + .arg2_type = ARG_CONST_SIZE, +}; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 44bd08f2443b..32331a1dcb6d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -735,6 +735,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) #endif case BPF_FUNC_send_signal: return &bpf_send_signal_proto; + case BPF_FUNC_get_ns_current_pid_tgid: + return &bpf_get_ns_current_pid_tgid_proto; default: return NULL; } -- 2.20.1