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 9DEA6C352AA for ; Tue, 1 Oct 2019 21:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 728ED21920 for ; Tue, 1 Oct 2019 21:42:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h80AYzek" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727762AbfJAVmB (ORCPT ); Tue, 1 Oct 2019 17:42:01 -0400 Received: from mail-qk1-f194.google.com ([209.85.222.194]:37952 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726326AbfJAVmA (ORCPT ); Tue, 1 Oct 2019 17:42:00 -0400 Received: by mail-qk1-f194.google.com with SMTP id u186so12836523qkc.5; Tue, 01 Oct 2019 14:42:00 -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=mJEbpnnBACnjKqVJ7ryTqoKmyEa7W0hY6uGaayjFIYA=; b=h80AYzek/0mtKGTG/s6iFgvbhXKJGTvX6PBJ70/+iPeybULGYsNjwDQJM1/sKgG52L 0jh70gaSzstDlldMZCwpZHZDk6pYWLjM9ksE4+xRcNBvO7BtC1OiHplVTErVZ/Bpa/Tv is6mkB5u/RUm9L43cx+DnLF3wAr/7j370Nv5otRPoq5B9VkhCm8eZyrzQylG/5hj0l4E xfwKjXwklg/jWgf3sDGKE5toRQ4fagK7uDBuQfCnrlcJwjuZY4Hg45WLAoCksTpf56RS ul2t4WMwqLfutbcLf5WK3r/TKSRXfR7RiPflLzfRzMtnc7EMKRY+mzjfgOHJbyNFH9dK RJVQ== 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=mJEbpnnBACnjKqVJ7ryTqoKmyEa7W0hY6uGaayjFIYA=; b=WPWy9GcIPXiTN8XN9Am9tgFp483TsRxZrIVRdDLDDNDkBR0hvOFVf6jQnYyri7Hq63 x7qIQZD+09l2Iu2/VsXBBi1geGHhfT55hT93cWYsIt9nDsPnPINm/rcPHNJZFiAHGjZ0 4tQ6xspqyR52eGK4gMpgwg7izyjBrfPmdUrnMkH235Wy59o0WTy6az4rlVJNnHFROuo6 j4hlwiroeSqSSVU4Qf4v2imrQj0raGhIAlApfvfXlGf+Cb/vS2rVXbMqbTlqJ2hBC3Cp NiCnEaLPnmDN/ph49eUh4YbJ8cQM5mcAI9lAPTQZmbcJfTZsgBZXSLO0Xdmyx6d3vABO XTDQ== X-Gm-Message-State: APjAAAWbmI9OCnqiXhECufcBfFpuBL0eZ6bx9/D90WB0TqRdUbidVGXD iDtlMhKKKHHRkgl4+3PEXULBp4Omr80= X-Google-Smtp-Source: APXvYqyvtKcku2+wJzxA5Qewwa8T6dTbMdM6Ab3lnVp5UHSGw3lN2BYrMSdOd9jse2XtuN97Hk26CA== X-Received: by 2002:a05:620a:147:: with SMTP id e7mr285180qkn.227.1569966119391; Tue, 01 Oct 2019 14:41:59 -0700 (PDT) Received: from ebpf00.byteswizards.com ([190.162.109.190]) by smtp.googlemail.com with ESMTPSA id v13sm8559352qtp.61.2019.10.01.14.41.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Oct 2019 14:41:58 -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 V12 2/4] bpf: added new helper bpf_get_ns_current_pid_tgid Date: Tue, 1 Oct 2019 18:41:39 -0300 Message-Id: <20191001214141.6294-3-cneirabustos@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001214141.6294-1-cneirabustos@gmail.com> References: <20191001214141.6294-1-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 | 18 +++++++++++++++++- kernel/bpf/core.c | 1 + kernel/bpf/helpers.c | 36 ++++++++++++++++++++++++++++++++++++ kernel/trace/bpf_trace.c | 2 ++ 5 files changed, 57 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..ea8145d7f897 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2750,6 +2750,21 @@ 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(u64 dev, u64 inum) + * Return + * A 64-bit integer containing the current tgid and pid from current task + * which namespace inode and dev_t matches , and is create as such: + * *current_task*\ **->tgid << 32 \|** + * *current_task*\ **->pid**. + * + * 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 +2877,8 @@ 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 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..8777181d1717 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 +489,37 @@ const struct bpf_func_proto bpf_strtoul_proto = { .arg4_type = ARG_PTR_TO_LONG, }; #endif + +BPF_CALL_2(bpf_get_ns_current_pid_tgid, u64, dev, u64, inum) +{ + struct task_struct *task = current; + struct pid_namespace *pidns; + pid_t pid, tgid; + + if ((u64)(dev_t)dev != dev) + return -EINVAL; + + if (unlikely(!task)) + return -EINVAL; + + pidns = task_active_pid_ns(task); + if (unlikely(!pidns)) + return -ENOENT; + + + if (!ns_match(&pidns->ns, (dev_t)dev, inum)) + return -EINVAL; + + pid = task_pid_nr_ns(task, pidns); + tgid = task_tgid_nr_ns(task, pidns); + + return (u64) tgid << 32 | pid; +} + +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_ANYTHING, + .arg2_type = ARG_ANYTHING, +}; 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