From patchwork Thu Oct 17 15:00:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Carlos Antonio Neira Bustos X-Patchwork-Id: 1178717 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="pwiGsGl7"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46vC5w5FQqz9sPc for ; Fri, 18 Oct 2019 02:00:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406637AbfJQPAs (ORCPT ); Thu, 17 Oct 2019 11:00:48 -0400 Received: from mail-qk1-f194.google.com ([209.85.222.194]:39352 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731768AbfJQPAs (ORCPT ); Thu, 17 Oct 2019 11:00:48 -0400 Received: by mail-qk1-f194.google.com with SMTP id 4so2147032qki.6; Thu, 17 Oct 2019 08:00:47 -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=ibxCrQjjLmKEnH9cIzGG1Bmbb2ACnvCT12kEmqAt8LQ=; b=pwiGsGl7rIUv0+b/wMlbeIx7nGZqr9y+KNFDNvnNl8gN9uKPegFMd94qBF/8qxDjSj 5L87rUzEKh0Eoecb7Mw4POA1LZpVkiQzGYJ9+I/oDUaZeaw5sZpWRfISs2+91BEINibk jMNPuGSzW3rSexTWSeb/Vza7chrclc38Gjs62cmnvSYTXKZhq1Dl7evy40+rJ8W8qTHH ZHsfO3FAdfJE705IWXI4UI5gyOhVf8WlzxGS7+GPWGfriQwfegb+T+v2fboVDUhpNcft V4ZPBF70O2PtXOB0cPGShA+PRiINRWsvU0nwfJInj8FzO7URF+Wrt3zSzcF9jupphJZU 3mPQ== 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=ibxCrQjjLmKEnH9cIzGG1Bmbb2ACnvCT12kEmqAt8LQ=; b=fqTVu3QJNUitkS2g8I5bWTh/ScY+/hlgW2VyUp5YDmx00wzC8GL+tYGtOTc59cmQd4 wg8ZW/UYB5PXR8C/3s2+Lx27ZxHi342KQBnqcrtb84sFUJSO7S3rof705PnVV3IOMniY DPN1omfM5DdIMSUKEibfRdmQWMOPHAwreqL1qRBJWxtAyqdN183bXjflM7NYc2zQJnF4 MZ1i6JxPSbkkHvcf/2GnqfeiOjaTH+R3E4+qUuNM5NEK9G8xwDHU9PfOmhE4FxoxocCy FnQZp602RbxJvGpK/QVHqZvUYTX9XnF29lnWnorFzoFTJcItvTeVVQyyg7A6UXgRqhAl apmA== X-Gm-Message-State: APjAAAWLGsrpvKEgujgooPfN0hes6Vx1PfLS07J1617YMshrWH49tYMu qszbKl9vXoeHI9ZIrduIPo4AQv9Qk9s= X-Google-Smtp-Source: APXvYqwzm90/7C8i0s2JD/pE/RYoPHXCf8Stn+ZQd663SOYVMcOPfdPQRt2gMAEPnMJI+Gz7q7ycUQ== X-Received: by 2002:a37:ac1a:: with SMTP id e26mr3705701qkm.20.1571324446373; Thu, 17 Oct 2019 08:00:46 -0700 (PDT) Received: from ebpf00.byteswizards.com ([190.162.109.190]) by smtp.googlemail.com with ESMTPSA id z20sm1550859qtu.91.2019.10.17.08.00.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Oct 2019 08:00:45 -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 v14 2/5] bpf: added new helper bpf_get_ns_current_pid_tgid Date: Thu, 17 Oct 2019 12:00:29 -0300 Message-Id: <20191017150032.14359-3-cneirabustos@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191017150032.14359-1-cneirabustos@gmail.com> References: <20191017150032.14359-1-cneirabustos@gmail.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 | 20 +++++++++++++++++- kernel/bpf/core.c | 1 + kernel/bpf/helpers.c | 45 ++++++++++++++++++++++++++++++++++++++++ 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 a65c3b0c6935..a17583ae9aa3 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(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size) + * Description + * Returns 0 on success, values for *pid* and *tgid* as seen from the current + * *namespace* will be returned in *nsdata*. + * + * 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 +3627,8 @@ struct bpf_sockopt { __s32 retval; }; +struct bpf_pidns_info { + __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..5477ad984d7c 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 +489,46 @@ const struct bpf_func_proto bpf_strtoul_proto = { .arg4_type = ARG_PTR_TO_LONG, }; #endif + +BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino, + 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 (unlikely((u64)(dev_t)dev != 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)dev, ino)) + 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_ANYTHING, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_UNINIT_MEM, + .arg4_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; }