From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EBE37DDB6; Tue, 5 Sep 2023 21:37:40 +0000 (UTC) Received: from out-213.mta0.migadu.com (out-213.mta0.migadu.com [91.218.175.213]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41FFDE4A; Tue, 5 Sep 2023 14:37:33 -0700 (PDT) Message-ID: <76316157-7221-e1d6-4e3c-2f1efb6e6230@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1693949851; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CgXDiSweGrzZb5uC0LdbKTUevgSBi9vuGJu5ieT3xL8=; b=kCW4UKlDbumIrbWAAWQLxz1Yi7bkqxK/PYWDB8G7QyxgwWbMdE3TsXa0BzSAgq9IEfWKQM 6GBZ8oezNzpyIRbYXRUvgPuEnfWJvhyig3lWtCzFhtflqqjDWVdm/htLrn+LVQDJ0uIeC0 mIK7DB6Dtj1iWLvVzl8qtWjQ2kweMcs= Date: Tue, 5 Sep 2023 14:37:27 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v3 3/9] bpf: Add bpf_sock_addr_set_unix_addr() to allow writing unix sockaddr from bpf Content-Language: en-US To: Daan De Meyer Cc: kernel-team@meta.com, netdev@vger.kernel.org, bpf@vger.kernel.org References: <20230831153455.1867110-1-daan.j.demeyer@gmail.com> <20230831153455.1867110-4-daan.j.demeyer@gmail.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau In-Reply-To: <20230831153455.1867110-4-daan.j.demeyer@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 8/31/23 8:34 AM, Daan De Meyer wrote: > As prep for adding unix socket support to the cgroup sockaddr hooks, > let's add a kfunc bpf_sock_addr_set_unix_addr() that allows modifying a sockaddr > from bpf. While this is already possible for AF_INET and AF_INET6, we'll > need this kfunc when we add unix socket support since modifying the > address for those requires modifying both the address and the sockaddr > length. > > Signed-off-by: Daan De Meyer > --- > kernel/bpf/btf.c | 1 + > net/core/filter.c | 32 +++++++++++++++++++++++++++++++- > 2 files changed, 32 insertions(+), 1 deletion(-) > > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > index 249657c466dd..15c972f27574 100644 > --- a/kernel/bpf/btf.c > +++ b/kernel/bpf/btf.c > @@ -7819,6 +7819,7 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) > { > switch (prog_type) { > case BPF_PROG_TYPE_UNSPEC: > + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: > return BTF_KFUNC_HOOK_COMMON; > case BPF_PROG_TYPE_XDP: > return BTF_KFUNC_HOOK_XDP; > diff --git a/net/core/filter.c b/net/core/filter.c > index a094694899c9..3ed6cd33b268 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -11752,6 +11752,25 @@ __bpf_kfunc int bpf_dynptr_from_xdp(struct xdp_buff *xdp, u64 flags, > > return 0; > } > + > +__bpf_kfunc int bpf_sock_addr_set_unix_addr(struct bpf_sock_addr_kern *sa_kern, > + const u8 *addr, u32 addrlen__sz) > +{ > + struct sockaddr *sa = sa_kern->uaddr; > + struct sockaddr_un *un; > + > + if (sa_kern->sk->sk_family != AF_UNIX) > + return -EINVAL; > + > + if (addrlen__sz > UNIX_PATH_MAX) Is it valid to have addrlen__sz == 0 for AF_UNIX? > + return -EINVAL; > + > + un = (struct sockaddr_un *)sa; > + memcpy(un->sun_path, addr, addrlen__sz); > + sa_kern->uaddrlen = offsetof(struct sockaddr_un, sun_path) + addrlen__sz; > + > + return 0; > +}