From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua1-x92d.google.com (mail-ua1-x92d.google.com [IPv6:2607:f8b0:4864:20::92d]) by sourceware.org (Postfix) with ESMTPS id 0DC78393D035 for ; Wed, 12 Jan 2022 13:36:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0DC78393D035 Received: by mail-ua1-x92d.google.com with SMTP id u6so4901738uaq.0 for ; Wed, 12 Jan 2022 05:36:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:references:in-reply-to :content-transfer-encoding; bh=/llA1iDpAWyCHtkmR/kaOjwTf1UcD45QnrGGuPcO5Bs=; b=QBNSwuhiV84PtNQ+gk5qoTZUNAMyqPj/22KjViN8x4spfitU3l1Qfucg18DJqI3VSk m6yuCHE6tjcG5HHtIpoSSpDf9KGN/wLDDqPjACeMoLPfKTk4DdazNFXfENb8Jm7l7j4/ oKwiih7TAaSEe7+MSVBE3Jb/fIvb0JOoRuUbaetEDvmCG+AXbPLsiRRG1ps80F08jzZn EqLnSNt1GKjTh42Ei39Q9S1diOMl26xBmw+nVxBacIPbX4NM3kBRYYHbXTi39EgoiOr3 KaogXJhLN+gcyIgK0fwzLWG2BOA/RgqsBSV4qNE3ggX9wfRyrxRZ59mktYxX210TgqB1 2nrA== X-Gm-Message-State: AOAM531epTukPtT5xPRa8ARMcUP7cVkQnCDkjvKhE99rdfTmvck6jWUG 8tvCvdM9UBCKwKK0vc3x8LDa18kjbQtkZA== X-Google-Smtp-Source: ABdhPJzg7WXCg60g27mecS+3W72defA/lSxEjZqqt65QsfdmiawMLKoaHsIftEghH8NBwp+cXZBMrQ== X-Received: by 2002:ab0:30e6:: with SMTP id d6mr4086447uam.85.1641994566261; Wed, 12 Jan 2022 05:36:06 -0800 (PST) Received: from ?IPV6:2804:431:c7ca:9d3:c0ae:6d7d:7ec1:f457? ([2804:431:c7ca:9d3:c0ae:6d7d:7ec1:f457]) by smtp.gmail.com with ESMTPSA id m62sm7757143uam.0.2022.01.12.05.36.05 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Jan 2022 05:36:05 -0800 (PST) Message-ID: <64dacd16-f356-523b-41fe-e7cc992ee375@linaro.org> Date: Wed, 12 Jan 2022 10:36:04 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v4] linux: Fix ancillary 64-bit time timestamp conversion (BZ #28349, BZ #28350) Content-Language: en-US From: Adhemerval Zanella To: libc-alpha@sourceware.org References: <20211222185239.1088511-1-adhemerval.zanella@linaro.org> In-Reply-To: <20211222185239.1088511-1-adhemerval.zanella@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Jan 2022 13:36:09 -0000 I wrongly pushed this upstream and I will revert it. Sorry about the noise. On 22/12/2021 15:52, Adhemerval Zanella wrote: > The __convert_scm_timestamps() only updates the control message last > pointer for SOL_SOCKET type, so if the message control buffer contains > multiple ancillary message types the converted timestamp one might > overwrite a valid message. > > The test check if the extra ancillary space is correctly handled > by recvmsg/recvmmsg, where if there is no extra space for the 64-bit > time_t converted message the control buffer should be marked with > MSG_TRUNC. It also check if recvmsg/recvmmsg handle correctly multiple > ancillary data. > > Checked on x86_64-linux and on i686-linux-gnu on both 5.11 and > 4.15 kernel. > > Co-authored-by: Fabian Vogt > --- > v3: Fix unitilized data usage by CMSG_NXTHDR [1] > > [1] https://patchwork.sourceware.org/project/glibc/patch/7960950.1uK8C5oMiK@linux-e202.suse.de/ > --- > sysdeps/unix/sysv/linux/Makefile | 3 + > .../unix/sysv/linux/convert_scm_timestamps.c | 11 +- > .../sysv/linux/tst-socket-timestamp-time64.c | 1 + > .../unix/sysv/linux/tst-socket-timestamp.c | 344 ++++++++++++++++++ > 4 files changed, 354 insertions(+), 5 deletions(-) > create mode 100644 sysdeps/unix/sysv/linux/tst-socket-timestamp-time64.c > create mode 100644 sysdeps/unix/sysv/linux/tst-socket-timestamp.c > > diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile > index 61acc1987d..60aa9d89d6 100644 > --- a/sysdeps/unix/sysv/linux/Makefile > +++ b/sysdeps/unix/sysv/linux/Makefile > @@ -275,6 +275,9 @@ sysdep_routines += cmsg_nxthdr > CFLAGS-recvmmsg.c = -fexceptions -fasynchronous-unwind-tables > CFLAGS-sendmmsg.c = -fexceptions -fasynchronous-unwind-tables > > +tests += tst-socket-timestamp > +tests-time64 += tst-socket-timestamp-time64 > + > tests-special += $(objpfx)tst-socket-consts.out > $(objpfx)tst-socket-consts.out: ../sysdeps/unix/sysv/linux/tst-socket-consts.py > PYTHONPATH=../scripts \ > diff --git a/sysdeps/unix/sysv/linux/convert_scm_timestamps.c b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c > index 00c934c413..36976c276f 100644 > --- a/sysdeps/unix/sysv/linux/convert_scm_timestamps.c > +++ b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c > @@ -54,6 +54,8 @@ __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) > cmsg != NULL; > cmsg = CMSG_NXTHDR (msg, cmsg)) > { > + last = cmsg; > + > if (cmsg->cmsg_level != SOL_SOCKET) > continue; > > @@ -75,8 +77,6 @@ __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) > tvts[1] = tmp[1]; > break; > } > - > - last = cmsg; > } > > if (last == NULL || type == 0) > @@ -88,10 +88,11 @@ __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) > return; > } > > + /* Zero memory for the new cmsghdr, required by CMSG_NXTHDR. */ > + memset (msg->msg_control + msg->msg_controllen, 0, > + CMSG_SPACE (sizeof tvts)); > msg->msg_controllen += CMSG_SPACE (sizeof tvts); > - cmsg = CMSG_NXTHDR(msg, last); > - if (cmsg == NULL) > - return; > + cmsg = CMSG_NXTHDR (msg, last); > cmsg->cmsg_level = SOL_SOCKET; > cmsg->cmsg_type = type; > cmsg->cmsg_len = CMSG_LEN (sizeof tvts); > diff --git a/sysdeps/unix/sysv/linux/tst-socket-timestamp-time64.c b/sysdeps/unix/sysv/linux/tst-socket-timestamp-time64.c > new file mode 100644 > index 0000000000..ae424c2a70 > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/tst-socket-timestamp-time64.c > @@ -0,0 +1 @@ > +#include "tst-socket-timestamp.c" > diff --git a/sysdeps/unix/sysv/linux/tst-socket-timestamp.c b/sysdeps/unix/sysv/linux/tst-socket-timestamp.c > new file mode 100644 > index 0000000000..3854c46bad > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/tst-socket-timestamp.c > @@ -0,0 +1,344 @@ > +/* Check recvmsg/recvmmsg 64-bit timestamp support. > + Copyright (C) 2021 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + . */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* Some extra space added for ancillary data, it might be used to convert > + 32-bit timestamp to 64-bit for _TIME_BITS=64. */ > +enum { slack_max_size = 64 }; > +static const int slack[] = { 0, 4, 8, 16, 32, slack_max_size }; > + > +static bool support_64_timestamp; > +/* AF_INET socket and address used to send and receive data. */ > +static int srv; > +static struct sockaddr_in srv_addr; > + > +static int > +do_sendto (const struct sockaddr_in *addr, int nmsgs) > +{ > + int s = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0); > + xconnect (s, (const struct sockaddr *) addr, sizeof (*addr)); > + > + for (int i = 0; i < nmsgs; i++) > + xsendto (s, &i, sizeof (i), 0, (const struct sockaddr *) addr, > + sizeof (*addr)); > + > + return 0; > +} > + > +static void > +do_recvmsg_slack_ancillary (bool use_multi_call, int s, void *cmsg, > + size_t slack, size_t tsize, int exp_msg) > +{ > + int msg; > + struct iovec iov = > + { > + .iov_base = &msg, > + .iov_len = sizeof (msg) > + }; > + size_t msg_controllen = CMSG_SPACE (tsize) + slack; > + char *msg_control = cmsg - msg_controllen; > + memset (msg_control, 0x55, msg_controllen); > + struct mmsghdr mmhdr = > + { > + .msg_hdr = > + { > + .msg_name = NULL, > + .msg_namelen = 0, > + .msg_iov = &iov, > + .msg_iovlen = 1, > + .msg_control = msg_control, > + .msg_controllen = msg_controllen > + }, > + }; > + > + int r; > + if (use_multi_call) > + { > + r = recvmmsg (s, &mmhdr, 1, 0, NULL); > + if (r >= 0) > + r = mmhdr.msg_len; > + } > + else > + r = recvmsg (s, &mmhdr.msg_hdr, 0); > + TEST_COMPARE (r, sizeof (int)); > + TEST_COMPARE (msg, exp_msg); > + > + if (cmsg == NULL) > + return; > + > + /* A timestamp is expected if 32-bit timestamp are used (support in every > + configuration) or if underlying kernel support 64-bit timestamps. > + Otherwise recvmsg will need extra space do add the 64-bit timestamp. */ > + bool exp_timestamp; > + if (sizeof (time_t) == 4 || support_64_timestamp) > + exp_timestamp = true; > + else > + exp_timestamp = slack >= CMSG_SPACE (tsize); > + > + bool timestamp = false; > + for (struct cmsghdr *cmsg = CMSG_FIRSTHDR (&mmhdr.msg_hdr); > + cmsg != NULL; > + cmsg = CMSG_NXTHDR (&mmhdr.msg_hdr, cmsg)) > + { > + if (cmsg->cmsg_level != SOL_SOCKET) > + continue; > + if (cmsg->cmsg_type == SCM_TIMESTAMP > + && cmsg->cmsg_len == CMSG_LEN (sizeof (struct timeval))) > + { > + struct timeval tv; > + memcpy (&tv, CMSG_DATA (cmsg), sizeof (tv)); > + if (test_verbose) > + printf ("SCM_TIMESTAMP: {%jd, %jd}\n", (intmax_t)tv.tv_sec, > + (intmax_t)tv.tv_usec); > + timestamp = true; > + } > + else if (cmsg->cmsg_type == SCM_TIMESTAMPNS > + && cmsg->cmsg_len == CMSG_LEN (sizeof (struct timespec))) > + { > + struct timespec ts; > + memcpy (&ts, CMSG_DATA (cmsg), sizeof (ts)); > + if (test_verbose) > + printf ("SCM_TIMESTAMPNS: {%jd, %jd}\n", (intmax_t)ts.tv_sec, > + (intmax_t)ts.tv_nsec); > + timestamp = true; > + } > + } > + > + /* If there is not timestamp in the ancilliary data, recvmsg should set > + the flag inidcating it. */ > + if (exp_timestamp && !timestamp) > + TEST_VERIFY (mmhdr.msg_hdr.msg_flags & MSG_TRUNC); > + else > + TEST_COMPARE (timestamp, exp_timestamp); > +} > + > +/* Check if the extra ancillary space is correctly handled by recvmsg and > + recvmmsg: if there is no extra space for the 64-bit timestamp the syscall > + should set MSG_TRUNC flag, otherwise an extra cmsghdr with the converted > + timestamp is appended at the message control buffer. */ > +static void > +do_test_slack_space (void) > +{ > + /* Setup the ancillary data buffer with an extra page with PROT_NONE to > + check the possible timestamp conversion on some systems. */ > + struct support_next_to_fault nf = > + support_next_to_fault_allocate (slack_max_size); > + void *msgbuf = nf.buffer + slack_max_size; > + > + /* Enable the timestamp using struct timeval precision. */ > + { > + int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMP, &(int){1}, > + sizeof (int)); > + TEST_VERIFY_EXIT (r != -1); > + } > + /* Check recvmsg. */ > + do_sendto (&srv_addr, array_length (slack)); > + for (int s = 0; s < array_length (slack); s++) { > + memset (nf.buffer, 0x55, nf.length); > + do_recvmsg_slack_ancillary (false, srv, msgbuf, slack[s], > + sizeof (struct timeval), s); > + } > + /* Check recvmmsg. */ > + do_sendto (&srv_addr, array_length (slack)); > + for (int s = 0; s < array_length (slack); s++) { > + memset (nf.buffer, 0x55, nf.length); > + do_recvmsg_slack_ancillary (true, srv, msgbuf, slack[s], > + sizeof (struct timeval), s); > + } > + > + /* Now enable timestamp using a higher precision, it overwrites the previous > + precision. */ > + { > + int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMPNS, &(int){1}, > + sizeof (int)); > + TEST_VERIFY_EXIT (r != -1); > + } > + /* Check recvmsg. */ > + do_sendto (&srv_addr, array_length (slack)); > + for (int s = 0; s < array_length (slack); s++) > + do_recvmsg_slack_ancillary (false, srv, msgbuf, slack[s], > + sizeof (struct timespec), s); > + /* Check recvmmsg. */ > + do_sendto (&srv_addr, array_length (slack)); > + for (int s = 0; s < array_length (slack); s++) > + do_recvmsg_slack_ancillary (true, srv, msgbuf, slack[s], > + sizeof (struct timespec), s); > + > + support_next_to_fault_free (&nf); > +} > + > +/* Check if the converted 64-bit timestamp is correctly appended when there > + are multiple ancillary messages. */ > +static void > +do_recvmsg_multiple_ancillary (bool use_multi_call, int s, void *cmsg, > + size_t cmsgsize, int exp_msg) > +{ > + int msg; > + struct iovec iov = > + { > + .iov_base = &msg, > + .iov_len = sizeof (msg) > + }; > + size_t msgs = cmsgsize; > + struct mmsghdr mmhdr = > + { > + .msg_hdr = > + { > + .msg_name = NULL, > + .msg_namelen = 0, > + .msg_iov = &iov, > + .msg_iovlen = 1, > + .msg_controllen = msgs, > + .msg_control = cmsg, > + }, > + }; > + > + int r; > + if (use_multi_call) > + { > + r = recvmmsg (s, &mmhdr, 1, 0, NULL); > + if (r >= 0) > + r = mmhdr.msg_len; > + } > + else > + r = recvmsg (s, &mmhdr.msg_hdr, 0); > + TEST_COMPARE (r, sizeof (int)); > + TEST_COMPARE (msg, exp_msg); > + > + if (cmsg == NULL) > + return; > + > + bool timestamp = false; > + bool origdstaddr = false; > + for (struct cmsghdr *cmsg = CMSG_FIRSTHDR (&mmhdr.msg_hdr); > + cmsg != NULL; > + cmsg = CMSG_NXTHDR (&mmhdr.msg_hdr, cmsg)) > + { > + if (cmsg->cmsg_level == SOL_IP > + && cmsg->cmsg_type == IP_ORIGDSTADDR > + && cmsg->cmsg_len >= CMSG_LEN (sizeof (struct sockaddr_in))) > + { > + struct sockaddr_in sa; > + memcpy (&sa, CMSG_DATA (cmsg), sizeof (sa)); > + if (test_verbose) > + { > + char str[INET_ADDRSTRLEN]; > + inet_ntop (AF_INET, &sa.sin_addr, str, INET_ADDRSTRLEN); > + printf ("IP_ORIGDSTADDR: %s:%d\n", str, ntohs (sa.sin_port)); > + } > + origdstaddr = sa.sin_addr.s_addr == srv_addr.sin_addr.s_addr > + && sa.sin_port == srv_addr.sin_port; > + } > + if (cmsg->cmsg_level == SOL_SOCKET > + && cmsg->cmsg_type == SCM_TIMESTAMP > + && cmsg->cmsg_len >= CMSG_LEN (sizeof (struct timeval))) > + { > + struct timeval tv; > + memcpy (&tv, CMSG_DATA (cmsg), sizeof (tv)); > + if (test_verbose) > + printf ("SCM_TIMESTAMP: {%jd, %jd}\n", (intmax_t)tv.tv_sec, > + (intmax_t)tv.tv_usec); > + timestamp = true; > + } > + } > + > + /* If there is no timestamp in the ancillary data, recvmsg should set > + the flag to indicate it. */ > + if (!timestamp) > + TEST_VERIFY (mmhdr.msg_hdr.msg_flags & MSG_TRUNC); > + else > + TEST_COMPARE (timestamp, true); > + TEST_COMPARE (origdstaddr, true); > +} > + > +static void > +do_test_multiple_ancillary (void) > +{ > + { > + int r = setsockopt (srv, SOL_SOCKET, SO_TIMESTAMP, &(int){1}, > + sizeof (int)); > + TEST_VERIFY_EXIT (r != -1); > + } > + { > + int r = setsockopt (srv, IPPROTO_IP, IP_RECVORIGDSTADDR, &(int){1}, > + sizeof (int)); > + TEST_VERIFY_EXIT (r != -1); > + } > + > + /* Enougth data for default SO_TIMESTAMP, the IP_RECVORIGDSTADDR, and the > + extra 64-bit SO_TIMESTAMP. */ > + enum { msgbuflen = CMSG_SPACE (2 * sizeof (uint64_t)) > + + CMSG_SPACE (sizeof (struct sockaddr_in)) > + + CMSG_SPACE (2 * sizeof (uint64_t)) }; > + char msgbuf[msgbuflen]; > + > + enum { nmsgs = 8 }; > + /* Check recvmsg. */ > + do_sendto (&srv_addr, nmsgs); > + for (int s = 0; s < nmsgs; s++) > + do_recvmsg_multiple_ancillary (false, srv, msgbuf, msgbuflen, s); > + /* Check recvmmsg. */ > + do_sendto (&srv_addr, nmsgs); > + for (int s = 0; s < nmsgs; s++) > + do_recvmsg_multiple_ancillary (true, srv, msgbuf, msgbuflen, s); > +} > + > +static int > +do_test (void) > +{ > + srv = xsocket (AF_INET, SOCK_DGRAM, 0); > + srv_addr = (struct sockaddr_in) { > + .sin_family = AF_INET, > + .sin_addr = {.s_addr = htonl (INADDR_LOOPBACK) }, > + }; > + xbind (srv, (struct sockaddr *) &srv_addr, sizeof (srv_addr)); > + { > + socklen_t sa_len = sizeof (srv_addr); > + xgetsockname (srv, (struct sockaddr *) &srv_addr, &sa_len); > + TEST_VERIFY (sa_len == sizeof (srv_addr)); > + } > + > + TEST_COMPARE (recvmsg (-1, NULL, 0), -1); > + TEST_COMPARE (errno, EBADF); > + TEST_COMPARE (recvmmsg (-1, NULL, 0, 0, NULL), -1); > + TEST_COMPARE (errno, EBADF); > + > + /* If underlying kernel does not support */ > + support_64_timestamp = support_socket_so_timestamp_time64 (srv); > + > + do_test_slack_space (); > + do_test_multiple_ancillary (); > + > + xclose (srv); > + > + return 0; > +} > + > +#include