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([2804:431:c7cb:55a:c067:29b:4c08:be99]) by smtp.gmail.com with ESMTPSA id e2sm5711482ooh.40.2021.11.08.10.30.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Nov 2021 10:30:35 -0800 (PST) Message-ID: Date: Mon, 8 Nov 2021 15:30:33 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [PATCH v2 2/2] linux: Fix ancillary 64-bit time timestamp conversion (BZ #28349, BZ #28350) Content-Language: en-US From: Adhemerval Zanella To: libc-alpha@sourceware.org, Florian Weimer References: <20210929140619.279302-1-adhemerval.zanella@linaro.org> <20210929140619.279302-2-adhemerval.zanella@linaro.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-13.7 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: Mon, 08 Nov 2021 18:30:43 -0000 Ping (x3). On 20/10/2021 09:08, Adhemerval Zanella wrote: > Ping (x2). > > On 08/10/2021 08:58, Adhemerval Zanella wrote: >> Ping. >> >> On 29/09/2021 11:06, 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. >>> >>> --- >>> v2: Fix some typos and use support_socket_time64_timestamp. >>> >>> --- >>> sysdeps/unix/sysv/linux/Makefile | 3 + >>> .../unix/sysv/linux/convert_scm_timestamps.c | 40 +-- >>> .../sysv/linux/tst-socket-timestamp-time64.c | 1 + >>> .../unix/sysv/linux/tst-socket-timestamp.c | 338 ++++++++++++++++++ >>> 4 files changed, 362 insertions(+), 20 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 76ad06361c..3399c87468 100644 >>> --- a/sysdeps/unix/sysv/linux/Makefile >>> +++ b/sysdeps/unix/sysv/linux/Makefile >>> @@ -262,6 +262,9 @@ 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..5ee930035b 100644 >>> --- a/sysdeps/unix/sysv/linux/convert_scm_timestamps.c >>> +++ b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c >>> @@ -54,26 +54,26 @@ __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) >>> cmsg != NULL; >>> cmsg = CMSG_NXTHDR (msg, cmsg)) >>> { >>> - if (cmsg->cmsg_level != SOL_SOCKET) >>> - continue; >>> - >>> - switch (cmsg->cmsg_type) >>> + if (cmsg->cmsg_level == SOL_SOCKET) >>> { >>> - case COMPAT_SO_TIMESTAMP_OLD: >>> - if (type != 0) >>> - break; >>> - type = COMPAT_SO_TIMESTAMP_NEW; >>> - goto common; >>> - >>> - case COMPAT_SO_TIMESTAMPNS_OLD: >>> - type = COMPAT_SO_TIMESTAMPNS_NEW; >>> - >>> - /* fallthrough */ >>> - common: >>> - memcpy (tmp, CMSG_DATA (cmsg), sizeof (tmp)); >>> - tvts[0] = tmp[0]; >>> - tvts[1] = tmp[1]; >>> - break; >>> + switch (cmsg->cmsg_type) >>> + { >>> + case COMPAT_SO_TIMESTAMP_OLD: >>> + if (type != 0) >>> + break; >>> + type = COMPAT_SO_TIMESTAMP_NEW; >>> + goto common; >>> + >>> + case COMPAT_SO_TIMESTAMPNS_OLD: >>> + type = COMPAT_SO_TIMESTAMPNS_NEW; >>> + >>> + /* fallthrough */ >>> + common: >>> + memcpy (tmp, CMSG_DATA (cmsg), sizeof (tmp)); >>> + tvts[0] = tmp[0]; >>> + tvts[1] = tmp[1]; >>> + break; >>> + } >>> } >>> >>> last = cmsg; >>> @@ -89,7 +89,7 @@ __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) >>> } >>> >>> msg->msg_controllen += CMSG_SPACE (sizeof tvts); >>> - cmsg = CMSG_NXTHDR(msg, last); >>> + cmsg = CMSG_NXTHDR (msg, last); >>> if (cmsg == NULL) >>> return; >>> cmsg->cmsg_level = SOL_SOCKET; >>> 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..9aaa705054 >>> --- /dev/null >>> +++ b/sysdeps/unix/sysv/linux/tst-socket-timestamp.c >>> @@ -0,0 +1,338 @@ >>> +/* 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 msgs = CMSG_SPACE (tsize) + slack; >>> + struct mmsghdr mmhdr = >>> + { >>> + .msg_hdr = >>> + { >>> + .msg_name = NULL, >>> + .msg_namelen = 0, >>> + .msg_iov = &iov, >>> + .msg_iovlen = 1, >>> + .msg_controllen = msgs, >>> + .msg_control = cmsg != NULL ? cmsg - msgs : NULL, >>> + }, >>> + }; >>> + >>> + 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++) >>> + 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++) >>> + 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 >>>