From 13c51549e2077f2f3bf84e8fd0b46d8b0c615912 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Mon, 7 Sep 2020 17:08:46 -0300 Subject: linux: Add fallback for 64-bit time_t SO_TIMESTAMP{NS} The recvmsg handling is more complicated because it requires check the returned kernel control message and make some convertions. For !__ASSUME_TIME64_SYSCALLS it converts the first 32-bit time SO_TIMESTAMP or SO_TIMESTAMPNS and appends it to the control buffer if has extra space or returns MSG_CTRUNC otherwise. The 32-bit time field is kept as-is. Calls with __TIMESIZE=32 will see the converted 64-bit time control messages as spurious control message of unknown type. Calls with __TIMESIZE=64 running on pre-time64 kernels will see the original message as a spurious control ones of unknown typ while running on kernel with native 64-bit time support will only see the time64 version of the control message. Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15 kernel). Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- include/sys/socket.h | 5 ++ sysdeps/unix/sysv/linux/Makefile | 2 +- sysdeps/unix/sysv/linux/convert_scm_timestamps.c | 95 ++++++++++++++++++++++ sysdeps/unix/sysv/linux/getsockopt.c | 12 +++ .../unix/sysv/linux/hppa/socket-constants-time64.h | 5 ++ .../unix/sysv/linux/mips/socket-constants-time64.h | 5 ++ .../sysv/linux/powerpc/socket-constants-time64.h | 5 ++ sysdeps/unix/sysv/linux/recvmsg.c | 23 ++++-- sysdeps/unix/sysv/linux/setsockopt.c | 12 +++ sysdeps/unix/sysv/linux/socket-constants-time64.h | 5 ++ .../sysv/linux/sparc/socket-constants-time64.h | 5 ++ 11 files changed, 167 insertions(+), 7 deletions(-) create mode 100644 sysdeps/unix/sysv/linux/convert_scm_timestamps.c diff --git a/include/sys/socket.h b/include/sys/socket.h index 0e39dd2a3a..38a1f76b3b 100644 --- a/include/sys/socket.h +++ b/include/sys/socket.h @@ -164,5 +164,10 @@ libc_hidden_proto (__libc_sa_len) libc_hidden_proto (__cmsg_nxthdr) +#ifndef __ASSUME_TIME64_SYSCALLS +extern void __convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) + attribute_hidden; +#endif + #endif #endif diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile index bc14f20274..36d5ae020c 100644 --- a/sysdeps/unix/sysv/linux/Makefile +++ b/sysdeps/unix/sysv/linux/Makefile @@ -64,7 +64,7 @@ sysdep_routines += adjtimex clone umount umount2 readahead sysctl \ time64-support pselect32 \ xstat fxstat lxstat xstat64 fxstat64 lxstat64 \ fxstatat fxstatat64 \ - xmknod xmknodat + xmknod xmknodat convert_scm_timestamps CFLAGS-gethostid.c = -fexceptions CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables diff --git a/sysdeps/unix/sysv/linux/convert_scm_timestamps.c b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c new file mode 100644 index 0000000000..d75a4618dd --- /dev/null +++ b/sysdeps/unix/sysv/linux/convert_scm_timestamps.c @@ -0,0 +1,95 @@ +/* Socket timestamp conversion routines. + 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 + +#ifndef __ASSUME_TIME64_SYSCALLS +# include +# include +# include +# include + +/* It converts the first SO_TIMESTAMP or SO_TIMESTAMPNS with 32-bit time and + appends it to the control buffer. The 32-bit time field is kept as-is. + + Calls with __TIMESIZE=32 will see the converted 64-bit time control + messages as spurious control message of unknown type. + + Calls with __TIMESIZE=64 running on pre-time64 kernels will see the + original message as a spurious control ones of unknown typ while running + on kernel with native 64-bit time support will only see the time64 version + of the control message. */ +void +__convert_scm_timestamps (struct msghdr *msg, socklen_t msgsize) +{ + if (msg->msg_control == NULL || msg->msg_controllen == 0) + return; + + /* The returned control message format for SO_TIMESTAMP_NEW is a + 'struct __kernel_sock_timeval' while for SO_TIMESTAMPNS_NEW is a + 'struct __kernel_timespec'. In either case it is two uint64_t + members. */ + uint64_t tvts[2]; + + struct cmsghdr *cmsg, *last = NULL; + int type = 0; + + for (cmsg = CMSG_FIRSTHDR (msg); + cmsg != NULL; + cmsg = CMSG_NXTHDR (msg, cmsg)) + { + if (cmsg->cmsg_level != SOL_SOCKET) + continue; + + 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 (tvts, CMSG_DATA (cmsg), sizeof (tvts)); + break; + } + + last = cmsg; + } + + if (last == NULL || type == 0) + return; + + if (CMSG_SPACE (sizeof tvts) > msgsize - msg->msg_controllen) + { + msg->msg_flags |= MSG_CTRUNC; + return; + } + + msg->msg_controllen += CMSG_SPACE (sizeof tvts); + cmsg = CMSG_NXTHDR(msg, last); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = type; + cmsg->cmsg_len = CMSG_LEN (sizeof tvts); + memcpy (CMSG_DATA (cmsg), tvts, sizeof tvts); +} +#endif diff --git a/sysdeps/unix/sysv/linux/getsockopt.c b/sysdeps/unix/sysv/linux/getsockopt.c index 688a7de087..f86b06dec6 100644 --- a/sysdeps/unix/sysv/linux/getsockopt.c +++ b/sysdeps/unix/sysv/linux/getsockopt.c @@ -70,6 +70,18 @@ getsockopt32 (int fd, int level, int optname, void *optval, else memcpy (optval, &tv32, sizeof tv32); } + break; + + case COMPAT_SO_TIMESTAMP_NEW: + case COMPAT_SO_TIMESTAMPNS_NEW: + { + if (optname == COMPAT_SO_TIMESTAMP_NEW) + optname = COMPAT_SO_TIMESTAMP_OLD; + if (optname == COMPAT_SO_TIMESTAMPNS_NEW) + optname = COMPAT_SO_TIMESTAMPNS_OLD; + r = getsockopt_syscall (fd, level, optname, optval, len); + } + break; } return r; diff --git a/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h b/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h index 9fe7576aaa..0a48990ad8 100644 --- a/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h +++ b/sysdeps/unix/sysv/linux/hppa/socket-constants-time64.h @@ -27,4 +27,9 @@ #define COMPAT_SO_RCVTIMEO_NEW 16448 #define COMPAT_SO_SNDTIMEO_NEW 16449 +#define COMPAT_SO_TIMESTAMP_OLD 0x4012 +#define COMPAT_SO_TIMESTAMPNS_OLD 0x4013 +#define COMPAT_SO_TIMESTAMP_NEW 0x4038 +#define COMPAT_SO_TIMESTAMPNS_NEW 0x4039 + #endif diff --git a/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h b/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h index 1252a8a23b..728f7aa456 100644 --- a/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h +++ b/sysdeps/unix/sysv/linux/mips/socket-constants-time64.h @@ -27,4 +27,9 @@ #define COMPAT_SO_RCVTIMEO_NEW 66 #define COMPAT_SO_SNDTIMEO_NEW 67 +#define COMPAT_SO_TIMESTAMP_OLD 29 +#define COMPAT_SO_TIMESTAMPNS_OLD 35 +#define COMPAT_SO_TIMESTAMP_NEW 63 +#define COMPAT_SO_TIMESTAMPNS_NEW 64 + #endif diff --git a/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h b/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h index 26e8b710ab..c231b7285a 100644 --- a/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h +++ b/sysdeps/unix/sysv/linux/powerpc/socket-constants-time64.h @@ -27,4 +27,9 @@ #define COMPAT_SO_RCVTIMEO_NEW 66 #define COMPAT_SO_SNDTIMEO_NEW 67 +#define COMPAT_SO_TIMESTAMP_OLD 29 +#define COMPAT_SO_TIMESTAMPNS_OLD 35 +#define COMPAT_SO_TIMESTAMP_NEW 63 +#define COMPAT_SO_TIMESTAMPNS_NEW 64 + #endif diff --git a/sysdeps/unix/sysv/linux/recvmsg.c b/sysdeps/unix/sysv/linux/recvmsg.c index b209b4ad99..a2a600228b 100644 --- a/sysdeps/unix/sysv/linux/recvmsg.c +++ b/sysdeps/unix/sysv/linux/recvmsg.c @@ -19,16 +19,27 @@ #include #include #include -#include ssize_t __libc_recvmsg (int fd, struct msghdr *msg, int flags) { -# ifdef __ASSUME_RECVMSG_SYSCALL - return SYSCALL_CANCEL (recvmsg, fd, msg, flags); -# else - return SOCKETCALL_CANCEL (recvmsg, fd, msg, flags); -# endif + ssize_t r; +#ifndef __ASSUME_TIME64_SYSCALLS + socklen_t orig_controllen = msg->msg_controllen; +#endif + +#ifdef __ASSUME_RECVMSG_SYSCALL + r = SYSCALL_CANCEL (recvmsg, fd, msg, flags); +#else + r = SOCKETCALL_CANCEL (recvmsg, fd, msg, flags); +#endif + +#ifndef __ASSUME_TIME64_SYSCALLS + if (r >= 0) + __convert_scm_timestamps (msg, orig_controllen); +#endif + + return r; } weak_alias (__libc_recvmsg, recvmsg) weak_alias (__libc_recvmsg, __recvmsg) diff --git a/sysdeps/unix/sysv/linux/setsockopt.c b/sysdeps/unix/sysv/linux/setsockopt.c index 6505202265..a4780a9d33 100644 --- a/sysdeps/unix/sysv/linux/setsockopt.c +++ b/sysdeps/unix/sysv/linux/setsockopt.c @@ -69,6 +69,18 @@ setsockopt32 (int fd, int level, int optname, const void *optval, r = setsockopt_syscall (fd, level, optname, &tv32, sizeof (tv32)); } + break; + + case COMPAT_SO_TIMESTAMP_NEW: + case COMPAT_SO_TIMESTAMPNS_NEW: + { + if (optname == COMPAT_SO_TIMESTAMP_NEW) + optname = COMPAT_SO_TIMESTAMP_OLD; + if (optname == COMPAT_SO_TIMESTAMPNS_NEW) + optname = COMPAT_SO_TIMESTAMPNS_OLD; + r = setsockopt_syscall (fd, level, optname, NULL, 0); + } + break; } return r; diff --git a/sysdeps/unix/sysv/linux/socket-constants-time64.h b/sysdeps/unix/sysv/linux/socket-constants-time64.h index d09c39d6c2..6cb249cc32 100644 --- a/sysdeps/unix/sysv/linux/socket-constants-time64.h +++ b/sysdeps/unix/sysv/linux/socket-constants-time64.h @@ -27,4 +27,9 @@ #define COMPAT_SO_RCVTIMEO_NEW 66 #define COMPAT_SO_SNDTIMEO_NEW 67 +#define COMPAT_SO_TIMESTAMP_OLD 29 +#define COMPAT_SO_TIMESTAMPNS_OLD 35 +#define COMPAT_SO_TIMESTAMP_NEW 63 +#define COMPAT_SO_TIMESTAMPNS_NEW 64 + #endif diff --git a/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h b/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h index f4668db537..4242cb6d19 100644 --- a/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h +++ b/sysdeps/unix/sysv/linux/sparc/socket-constants-time64.h @@ -27,4 +27,9 @@ #define COMPAT_SO_RCVTIMEO_NEW 68 #define COMPAT_SO_SNDTIMEO_NEW 69 +#define COMPAT_SO_TIMESTAMP_OLD 0x001d +#define COMPAT_SO_TIMESTAMPNS_OLD 0x0021 +#define COMPAT_SO_TIMESTAMP_NEW 0x0046 +#define COMPAT_SO_TIMESTAMPNS_NEW 0x0042 + #endif -- cgit v1.2.3