/* $Id: pipe-posix.cpp $ */ /** @file * IPRT - Anonymous Pipes, POSIX Implementation. */ /* * Copyright (C) 2010-2019 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * The contents of this file may alternatively be used under the terms * of the Common Development and Distribution License Version 1.0 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the * VirtualBox OSE distribution, in which case the provisions of the * CDDL are applicable instead of those of the GPL. * * You may elect to license modified versions of this file under the * terms and conditions of either the GPL or the CDDL or both. */ /********************************************************************************************************************************* * Header Files * *********************************************************************************************************************************/ #include #include "internal/iprt.h" #include #include #include #include #include #include #include #include "internal/magics.h" #include #include #include #include #include #include #include #include #ifdef RT_OS_LINUX # include #endif #ifdef RT_OS_SOLARIS # include #endif #include "internal/pipe.h" /********************************************************************************************************************************* * Structures and Typedefs * *********************************************************************************************************************************/ typedef struct RTPIPEINTERNAL { /** Magic value (RTPIPE_MAGIC). */ uint32_t u32Magic; /** The file descriptor. */ int fd; /** Set if this is the read end, clear if it's the write end. */ bool fRead; /** Atomically operated state variable. * * - Bits 0 thru 29 - Users of the new mode. * - Bit 30 - The pipe mode, set indicates blocking. * - Bit 31 - Set when we're switching the mode. */ uint32_t volatile u32State; } RTPIPEINTERNAL; /********************************************************************************************************************************* * Defined Constants And Macros * *********************************************************************************************************************************/ /** @name RTPIPEINTERNAL::u32State defines * @{ */ #define RTPIPE_POSIX_BLOCKING UINT32_C(0x40000000) #define RTPIPE_POSIX_SWITCHING UINT32_C(0x80000000) #define RTPIPE_POSIX_SWITCHING_BIT 31 #define RTPIPE_POSIX_USERS_MASK UINT32_C(0x3fffffff) /** @} */ /** * Wrapper for calling pipe2() or pipe(). * * When using pipe2() the returned handles are marked close-on-exec and does * not risk racing process creation calls on other threads. * * @returns See pipe(). * @param paFds See pipe(). * @param piNewPipeSyscall Where to cache which call we should used. -1 if * pipe(), 1 if pipe2(), 0 if not yet decided. */ static int my_pipe_wrapper(int *paFds, int *piNewPipeSyscall) { if (*piNewPipeSyscall >= 0) { #if defined(RT_OS_LINUX) && defined(__NR_pipe2) && defined(O_CLOEXEC) long rc = syscall(__NR_pipe2, paFds, O_CLOEXEC); if (rc >= 0) { if (*piNewPipeSyscall == 0) *piNewPipeSyscall = 1; return (int)rc; } #endif *piNewPipeSyscall = -1; } return pipe(paFds); } RTDECL(int) RTPipeCreate(PRTPIPE phPipeRead, PRTPIPE phPipeWrite, uint32_t fFlags) { AssertPtrReturn(phPipeRead, VERR_INVALID_POINTER); AssertPtrReturn(phPipeWrite, VERR_INVALID_POINTER); AssertReturn(!(fFlags & ~RTPIPE_C_VALID_MASK), VERR_INVALID_PARAMETER); /* * Create the pipe and clear/set the close-on-exec flag as required. */ int aFds[2] = {-1, -1}; static int s_iNewPipeSyscall = 0; if (my_pipe_wrapper(aFds, &s_iNewPipeSyscall)) return RTErrConvertFromErrno(errno); int rc = VINF_SUCCESS; if (s_iNewPipeSyscall > 0) { /* created with close-on-exec set. */ if (fFlags & RTPIPE_C_INHERIT_READ) { if (fcntl(aFds[0], F_SETFD, 0)) rc = RTErrConvertFromErrno(errno); } if (fFlags & RTPIPE_C_INHERIT_WRITE) { if (fcntl(aFds[1], F_SETFD, 0)) rc = RTErrConvertFromErrno(errno); } } else { /* created with close-on-exec cleared. */ if (!(fFlags & RTPIPE_C_INHERIT_READ)) { if (fcntl(aFds[0], F_SETFD, FD_CLOEXEC)) rc = RTErrConvertFromErrno(errno); } if (!(fFlags & RTPIPE_C_INHERIT_WRITE)) { if (fcntl(aFds[1], F_SETFD, FD_CLOEXEC)) rc = RTErrConvertFromErrno(errno); } } if (RT_SUCCESS(rc)) { /* * Create the two handles. */ RTPIPEINTERNAL *pThisR = (RTPIPEINTERNAL *)RTMemAlloc(sizeof(RTPIPEINTERNAL)); if (pThisR) { RTPIPEINTERNAL *pThisW = (RTPIPEINTERNAL *)RTMemAlloc(sizeof(RTPIPEINTERNAL)); if (pThisW) { pThisR->u32Magic = RTPIPE_MAGIC; pThisW->u32Magic = RTPIPE_MAGIC; pThisR->fd = aFds[0]; pThisW->fd = aFds[1]; pThisR->fRead = true; pThisW->fRead = false; pThisR->u32State = RTPIPE_POSIX_BLOCKING; pThisW->u32State = RTPIPE_POSIX_BLOCKING; *phPipeRead = pThisR; *phPipeWrite = pThisW; /* * Before we leave, make sure to shut up SIGPIPE. */ signal(SIGPIPE, SIG_IGN); return VINF_SUCCESS; } RTMemFree(pThisR); rc = VERR_NO_MEMORY; } else rc = VERR_NO_MEMORY; } close(aFds[0]); close(aFds[1]); return rc; } RTDECL(int) RTPipeClose(RTPIPE hPipe) { RTPIPEINTERNAL *pThis = hPipe; if (pThis == NIL_RTPIPE) return VINF_SUCCESS; AssertPtrReturn(pThis, VERR_INVALID_PARAMETER); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); /* * Do the cleanup. */ AssertReturn(ASMAtomicCmpXchgU32(&pThis->u32Magic, ~RTPIPE_MAGIC, RTPIPE_MAGIC), VERR_INVALID_HANDLE); int fd = pThis->fd; pThis->fd = -1; close(fd); if (ASMAtomicReadU32(&pThis->u32State) & RTPIPE_POSIX_USERS_MASK) { AssertFailed(); RTThreadSleep(1); } RTMemFree(pThis); return VINF_SUCCESS; } RTDECL(int) RTPipeFromNative(PRTPIPE phPipe, RTHCINTPTR hNativePipe, uint32_t fFlags) { AssertPtrReturn(phPipe, VERR_INVALID_POINTER); AssertReturn(!(fFlags & ~RTPIPE_N_VALID_MASK), VERR_INVALID_PARAMETER); AssertReturn(!!(fFlags & RTPIPE_N_READ) != !!(fFlags & RTPIPE_N_WRITE), VERR_INVALID_PARAMETER); /* * Get and validate the pipe handle info. */ int hNative = (int)hNativePipe; struct stat st; AssertReturn(fstat(hNative, &st) == 0, RTErrConvertFromErrno(errno)); AssertMsgReturn(S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode), ("%#x (%o)\n", st.st_mode, st.st_mode), VERR_INVALID_HANDLE); int fFd = fcntl(hNative, F_GETFL, 0); AssertReturn(fFd != -1, VERR_INVALID_HANDLE); AssertMsgReturn( (fFd & O_ACCMODE) == (fFlags & RTPIPE_N_READ ? O_RDONLY : O_WRONLY) || (fFd & O_ACCMODE) == O_RDWR /* Solaris creates bi-directional pipes. */ , ("%#x\n", fFd), VERR_INVALID_HANDLE); /* * Create the handle. */ RTPIPEINTERNAL *pThis = (RTPIPEINTERNAL *)RTMemAlloc(sizeof(RTPIPEINTERNAL)); if (!pThis) return VERR_NO_MEMORY; pThis->u32Magic = RTPIPE_MAGIC; pThis->fd = hNative; pThis->fRead = !!(fFlags & RTPIPE_N_READ); pThis->u32State = fFd & O_NONBLOCK ? 0 : RTPIPE_POSIX_BLOCKING; /* * Fix up inheritability and shut up SIGPIPE and we're done. */ if (fcntl(hNative, F_SETFD, fFlags & RTPIPE_N_INHERIT ? 0 : FD_CLOEXEC) == 0) { signal(SIGPIPE, SIG_IGN); *phPipe = pThis; return VINF_SUCCESS; } int rc = RTErrConvertFromErrno(errno); RTMemFree(pThis); return rc; } RTDECL(RTHCINTPTR) RTPipeToNative(RTPIPE hPipe) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, -1); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, -1); return pThis->fd; } /** * Prepare blocking mode. * * @returns VINF_SUCCESS * @retval VERR_WRONG_ORDER * @retval VERR_INTERNAL_ERROR_4 * * @param pThis The pipe handle. */ static int rtPipeTryBlocking(RTPIPEINTERNAL *pThis) { /* * Update the state. */ for (;;) { uint32_t u32State = ASMAtomicReadU32(&pThis->u32State); uint32_t const u32StateOld = u32State; uint32_t const cUsers = (u32State & RTPIPE_POSIX_USERS_MASK); if (u32State & RTPIPE_POSIX_BLOCKING) { AssertReturn(cUsers < RTPIPE_POSIX_USERS_MASK / 2, VERR_INTERNAL_ERROR_4); u32State &= ~RTPIPE_POSIX_USERS_MASK; u32State |= cUsers + 1; if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld)) { if (u32State & RTPIPE_POSIX_SWITCHING) break; return VINF_SUCCESS; } } else if (cUsers == 0) { u32State = 1 | RTPIPE_POSIX_SWITCHING | RTPIPE_POSIX_BLOCKING; if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld)) break; } else return VERR_WRONG_ORDER; ASMNopPause(); } /* * Do the switching. */ int fFlags = fcntl(pThis->fd, F_GETFL, 0); if (fFlags != -1) { if ( !(fFlags & O_NONBLOCK) || fcntl(pThis->fd, F_SETFL, fFlags & ~O_NONBLOCK) != -1) { ASMAtomicBitClear(&pThis->u32State, RTPIPE_POSIX_SWITCHING_BIT); return VINF_SUCCESS; } } ASMAtomicDecU32(&pThis->u32State); return RTErrConvertFromErrno(errno); } /** * Prepare non-blocking mode. * * @returns VINF_SUCCESS * @retval VERR_WRONG_ORDER * @retval VERR_INTERNAL_ERROR_4 * * @param pThis The pipe handle. */ static int rtPipeTryNonBlocking(RTPIPEINTERNAL *pThis) { /* * Update the state. */ for (;;) { uint32_t u32State = ASMAtomicReadU32(&pThis->u32State); uint32_t const u32StateOld = u32State; uint32_t const cUsers = (u32State & RTPIPE_POSIX_USERS_MASK); if (!(u32State & RTPIPE_POSIX_BLOCKING)) { AssertReturn(cUsers < RTPIPE_POSIX_USERS_MASK / 2, VERR_INTERNAL_ERROR_4); u32State &= ~RTPIPE_POSIX_USERS_MASK; u32State |= cUsers + 1; if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld)) { if (u32State & RTPIPE_POSIX_SWITCHING) break; return VINF_SUCCESS; } } else if (cUsers == 0) { u32State = 1 | RTPIPE_POSIX_SWITCHING; if (ASMAtomicCmpXchgU32(&pThis->u32State, u32State, u32StateOld)) break; } else return VERR_WRONG_ORDER; ASMNopPause(); } /* * Do the switching. */ int fFlags = fcntl(pThis->fd, F_GETFL, 0); if (fFlags != -1) { if ( (fFlags & O_NONBLOCK) || fcntl(pThis->fd, F_SETFL, fFlags | O_NONBLOCK) != -1) { ASMAtomicBitClear(&pThis->u32State, RTPIPE_POSIX_SWITCHING_BIT); return VINF_SUCCESS; } } ASMAtomicDecU32(&pThis->u32State); return RTErrConvertFromErrno(errno); } /** * Checks if the read pipe has a HUP condition. * * @returns true if HUP, false if no. * @param pThis The pipe handle (read). */ static bool rtPipePosixHasHup(RTPIPEINTERNAL *pThis) { Assert(pThis->fRead); struct pollfd PollFd; RT_ZERO(PollFd); PollFd.fd = pThis->fd; PollFd.events = POLLHUP; return poll(&PollFd, 1, 0) >= 1 && (PollFd.revents & POLLHUP); } RTDECL(int) RTPipeRead(RTPIPE hPipe, void *pvBuf, size_t cbToRead, size_t *pcbRead) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(pThis->fRead, VERR_ACCESS_DENIED); AssertPtr(pcbRead); AssertPtr(pvBuf); int rc = rtPipeTryNonBlocking(pThis); if (RT_SUCCESS(rc)) { ssize_t cbRead = read(pThis->fd, pvBuf, RT_MIN(cbToRead, SSIZE_MAX)); if (cbRead >= 0) { if (cbRead || !cbToRead || !rtPipePosixHasHup(pThis)) *pcbRead = cbRead; else rc = VERR_BROKEN_PIPE; } else if (errno == EAGAIN) { *pcbRead = 0; rc = VINF_TRY_AGAIN; } else rc = RTErrConvertFromErrno(errno); ASMAtomicDecU32(&pThis->u32State); } return rc; } RTDECL(int) RTPipeReadBlocking(RTPIPE hPipe, void *pvBuf, size_t cbToRead, size_t *pcbRead) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(pThis->fRead, VERR_ACCESS_DENIED); AssertPtr(pvBuf); int rc = rtPipeTryBlocking(pThis); if (RT_SUCCESS(rc)) { size_t cbTotalRead = 0; while (cbToRead > 0) { ssize_t cbRead = read(pThis->fd, pvBuf, RT_MIN(cbToRead, SSIZE_MAX)); if (cbRead < 0) { rc = RTErrConvertFromErrno(errno); break; } if (!cbRead && rtPipePosixHasHup(pThis)) { rc = VERR_BROKEN_PIPE; break; } /* advance */ pvBuf = (char *)pvBuf + cbRead; cbTotalRead += cbRead; cbToRead -= cbRead; } if (pcbRead) { *pcbRead = cbTotalRead; if ( RT_FAILURE(rc) && cbTotalRead && rc != VERR_INVALID_POINTER) rc = VINF_SUCCESS; } ASMAtomicDecU32(&pThis->u32State); } return rc; } RTDECL(int) RTPipeWrite(RTPIPE hPipe, const void *pvBuf, size_t cbToWrite, size_t *pcbWritten) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(!pThis->fRead, VERR_ACCESS_DENIED); AssertPtr(pcbWritten); AssertPtr(pvBuf); int rc = rtPipeTryNonBlocking(pThis); if (RT_SUCCESS(rc)) { if (cbToWrite) { ssize_t cbWritten = write(pThis->fd, pvBuf, RT_MIN(cbToWrite, SSIZE_MAX)); if (cbWritten >= 0) *pcbWritten = cbWritten; else if (errno == EAGAIN) { *pcbWritten = 0; rc = VINF_TRY_AGAIN; } else rc = RTErrConvertFromErrno(errno); } else *pcbWritten = 0; ASMAtomicDecU32(&pThis->u32State); } return rc; } RTDECL(int) RTPipeWriteBlocking(RTPIPE hPipe, const void *pvBuf, size_t cbToWrite, size_t *pcbWritten) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(!pThis->fRead, VERR_ACCESS_DENIED); AssertPtr(pvBuf); AssertPtrNull(pcbWritten); int rc = rtPipeTryBlocking(pThis); if (RT_SUCCESS(rc)) { size_t cbTotalWritten = 0; while (cbToWrite > 0) { ssize_t cbWritten = write(pThis->fd, pvBuf, RT_MIN(cbToWrite, SSIZE_MAX)); if (cbWritten < 0) { rc = RTErrConvertFromErrno(errno); break; } /* advance */ pvBuf = (char const *)pvBuf + cbWritten; cbTotalWritten += cbWritten; cbToWrite -= cbWritten; } if (pcbWritten) { *pcbWritten = cbTotalWritten; if ( RT_FAILURE(rc) && cbTotalWritten && rc != VERR_INVALID_POINTER) rc = VINF_SUCCESS; } ASMAtomicDecU32(&pThis->u32State); } return rc; } RTDECL(int) RTPipeFlush(RTPIPE hPipe) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(!pThis->fRead, VERR_ACCESS_DENIED); if (fsync(pThis->fd)) { if (errno == EINVAL || errno == ENOTSUP) return VERR_NOT_SUPPORTED; return RTErrConvertFromErrno(errno); } return VINF_SUCCESS; } RTDECL(int) RTPipeSelectOne(RTPIPE hPipe, RTMSINTERVAL cMillies) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); struct pollfd PollFd; RT_ZERO(PollFd); PollFd.fd = pThis->fd; PollFd.events = POLLHUP | POLLERR; if (pThis->fRead) PollFd.events |= POLLIN | POLLPRI; else PollFd.events |= POLLOUT; int timeout; if ( cMillies == RT_INDEFINITE_WAIT || cMillies >= INT_MAX /* lazy bird */) timeout = -1; else timeout = cMillies; int rc = poll(&PollFd, 1, timeout); if (rc == -1) return RTErrConvertFromErrno(errno); return rc > 0 ? VINF_SUCCESS : VERR_TIMEOUT; } RTDECL(int) RTPipeQueryReadable(RTPIPE hPipe, size_t *pcbReadable) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(pThis->fRead, VERR_PIPE_NOT_READ); AssertPtrReturn(pcbReadable, VERR_INVALID_POINTER); int cb = 0; int rc = ioctl(pThis->fd, FIONREAD, &cb); if (rc != -1) { AssertStmt(cb >= 0, cb = 0); *pcbReadable = cb; return VINF_SUCCESS; } rc = errno; if (rc == ENOTTY) rc = VERR_NOT_SUPPORTED; else rc = RTErrConvertFromErrno(rc); return rc; } RTDECL(int) RTPipeQueryInfo(RTPIPE hPipe, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, 0); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, 0); rtPipeFakeQueryInfo(pObjInfo, enmAddAttr, pThis->fRead); if (pThis->fRead) { int cb = 0; int rc = ioctl(pThis->fd, FIONREAD, &cb); if (rc >= 0) pObjInfo->cbObject = cb; } #ifdef FIONSPACE else { int cb = 0; int rc = ioctl(pThis->fd, FIONSPACE, &cb); if (rc >= 0) pObjInfo->cbObject = cb; } #endif /** @todo Check this out on linux, solaris and darwin... (Currently going by a * FreeBSD manpage.) */ struct stat St; if (fstat(pThis->fd, &St)) { pObjInfo->cbAllocated = St.st_blksize; if ( enmAddAttr == RTFSOBJATTRADD_NOTHING || enmAddAttr == RTFSOBJATTRADD_UNIX) { pObjInfo->Attr.enmAdditional = RTFSOBJATTRADD_UNIX; pObjInfo->Attr.u.Unix.INodeId = St.st_ino; pObjInfo->Attr.u.Unix.INodeIdDevice = St.st_dev; } } /** @todo error handling? */ return VINF_SUCCESS; } int rtPipePollGetHandle(RTPIPE hPipe, uint32_t fEvents, PRTHCINTPTR phNative) { RTPIPEINTERNAL *pThis = hPipe; AssertPtrReturn(pThis, VERR_INVALID_HANDLE); AssertReturn(pThis->u32Magic == RTPIPE_MAGIC, VERR_INVALID_HANDLE); AssertReturn(!(fEvents & RTPOLL_EVT_READ) || pThis->fRead, VERR_INVALID_PARAMETER); AssertReturn(!(fEvents & RTPOLL_EVT_WRITE) || !pThis->fRead, VERR_INVALID_PARAMETER); *phNative = pThis->fd; return VINF_SUCCESS; }