Quelle  uxshm.c   Sprache: C

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
** uxshm.c -- Unix Implementations NSPR Named Shared Memory
**
**
** lth. Jul-1999.
**
*/
#include <string.h>
#include <prshm.h>
#include <prerr.h>
#include <prmem.h>
#include "primpl.h"
#include <fcntl.h>

extern PRLogModuleInfo* _pr_shm_lm;

#define NSPR_IPC_SHM_KEY 'b'
/*
** Implementation for System V
*/
#if defined PR_HAVE_SYSV_NAMED_SHARED_MEMORY
#  include <sys/ipc.h>
#  include <sys/shm.h>
#  include <sys/types.h>
#  include <sys/stat.h>

#  define _MD_OPEN_SHARED_MEMORY _MD_OpenSharedMemory
#  define _MD_ATTACH_SHARED_MEMORY _MD_AttachSharedMemory
#  define _MD_DETACH_SHARED_MEMORY _MD_DetachSharedMemory
#  define _MD_CLOSE_SHARED_MEMORY _MD_CloseSharedMemory
#  define _MD_DELETE_SHARED_MEMORY _MD_DeleteSharedMemory

extern PRSharedMemory* _MD_OpenSharedMemory(const char* name, PRSize size,
                                            PRIntn flags, PRIntn mode) {
  PRStatus rc = PR_SUCCESS;
  key_t key;
  PRSharedMemory* shm;
  char ipcname[PR_IPC_NAME_SIZE];

  rc = _PR_MakeNativeIPCName(name, ipcname, PR_IPC_NAME_SIZE, _PRIPCShm);
  if (PR_FAILURE == rc) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(
        _pr_shm_lm, PR_LOG_DEBUG,
        ("_MD_OpenSharedMemory(): _PR_MakeNativeIPCName() failed: %s", name));
    return (NULL);
  }

  shm = PR_NEWZAP(PRSharedMemory);
  if (NULL == shm) {
    PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("PR_OpenSharedMemory: New PRSharedMemory out of memory"));
    return (NULL);
  }

  shm->ipcname = (char*)PR_MALLOC(strlen(ipcname) + 1);
  if (NULL == shm->ipcname) {
    PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("PR_OpenSharedMemory: New shm->ipcname out of memory"));
    PR_DELETE(shm);
    return (NULL);
  }

  /* copy args to struct */
  strcpy(shm->ipcname, ipcname);
  shm->size = size;
  shm->mode = mode;
  shm->flags = flags;
  shm->ident = _PR_SHM_IDENT;

  /* create the file first */
  if (flags & PR_SHM_CREATE) {
    int osfd = open(shm->ipcname, (O_RDWR | O_CREAT), shm->mode);
    if (-1 == osfd) {
      _PR_MD_MAP_OPEN_ERROR(errno);
      PR_FREEIF(shm->ipcname);
      PR_DELETE(shm);
      return (NULL);
    }
    if (close(osfd) == -1) {
      _PR_MD_MAP_CLOSE_ERROR(errno);
      PR_FREEIF(shm->ipcname);
      PR_DELETE(shm);
      return (NULL);
    }
  }

  /* hash the shm.name to an ID */
  key = ftok(shm->ipcname, NSPR_IPC_SHM_KEY);
  if (-1 == key) {
    rc = PR_FAILURE;
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_OpenSharedMemory(): ftok() failed on name: %s", shm->ipcname));
    PR_FREEIF(shm->ipcname);
    PR_DELETE(shm);
    return (NULL);
  }

  /* get the shared memory */
  if (flags & PR_SHM_CREATE) {
    shm->id = shmget(key, shm->size, (shm->mode | IPC_CREAT | IPC_EXCL));
    if (shm->id >= 0) {
      return (shm);
    }
    if ((errno == EEXIST) && (flags & PR_SHM_EXCL)) {
      PR_SetError(PR_FILE_EXISTS_ERROR, errno);
      PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
             ("_MD_OpenSharedMemory(): shmget() exclusive failed, errno: %d",
              errno));
      PR_FREEIF(shm->ipcname);
      PR_DELETE(shm);
      return (NULL);
    }
  }

  shm->id = shmget(key, shm->size, shm->mode);
  if (-1 == shm->id) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_OpenSharedMemory(): shmget() failed, errno: %d", errno));
    PR_FREEIF(shm->ipcname);
    PR_DELETE(shm);
    return (NULL);
  }

  return (shm);
} /* end _MD_OpenSharedMemory() */

extern void* _MD_AttachSharedMemory(PRSharedMemory* shm, PRIntn flags) {
  void* addr;
  PRUint32 aFlags = shm->mode;

  PR_ASSERT(shm->ident == _PR_SHM_IDENT);

  aFlags |= (flags & PR_SHM_READONLY) ? SHM_RDONLY : 0;

  addr = shmat(shm->id, NULL, aFlags);
  if ((void*)-1 == addr) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_AttachSharedMemory(): shmat() failed on name: %s, OsError: %d",
            shm->ipcname, PR_GetOSError()));
    addr = NULL;
  }

  return addr;
}

extern PRStatus _MD_DetachSharedMemory(PRSharedMemory* shm, void* addr) {
  PRStatus rc = PR_SUCCESS;
  PRIntn urc;

  PR_ASSERT(shm->ident == _PR_SHM_IDENT);

  urc = shmdt(addr);
  if (-1 == urc) {
    rc = PR_FAILURE;
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(
        _pr_shm_lm, PR_LOG_DEBUG,
        ("_MD_DetachSharedMemory(): shmdt() failed on name: %s", shm->ipcname));
  }

  return rc;
}

extern PRStatus _MD_CloseSharedMemory(PRSharedMemory* shm) {
  PR_ASSERT(shm->ident == _PR_SHM_IDENT);

  PR_FREEIF(shm->ipcname);
  PR_DELETE(shm);

  return PR_SUCCESS;
}

extern PRStatus _MD_DeleteSharedMemory(const char* name) {
  PRStatus rc = PR_SUCCESS;
  key_t key;
  int id;
  PRIntn urc;
  char ipcname[PR_IPC_NAME_SIZE];

  rc = _PR_MakeNativeIPCName(name, ipcname, PR_IPC_NAME_SIZE, _PRIPCShm);
  if (PR_FAILURE == rc) {
    PR_SetError(PR_UNKNOWN_ERROR, errno);
    PR_LOG(
        _pr_shm_lm, PR_LOG_DEBUG,
        ("_MD_DeleteSharedMemory(): _PR_MakeNativeIPCName() failed: %s", name));
    return (PR_FAILURE);
  }

  /* create the file first */
  {
    int osfd = open(ipcname, (O_RDWR | O_CREAT), 0666);
    if (-1 == osfd) {
      _PR_MD_MAP_OPEN_ERROR(errno);
      return (PR_FAILURE);
    }
    if (close(osfd) == -1) {
      _PR_MD_MAP_CLOSE_ERROR(errno);
      return (PR_FAILURE);
    }
  }

  /* hash the shm.name to an ID */
  key = ftok(ipcname, NSPR_IPC_SHM_KEY);
  if (-1 == key) {
    rc = PR_FAILURE;
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DeleteSharedMemory(): ftok() failed on name: %s", ipcname));
  }

  id = shmget(key, 0, 0);
  if (-1 == id) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DeleteSharedMemory(): shmget() failed, errno: %d", errno));
    return (PR_FAILURE);
  }

  urc = shmctl(id, IPC_RMID, NULL);
  if (-1 == urc) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DeleteSharedMemory(): shmctl() failed on name: %s", ipcname));
    return (PR_FAILURE);
  }

  urc = unlink(ipcname);
  if (-1 == urc) {
    _PR_MD_MAP_UNLINK_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DeleteSharedMemory(): unlink() failed: %s", ipcname));
    return (PR_FAILURE);
  }

  return rc;
} /* end _MD_DeleteSharedMemory() */

/*
** Implementation for Posix
*/
#elif defined PR_HAVE_POSIX_NAMED_SHARED_MEMORY
#  include <sys/mman.h>

#  define _MD_OPEN_SHARED_MEMORY _MD_OpenSharedMemory
#  define _MD_ATTACH_SHARED_MEMORY _MD_AttachSharedMemory
#  define _MD_DETACH_SHARED_MEMORY _MD_DetachSharedMemory
#  define _MD_CLOSE_SHARED_MEMORY _MD_CloseSharedMemory
#  define _MD_DELETE_SHARED_MEMORY _MD_DeleteSharedMemory

struct _MDSharedMemory {
  int handle;
};

extern PRSharedMemory* _MD_OpenSharedMemory(const char* name, PRSize size,
                                            PRIntn flags, PRIntn mode) {
  PRStatus rc = PR_SUCCESS;
  PRInt32 end;
  PRSharedMemory* shm;
  char ipcname[PR_IPC_NAME_SIZE];

  rc = _PR_MakeNativeIPCName(name, ipcname, PR_IPC_NAME_SIZE, _PRIPCShm);
  if (PR_FAILURE == rc) {
    PR_SetError(PR_UNKNOWN_ERROR, errno);
    PR_LOG(
        _pr_shm_lm, PR_LOG_DEBUG,
        ("_MD_OpenSharedMemory(): _PR_MakeNativeIPCName() failed: %s", name));
    return (NULL);
  }

  shm = PR_NEWZAP(PRSharedMemory);
  if (NULL == shm) {
    PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("PR_OpenSharedMemory: New PRSharedMemory out of memory"));
    return (NULL);
  }

  shm->ipcname = PR_MALLOC(strlen(ipcname) + 1);
  if (NULL == shm->ipcname) {
    PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("PR_OpenSharedMemory: New shm->ipcname out of memory"));
    return (NULL);
  }

  /* copy args to struct */
  strcpy(shm->ipcname, ipcname);
  shm->size = size;
  shm->mode = mode;
  shm->flags = flags;
  shm->ident = _PR_SHM_IDENT;

  /*
  ** Create the shared memory
  */
  if (flags & PR_SHM_CREATE) {
    int oflag = (O_CREAT | O_RDWR);

    if (flags & PR_SHM_EXCL) {
      oflag |= O_EXCL;
    }
    shm->id = shm_open(shm->ipcname, oflag, shm->mode);
  } else {
    shm->id = shm_open(shm->ipcname, O_RDWR, shm->mode);
  }

  if (-1 == shm->id) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_OpenSharedMemory(): shm_open failed: %s, OSError: %d",
            shm->ipcname, PR_GetOSError()));
    PR_DELETE(shm->ipcname);
    PR_DELETE(shm);
    return (NULL);
  }

  end = ftruncate(shm->id, shm->size);
  if (-1 == end) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_OpenSharedMemory(): ftruncate failed, OSError: %d",
            PR_GetOSError()));
    PR_DELETE(shm->ipcname);
    PR_DELETE(shm);
    return (NULL);
  }

  return (shm);
} /* end _MD_OpenSharedMemory() */

extern void* _MD_AttachSharedMemory(PRSharedMemory* shm, PRIntn flags) {
  void* addr;
  PRIntn prot = (PROT_READ | PROT_WRITE);

  PR_ASSERT(shm->ident == _PR_SHM_IDENT);

  if (PR_SHM_READONLY == flags) {
    prot ^= PROT_WRITE;
  }

  addr = mmap((void*)0, shm->size, prot, MAP_SHARED, shm->id, 0);
  if ((void*)-1 == addr) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_AttachSharedMemory(): mmap failed: %s, errno: %d",
            shm->ipcname, PR_GetOSError()));
    addr = NULL;
  } else {
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_AttachSharedMemory(): name: %s, attached at: %p", shm->ipcname,
            addr));
  }

  return addr;
}

extern PRStatus _MD_DetachSharedMemory(PRSharedMemory* shm, void* addr) {
  PRStatus rc = PR_SUCCESS;
  PRIntn urc;

  PR_ASSERT(shm->ident == _PR_SHM_IDENT);

  urc = munmap(addr, shm->size);
  if (-1 == urc) {
    rc = PR_FAILURE;
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DetachSharedMemory(): munmap failed: %s, errno: %d",
            shm->ipcname, PR_GetOSError()));
  }
  return rc;
}

extern PRStatus _MD_CloseSharedMemory(PRSharedMemory* shm) {
  int urc;

  PR_ASSERT(shm->ident == _PR_SHM_IDENT);

  urc = close(shm->id);
  if (-1 == urc) {
    _PR_MD_MAP_CLOSE_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_CloseSharedMemory(): close() failed, error: %d",
            PR_GetOSError()));
    return (PR_FAILURE);
  }
  PR_DELETE(shm->ipcname);
  PR_DELETE(shm);
  return PR_SUCCESS;
}

extern PRStatus _MD_DeleteSharedMemory(const char* name) {
  PRStatus rc = PR_SUCCESS;
  PRUintn urc;
  char ipcname[PR_IPC_NAME_SIZE];

  rc = _PR_MakeNativeIPCName(name, ipcname, PR_IPC_NAME_SIZE, _PRIPCShm);
  if (PR_FAILURE == rc) {
    PR_SetError(PR_UNKNOWN_ERROR, errno);
    PR_LOG(
        _pr_shm_lm, PR_LOG_DEBUG,
        ("_MD_OpenSharedMemory(): _PR_MakeNativeIPCName() failed: %s", name));
    return rc;
  }

  urc = shm_unlink(ipcname);
  if (-1 == urc) {
    rc = PR_FAILURE;
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DeleteSharedMemory(): shm_unlink failed: %s, errno: %d",
            ipcname, PR_GetOSError()));
  } else {
    PR_LOG(_pr_shm_lm, PR_LOG_DEBUG,
           ("_MD_DeleteSharedMemory(): %s, success", ipcname));
  }

  return rc;
} /* end _MD_DeleteSharedMemory() */
#endif

/*
** Unix implementation for anonymous memory (file) mapping
*/
extern PRLogModuleInfo* _pr_shma_lm;

#include <unistd.h>

extern PRFileMap* _md_OpenAnonFileMap(const char* dirName, PRSize size,
                                      PRFileMapProtect prot) {
  PRFileMap* fm = NULL;
  PRFileDesc* fd;
  int osfd;
  PRIntn urc;
  PRIntn mode = 0600;
  char* genName;
  pid_t pid = getpid();                  /* for generating filename */
  PRThread* tid = PR_GetCurrentThread(); /* for generating filename */
  int incr;                              /* for generating filename */
  const int maxTries = 20; /* maximum # attempts at a unique filename */
  PRInt64 size64;          /* 64-bit version of 'size' */

  /*
  ** generate a filename from input and runtime environment
  ** open the file, unlink the file.
  ** make maxTries number of attempts at uniqueness in the filename
  */
  for (incr = 0; incr < maxTries; incr++) {
#define NSPR_AFM_FILENAME "%s/.NSPR-AFM-%d-%p.%d"
    genName = PR_smprintf(NSPR_AFM_FILENAME, dirName, (int)pid, tid, incr);
    if (NULL == genName) {
      PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
             ("_md_OpenAnonFileMap(): PR_snprintf(): failed, generating "
              "filename"));
      goto Finished;
    }

    /* create the file */
    osfd = open(genName, (O_CREAT | O_EXCL | O_RDWR), mode);
    if (-1 == osfd) {
      if (EEXIST == errno) {
        PR_smprintf_free(genName);
        continue; /* name exists, try again */
      }
      _PR_MD_MAP_OPEN_ERROR(errno);
      PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
             ("_md_OpenAnonFileMap(): open(): failed, filename: %s, errno: %d",
              genName, PR_GetOSError()));
      PR_smprintf_free(genName);
      goto Finished;
    }
    break; /* name generation and open successful, break; */
  } /* end for() */

  if (incr == maxTries) {
    PR_ASSERT(-1 == osfd);
    PR_ASSERT(EEXIST == errno);
    _PR_MD_MAP_OPEN_ERROR(errno);
    goto Finished;
  }

  urc = unlink(genName);
  if (-1 == urc) {
    _PR_MD_MAP_UNLINK_ERROR(errno);
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
           ("_md_OpenAnonFileMap(): failed on unlink(), errno: %d", errno));
    PR_smprintf_free(genName);
    close(osfd);
    goto Finished;
  }
  PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
         ("_md_OpenAnonFileMap(): unlink(): %s", genName));

  PR_smprintf_free(genName);

  fd = PR_ImportFile(osfd);
  if (NULL == fd) {
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
           ("_md_OpenAnonFileMap(): PR_ImportFile(): failed"));
    goto Finished;
  }
  PR_LOG(_pr_shma_lm, PR_LOG_DEBUG, ("_md_OpenAnonFileMap(): fd: %p", fd));

  urc = ftruncate(fd->secret->md.osfd, size);
  if (-1 == urc) {
    _PR_MD_MAP_DEFAULT_ERROR(errno);
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
           ("_md_OpenAnonFileMap(): failed on ftruncate(), errno: %d", errno));
    PR_Close(fd);
    goto Finished;
  }
  PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
         ("_md_OpenAnonFileMap(): ftruncate(): size: %d", size));

  LL_UI2L(size64, size); /* PRSize (size_t) is unsigned */
  fm = PR_CreateFileMap(fd, size64, prot);
  if (NULL == fm) {
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG, ("PR_OpenAnonFileMap(): failed"));
    PR_Close(fd);
    goto Finished;
  }
  fm->md.isAnonFM = PR_TRUE; /* set fd close */

  PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
         ("_md_OpenAnonFileMap(): PR_CreateFileMap(): fm: %p", fm));

Finished:
  return (fm);
} /* end md_OpenAnonFileMap() */

/*
** _md_ExportFileMapAsString()
**
**
*/
extern PRStatus _md_ExportFileMapAsString(PRFileMap* fm, PRSize bufSize,
                                          char* buf) {
  PRIntn written;
  PRIntn prot = (PRIntn)fm->prot;

  written = PR_snprintf(buf, bufSize, "%ld:%d", fm->fd->secret->md.osfd, prot);

  return ((written == -1) ? PR_FAILURE : PR_SUCCESS);
} /* end _md_ExportFileMapAsString() */

extern PRFileMap* _md_ImportFileMapFromString(const char* fmstring) {
  PRStatus rc;
  PRInt32 osfd;
  PRIntn prot; /* really: a PRFileMapProtect */
  PRFileDesc* fd;
  PRFileMap* fm = NULL; /* default return value */
  PRFileInfo64 info;

  PR_sscanf(fmstring, "%ld:%d", &osfd, &prot);

  /* import the os file descriptor */
  fd = PR_ImportFile(osfd);
  if (NULL == fd) {
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
           ("_md_ImportFileMapFromString(): PR_ImportFile() failed"));
    goto Finished;
  }

  rc = PR_GetOpenFileInfo64(fd, &info);
  if (PR_FAILURE == rc) {
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
           ("_md_ImportFileMapFromString(): PR_GetOpenFileInfo64() failed"));
    goto Finished;
  }

  fm = PR_CreateFileMap(fd, info.size, (PRFileMapProtect)prot);
  if (NULL == fm) {
    PR_LOG(_pr_shma_lm, PR_LOG_DEBUG,
           ("_md_ImportFileMapFromString(): PR_CreateFileMap() failed"));
  }

Finished:
  return (fm);
} /* end _md_ImportFileMapFromString() */