text: /*
   * QEMU low level functions
   *
   * Copyright (c) 2003 Fabrice Bellard
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  #include "qemu/osdep.h"
  #include "qapi/error.h"
  
  /* Needed early for CONFIG_BSD etc. */
  
  #ifdef CONFIG_SOLARIS
  #include <sys/statvfs.h>
  /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
     discussion about Solaris header problems */
  extern int madvise(char *, size_t, int);
  #endif
  
  #include "qemu-common.h"
  #include "qemu/cutils.h"
  #include "qemu/sockets.h"
  #include "qemu/error-report.h"
  #include "monitor/monitor.h"
  
  static bool fips_enabled = false;
  
  static const char *hw_version = QEMU_HW_VERSION;
  
  int socket_set_cork(int fd, int v)
  {
  #if defined(SOL_TCP) && defined(TCP_CORK)
      return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
  #else
      return 0;
  #endif
  }
  
  int socket_set_nodelay(int fd)
  {
      int v = 1;
      return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
  }
  
  int qemu_madvise(void *addr, size_t len, int advice)
  {
      if (advice == QEMU_MADV_INVALID) {
          errno = EINVAL;
          return -1;
      }
  #if defined(CONFIG_MADVISE)
      return madvise(addr, len, advice);
  #elif defined(CONFIG_POSIX_MADVISE)
      return posix_madvise(addr, len, advice);
  #else
      errno = EINVAL;
      return -1;
  #endif
  }
  
  static int qemu_mprotect__osdep(void *addr, size_t size, int prot)
  {
      g_assert(!((uintptr_t)addr & ~qemu_real_host_page_mask));
      g_assert(!(size & ~qemu_real_host_page_mask));
  
  #ifdef _WIN32
      DWORD old_protect;
  
      if (!VirtualProtect(addr, size, prot, &old_protect)) {
          g_autofree gchar *emsg = g_win32_error_message(GetLastError());
          error_report("%s: VirtualProtect failed: %s", __func__, emsg);
          return -1;
      }
      return 0;
  #else
      if (mprotect(addr, size, prot)) {
          error_report("%s: mprotect failed: %s", __func__, strerror(errno));
          return -1;
      }
      return 0;
  #endif
  }
  
  int qemu_mprotect_rwx(void *addr, size_t size)
  {
  #ifdef _WIN32
      return qemu_mprotect__osdep(addr, size, PAGE_EXECUTE_READWRITE);
  #else
      return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
  #endif
  }
  
  int qemu_mprotect_none(void *addr, size_t size)
  {
  #ifdef _WIN32
      return qemu_mprotect__osdep(addr, size, PAGE_NOACCESS);
  #else
      return qemu_mprotect__osdep(addr, size, PROT_NONE);
  #endif
  }
  
  #ifndef _WIN32
  
  static int fcntl_op_setlk = -1;
  static int fcntl_op_getlk = -1;
  
  /*
   * Dups an fd and sets the flags
   */
  int qemu_dup_flags(int fd, int flags)
  {
      int ret;
      int serrno;
      int dup_flags;
  
      ret = qemu_dup(fd);
      if (ret == -1) {
          goto fail;
      }
  
      dup_flags = fcntl(ret, F_GETFL);
      if (dup_flags == -1) {
          goto fail;
      }
  
      if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
          errno = EINVAL;
          goto fail;
      }
  
      /* Set/unset flags that we can with fcntl */
      if (fcntl(ret, F_SETFL, flags) == -1) {
          goto fail;
      }
  
      /* Truncate the file in the cases that open() would truncate it */
      if (flags & O_TRUNC ||
              ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
          if (ftruncate(ret, 0) == -1) {
              goto fail;
          }
      }
  
      return ret;
  
  fail:
      serrno = errno;
      if (ret != -1) {
          close(ret);
      }
      errno = serrno;
      return -1;
  }
  
  int qemu_dup(int fd)
  {
      int ret;
  #ifdef F_DUPFD_CLOEXEC
      ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
  #else
      ret = dup(fd);
      if (ret != -1) {
          qemu_set_cloexec(ret);
      }
  #endif
      return ret;
  }
  
  static int qemu_parse_fdset(const char *param)
  {
      return qemu_parse_fd(param);
  }
  
  static void qemu_probe_lock_ops(void)
  {
      if (fcntl_op_setlk == -1) {
  #ifdef F_OFD_SETLK
          int fd;
          int ret;
          struct flock fl = {
              .l_whence = SEEK_SET,
              .l_start  = 0,
              .l_len    = 0,
              .l_type   = F_WRLCK,
          };
  
          fd = open("/dev/null", O_RDWR);
          if (fd < 0) {
              fprintf(stderr,
                      "Failed to open /dev/null for OFD lock probing: %s\n",
                      strerror(errno));
              fcntl_op_setlk = F_SETLK;
              fcntl_op_getlk = F_GETLK;
              return;
          }
          ret = fcntl(fd, F_OFD_GETLK, &fl);
          close(fd);
          if (!ret) {
              fcntl_op_setlk = F_OFD_SETLK;
              fcntl_op_getlk = F_OFD_GETLK;
          } else {
              fcntl_op_setlk = F_SETLK;
              fcntl_op_getlk = F_GETLK;
          }
  #else
          fcntl_op_setlk = F_SETLK;
          fcntl_op_getlk = F_GETLK;
  #endif
      }
  }
  
  bool qemu_has_ofd_lock(void)
  {
      qemu_probe_lock_ops();
  #ifdef F_OFD_SETLK
      return fcntl_op_setlk == F_OFD_SETLK;
  #else
      return false;
  #endif
  }
  
  static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type)
  {
      int ret;
      struct flock fl = {
          .l_whence = SEEK_SET,
          .l_start  = start,
          .l_len    = len,
          .l_type   = fl_type,
      };
      qemu_probe_lock_ops();
      do {
          ret = fcntl(fd, fcntl_op_setlk, &fl);
      } while (ret == -1 && errno == EINTR);
      return ret == -1 ? -errno : 0;
  }
  
  int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive)
  {
      return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK);
  }
  
  int qemu_unlock_fd(int fd, int64_t start, int64_t len)
  {
      return qemu_lock_fcntl(fd, start, len, F_UNLCK);
  }
  
  int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive)
  {
      int ret;
      struct flock fl = {
          .l_whence = SEEK_SET,
          .l_start  = start,
          .l_len    = len,
          .l_type   = exclusive ? F_WRLCK : F_RDLCK,
      };
      qemu_probe_lock_ops();
      ret = fcntl(fd, fcntl_op_getlk, &fl);
      if (ret == -1) {
          return -errno;
      } else {
          return fl.l_type == F_UNLCK ? 0 : -EAGAIN;
      }
  }
  #endif
  
  static int qemu_open_cloexec(const char *name, int flags, mode_t mode)
  {
      int ret;
  #ifdef O_CLOEXEC
      ret = open(name, flags | O_CLOEXEC, mode);
  #else
      ret = open(name, flags, mode);
      if (ret >= 0) {
          qemu_set_cloexec(ret);
      }
  #endif
      return ret;
  }
  
  /*
   * Opens a file with FD_CLOEXEC set
   */
  static int
  qemu_open_internal(const char *name, int flags, mode_t mode, Error **errp)
  {
      int ret;
  
  #ifndef _WIN32
      const char *fdset_id_str;
  
      /* Attempt dup of fd from fd set */
      if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
          int64_t fdset_id;
          int dupfd;
  
          fdset_id = qemu_parse_fdset(fdset_id_str);
          if (fdset_id == -1) {
              error_setg(errp, "Could not parse fdset %s", name);
              errno = EINVAL;
              return -1;
          }
  
          dupfd = monitor_fdset_dup_fd_add(fdset_id, flags);
          if (dupfd == -1) {
              error_setg_errno(errp, errno, "Could not dup FD for %s flags %x",
                               name, flags);
              return -1;
          }
  
          return dupfd;
      }
  #endif
  
      ret = qemu_open_cloexec(name, flags, mode);
  
      if (ret == -1) {
          const char *action = flags & O_CREAT ? "create" : "open";
  #ifdef O_DIRECT
          /* Give more helpful error message for O_DIRECT */
          if (errno == EINVAL && (flags & O_DIRECT)) {
              ret = open(name, flags & ~O_DIRECT, mode);
              if (ret != -1) {
                  close(ret);
                  error_setg(errp, "Could not %s '%s': "
                             "filesystem does not support O_DIRECT",
                             action, name);
                  errno = EINVAL; /* restore first open()'s errno */
                  return -1;
              }
          }
  #endif /* O_DIRECT */
          error_setg_errno(errp, errno, "Could not %s '%s'",
                           action, name);
      }
  
      return ret;
  }
  
  
  int qemu_open(const char *name, int flags, Error **errp)
  {
      assert(!(flags & O_CREAT));
  
      return qemu_open_internal(name, flags, 0, errp);
  }
  
  
  int qemu_create(const char *name, int flags, mode_t mode, Error **errp)
  {
      assert(!(flags & O_CREAT));
  
      return qemu_open_internal(name, flags | O_CREAT, mode, errp);
  }
  
  
  int qemu_open_old(const char *name, int flags, ...)
  {
      va_list ap;
      mode_t mode = 0;
      int ret;
  
      va_start(ap, flags);
      if (flags & O_CREAT) {
          mode = va_arg(ap, int);
      }
      va_end(ap);
  
      ret = qemu_open_internal(name, flags, mode, NULL);
  
  #ifdef O_DIRECT
      if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
          error_report("file system may not support O_DIRECT");
          errno = EINVAL; /* in case it was clobbered */
      }
  #endif /* O_DIRECT */
  
      return ret;
  }
  
  int qemu_close(int fd)
  {
      int64_t fdset_id;
  
      /* Close fd that was dup'd from an fdset */
      fdset_id = monitor_fdset_dup_fd_find(fd);
      if (fdset_id != -1) {
          int ret;
  
          ret = close(fd);
          if (ret == 0) {
              monitor_fdset_dup_fd_remove(fd);
          }
  
          return ret;
      }
  
      return close(fd);
  }
  
  /*
   * Delete a file from the filesystem, unless the filename is /dev/fdset/...
   *
   * Returns: On success, zero is returned.  On error, -1 is returned,
   * and errno is set appropriately.
   */
  int qemu_unlink(const char *name)
  {
      if (g_str_has_prefix(name, "/dev/fdset/")) {
          return 0;
      }
  
      return unlink(name);
  }
  
  /*
   * A variant of write(2) which handles partial write.
   *
   * Return the number of bytes transferred.
   * Set errno if fewer than `count' bytes are written.
   *
   * This function don't work with non-blocking fd's.
   * Any of the possibilities with non-blocking fd's is bad:
   *   - return a short write (then name is wrong)
   *   - busy wait adding (errno == EAGAIN) to the loop
   */
  ssize_t qemu_write_full(int fd, const void *buf, size_t count)
  {
      ssize_t ret = 0;
      ssize_t total = 0;
  
      while (count) {
          ret = write(fd, buf, count);
          if (ret < 0) {
              if (errno == EINTR)
                  continue;
              break;
          }
  
          count -= ret;
          buf += ret;
          total += ret;
      }
  
      return total;
  }
  
  /*
   * Opens a socket with FD_CLOEXEC set
   */
  int qemu_socket(int domain, int type, int protocol)
  {
      int ret;
  
  #ifdef SOCK_CLOEXEC
      ret = socket(domain, type | SOCK_CLOEXEC, protocol);
      if (ret != -1 || errno != EINVAL) {
          return ret;
      }
  #endif
      ret = socket(domain, type, protocol);
      if (ret >= 0) {
          qemu_set_cloexec(ret);
      }
  
      return ret;
  }
  
  /*
   * Accept a connection and set FD_CLOEXEC
   */
  int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
  {
      int ret;
  
  #ifdef CONFIG_ACCEPT4
      ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
      if (ret != -1 || errno != ENOSYS) {
          return ret;
      }
  #endif
      ret = accept(s, addr, addrlen);
      if (ret >= 0) {
          qemu_set_cloexec(ret);
      }
  
      return ret;
  }
  
  void qemu_set_hw_version(const char *version)
  {
      hw_version = version;
  }
  
  const char *qemu_hw_version(void)
  {
      return hw_version;
  }
  
  void fips_set_state(bool requested)
  {
  #ifdef __linux__
      if (requested) {
          FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
          if (fds != NULL) {
              fips_enabled = (fgetc(fds) == '1');
              fclose(fds);
          }
      }
  #else
      fips_enabled = false;
  #endif /* __linux__ */
  
  #ifdef _FIPS_DEBUG
      fprintf(stderr, "FIPS mode %s (requested %s)\n",
              (fips_enabled ? "enabled" : "disabled"),
              (requested ? "enabled" : "disabled"));
  #endif
  }
  
  bool fips_get_state(void)
  {
      return fips_enabled;
  }
  
  #ifdef _WIN32
  static void socket_cleanup(void)
  {
      WSACleanup();
  }
  #endif
  
  int socket_init(void)
  {
  #ifdef _WIN32
      WSADATA Data;
      int ret, err;
  
      ret = WSAStartup(MAKEWORD(2, 2), &Data);
      if (ret != 0) {
          err = WSAGetLastError();
          fprintf(stderr, "WSAStartup: %d\n", err);
          return -1;
      }
      atexit(socket_cleanup);
  #endif
      return 0;
  }
  
  
  #ifndef CONFIG_IOVEC
  /* helper function for iov_send_recv() */
  static ssize_t
  readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
  {
      unsigned i = 0;
      ssize_t ret = 0;
      while (i < iov_cnt) {
          ssize_t r = do_write
              ? write(fd, iov[i].iov_base, iov[i].iov_len)
              : read(fd, iov[i].iov_base, iov[i].iov_len);
          if (r > 0) {
              ret += r;
          } else if (!r) {
              break;
          } else if (errno == EINTR) {
              continue;
          } else {
              /* else it is some "other" error,
               * only return if there was no data processed. */
              if (ret == 0) {
                  ret = -1;
              }
              break;
          }
          i++;
      }
      return ret;
  }
  
  ssize_t
  readv(int fd, const struct iovec *iov, int iov_cnt)
  {
      return readv_writev(fd, iov, iov_cnt, false);
  }
  
  ssize_t
  writev(int fd, const struct iovec *iov, int iov_cnt)
  {
      return readv_writev(fd, iov, iov_cnt, true);
  }
  #endif
  