/src/libgit2/src/util/futils.c

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/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */

#include "futils.h"

#include "runtime.h"
#include "hash.h"
#include "rand.h"
#include "hashmap_str.h"

#include <ctype.h>

#define GIT_FILEMODE_DEFAULT 0100666

int git_futils_mkpath2file(const char *file_path, const mode_t mode)
{
  return git_futils_mkdir(
    file_path, mode,
    GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
}

int git_futils_mktmp(git_str *path_out, const char *filename, mode_t mode)
{
  const int open_flags = O_RDWR | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC;
  unsigned int tries = 32;
  int fd;

  while (tries--) {
    uint64_t rand = git_rand_next();

    git_str_sets(path_out, filename);
    git_str_puts(path_out, "_git2_");
    git_str_encode_hexstr(path_out, (void *)&rand, sizeof(uint64_t));

    if (git_str_oom(path_out))
      return -1;

    /* Note that we open with O_CREAT | O_EXCL */
    if ((fd = p_open(path_out->ptr, open_flags, mode)) >= 0)
      return fd;
  }

  git_error_set(GIT_ERROR_OS,
    "failed to create temporary file '%s'", path_out->ptr);
  git_str_dispose(path_out);
  return -1;
}

int git_futils_creat_withpath(const char *path, const mode_t dirmode, const mode_t mode)
{
  int fd;

  if (git_futils_mkpath2file(path, dirmode) < 0)
    return -1;

  fd = p_creat(path, mode);
  if (fd < 0) {
    git_error_set(GIT_ERROR_OS, "failed to create file '%s'", path);
    return -1;
  }

  return fd;
}

int git_futils_creat_locked(const char *path, const mode_t mode)
{
  int fd = p_open(path, O_WRONLY | O_CREAT | O_EXCL | O_BINARY | O_CLOEXEC,
    mode);

  if (fd < 0) {
    int error = errno;
    git_error_set(GIT_ERROR_OS, "failed to create locked file '%s'", path);
    switch (error) {
    case EEXIST:
      return GIT_ELOCKED;
    case ENOENT:
      return GIT_ENOTFOUND;
    default:
      return -1;
    }
  }

  return fd;
}

int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode)
{
  if (git_futils_mkpath2file(path, dirmode) < 0)
    return -1;

  return git_futils_creat_locked(path, mode);
}

int git_futils_open_ro(const char *path)
{
  int fd = p_open(path, O_RDONLY);
  if (fd < 0)
    return git_fs_path_set_error(errno, path, "open");
  return fd;
}

int git_futils_truncate(const char *path, int mode)
{
  int fd = p_open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
  if (fd < 0)
    return git_fs_path_set_error(errno, path, "open");

  close(fd);
  return 0;
}

int git_futils_filesize(uint64_t *out, git_file fd)
{
  struct stat sb;

  if (p_fstat(fd, &sb)) {
    git_error_set(GIT_ERROR_OS, "failed to stat file descriptor");
    return -1;
  }

  if (sb.st_size < 0) {
    git_error_set(GIT_ERROR_INVALID, "invalid file size");
    return -1;
  }

  *out = sb.st_size;
  return 0;
}

mode_t git_futils_canonical_mode(mode_t raw_mode)
{
  if (S_ISREG(raw_mode))
    return S_IFREG | GIT_PERMS_CANONICAL(raw_mode);
  else if (S_ISLNK(raw_mode))
    return S_IFLNK;
  else if (S_ISGITLINK(raw_mode))
    return S_IFGITLINK;
  else if (S_ISDIR(raw_mode))
    return S_IFDIR;
  else
    return 0;
}

int git_futils_readbuffer_fd(git_str *buf, git_file fd, size_t len)
{
  ssize_t read_size = 0;
  size_t alloc_len;

  git_str_clear(buf);

  if (!git__is_ssizet(len)) {
    git_error_set(GIT_ERROR_INVALID, "read too large");
    return -1;
  }

  GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, len, 1);
  if (git_str_grow(buf, alloc_len) < 0)
    return -1;

  /* p_read loops internally to read len bytes */
  read_size = p_read(fd, buf->ptr, len);

  if (read_size < 0) {
    git_error_set(GIT_ERROR_OS, "failed to read descriptor");
    git_str_dispose(buf);
    return -1;
  }

  if ((size_t)read_size != len) {
    git_error_set(GIT_ERROR_FILESYSTEM, "could not read (expected %" PRIuZ " bytes, read %" PRIuZ ")", len, (size_t)read_size);
    git_str_dispose(buf);
    return -1;
  }

  buf->ptr[read_size] = '\0';
  buf->size = read_size;

  return 0;
}

int git_futils_readbuffer_fd_full(git_str *buf, git_file fd)
{
  static size_t blocksize = 10240;
  size_t alloc_len = 0, total_size = 0;
  ssize_t read_size = 0;

  git_str_clear(buf);

  while (true) {
    GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, blocksize);

    if (git_str_grow(buf, alloc_len) < 0)
      return -1;

    /* p_read loops internally to read blocksize bytes */
    read_size = p_read(fd, buf->ptr, blocksize);

    if (read_size < 0) {
      git_error_set(GIT_ERROR_OS, "failed to read descriptor");
      git_str_dispose(buf);
      return -1;
    }

    total_size += read_size;

    if ((size_t)read_size < blocksize) {
      break;
    }
  }

  buf->ptr[total_size] = '\0';
  buf->size = total_size;

  return 0;
}

int git_futils_readbuffer_updated(
  git_str *out,
  const char *path,
  unsigned char checksum[GIT_HASH_SHA256_SIZE],
  int *updated)
{
  int error;
  git_file fd;
  struct stat st;
  git_str buf = GIT_STR_INIT;
  unsigned char checksum_new[GIT_HASH_SHA256_SIZE];

  GIT_ASSERT_ARG(out);
  GIT_ASSERT_ARG(path && *path);

  if (updated != NULL)
    *updated = 0;

  if (p_stat(path, &st) < 0)
    return git_fs_path_set_error(errno, path, "stat");


  if (S_ISDIR(st.st_mode)) {
    git_error_set(GIT_ERROR_INVALID, "requested file is a directory");
    return GIT_ENOTFOUND;
  }

  if (!git__is_sizet(st.st_size+1)) {
    git_error_set(GIT_ERROR_OS, "invalid regular file stat for '%s'", path);
    return -1;
  }

  if ((fd = git_futils_open_ro(path)) < 0)
    return fd;

  if (git_futils_readbuffer_fd(&buf, fd, (size_t)st.st_size) < 0) {
    p_close(fd);
    return -1;
  }

  p_close(fd);

  if (checksum) {
    error = git_hash_buf(checksum_new, buf.ptr,
                         buf.size, GIT_HASH_ALGORITHM_SHA256);

    if (error < 0) {
      git_str_dispose(&buf);
      return error;
    }

    /*
     * If we were given a checksum, we only want to use it if it's different
     */
    if (!memcmp(checksum, checksum_new, GIT_HASH_SHA256_SIZE)) {
      git_str_dispose(&buf);
      if (updated)
        *updated = 0;

      return 0;
    }

    memcpy(checksum, checksum_new, GIT_HASH_SHA256_SIZE);
  }

  /*
   * If we're here, the file did change, or the user didn't have an old version
   */
  if (updated != NULL)
    *updated = 1;

  git_str_swap(out, &buf);
  git_str_dispose(&buf);

  return 0;
}

int git_futils_readbuffer(git_str *buf, const char *path)
{
  return git_futils_readbuffer_updated(buf, path, NULL, NULL);
}

int git_futils_writebuffer(
  const git_str *buf, const char *path, int flags, mode_t mode)
{
  int fd, do_fsync = 0, error = 0;

  if (!flags)
    flags = O_CREAT | O_TRUNC | O_WRONLY;

  if ((flags & O_FSYNC) != 0)
    do_fsync = 1;

  flags &= ~O_FSYNC;

  if (!mode)
    mode = GIT_FILEMODE_DEFAULT;

  if ((fd = p_open(path, flags, mode)) < 0) {
    git_error_set(GIT_ERROR_OS, "could not open '%s' for writing", path);
    return fd;
  }

  if ((error = p_write(fd, git_str_cstr(buf), git_str_len(buf))) < 0) {
    git_error_set(GIT_ERROR_OS, "could not write to '%s'", path);
    (void)p_close(fd);
    return error;
  }

  if (do_fsync && (error = p_fsync(fd)) < 0) {
    git_error_set(GIT_ERROR_OS, "could not fsync '%s'", path);
    p_close(fd);
    return error;
  }

  if ((error = p_close(fd)) < 0) {
    git_error_set(GIT_ERROR_OS, "error while closing '%s'", path);
    return error;
  }

  if (do_fsync && (flags & O_CREAT))
    error = git_futils_fsync_parent(path);

  return error;
}

int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode)
{
  if (git_futils_mkpath2file(to, dirmode) < 0)
    return -1;

  if (p_rename(from, to) < 0) {
    git_error_set(GIT_ERROR_OS, "failed to rename '%s' to '%s'", from, to);
    return -1;
  }

  return 0;
}

int git_futils_mmap_ro(git_map *out, git_file fd, off64_t begin, size_t len)
{
  return p_mmap(out, len, GIT_PROT_READ, GIT_MAP_SHARED, fd, begin);
}

int git_futils_mmap_ro_file(git_map *out, const char *path)
{
  git_file fd = git_futils_open_ro(path);
  uint64_t len;
  int result;

  if (fd < 0)
    return fd;

  if ((result = git_futils_filesize(&len, fd)) < 0)
    goto out;

  if (!git__is_sizet(len)) {
    git_error_set(GIT_ERROR_OS, "file `%s` too large to mmap", path);
    result = -1;
    goto out;
  }

  result = git_futils_mmap_ro(out, fd, 0, (size_t)len);
out:
  p_close(fd);
  return result;
}

void git_futils_mmap_free(git_map *out)
{
  p_munmap(out);
}

GIT_INLINE(int) mkdir_validate_dir(
  const char *path,
  struct stat *st,
  mode_t mode,
  uint32_t flags,
  struct git_futils_mkdir_options *opts)
{
  /* with exclusive create, existing dir is an error */
  if ((flags & GIT_MKDIR_EXCL) != 0) {
    git_error_set(GIT_ERROR_FILESYSTEM,
      "failed to make directory '%s': directory exists", path);
    return GIT_EEXISTS;
  }

  if ((S_ISREG(st->st_mode) && (flags & GIT_MKDIR_REMOVE_FILES)) ||
    (S_ISLNK(st->st_mode) && (flags & GIT_MKDIR_REMOVE_SYMLINKS))) {
    if (p_unlink(path) < 0) {
      git_error_set(GIT_ERROR_OS, "failed to remove %s '%s'",
        S_ISLNK(st->st_mode) ? "symlink" : "file", path);
      return GIT_EEXISTS;
    }

    opts->perfdata.mkdir_calls++;

    if (p_mkdir(path, mode) < 0) {
      git_error_set(GIT_ERROR_OS, "failed to make directory '%s'", path);
      return GIT_EEXISTS;
    }
  }

  else if (S_ISLNK(st->st_mode)) {
    /* Re-stat the target, make sure it's a directory */
    opts->perfdata.stat_calls++;

    if (p_stat(path, st) < 0) {
      git_error_set(GIT_ERROR_OS, "failed to make directory '%s'", path);
      return GIT_EEXISTS;
    }
  }

  else if (!S_ISDIR(st->st_mode)) {
    git_error_set(GIT_ERROR_FILESYSTEM,
      "failed to make directory '%s': directory exists", path);
    return GIT_EEXISTS;
  }

  return 0;
}

GIT_INLINE(int) mkdir_validate_mode(
  const char *path,
  struct stat *st,
  bool terminal_path,
  mode_t mode,
  uint32_t flags,
  struct git_futils_mkdir_options *opts)
{
  if (((terminal_path && (flags & GIT_MKDIR_CHMOD) != 0) ||
    (flags & GIT_MKDIR_CHMOD_PATH) != 0) && st->st_mode != mode) {

    opts->perfdata.chmod_calls++;

    if (p_chmod(path, mode) < 0) {
      git_error_set(GIT_ERROR_OS, "failed to set permissions on '%s'", path);
      return -1;
    }
  }

  return 0;
}

GIT_INLINE(int) mkdir_canonicalize(
  git_str *path,
  uint32_t flags)
{
  ssize_t root_len;

  if (path->size == 0) {
    git_error_set(GIT_ERROR_OS, "attempt to create empty path");
    return -1;
  }

  /* Trim trailing slashes (except the root) */
  if ((root_len = git_fs_path_root(path->ptr)) < 0)
    root_len = 0;
  else
    root_len++;

  while (path->size > (size_t)root_len && path->ptr[path->size - 1] == '/')
    path->ptr[--path->size] = '\0';

  /* if we are not supposed to made the last element, truncate it */
  if ((flags & GIT_MKDIR_SKIP_LAST2) != 0) {
    git_fs_path_dirname_r(path, path->ptr);
    flags |= GIT_MKDIR_SKIP_LAST;
  }
  if ((flags & GIT_MKDIR_SKIP_LAST) != 0) {
    git_fs_path_dirname_r(path, path->ptr);
  }

  /* We were either given the root path (or trimmed it to
  * the root), we don't have anything to do.
  */
  if (path->size <= (size_t)root_len)
    git_str_clear(path);

  return 0;
}

int git_futils_mkdir(
  const char *path,
  mode_t mode,
  uint32_t flags)
{
  git_str make_path = GIT_STR_INIT, parent_path = GIT_STR_INIT;
  const char *relative;
  struct git_futils_mkdir_options opts = { 0 };
  struct stat st;
  size_t depth = 0;
  int len = 0, root_len, error;

  if ((error = git_str_puts(&make_path, path)) < 0 ||
    (error = mkdir_canonicalize(&make_path, flags)) < 0 ||
    (error = git_str_puts(&parent_path, make_path.ptr)) < 0 ||
    make_path.size == 0)
    goto done;

  root_len = git_fs_path_root(make_path.ptr);

  /* find the first parent directory that exists.  this will be used
   * as the base to dirname_relative.
   */
  for (relative = make_path.ptr; parent_path.size; ) {
    error = p_lstat(parent_path.ptr, &st);

    if (error == 0) {
      break;
    } else if (errno != ENOENT) {
      git_error_set(GIT_ERROR_OS, "failed to stat '%s'", parent_path.ptr);
      error = -1;
      goto done;
    }

    depth++;

    /* examine the parent of the current path */
    if ((len = git_fs_path_dirname_r(&parent_path, parent_path.ptr)) < 0) {
      error = len;
      goto done;
    }

    GIT_ASSERT(len);

    /*
     * We've walked all the given path's parents and it's either relative
     * (the parent is simply '.') or rooted (the length is less than or
     * equal to length of the root path).  The path may be less than the
     * root path length on Windows, where `C:` == `C:/`.
     */
    if ((len == 1 && parent_path.ptr[0] == '.') ||
        (len == 1 && parent_path.ptr[0] == '/') ||
        len <= root_len) {
      relative = make_path.ptr;
      break;
    }

    relative = make_path.ptr + len + 1;

    /* not recursive? just make this directory relative to its parent. */
    if ((flags & GIT_MKDIR_PATH) == 0)
      break;
  }

  /* we found an item at the location we're trying to create,
   * validate it.
   */
  if (depth == 0) {
    error = mkdir_validate_dir(make_path.ptr, &st, mode, flags, &opts);

    if (!error)
      error = mkdir_validate_mode(
        make_path.ptr, &st, true, mode, flags, &opts);

    goto done;
  }

  /* we already took `SKIP_LAST` and `SKIP_LAST2` into account when
   * canonicalizing `make_path`.
   */
  flags &= ~(GIT_MKDIR_SKIP_LAST2 | GIT_MKDIR_SKIP_LAST);

  error = git_futils_mkdir_relative(relative,
    parent_path.size ? parent_path.ptr : NULL, mode, flags, &opts);

done:
  git_str_dispose(&make_path);
  git_str_dispose(&parent_path);
  return error;
}

int git_futils_mkdir_r(const char *path, const mode_t mode)
{
  return git_futils_mkdir(path, mode, GIT_MKDIR_PATH);
}

int git_futils_mkdir_relative(
  const char *relative_path,
  const char *base,
  mode_t mode,
  uint32_t flags,
  struct git_futils_mkdir_options *opts)
{
  git_str make_path = GIT_STR_INIT;
  ssize_t root = 0, min_root_len;
  char lastch = '/', *tail;
  struct stat st;
  struct git_futils_mkdir_options empty_opts = {0};
  int error;

  if (!opts)
    opts = &empty_opts;

  /* build path and find "root" where we should start calling mkdir */
  if (git_fs_path_join_unrooted(&make_path, relative_path, base, &root) < 0)
    return -1;

  if ((error = mkdir_canonicalize(&make_path, flags)) < 0 ||
    make_path.size == 0)
    goto done;

  /* if we are not supposed to make the whole path, reset root */
  if ((flags & GIT_MKDIR_PATH) == 0)
    root = git_str_rfind(&make_path, '/');

  /* advance root past drive name or network mount prefix */
  min_root_len = git_fs_path_root(make_path.ptr);
  if (root < min_root_len)
    root = min_root_len;
  while (root >= 0 && make_path.ptr[root] == '/')
    ++root;

  /* clip root to make_path length */
  if (root > (ssize_t)make_path.size)
    root = (ssize_t)make_path.size; /* i.e. NUL byte of string */
  if (root < 0)
    root = 0;

  /* walk down tail of path making each directory */
  for (tail = &make_path.ptr[root]; *tail; *tail = lastch) {
    bool mkdir_attempted = false;

    /* advance tail to include next path component */
    while (*tail == '/')
      tail++;
    while (*tail && *tail != '/')
      tail++;

    /* truncate path at next component */
    lastch = *tail;
    *tail = '\0';
    st.st_mode = 0;

    if (opts->cache_pathset &&
        git_hashset_str_contains(opts->cache_pathset, make_path.ptr))
      continue;

    /* See what's going on with this path component */
    opts->perfdata.stat_calls++;

retry_lstat:
    if (p_lstat(make_path.ptr, &st) < 0) {
      if (mkdir_attempted || errno != ENOENT) {
        git_error_set(GIT_ERROR_OS, "cannot access component in path '%s'", make_path.ptr);
        error = -1;
        goto done;
      }

      git_error_clear();
      opts->perfdata.mkdir_calls++;
      mkdir_attempted = true;
      if (p_mkdir(make_path.ptr, mode) < 0) {
        if (errno == EEXIST)
          goto retry_lstat;
        git_error_set(GIT_ERROR_OS, "failed to make directory '%s'", make_path.ptr);
        error = -1;
        goto done;
      }
    } else {
      if ((error = mkdir_validate_dir(
        make_path.ptr, &st, mode, flags, opts)) < 0)
        goto done;
    }

    /* chmod if requested and necessary */
    if ((error = mkdir_validate_mode(
      make_path.ptr, &st, (lastch == '\0'), mode, flags, opts)) < 0)
      goto done;

    if (opts->cache_pathset && opts->cache_pool) {
      char *cache_path;
      size_t alloc_size;

      GIT_ERROR_CHECK_ALLOC_ADD(&alloc_size, make_path.size, 1);
      cache_path = git_pool_malloc(opts->cache_pool, alloc_size);
      GIT_ERROR_CHECK_ALLOC(cache_path);

      memcpy(cache_path, make_path.ptr, make_path.size + 1);

      if ((error = git_hashset_str_add(opts->cache_pathset, cache_path)) < 0)
        goto done;
    }
  }

  error = 0;

  /* check that full path really is a directory if requested & needed */
  if ((flags & GIT_MKDIR_VERIFY_DIR) != 0 &&
    lastch != '\0') {
    opts->perfdata.stat_calls++;

    if (p_stat(make_path.ptr, &st) < 0 || !S_ISDIR(st.st_mode)) {
      git_error_set(GIT_ERROR_OS, "path is not a directory '%s'",
        make_path.ptr);
      error = GIT_ENOTFOUND;
    }
  }

done:
  git_str_dispose(&make_path);
  return error;
}

typedef struct {
  const char *base;
  size_t baselen;
  uint32_t flags;
  int depth;
} futils__rmdir_data;

#define FUTILS_MAX_DEPTH 100

static int futils__error_cannot_rmdir(const char *path, const char *filemsg)
{
  if (filemsg)
    git_error_set(GIT_ERROR_OS, "could not remove directory '%s': %s",
           path, filemsg);
  else
    git_error_set(GIT_ERROR_OS, "could not remove directory '%s'", path);

  return -1;
}

static int futils__rm_first_parent(git_str *path, const char *ceiling)
{
  int error = GIT_ENOTFOUND;
  struct stat st;

  while (error == GIT_ENOTFOUND) {
    git_str_rtruncate_at_char(path, '/');

    if (!path->size || git__prefixcmp(path->ptr, ceiling) != 0)
      error = 0;
    else if (p_lstat_posixly(path->ptr, &st) == 0) {
      if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))
        error = p_unlink(path->ptr);
      else if (!S_ISDIR(st.st_mode))
        error = -1; /* fail to remove non-regular file */
    } else if (errno != ENOTDIR)
      error = -1;
  }

  if (error)
    futils__error_cannot_rmdir(path->ptr, "cannot remove parent");

  return error;
}

static int futils__rmdir_recurs_foreach(void *opaque, git_str *path)
{
  int error = 0;
  futils__rmdir_data *data = opaque;
  struct stat st;

  if (data->depth > FUTILS_MAX_DEPTH)
    error = futils__error_cannot_rmdir(
      path->ptr, "directory nesting too deep");

  else if ((error = p_lstat_posixly(path->ptr, &st)) < 0) {
    if (errno == ENOENT)
      error = 0;
    else if (errno == ENOTDIR) {
      /* asked to remove a/b/c/d/e and a/b is a normal file */
      if ((data->flags & GIT_RMDIR_REMOVE_BLOCKERS) != 0)
        error = futils__rm_first_parent(path, data->base);
      else
        futils__error_cannot_rmdir(
          path->ptr, "parent is not directory");
    }
    else
      error = git_fs_path_set_error(errno, path->ptr, "rmdir");
  }

  else if (S_ISDIR(st.st_mode)) {
    data->depth++;

    error = git_fs_path_direach(path, 0, futils__rmdir_recurs_foreach, data);

    data->depth--;

    if (error < 0)
      return error;

    if (data->depth == 0 && (data->flags & GIT_RMDIR_SKIP_ROOT) != 0)
      return error;

    if ((error = p_rmdir(path->ptr)) < 0) {
      if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) != 0 &&
        (errno == ENOTEMPTY || errno == EEXIST || errno == EBUSY))
        error = 0;
      else
        error = git_fs_path_set_error(errno, path->ptr, "rmdir");
    }
  }

  else if ((data->flags & GIT_RMDIR_REMOVE_FILES) != 0) {
    if (p_unlink(path->ptr) < 0)
      error = git_fs_path_set_error(errno, path->ptr, "remove");
  }

  else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0)
    error = futils__error_cannot_rmdir(path->ptr, "still present");

  return error;
}

static int futils__rmdir_empty_parent(void *opaque, const char *path)
{
  futils__rmdir_data *data = opaque;
  int error = 0;

  if (strlen(path) <= data->baselen)
    error = GIT_ITEROVER;

  else if (p_rmdir(path) < 0) {
    int en = errno;

    if (en == ENOENT || en == ENOTDIR) {
      /* do nothing */
    } else if ((data->flags & GIT_RMDIR_SKIP_NONEMPTY) == 0 &&
      en == EBUSY) {
      error = git_fs_path_set_error(errno, path, "rmdir");
    } else if (en == ENOTEMPTY || en == EEXIST || en == EBUSY) {
      error = GIT_ITEROVER;
    } else {
      error = git_fs_path_set_error(errno, path, "rmdir");
    }
  }

  return error;
}

int git_futils_rmdir_r(
  const char *path, const char *base, uint32_t flags)
{
  int error;
  git_str fullpath = GIT_STR_INIT;
  futils__rmdir_data data;

  /* build path and find "root" where we should start calling mkdir */
  if (git_fs_path_join_unrooted(&fullpath, path, base, NULL) < 0)
    return -1;

  memset(&data, 0, sizeof(data));
  data.base    = base ? base : "";
  data.baselen = base ? strlen(base) : 0;
  data.flags   = flags;

  error = futils__rmdir_recurs_foreach(&data, &fullpath);

  /* remove now-empty parents if requested */
  if (!error && (flags & GIT_RMDIR_EMPTY_PARENTS) != 0)
    error = git_fs_path_walk_up(
      &fullpath, base, futils__rmdir_empty_parent, &data);

  if (error == GIT_ITEROVER) {
    git_error_clear();
    error = 0;
  }

  git_str_dispose(&fullpath);

  return error;
}

int git_futils_fake_symlink(const char *target, const char *path)
{
  int retcode = GIT_ERROR;
  int fd = git_futils_creat_withpath(path, 0755, 0644);
  if (fd >= 0) {
    retcode = p_write(fd, target, strlen(target));
    p_close(fd);
  }
  return retcode;
}

static int cp_by_fd(int ifd, int ofd, bool close_fd_when_done)
{
  int error = 0;
  char buffer[GIT_BUFSIZE_FILEIO];
  ssize_t len = 0;

  while (!error && (len = p_read(ifd, buffer, sizeof(buffer))) > 0)
    /* p_write() does not have the same semantics as write().  It loops
     * internally and will return 0 when it has completed writing.
     */
    error = p_write(ofd, buffer, len);

  if (len < 0) {
    git_error_set(GIT_ERROR_OS, "read error while copying file");
    error = (int)len;
  }

  if (error < 0)
    git_error_set(GIT_ERROR_OS, "write error while copying file");

  if (close_fd_when_done) {
    p_close(ifd);
    p_close(ofd);
  }

  return error;
}

int git_futils_cp(const char *from, const char *to, mode_t filemode)
{
  int ifd, ofd;

  if ((ifd = git_futils_open_ro(from)) < 0)
    return ifd;

  if ((ofd = p_open(to, O_WRONLY | O_CREAT | O_EXCL, filemode)) < 0) {
    p_close(ifd);
    return git_fs_path_set_error(errno, to, "open for writing");
  }

  return cp_by_fd(ifd, ofd, true);
}

int git_futils_touch(const char *path, time_t *when)
{
  struct p_timeval times[2];
  int ret;

  times[0].tv_sec =  times[1].tv_sec  = when ? *when : time(NULL);
  times[0].tv_usec = times[1].tv_usec = 0;

  ret = p_utimes(path, times);

  return (ret < 0) ? git_fs_path_set_error(errno, path, "touch") : 0;
}

static int cp_link(const char *from, const char *to, size_t link_size)
{
  int error = 0;
  ssize_t read_len;
  char *link_data;
  size_t alloc_size;

  GIT_ERROR_CHECK_ALLOC_ADD(&alloc_size, link_size, 1);
  link_data = git__malloc(alloc_size);
  GIT_ERROR_CHECK_ALLOC(link_data);

  read_len = p_readlink(from, link_data, link_size);
  if (read_len != (ssize_t)link_size) {
    git_error_set(GIT_ERROR_OS, "failed to read symlink data for '%s'", from);
    error = -1;
  }
  else {
    link_data[read_len] = '\0';

    if (p_symlink(link_data, to) < 0) {
      git_error_set(GIT_ERROR_OS, "could not symlink '%s' as '%s'",
        link_data, to);
      error = -1;
    }
  }

  git__free(link_data);
  return error;
}

typedef struct {
  const char *to_root;
  git_str to;
  ssize_t from_prefix;
  uint32_t flags;
  uint32_t mkdir_flags;
  mode_t dirmode;
} cp_r_info;

#define GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT (1u << 10)

static int _cp_r_mkdir(cp_r_info *info, git_str *from)
{
  int error = 0;

  /* create root directory the first time we need to create a directory */
  if ((info->flags & GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT) == 0) {
    error = git_futils_mkdir(
      info->to_root, info->dirmode,
      (info->flags & GIT_CPDIR_CHMOD_DIRS) ? GIT_MKDIR_CHMOD : 0);

    info->flags |= GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT;
  }

  /* create directory with root as base to prevent excess chmods */
  if (!error)
    error = git_futils_mkdir_relative(
      from->ptr + info->from_prefix, info->to_root,
      info->dirmode, info->mkdir_flags, NULL);

  return error;
}

static int _cp_r_callback(void *ref, git_str *from)
{
  int error = 0;
  cp_r_info *info = ref;
  struct stat from_st, to_st;
  bool exists = false;

  if ((info->flags & GIT_CPDIR_COPY_DOTFILES) == 0 &&
    from->ptr[git_fs_path_basename_offset(from)] == '.')
    return 0;

  if ((error = git_str_joinpath(
      &info->to, info->to_root, from->ptr + info->from_prefix)) < 0)
    return error;

  if (!(error = git_fs_path_lstat(info->to.ptr, &to_st)))
    exists = true;
  else if (error != GIT_ENOTFOUND)
    return error;
  else {
    git_error_clear();
    error = 0;
  }

  if ((error = git_fs_path_lstat(from->ptr, &from_st)) < 0)
    return error;

  if (S_ISDIR(from_st.st_mode)) {
    mode_t oldmode = info->dirmode;

    /* if we are not chmod'ing, then overwrite dirmode */
    if ((info->flags & GIT_CPDIR_CHMOD_DIRS) == 0)
      info->dirmode = from_st.st_mode;

    /* make directory now if CREATE_EMPTY_DIRS is requested and needed */
    if (!exists && (info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) != 0)
      error = _cp_r_mkdir(info, from);

    /* recurse onto target directory */
    if (!error && (!exists || S_ISDIR(to_st.st_mode)))
      error = git_fs_path_direach(from, 0, _cp_r_callback, info);

    if (oldmode != 0)
      info->dirmode = oldmode;

    return error;
  }

  if (exists) {
    if ((info->flags & GIT_CPDIR_OVERWRITE) == 0)
      return 0;

    if (p_unlink(info->to.ptr) < 0) {
      git_error_set(GIT_ERROR_OS, "cannot overwrite existing file '%s'",
        info->to.ptr);
      return GIT_EEXISTS;
    }
  }

  /* Done if this isn't a regular file or a symlink */
  if (!S_ISREG(from_st.st_mode) &&
    (!S_ISLNK(from_st.st_mode) ||
     (info->flags & GIT_CPDIR_COPY_SYMLINKS) == 0))
    return 0;

  /* Make container directory on demand if needed */
  if ((info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0 &&
    (error = _cp_r_mkdir(info, from)) < 0)
    return error;

  /* make symlink or regular file */
  if (info->flags & GIT_CPDIR_LINK_FILES) {
    if ((error = p_link(from->ptr, info->to.ptr)) < 0)
      git_error_set(GIT_ERROR_OS, "failed to link '%s'", from->ptr);
  } else if (S_ISLNK(from_st.st_mode)) {
    error = cp_link(from->ptr, info->to.ptr, (size_t)from_st.st_size);
  } else {
    mode_t usemode = from_st.st_mode;

    if ((info->flags & GIT_CPDIR_SIMPLE_TO_MODE) != 0)
      usemode = GIT_PERMS_FOR_WRITE(usemode);

    error = git_futils_cp(from->ptr, info->to.ptr, usemode);
  }

  return error;
}

int git_futils_cp_r(
  const char *from,
  const char *to,
  uint32_t flags,
  mode_t dirmode)
{
  int error;
  git_str path = GIT_STR_INIT;
  cp_r_info info;

  if (git_str_joinpath(&path, from, "") < 0) /* ensure trailing slash */
    return -1;

  memset(&info, 0, sizeof(info));
  info.to_root = to;
  info.flags   = flags;
  info.dirmode = dirmode;
  info.from_prefix = path.size;
  git_str_init(&info.to, 0);

  /* precalculate mkdir flags */
  if ((flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0) {
    /* if not creating empty dirs, then use mkdir to create the path on
     * demand right before files are copied.
     */
    info.mkdir_flags = GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST;
    if ((flags & GIT_CPDIR_CHMOD_DIRS) != 0)
      info.mkdir_flags |= GIT_MKDIR_CHMOD_PATH;
  } else {
    /* otherwise, we will do simple mkdir as directories are encountered */
    info.mkdir_flags =
      ((flags & GIT_CPDIR_CHMOD_DIRS) != 0) ? GIT_MKDIR_CHMOD : 0;
  }

  error = _cp_r_callback(&info, &path);

  git_str_dispose(&path);
  git_str_dispose(&info.to);

  return error;
}

int git_futils_filestamp_check(
  git_futils_filestamp *stamp, const char *path)
{
  struct stat st;

  /* if the stamp is NULL, then always reload */
  if (stamp == NULL)
    return 1;

  if (p_stat(path, &st) < 0)
    return GIT_ENOTFOUND;

  if (stamp->mtime.tv_sec == st.st_mtime &&
#if defined(GIT_NSEC)
    stamp->mtime.tv_nsec == st.st_mtime_nsec &&
#endif
    stamp->size  == (uint64_t)st.st_size   &&
    stamp->ino   == (unsigned int)st.st_ino)
    return 0;

  stamp->mtime.tv_sec = st.st_mtime;
#if defined(GIT_NSEC)
  stamp->mtime.tv_nsec = st.st_mtime_nsec;
#endif
  stamp->size  = (uint64_t)st.st_size;
  stamp->ino   = (unsigned int)st.st_ino;

  return 1;
}

void git_futils_filestamp_set(
  git_futils_filestamp *target, const git_futils_filestamp *source)
{
  if (source)
    memcpy(target, source, sizeof(*target));
  else
    memset(target, 0, sizeof(*target));
}


void git_futils_filestamp_set_from_stat(
  git_futils_filestamp *stamp, struct stat *st)
{
  if (st) {
    stamp->mtime.tv_sec = st->st_mtime;
#if defined(GIT_NSEC)
    stamp->mtime.tv_nsec = st->st_mtime_nsec;
#else
    stamp->mtime.tv_nsec = 0;
#endif
    stamp->size  = (uint64_t)st->st_size;
    stamp->ino   = (unsigned int)st->st_ino;
  } else {
    memset(stamp, 0, sizeof(*stamp));
  }
}

int git_futils_fsync_dir(const char *path)
{
#ifdef GIT_WIN32
  GIT_UNUSED(path);
  return 0;
#else
  int fd, error = -1;

  if ((fd = p_open(path, O_RDONLY)) < 0) {
    git_error_set(GIT_ERROR_OS, "failed to open directory '%s' for fsync", path);
    return -1;
  }

  if ((error = p_fsync(fd)) < 0)
    git_error_set(GIT_ERROR_OS, "failed to fsync directory '%s'", path);

  p_close(fd);
  return error;
#endif
}

int git_futils_fsync_parent(const char *path)
{
  char *parent;
  int error;

  if ((parent = git_fs_path_dirname(path)) == NULL)
    return -1;

  error = git_futils_fsync_dir(parent);
  git__free(parent);
  return error;
}

Coverage Report

Created: 2025-06-09 06:06