diff options
Diffstat (limited to 'shared/nm-utils/nm-io-utils.c')
| -rw-r--r-- | shared/nm-utils/nm-io-utils.c | 430 |
1 files changed, 0 insertions, 430 deletions
diff --git a/shared/nm-utils/nm-io-utils.c b/shared/nm-utils/nm-io-utils.c deleted file mode 100644 index 88cb13ff..00000000 --- a/shared/nm-utils/nm-io-utils.c +++ /dev/null @@ -1,430 +0,0 @@ -/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ -/* NetworkManager -- Network link manager - * - * This 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 of the License, or (at your option) any later version. - * - * This 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 this library; if not, write to the - * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, - * Boston, MA 02110-1301 USA. - * - * (C) Copyright 2018 Red Hat, Inc. - */ - -#include "nm-default.h" - -#include "nm-io-utils.h" - -#include <sys/types.h> -#include <sys/stat.h> -#include <fcntl.h> - -#include "nm-shared-utils.h" -#include "nm-secret-utils.h" - -/*****************************************************************************/ - -_nm_printf (3, 4) -static int -_get_contents_error (GError **error, int errsv, const char *format, ...) -{ - if (errsv < 0) - errsv = -errsv; - else if (!errsv) - errsv = errno; - - if (error) { - char *msg; - va_list args; - - va_start (args, format); - msg = g_strdup_vprintf (format, args); - va_end (args); - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "%s: %s", - msg, g_strerror (errsv)); - g_free (msg); - } - return -errsv; -} - -static char * -_mem_realloc (char *old, gboolean do_bzero_mem, gsize cur_len, gsize new_len) -{ - char *new; - - /* re-allocating to zero bytes is an odd case. We don't need it - * and it's not supported. */ - nm_assert (new_len > 0); - - /* regardless of success/failure, @old will always be freed/consumed. */ - - if (do_bzero_mem && cur_len > 0) { - new = g_try_malloc (new_len); - if (new) - memcpy (new, old, NM_MIN (cur_len, new_len)); - nm_explicit_bzero (old, cur_len); - g_free (old); - } else { - new = g_try_realloc (old, new_len); - if (!new) - g_free (old); - } - - return new; -} - -/** - * nm_utils_fd_get_contents: - * @fd: open file descriptor to read. The fd will not be closed, - * but don't rely on its state afterwards. - * @close_fd: if %TRUE, @fd will be closed by the function. - * Passing %TRUE here might safe a syscall for dup(). - * @max_length: allocate at most @max_length bytes. If the - * file is larger, reading will fail. Set to zero to use - * a very large default. - * WARNING: @max_length is here to avoid a crash for huge/unlimited files. - * For example, stat(/sys/class/net/enp0s25/ifindex) gives a filesize of - * 4K, although the actual real is small. @max_length is the memory - * allocated in the process of reading the file, thus it must be at least - * the size reported by fstat. - * If you set it to 1K, read will fail because fstat() claims the - * file is larger. - * @flags: %NMUtilsFileGetContentsFlags for reading the file. - * @contents: the output buffer with the file read. It is always - * NUL terminated. The buffer is at most @max_length long, including - * the NUL byte. That is, it reads only files up to a length of - * @max_length - 1 bytes. - * @length: optional output argument of the read file size. - * - * A reimplementation of g_file_get_contents() with a few differences: - * - accepts an open fd, instead of a path name. This allows you to - * use openat(). - * - limits the maxium filesize to max_length. - * - * Returns: a negative error code on failure. - */ -int -nm_utils_fd_get_contents (int fd, - gboolean close_fd, - gsize max_length, - NMUtilsFileGetContentsFlags flags, - char **contents, - gsize *length, - GError **error) -{ - nm_auto_close int fd_keeper = close_fd ? fd : -1; - struct stat stat_buf; - gs_free char *str = NULL; - const bool do_bzero_mem = NM_FLAGS_HAS (flags, NM_UTILS_FILE_GET_CONTENTS_FLAG_SECRET); - - g_return_val_if_fail (fd >= 0, -EINVAL); - g_return_val_if_fail (contents, -EINVAL); - g_return_val_if_fail (!error || !*error, -EINVAL); - - if (fstat (fd, &stat_buf) < 0) - return _get_contents_error (error, 0, "failure during fstat"); - - if (!max_length) { - /* default to a very large size, but not extreme */ - max_length = 2 * 1024 * 1024; - } - - if ( stat_buf.st_size > 0 - && S_ISREG (stat_buf.st_mode)) { - const gsize n_stat = stat_buf.st_size; - ssize_t n_read; - - if (n_stat > max_length - 1) - return _get_contents_error (error, EMSGSIZE, "file too large (%zu+1 bytes with maximum %zu bytes)", n_stat, max_length); - - str = g_try_malloc (n_stat + 1); - if (!str) - return _get_contents_error (error, ENOMEM, "failure to allocate buffer of %zu+1 bytes", n_stat); - - n_read = nm_utils_fd_read_loop (fd, str, n_stat, TRUE); - if (n_read < 0) { - if (do_bzero_mem) - nm_explicit_bzero (str, n_stat); - return _get_contents_error (error, n_read, "error reading %zu bytes from file descriptor", n_stat); - } - str[n_read] = '\0'; - - if (n_read < n_stat) { - if (!(str = _mem_realloc (str, do_bzero_mem, n_stat + 1, n_read + 1))) - return _get_contents_error (error, ENOMEM, "failure to reallocate buffer with %zu bytes", n_read + 1); - } - NM_SET_OUT (length, n_read); - } else { - nm_auto_fclose FILE *f = NULL; - char buf[4096]; - gsize n_have, n_alloc; - int fd2; - - if (fd_keeper >= 0) - fd2 = nm_steal_fd (&fd_keeper); - else { - fd2 = fcntl (fd, F_DUPFD_CLOEXEC, 0); - if (fd2 < 0) - return _get_contents_error (error, 0, "error during dup"); - } - - if (!(f = fdopen (fd2, "r"))) { - nm_close (fd2); - return _get_contents_error (error, 0, "failure during fdopen"); - } - - n_have = 0; - n_alloc = 0; - - while (!feof (f)) { - int errsv; - gsize n_read; - - n_read = fread (buf, 1, sizeof (buf), f); - errsv = errno; - if (ferror (f)) { - if (do_bzero_mem) - nm_explicit_bzero (buf, sizeof (buf)); - return _get_contents_error (error, errsv, "error during fread"); - } - - if ( n_have > G_MAXSIZE - 1 - n_read - || n_have + n_read + 1 > max_length) { - if (do_bzero_mem) - nm_explicit_bzero (buf, sizeof (buf)); - return _get_contents_error (error, EMSGSIZE, "file stream too large (%zu+1 bytes with maximum %zu bytes)", - (n_have > G_MAXSIZE - 1 - n_read) ? G_MAXSIZE : n_have + n_read, - max_length); - } - - if (n_have + n_read + 1 >= n_alloc) { - gsize old_n_alloc = n_alloc; - - if (n_alloc != 0) { - nm_assert (str); - if (n_alloc >= max_length / 2) - n_alloc = max_length; - else - n_alloc *= 2; - } else { - nm_assert (!str); - n_alloc = NM_MIN (n_read + 1, sizeof (buf)); - } - - if (!(str = _mem_realloc (str, do_bzero_mem, old_n_alloc, n_alloc))) { - if (do_bzero_mem) - nm_explicit_bzero (buf, sizeof (buf)); - return _get_contents_error (error, ENOMEM, "failure to allocate buffer of %zu bytes", n_alloc); - } - } - - memcpy (str + n_have, buf, n_read); - n_have += n_read; - } - - if (do_bzero_mem) - nm_explicit_bzero (buf, sizeof (buf)); - - if (n_alloc == 0) - str = g_new0 (char, 1); - else { - str[n_have] = '\0'; - if (n_have + 1 < n_alloc) { - if (!(str = _mem_realloc (str, do_bzero_mem, n_alloc, n_have + 1))) - return _get_contents_error (error, ENOMEM, "failure to truncate buffer to %zu bytes", n_have + 1); - } - } - - NM_SET_OUT (length, n_have); - } - - *contents = g_steal_pointer (&str); - return 0; -} - -/** - * nm_utils_file_get_contents: - * @dirfd: optional file descriptor to use openat(). If negative, use plain open(). - * @filename: the filename to open. Possibly relative to @dirfd. - * @max_length: allocate at most @max_length bytes. - * WARNING: see nm_utils_fd_get_contents() hint about @max_length. - * @flags: %NMUtilsFileGetContentsFlags for reading the file. - * @contents: the output buffer with the file read. It is always - * NUL terminated. The buffer is at most @max_length long, including - * the NUL byte. That is, it reads only files up to a length of - * @max_length - 1 bytes. - * @length: optional output argument of the read file size. - * - * A reimplementation of g_file_get_contents() with a few differences: - * - accepts an @dirfd to open @filename relative to that path via openat(). - * - limits the maxium filesize to max_length. - * - uses O_CLOEXEC on internal file descriptor - * - * Returns: a negative error code on failure. - */ -int -nm_utils_file_get_contents (int dirfd, - const char *filename, - gsize max_length, - NMUtilsFileGetContentsFlags flags, - char **contents, - gsize *length, - GError **error) -{ - int fd; - int errsv; - - g_return_val_if_fail (filename && filename[0], -EINVAL); - - if (dirfd >= 0) { - fd = openat (dirfd, filename, O_RDONLY | O_CLOEXEC); - if (fd < 0) { - errsv = errno; - - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "Failed to open file \"%s\" with openat: %s", - filename, - g_strerror (errsv)); - return -errsv; - } - } else { - fd = open (filename, O_RDONLY | O_CLOEXEC); - if (fd < 0) { - errsv = errno; - - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "Failed to open file \"%s\": %s", - filename, - g_strerror (errsv)); - return -errsv; - } - } - return nm_utils_fd_get_contents (fd, - TRUE, - max_length, - flags, - contents, - length, - error); -} - -/*****************************************************************************/ - -/* - * Copied from GLib's g_file_set_contents() et al., but allows - * specifying a mode for the new file. - */ -gboolean -nm_utils_file_set_contents (const char *filename, - const char *contents, - gssize length, - mode_t mode, - GError **error) -{ - gs_free char *tmp_name = NULL; - struct stat statbuf; - int errsv; - gssize s; - int fd; - - g_return_val_if_fail (filename, FALSE); - g_return_val_if_fail (contents || !length, FALSE); - g_return_val_if_fail (!error || !*error, FALSE); - g_return_val_if_fail (length >= -1, FALSE); - - if (length == -1) - length = strlen (contents); - - tmp_name = g_strdup_printf ("%s.XXXXXX", filename); - fd = g_mkstemp_full (tmp_name, O_RDWR, mode); - if (fd < 0) { - errsv = errno; - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "failed to create file %s: %s", - tmp_name, - g_strerror (errsv)); - return FALSE; - } - - while (length > 0) { - s = write (fd, contents, length); - if (s < 0) { - errsv = errno; - if (errsv == EINTR) - continue; - - nm_close (fd); - unlink (tmp_name); - - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "failed to write to file %s: %s", - tmp_name, - g_strerror (errsv)); - return FALSE; - } - - g_assert (s <= length); - - contents += s; - length -= s; - } - - /* If the final destination exists and is > 0 bytes, we want to sync the - * newly written file to ensure the data is on disk when we rename over - * the destination. Otherwise if we get a system crash we can lose both - * the new and the old file on some filesystems. (I.E. those that don't - * guarantee the data is written to the disk before the metadata.) - */ - if ( lstat (filename, &statbuf) == 0 - && statbuf.st_size > 0 - && fsync (fd) != 0) { - errsv = errno; - - nm_close (fd); - unlink (tmp_name); - - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "failed to fsync %s: %s", - tmp_name, - g_strerror (errsv)); - return FALSE; - } - - nm_close (fd); - - if (rename (tmp_name, filename)) { - errsv = errno; - unlink (tmp_name); - g_set_error (error, - G_FILE_ERROR, - g_file_error_from_errno (errsv), - "failed to rename %s to %s: %s", - tmp_name, - filename, - g_strerror (errsv)); - return FALSE; - } - - return TRUE; -} |