github: Update for main branch

[mirror_lxc.git] / src / lxc / parse.c

diff --git a/src/lxc/parse.c b/src/lxc/parse.c
index fcc174a7710ea7f6894a02696cc45978772b614b..c174de96c272eee3ab766cc635ef547ff07d6107 100644 (file)
--- a/src/lxc/parse.c
+++ b/src/lxc/parse.c
@@ -1,39 +1,21 @@
-/*
- * lxc: linux Container library
- *
- * (C) Copyright IBM Corp. 2007, 2008
- *
- * Authors:
- * Daniel Lezcano <daniel.lezcano at free.fr>
- *
- * 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 2.1 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
- */
-
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE 1
-#endif
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "config.h"
+
 #include <dirent.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <sys/sendfile.h>
 
-#include "config.h"
+#include "file_utils.h"
 #include "log.h"
+#include "macro.h"
 #include "parse.h"
+#include "syscall_wrappers.h"
 #include "utils.h"
 
 lxc_log_define(parse, lxc);
@@ -65,62 +47,111 @@ int lxc_strmunmap(void *addr, size_t length)
        return munmap(addr, length + 1);
 }
 
-int lxc_file_for_each_line_mmap(const char *file, lxc_file_cb callback,
-                               void *data)
+int lxc_file_for_each_line_mmap(const char *file, lxc_file_cb callback, void *data)
 {
-       int fd;
-       char *buf, *line;
-       struct stat st;
-       int ret = 0;
+       __do_close int fd = -EBADF, memfd = -EBADF;
+       ssize_t ret = -1;
+       char *buf = NULL;
+       struct stat st = {};
+       ssize_t bytes;
+       char *line;
+
+       memfd = memfd_create(".lxc_config_file", MFD_CLOEXEC);
+       if (memfd < 0) {
+               char template[] = P_tmpdir "/.lxc_config_file_XXXXXX";
+
+               if (errno != ENOSYS) {
+                       SYSERROR("Failed to create memory file");
+                       goto on_error;
+               }
+
+               TRACE("Failed to create in-memory file. Falling back to temporary file");
+               memfd = lxc_make_tmpfile(template, true);
+               if (memfd < 0) {
+                       SYSERROR("Failed to create temporary file \"%s\"", template);
+                       goto on_error;
+               }
+       }
 
        fd = open(file, O_RDONLY | O_CLOEXEC);
-       if (fd < 0)
-               return -1;
+       if (fd < 0) {
+               SYSERROR("Failed to open file \"%s\"", file);
+               goto on_error;
+       }
 
        ret = fstat(fd, &st);
+       if (ret) {
+               SYSERROR("Failed to stat file \"%s\"", file);
+               goto on_error;
+       }
+
+       if (st.st_size > INT_MAX) {
+               SYSERROR("Excessively large config file \"%s\"", file);
+               goto on_error;
+       }
+
+
+       bytes = __fd_to_fd(fd, memfd);
+       if (bytes < 0) {
+               SYSERROR("Failed to copy config file \"%s\"", file);
+               goto on_error;
+       }
+
+       ret = lxc_write_nointr(memfd, "\0", 1);
        if (ret < 0) {
-               close(fd);
-               return -1;
+               SYSERROR("Failed to append zero byte");
+               goto on_error;
        }
+       bytes++;
 
-       if (st.st_size == 0) {
-               close(fd);
-               return 0;
+       ret = lseek(memfd, 0, SEEK_SET);
+       if (ret < 0) {
+               SYSERROR("Failed to lseek");
+               goto on_error;
        }
 
-       buf = lxc_strmmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+       ret = -1;
+       buf = mmap(NULL, bytes, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_POPULATE, memfd, 0);
        if (buf == MAP_FAILED) {
-               close(fd);
-               return -1;
+               buf = NULL;
+               SYSERROR("Failed to mmap");
+               goto on_error;
        }
 
-       lxc_iterate_parts(line, buf, "\n\0") {
+       ret = 0;
+       lxc_iterate_parts(line, buf, "\r\n\0") {
                ret = callback(line, data);
                if (ret) {
                        /* Callback rv > 0 means stop here callback rv < 0 means
                         * error.
                         */
                        if (ret < 0)
-                               ERROR("Failed to parse config: %s", line);
+                               ERROR("Failed to parse config file \"%s\" at line \"%s\"",
+                                     file, line);
                        break;
                }
        }
 
-       lxc_strmunmap(buf, st.st_size);
-       close(fd);
+on_error:
+       if (buf && munmap(buf, bytes)) {
+               SYSERROR("Failed to unmap");
+               if (ret == 0)
+                       ret = -1;
+       }
+
        return ret;
 }
 
 int lxc_file_for_each_line(const char *file, lxc_file_cb callback, void *data)
 {
-       FILE *f;
+       __do_fclose FILE *f = NULL;
+       __do_free char *line = NULL;
        int err = 0;
-       char *line = NULL;
        size_t len = 0;
 
-       f = fopen(file, "r");
+       f = fopen(file, "re");
        if (!f) {
-               SYSERROR("failed to open %s", file);
+               SYSERROR("Failed to open \"%s\"", file);
                return -1;
        }
 
@@ -131,12 +162,10 @@ int lxc_file_for_each_line(const char *file, lxc_file_cb callback, void *data)
                         * error.
                         */
                        if (err < 0)
-                               ERROR("Failed to parse config: %s", line);
+                               ERROR("Failed to parse config: \"%s\"", line);
                        break;
                }
        }
 
-       free(line);
-       fclose(f);
        return err;
 }