From 402fc5a6000bf0ec12f05d4aa2b3e250ec85a60a Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Fri, 2 Aug 2019 11:41:36 +0200 Subject: Implement support for SOURCE_DATE_EPOCH environment variable reproducible-builds.org suggests the use of an environment variable as a source for time stamps: https://reproducible-builds.org/specs/source-date-epoch/ This commit adds support for setting the default mtime from the variable, if it is set and only defaulting to 0 if not. The timestamp given by the command line switch takes precedence. Signed-off-by: David Oberhollenzer --- lib/Makemodule.am | 1 + lib/fstree/fstree.c | 2 ++ lib/util/source_date_epoch.c | 45 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+) create mode 100644 lib/util/source_date_epoch.c (limited to 'lib') diff --git a/lib/Makemodule.am b/lib/Makemodule.am index 5a8ffaa..f49ff91 100644 --- a/lib/Makemodule.am +++ b/lib/Makemodule.am @@ -45,6 +45,7 @@ libutil_a_SOURCES += lib/util/print_version.c lib/util/mkdir_p.c libutil_a_SOURCES += lib/util/str_table.c include/str_table.h libutil_a_SOURCES += lib/util/dirstack.c lib/util/padd_file.c libutil_a_SOURCES += lib/util/read_data_at.c lib/util/crc32.c +libutil_a_SOURCES += lib/util/source_date_epoch.c if WITH_GZIP libcompress_a_SOURCES += lib/comp/gzip.c diff --git a/lib/fstree/fstree.c b/lib/fstree/fstree.c index 3c240e7..6955c17 100644 --- a/lib/fstree/fstree.c +++ b/lib/fstree/fstree.c @@ -7,6 +7,7 @@ #include "config.h" #include "fstree.h" +#include "util.h" #include #include @@ -110,6 +111,7 @@ int fstree_init(fstree_t *fs, size_t block_size, char *defaults) memset(fs, 0, sizeof(*fs)); fs->defaults.st_mode = S_IFDIR | 0755; fs->defaults.st_blksize = block_size; + fs->defaults.st_mtime = get_source_date_epoch(); fs->block_size = block_size; if (defaults != NULL && process_defaults(&fs->defaults, defaults) != 0) diff --git a/lib/util/source_date_epoch.c b/lib/util/source_date_epoch.c new file mode 100644 index 0000000..1397e52 --- /dev/null +++ b/lib/util/source_date_epoch.c @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * source_date_epoch.h + * + * Copyright (C) 2019 David Oberhollenzer + */ +#include "config.h" +#include "util.h" + +#include +#include +#include + +uint32_t get_source_date_epoch(void) +{ + const char *str, *ptr; + uint32_t x, tval = 0; + + str = getenv("SOURCE_DATE_EPOCH"); + + if (str == NULL || *str == '\0') + return 0; + + for (ptr = str; *ptr != '\0'; ++ptr) { + if (!isdigit(*ptr)) + goto fail_nan; + + x = (*ptr) - '0'; + + if (tval > (UINT32_MAX - x) / 10) + goto fail_ov; + + tval = tval * 10 + x; + } + + return tval; +fail_ov: + fprintf(stderr, "WARNING: SOURCE_DATE_EPOCH=%s does not fit into " + "32 bit integer\n", str); + return 0; +fail_nan: + fprintf(stderr, "WARNING: SOURCE_DATE_EPOCH=%s is not a positive " + "number\n", str); + return 0; +} -- cgit v1.2.3