From 8da7bc93315cb0c32ad868f17808468b81fa76ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Forsman?= <bjorn.forsman@gmail.com>
Date: Wed, 5 Dec 2018 19:52:51 +0100
Subject: [PATCH] Honor the SOURCE_DATE_EPOCH variable
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Implement the SOURCE_DATE_EPOCH specification[1] for reproducible
builds. If SOURCE_DATE_EPOCH is set, use it as timestamp instead of the
current time.
[1] https://reproducible-builds.org/specs/source-date-epoch/
Signed-off-by: Bjørn Forsman <bjorn.forsman@gmail.com>
---
src/boot.c | 23 +++++++++++++++++++++--
src/common.c | 18 ++++++++++++++++--
src/mkfs.fat.c | 19 ++++++++++++++++---
3 files changed, 53 insertions(+), 7 deletions(-)
diff --git a/src/boot.c b/src/boot.c
index 4de450d..8f78e1c 100644
--- a/src/boot.c
+++ b/src/boot.c
@@ -33,6 +33,8 @@
#include <stdlib.h>
#include <sys/types.h>
#include <time.h>
+#include <errno.h>
+#include <ctype.h>
#include "common.h"
#include "fsck.fat.h"
@@ -672,6 +674,7 @@ void write_volume_label(DOS_FS * fs, char *label)
{
time_t now;
struct tm *mtime;
+ char *source_date_epoch = NULL;
off_t offset;
int created;
DIR_ENT de;
@@ -687,8 +690,24 @@ void write_volume_label(DOS_FS * fs, char *label)
if (de.name[0] == 0xe5)
de.name[0] = 0x05;
- now = time(NULL);
- mtime = (now != (time_t)-1) ? localtime(&now) : NULL;
+ source_date_epoch = getenv("SOURCE_DATE_EPOCH");
+ if (source_date_epoch) {
+ char *tmp = NULL;
+ long long conversion = 0;
+ errno = 0;
+ conversion = strtoll(source_date_epoch, &tmp, 10);
+ now = conversion;
+ if (!isdigit((unsigned char)*source_date_epoch) || *tmp != '\0'
+ || errno != 0 || (long long)now != conversion) {
+ die("SOURCE_DATE_EPOCH is too big or contains non-digits: \"%s\"",
+ source_date_epoch);
+ }
+ mtime = gmtime(&now);
+ } else {
+ now = time(NULL);
+ mtime = (now != (time_t)-1) ? localtime(&now) : NULL;
+ }
+
if (mtime && mtime->tm_year >= 80 && mtime->tm_year <= 207) {
de.time = htole16((unsigned short)((mtime->tm_sec >> 1) +
(mtime->tm_min << 5) +
diff --git a/src/common.c b/src/common.c
index 6a2e396..4f1afcb 100644
--- a/src/common.c
+++ b/src/common.c
@@ -30,6 +30,7 @@
#include <string.h>
#include <stdarg.h>
#include <errno.h>
+#include <ctype.h>
#include <wctype.h>
#include <termios.h>
#include <sys/time.h>
@@ -298,8 +299,21 @@ void check_atari(void)
uint32_t generate_volume_id(void)
{
struct timeval now;
-
- if (gettimeofday(&now, NULL) != 0 || now.tv_sec == (time_t)-1 || now.tv_sec < 0) {
+ char *source_date_epoch = NULL;
+
+ source_date_epoch = getenv("SOURCE_DATE_EPOCH");
+ if (source_date_epoch) {
+ char *tmp = NULL;
+ long long conversion = 0;
+ errno = 0;
+ conversion = strtoll(source_date_epoch, &tmp, 10);
+ if (!isdigit((unsigned char)*source_date_epoch) || *tmp != '\0'
+ || errno != 0) {
+ die("SOURCE_DATE_EPOCH is too big or contains non-digits: \"%s\"",
+ source_date_epoch);
+ }
+ return (uint32_t)conversion;
+ } else if (gettimeofday(&now, NULL) != 0 || now.tv_sec == (time_t)-1 || now.tv_sec < 0) {
srand(getpid());
/* rand() returns int from [0,RAND_MAX], therefore only 31 bits */
return (((uint32_t)(rand() & 0xFFFF)) << 16) | ((uint32_t)(rand() & 0xFFFF));
diff --git a/src/mkfs.fat.c b/src/mkfs.fat.c
index 37fc8ff..1948635 100644
--- a/src/mkfs.fat.c
+++ b/src/mkfs.fat.c
@@ -1074,7 +1074,7 @@ static void setup_tables(void)
}
/* If is not available then generate random 32 bit disk signature */
- if (invariant)
+ if (invariant || getenv("SOURCE_DATE_EPOCH"))
disk_sig = volume_id;
else if (!disk_sig)
disk_sig = generate_volume_id();
@@ -1287,7 +1287,7 @@ static void setup_tables(void)
de->name[0] = 0x05;
de->attr = ATTR_VOLUME;
if (create_time != (time_t)-1) {
- if (!invariant)
+ if (!invariant && !getenv("SOURCE_DATE_EPOCH"))
ctime = localtime(&create_time);
else
ctime = gmtime(&create_time);
@@ -1477,6 +1477,7 @@ int main(int argc, char **argv)
int blocks_specified = 0;
struct timeval create_timeval;
long long conversion;
+ char *source_date_epoch = NULL;
enum {OPT_HELP=1000, OPT_INVARIANT, OPT_MBR, OPT_VARIANT, OPT_CODEPAGE, OPT_OFFSET};
const struct option long_options[] = {
@@ -1497,8 +1498,20 @@ int main(int argc, char **argv)
program_name = p + 1;
}
- if (gettimeofday(&create_timeval, NULL) == 0 && create_timeval.tv_sec != (time_t)-1)
+ source_date_epoch = getenv("SOURCE_DATE_EPOCH");
+ if (source_date_epoch) {
+ errno = 0;
+ conversion = strtoll(source_date_epoch, &tmp, 10);
+ create_time = conversion;
+ if (!isdigit((unsigned char)*source_date_epoch) || *tmp != '\0'
+ || errno != 0 || (long long)create_time != conversion) {
+ die("SOURCE_DATE_EPOCH is too big or contains non-digits: \"%s\"",
+ source_date_epoch);
+ }
+ } else if (gettimeofday(&create_timeval, NULL) == 0 && create_timeval.tv_sec != (time_t)-1) {
create_time = create_timeval.tv_sec;
+ }
+
volume_id = generate_volume_id();
check_atari();