From d1383915089af484e68ae5ce03f5c20e78ad0726 Mon Sep 17 00:00:00 2001
From: Patrick McDermott <patrick.mcdermott@libiquity.com>
Date: Sun, 30 Apr 2023 21:25:55 -0400
Subject: ustar: Move SOURCE_DATE_EPOCH code to opk/write

This way it runs only once (without resorting to static variables)
across all headers in all ustar archives.  Also, opk/write now prints an
informative error message.
---
diff --git a/src/opk/write.c b/src/opk/write.c
index 1b490ee..93ddc74 100644
--- a/src/opk/write.c
+++ b/src/opk/write.c
@@ -20,6 +20,7 @@
 #include <grp.h>
 #include <pwd.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include "../defs.h"
 #include "../dirent.h"
@@ -41,16 +42,41 @@ _opkg_opk_opk_write_file(void *user_data, size_t size)
 	}
 }
 
+static int
+_opkg_opk_opk_source_date_epoch(int64_t *mtime)
+{
+	char *env;
+	char *end;
+
+	env = getenv("SOURCE_DATE_EPOCH");
+	if (env == NULL) {
+		return OPKG_OPK_ERROR;
+	}
+	*mtime = strtol(env, &end, 10);
+	if (*end != '\0') {
+		return OPKG_OPK_ERROR;
+	}
+	return OPKG_OPK_OK;
+}
+
 int
 opkg_opk_opk_write(struct opkg_opk_opk *opk, const char *file_name)
 {
 	int                     ret;
+	int64_t                 mtime;
 	struct opkg_opk_dirent  dirent;
 	char                   *buffer;
 	size_t                  size;
 
 	ret = OPKG_OPK_OK;
 
+	if (_opkg_opk_opk_source_date_epoch(&mtime) == OPKG_OPK_ERROR) {
+		fputs(_("Error: Missing or invalid SOURCE_DATE_EPOCH\n"),
+				stderr);
+		ret = OPKG_OPK_ERROR;
+		goto out0;
+	}
+
 	/* Open outer archive. */
 	opk->file = fopen(file_name, "wb");
 	if (opk->file == NULL) {
@@ -85,7 +111,7 @@ opkg_opk_opk_write(struct opkg_opk_opk *opk, const char *file_name)
 	if (opkg_opk_ustar_write_header(opk->outer_ustar, &dirent, 0644,
 				0, getpwuid(0)->pw_name,
 				0, getgrgid(0)->gr_name,
-				4, '-', NULL) != OPKG_OPK_OK) {
+				4, mtime, '-', NULL) != OPKG_OPK_OK) {
 		fputs(_("Error: Failed to write header\n"), stderr);
 		ret = OPKG_OPK_ERROR;
 		goto out3;
diff --git a/src/ustar.c b/src/ustar.c
index a2ab0f8..88ae7b6 100644
--- a/src/ustar.c
+++ b/src/ustar.c
@@ -265,31 +265,13 @@ opkg_opk_ustar_read(struct opkg_opk_ustar *ustar, char **buffer, size_t *size)
 	return OPKG_OPK_OK;
 }
 
-static int
-_opkg_opk_ustar_source_date_epoch(int64_t *mtime)
-{
-	char *env;
-	char *end;
-
-	env = getenv("SOURCE_DATE_EPOCH");
-	if (env == NULL) {
-		return OPKG_OPK_ERROR;
-	}
-	*mtime = strtol(env, &end, 10);
-	if (*end != '\0') {
-		return OPKG_OPK_ERROR;
-	}
-	return OPKG_OPK_OK;
-}
-
 int
 opkg_opk_ustar_write_header(struct opkg_opk_ustar *ustar,
 		struct opkg_opk_dirent *dirent, uint16_t mode,
 		uid_t uid, const char *uname, gid_t gid, const char *gname,
-		uint64_t size, char type, const char *linkname)
+		uint64_t size, int64_t mtime, char type, const char *linkname)
 {
 	size_t    linkname_len;
-	int64_t   mtime;
 	uint32_t  chksum;
 	size_t    i;
 	char     *header_uc;
@@ -307,6 +289,7 @@ opkg_opk_ustar_write_header(struct opkg_opk_ustar *ustar,
 	strncpy(ustar->header.uname, uname, sizeof(ustar->header.uname));
 	strncpy(ustar->header.gname, gname, sizeof(ustar->header.gname));
 	sprintf(ustar->header.size, "%o", size);
+	sprintf(ustar->header.mtime, "%o", mtime);
 	switch (type) {
 		case '-':  /* Regular file */
 			*ustar->header.typeflag = '0';
@@ -338,11 +321,6 @@ opkg_opk_ustar_write_header(struct opkg_opk_ustar *ustar,
 	memset(ustar->header.linkname, 0,
 			sizeof(ustar->header.linkname) - linkname_len);
 
-	if (_opkg_opk_ustar_source_date_epoch(&mtime) == OPKG_OPK_ERROR) {
-		return OPKG_OPK_ERROR;
-	}
-	sprintf(ustar->header.mtime, "%o", mtime);
-
 	strcpy(ustar->header.magic, "ustar");
 	memcpy(ustar->header.version, "00", 2);
 	chksum = 0;
diff --git a/src/ustar.h b/src/ustar.h
index 679f8ae..4c51070 100644
--- a/src/ustar.h
+++ b/src/ustar.h
@@ -90,7 +90,7 @@ int
 opkg_opk_ustar_write_header(struct opkg_opk_ustar *ustar,
 		struct opkg_opk_dirent *dirent, uint16_t mode,
 		uid_t uid, const char *uname, gid_t gid, const char *gname,
-		uint64_t size, char type, const char *linkname);
+		uint64_t size, int64_t mtime, char type, const char *linkname);
 
 int
 opkg_opk_ustar_get_buffer(struct opkg_opk_ustar *ustar, char **buffer,
--
cgit v0.9.1