1 files changed, 76 insertions, 35 deletions

diff --git a/archive-tar.c b/archive-tar.c
index 0d1e6bd75..c6ed96ee7 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -2,6 +2,7 @@
  * Copyright (c) 2005, 2006 Rene Scharfe
  */
 #include "cache.h"
+#include "config.h"
 #include "tar.h"
 #include "archive.h"
 #include "streaming.h"
@@ -18,6 +19,24 @@ static int tar_umask = 002;
 static int write_tar_filter_archive(const struct archiver *ar,
 				    struct archiver_args *args);
 
+/*
+ * This is the max value that a ustar size header can specify, as it is fixed
+ * at 11 octal digits. POSIX specifies that we switch to extended headers at
+ * this size.
+ *
+ * Likewise for the mtime (which happens to use a buffer of the same size).
+ */
+#if ULONG_MAX == 0xFFFFFFFF
+#define USTAR_MAX_SIZE ULONG_MAX
+#else
+#define USTAR_MAX_SIZE 077777777777UL
+#endif
+#if TIME_MAX == 0xFFFFFFFF
+#define USTAR_MAX_MTIME TIME_MAX
+#else
+#define USTAR_MAX_MTIME 077777777777ULL
+#endif
+
 /* writes out the whole block, but only if it is full */
 static void write_if_needed(void)
 {
@@ -137,6 +156,20 @@ static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
 	strbuf_addch(sb, '\n');
 }
 
+/*
+ * Like strbuf_append_ext_header, but for numeric values.
+ */
+static void strbuf_append_ext_header_uint(struct strbuf *sb,
+					  const char *keyword,
+					  uintmax_t value)
+{
+	char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
+	int len;
+
+	len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
+	strbuf_append_ext_header(sb, keyword, buf, len);
+}
+
 static unsigned int ustar_header_chksum(const struct ustar_header *header)
 {
 	const unsigned char *p = (const unsigned char *)header;
@@ -167,37 +200,36 @@ static void prepare_header(struct archiver_args *args,
 			   struct ustar_header *header,
 			   unsigned int mode, unsigned long size)
 {
-	sprintf(header->mode, "%07o", mode & 07777);
-	sprintf(header->size, "%011lo", S_ISREG(mode) ? size : 0);
-	sprintf(header->mtime, "%011lo", (unsigned long) args->time);
+	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
+	xsnprintf(header->size, sizeof(header->size), "%011lo", S_ISREG(mode) ? size : 0);
+	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
 
-	sprintf(header->uid, "%07o", 0);
-	sprintf(header->gid, "%07o", 0);
+	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
+	xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
 	strlcpy(header->uname, "root", sizeof(header->uname));
 	strlcpy(header->gname, "root", sizeof(header->gname));
-	sprintf(header->devmajor, "%07o", 0);
-	sprintf(header->devminor, "%07o", 0);
+	xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
+	xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
 
 	memcpy(header->magic, "ustar", 6);
 	memcpy(header->version, "00", 2);
 
-	sprintf(header->chksum, "%07o", ustar_header_chksum(header));
+	xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
 }
 
-static int write_extended_header(struct archiver_args *args,
-				 const unsigned char *sha1,
-				 const void *buffer, unsigned long size)
+static void write_extended_header(struct archiver_args *args,
+				  const unsigned char *sha1,
+				  const void *buffer, unsigned long size)
 {
 	struct ustar_header header;
 	unsigned int mode;
 	memset(&header, 0, sizeof(header));
 	*header.typeflag = TYPEFLAG_EXT_HEADER;
 	mode = 0100666;
-	sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
+	xsnprintf(header.name, sizeof(header.name), "%s.paxheader", sha1_to_hex(sha1));
 	prepare_header(args, &header, mode, size);
 	write_blocked(&header, sizeof(header));
 	write_blocked(buffer, size);
-	return 0;
 }
 
 static int write_tar_entry(struct archiver_args *args,
@@ -208,7 +240,7 @@ static int write_tar_entry(struct archiver_args *args,
 	struct ustar_header header;
 	struct strbuf ext_header = STRBUF_INIT;
 	unsigned int old_mode = mode;
-	unsigned long size;
+	unsigned long size, size_in_header;
 	void *buffer;
 	int err = 0;
 
@@ -233,10 +265,10 @@ static int write_tar_entry(struct archiver_args *args,
 		size_t rest = pathlen - plen - 1;
 		if (plen > 0 && rest <= sizeof(header.name)) {
 			memcpy(header.prefix, path, plen);
-				memcpy(header.name, path + plen + 1, rest);
+			memcpy(header.name, path + plen + 1, rest);
 		} else {
-			sprintf(header.name, "%s.data",
-				sha1_to_hex(sha1));
+			xsnprintf(header.name, sizeof(header.name), "%s.data",
+				  sha1_to_hex(sha1));
 			strbuf_append_ext_header(&ext_header, "path",
 						 path, pathlen);
 		}
@@ -259,23 +291,25 @@ static int write_tar_entry(struct archiver_args *args,
 
 	if (S_ISLNK(mode)) {
 		if (size > sizeof(header.linkname)) {
-			sprintf(header.linkname, "see %s.paxheader",
-			        sha1_to_hex(sha1));
+			xsnprintf(header.linkname, sizeof(header.linkname),
+				  "see %s.paxheader", sha1_to_hex(sha1));
 			strbuf_append_ext_header(&ext_header, "linkpath",
 			                         buffer, size);
 		} else
 			memcpy(header.linkname, buffer, size);
 	}
 
-	prepare_header(args, &header, mode, size);
+	size_in_header = size;
+	if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
+		size_in_header = 0;
+		strbuf_append_ext_header_uint(&ext_header, "size", size);
+	}
+
+	prepare_header(args, &header, mode, size_in_header);
 
 	if (ext_header.len > 0) {
-		err = write_extended_header(args, sha1, ext_header.buf,
-					    ext_header.len);
-		if (err) {
-			free(buffer);
-			return err;
-		}
+		write_extended_header(args, sha1, ext_header.buf,
+				      ext_header.len);
 	}
 	strbuf_release(&ext_header);
 	write_blocked(&header, sizeof(header));
@@ -289,24 +323,33 @@ static int write_tar_entry(struct archiver_args *args,
 	return err;
 }
 
-static int write_global_extended_header(struct archiver_args *args)
+static void write_global_extended_header(struct archiver_args *args)
 {
 	const unsigned char *sha1 = args->commit_sha1;
 	struct strbuf ext_header = STRBUF_INIT;
 	struct ustar_header header;
 	unsigned int mode;
-	int err = 0;
 
-	strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
+	if (sha1)
+		strbuf_append_ext_header(&ext_header, "comment",
+					 sha1_to_hex(sha1), 40);
+	if (args->time > USTAR_MAX_MTIME) {
+		strbuf_append_ext_header_uint(&ext_header, "mtime",
+					      args->time);
+		args->time = USTAR_MAX_MTIME;
+	}
+
+	if (!ext_header.len)
+		return;
+
 	memset(&header, 0, sizeof(header));
 	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
 	mode = 0100666;
-	strcpy(header.name, "pax_global_header");
+	xsnprintf(header.name, sizeof(header.name), "pax_global_header");
 	prepare_header(args, &header, mode, ext_header.len);
 	write_blocked(&header, sizeof(header));
 	write_blocked(ext_header.buf, ext_header.len);
 	strbuf_release(&ext_header);
-	return err;
 }
 
 static struct archiver **tar_filters;
@@ -382,10 +425,8 @@ static int write_tar_archive(const struct archiver *ar,
 {
 	int err = 0;
 
-	if (args->commit_sha1)
-		err = write_global_extended_header(args);
-	if (!err)
-		err = write_archive_entries(args, write_tar_entry);
+	write_global_extended_header(args);
+	err = write_archive_entries(args, write_tar_entry);
 	if (!err)
 		write_trailer();
 	return err;