Properly remove leading slash letters and Windows drive letters in cpio.

1 files changed, 45 insertions, 5 deletions

diff --git a/cpio/cpio.c b/cpio/cpio.c
index 57f4e260..627e9c01 100644
--- a/cpio/cpio.c
+++ b/cpio/cpio.c
@@ -118,6 +118,7 @@ static void	mode_in(struct cpio *);
 static void	mode_list(struct cpio *);
 static void	mode_out(struct cpio *);
 static void	mode_pass(struct cpio *, const char *);
+static const char *remove_leading_slash(const char *);
 static int	restore_time(struct cpio *, struct archive_entry *,
 		    const char *, int fd);
 static void	usage(void);
@@ -587,6 +588,49 @@ mode_out(struct cpio *cpio)
 	archive_write_free(cpio->archive);
 }
 
+static const char *
+remove_leading_slash(const char *p)
+{
+	const char *rp;
+
+	/* Remove leading "//./" or "//?/" or "//?/UNC/"
+	 * (absolute path prefixes used by Windows API) */
+	if ((p[0] == '/' || p[0] == '\\') &&
+	    (p[1] == '/' || p[1] == '\\') &&
+	    (p[2] == '.' || p[2] == '?') &&
+	    (p[3] == '/' || p[3] == '\\'))
+	{
+		if (p[2] == '?' &&
+		    (p[4] == 'U' || p[4] == 'u') &&
+		    (p[5] == 'N' || p[5] == 'n') &&
+		    (p[6] == 'C' || p[6] == 'c') &&
+		    (p[7] == '/' || p[7] == '\\'))
+			p += 8;
+		else
+			p += 4;
+	}
+	do {
+		rp = p;
+		/* Remove leading drive letter from archives created
+		 * on Windows. */
+		if (((p[0] >= 'a' && p[0] <= 'z') ||
+		     (p[0] >= 'A' && p[0] <= 'Z')) &&
+			 p[1] == ':') {
+			p += 2;
+		}
+		/* Remove leading "/../", "//", etc. */
+		while (p[0] == '/' || p[0] == '\\') {
+			if (p[1] == '.' && p[2] == '.' &&
+				(p[3] == '/' || p[3] == '\\')) {
+				p += 3; /* Remove "/..", leave "/"
+					 * for next pass. */
+			} else
+				p += 1; /* Remove "/". */
+		}
+	} while (rp != p);
+	return (p);
+}
+
 /*
  * This is used by both out mode (to copy objects from disk into
  * an archive) and pass mode (to copy objects from disk to
@@ -598,7 +642,6 @@ file_to_archive(struct cpio *cpio, const char *srcpath)
 	const char *destpath;
 	struct archive_entry *entry, *spare;
 	size_t len;
-	const char *p;
 	int r;
 
 	/*
@@ -652,10 +695,7 @@ file_to_archive(struct cpio *cpio, const char *srcpath)
 				    "Can't allocate path buffer");
 		}
 		strcpy(cpio->pass_destpath, cpio->destdir);
-		p = srcpath;
-		while (p[0] == '/')
-			++p;
-		strcat(cpio->pass_destpath, p);
+		strcat(cpio->pass_destpath, remove_leading_slash(srcpath));
 		destpath = cpio->pass_destpath;
 	}
 	if (cpio->option_rename)