[PATCH 5/6] src/fssum: Allow single file input

[Arvind Raghavan <raghavan.arvind@gmail.com>]

Allow regular links and symlinks to be passed as input to fssum.

Signed-off-by: Arvind Raghavan <raghavan.arvind@gmail.com>
Signed-off-by: Jayashree Mohan <jaya@cs.utexas.edu>
Signed-off-by: Vijay Chidambaram <vijay@cs.utexas.edu>
---
 src/fssum.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/fssum.c b/src/fssum.c
index ece0f556..2d1624ca 100644
--- a/src/fssum.c
+++ b/src/fssum.c
@@ -29,6 +29,7 @@
 #include <inttypes.h>
 #include <assert.h>
 #include <endian.h>
+#include <libgen.h>
 
 #define CS_SIZE 16
 #define CHUNKS	128
@@ -884,8 +885,40 @@ main(int argc, char *argv[])
 	if (gen_manifest)
 		fprintf(out_fp, "Flags: %s\n", flagstring);
 
+	struct stat64 path_st;
+	if (fstat64(fd, &path_st)) {
+		perror("fstat");
+		exit(-1);
+	}
+
 	sum_init(&cs);
-	sum(fd, 1, &cs, path, "");
+
+	if (S_ISDIR(path_st.st_mode)) {
+		sum(fd, 1, &cs, path, "");
+	} else if (S_ISREG(path_st.st_mode) || S_ISLNK(path_st.st_mode)) {
+		// Copy because dirname may modify path
+		char* path_copy = alloc(strlen(path));
+		strcpy(path_copy, path);
+
+		char* dir_path = dirname(path);
+		char* name = basename(path_copy);
+
+		int dirfd = open(dir_path, O_RDONLY);
+		if (fd == -1) {
+			fprintf(stderr, "failed to open %s: %s\n", dir_path,
+				strerror(errno));
+			exit(-1);
+		}
+
+		sum_one(dirfd, 1, &cs, dir_path, "", name);
+
+		free(path_copy);
+		close(dirfd);
+	} else {
+		fprintf(stderr, "path must be file or dir: %s", path);
+		exit(-1);
+	}
+
 	sum_fini(&cs);
 
 	close(fd);
-- 
2.20.1