---
I wouldn't bother with the Error enum, since after you assign the errnum, you
immediately look it up in the error table. Instead, you can just set the reason
string directly. I also think it's worth differentiating between an invalid and
incorrect checksum.
Here is the patch I mentioned in my previous reply.
tar.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/tar.c b/tar.c
index 2272303..44353d7 100644
--- a/tar.c
+++ b/tar.c
@@ -408,30 +408,38 @@ sanitize(struct header *h)
static void
chktar(struct header *h)
{
- char tmp[8], *err;
- char *p = (char *)h;
+ char tmp[8], *err, *p = (char *)h;
+ const char *reason;
long s1, s2, i;
- if (h->prefix[0] == '\0' && h->name[0] == '\0')
+ if (h->prefix[0] == '\0' && h->name[0] == '\0') {
+ reason = "empty filename";
goto bad;
- if (h->magic[0] && strncmp("ustar", h->magic, 5))
+ }
+ if (h->magic[0] && strncmp("ustar", h->magic, 5)) {
+ reason = "not ustar format";
goto bad;
+ }
memcpy(tmp, h->chksum, sizeof(tmp));
for (i = 0; i < sizeof(tmp); i++)
if (tmp[i] == ' ')
tmp[i] = '\0';
s1 = strtol(tmp, &err, 8);
- if (s1 < 0 || *err != '\0')
+ if (s1 < 0 || *err != '\0') {
+ reason = "invalid checksum";
goto bad;
+ }
memset(h->chksum, ' ', sizeof(h->chksum));
for (i = 0, s2 = 0; i < sizeof(*h); i++)
s2 += (unsigned char)p[i];
- if (s1 != s2)
+ if (s1 != s2) {
+ reason = "incorrect checksum";
goto bad;
+ }
memcpy(h->chksum, tmp, sizeof(h->chksum));
return;
bad:
- eprintf("malformed tar archive\n");
+ eprintf("malformed tar archive: %s\n", reason);
}
static void
--
2.11.0
