Re: [Libguestfs] [PATCH] lib: update inspect_list_applications to return all installed RPMs (RHBZ#859885)
On Mon, Oct 29, 2012 at 12:45:17PM -0400, John Eckersberg wrote:
Note that because of RHBZ#859949, this will return two identical
entries for RPMs which differ only by arch.
I get a lot of warnings (== errors) because I'm using
./configure --enable-gcc-warnings, so I wasn't able to compile
this patch. These need to be fixed first.
+/* tag constants, see rpmtag.h in RPM for complete list */
+#define RPMTAG_VERSION 1001
+#define RPMTAG_RELEASE 1002
+#define RPMTAG_ARCH 1022
Keep the definition of RPMTAG_ARCH out of this patch, for the later
arch patch. (This is one of the GCC warnings too).
+
+static char *
+get_rpm_header_tag (guestfs_h *g, const void *header_start, size_t header_len, uint32_t
tag)
+{
+ uint32_t num_fields, offset;
+ const void *cursor = header_start + 8, *store;
+
+ /* This function parses the RPM header structure to pull out various
+ * tag strings (version, release, arch, etc.). For more detail on the
+ * header format, see:
+ *
http://www.rpm.org/max-rpm/s1-rpm-file-format-rpm-file-format.html#S2-RPM...
+ */
+
+ num_fields = be32toh (*(uint32_t *) header_start);
+ store = header_start + 8 + (16 * num_fields);
+
+ while (cursor < store && cursor < header_start + header_len) {
+ if (be32toh (*(uint32_t *) cursor) == tag){
^ Space before '{' character.
+ offset = be32toh(*(uint32_t *) (cursor + 8));
+ return safe_strdup(g, store + offset);
+ }
+ cursor += 16;
+ }
I'm curious if this code will work if header_len is unusually small.
I think it would cause the library to read past the end of the
allocated buffer, possibly crashing or doing other Bad Stuff. Note
that the header_len field is under control of the guest, so this could
be a security problem.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages. http://libguestfs.org