From aabaa6c6587c37b84a1b9cfd98bff31f1b69345e Mon Sep 17 00:00:00 2001

From: chantra <chantr4@gmail.com>

Date: Wed, 16 Feb 2022 17:00:09 -0800

Subject: [PATCH 24/30] [rpm2extents] create footer struct and helpers

new extents_footer and extents_footer_offset struct with a function to

load offsets from an FD.

Change existing code to use new struct/functions

---

 lib/rpmchecksig.c         | 16 +++-------------

 lib/rpmextents.c          | 26 +++++++++++++++++---------

 lib/rpmextents_internal.h | 31 ++++++++++++++++++++++++++++++-

 rpm2extents.c             | 23 ++++-------------------

 4 files changed, 54 insertions(+), 42 deletions(-)

diff --git a/lib/rpmchecksig.c b/lib/rpmchecksig.c

index dc1726a18..729f79f9f 100644

--- a/lib/rpmchecksig.c

+++ b/lib/rpmchecksig.c

@@ -223,29 +223,19 @@ exit:

 static int rpmpkgVerifySigsTranscoded(FD_t fd){

     rpm_loff_t current;

-    uint64_t magic;

-    rpm_loff_t offset;

     int32_t rc;

     size_t len;

     uint64_t content_len;

     char *content = NULL;

+    struct extents_footer_t footer;

     current = Ftell(fd);

-    if(Fseek(fd, -(sizeof(magic) + 3 * sizeof(offset) ), SEEK_END) < 0) {

-	rpmlog(RPMLOG_ERR, _("rpmpkgVerifySigsTranscoded: failed to seek for offset\n"));

+    if(extentsFooterFromFD(fd, &footer) != RPMRC_OK) {

 	rc = -1;

 	goto exit;

     }

-

-    len = sizeof(offset);

-    if (Fread(&offset, len, 1, fd) != len) {

-	rpmlog(RPMLOG_ERR, _("rpmpkgVerifySigsTranscoded: Failed to read Signature Verification offset\n"));

-	rc = -1;

-	goto exit;

-    }

-

-    if(Fseek(fd,  offset, SEEK_SET) < 0) {

+    if(Fseek(fd, footer.offsets.checksig_offset, SEEK_SET) < 0) {

 	rpmlog(RPMLOG_ERR, _("rpmpkgVerifySigsTranscoded: Failed to seek signature verification offset\n"));

 	rc = -1;

 	goto exit;

diff --git a/lib/rpmextents.c b/lib/rpmextents.c

index 015277751..46b7aadff 100644

--- a/lib/rpmextents.c

+++ b/lib/rpmextents.c

@@ -3,13 +3,16 @@

 #include <rpm/rpmlog.h>

 #include <rpm/rpmio.h>

+#include <string.h>

+#include <errno.h>

+

 #include "lib/rpmextents_internal.h"

-rpmRC isTranscodedRpm(FD_t fd) {

+rpmRC extentsFooterFromFD(FD_t fd, struct extents_footer_t *footer) {

+

     rpmRC rc = RPMRC_NOTFOUND;

     rpm_loff_t current;

-    extents_magic_t magic;

     size_t len;

     // If the file is not seekable, we cannot detect whether or not it is transcoded.

@@ -18,19 +21,19 @@ rpmRC isTranscodedRpm(FD_t fd) {

     }

     current = Ftell(fd);

-    if(Fseek(fd, -(sizeof(magic)), SEEK_END) < 0) {

-	rpmlog(RPMLOG_ERR, _("isTranscodedRpm: failed to seek for magic\n"));

+    len = sizeof(struct extents_footer_t);

+    if(Fseek(fd, -len, SEEK_END) < 0) {

+	rpmlog(RPMLOG_ERR, _("isTranscodedRpm: failed to seek for footer: %s\n"), strerror(errno));

 	rc = RPMRC_FAIL;

 	goto exit;

     }

-    len = sizeof(magic);

-    if (Fread(&magic, len, 1, fd) != len) {

-	rpmlog(RPMLOG_ERR, _("isTranscodedRpm: unable to read magic\n"));

+    if (Fread(footer, len, 1, fd) != len) {

+	rpmlog(RPMLOG_ERR, _("isTranscodedRpm: unable to read footer\n"));

 	rc = RPMRC_FAIL;

 	goto exit;

     }

-    if (magic != EXTENTS_MAGIC) {

-	rpmlog(RPMLOG_DEBUG, _("isTranscodedRpm: not transcoded\n"));

+    if (footer->magic != EXTENTS_MAGIC) {

+	rpmlog(RPMLOG_ERR, _("isTranscodedRpm: not transcoded\n"));

 	rc = RPMRC_NOTFOUND;

 	goto exit;

     }

@@ -43,4 +46,9 @@ exit:

     return rc;

 }

+rpmRC isTranscodedRpm(FD_t fd) {

+    struct extents_footer_t footer;

+    return extentsFooterFromFD(fd, &footer);

+}

+

diff --git a/lib/rpmextents_internal.h b/lib/rpmextents_internal.h

index 57cecfc31..f0c29c807 100644

--- a/lib/rpmextents_internal.h

+++ b/lib/rpmextents_internal.h

@@ -7,6 +7,10 @@ extern "C" {

 #include <stdint.h>

+/** \ingroup rpmextents

+ * RPM extents library

+ */

+

 /* magic value at end of file (64 bits) that indicates this is a transcoded

  * rpm.

  */

@@ -14,9 +18,34 @@ extern "C" {

 typedef uint64_t extents_magic_t;

+struct __attribute__ ((__packed__)) extents_footer_offsets_t {

+    off64_t checksig_offset;

+    off64_t table_offset;

+    off64_t csum_offset;

+};

+

+struct __attribute__ ((__packed__)) extents_footer_t {

+    struct extents_footer_offsets_t offsets;

+    extents_magic_t magic;

+};

+

+

+/** \ingroup rpmextents

+ * Read the RPM Extents footer from a file descriptor.

+ * @param fd		The FD_t of the transcoded RPM

+ * @param[out] footer	A pointer to an allocated extents_footer_t with a copy of the footer.

+ * @return		RPMRC_OK on success, RPMRC_NOTFOUND if not a transcoded file, RPMRC_FAIL on any failure.

+ */

+rpmRC extentsFooterFromFD(FD_t fd, struct extents_footer_t *footer);

+

+/** \ingroup rpmextents

+ * Check if a RPM is a transcoded RPM

+ * @param fd	The FD_t of the transcoded RPM

+ * return	RPMRC_OK on success, RPMRC_NOTFOUND if not a transcoded file, RPMRC_FAIL on any failure.

+ */

 rpmRC isTranscodedRpm(FD_t fd);

 #ifdef __cplusplus

 }

 #endif

-#endif

+#endif /* _RPMEXTENTS_INTERNAL_H */

diff --git a/rpm2extents.c b/rpm2extents.c

index e1a19fedb..7dd5128de 100644

--- a/rpm2extents.c

+++ b/rpm2extents.c

@@ -405,25 +405,10 @@ static rpmRC process_package(FD_t fdi, FD_t digestori, FD_t validationi)

 	goto exit;

     }

     zeros = _free(zeros);

-    if (Fwrite(&validation_pos, len, 1, fdo) != len) {

-	rpmlog(RPMLOG_ERR, _("Unable to write offset of validation output\n"));

-	rc = RPMRC_FAIL;

-	goto exit;

-    }

-    if (Fwrite(&digest_table_pos, len, 1, fdo) != len) {

-	rpmlog(RPMLOG_ERR, _("Unable to write offset of digest table\n"));

-	rc = RPMRC_FAIL;

-	goto exit;

-    }

-    if (Fwrite(&digest_pos, len, 1, fdo) != len) {

-	rpmlog(RPMLOG_ERR, _("Unable to write offset of validation table\n"));

-	rc = RPMRC_FAIL;

-	goto exit;

-    }

-    extents_magic_t magic = EXTENTS_MAGIC;

-    len = sizeof(magic);

-    if (Fwrite(&magic, len, 1, fdo) != len) {

-	rpmlog(RPMLOG_ERR, _("Unable to write magic\n"));

+    struct extents_footer_t footer = {.offsets = {validation_pos, digest_table_pos, digest_pos}, .magic = EXTENTS_MAGIC};

+    len = sizeof(footer);

+    if (Fwrite(&footer, len, 1, fdo) != len) {

+	rpmlog(RPMLOG_ERR, _("Unable to write footer\n"));

 	rc = RPMRC_FAIL;

 	goto exit;

     }

-- 

2.35.1