From ac7b0dbd5a18d2c57a942ca14ac856b8047425ff Mon Sep 17 00:00:00 2001

From: Panu Matilainen <pmatilai@redhat.com>

Date: Tue, 15 Feb 2022 10:43:13 +0200

Subject: [PATCH] Pass file descriptor to file prepare plugin hook, use when

 possible

Sadly the thing that allegedly makes things better mostly just makes

things more complicated as symlinks can't be opened, so we'll now have

to deal with both cases in plugins too. To make matters worse, most

APIs out there support either an fd or a path, but very few support

the *at() style dirfd + basename approach so plugins are stuck with

absolute paths for now.

This is of course a plugin API/ABI change too.

---

 lib/rpmplugin.h   |  2 +-

 lib/rpmplugins.c  |  4 ++--

 lib/rpmplugins.h  |  3 ++-

 plugins/ima.c     |  9 +++++++--

 plugins/selinux.c | 13 ++++++++-----

 5 files changed, 20 insertions(+), 11 deletions(-)

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

index fd81aec8d..fab4b3e83 100644

--- a/lib/rpmplugin.h

+++ b/lib/rpmplugin.h

@@ -57,7 +57,7 @@ typedef rpmRC (*plugin_fsm_file_post_func)(rpmPlugin plugin, rpmfi fi,

 					   const char* path, mode_t file_mode,

 					   rpmFsmOp op, int res);

 typedef rpmRC (*plugin_fsm_file_prepare_func)(rpmPlugin plugin, rpmfi fi,

-					      const char* path,

+					      int fd, const char* path,

 					      const char *dest,

 					      mode_t file_mode, rpmFsmOp op);

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

index 65e684e84..923084b78 100644

--- a/lib/rpmplugins.c

+++ b/lib/rpmplugins.c

@@ -384,7 +384,7 @@ rpmRC rpmpluginsCallFsmFilePost(rpmPlugins plugins, rpmfi fi, const char *path,

 }

 rpmRC rpmpluginsCallFsmFilePrepare(rpmPlugins plugins, rpmfi fi,

-				   const char *path, const char *dest,

+				   int fd, const char *path, const char *dest,

 				   mode_t file_mode, rpmFsmOp op)

 {

     plugin_fsm_file_prepare_func hookFunc;

@@ -394,7 +394,7 @@ rpmRC rpmpluginsCallFsmFilePrepare(rpmPlugins plugins, rpmfi fi,

     for (i = 0; i < plugins->count; i++) {

 	rpmPlugin plugin = plugins->plugins[i];

 	RPMPLUGINS_SET_HOOK_FUNC(fsm_file_prepare);

-	if (hookFunc && hookFunc(plugin, fi, path, dest, file_mode, op) == RPMRC_FAIL) {

+	if (hookFunc && hookFunc(plugin, fi, fd, path, dest, file_mode, op) == RPMRC_FAIL) {

 	    rpmlog(RPMLOG_ERR, "Plugin %s: hook fsm_file_prepare failed\n", plugin->name);

 	    rc = RPMRC_FAIL;

 	}

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

index 39762c376..ddf5d7048 100644

--- a/lib/rpmplugins.h

+++ b/lib/rpmplugins.h

@@ -156,6 +156,7 @@ rpmRC rpmpluginsCallFsmFilePost(rpmPlugins plugins, rpmfi fi, const char* path,

  * permissions etc, but before committing file to destination path.

  * @param plugins	plugins structure

  * @param fi		file info iterator (or NULL)

+ * @param fd		file descriptor (or -1 if not available)

  * @param path		file object current path

  * @param dest		file object destination path

  * @param mode		file object mode

@@ -164,7 +165,7 @@ rpmRC rpmpluginsCallFsmFilePost(rpmPlugins plugins, rpmfi fi, const char* path,

  */

 RPM_GNUC_INTERNAL

 rpmRC rpmpluginsCallFsmFilePrepare(rpmPlugins plugins, rpmfi fi,

-                                   const char *path, const char *dest,

+                                   int fd, const char *path, const char *dest,

                                    mode_t mode, rpmFsmOp op);

 #ifdef __cplusplus

diff --git a/plugins/ima.c b/plugins/ima.c

index fe6d3ad7f..9c28a41a3 100644

--- a/plugins/ima.c

+++ b/plugins/ima.c

@@ -39,7 +39,7 @@ static int check_zero_hdr(const unsigned char *fsig, size_t siglen)

 	return (memcmp(fsig, &zero_hdr, sizeof(zero_hdr)) == 0);

 }

-static rpmRC ima_fsm_file_prepare(rpmPlugin plugin, rpmfi fi,

+static rpmRC ima_fsm_file_prepare(rpmPlugin plugin, rpmfi fi, int fd,

                                   const char *path,

                                   const char *dest,

                                   mode_t file_mode, rpmFsmOp op)

@@ -68,8 +68,13 @@

 	fsig = rpmfiFSignature(fi, &len;;

 	if (fsig && (check_zero_hdr(fsig, len) == 0)) {

-	    if (lsetxattr(path, XATTR_NAME_IMA, fsig, len, 0) < 0) {

-		int is_err = errno != EOPNOTSUPP; 

+	    int xx;

+	    if (fd >= 0)

+		xx = fsetxattr(fd, XATTR_NAME_IMA, fsig, len, 0);

+	    else

+		xx = lsetxattr(path, XATTR_NAME_IMA, fsig, len, 0);

+	    if (xx < 0) {

+		int is_err = errno != EOPNOTSUPP;

 	        rpmlog(is_err?RPMLOG_ERR:RPMLOG_DEBUG,

 			"ima: could not apply signature on '%s': %s\n",

 			path, strerror(errno));

diff --git a/plugins/fapolicyd.c b/plugins/fapolicyd.c

index 7ac44f0d0..1ff50c30f 100644

--- a/plugins/fapolicyd.c

+++ b/plugins/fapolicyd.c

@@ -145,7 +145,8 @@ static rpmRC fapolicyd_scriptlet_pre(rpmPlugin plugin, const char *s_name,

 }

 static rpmRC fapolicyd_fsm_file_prepare(rpmPlugin plugin, rpmfi fi,

-                                        const char *path, const char *dest,

+                                        int fd, const char *path,

+					const char *dest,

                                         mode_t file_mode, rpmFsmOp op)

 {

     /* not ready  */

diff --git a/plugins/selinux.c b/plugins/selinux.c

index 32c3b7529..a7f20aeca 100644

--- a/plugins/selinux.c

+++ b/plugins/selinux.c

@@ -149,7 +149,7 @@ static rpmRC selinux_scriptlet_fork_post(rpmPlugin plugin,

     return rc;

 }

-static rpmRC selinux_fsm_file_prepare(rpmPlugin plugin, rpmfi fi,

+static rpmRC selinux_fsm_file_prepare(rpmPlugin plugin, rpmfi fi, int fd,

 					const char *path, const char *dest,

 				        mode_t file_mode, rpmFsmOp op)

 {

@@ -194,13 +194,17 @@

     if (sehandle && !XFA_SKIPPING(action)) {

 	char *scon = NULL;

 	if (selabel_lookup_raw(sehandle, &scon, dest, file_mode) == 0) {

-	    int conrc = lsetfilecon(path, scon);

+	    int conrc;

+	    if (fd >= 0)

+		conrc = fsetfilecon(fd, scon);

+	    else

+		conrc = lsetfilecon(path, scon);

 	    if (conrc == 0 || (conrc < 0 && errno == EOPNOTSUPP))

 		rc = RPMRC_OK;

-	    rpmlog(loglvl(rc != RPMRC_OK), "lsetfilecon: (%s, %s) %s\n",

-		       path, scon, (conrc < 0 ? strerror(errno) : ""));

+	    rpmlog(loglvl(rc != RPMRC_OK), "lsetfilecon: (%d %s, %s) %s\n",

+		   fd, path, scon, (conrc < 0 ? strerror(errno) : ""));

 	    freecon(scon);

 	} else {

-- 

2.41.0