[PATCH 2/2] Use /run/user/${UID} instead of /run/user/${USER}

[Nalin Dahyabhai <nalin@redhat.com>]

Newer versions of systemd create a /run/user/${UID} directory
instead of the /run/user/${USER} directory, so switch to
scanning for that.  To make the per-user directory bit a little
less magical, change the default to incorporate a "%U", which
gets dynamically expanded to the user's UID when needed.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
---
 utils/gssd/gssd.h      |  2 +-
 utils/gssd/gssd.man    |  9 ++++++---
 utils/gssd/gssd_proc.c | 36 ++----------------------------------
 utils/gssd/krb5_util.c | 30 ++++++++++++++++++++++++++----
 4 files changed, 35 insertions(+), 42 deletions(-)

diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
index 1d923d7..86472a1 100644
--- a/utils/gssd/gssd.h
+++ b/utils/gssd/gssd.h
@@ -45,7 +45,7 @@
 #define DNOTIFY_SIGNAL		(SIGRTMIN + 3)
 
 #define GSSD_DEFAULT_CRED_DIR			"/tmp"
-#define GSSD_USER_CRED_DIR			"/run/user"
+#define GSSD_USER_CRED_DIR			"/run/user/%U"
 #define GSSD_DEFAULT_CRED_PREFIX		"krb5cc"
 #define GSSD_DEFAULT_MACHINE_CRED_SUFFIX	"machine"
 #define GSSD_DEFAULT_KEYTAB_FILE		"/etc/krb5.keytab"
diff --git a/utils/gssd/gssd.man b/utils/gssd/gssd.man
index d8138fa..c74b7e8 100644
--- a/utils/gssd/gssd.man
+++ b/utils/gssd/gssd.man
@@ -103,9 +103,12 @@ where to look for the rpc_pipefs filesystem.  The default value is
 .B -d directory
 Tells
 .B rpc.gssd
-where to look for Kerberos credential files.  The default value is "/tmp".
-This can also be a colon separated list of directories to be searched
-for Kerberos credential files.  Note that if machine credentials are being
+where to look for Kerberos credential files.  The default value is
+"/tmp:/run/user/%U".
+This can also be a colon separated list of directories to be searched for
+Kerberos credential files.  The sequence "%U", if used, is replaced with
+the UID of the user for whom credentials are being searched.
+Note that if machine credentials are being
 stored in files, then the first directory on this list is where the
 machine credentials are stored.
 .TP
diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index e393d59..336f3e9 100644
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -937,23 +937,6 @@ int create_auth_rpc_client(struct clnt_info *clp,
 	goto out;
 }
 
-static char *
-user_cachedir(char *dirname, uid_t uid)
-{
-	struct passwd *pw;
-	char *ptr;
-
-	if ((pw = getpwuid(uid)) == NULL) {
-		printerr(0, "user_cachedir: Failed to find '%d' uid"
-			    " for cache directory\n");
-		return NULL;
-	}
-	ptr = malloc(strlen(dirname)+strlen(pw->pw_name)+2);
-	if (ptr)
-		sprintf(ptr, "%s/%s", dirname, pw->pw_name);
-
-	return ptr;
-}
 /*
  * this code uses the userland rpcsec gss library to create a krb5
  * context on behalf of the kernel
@@ -968,7 +951,7 @@ process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd, char *tgtname,
 	gss_buffer_desc		token;
 	char			**credlist = NULL;
 	char			**ccname;
-	char			**dirname, *dir, *userdir;
+	char			**dirname;
 	int			create_resp = -1;
 	int			err, downcall_err = -EACCES;
 
@@ -1011,22 +994,7 @@ process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd, char *tgtname,
 				service == NULL)) {
 		/* Tell krb5 gss which credentials cache to use */
 		for (dirname = ccachesearch; *dirname != NULL; dirname++) {
-			/* See if the user name is needed */
-			if (strncmp(*dirname, GSSD_USER_CRED_DIR, 
-					strlen(GSSD_USER_CRED_DIR)) == 0) {
-				userdir = user_cachedir(*dirname, uid);
-				if (userdir == NULL) 
-					continue;
-				dir = userdir;
-			} else
-				dir = *dirname;
-
-			err = gssd_setup_krb5_user_gss_ccache(uid, clp->servername, dir);
-
-			if (userdir) {
-				free(userdir);
-				userdir = NULL;
-			}
+			err = gssd_setup_krb5_user_gss_ccache(uid, clp->servername, *dirname);
 			if (err == -EKEYEXPIRED)
 				downcall_err = -EKEYEXPIRED;
 			else if (!err)
diff --git a/utils/gssd/krb5_util.c b/utils/gssd/krb5_util.c
index 2389276..60ba594 100644
--- a/utils/gssd/krb5_util.c
+++ b/utils/gssd/krb5_util.c
@@ -1036,16 +1036,38 @@ err_cache:
  * Returns 0 if a ccache was found, and a non-zero error code otherwise.
  */
 int
-gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername, char *dirname)
+gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername, char *dirpattern)
 {
-	char			buf[MAX_NETOBJ_SZ];
+	char			buf[MAX_NETOBJ_SZ], dirname[PATH_MAX];
 	const char		*cctype;
 	struct dirent		*d;
-	int			err;
+	int			err, i, j;
 
 	printerr(2, "getting credentials for client with uid %u for "
 		    "server %s\n", uid, servername);
-	memset(buf, 0, sizeof(buf));
+
+	for (i = 0, j = 0; dirpattern[i] != '\0'; i++) {
+		switch (dirpattern[i]) {
+		case '%':
+			switch (dirpattern[i + 1]) {
+			case '%':
+				dirname[j++] = dirpattern[i];
+				i++;
+				break;
+			case 'U':
+				j += sprintf(dirname + j, "%lu",
+					     (unsigned long) uid);
+				i++;
+				break;
+			}
+			break;
+		default:
+			dirname[j++] = dirpattern[i];
+			break;
+		}
+	}
+	dirname[j] = '\0';
+
 	err = gssd_find_existing_krb5_ccache(uid, dirname, &cctype, &d);
 	if (err)
 		return err;
-- 
1.7.11.5