2008-04-08 18:33:31

by Kevin Coffman

[permalink] [raw]
Subject: [PATCH 2/2] gssd: search multiple directories for Kerberos credentials

From: Kevin Coffman <[email protected]>

Kerberos credentials may be stored in multiple places. Make it
possible to search several directories for valid credentials when
making NFS requests.

Original patch from Vince Busam <[email protected]>, modified by
Kevin Coffman <[email protected]>.

Signed-off-by: Vince Busam <[email protected]>
Signed-off-by: Kevin Coffman <[email protected]>
---

utils/gssd/gssd.c | 10 ++++++++++
utils/gssd/gssd.h | 3 ++-
utils/gssd/gssd.man | 6 +++++-
utils/gssd/gssd_proc.c | 11 ++++++++---
utils/gssd/krb5_util.c | 30 ++++++++++++++++--------------
utils/gssd/krb5_util.h | 3 ++-
6 files changed, 43 insertions(+), 20 deletions(-)


diff --git a/utils/gssd/gssd.c b/utils/gssd/gssd.c
index bbcad20..e8612a5 100644
--- a/utils/gssd/gssd.c
+++ b/utils/gssd/gssd.c
@@ -57,6 +57,7 @@ char pipefs_dir[PATH_MAX] = GSSD_PIPEFS_DIR;
char pipefs_nfsdir[PATH_MAX] = GSSD_PIPEFS_DIR;
char keytabfile[PATH_MAX] = GSSD_DEFAULT_KEYTAB_FILE;
char ccachedir[PATH_MAX] = GSSD_DEFAULT_CRED_DIR;
+char *ccachesearch[GSSD_MAX_CCACHE_SEARCH + 1];
int use_memcache = 0;
int root_uses_machine_creds = 1;

@@ -93,9 +94,11 @@ main(int argc, char *argv[])
int verbosity = 0;
int rpc_verbosity = 0;
int opt;
+ int i;
extern char *optarg;
char *progname;

+ memset(ccachesearch, 0, sizeof(ccachesearch));
while ((opt = getopt(argc, argv, "fvrmnMp:k:d:")) != -1) {
switch (opt) {
case 'f':
@@ -136,6 +139,13 @@ main(int argc, char *argv[])
break;
}
}
+
+ i = 0;
+ ccachesearch[i++] = strtok(ccachedir, ":");
+ do {
+ ccachesearch[i++] = strtok(NULL, ":");
+ } while (ccachesearch[i-1] != NULL && i < GSSD_MAX_CCACHE_SEARCH);
+
snprintf(pipefs_nfsdir, sizeof(pipefs_nfsdir), "%s/%s",
pipefs_dir, GSSD_SERVICE_NAME);
if (pipefs_nfsdir[sizeof(pipefs_nfsdir)-1] != '\0')
diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
index e17edde..9e1ab43 100644
--- a/utils/gssd/gssd.h
+++ b/utils/gssd/gssd.h
@@ -50,6 +50,7 @@
#define GSSD_DEFAULT_KEYTAB_FILE "/etc/krb5.keytab"
#define GSSD_SERVICE_NAME "nfs"
#define GSSD_SERVICE_NAME_LEN 3
+#define GSSD_MAX_CCACHE_SEARCH 16

/*
* The gss mechanisms that we can handle
@@ -61,7 +62,7 @@ enum {AUTHTYPE_KRB5, AUTHTYPE_SPKM3, AUTHTYPE_LIPKEY};
extern char pipefs_dir[PATH_MAX];
extern char pipefs_nfsdir[PATH_MAX];
extern char keytabfile[PATH_MAX];
-extern char ccachedir[PATH_MAX];
+extern char *ccachesearch[];
extern int use_memcache;
extern int root_uses_machine_creds;

diff --git a/utils/gssd/gssd.man b/utils/gssd/gssd.man
index 2fa749e..8fa4f4a 100644
--- a/utils/gssd/gssd.man
+++ b/utils/gssd/gssd.man
@@ -74,7 +74,11 @@ 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".
+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
+stored in files, then the first directory on this list is where the
+machine credentials are stored.
.TP
.B -v
Increases the verbosity of the output (can be specified multiple times).
diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index 6860cc8..17f85e1 100644
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -675,6 +675,7 @@ handle_krb5_upcall(struct clnt_info *clp)
gss_buffer_desc token;
char **credlist = NULL;
char **ccname;
+ char **dirname;
int create_resp = -1;

printerr(1, "handling krb5 upcall\n");
@@ -691,10 +692,14 @@ handle_krb5_upcall(struct clnt_info *clp)

if (uid != 0 || (uid == 0 && root_uses_machine_creds == 0)) {
/* Tell krb5 gss which credentials cache to use */
- gssd_setup_krb5_user_gss_ccache(uid, clp->servername);
+ for (dirname = ccachesearch; *dirname != NULL; dirname++) {
+ gssd_setup_krb5_user_gss_ccache(uid, clp->servername, *dirname);

- create_resp = create_auth_rpc_client(clp, &rpc_clnt, &auth, uid,
- AUTHTYPE_KRB5);
+ create_resp = create_auth_rpc_client(clp, &rpc_clnt, &auth, uid,
+ AUTHTYPE_KRB5);
+ if (create_resp == 0)
+ break;
+ }
}
if (create_resp != 0) {
if (uid == 0 && root_uses_machine_creds == 1) {
diff --git a/utils/gssd/krb5_util.c b/utils/gssd/krb5_util.c
index 0589cd8..512c1cf 100644
--- a/utils/gssd/krb5_util.c
+++ b/utils/gssd/krb5_util.c
@@ -131,7 +131,8 @@ struct gssd_k5_kt_princ *gssd_k5_kt_princ_list = NULL;
/*==========================*/

static int select_krb5_ccache(const struct dirent *d);
-static int gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d);
+static int gssd_find_existing_krb5_ccache(uid_t uid, char *dirname,
+ struct dirent **d);
static int gssd_get_single_krb5_cred(krb5_context context,
krb5_keytab kt, struct gssd_k5_kt_princ *ple);

@@ -159,7 +160,7 @@ select_krb5_ccache(const struct dirent *d)
}

/*
- * Look in the ccachedir for files that look like they
+ * Look in directory "dirname" for files that look like they
* are Kerberos Credential Cache files for a given UID. Return
* non-zero and the dirent pointer for the entry most likely to be
* what we want. Otherwise, return zero and no dirent pointer.
@@ -170,7 +171,7 @@ select_krb5_ccache(const struct dirent *d)
* 1 => found an existing entry
*/
static int
-gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d)
+gssd_find_existing_krb5_ccache(uid_t uid, char *dirname, struct dirent **d)
{
struct dirent **namelist;
int n;
@@ -181,9 +182,10 @@ gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d)

memset(&best_match_stat, 0, sizeof(best_match_stat));
*d = NULL;
- n = scandir(ccachedir, &namelist, select_krb5_ccache, 0);
+ n = scandir(dirname, &namelist, select_krb5_ccache, 0);
if (n < 0) {
- perror("scandir looking for krb5 credentials caches");
+ printerr(1, "Error doing scandir on directory '%s': %s\n",
+ dirname, strerror(errno));
}
else if (n > 0) {
char statname[1024];
@@ -191,7 +193,7 @@ gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d)
printerr(3, "CC file '%s' being considered\n",
namelist[i]->d_name);
snprintf(statname, sizeof(statname),
- "%s/%s", ccachedir, namelist[i]->d_name);
+ "%s/%s", dirname, namelist[i]->d_name);
if (lstat(statname, &tmp_stat)) {
printerr(0, "Error doing stat on file '%s'\n",
statname);
@@ -291,8 +293,9 @@ limit_krb5_enctypes(struct rpc_gss_sec *sec, uid_t uid)
&credh, NULL, NULL);

if (maj_stat != GSS_S_COMPLETE) {
- pgsserr("gss_acquire_cred",
- maj_stat, min_stat, &krb5oid);
+ if (get_verbosity() > 0)
+ pgsserr("gss_acquire_cred",
+ maj_stat, min_stat, &krb5oid);
return -1;
}

@@ -406,7 +409,7 @@ gssd_get_single_krb5_cred(krb5_context context,
cache_type = "FILE";
snprintf(cc_name, sizeof(cc_name), "%s:%s/%s%s_%s",
cache_type,
- ccachedir, GSSD_DEFAULT_CRED_PREFIX,
+ ccachesearch[0], GSSD_DEFAULT_CRED_PREFIX,
GSSD_DEFAULT_MACHINE_CRED_SUFFIX, ple->realm);
ple->endtime = my_creds.times.endtime;
if (ple->ccname != NULL)
@@ -894,7 +897,7 @@ out:
* void
*/
void
-gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername)
+gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername, char *dirname)
{
char buf[MAX_NETOBJ_SZ];
struct dirent *d;
@@ -902,14 +905,13 @@ gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername)
printerr(2, "getting credentials for client with uid %u for "
"server %s\n", uid, servername);
memset(buf, 0, sizeof(buf));
- if (gssd_find_existing_krb5_ccache(uid, &d)) {
- snprintf(buf, sizeof(buf), "FILE:%s/%s",
- ccachedir, d->d_name);
+ if (gssd_find_existing_krb5_ccache(uid, dirname, &d)) {
+ snprintf(buf, sizeof(buf), "FILE:%s/%s", dirname, d->d_name);
free(d);
}
else
snprintf(buf, sizeof(buf), "FILE:%s/%s%u",
- ccachedir, GSSD_DEFAULT_CRED_PREFIX, uid);
+ dirname, GSSD_DEFAULT_CRED_PREFIX, uid);
printerr(2, "using %s as credentials cache for client with "
"uid %u for server %s\n", buf, uid, servername);
gssd_set_krb5_ccache_name(buf);
diff --git a/utils/gssd/krb5_util.h b/utils/gssd/krb5_util.h
index 78ad45c..431fdaf 100644
--- a/utils/gssd/krb5_util.h
+++ b/utils/gssd/krb5_util.h
@@ -17,7 +17,8 @@ struct gssd_k5_kt_princ {
};


-void gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername);
+void gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername,
+ char *dirname);
int gssd_get_krb5_machine_cred_list(char ***list);
void gssd_free_krb5_machine_cred_list(char **list);
void gssd_setup_krb5_machine_gss_ccache(char *servername);