2009-04-29 21:56:41

by Kevin Coffman

[permalink] [raw]
Subject: [PATCH 6/7] gssd: process target= attribute in new upcall

From: Olga Kornievskaia <[email protected]>

Add processing of the "target=" attribute in the new gssd upcall.
Information in this field is used to construct the gss service name
of the server for which gssd will create a context .

This, along with the next patch handling "service=", is needed
for callback security.

For Kerberos, the NFS client will use a service principal present
in its keytab during authentication of the SETCLIENT_ID operation.
When establishing the context for the callback, the gssd on the
NFS server will attempt to authenticate the callback against the
principal name used by the client.

Note: An NFS client machine must have a keytab for the callback
authentication to succeed.

Signed-off-by: Olga Kornievskaia <[email protected]>
Signed-off-by: Kevin Coffman <[email protected]>
---

utils/gssd/gssd_proc.c | 26 +++++++++++++++++++++++---
1 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index 2fc26b4..12eb5b3 100644
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -885,7 +885,7 @@ int create_auth_rpc_client(struct clnt_info *clp,
* context on behalf of the kernel
*/
static void
-process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd)
+process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd, char *tgtname)
{
CLIENT *rpc_clnt = NULL;
AUTH *auth = NULL;
@@ -898,6 +898,12 @@ process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd)

printerr(1, "handling krb5 upcall (%s)\n", clp->dirname);

+ if (tgtname) {
+ if (clp->servicename) {
+ free(clp->servicename);
+ clp->servicename = strdup(tgtname);
+ }
+ }
token.length = 0;
token.value = NULL;
memset(&pd, 0, sizeof(struct authgss_private_data));
@@ -1056,7 +1062,7 @@ handle_krb5_upcall(struct clnt_info *clp)
return;
}

- return process_krb5_upcall(clp, uid, clp->krb5_fd);
+ return process_krb5_upcall(clp, uid, clp->krb5_fd, NULL);
}

void
@@ -1081,6 +1087,7 @@ handle_gssd_upcall(struct clnt_info *clp)
int lbuflen = 0;
char *p;
char *mech = NULL;
+ char *target = NULL;

printerr(1, "handling gssd upcall (%s)\n", clp->dirname);

@@ -1124,9 +1131,21 @@ handle_gssd_upcall(struct clnt_info *clp)
goto out;
}

+ /* read target name */
+ if ((p = strstr(lbuf, "target=")) != NULL) {
+ target = malloc(lbuflen);
+ if (!target)
+ goto out;
+ if (sscanf(p, "target=%s", target) != 1) {
+ printerr(0, "WARNING: handle_gssd_upcall: "
+ "failed to parse target name "
+ "in upcall string '%s'\n", lbuf);
+ goto out;
+ }
+ }

if (strcmp(mech, "krb5") == 0)
- process_krb5_upcall(clp, uid, clp->gssd_fd);
+ process_krb5_upcall(clp, uid, clp->gssd_fd, target);
else if (strcmp(mech, "spkm3") == 0)
process_spkm3_upcall(clp, uid, clp->gssd_fd);
else
@@ -1136,6 +1155,7 @@ handle_gssd_upcall(struct clnt_info *clp)
out:
free(lbuf);
free(mech);
+ free(target);
return;
}