gssd: handle new client upcall

Add support for handling the new client-side upcall.  The kernel,
beginning with 2.6.29, will attempt to use a new pipe, "gssd",
which can be used for upcalls for all gss mechanisms.

The new upcall is text-based with an <attribute>=<value> format.
Attribute/value pairs are separated by a space, and terminated
with a new-line character.

The intial version has two required attributes,
mech=<gss_mechanism_name> and uid=<user's_UID_number>, and two
optional attributes, target=<gss_target_name> and service=<value>.

Future kernels may add new attribute/value pairs.

Signed-off-by: Olga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
index 3c53a88dd79bf4072443f4062cc61ecb75f5ec15..465c305f17da92dc06920d77f03ff4986850cfcd 100644 (file)
--- a/utils/gssd/gssd.h
+++ b/utils/gssd/gssd.h
@@ -82,6 +82,8 @@ struct clnt_info {
        int                     krb5_poll_index;
        int                     spkm3_fd;
        int                     spkm3_poll_index;
+       int                     gssd_fd;
+       int                     gssd_poll_index;
        struct sockaddr_storage addr;
 };
 
@@ -97,6 +99,7 @@ void init_client_list(void);
 int update_client_list(void);
 void handle_krb5_upcall(struct clnt_info *clp);
 void handle_spkm3_upcall(struct clnt_info *clp);
+void handle_gssd_upcall(struct clnt_info *clp);
 int gssd_acquire_cred(char *server_name);
 void gssd_run(void);
 

diff --git a/utils/gssd/gssd_main_loop.c b/utils/gssd/gssd_main_loop.c
index b5117c57cc2f3e5f7856d1b42924628bf297cdf6..f1a68d3473550663bd3964aab4bdfe4c53a3e88a 100644 (file)
--- a/utils/gssd/gssd_main_loop.c
+++ b/utils/gssd/gssd_main_loop.c
@@ -74,6 +74,17 @@ scan_poll_results(int ret)
 
        for (clp = clnt_list.tqh_first; clp != NULL; clp = clp->list.tqe_next)
        {
+               i = clp->gssd_poll_index;
+               if (i >= 0 && pollarray[i].revents) {
+                       if (pollarray[i].revents & POLLHUP)
+                               dir_changed = 1;
+                       if (pollarray[i].revents & POLLIN)
+                               handle_gssd_upcall(clp);
+                       pollarray[clp->gssd_poll_index].revents = 0;
+                       ret--;
+                       if (!ret)
+                               break;
+               }
                i = clp->krb5_poll_index;
                if (i >= 0 && pollarray[i].revents) {
                        if (pollarray[i].revents & POLLHUP)

diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index b4c7ae0e176a686518d2f9aa1b1561e65ba5ca7f..5897ae6ac13074a09d019922ca7ddf2449e8fb0f 100644 (file)
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -73,6 +73,7 @@
 #include "krb5_util.h"
 #include "context.h"
 #include "nfsrpc.h"
+#include "nfslib.h"
 
 /*
  * pollarray:
@@ -88,9 +89,11 @@
  *      {rpc_pipefs}/{dir}/clntXX/krb5    : read uid for which kernel wants
  *                                         a context, write the resulting context
  *      {rpc_pipefs}/{dir}/clntXX/info    : stores info such as server name
+ *      {rpc_pipefs}/{dir}/clntXX/gssd    : pipe for all gss mechanisms using
+ *                                         a text-based string of parameters
  *
  * Algorithm:
- *      Poll all {rpc_pipefs}/{dir}/clntXX/krb5 files.  When data is ready,
+ *      Poll all {rpc_pipefs}/{dir}/clntXX/YYYY files.  When data is ready,
  *      read and process; performs rpcsec_gss context initialization protocol to
  *      get a cred for that user.  Writes result to corresponding krb5 file
  *      in a form the kernel code will understand.
@@ -289,9 +292,13 @@ destroy_client(struct clnt_info *clp)
        if (clp->spkm3_poll_index != -1)
                memset(&pollarray[clp->spkm3_poll_index], 0,
                                        sizeof(struct pollfd));
+       if (clp->gssd_poll_index != -1)
+               memset(&pollarray[clp->gssd_poll_index], 0,
+                                       sizeof(struct pollfd));
        if (clp->dir_fd != -1) close(clp->dir_fd);
        if (clp->krb5_fd != -1) close(clp->krb5_fd);
        if (clp->spkm3_fd != -1) close(clp->spkm3_fd);
+       if (clp->gssd_fd != -1) close(clp->gssd_fd);
        free(clp->dirname);
        free(clp->servicename);
        free(clp->servername);
@@ -311,8 +318,10 @@ insert_new_clnt(void)
        }
        clp->krb5_poll_index = -1;
        clp->spkm3_poll_index = -1;
+       clp->gssd_poll_index = -1;
        clp->krb5_fd = -1;
        clp->spkm3_fd = -1;
+       clp->gssd_fd = -1;
        clp->dir_fd = -1;
 
        TAILQ_INSERT_HEAD(&clnt_list, clp, list);
@@ -324,17 +333,42 @@ static int
 process_clnt_dir_files(struct clnt_info * clp)
 {
        char    name[PATH_MAX];
+       char    gname[PATH_MAX];
        char    info_file_name[PATH_MAX];
 
-       if (clp->krb5_fd == -1) {
-               snprintf(name, sizeof(name), "%s/krb5", clp->dirname);
-               clp->krb5_fd = open(name, O_RDWR);
+       if (clp->gssd_fd == -1) {
+               snprintf(gname, sizeof(gname), "%s/gssd", clp->dirname);
+               clp->gssd_fd = open(gname, O_RDWR);
        }
-       if (clp->spkm3_fd == -1) {
-               snprintf(name, sizeof(name), "%s/spkm3", clp->dirname);
-               clp->spkm3_fd = open(name, O_RDWR);
+       if (clp->gssd_fd == -1) {
+               if (clp->krb5_fd == -1) {
+                       snprintf(name, sizeof(name), "%s/krb5", clp->dirname);
+                       clp->krb5_fd = open(name, O_RDWR);
+               }
+               if (clp->spkm3_fd == -1) {
+                       snprintf(name, sizeof(name), "%s/spkm3", clp->dirname);
+                       clp->spkm3_fd = open(name, O_RDWR);
+               }
+
+               /* If we opened a gss-specific pipe, let's try opening
+                * the new upcall pipe again. If we succeed, close
+                * gss-specific pipe(s).
+                */
+               if (clp->krb5_fd != -1 || clp->spkm3_fd != -1) {
+                       clp->gssd_fd = open(gname, O_RDWR);
+                       if (clp->gssd_fd != -1) {
+                               if (clp->krb5_fd != -1)
+                                       close(clp->krb5_fd);
+                               clp->krb5_fd = -1;
+                               if (clp->spkm3_fd != -1)
+                                       close(clp->spkm3_fd);
+                               clp->spkm3_fd = -1;
+                       }
+               }
        }
-       if ((clp->krb5_fd == -1) && (clp->spkm3_fd == -1))
+
+       if ((clp->krb5_fd == -1) && (clp->spkm3_fd == -1) &&
+                       (clp->gssd_fd == -1))
                return -1;
        snprintf(info_file_name, sizeof(info_file_name), "%s/info",
                        clp->dirname);
@@ -369,6 +403,15 @@ get_poll_index(int *ind)
 static int
 insert_clnt_poll(struct clnt_info *clp)
 {
+       if ((clp->gssd_fd != -1) && (clp->gssd_poll_index == -1)) {
+               if (get_poll_index(&clp->gssd_poll_index)) {
+                       printerr(0, "ERROR: Too many gssd clients\n");
+                       return -1;
+               }
+               pollarray[clp->gssd_poll_index].fd = clp->gssd_fd;
+               pollarray[clp->gssd_poll_index].events |= POLLIN;
+       }
+
        if ((clp->krb5_fd != -1) && (clp->krb5_poll_index == -1)) {
                if (get_poll_index(&clp->krb5_poll_index)) {
                        printerr(0, "ERROR: Too many krb5 clients\n");
@@ -835,15 +878,13 @@ int create_auth_rpc_client(struct clnt_info *clp,
        goto out;
 }
 
-
 /*
  * this code uses the userland rpcsec gss library to create a krb5
  * context on behalf of the kernel
  */
-void
-handle_krb5_upcall(struct clnt_info *clp)
+static void
+process_krb5_upcall(struct clnt_info *clp, uid_t uid, int fd)
 {
-       uid_t                   uid;
        CLIENT                  *rpc_clnt = NULL;
        AUTH                    *auth = NULL;
        struct authgss_private_data pd;
@@ -859,12 +900,6 @@ handle_krb5_upcall(struct clnt_info *clp)
        token.value = NULL;
        memset(&pd, 0, sizeof(struct authgss_private_data));
 
-       if (read(clp->krb5_fd, &uid, sizeof(uid)) < sizeof(uid)) {
-               printerr(0, "WARNING: failed reading uid from krb5 "
-                           "upcall pipe: %s\n", strerror(errno));
-               goto out;
-       }
-
        if (uid != 0 || (uid == 0 && root_uses_machine_creds == 0)) {
                /* Tell krb5 gss which credentials cache to use */
                for (dirname = ccachesearch; *dirname != NULL; dirname++) {
@@ -941,7 +976,7 @@ handle_krb5_upcall(struct clnt_info *clp)
                goto out_return_error;
        }
 
-       do_downcall(clp->krb5_fd, uid, &pd, &token);
+       do_downcall(fd, uid, &pd, &token);
 
 out:
        if (token.value)
@@ -957,7 +992,7 @@ out:
        return;
 
 out_return_error:
-       do_error_downcall(clp->krb5_fd, uid, -1);
+       do_error_downcall(fd, uid, -1);
        goto out;
 }
 
@@ -965,10 +1000,9 @@ out_return_error:
  * this code uses the userland rpcsec gss library to create an spkm3
  * context on behalf of the kernel
  */
-void
-handle_spkm3_upcall(struct clnt_info *clp)
+static void
+process_spkm3_upcall(struct clnt_info *clp, uid_t uid, int fd)
 {
-       uid_t                   uid;
        CLIENT                  *rpc_clnt = NULL;
        AUTH                    *auth = NULL;
        struct authgss_private_data pd;
@@ -979,12 +1013,6 @@ handle_spkm3_upcall(struct clnt_info *clp)
        token.length = 0;
        token.value = NULL;
 
-       if (read(clp->spkm3_fd, &uid, sizeof(uid)) < sizeof(uid)) {
-               printerr(0, "WARNING: failed reading uid from spkm3 "
-                        "upcall pipe: %s\n", strerror(errno));
-               goto out;
-       }
-
        if (create_auth_rpc_client(clp, &rpc_clnt, &auth, uid, AUTHTYPE_SPKM3)) {
                printerr(0, "WARNING: Failed to create spkm3 context for "
                            "user with uid %d\n", uid);
@@ -1005,7 +1033,7 @@ handle_spkm3_upcall(struct clnt_info *clp)
                goto out_return_error;
        }
 
-       do_downcall(clp->spkm3_fd, uid, &pd, &token);
+       do_downcall(fd, uid, &pd, &token);
 
 out:
        if (token.value)
@@ -1017,6 +1045,101 @@ out:
        return;
 
 out_return_error:
-       do_error_downcall(clp->spkm3_fd, uid, -1);
+       do_error_downcall(fd, uid, -1);
        goto out;
 }
+
+void
+handle_krb5_upcall(struct clnt_info *clp)
+{
+       uid_t                   uid;
+
+       if (read(clp->krb5_fd, &uid, sizeof(uid)) < sizeof(uid)) {
+               printerr(0, "WARNING: failed reading uid from krb5 "
+                           "upcall pipe: %s\n", strerror(errno));
+               return;
+       }
+
+       return process_krb5_upcall(clp, uid, clp->krb5_fd);
+}
+
+void
+handle_spkm3_upcall(struct clnt_info *clp)
+{
+       uid_t                   uid;
+
+       if (read(clp->spkm3_fd, &uid, sizeof(uid)) < sizeof(uid)) {
+               printerr(0, "WARNING: failed reading uid from spkm3 "
+                        "upcall pipe: %s\n", strerror(errno));
+               return;
+       }
+
+       return process_spkm3_upcall(clp, uid, clp->spkm3_fd);
+}
+
+void
+handle_gssd_upcall(struct clnt_info *clp)
+{
+       uid_t                   uid;
+       char                    *lbuf = NULL;
+       int                     lbuflen = 0;
+       char                    *p;
+       char                    *mech = NULL;
+
+       printerr(1, "handling gssd upcall (%s)\n", clp->dirname);
+
+       if (readline(clp->gssd_fd, &lbuf, &lbuflen) != 1) {
+               printerr(0, "WARNING: handle_gssd_upcall: "
+                           "failed reading request\n");
+               return;
+       }
+       printerr(2, "%s: '%s'\n", __func__, lbuf);
+
+       /* find the mechanism name */
+       if ((p = strstr(lbuf, "mech=")) != NULL) {
+               mech = malloc(lbuflen);
+               if (!mech)
+                       goto out;
+               if (sscanf(p, "mech=%s", mech) != 1) {
+                       printerr(0, "WARNING: handle_gssd_upcall: "
+                                   "failed to parse gss mechanism name "
+                                   "in upcall string '%s'\n", lbuf);
+                       goto out;
+               }
+       } else {
+               printerr(0, "WARNING: handle_gssd_upcall: "
+                           "failed to find gss mechanism name "
+                           "in upcall string '%s'\n", lbuf);
+               goto out;
+       }
+
+       /* read uid */
+       if ((p = strstr(lbuf, "uid=")) != NULL) {
+               if (sscanf(p, "uid=%d", &uid) != 1) {
+                       printerr(0, "WARNING: handle_gssd_upcall: "
+                                   "failed to parse uid "
+                                   "in upcall string '%s'\n", lbuf);
+                       goto out;
+               }
+       } else {
+               printerr(0, "WARNING: handle_gssd_upcall: "
+                           "failed to find uid "
+                           "in upcall string '%s'\n", lbuf);
+               goto out;
+       }
+
+
+       if (strcmp(mech, "krb5") == 0)
+               process_krb5_upcall(clp, uid, clp->gssd_fd);
+       else if (strcmp(mech, "spkm3") == 0)
+               process_spkm3_upcall(clp, uid, clp->gssd_fd);
+       else
+               printerr(0, "WARNING: handle_gssd_upcall: "
+                           "received unknown gss mech '%s'\n", mech);
+
+out:
+       free(lbuf);
+       free(mech);
+       return; 
+}
+