NSS: Initgr memory cache should work with fq names

We need to stored two versions of name to the initgroups memory cache.
Otherwise it could be stored many times if sssd is configured with
case_sensitive = false. It would be impossible to invalidate all
version of names after user login. As a result of this wrong user
groups could be returned from initgroups memory cache.

Therefore we store raw name provided by glibc function
and internal sanitized fully qualified name,
which is unique for particular user.

This patch also increase average space for initgroups
because there are also stored two quite long names in case of
fq names.

Resolves:
https://fedorahosted.org/sssd/ticket/2712

Reviewed-by: Michal Židek <mzidek@redhat.com>

4 files changed, 49 insertions, 16 deletions

diff --git a/src/responder/nss/nsssrv_cmd.c b/src/responder/nss/nsssrv_cmd.c
index 778618e40..e754245ea 100644
--- a/src/responder/nss/nsssrv_cmd.c
+++ b/src/responder/nss/nsssrv_cmd.c
@@ -1387,6 +1387,7 @@ static int nss_cmd_getbynam(enum sss_cli_command cmd, struct cli_ctx *cctx)
     }
 
     rawname = (const char *)body;
+    dctx->mc_name = rawname;
 
     DEBUG(SSSDBG_TRACE_FUNC, "Running command [%d] with input [%s].\n",
                                dctx->cmdctx->cmd, rawname);
@@ -3976,6 +3977,13 @@ void nss_update_initgr_memcache(struct nss_ctx *nctx,
     }
 
     if (changed) {
+        char *fq_name = sss_tc_fqname(tmp_ctx, dom->names, dom, name);
+        if (!fq_name) {
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  "Could not create fq name\n");
+            goto done;
+        }
+
         for (i = 0; i < gnum; i++) {
             id = groups[i];
 
@@ -3987,7 +3995,7 @@ void nss_update_initgr_memcache(struct nss_ctx *nctx,
             }
         }
 
-        to_sized_string(&delete_name, name);
+        to_sized_string(&delete_name, fq_name);
         ret = sss_mmap_cache_initgr_invalidate(nctx->initgr_mc_ctx,
                                                &delete_name);
         if (ret != EOK && ret != ENOENT) {
@@ -4007,6 +4015,7 @@ static int fill_initgr(struct sss_packet *packet,
                        struct sss_domain_info *dom,
                        struct ldb_result *res,
                        struct nss_ctx *nctx,
+                       const char *mc_name,
                        const char *name)
 {
     uint8_t *body;
@@ -4095,9 +4104,18 @@ static int fill_initgr(struct sss_packet *packet,
     }
 
     if (nctx->initgr_mc_ctx) {
-        to_sized_string(&rawname, name);
+        struct sized_string unique_name;
+        char *fq_name = sss_tc_fqname(packet, dom->names, dom, name);
+        if (!fq_name) {
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  "Could not create fq name\n");
+            return ENOMEM;
+        }
+
+        to_sized_string(&rawname, mc_name);
+        to_sized_string(&unique_name, fq_name);
         ret = sss_mmap_cache_initgr_store(&nctx->initgr_mc_ctx, &rawname,
-                                          num - skipped, gids);
+                                          &unique_name, num - skipped, gids);
         if (ret != EOK && ret != ENOMEM) {
             DEBUG(SSSDBG_CRIT_FAILURE,
                   "Failed to store user %s(%s) in mmap cache!\n",
@@ -4125,7 +4143,7 @@ static int nss_cmd_initgr_send_reply(struct nss_dom_ctx *dctx)
     }
 
     ret = fill_initgr(cctx->creq->out, dctx->domain, dctx->res, nctx,
-                      dctx->rawname);
+                      dctx->mc_name, cmdctx->name);
     if (ret) {
         return ret;
     }
@@ -4173,8 +4191,10 @@ static int nss_cmd_initgroups_search(struct nss_dom_ctx *dctx)
         name = sss_get_cased_name(dctx, cmdctx->name, dom->case_sensitive);
         if (!name) return ENOMEM;
 
-        name = sss_reverse_replace_space(dctx, name,
+        name = sss_reverse_replace_space(cmdctx, name,
                                          nctx->rctx->override_space);
+        /* save name so it can be used in initgr reply */
+        cmdctx->name = name;
         if (name == NULL) {
             DEBUG(SSSDBG_CRIT_FAILURE,
                   "sss_reverse_replace_space failed\n");
diff --git a/src/responder/nss/nsssrv_mmap_cache.c b/src/responder/nss/nsssrv_mmap_cache.c
index ab9e769b1..62f4c543c 100644
--- a/src/responder/nss/nsssrv_mmap_cache.c
+++ b/src/responder/nss/nsssrv_mmap_cache.c
@@ -31,8 +31,8 @@
 #define SSS_AVG_PASSWD_PAYLOAD (MC_SLOT_SIZE * 4)
 /* short group name and no gids (private user group */
 #define SSS_AVG_GROUP_PAYLOAD (MC_SLOT_SIZE * 3)
-/* average place for 40 supplementary groups */
-#define SSS_AVG_INITGROUP_PAYLOAD (MC_SLOT_SIZE * 4)
+/* average place for 40 supplementary groups + 2 names */
+#define SSS_AVG_INITGROUP_PAYLOAD (MC_SLOT_SIZE * 5)
 
 #define MC_NEXT_BARRIER(val) ((((val) + 1) & 0x00ffffff) | 0xf0000000)
 
@@ -965,6 +965,7 @@ done:
 
 errno_t sss_mmap_cache_initgr_store(struct sss_mc_ctx **_mcc,
                                     struct sized_string *name,
+                                    struct sized_string *unique_name,
                                     uint32_t num_groups,
                                     uint8_t *gids_buf)
 {
@@ -973,6 +974,7 @@ errno_t sss_mmap_cache_initgr_store(struct sss_mc_ctx **_mcc,
     struct sss_mc_initgr_data *data;
     size_t data_len;
     size_t rec_len;
+    size_t pos;
     int ret;
 
     if (mcc == NULL) {
@@ -980,20 +982,22 @@ errno_t sss_mmap_cache_initgr_store(struct sss_mc_ctx **_mcc,
         return EINVAL;
     }
 
-    /* array of gids + name */
-    data_len = num_groups * sizeof(uint32_t) + name->len;
+    /* array of gids + name + unique_name */
+    data_len = num_groups * sizeof(uint32_t) + name->len + unique_name->len;
     rec_len = sizeof(struct sss_mc_rec) + sizeof(struct sss_mc_initgr_data)
               + data_len;
     if (rec_len > mcc->dt_size) {
         return ENOMEM;
     }
 
-    ret = sss_mc_get_record(_mcc, rec_len, name, &rec);
+    /* use unique name for searching potential old records */
+    ret = sss_mc_get_record(_mcc, rec_len, unique_name, &rec);
     if (ret != EOK) {
         return ret;
     }
 
     data = (struct sss_mc_initgr_data *)rec->data;
+    pos = 0;
 
     MC_RAISE_BARRIER(rec);
 
@@ -1001,16 +1005,22 @@ errno_t sss_mmap_cache_initgr_store(struct sss_mc_ctx **_mcc,
      * Use the first key twice.
      */
     sss_mmap_set_rec_header(mcc, rec, rec_len, mcc->valid_time_slot,
-                            name->str, name->len, name->str, name->len);
+                            name->str, name->len,
+                            unique_name->str, unique_name->len);
 
     /* initgroups struct */
-    data->strs_len = name->len;
+    data->strs_len = name->len + unique_name->len;
     data->data_len = data_len;
-    data->reserved = MC_INVALID_VAL32;
     data->num_groups = num_groups;
-    memcpy(data->gids, gids_buf, num_groups * sizeof(uint32_t));
-    memcpy(&data->gids[num_groups], name->str, name->len);
-    data->strs = data->name = MC_PTR_DIFF(&data->gids[num_groups], data);
+    memcpy((char *)data->gids + pos, gids_buf, num_groups * sizeof(uint32_t));
+    pos += num_groups * sizeof(uint32_t);
+
+    memcpy((char *)data->gids + pos, unique_name->str, unique_name->len);
+    data->strs = data->unique_name = MC_PTR_DIFF((char *)data->gids + pos, data);
+    pos += unique_name->len;
+
+    memcpy((char *)data->gids + pos, name->str, name->len);
+    data->name = MC_PTR_DIFF((char *)data->gids + pos, data);
 
     MC_LOWER_BARRIER(rec);
 
diff --git a/src/responder/nss/nsssrv_mmap_cache.h b/src/responder/nss/nsssrv_mmap_cache.h
index b09e4a6f8..b84fbc8ed 100644
--- a/src/responder/nss/nsssrv_mmap_cache.h
+++ b/src/responder/nss/nsssrv_mmap_cache.h
@@ -53,6 +53,7 @@ errno_t sss_mmap_cache_gr_store(struct sss_mc_ctx **_mcc,
 
 errno_t sss_mmap_cache_initgr_store(struct sss_mc_ctx **_mcc,
                                     struct sized_string *name,
+                                    struct sized_string *unique_name,
                                     uint32_t num_groups,
                                     uint8_t *gids_buf);
 
diff --git a/src/responder/nss/nsssrv_private.h b/src/responder/nss/nsssrv_private.h
index e9f00b114..e5a2486f1 100644
--- a/src/responder/nss/nsssrv_private.h
+++ b/src/responder/nss/nsssrv_private.h
@@ -79,6 +79,8 @@ struct nss_dom_ctx {
 
     /* Service-specific */
     const char *protocol;
+
+    const char *mc_name;
 };
 
 struct setent_step_ctx {