Add a new option to override home directory value

https://fedorahosted.org/sssd/ticket/551

3 files changed, 140 insertions, 1 deletions

diff --git a/src/responder/nss/nsssrv.c b/src/responder/nss/nsssrv.c
index fe66c0d4d..000578dde 100644
--- a/src/responder/nss/nsssrv.c
+++ b/src/responder/nss/nsssrv.c
@@ -110,6 +110,11 @@ static int nss_get_config(struct nss_ctx *nctx,
                             &nctx->pwfield);
     if (ret != EOK) goto done;
 
+    ret = confdb_get_string(cdb, nctx, CONFDB_NSS_CONF_ENTRY,
+                            CONFDB_NSS_OVERRIDE_HOMEDIR, NULL,
+                            &nctx->override_homedir);
+    if (ret != EOK) goto done;
+
     ret = 0;
 done:
     talloc_free(tmpctx);
diff --git a/src/responder/nss/nsssrv.h b/src/responder/nss/nsssrv.h
index 062d937fc..e3e774f99 100644
--- a/src/responder/nss/nsssrv.h
+++ b/src/responder/nss/nsssrv.h
@@ -57,6 +57,8 @@ struct nss_ctx {
     bool filter_users_in_groups;
 
     char *pwfield;
+
+    char *override_homedir;
 };
 
 struct nss_packet;
diff --git a/src/responder/nss/nsssrv_cmd.c b/src/responder/nss/nsssrv_cmd.c
index 6ab32abd0..c8021a72d 100644
--- a/src/responder/nss/nsssrv_cmd.c
+++ b/src/responder/nss/nsssrv_cmd.c
@@ -169,6 +169,114 @@ struct setent_ctx {
 /****************************************************************************
  * PASSWD db related functions
  ***************************************************************************/
+char *expand_homedir_template(TALLOC_CTX *mem_ctx, const char *template,
+                              const char *username, uint32_t uid,
+                              const char *domain)
+{
+    char *copy;
+    char *p;
+    char *n;
+    char *result = NULL;
+    char *res = NULL;
+    TALLOC_CTX *tmp_ctx = NULL;
+
+    if (template == NULL) {
+        DEBUG(1, ("Missing template.\n"));
+        return NULL;
+    }
+
+    tmp_ctx = talloc_new(NULL);
+    if (!tmp_ctx) return NULL;
+
+    copy = talloc_strdup(tmp_ctx, template);
+    if (copy == NULL) {
+        DEBUG(1, ("talloc_strdup failed.\n"));
+        goto done;
+    }
+
+    result = talloc_strdup(tmp_ctx, "");
+    if (result == NULL) {
+        DEBUG(1, ("talloc_strdup failed.\n"));
+        goto done;
+    }
+
+    p = copy;
+    while ( (n = strchr(p, '%')) != NULL) {
+        *n = '\0';
+        n++;
+        if ( *n == '\0' ) {
+            DEBUG(1, ("format error, single %% at the end of the template.\n"));
+            goto done;
+        }
+        switch( *n ) {
+            case 'u':
+                if (username == NULL) {
+                    DEBUG(1, ("Cannot expand user name template "
+                              "because user name is empty.\n"));
+                    goto done;
+                }
+                result = talloc_asprintf_append(result, "%s%s", p,
+                                                username);
+                break;
+
+            case 'U':
+                if (uid == 0) {
+                    DEBUG(1, ("Cannot expand uid template "
+                              "because uid is invalid.\n"));
+                    goto done;
+                }
+                result = talloc_asprintf_append(result, "%s%d", p,
+                                                uid);
+                break;
+
+            case 'd':
+                if (domain == NULL) {
+                    DEBUG(1, ("Cannot expand domain name template "
+                              "because domain name is empty.\n"));
+                    goto done;
+                }
+                result = talloc_asprintf_append(result, "%s%s", p,
+                                                domain);
+                break;
+
+            case 'f':
+                if (domain == NULL || username == NULL) {
+                    DEBUG(1, ("Cannot expand fully qualified name template "
+                              "because domain or user name is empty.\n"));
+                    goto done;
+                }
+                result = talloc_asprintf_append(result, "%s%s@%s", p,
+                                                username, domain);
+                break;
+
+            case '%':
+                result = talloc_asprintf_append(result, "%s%%", p);
+                break;
+
+            default:
+                DEBUG(1, ("format error, unknown template [%%%c].\n", *n));
+                goto done;
+        }
+
+        if (result == NULL) {
+            DEBUG(1, ("talloc_asprintf_append failed.\n"));
+            goto done;
+        }
+
+        p = n + 1;
+    }
+
+    result = talloc_asprintf_append(result, "%s", p);
+    if (result == NULL) {
+        DEBUG(1, ("talloc_asprintf_append failed.\n"));
+        goto done;
+    }
+
+    res = talloc_move(mem_ctx, &result);
+done:
+    talloc_zfree(tmp_ctx);
+    return res;
+}
 
 static gid_t get_gid_override(struct ldb_message *msg,
                               struct sss_domain_info *dom)
@@ -178,6 +286,25 @@ static gid_t get_gid_override(struct ldb_message *msg,
         ldb_msg_find_attr_as_uint64(msg, SYSDB_GIDNUM, 0);
 }
 
+static const char *get_homedir_override(TALLOC_CTX *mem_ctx,
+                                        struct ldb_message *msg,
+                                        struct nss_ctx *nctx,
+                                        struct sss_domain_info *dom,
+                                        const char *name,
+                                        uint32_t uid)
+{
+    if (dom->override_homedir) {
+        return expand_homedir_template(mem_ctx, dom->override_homedir,
+                                       name, uid, dom->name);
+    } else if (nctx->override_homedir) {
+        return expand_homedir_template(mem_ctx, nctx->override_homedir,
+                                       name, uid, dom->name);
+    }
+
+    return talloc_strdup(mem_ctx,
+            ldb_msg_find_attr_as_string(msg, SYSDB_HOMEDIR, NULL));
+}
+
 static int fill_pwent(struct sss_packet *packet,
                       struct sss_domain_info *dom,
                       struct nss_ctx *nctx,
@@ -203,6 +330,7 @@ static int fill_pwent(struct sss_packet *packet,
     const char *namefmt = nctx->rctx->names->fq_fmt;
     bool packet_initialized = false;
     int ncret;
+    TALLOC_CTX *tmp_ctx = NULL;
 
     if (add_domain) dom_len = strlen(domain);
 
@@ -210,6 +338,9 @@ static int fill_pwent(struct sss_packet *packet,
 
     num = 0;
     for (i = 0; i < *count; i++) {
+        talloc_zfree(tmp_ctx);
+        tmp_ctx = talloc_new(NULL);
+
         msg = msgs[i];
 
         name = ldb_msg_find_attr_as_string(msg, SYSDB_NAME, NULL);
@@ -241,7 +372,7 @@ static int fill_pwent(struct sss_packet *packet,
         }
 
         gecos = ldb_msg_find_attr_as_string(msg, SYSDB_GECOS, NULL);
-        homedir = ldb_msg_find_attr_as_string(msg, SYSDB_HOMEDIR, NULL);
+        homedir = get_homedir_override(tmp_ctx, msg, nctx, dom, name, uid);
         shell = ldb_msg_find_attr_as_string(msg, SYSDB_SHELL, NULL);
 
         if (!gecos) gecos = "";
@@ -306,6 +437,7 @@ static int fill_pwent(struct sss_packet *packet,
 
         num++;
     }
+    talloc_zfree(tmp_ctx);
 
 done:
     *count = i;