Add parse_attr_list_ex() helper function

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

2 files changed, 153 insertions, 0 deletions

diff --git a/src/responder/common/responder.h b/src/responder/common/responder.h
index e3c0f2267..02a215ced 100644
--- a/src/responder/common/responder.h
+++ b/src/responder/common/responder.h
@@ -329,4 +329,6 @@ sss_parse_inp_send(TALLOC_CTX *mem_ctx, struct resp_ctx *rctx,
 errno_t sss_parse_inp_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
                            char **_name, char **_domname);
 
+const char **parse_attr_list_ex(TALLOC_CTX *mem_ctx, const char *conf_str,
+                                const char **defaults);
 #endif /* __SSS_RESPONDER_H__ */
diff --git a/src/responder/common/responder_utils.c b/src/responder/common/responder_utils.c
new file mode 100644
index 000000000..815b61b39
--- /dev/null
+++ b/src/responder/common/responder_utils.c
@@ -0,0 +1,151 @@
+
+/*
+   SSSD
+
+   Common Responder utility functions
+
+   Copyright (C) Sumit Bose <sbose@redhat.com> 2014
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <talloc.h>
+
+#include "util/util.h"
+
+static inline bool
+attr_in_list(const char **list, size_t nlist, const char *str)
+{
+    size_t i;
+
+    for (i = 0; i < nlist; i++) {
+        if (strcasecmp(list[i], str) == 0) {
+            break;
+        }
+    }
+
+    return (i < nlist) ? true : false;
+}
+
+const char **parse_attr_list_ex(TALLOC_CTX *mem_ctx, const char *conf_str,
+                                const char **defaults)
+{
+    TALLOC_CTX *tmp_ctx;
+    errno_t ret;
+    const char **list = NULL;
+    const char **res = NULL;
+    int list_size;
+    char **conf_list = NULL;
+    int conf_list_size = 0;
+    const char **allow = NULL;
+    const char **deny = NULL;
+    int ai = 0, di = 0, li = 0;
+    int i;
+
+    tmp_ctx = talloc_new(NULL);
+    if (tmp_ctx == NULL) {
+        return NULL;
+    }
+
+    if (conf_str) {
+        ret = split_on_separator(tmp_ctx, conf_str, ',', true, true,
+                                 &conf_list, &conf_list_size);
+        if (ret != EOK) {
+            DEBUG(SSSDBG_OP_FAILURE,
+                  "Cannot parse attribute ACL list  %s: %d\n", conf_str, ret);
+            goto done;
+        }
+
+        allow = talloc_zero_array(tmp_ctx, const char *, conf_list_size);
+        deny = talloc_zero_array(tmp_ctx, const char *, conf_list_size);
+        if (allow == NULL || deny == NULL) {
+            goto done;
+        }
+    }
+
+    for (i = 0; i < conf_list_size; i++) {
+        switch (conf_list[i][0]) {
+            case '+':
+                allow[ai] = conf_list[i] + 1;
+                ai++;
+                continue;
+            case '-':
+                deny[di] = conf_list[i] + 1;
+                di++;
+                continue;
+            default:
+                DEBUG(SSSDBG_CRIT_FAILURE, "ACL values must start with "
+                      "either '+' (allow) or '-' (deny), got '%s'\n",
+                      conf_list[i]);
+                goto done;
+        }
+    }
+
+    /* Assume the output will have to hold defaults and all the configured,
+     * values, resize later
+     */
+    list_size = 0;
+    if (defaults != NULL) {
+        while (defaults[list_size]) {
+            list_size++;
+        }
+    }
+    list_size += conf_list_size;
+
+    list = talloc_zero_array(tmp_ctx, const char *, list_size + 1);
+    if (list == NULL) {
+        goto done;
+    }
+
+    /* Start by copying explicitly allowed attributes */
+    for (i = 0; i < ai; i++) {
+        /* if the attribute is explicitly denied, skip it */
+        if (attr_in_list(deny, di, allow[i])) {
+            continue;
+        }
+
+        list[li] = talloc_strdup(list, allow[i]);
+        if (list[li] == NULL) {
+            goto done;
+        }
+        li++;
+
+        DEBUG(SSSDBG_TRACE_INTERNAL,
+              "Added allowed attr %s to whitelist\n", allow[i]);
+    }
+
+    /* Add defaults */
+    if (defaults != NULL) {
+        for (i = 0; defaults[i]; i++) {
+            /* if the attribute is explicitly denied, skip it */
+            if (attr_in_list(deny, di, defaults[i])) {
+                continue;
+            }
+
+            list[li] = talloc_strdup(list, defaults[i]);
+            if (list[li] == NULL) {
+                goto done;
+            }
+            li++;
+
+            DEBUG(SSSDBG_TRACE_INTERNAL,
+                  "Added default attr %s to whitelist\n", defaults[i]);
+        }
+    }
+
+    res = talloc_steal(mem_ctx, list);
+done:
+    talloc_free(tmp_ctx);
+    return res;
+}