sss_nss_idmap: add sss_nss_getorigbyname()

This patch adds an interface to the new SSS_NSS_GETORIGBYNAME request of
the nss responder to libsss_nss_idmap.

The main use case for this new call is to replace sss_nss_getsidbyname()
in the extdom plugin on the FreeIPA server to get more information about
the given object than just the SID which is not available with the
default POSIX interfaces.

Reviewed-by: Pavel Březina <pbrezina@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

3 files changed, 152 insertions, 0 deletions

diff --git a/src/sss_client/idmap/sss_nss_idmap.c b/src/sss_client/idmap/sss_nss_idmap.c
index adb588975..55d8043bd 100644
--- a/src/sss_client/idmap/sss_nss_idmap.c
+++ b/src/sss_client/idmap/sss_nss_idmap.c
@@ -41,6 +41,7 @@ struct output {
     union {
         char *str;
         uint32_t id;
+        struct sss_nss_kv *kv_list;
     } d;
 };
 
@@ -58,6 +59,85 @@ int nss_status_to_errno(enum nss_status nret) {
     return EINVAL;
 }
 
+void sss_nss_free_kv(struct sss_nss_kv *kv_list)
+{
+    size_t c;
+
+    if (kv_list != NULL) {
+        for (c = 0; kv_list[c].key != NULL; c++) {
+            free(kv_list[c].key);
+            free(kv_list[c].value);
+        }
+        free(kv_list);
+    }
+}
+
+static int  buf_to_kv_list(uint8_t *buf, size_t buf_len,
+                           struct sss_nss_kv **kv_list)
+{
+    size_t c;
+    size_t count = 0;
+    struct sss_nss_kv *list;
+    uint8_t *p;
+    int ret;
+
+    for (c = 0; c < buf_len; c++) {
+        if (buf[c] == '\0') {
+            count++;
+        }
+    }
+
+    if ((count % 2) != 0) {
+        return EINVAL;
+    }
+    count /= 2;
+
+    list = calloc((count + 1), sizeof(struct sss_nss_kv));
+    if (list == NULL) {
+        return ENOMEM;
+    }
+
+    p = buf;
+    for (c = 0; c < count; c++) {
+        list[c].key = strdup((char *) p);
+        if (list[c].key == NULL) {
+            ret = ENOMEM;
+            goto done;
+        }
+
+        p = memchr(p, '\0', buf_len - (p - buf));
+        if (p == NULL) {
+            ret = EINVAL;
+            goto done;
+        }
+        p++;
+
+        list[c].value = strdup((char *) p);
+        if (list[c].value == NULL) {
+            ret = ENOMEM;
+            goto done;
+        }
+
+        p = memchr(p, '\0', buf_len - (p - buf));
+        if (p == NULL) {
+            ret = EINVAL;
+            goto done;
+        }
+        p++;
+    }
+
+    *kv_list = list;
+
+    ret = EOK;
+
+done:
+    if (ret != EOK) {
+        sss_nss_free_kv(list);
+    }
+
+    return ret;
+}
+
 static int sss_nss_getyyybyxxx(union input inp, enum sss_cli_command cmd ,
                                struct output *out)
 {
@@ -72,11 +152,13 @@ static int sss_nss_getyyybyxxx(union input inp, enum sss_cli_command cmd ,
     char *str = NULL;
     size_t data_len;
     uint32_t c;
+    struct sss_nss_kv *kv_list;
 
     switch (cmd) {
     case SSS_NSS_GETSIDBYNAME:
     case SSS_NSS_GETNAMEBYSID:
     case SSS_NSS_GETIDBYSID:
+    case SSS_NSS_GETORIGBYNAME:
         ret = sss_strnlen(inp.str, SSS_NAME_MAX, &inp_len);
         if (ret != EOK) {
             return EINVAL;
@@ -153,6 +235,15 @@ static int sss_nss_getyyybyxxx(union input inp, enum sss_cli_command cmd ,
         out->d.id = c;
 
         break;
+    case SSS_NSS_GETORIGBYNAME:
+        ret = buf_to_kv_list(repbuf + DATA_START, data_len, &kv_list);
+        if (ret != EOK) {
+            goto done;
+        }
+
+        out->d.kv_list = kv_list;
+
+        break;
     default:
         ret = EINVAL;
         goto done;
@@ -255,3 +346,25 @@ int sss_nss_getidbysid(const char *sid, uint32_t *id, enum sss_id_type *id_type)
 
     return ret;
 }
+
+int sss_nss_getorigbyname(const char *fq_name, struct sss_nss_kv **kv_list,
+                         enum sss_id_type *type)
+{
+    int ret;
+    union input inp;
+    struct output out;
+
+    if (kv_list == NULL || fq_name == NULL || *fq_name == '\0') {
+        return EINVAL;
+    }
+
+    inp.str = fq_name;
+
+    ret = sss_nss_getyyybyxxx(inp, SSS_NSS_GETORIGBYNAME, &out);
+    if (ret == EOK) {
+        *kv_list = out.d.kv_list;
+        *type = out.type;
+    }
+
+    return ret;
+}
diff --git a/src/sss_client/idmap/sss_nss_idmap.exports b/src/sss_client/idmap/sss_nss_idmap.exports
index 7b8488b2a..8aa470241 100644
--- a/src/sss_client/idmap/sss_nss_idmap.exports
+++ b/src/sss_client/idmap/sss_nss_idmap.exports
@@ -12,3 +12,10 @@ SSS_NSS_IDMAP_0.0.1 {
     local:
         *;
 };
+
+SSS_NSS_IDMAP_0.1.0 {
+    # public functions
+    global:
+        sss_nss_getorigbyname;
+        sss_nss_free_kv;
+} SSS_NSS_IDMAP_0.0.1;
diff --git a/src/sss_client/idmap/sss_nss_idmap.h b/src/sss_client/idmap/sss_nss_idmap.h
index 79dacfbdb..78a8a11c1 100644
--- a/src/sss_client/idmap/sss_nss_idmap.h
+++ b/src/sss_client/idmap/sss_nss_idmap.h
@@ -37,6 +37,11 @@ enum sss_id_type {
     SSS_ID_TYPE_BOTH /* used for user or magic private groups */
 };
 
+struct sss_nss_kv {
+    char *key;
+    char *value;
+};
+
 /**
  * @brief Find SID by fully qualified name
  *
@@ -97,4 +102,31 @@ int sss_nss_getnamebysid(const char *sid, char **fq_name,
 int sss_nss_getidbysid(const char *sid, uint32_t *id,
                        enum sss_id_type *id_type);
 
+/**
+ * @brief Find original data by fully qualified name
+ *
+ * @param[in] fq_name  Fully qualified name of a user or a group
+ * @param[out] kv_list A NULL terminate list of key-value pairs where the key
+ *                     is the attribute name in the cache of SSSD,
+ *                     must be freed by the caller with sss_nss_free_kv()
+ * @param[out] type    Type of the object related to the given name
+ *
+ * @return
+ *  - 0 (EOK): success, sid contains the requested SID
+ *  - ENOENT: requested object was not found in the domain extracted from the given name
+ *  - ENETUNREACH: SSSD does not know how to handle the domain extracted from the given name
+ *  - ENOSYS: this call is not supported by the configured provider
+ *  - EINVAL: input cannot be parsed
+ *  - EIO: remote servers cannot be reached
+ *  - EFAULT: any other error
+ */
+int sss_nss_getorigbyname(const char *fq_name, struct sss_nss_kv **kv_list,
+                          enum sss_id_type *type);
+
+/**
+ * @brief Free key-value list returned by sss_nss_getorigbyname()
+ *
+ * @param[in] kv_list Key-value list returned by sss_nss_getorigbyname().
+ */
+void sss_nss_free_kv(struct sss_nss_kv *kv_list);
 #endif /* SSS_NSS_IDMAP_H_ */