NEW CLIENT: plugin for NFSv4 rpc.idmapd

Implementation of design document:
https://fedorahosted.org/sssd/wiki/DesignDocs/rpc.idmapd%20plugin

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

1 files changed, 571 insertions, 0 deletions

diff --git a/src/sss_client/nfs/sss_nfs_client.c b/src/sss_client/nfs/sss_nfs_client.c
new file mode 100644
index 000000000..64cb67a8b
--- /dev/null
+++ b/src/sss_client/nfs/sss_nfs_client.c
@@ -0,0 +1,571 @@
+/*
+   SSSD
+
+   NFS Client
+
+   Copyright (C) Noam Meltzer <noam@primarydata.com>    2013-2014
+   Copyright (C) Noam Meltzer <tsnoam@gmail.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/>.
+*/
+
+#define _GNU_SOURCE
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <string.h>
+
+#include <nfsidmap.h>
+#include "nfsidmap_internal.h"
+
+#include "sss_client/sss_cli.h"
+#include "sss_client/nss_mc.h"
+
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+#define PLUGIN_NAME                 "sss_nfs"
+#define CONF_SECTION                "sss_nfs"
+#define CONF_USE_MC                 "memcache"
+#define REPLY_ID_OFFSET             (8)
+#define REPLY_NAME_OFFSET           (REPLY_ID_OFFSET + 8)
+#define BUF_LEN                     (4096)
+#define USE_MC_DEFAULT              true
+
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+static char sss_nfs_plugin_name[]   = PLUGIN_NAME;
+static char nfs_conf_sect[]         = CONF_SECTION;
+static char nfs_conf_use_mc[]       = CONF_USE_MC;
+
+static bool nfs_use_mc              = USE_MC_DEFAULT;
+
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+/* Forward declarations */
+static int send_recv(uint8_t **repp, size_t *rep_lenp, enum sss_cli_command cmd,
+                     const void *req, size_t req_len);
+static int reply_to_id(id_t *idp, uint8_t *rep, size_t rep_len);
+static int reply_to_name(char *name, size_t len, uint8_t *rep, size_t rep_len);
+
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+/* get from memcache functions */
+static int get_uid_from_mc(id_t *uid, const char *name)
+{
+    int rc = 0;
+    struct passwd pwd;
+    char *buf = NULL;
+    char *p = NULL;
+    size_t buflen = 0;
+    size_t len = 0;
+
+    if (!nfs_use_mc) {
+        return -1;
+    }
+
+    sss_strnlen(name, SSS_NAME_MAX, &len);
+
+    do {
+        buflen += BUF_LEN;
+        if ((p = realloc(buf, buflen)) == NULL) {
+            rc = ENOMEM;
+            goto done;
+        }
+        buf = p;
+        rc = sss_nss_mc_getpwnam(name, len, &pwd, buf, buflen);
+    } while (rc == ERANGE);
+
+    if (rc == 0) {
+        IDMAP_LOG(1, ("found user %s in memcache", name));
+        *uid = pwd.pw_uid;
+    } else {
+        IDMAP_LOG(1, ("user %s not in memcache", name));
+    }
+
+done:
+    free(buf);
+    return rc;
+}
+
+static int get_gid_from_mc(id_t *gid, const char *name)
+{
+    int rc = 0;
+    struct group grp;
+    char *buf = NULL;
+    char *p = NULL;
+    size_t buflen = 0;
+    size_t len;
+
+    if (!nfs_use_mc) {
+        return -1;
+    }
+
+    sss_strnlen(name, SSS_NAME_MAX, &len);
+
+    do {
+        buflen += BUF_LEN;
+        if ((p = realloc(buf, buflen)) == NULL) {
+            rc = ENOMEM;
+            goto done;
+        }
+        buf = p;
+        rc = sss_nss_mc_getgrnam(name, len, &grp, buf, buflen);
+    } while (rc == ERANGE);
+
+    if (rc == 0) {
+        IDMAP_LOG(1, ("found group %s in memcache", name));
+        *gid = grp.gr_gid;
+    } else {
+        IDMAP_LOG(1, ("group %s not in memcache", name));
+    }
+
+done:
+    free(buf);
+    return rc;
+}
+
+static int get_user_from_mc(char *name, size_t len, uid_t uid)
+{
+    int rc;
+    struct passwd pwd;
+    char *buf = NULL;
+    char *p = NULL;
+    size_t buflen = 0;
+    size_t pw_name_len;
+
+    if (!nfs_use_mc) {
+        return -1;
+    }
+
+    do {
+        buflen += BUF_LEN;
+        if ((p = realloc(buf, buflen)) == NULL) {
+            rc = ENOMEM;
+            goto done;
+        }
+        buf = p;
+        rc = sss_nss_mc_getpwuid(uid, &pwd, buf, BUF_LEN);
+    } while (rc == ERANGE);
+
+    if (rc == 0) {
+        pw_name_len = strlen(pwd.pw_name) + 1;
+        if (pw_name_len > len) {
+            IDMAP_LOG(0, ("%s: reply too long; pw_name_len=%lu, len=%lu",
+                          __func__, pw_name_len, len));
+            rc = ENOBUFS;
+        }
+        IDMAP_LOG(1, ("found uid %i in memcache", uid));
+        memcpy(name, pwd.pw_name, pw_name_len);
+    } else {
+        IDMAP_LOG(1, ("uid %i not in memcache", uid));
+    }
+
+done:
+    free(buf);
+    return rc;
+}
+
+static int get_group_from_mc(char *name, size_t len, id_t gid)
+{
+    int rc;
+    struct group grp;
+    char *buf = NULL;
+    char *p = NULL;
+    size_t buflen = 0;
+    size_t gr_name_len;
+
+    if (!nfs_use_mc) {
+        return -1;
+    }
+
+    do {
+        buflen += BUF_LEN;
+        if ((p = realloc(buf, buflen)) == NULL) {
+            rc = ENOMEM;
+            goto done;
+        }
+        buf = p;
+        rc = sss_nss_mc_getgrgid(gid, &grp, buf, BUF_LEN);
+    } while (rc == ERANGE);
+
+    if (rc == 0) {
+        gr_name_len = strlen(grp.gr_name) + 1;
+        if (gr_name_len > len) {
+            IDMAP_LOG(0, ("%s: reply too long; gr_name_len=%lu, len=%lu",
+                          __func__, gr_name_len, len));
+            rc = ENOBUFS;
+        }
+        IDMAP_LOG(1, ("found gid %i in memcache", gid));
+        memcpy(name, grp.gr_name, gr_name_len);
+    } else {
+        IDMAP_LOG(1, ("gid %i not in memcache", gid));
+    }
+
+done:
+    free(buf);
+    return rc;
+}
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+static int name_to_id(const char *name, id_t *id, enum sss_cli_command cmd)
+{
+    int rc;
+    uint8_t *rep = NULL;
+    size_t rep_len = 0;
+    size_t name_len;
+
+    sss_strnlen(name, SSS_NAME_MAX, &name_len);
+
+    rc = send_recv(&rep, &rep_len, cmd, name, name_len + 1);
+    if (rc == 0) {
+        rc = reply_to_id(id, rep, rep_len);
+    }
+
+    free(rep);
+
+    return rc;
+}
+
+static int id_to_name(char *name, size_t len, id_t id,
+                      enum sss_cli_command cmd)
+{
+    int rc;
+    size_t rep_len = 0;
+    size_t req_len = sizeof(id_t);
+    uint8_t *rep = NULL;
+    uint8_t req[req_len];
+
+    memcpy(req, &id, req_len);
+    rc = send_recv(&rep, &rep_len, cmd, &req, req_len);
+    if (rc == 0) {
+        rc = reply_to_name(name, len, rep, rep_len);
+    }
+
+    free(rep);
+
+    return rc;
+}
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+static int send_recv(uint8_t **rep, size_t *rep_len, enum sss_cli_command cmd,
+                     const void *req, size_t req_len)
+{
+    int err = 0;
+    enum nss_status req_rc;
+    struct sss_cli_req_data rd;
+
+    rd.data = req;
+    rd.len = req_len;
+
+    sss_nss_lock();
+    req_rc = sss_nss_make_request(cmd, &rd, rep, rep_len, &err);
+    sss_nss_unlock();
+
+    if (req_rc == NSS_STATUS_NOTFOUND) {
+        return ENOENT;
+    }
+    if (req_rc != NSS_STATUS_SUCCESS) {
+        IDMAP_LOG(0, ("no-make-request; err=%i", err));
+        return EPIPE;
+    }
+
+    return 0;
+}
+
+static int reply_to_id(id_t *idp, uint8_t *rep, size_t rep_len)
+{
+    int rc = 0;
+    id_t id;
+    uint32_t num_results = 0;
+
+    if (rep_len < sizeof(uint32_t)) {
+        IDMAP_LOG(0, ("%s: reply too small; rep_len=%lu", __func__, rep_len));
+        rc = EBADMSG;
+        goto done;
+    }
+
+    SAFEALIGN_COPY_UINT32(&num_results, rep, NULL);
+    if (num_results > 1) {
+        IDMAP_LOG(0, ("%s: too many results (%lu)", __func__, num_results));
+        rc = EBADMSG;
+        goto done;
+    }
+    if (num_results == 0) {
+        rc = ENOENT;
+        goto done;
+    }
+    if (rep_len < sizeof(uint32_t) + REPLY_ID_OFFSET) {
+        IDMAP_LOG(0, ("%s: reply too small(2); rep_len=%lu", __func__,
+                      rep_len));
+        rc = EBADMSG;
+        goto done;
+    }
+
+    SAFEALIGN_COPY_UINT32(&id, rep + REPLY_ID_OFFSET, NULL);
+    *idp = id;
+
+done:
+    return rc;
+}
+
+static int reply_to_name(char *name, size_t len, uint8_t *rep, size_t rep_len)
+{
+    int rc = 0;
+    uint32_t num_results = 0;
+    const char *buf;
+    size_t buf_len;
+    size_t offset;
+
+    if (rep_len < sizeof(uint32_t)) {
+        IDMAP_LOG(0, ("%s: reply too small; rep_len=%lu", __func__, rep_len));
+        rc = EBADMSG;
+        goto done;
+    }
+
+    SAFEALIGN_COPY_UINT32(&num_results, rep, NULL);
+    if (num_results > 1) {
+        IDMAP_LOG(0, ("%s: too many results (%lu)", __func__, num_results));
+        rc = EBADMSG;
+        goto done;
+    }
+    if (num_results == 0) {
+        rc = ENOENT;
+        goto done;
+    }
+    if (rep_len < sizeof(uint32_t) + REPLY_NAME_OFFSET) {
+        IDMAP_LOG(0, ("%s: reply too small(2); rep_len=%lu", __func__,
+                      rep_len));
+        rc = EBADMSG;
+        goto done;
+    }
+
+    buf = (const char *)(rep + REPLY_NAME_OFFSET);
+    buf_len = rep_len - REPLY_NAME_OFFSET;
+    offset = 0;
+    rc = sss_readrep_copy_string(buf, &offset, &buf_len, &len, &name, NULL);
+    if (rc != 0) {
+        rc = -rc;
+    }
+
+done:
+    return rc;
+}
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+/* configuration parsing aids */
+static bool str_equal(const char *s1, const char *s2)
+{
+    bool res = false;
+    size_t len1;
+    size_t len2;
+
+    len1 = strlen(s1);
+    len2 = strlen(s2);
+
+    if (len1 == len2) {
+        res = (strncasecmp(s1, s2, len1) == 0);
+    }
+
+    return res;
+}
+
+static int nfs_conf_get_bool(char *sect, char *attr, int def)
+{
+    int res;
+    char *val;
+
+    res = def;
+    val = conf_get_str(sect, attr);
+    if (val) {
+        res = (str_equal("1", val) ||
+               str_equal("yes", val) ||
+               str_equal("true", val) ||
+               str_equal("on", val));
+    }
+
+    return res;
+}
+
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+/* libnfsidmap return-code aids */
+
+/*
+ * we only want to return 0 or ENOENT; otherwise libnfsidmap will stop
+ * translation instead of proceeding to the next translation plugin
+ */
+int normalise_rc(int rc) {
+    int res;
+
+    res = rc;
+    if (res != 0 && res != ENOENT) {
+        res = ENOENT;
+    }
+
+    return res;
+}
+
+/* log the actual rc from our code (to be used before normalising the rc) */
+void log_actual_rc(const char *trans_name, int rc) {
+    char tmp[80];
+    IDMAP_LOG(1, ("%s: rc=%i msg=%s", trans_name, rc,
+                  strerror_r(rc, tmp, sizeof(tmp))));
+}
+
+
+/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+/* The external interface */
+static int sss_nfs_init(void)
+{
+    nfs_use_mc = nfs_conf_get_bool(nfs_conf_sect, nfs_conf_use_mc,
+                                   USE_MC_DEFAULT);
+    IDMAP_LOG(1, ("%s: use memcache: %i", __func__, nfs_use_mc));
+
+    return 0;
+}
+
+static int sss_nfs_princ_to_ids(char *secname, char *princ, uid_t *uid,
+                                gid_t *gid, extra_mapping_params **ex)
+{
+    IDMAP_LOG(0, ("%s: not implemented", __func__));
+    return -ENOENT;
+}
+
+static int sss_nfs_name_to_uid(char *name, uid_t *uid)
+{
+    int rc;
+    size_t name_len = 0;
+
+    if (name == NULL) {
+        IDMAP_LOG(0, ("%s: name is null", __func__));
+        return -EINVAL;
+    }
+    if (uid == NULL) {
+        IDMAP_LOG(0, ("%s: uid is null", __func__));
+        return -EINVAL;
+    }
+
+    rc = sss_strnlen(name, SSS_NAME_MAX, &name_len);
+    if (rc != 0) {
+        IDMAP_LOG(0, ("%s: no-strnlen; rc=%i", __func__, rc));
+        return -rc;
+    }
+
+    rc = get_uid_from_mc(uid, name);
+    if (rc != 0) {
+        rc = name_to_id(name, uid, SSS_NSS_GETPWNAM);
+    }
+
+    log_actual_rc(__func__, rc);
+    rc = normalise_rc(rc);
+
+    return -rc;
+}
+
+static int sss_nfs_name_to_gid(char *name, gid_t *gid)
+{
+    int rc;
+    size_t name_len = 0;
+
+    if (name == NULL) {
+        IDMAP_LOG(0, ("%s: name is null", __func__));
+        return -EINVAL;
+    }
+    if (gid == NULL) {
+        IDMAP_LOG(0, ("%s: gid is null", __func__));
+        return -EINVAL;
+    }
+
+    rc = sss_strnlen(name, SSS_NAME_MAX, &name_len);
+    if (rc != 0) {
+        IDMAP_LOG(0, ("%s: no-strnlen; rc=%i", __func__, rc));
+        return -rc;
+    }
+
+    rc = get_gid_from_mc(gid, name);
+    if (rc != 0) {
+        rc = name_to_id(name, gid, SSS_NSS_GETGRNAM);
+    }
+
+    log_actual_rc(__func__, rc);
+    rc = normalise_rc(rc);
+
+    return -rc;
+}
+
+static int sss_nfs_uid_to_name(uid_t uid, char *domain, char *name, size_t len)
+{
+    int rc;
+
+    if (name == NULL) {
+        IDMAP_LOG(0, ("%s: name is null", __func__));
+        return -EINVAL;
+    }
+
+    rc = get_user_from_mc(name, len, uid);
+    if (rc != 0) {
+        rc = id_to_name(name, len, uid, SSS_NSS_GETPWUID);
+    }
+
+    log_actual_rc(__func__, rc);
+    rc = normalise_rc(rc);
+
+    return -rc;
+}
+
+static int sss_nfs_gid_to_name(gid_t gid, char *domain, char *name, size_t len)
+{
+    int rc;
+
+    if (name == NULL) {
+        IDMAP_LOG(0, ("%s: name is null", __func__));
+        return -EINVAL;
+    }
+
+    rc = get_group_from_mc(name, len, gid);
+    if (rc != 0) {
+        rc = id_to_name(name, len, gid, SSS_NSS_GETGRGID);
+    }
+
+    log_actual_rc(__func__, rc);
+    rc = normalise_rc(rc);
+
+    return -rc;
+}
+
+static int sss_nfs_gss_princ_to_grouplist(
+    char *secname, char *princ, gid_t *groups, int *ngroups,
+    extra_mapping_params **ex)
+{
+    IDMAP_LOG(0, ("%s: not implemented", __func__));
+    return -ENOENT;
+}
+
+static struct trans_func s_sss_nfs_trans = {
+    .name = sss_nfs_plugin_name,
+    .init = sss_nfs_init,
+    .princ_to_ids = sss_nfs_princ_to_ids,
+    .name_to_uid = sss_nfs_name_to_uid,
+    .name_to_gid = sss_nfs_name_to_gid,
+    .uid_to_name = sss_nfs_uid_to_name,
+    .gid_to_name = sss_nfs_gid_to_name,
+    .gss_princ_to_grouplist = sss_nfs_gss_princ_to_grouplist,
+};
+
+struct trans_func *libnfsidmap_plugin_init(void)
+{
+    return (&s_sss_nfs_trans);
+}