idmap/idmapd/directory_provider_ad.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
 */

/*
 * Retrieve directory information for Active Directory users.
 */

#include <ldap.h>
#include <lber.h>
#include <pwd.h>
#include <malloc.h>
#include <string.h>
#include <stdlib.h>
#include <netdb.h>
#include <libadutils.h>
#include <libuutil.h>
#include <note.h>
#include <assert.h>
#include "directory.h"
#include "directory_private.h"
#include "idmapd.h"
#include <rpcsvc/idmap_prot.h>
#include "directory_server_impl.h"

/*
 * Information required by the function that handles the callback from LDAP
 * when responses are received.
 */
struct cbinfo {
    const char * const *attrs;
    int nattrs;
    directory_entry_rpc *entry;
    const char *domain;
};

static void directory_provider_ad_cb(LDAP *ld, LDAPMessage **ldapres, int rc,
    int qid, void *argp);
static void directory_provider_ad_cb1(LDAP *ld, LDAPMessage *msg,
    struct cbinfo *cbinfo);
static directory_error_t bv_list_dav(directory_values_rpc *lvals,
    struct berval **bv);
static directory_error_t directory_provider_ad_lookup(
    directory_entry_rpc *pent, const char * const * attrs, int nattrs,
    const char *domain, const char *filter);
static directory_error_t get_domain(LDAP *ld, LDAPMessage *ldapres,
    char **domain);
static directory_error_t directory_provider_ad_utils_error(char *func, int rc);

#if defined(DUMP_VALUES)
static void dump_bv_list(const char *attr, struct berval **bv);
#endif

#define MAX_EXTRA_ATTRS 1   /* sAMAccountName */

/*
 * Add an entry to a NULL-terminated list, if it's not already there.
 * Assumes that the list has been allocated large enough for all additions,
 * and prefilled with NULL.
 */
static
void
maybe_add_to_list(const char **list, const char *s)
{
    for (; *list != NULL; list++) {
        if (uu_strcaseeq(*list, s))
            return;
    }
    *list = s;
}

/*
 * Copy a counted attribute list to a NULL-terminated one.
 * In the process, examine the requested attributes and augment
 * the list as required to support any synthesized attributes
 * requested.
 */
static
const char **
copy_and_augment_attr_list(char **req_list, int req_list_len)
{
    const char **new_list;
    int i;

    new_list =
        calloc(req_list_len + MAX_EXTRA_ATTRS + 1, sizeof (*new_list));
    if (new_list == NULL)
        return (NULL);

    (void) memcpy(new_list, req_list, req_list_len * sizeof (char *));

    for (i = 0; i < req_list_len; i++) {
        const char *a = req_list[i];
        /*
         * Note that you must update MAX_EXTRA_ATTRS above if you
         * add to this list.
         */
        if (uu_strcaseeq(a, "x-sun-canonicalName")) {
            maybe_add_to_list(new_list, "sAMAccountName");
            continue;
        }
        /* None needed for x-sun-provider */
    }

    return (new_list);
}

/*
 * Retrieve information by name.
 * Called indirectly through the Directory_provider_static structure.
 */
static
directory_error_t
directory_provider_ad_get(
    directory_entry_rpc *del,
    idmap_utf8str_list *ids,
    char *types,
    idmap_utf8str_list *attrs)
{
    int i;
    const char **attrs2;
    directory_error_t de = NULL;

    /*
     * If we don't have any AD servers handy, we can't find anything.
     * XXX: this should be using our DC, not the GC.
     */
    if (_idmapdstate.num_gcs < 1) {
        return (NULL);
    }

    RDLOCK_CONFIG()

    /* 6835280 spurious lint error if the strlen is in the declaration */
    int len = strlen(_idmapdstate.cfg->pgcfg.default_domain);
    char default_domain[len + 1];
    (void) strcpy(default_domain, _idmapdstate.cfg->pgcfg.default_domain);

    UNLOCK_CONFIG();

    /*
     * Turn our counted-array argument into a NULL-terminated array.
     * At the same time, add in any attributes that we need to support
     * any requested synthesized attributes.
     */
    attrs2 = copy_and_augment_attr_list(attrs->idmap_utf8str_list_val,
        attrs->idmap_utf8str_list_len);
    if (attrs2 == NULL)
        goto nomem;

    for (i = 0; i < ids->idmap_utf8str_list_len; i++) {
        char *vw[3];
        int type;

        /*
         * Extract the type for this particular ID.
         * Advance to the next type, if it's there, else keep
         * using this type until we run out of IDs.
         */
        type = *types;
        if (*(types+1) != '\0')
            types++;

        /*
         * If this entry has already been handled, one way or another,
         * skip it.
         */
        if (del[i].status != DIRECTORY_NOT_FOUND)
            continue;

        char *id = ids->idmap_utf8str_list_val[i];

        /*
         * Allow for expanding every character to \xx, plus some
         * space for the query syntax.
         */
        int id_len = strlen(id);
        char filter[1000 + id_len*3];

        if (type == DIRECTORY_ID_SID[0]) {
            /*
             * Mildly surprisingly, AD appears to allow searching
             * based on text SIDs.  Must be a special case on the
             * server end.
             */
            ldap_build_filter(filter, sizeof (filter),
                "(objectSid=%v)", NULL, NULL, NULL, id, NULL);

            de = directory_provider_ad_lookup(&del[i], attrs2,
                attrs->idmap_utf8str_list_len, NULL, filter);
            if (de != NULL) {
                directory_entry_set_error(&del[i], de);
                de = NULL;
            }
        } else {
            int id_len = strlen(id);
            char name[id_len + 1];
            char domain[id_len + 1];

            split_name(name, domain, id);

            vw[0] = name;

            if (uu_streq(domain, "")) {
                vw[1] = default_domain;
            } else {
                vw[1] = domain;
            }

            if (type == DIRECTORY_ID_USER[0])
                vw[2] = "user";
            else if (type == DIRECTORY_ID_GROUP[0])
                vw[2] = "group";
            else
                vw[2] = "*";

            /*
             * Try samAccountName.
             * Note that here we rely on checking the returned
             * distinguishedName to make sure that we found an
             * entry from the right domain, because there's no
             * attribute we can straightforwardly filter for to
             * match domain.
             *
             * Eventually we should perhaps also try
             * userPrincipalName.
             */
            ldap_build_filter(filter, sizeof (filter),
                "(&(samAccountName=%v1)(objectClass=%v3))",
                NULL, NULL, NULL, NULL, vw);

            de = directory_provider_ad_lookup(&del[i], attrs2,
                attrs->idmap_utf8str_list_len, vw[1], filter);
            if (de != NULL) {
                directory_entry_set_error(&del[i], de);
                de = NULL;
            }
        }
    }

    de = NULL;

    goto out;

nomem:
    de = directory_error("ENOMEM.AD",
        "Out of memory during AD lookup", NULL);
out:
    free(attrs2);
    return (de);
}

/*
 * Note that attrs is NULL terminated, and that nattrs is the number
 * of attributes requested by the user... which might be fewer than are
 * in attrs because of attributes that we need for our own processing.
 */
static
directory_error_t
directory_provider_ad_lookup(
    directory_entry_rpc *pent,
    const char * const * attrs,
    int nattrs,
    const char *domain,
    const char *filter)
{
    adutils_ad_t *ad;
    adutils_rc batchrc;
    struct cbinfo cbinfo;
    adutils_query_state_t *qs;
    int rc;

    /*
     * NEEDSWORK:  Should eventually handle other forests.
     * NEEDSWORK:  Should eventually handle non-GC attributes.
     */
    ad = _idmapdstate.gcs[0];

    /* Stash away information for the callback function. */
    cbinfo.attrs = attrs;
    cbinfo.nattrs = nattrs;
    cbinfo.entry = pent;
    cbinfo.domain = domain;

    rc = adutils_lookup_batch_start(ad, 1, directory_provider_ad_cb,
        &cbinfo, &qs);
    if (rc != ADUTILS_SUCCESS) {
        return (directory_provider_ad_utils_error(
            "adutils_lookup_batch_start", rc));
    }

    rc = adutils_lookup_batch_add(qs, filter, attrs, domain,
        NULL, &batchrc);
    if (rc != ADUTILS_SUCCESS) {
        adutils_lookup_batch_release(&qs);
        return (directory_provider_ad_utils_error(
            "adutils_lookup_batch_add", rc));
    }

    rc = adutils_lookup_batch_end(&qs);
    if (rc != ADUTILS_SUCCESS) {
        return (directory_provider_ad_utils_error(
            "adutils_lookup_batch_end", rc));
    }

    if (batchrc != ADUTILS_SUCCESS) {
        /*
         * NEEDSWORK:  We're consistently getting -9997 here.
         * What does it mean?
         */
        return (NULL);
    }

    return (NULL);
}

/*
 * Callback from the LDAP functions when they get responses.
 * We don't really need (nor want) asynchronous handling, but it's
 * what libadutils gives us.
 */
static
void
directory_provider_ad_cb(
    LDAP *ld,
    LDAPMessage **ldapres,
    int rc,
    int qid,
    void *argp)
{
    NOTE(ARGUNUSED(rc, qid))
    struct cbinfo *cbinfo = (struct cbinfo *)argp;
    LDAPMessage *msg = *ldapres;

    for (msg = ldap_first_entry(ld, msg);
        msg != NULL;
        msg = ldap_next_entry(ld, msg)) {
        directory_provider_ad_cb1(ld, msg, cbinfo);
    }
}

/*
 * Process a single entry returned by an LDAP callback.
 * Note that this performs a function roughly equivalent to the
 * directory*Populate() functions in the other providers.
 * Given an LDAP response, populate the directory entry for return to
 * the caller.  This one differs primarily in that we're working directly
 * with LDAP, so we don't have to do any attribute translation.
 */
static
void
directory_provider_ad_cb1(
    LDAP *ld,
    LDAPMessage *msg,
    struct cbinfo *cbinfo)
{
    int nattrs = cbinfo->nattrs;
    const char * const *attrs = cbinfo->attrs;
    directory_entry_rpc *pent = cbinfo->entry;

    int i;
    directory_values_rpc *llvals;
    directory_error_t de;
    char *domain = NULL;

    /*
     * We don't have a way to filter for entries from the right domain
     * in the LDAP query, so we check for it here.  Searches based on
     * samAccountName might yield results from the wrong domain.
     */
    de = get_domain(ld, msg, &domain);
    if (de != NULL)
        goto err;

    if (cbinfo->domain != NULL && !domain_eq(cbinfo->domain, domain))
        goto out;

    /*
     * If we've already found a match, error.
     */
    if (pent->status != DIRECTORY_NOT_FOUND) {
        de = directory_error("Duplicate.AD",
            "Multiple matching entries found", NULL);
        goto err;
    }

    llvals = calloc(nattrs, sizeof (directory_values_rpc));
    if (llvals == NULL)
        goto nomem;

    pent->directory_entry_rpc_u.attrs.attrs_val = llvals;
    pent->directory_entry_rpc_u.attrs.attrs_len = nattrs;
    pent->status = DIRECTORY_FOUND;

    for (i = 0; i < nattrs; i++) {
        struct berval **bv;
        const char *a = attrs[i];
        directory_values_rpc *val = &llvals[i];

        bv = ldap_get_values_len(ld, msg, a);
#if defined(DUMP_VALUES)
        dump_bv_list(attrs[i], bv);
#endif
        if (bv != NULL) {
            de = bv_list_dav(val, bv);
            ldap_value_free_len(bv);
            if (de != NULL)
                goto err;
        } else if (uu_strcaseeq(a, "x-sun-canonicalName")) {
            bv = ldap_get_values_len(ld, msg, "sAMAccountName");
            if (bv != NULL) {
                int n = ldap_count_values_len(bv);
                if (n > 0) {
                    char *tmp;
                    (void) asprintf(&tmp, "%.*s@%s",
                        bv[0]->bv_len, bv[0]->bv_val,
                        domain);
                    if (tmp == NULL)
                        goto nomem;
                    const char *ctmp = tmp;
                    de = str_list_dav(val, &ctmp, 1);
                    free(tmp);
                    if (de != NULL)
                        goto err;
                }
            }
        } else if (uu_strcaseeq(a, "x-sun-provider")) {
            const char *provider = "LDAP-AD";
            de = str_list_dav(val, &provider, 1);
        }
    }

    goto out;

nomem:
    de = directory_error("ENOMEM.users",
        "No memory allocating return value for user lookup", NULL);

err:
    directory_entry_set_error(pent, de);
    de = NULL;

out:
    free(domain);
}

/*
 * Given a struct berval, populate a directory attribute value (which is a
 * list of values).
 * Note that here we populate the DAV with the exact bytes that LDAP returns.
 * Back over in the client it appends a \0 so that strings are null
 * terminated.
 */
static
directory_error_t
bv_list_dav(directory_values_rpc *lvals, struct berval **bv)
{
    directory_value_rpc *dav;
    int n;
    int i;

    n = ldap_count_values_len(bv);

    dav = calloc(n, sizeof (directory_value_rpc));
    if (dav == NULL)
        goto nomem;

    lvals->directory_values_rpc_u.values.values_val = dav;
    lvals->directory_values_rpc_u.values.values_len = n;
    lvals->found = TRUE;

    for (i = 0; i < n; i++) {
        dav[i].directory_value_rpc_val =
            uu_memdup(bv[i]->bv_val, bv[i]->bv_len);
        if (dav[i].directory_value_rpc_val == NULL)
            goto nomem;
        dav[i].directory_value_rpc_len = bv[i]->bv_len;
    }

    return (NULL);

nomem:
    return (directory_error("ENOMEM.bv_list_dav",
        "Insufficient memory copying values"));
}

#if defined(DUMP_VALUES)
static
void
dump_bv_list(const char *attr, struct berval **bv)
{
    int i;

    if (bv == NULL) {
        (void) fprintf(stderr, "%s:  (empty)\n", attr);
        return;
    }
    for (i = 0; bv[i] != NULL; i++) {
        (void) fprintf(stderr, "%s[%d] =\n", attr, i);
        dump(stderr, "    ", bv[i]->bv_val, bv[i]->bv_len);
    }
}
#endif  /* DUMP_VALUES */

/*
 * Return the domain associated with the specified entry.
 */
static
directory_error_t
get_domain(
    LDAP *ld,
    LDAPMessage *msg,
    char **domain)
{
    *domain = NULL;

    char *dn = ldap_get_dn(ld, msg);
    if (dn == NULL) {
        char buf[100];  /* big enough for any int */
        char *m;
        char *s;
        int err = ldap_get_lderrno(ld, &m, &s);
        (void) snprintf(buf, sizeof (buf), "%d", err);

        return directory_error("AD.get_domain.ldap_get_dn",
            "ldap_get_dn: %1 (%2)\n"
            "matched: %3\n"
            "error:   %4",
            ldap_err2string(err), buf,
            m == NULL ? "(null)" : m,
            s == NULL ? "(null)" : s,
            NULL);
    }

    *domain = adutils_dn2dns(dn);
    if (*domain == NULL) {
        directory_error_t de;

        de = directory_error("Unknown.get_domain.adutils_dn2dns",
            "get_domain:  Unexpected error from adutils_dn2dns(%1)",
            dn, NULL);
        free(dn);
        return (de);
    }
    free(dn);

    return (NULL);
}

/*
 * Given an error report from libadutils, generate a directory_error_t.
 */
static
directory_error_t
directory_provider_ad_utils_error(char *func, int rc)
{
    char rcstr[100];    /* plenty for any int */
    char code[100];     /* plenty for any int */
    (void) snprintf(rcstr, sizeof (rcstr), "%d", rc);
    (void) snprintf(code, sizeof (code), "ADUTILS.%d", rc);

    return (directory_error(code,
        "Error %2 from adutils function %1", func, rcstr, NULL));
}

struct directory_provider_static directory_provider_ad = {
    "AD",
    directory_provider_ad_get,
};