From 370dd812529ad7a2843127c89da5543633ab5c2a Mon Sep 17 00:00:00 2001 From: Sumit Bose Date: Fri, 22 Jan 2016 18:14:45 +0100 Subject: [PATCH] sdap: improve filtering of multiple results in GC lookups The Global Catalog of AD contains some information about all users and groups in an AD forest. Users from different domain in the forest can have the same name. The most obvious example is the Administrator user which is present in all domains. Although SSSD uses a domain specific search base for looking up users in the GC the search might still return multiple results if there is a user with the same name in one of the child (or grand-child ...) domains because of the hierarchic nature of the LDAP tree. Limiting the search depth would not help because users can be created in deeply nested OUs. Currently SSSD expects in this case that the user object is store in CN=Users or below. This works for all default users like Administrator but in general users can be created anywhere in the directory tree. If a user is created outside of CN=Users and there is a user with the same name in a child domain the initgroups command to look up the group-memberships of the user fails because it is not clear which of the two results should be used (initgroups for the child domain user works fine). This patch adds an additional scheme to select the right result based on the domain component attribute name 'dc'. This attribute indicates an additional component in the domain name and hence a child domain. So as long as the result contains a dc component following out search base it cannot be the object we are looking for. This scheme includes the old CN=Users based one but since it is more expensive I kept the old scheme which so far worked all the time and only use the new one if the old one fails. Resolves https://fedorahosted.org/sssd/ticket/2961 --- src/db/sysdb.h | 6 ++ src/db/sysdb_subdomains.c | 153 +++++++++++++++++++++++++++++ src/providers/ldap/sdap_async_initgroups.c | 46 ++------- src/tests/cmocka/test_sysdb_subdomains.c | 73 ++++++++++++++ 4 files changed, 238 insertions(+), 40 deletions(-) diff --git a/src/db/sysdb.h b/src/db/sysdb.h index 2e797fd7fa39163c2ab6a10e51228e0f1af3f9e3..a2fa733f23f454a57410710dc90385675c88fe43 100644 --- a/src/db/sysdb.h +++ b/src/db/sysdb.h @@ -1226,4 +1226,10 @@ errno_t sysdb_handle_original_uuid(const char *orig_name, const char *src_name, struct sysdb_attrs *dest_attrs, const char *dest_name); + +errno_t try_to_find_expected_dn(struct sss_domain_info *dom, + const char *domain_component_name, + struct sysdb_attrs **usr_attrs, + size_t count, + struct sysdb_attrs **exp_usr); #endif /* __SYS_DB_H__ */ diff --git a/src/db/sysdb_subdomains.c b/src/db/sysdb_subdomains.c index b2bf1a0742171b7beccb44fa915c8adba51fefa3..f9b13cb3e6e36d1df731a864a19c36b042e9e7fa 100644 --- a/src/db/sysdb_subdomains.c +++ b/src/db/sysdb_subdomains.c @@ -1049,3 +1049,156 @@ done: talloc_free(tmp_ctx); return ret; } + +errno_t try_to_find_expected_dn(struct sss_domain_info *dom, + const char *domain_component_name, + struct sysdb_attrs **usr_attrs, + size_t count, + struct sysdb_attrs **exp_usr) +{ + char *dom_basedn; + size_t dom_basedn_len; + char *expected_basedn; + size_t expected_basedn_len; + size_t dn_len; + const char *orig_dn; + size_t c = 0; + int ret; + TALLOC_CTX *tmp_ctx; + struct ldb_context *ldb_ctx; + struct ldb_dn *ldb_dom_basedn; + int dom_basedn_comp_num; + struct ldb_dn *ldb_dn; + int dn_comp_num; + const char *component_name; + struct sysdb_attrs *result = NULL; + const char *result_dn_str; + + if (dom == NULL || domain_component_name == NULL || usr_attrs == NULL + || count == 0) { + return EINVAL; + } + + tmp_ctx = talloc_new(NULL); + if (tmp_ctx == NULL) { + DEBUG(SSSDBG_OP_FAILURE, "talloc_new failed.\n"); + return ENOMEM; + } + + ret = domain_to_basedn(tmp_ctx, dom->name, &dom_basedn); + if (ret != EOK) { + DEBUG(SSSDBG_OP_FAILURE, "domain_to_basedn failed.\n"); + goto done; + } + expected_basedn = talloc_asprintf(tmp_ctx, "%s%s", "cn=users,", dom_basedn); + if (expected_basedn == NULL) { + ret = ENOMEM; + goto done; + } + + ldb_ctx = sysdb_ctx_get_ldb(dom->sysdb); + if (ldb_ctx == NULL) { + DEBUG(SSSDBG_OP_FAILURE, "Missing ldb context.\n"); + ret = EINVAL; + goto done; + } + + ldb_dom_basedn = ldb_dn_new(tmp_ctx, ldb_ctx, dom_basedn); + if (ldb_dom_basedn == NULL) { + DEBUG(SSSDBG_OP_FAILURE, "ldb_dn_new failed.\n"); + ret = ENOMEM; + goto done; + } + + dom_basedn_comp_num = ldb_dn_get_comp_num(ldb_dom_basedn); + dom_basedn_comp_num++; + + DEBUG(SSSDBG_TRACE_ALL, "Expected BaseDN is [%s].\n", expected_basedn); + expected_basedn_len = strlen(expected_basedn); + dom_basedn_len = strlen(dom_basedn); + + for (c = 0; c < count; c++) { + ret = sysdb_attrs_get_string(usr_attrs[c], SYSDB_ORIG_DN, &orig_dn); + if (ret != EOK) { + DEBUG(SSSDBG_OP_FAILURE, "sysdb_attrs_get_string failed.\n"); + goto done; + } + dn_len = strlen(orig_dn); + + if (dn_len > expected_basedn_len + && strcasecmp(orig_dn + (dn_len - expected_basedn_len), + expected_basedn) == 0) { + DEBUG(SSSDBG_TRACE_ALL, + "Found matching dn [%s].\n", orig_dn); + if (result != NULL) { + DEBUG(SSSDBG_OP_FAILURE, + "Found 2 matching DN [%s] and [%s], expecting only 1.\n", + result_dn_str, orig_dn); + ret = EINVAL; + goto done; + } + result = usr_attrs[c]; + result_dn_str = orig_dn; + } + } + + if (result == NULL) { + for (c = 0; c < count; c++) { + ret = sysdb_attrs_get_string(usr_attrs[c], SYSDB_ORIG_DN, &orig_dn); + if (ret != EOK) { + DEBUG(SSSDBG_OP_FAILURE, "sysdb_attrs_get_string failed.\n"); + goto done; + } + dn_len = strlen(orig_dn); + + if (dn_len > dom_basedn_len + && strcasecmp(orig_dn + (dn_len - dom_basedn_len), + dom_basedn) == 0) { + ldb_dn = ldb_dn_new(tmp_ctx, ldb_ctx, orig_dn); + if (ldb_dn == NULL) { + DEBUG(SSSDBG_OP_FAILURE, "ldb_dn_new failed"); + ret = ENOMEM; + goto done; + } + + dn_comp_num = ldb_dn_get_comp_num(ldb_dn); + if (dn_comp_num > dom_basedn_comp_num) { + component_name = ldb_dn_get_component_name(ldb_dn, + (dn_comp_num - dom_basedn_comp_num)); + DEBUG(SSSDBG_TRACE_ALL, "Comparing [%s] and [%s].\n", + component_name, + domain_component_name); + if (component_name != NULL + && strcasecmp(component_name, + domain_component_name) != 0) { + DEBUG(SSSDBG_TRACE_ALL, + "Found matching dn [%s].\n", orig_dn); + if (result != NULL) { + DEBUG(SSSDBG_OP_FAILURE, + "Found 2 matching DN [%s] and [%s], " + "expecting only 1.\n", result_dn_str, orig_dn); + ret = EINVAL; + goto done; + } + result = usr_attrs[c]; + result_dn_str = orig_dn; + } + } + } + } + } + + if (result == NULL) { + DEBUG(SSSDBG_OP_FAILURE, "No matching DN found.\n"); + ret = ENOENT; + goto done; + } + + *exp_usr = result; + + ret = EOK; +done: + talloc_free(tmp_ctx); + + return ret; +} diff --git a/src/providers/ldap/sdap_async_initgroups.c b/src/providers/ldap/sdap_async_initgroups.c index 39b310a4e2f6b4a0cef79b9c32f6e286e57ffde0..1f5689a4a680bcb620ecb15dbd2d5c00142fa888 100644 --- a/src/providers/ldap/sdap_async_initgroups.c +++ b/src/providers/ldap/sdap_async_initgroups.c @@ -2832,8 +2832,6 @@ static void sdap_get_initgr_user(struct tevent_req *subreq) const char *orig_dn; const char *cname; bool in_transaction = false; - char *expected_basedn; - size_t expected_basedn_len; size_t dn_len; size_t c = 0; @@ -2871,54 +2869,22 @@ static void sdap_get_initgr_user(struct tevent_req *subreq) tevent_req_error(req, ret); return; } + } else if (count == 1) { + state->orig_user = usr_attrs[0]; } else if (count != 1) { DEBUG(SSSDBG_OP_FAILURE, "Expected one user entry and got %zu\n", count); - ret = domain_to_basedn(state, state->dom->name, &expected_basedn); + ret = try_to_find_expected_dn(state->dom, "dc", usr_attrs, count, + &state->orig_user); if (ret != EOK) { - DEBUG(SSSDBG_OP_FAILURE, "domain_to_basedn failed.\n"); - tevent_req_error(req, ret); - return; - } - expected_basedn = talloc_asprintf(state, "%s%s", - "cn=users,", expected_basedn); - if (expected_basedn == NULL) { - DEBUG(SSSDBG_OP_FAILURE, "talloc_append failed.\n"); - tevent_req_error(req, ENOMEM); - return; - } - - DEBUG(SSSDBG_TRACE_ALL, "Expected BaseDN is [%s].\n", expected_basedn); - expected_basedn_len = strlen(expected_basedn); - - for (c = 0; c < count; c++) { - ret = sysdb_attrs_get_string(usr_attrs[c], SYSDB_ORIG_DN, &orig_dn); - if (ret != EOK) { - DEBUG(SSSDBG_OP_FAILURE, "sysdb_attrs_get_string failed.\n"); - tevent_req_error(req, ret); - return; - } - dn_len = strlen(orig_dn); - - if (dn_len > expected_basedn_len - && strcasecmp(orig_dn + (dn_len - expected_basedn_len), - expected_basedn) == 0) { - DEBUG(SSSDBG_TRACE_ALL, - "Found matching dn [%s].\n", orig_dn); - break; - } - } - - if (c == count) { - DEBUG(SSSDBG_OP_FAILURE, "No matching DN found.\n"); + DEBUG(SSSDBG_OP_FAILURE, + "try_to_find_expected_dn failed. No matching DN found.\n"); tevent_req_error(req, EINVAL); return; } } - state->orig_user = usr_attrs[c]; - ret = sysdb_transaction_start(state->sysdb); if (ret) { DEBUG(SSSDBG_CRIT_FAILURE, "Failed to start transaction\n"); diff --git a/src/tests/cmocka/test_sysdb_subdomains.c b/src/tests/cmocka/test_sysdb_subdomains.c index 701bfb726ff7e950d4439b3dc1a3bee437c9e7ed..dd3e81a8b1857ffe014ecee9d104fafc56afa8be 100644 --- a/src/tests/cmocka/test_sysdb_subdomains.c +++ b/src/tests/cmocka/test_sysdb_subdomains.c @@ -509,6 +509,76 @@ static void test_sysdb_link_ad_multidom(void **state) } +static void test_try_to_find_expected_dn(void **state) +{ + int ret; + struct sysdb_attrs *result; + struct sysdb_attrs *usr_attrs[10] = { NULL }; + struct sss_domain_info *dom; + struct subdom_test_ctx *test_ctx = + talloc_get_type(*state, struct subdom_test_ctx); + + dom = find_domain_by_name(test_ctx->tctx->dom, + "child2.test_sysdb_subdomains_2", true); + assert_non_null(dom); + + usr_attrs[0] = sysdb_new_attrs(test_ctx); + assert_non_null(usr_attrs[0]); + + ret = sysdb_attrs_add_string(usr_attrs[0], SYSDB_ORIG_DN, + "uid=user,cn=abc,dc=c2,dc=child2,dc=test_sysdb_subdomains_2"); + assert_int_equal(ret, EOK); + + ret = try_to_find_expected_dn(NULL, NULL, NULL, 0, NULL); + assert_int_equal(ret, EINVAL); + + ret = try_to_find_expected_dn(dom, "dc", usr_attrs, 1, &result); + assert_int_equal(ret, ENOENT); + + ret = try_to_find_expected_dn(dom, "xy", usr_attrs, 1, &result); + assert_int_equal(ret, EOK); + assert_ptr_equal(result, usr_attrs[0]); + + usr_attrs[1] = sysdb_new_attrs(test_ctx); + assert_non_null(usr_attrs[1]); + + ret = sysdb_attrs_add_string(usr_attrs[1], SYSDB_ORIG_DN, + "uid=user1,cn=abc,dc=child2,dc=test_sysdb_subdomains_2"); + assert_int_equal(ret, EOK); + + usr_attrs[2] = sysdb_new_attrs(test_ctx); + assert_non_null(usr_attrs[2]); + + ret = sysdb_attrs_add_string(usr_attrs[2], SYSDB_ORIG_DN, + "uid=user2,cn=abc,dc=c2,dc=child2,dc=test_sysdb_subdomains_2"); + assert_int_equal(ret, EOK); + + ret = try_to_find_expected_dn(dom, "dc", usr_attrs, 3, &result); + assert_int_equal(ret, EOK); + assert_ptr_equal(result, usr_attrs[1]); + + ret = try_to_find_expected_dn(dom, "xy", usr_attrs, 3, &result); + assert_int_equal(ret, EINVAL); + + /* Make sure cn=users match is preferred */ + talloc_free(usr_attrs[2]); + usr_attrs[2] = sysdb_new_attrs(test_ctx); + assert_non_null(usr_attrs[2]); + + ret = sysdb_attrs_add_string(usr_attrs[2], SYSDB_ORIG_DN, + "uid=user2,cn=abc,cn=users,dc=child2,dc=test_sysdb_subdomains_2"); + assert_int_equal(ret, EOK); + + ret = try_to_find_expected_dn(dom, "dc", usr_attrs, 3, &result); + assert_int_equal(ret, EOK); + assert_ptr_equal(result, usr_attrs[2]); + + + talloc_free(usr_attrs[0]); + talloc_free(usr_attrs[1]); + talloc_free(usr_attrs[2]); +} + int main(int argc, const char *argv[]) { int rv; @@ -542,6 +612,9 @@ int main(int argc, const char *argv[]) cmocka_unit_test_setup_teardown(test_sysdb_link_ad_multidom, test_sysdb_subdom_setup, test_sysdb_subdom_teardown), + cmocka_unit_test_setup_teardown(test_try_to_find_expected_dn, + test_sysdb_subdom_setup, + test_sysdb_subdom_teardown), }; /* Set debug level to invalid value so we can deside if -d 0 was used. */ -- 2.1.0