diff --git a/lib/common/acl.c b/lib/common/acl.c index 809a0b33bb..bd4e73346f 100644 --- a/lib/common/acl.c +++ b/lib/common/acl.c @@ -1,861 +1,864 @@ /* * Copyright 2004-2024 the Pacemaker project contributors * * The version control history for this file may have further details. * * This source code is licensed under the GNU Lesser General Public License * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY. */ #include #include #include #include #include #include #include #include #include #include #include #include "crmcommon_private.h" typedef struct xml_acl_s { enum xml_private_flags mode; gchar *xpath; } xml_acl_t; static void free_acl(void *data) { if (data) { xml_acl_t *acl = data; g_free(acl->xpath); free(acl); } } void pcmk__free_acls(GList *acls) { g_list_free_full(acls, free_acl); } static GList * create_acl(const xmlNode *xml, GList *acls, enum xml_private_flags mode) { xml_acl_t *acl = NULL; const char *tag = crm_element_value(xml, PCMK_XA_OBJECT_TYPE); const char *ref = crm_element_value(xml, PCMK_XA_REFERENCE); const char *xpath = crm_element_value(xml, PCMK_XA_XPATH); const char *attr = crm_element_value(xml, PCMK_XA_ATTRIBUTE); if ((tag == NULL) && (ref == NULL) && (xpath == NULL)) { // Schema should prevent this, but to be safe ... crm_trace("Ignoring ACL <%s> element without selection criteria", xml->name); return NULL; } acl = pcmk__assert_alloc(1, sizeof (xml_acl_t)); acl->mode = mode; if (xpath) { acl->xpath = g_strdup(xpath); crm_trace("Unpacked ACL <%s> element using xpath: %s", xml->name, acl->xpath); } else { GString *buf = g_string_sized_new(128); if ((ref != NULL) && (attr != NULL)) { // NOTE: schema currently does not allow this pcmk__g_strcat(buf, "//", pcmk__s(tag, "*"), "[@" PCMK_XA_ID "='", ref, "' and @", attr, "]", NULL); } else if (ref != NULL) { pcmk__g_strcat(buf, "//", pcmk__s(tag, "*"), "[@" PCMK_XA_ID "='", ref, "']", NULL); } else if (attr != NULL) { pcmk__g_strcat(buf, "//", pcmk__s(tag, "*"), "[@", attr, "]", NULL); } else { pcmk__g_strcat(buf, "//", pcmk__s(tag, "*"), NULL); } acl->xpath = buf->str; g_string_free(buf, FALSE); crm_trace("Unpacked ACL <%s> element as xpath: %s", xml->name, acl->xpath); } return g_list_append(acls, acl); } /*! * \internal * \brief Unpack a user, group, or role subtree of the ACLs section * * \param[in] acl_top XML of entire ACLs section * \param[in] acl_entry XML of ACL element being unpacked * \param[in,out] acls List of ACLs unpacked so far * * \return New head of (possibly modified) acls * * \note This function is recursive */ static GList * parse_acl_entry(const xmlNode *acl_top, const xmlNode *acl_entry, GList *acls) { for (const xmlNode *child = pcmk__xe_first_child(acl_entry, NULL, NULL, NULL); child != NULL; child = pcmk__xe_next(child)) { if (pcmk__xe_is(child, PCMK_XE_ACL_PERMISSION)) { const char *kind = crm_element_value(child, PCMK_XA_KIND); pcmk__assert(kind != NULL); crm_trace("Unpacking <" PCMK_XE_ACL_PERMISSION "> element of " "kind '%s'", kind); if (pcmk__str_eq(kind, PCMK_VALUE_READ, pcmk__str_none)) { acls = create_acl(child, acls, pcmk__xf_acl_read); } else if (pcmk__str_eq(kind, PCMK_VALUE_WRITE, pcmk__str_none)) { acls = create_acl(child, acls, pcmk__xf_acl_write); } else if (pcmk__str_eq(kind, PCMK_VALUE_DENY, pcmk__str_none)) { acls = create_acl(child, acls, pcmk__xf_acl_deny); } else { crm_warn("Ignoring unknown ACL kind '%s'", kind); } } else if (pcmk__xe_is(child, PCMK_XE_ROLE)) { const char *ref_role = crm_element_value(child, PCMK_XA_ID); crm_trace("Unpacking <" PCMK_XE_ROLE "> element"); if (ref_role == NULL) { continue; } for (xmlNode *role = pcmk__xe_first_child(acl_top, NULL, NULL, NULL); role != NULL; role = pcmk__xe_next(role)) { const char *role_id = NULL; if (!pcmk__xe_is(role, PCMK_XE_ACL_ROLE)) { continue; } role_id = crm_element_value(role, PCMK_XA_ID); if (pcmk__str_eq(ref_role, role_id, pcmk__str_none)) { crm_trace("Unpacking referenced role '%s' in <%s> element", role_id, acl_entry->name); acls = parse_acl_entry(acl_top, role, acls); break; } } } } return acls; } /* */ static const char * acl_to_text(enum xml_private_flags flags) { if (pcmk_is_set(flags, pcmk__xf_acl_deny)) { return "deny"; } else if (pcmk_any_flags_set(flags, pcmk__xf_acl_write|pcmk__xf_acl_create)) { return "read/write"; } else if (pcmk_is_set(flags, pcmk__xf_acl_read)) { return "read"; } return "none"; } void pcmk__apply_acl(xmlNode *xml) { GList *aIter = NULL; xml_doc_private_t *docpriv = xml->doc->_private; xml_node_private_t *nodepriv; xmlXPathObjectPtr xpathObj = NULL; if (!xml_acl_enabled(xml)) { crm_trace("Skipping ACLs for user '%s' because not enabled for this XML", docpriv->user); return; } for (aIter = docpriv->acls; aIter != NULL; aIter = aIter->next) { int max = 0, lpc = 0; xml_acl_t *acl = aIter->data; xpathObj = xpath_search(xml, acl->xpath); max = numXpathResults(xpathObj); for (lpc = 0; lpc < max; lpc++) { xmlNode *match = getXpathResult(xpathObj, lpc); nodepriv = match->_private; pcmk__set_xml_flags(nodepriv, acl->mode); // Build a GString only if tracing is enabled pcmk__if_tracing( { GString *path = pcmk__element_xpath(match); crm_trace("Applying %s ACL to %s matched by %s", acl_to_text(acl->mode), path->str, acl->xpath); g_string_free(path, TRUE); }, {} ); } crm_trace("Applied %s ACL %s (%d match%s)", acl_to_text(acl->mode), acl->xpath, max, ((max == 1)? "" : "es")); freeXpathObject(xpathObj); } } /*! * \internal * \brief Unpack ACLs for a given user into the * metadata of the target XML tree * * Taking the description of ACLs from the source XML tree and * marking up the target XML tree with access information for the * given user by tacking it onto the relevant nodes * * \param[in] source XML with ACL definitions * \param[in,out] target XML that ACLs will be applied to * \param[in] user Username whose ACLs need to be unpacked */ void pcmk__unpack_acl(xmlNode *source, xmlNode *target, const char *user) { xml_doc_private_t *docpriv = NULL; if ((target == NULL) || (target->doc == NULL) || (target->doc->_private == NULL)) { return; } docpriv = target->doc->_private; if (!pcmk_acl_required(user)) { crm_trace("Not unpacking ACLs because not required for user '%s'", user); } else if (docpriv->acls == NULL) { xmlNode *acls = get_xpath_object("//" PCMK_XE_ACLS, source, LOG_NEVER); pcmk__str_update(&docpriv->user, user); if (acls) { xmlNode *child = NULL; for (child = pcmk__xe_first_child(acls, NULL, NULL, NULL); child != NULL; child = pcmk__xe_next(child)) { if (pcmk__xe_is(child, PCMK_XE_ACL_TARGET)) { const char *id = crm_element_value(child, PCMK_XA_NAME); if (id == NULL) { id = crm_element_value(child, PCMK_XA_ID); } if (id && strcmp(id, user) == 0) { crm_debug("Unpacking ACLs for user '%s'", id); docpriv->acls = parse_acl_entry(acls, child, docpriv->acls); } } else if (pcmk__xe_is(child, PCMK_XE_ACL_GROUP)) { const char *id = crm_element_value(child, PCMK_XA_NAME); if (id == NULL) { id = crm_element_value(child, PCMK_XA_ID); } if (id && pcmk__is_user_in_group(user,id)) { crm_debug("Unpacking ACLs for group '%s'", id); docpriv->acls = parse_acl_entry(acls, child, docpriv->acls); } } } } } } /*! * \internal * \brief Copy source to target and set xf_acl_enabled flag in target * * \param[in] acl_source XML with ACL definitions * \param[in,out] target XML that ACLs will be applied to * \param[in] user Username whose ACLs need to be set */ void pcmk__enable_acl(xmlNode *acl_source, xmlNode *target, const char *user) { pcmk__unpack_acl(acl_source, target, user); pcmk__set_xml_doc_flag(target, pcmk__xf_acl_enabled); pcmk__apply_acl(target); } static inline bool test_acl_mode(enum xml_private_flags allowed, enum xml_private_flags requested) { if (pcmk_is_set(allowed, pcmk__xf_acl_deny)) { return false; } else if (pcmk_all_flags_set(allowed, requested)) { return true; } else if (pcmk_is_set(requested, pcmk__xf_acl_read) && pcmk_is_set(allowed, pcmk__xf_acl_write)) { return true; } else if (pcmk_is_set(requested, pcmk__xf_acl_create) && pcmk_any_flags_set(allowed, pcmk__xf_acl_write|pcmk__xf_created)) { return true; } return false; } /*! * \internal * \brief Rid XML tree of all unreadable nodes and node properties * * \param[in,out] xml Root XML node to be purged of attributes * * \return true if this node or any of its children are readable * if false is returned, xml will be freed * * \note This function is recursive */ static bool purge_xml_attributes(xmlNode *xml) { xmlNode *child = NULL; xmlAttr *xIter = NULL; bool readable_children = false; xml_node_private_t *nodepriv = xml->_private; if (test_acl_mode(nodepriv->flags, pcmk__xf_acl_read)) { crm_trace("%s[@" PCMK_XA_ID "=%s] is readable", xml->name, pcmk__xe_id(xml)); return true; } xIter = xml->properties; while (xIter != NULL) { xmlAttr *tmp = xIter; const char *prop_name = (const char *)xIter->name; xIter = xIter->next; if (strcmp(prop_name, PCMK_XA_ID) == 0) { continue; } pcmk__xa_remove(tmp, true); } child = pcmk__xml_first_child(xml); while ( child != NULL ) { xmlNode *tmp = child; child = pcmk__xml_next(child); readable_children |= purge_xml_attributes(tmp); } if (!readable_children) { // Nothing readable under here, so purge completely pcmk__xml_free(xml); } return readable_children; } /*! * \brief Copy ACL-allowed portions of specified XML * * \param[in] user Username whose ACLs should be used * \param[in] acl_source XML containing ACLs * \param[in] xml XML to be copied * \param[out] result Copy of XML portions readable via ACLs * * \return true if xml exists and ACLs are required for user, false otherwise * \note If this returns true, caller should use \p result rather than \p xml */ bool xml_acl_filtered_copy(const char *user, xmlNode *acl_source, xmlNode *xml, xmlNode **result) { GList *aIter = NULL; xmlNode *target = NULL; xml_doc_private_t *docpriv = NULL; *result = NULL; if ((xml == NULL) || !pcmk_acl_required(user)) { crm_trace("Not filtering XML because ACLs not required for user '%s'", user); return false; } crm_trace("Filtering XML copy using user '%s' ACLs", user); target = pcmk__xml_copy(NULL, xml); if (target == NULL) { return true; } pcmk__enable_acl(acl_source, target, user); docpriv = target->doc->_private; for(aIter = docpriv->acls; aIter != NULL && target; aIter = aIter->next) { int max = 0; xml_acl_t *acl = aIter->data; if (acl->mode != pcmk__xf_acl_deny) { /* Nothing to do */ } else if (acl->xpath) { int lpc = 0; xmlXPathObjectPtr xpathObj = xpath_search(target, acl->xpath); max = numXpathResults(xpathObj); for(lpc = 0; lpc < max; lpc++) { xmlNode *match = getXpathResult(xpathObj, lpc); if (!purge_xml_attributes(match) && (match == target)) { crm_trace("ACLs deny user '%s' access to entire XML document", user); freeXpathObject(xpathObj); return true; } } crm_trace("ACLs deny user '%s' access to %s (%d %s)", user, acl->xpath, max, pcmk__plural_alt(max, "match", "matches")); freeXpathObject(xpathObj); } } if (!purge_xml_attributes(target)) { crm_trace("ACLs deny user '%s' access to entire XML document", user); return true; } if (docpriv->acls) { g_list_free_full(docpriv->acls, free_acl); docpriv->acls = NULL; } else { crm_trace("User '%s' without ACLs denied access to entire XML document", user); pcmk__xml_free(target); target = NULL; } if (target) { *result = target; } return true; } /*! * \internal * \brief Check whether creation of an XML element is implicitly allowed * * Check whether XML is a "scaffolding" element whose creation is implicitly * allowed regardless of ACLs (that is, it is not in the ACL section and has * no attributes other than \c PCMK_XA_ID). * * \param[in] xml XML element to check * * \return true if XML element is implicitly allowed, false otherwise */ static bool implicitly_allowed(const xmlNode *xml) { GString *path = NULL; for (xmlAttr *prop = xml->properties; prop != NULL; prop = prop->next) { if (strcmp((const char *) prop->name, PCMK_XA_ID) != 0) { return false; } } path = pcmk__element_xpath(xml); pcmk__assert(path != NULL); if (strstr((const char *) path->str, "/" PCMK_XE_ACLS "/") != NULL) { g_string_free(path, TRUE); return false; } g_string_free(path, TRUE); return true; } #define display_id(xml) pcmk__s(pcmk__xe_id(xml), "") /*! * \internal * \brief Drop XML nodes created in violation of ACLs * * Given an XML element, free all of its descendant nodes created in violation * of ACLs, with the exception of allowing "scaffolding" elements (i.e. those * that aren't in the ACL section and don't have any attributes other than * \c PCMK_XA_ID). * * \param[in,out] xml XML to check * \param[in] check_top Whether to apply checks to argument itself * (if true, xml might get freed) * * \note This function is recursive */ void pcmk__apply_creation_acl(xmlNode *xml, bool check_top) { xml_node_private_t *nodepriv = xml->_private; if (pcmk_is_set(nodepriv->flags, pcmk__xf_created)) { if (implicitly_allowed(xml)) { crm_trace("Creation of <%s> scaffolding with " PCMK_XA_ID "=\"%s\"" " is implicitly allowed", xml->name, display_id(xml)); } else if (pcmk__check_acl(xml, NULL, pcmk__xf_acl_write)) { crm_trace("ACLs allow creation of <%s> with " PCMK_XA_ID "=\"%s\"", xml->name, display_id(xml)); } else if (check_top) { /* is_root=true should be impossible with check_top=true, but check * for sanity */ bool is_root = (xmlDocGetRootElement(xml->doc) == xml); xml_doc_private_t *docpriv = xml->doc->_private; crm_trace("ACLs disallow creation of %s<%s> with " PCMK_XA_ID "=\"%s\"", (is_root? "root element " : ""), xml->name, display_id(xml)); // pcmk__xml_free() checks ACLs if enabled, which would fail pcmk__clear_xml_flags(docpriv, pcmk__xf_acl_enabled); pcmk__xml_free(xml); if (!is_root) { // If root, the document was freed. Otherwise re-enable ACLs. pcmk__set_xml_flags(docpriv, pcmk__xf_acl_enabled); } return; } else { crm_notice("ACLs would disallow creation of %s<%s> with " PCMK_XA_ID "=\"%s\"", ((xml == xmlDocGetRootElement(xml->doc))? "root element " : ""), xml->name, display_id(xml)); } } for (xmlNode *cIter = pcmk__xml_first_child(xml); cIter != NULL; ) { xmlNode *child = cIter; cIter = pcmk__xml_next(cIter); /* In case it is free'd */ pcmk__apply_creation_acl(child, true); } } /*! * \brief Check whether or not an XML node is ACL-denied * * \param[in] xml node to check * * \return true if XML node exists and is ACL-denied, false otherwise */ bool xml_acl_denied(const xmlNode *xml) { if (xml && xml->doc && xml->doc->_private){ xml_doc_private_t *docpriv = xml->doc->_private; return pcmk_is_set(docpriv->flags, pcmk__xf_acl_denied); } return false; } void xml_acl_disable(xmlNode *xml) { if (xml_acl_enabled(xml)) { xml_doc_private_t *docpriv = xml->doc->_private; /* Catch anything that was created but shouldn't have been */ pcmk__apply_acl(xml); pcmk__apply_creation_acl(xml, false); pcmk__clear_xml_flags(docpriv, pcmk__xf_acl_enabled); } } /*! * \brief Check whether or not an XML node is ACL-enabled * * \param[in] xml node to check * * \return true if XML node exists and is ACL-enabled, false otherwise */ bool xml_acl_enabled(const xmlNode *xml) { if (xml && xml->doc && xml->doc->_private){ xml_doc_private_t *docpriv = xml->doc->_private; return pcmk_is_set(docpriv->flags, pcmk__xf_acl_enabled); } return false; } bool pcmk__check_acl(xmlNode *xml, const char *name, enum xml_private_flags mode) { pcmk__assert((xml != NULL) && (xml->doc != NULL) && (xml->doc->_private != NULL)); if (pcmk__tracking_xml_changes(xml, false) && xml_acl_enabled(xml)) { xmlNode *parent = xml; xml_doc_private_t *docpriv = xml->doc->_private; GString *xpath = NULL; if (docpriv->acls == NULL) { pcmk__set_xml_doc_flag(xml, pcmk__xf_acl_denied); pcmk__if_tracing({}, return false); xpath = pcmk__element_xpath(xml); if (name != NULL) { pcmk__g_strcat(xpath, "[@", name, "]", NULL); } qb_log_from_external_source(__func__, __FILE__, "User '%s' without ACLs denied %s " "access to %s", LOG_TRACE, __LINE__, 0, docpriv->user, acl_to_text(mode), (const char *) xpath->str); g_string_free(xpath, TRUE); return false; } /* Walk the tree upwards looking for xml_acl_* flags * - Creating an attribute requires write permissions for the node * - Creating a child requires write permissions for the parent */ if (name) { xmlAttr *attr = xmlHasProp(xml, (pcmkXmlStr) name); if (attr && mode == pcmk__xf_acl_create) { mode = pcmk__xf_acl_write; } } while (parent && parent->_private) { xml_node_private_t *nodepriv = parent->_private; if (test_acl_mode(nodepriv->flags, mode)) { return true; } else if (pcmk_is_set(nodepriv->flags, pcmk__xf_acl_deny)) { pcmk__set_xml_doc_flag(xml, pcmk__xf_acl_denied); pcmk__if_tracing({}, return false); xpath = pcmk__element_xpath(xml); if (name != NULL) { pcmk__g_strcat(xpath, "[@", name, "]", NULL); } qb_log_from_external_source(__func__, __FILE__, "%sACL denies user '%s' %s access " "to %s", LOG_TRACE, __LINE__, 0, (parent != xml)? "Parent ": "", docpriv->user, acl_to_text(mode), (const char *) xpath->str); g_string_free(xpath, TRUE); return false; } parent = parent->parent; } pcmk__set_xml_doc_flag(xml, pcmk__xf_acl_denied); pcmk__if_tracing({}, return false); xpath = pcmk__element_xpath(xml); if (name != NULL) { pcmk__g_strcat(xpath, "[@", name, "]", NULL); } qb_log_from_external_source(__func__, __FILE__, "Default ACL denies user '%s' %s access to " "%s", LOG_TRACE, __LINE__, 0, docpriv->user, acl_to_text(mode), (const char *) xpath->str); g_string_free(xpath, TRUE); return false; } return true; } /*! * \brief Check whether ACLs are required for a given user * * \param[in] User name to check * * \return true if the user requires ACLs, false otherwise */ bool pcmk_acl_required(const char *user) { if (pcmk__str_empty(user)) { crm_trace("ACLs not required because no user set"); return false; } else if (!strcmp(user, CRM_DAEMON_USER) || !strcmp(user, "root")) { crm_trace("ACLs not required for privileged user %s", user); return false; } crm_trace("ACLs required for %s", user); return true; } char * pcmk__uid2username(uid_t uid) { struct passwd *pwent = getpwuid(uid); if (pwent == NULL) { crm_perror(LOG_INFO, "Cannot get user details for user ID %d", uid); return NULL; } return pcmk__str_copy(pwent->pw_name); } /*! * \internal * \brief Set the ACL user field properly on an XML request * * Multiple user names are potentially involved in an XML request: the effective * user of the current process; the user name known from an IPC client * connection; and the user name obtained from the request itself, whether by * the current standard XML attribute name or an older legacy attribute name. * This function chooses the appropriate one that should be used for ACLs, sets * it in the request (using the standard attribute name, and the legacy name if * given), and returns it. * * \param[in,out] request XML request to update * \param[in] field Alternate name for ACL user name XML attribute * \param[in] peer_user User name as known from IPC connection * * \return ACL user name actually used */ const char * pcmk__update_acl_user(xmlNode *request, const char *field, const char *peer_user) { static const char *effective_user = NULL; const char *requested_user = NULL; const char *user = NULL; if (effective_user == NULL) { effective_user = pcmk__uid2username(geteuid()); if (effective_user == NULL) { effective_user = pcmk__str_copy("#unprivileged"); crm_err("Unable to determine effective user, assuming unprivileged for ACLs"); } } requested_user = crm_element_value(request, PCMK__XA_ACL_TARGET); if (requested_user == NULL) { - /* @COMPAT rolling upgrades <=1.1.11 + /* Currently, different XML attribute names are used for the ACL user in + * different contexts (PCMK__XA_ATTR_USER, PCMK__XA_CIB_USER, etc.). + * The caller may specify that name as the field argument. * - * field is checked for backward compatibility with older versions that - * did not use PCMK__XA_ACL_TARGET. + * @TODO Standardize on PCMK__XA_ACL_TARGET and eventually drop the + * others once rolling upgrades from versions older than that are no + * longer supported. */ requested_user = crm_element_value(request, field); } if (!pcmk__is_privileged(effective_user)) { /* We're not running as a privileged user, set or overwrite any existing * value for PCMK__XA_ACL_TARGET */ user = effective_user; } else if (peer_user == NULL && requested_user == NULL) { /* No user known or requested, use 'effective_user' and make sure one is * set for the request */ user = effective_user; } else if (peer_user == NULL) { /* No user known, trusting 'requested_user' */ user = requested_user; } else if (!pcmk__is_privileged(peer_user)) { /* The peer is not a privileged user, set or overwrite any existing * value for PCMK__XA_ACL_TARGET */ user = peer_user; } else if (requested_user == NULL) { /* Even if we're privileged, make sure there is always a value set */ user = peer_user; } else { /* Legal delegation to 'requested_user' */ user = requested_user; } // This requires pointer comparison, not string comparison if (user != crm_element_value(request, PCMK__XA_ACL_TARGET)) { crm_xml_add(request, PCMK__XA_ACL_TARGET, user); } if (field != NULL && user != crm_element_value(request, field)) { crm_xml_add(request, field, user); } return requested_user; }