From 512673924267695739dc98090b892cf2593d2ab6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pavel=20B=C5=99ezina?= Date: Wed, 20 Mar 2013 14:53:29 +0100 Subject: [PATCH 5/6] DNS sites support - replace SRV lookup code with a plugin call https://fedorahosted.org/sssd/ticket/1032 Removes hard coded SRV lookup code with a plugin call. This patch breaks SRV lookups as there is currently no plugin in use. It is fixed in next patch. --- src/providers/fail_over.c | 370 ++++++++++++++-------------------------------- 1 file changed, 112 insertions(+), 258 deletions(-) diff --git a/src/providers/fail_over.c b/src/providers/fail_over.c index 660fe8261aa279735af2b8d9d31596acbad19810..a02dc9a41a60a155cb7016b56318a22dca87d4f9 100644 --- a/src/providers/fail_over.c +++ b/src/providers/fail_over.c @@ -215,21 +215,6 @@ int fo_is_srv_lookup(struct fo_server *s) return s && s->srv_data; } -static char * -get_srv_query(TALLOC_CTX *mem_ctx, struct fo_server *server) -{ - char *query; - - if (!fo_is_srv_lookup(server)) { - return NULL; - } - - query = talloc_asprintf(mem_ctx, "_%s._%s.%s", server->srv_data->srv, - server->srv_data->proto, - server->srv_data->dns_domain); - return query; -} - static struct fo_server * collapse_srv_lookup(struct fo_server *server) { @@ -697,6 +682,45 @@ fo_add_server(struct fo_service *service, const char *name, int port, return EOK; } +errno_t fo_add_server_list(struct fo_service *service, + struct fo_server *after_server, + struct fo_server_info *servers, + size_t num_servers, + struct srv_data *srv_data, + void *user_data, + bool primary, + struct fo_server **_last_server) +{ + struct fo_server *server = NULL; + struct fo_server *srv_list = NULL; + size_t i; + + for (i = 0; i < num_servers; i++) { + server = create_fo_server(service, servers[i].host, servers[i].port, + user_data, primary); + if (server == NULL) { + return ENOMEM; + } + + server->srv_data = srv_data; + DLIST_ADD_END(srv_list, server, struct fo_server *); + + DEBUG(SSSDBG_TRACE_FUNC, ("Inserted server '%s:%d' for service '%s'\n", + server->common->name, server->port, service->name)); + } + + if (srv_list != NULL) { + DLIST_ADD_LIST_AFTER(service->server_list, after_server, + srv_list, struct fo_server *); + } + + if (_last_server != NULL) { + *_last_server = server; + } + + return EOK; +} + static int get_first_server_entity(struct fo_service *service, struct fo_server **_server) { @@ -1057,17 +1081,6 @@ fo_resolve_service_recv(struct tevent_req *req, struct fo_server **server) *******************************************************************/ static void resolve_srv_done(struct tevent_req *subreq); -static void resolve_srv_cont(struct tevent_req *req); - -struct tevent_req *resolve_get_domain_send(TALLOC_CTX *mem_ctx, - struct tevent_context *ev, - struct fo_ctx *foctx, - struct resolv_ctx *resolv); - -static void resolve_getsrv_domain_done(struct tevent_req *req); -int resolve_get_domain_recv(struct tevent_req *req, - TALLOC_CTX *mem_ctx, - char **dns_domain); struct resolve_srv_state { struct fo_server *meta; @@ -1112,26 +1125,19 @@ resolve_srv_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev, * query collapsed * */ case SRV_NEUTRAL: /* Request SRV lookup */ - if (state->meta->srv_data->dns_domain == NULL) { - /* we need to look up our DNS domain first */ - DEBUG(SSSDBG_TRACE_FUNC, - ("SRV resolution of service '%s'. " - "dns_discovery_domain not specified. Need to look it up.\n", - server->service->name)); - subreq = resolve_get_domain_send(state, ev, ctx, resolv); - if (subreq == NULL) { - ret = ENOMEM; - goto done; - } - tevent_req_set_callback(subreq, resolve_getsrv_domain_done, req); - break; + if (ctx->srv_send_fn == NULL || ctx->srv_recv_fn == NULL) { + DEBUG(SSSDBG_OP_FAILURE, ("No SRV lookup plugin is set\n")); + ret = ENOTSUP; + goto done; } - /* we know the DNS domain, just do the lookup */ - DEBUG(SSSDBG_TRACE_FUNC, - ("SRV resolution of service '%s'. " - "Will use DNS discovery domain '%s'\n", - server->service->name, state->meta->srv_data->dns_domain)); - resolve_srv_cont(req); + + subreq = ctx->srv_send_fn(state, ev, + server->srv_data->srv, + server->srv_data->proto, + server->srv_data->discovery_domain, + ctx->srv_pvt); + + tevent_req_set_callback(subreq, resolve_srv_done, req); break; case SRV_RESOLVE_ERROR: /* query could not be resolved but don't retry yet */ ret = EIO; @@ -1157,149 +1163,92 @@ done: } static void -resolve_getsrv_domain_done(struct tevent_req *subreq) -{ - struct tevent_req *req = tevent_req_callback_data(subreq, - struct tevent_req); - struct resolve_srv_state *state = tevent_req_data(req, - struct resolve_srv_state); - int ret; - - ret = resolve_get_domain_recv(subreq, state->meta->srv_data, - &state->meta->srv_data->dns_domain); - talloc_zfree(subreq); - if (ret) { - tevent_req_error(req, ret); - return; - } - - resolve_srv_cont(req); -} - -static void -resolve_srv_cont(struct tevent_req *req) -{ - struct resolve_srv_state *state = tevent_req_data(req, - struct resolve_srv_state); - char *query; - struct tevent_req *subreq; - - query = get_srv_query(state, state->meta); - if (!query) { - tevent_req_error(req, ENOMEM); - return; - } - DEBUG(4, ("Searching for servers via SRV query '%s'\n", query)); - - subreq = resolv_getsrv_send(state, state->ev, state->resolv, query); - if (subreq == NULL) { - tevent_req_error(req, ENOMEM); - return; - } - tevent_req_set_callback(subreq, resolve_srv_done, req); -} - -static void resolve_srv_done(struct tevent_req *subreq) { struct tevent_req *req = tevent_req_callback_data(subreq, struct tevent_req); struct resolve_srv_state *state = tevent_req_data(req, struct resolve_srv_state); - struct ares_srv_reply *reply_list; - struct ares_srv_reply *reply; - struct fo_server *server = NULL; - struct fo_server *srv_list = NULL; + struct fo_server *last_server = NULL; + struct fo_server_info *primary_servers = NULL; + struct fo_server_info *backup_servers = NULL; + size_t num_primary_servers = 0; + size_t num_backup_servers = 0; + char *dns_domain = NULL; int ret; - int resolv_status; - ret = resolv_getsrv_recv(state, subreq, - &resolv_status, NULL, &reply_list); + ret = state->fo_ctx->srv_recv_fn(state, subreq, &dns_domain, + &primary_servers, &num_primary_servers, + &backup_servers, &num_backup_servers); talloc_free(subreq); - if (ret != EOK) { - DEBUG(1, ("SRV query failed: [%s]\n", - resolv_strerror(resolv_status))); - if (resolv_status == ARES_ENOTFOUND && - state->meta->srv_data->dns_domain != - state->meta->srv_data->discovery_domain && - state->meta->srv_data->dns_domain != - state->meta->srv_data->sssd_domain) { - /* The domain name could not be identified - * If the domain wasn't specified in the config - * file, also check whether the SSSD domain - * works. - * - * Programming note: It is safe to compare - * pointers here, because we're not copying - * the data, we're just reassigning the pointer - * for the active domain. - */ - talloc_free(state->meta->srv_data->dns_domain); - state->meta->srv_data->dns_domain = - state->meta->srv_data->sssd_domain; - resolve_srv_cont(req); - return; + switch (ret) { + case EOK: + if ((num_primary_servers == 0 || primary_servers == NULL) + && (num_backup_servers == 0 || backup_servers == NULL)) { + DEBUG(SSSDBG_CRIT_FAILURE, ("SRV lookup plugin returned EOK but " + "no servers\n")); + ret = EFAULT; + goto done; } - /* We need to make sure we reset this to NULL - * so that if we go online later, we re-check - * the DNS domain - */ - if (!state->meta->srv_data->discovery_domain) { - state->meta->srv_data->dns_domain = NULL; - } - - fo_set_port_status(state->meta, PORT_NOT_WORKING); - goto fail; - } + talloc_zfree(state->meta->srv_data->dns_domain); + state->meta->srv_data->dns_domain = talloc_steal(state->meta->srv_data, + dns_domain); - ret = resolv_sort_srv_reply(state, &reply_list); - if (ret != EOK) { - DEBUG(1, ("Could not sort the answers from DNS [%d]: %s\n", - ret, strerror(ret))); - fo_set_port_status(state->meta, PORT_NOT_WORKING); - goto fail; - } + last_server = state->meta; - for (reply = reply_list; reply; reply = reply->next) { - server = create_fo_server(state->service, reply->host, - reply->port, state->meta->user_data, - true); - if (!server) { - ret = ENOMEM; - goto fail; + if (primary_servers != NULL) { + ret = fo_add_server_list(state->service, last_server, + primary_servers, num_primary_servers, + state->meta->srv_data, + state->meta->user_data, + true, &last_server); + if (ret != EOK) { + goto done; + } } - server->srv_data = state->meta->srv_data; - DLIST_ADD_END(srv_list, server, struct fo_server *); - DEBUG(6, ("Inserted server '%s:%d' for service %s\n", - server->common->name, - server->port, - state->service->name)); - } + if (backup_servers != NULL) { + ret = fo_add_server_list(state->service, last_server, + primary_servers, num_primary_servers, + state->meta->srv_data, + state->meta->user_data, + false, NULL); + if (ret != EOK) { + goto done; + } + } - if (srv_list) { - DLIST_ADD_LIST_AFTER(state->service->server_list, state->meta, - srv_list, struct fo_server *); + state->out = state->meta->next; DLIST_REMOVE(state->service->server_list, state->meta); if (state->service->last_tried_server == state->meta) { - state->service->last_tried_server = srv_list; + state->service->last_tried_server = state->out; } - state->out = srv_list; set_srv_data_status(state->meta->srv_data, SRV_RESOLVED); - tevent_req_done(req); + + ret = EOK; + break; + case ERR_SRV_NOT_FOUND: + /* fall through */ + case ERR_SRV_LOOKUP_ERROR: + fo_set_port_status(state->meta, PORT_NOT_WORKING); + /* fall through */ + default: + DEBUG(SSSDBG_OP_FAILURE, ("Unable to resolve SRV [%d]: %s\n", + ret, sss_strerror(ret))); + } + +done: + if (ret != EOK) { + state->out = state->meta; + set_srv_data_status(state->meta->srv_data, SRV_RESOLVE_ERROR); + tevent_req_error(req, ret); return; - } else { - ret = EIO; - goto fail; } -fail: - state->out = state->meta; - set_srv_data_status(state->meta->srv_data, SRV_RESOLVE_ERROR); - tevent_req_error(req, ret); + tevent_req_done(req); } static int @@ -1327,101 +1276,6 @@ struct resolve_get_domain_state { char hostname[HOST_NAME_MAX]; }; -static void resolve_get_domain_done(struct tevent_req *subreq); - -struct tevent_req * -resolve_get_domain_send(TALLOC_CTX *mem_ctx, - struct tevent_context *ev, - struct fo_ctx *foctx, - struct resolv_ctx *resolv) -{ - int ret; - struct resolve_get_domain_state *state; - struct tevent_req *req, *subreq; - - req = tevent_req_create(mem_ctx, &state, struct resolve_get_domain_state); - if (!req) { - return NULL; - } - - ret = gethostname(state->hostname, HOST_NAME_MAX); - if (ret) { - ret = errno; - DEBUG(2, ("gethostname() failed: [%d]: %s\n",ret, strerror(ret))); - return NULL; - } - state->hostname[HOST_NAME_MAX-1] = '\0'; - DEBUG(7, ("Host name is: %s\n", state->hostname)); - - subreq = resolv_gethostbyname_send(state, ev, resolv, - state->hostname, - foctx->opts->family_order, - default_host_dbs); - if (!subreq) { - talloc_zfree(req); - return NULL; - } - tevent_req_set_callback(subreq, resolve_get_domain_done, req); - - return req; -} - -static void resolve_get_domain_done(struct tevent_req *subreq) -{ - struct tevent_req *req = tevent_req_callback_data(subreq, - struct tevent_req); - struct resolve_get_domain_state *state = tevent_req_data(req, - struct resolve_get_domain_state); - struct resolv_hostent *rhostent; - int ret; - int resolv_status; - - ret = resolv_gethostbyname_recv(subreq, req, &resolv_status, - NULL, &rhostent); - talloc_zfree(subreq); - if (ret) { - DEBUG(SSSDBG_OP_FAILURE, - ("Could not get fully qualified name for host name %s " - "error [%d]: %s, resolver returned: [%d]: %s\n", - state->hostname, ret, strerror(ret), resolv_status, - resolv_strerror(resolv_status))); - /* We'll proceed with hostname in this case */ - } else { - DEBUG(SSSDBG_TRACE_LIBS, ("The full FQDN is: %s\n", rhostent->name)); - state->fqdn = rhostent->name; - } - tevent_req_done(req); -} - -int resolve_get_domain_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, - char **dns_domain) -{ - struct resolve_get_domain_state *state = tevent_req_data(req, - struct resolve_get_domain_state); - char *fqdn; - char *domptr; - - TEVENT_REQ_RETURN_ON_ERROR(req); - - fqdn = state->fqdn ? state->fqdn : state->hostname; - domptr = strchr(fqdn, '.'); - - if (!domptr || (*(domptr+1) == '\0')) { - /* If the FQDN did not contain a dot or the dot was the last character - * (broken DNS server perhaps */ - *dns_domain = talloc_strdup(mem_ctx, fqdn); - } else { - domptr++; - *dns_domain = talloc_strdup(mem_ctx, domptr); - } - - if (*dns_domain == NULL) { - return ENOMEM; - } - - return EOK; -} - static void set_server_common_status(struct server_common *common, enum server_status status) -- 1.7.11.7