| #include <net-snmp/net-snmp-config.h> |
| #include <net-snmp/net-snmp-features.h> |
| |
| #include <net-snmp/net-snmp-includes.h> |
| #include <net-snmp/agent/net-snmp-agent-includes.h> |
| |
| #include <net-snmp/agent/row_merge.h> |
| |
| #if HAVE_STRING_H |
| #include <string.h> |
| #else |
| #include <strings.h> |
| #endif |
| |
| netsnmp_feature_provide(row_merge) |
| netsnmp_feature_child_of(row_merge, row_merge_all) |
| netsnmp_feature_child_of(row_merge_all, mib_helpers) |
| |
| |
| #ifndef NETSNMP_FEATURE_REMOVE_ROW_MERGE |
| /** @defgroup row_merge row_merge |
| * Calls sub handlers with request for one row at a time. |
| * @ingroup utilities |
| * This helper splits a whole bunch of requests into chunks based on the row |
| * index that they refer to, and passes all requests for a given row to the lower handlers. |
| * This is useful for handlers that don't want to process multiple rows at the |
| * same time, but are happy to iterate through the request list for a single row. |
| * @{ |
| */ |
| |
| /** returns a row_merge handler that can be injected into a given |
| * handler chain. |
| */ |
| netsnmp_mib_handler * |
| netsnmp_get_row_merge_handler(int prefix_len) |
| { |
| netsnmp_mib_handler *ret = NULL; |
| ret = netsnmp_create_handler("row_merge", |
| netsnmp_row_merge_helper_handler); |
| if (ret) { |
| ret->myvoid = (void *)(intptr_t)prefix_len; |
| } |
| return ret; |
| } |
| |
| /** functionally the same as calling netsnmp_register_handler() but also |
| * injects a row_merge handler at the same time for you. */ |
| netsnmp_feature_child_of(register_row_merge, row_merge_all) |
| #ifndef NETSNMP_FEATURE_REMOVE_REGISTER_ROW_MERGE |
| int |
| netsnmp_register_row_merge(netsnmp_handler_registration *reginfo) |
| { |
| netsnmp_inject_handler(reginfo, |
| netsnmp_get_row_merge_handler(reginfo->rootoid_len+1)); |
| return netsnmp_register_handler(reginfo); |
| } |
| #endif /* NETSNMP_FEATURE_REMOVE_REGISTER_ROW_MERGE */ |
| |
| static void |
| _rm_status_free(void *mem) |
| { |
| netsnmp_row_merge_status *rm_status = (netsnmp_row_merge_status*)mem; |
| |
| if (NULL != rm_status->saved_requests) |
| free(rm_status->saved_requests); |
| |
| if (NULL != rm_status->saved_status) |
| free(rm_status->saved_status); |
| |
| free(mem); |
| } |
| |
| |
| /** retrieve row_merge_status |
| */ |
| netsnmp_row_merge_status * |
| netsnmp_row_merge_status_get(netsnmp_handler_registration *reginfo, |
| netsnmp_agent_request_info *reqinfo, |
| int create_missing) |
| { |
| netsnmp_row_merge_status *rm_status; |
| char buf[64]; |
| int rc; |
| |
| /* |
| * see if we've already been here |
| */ |
| rc = snprintf(buf, sizeof(buf), "row_merge:%p", reginfo); |
| if ((-1 == rc) || ((size_t)rc >= sizeof(buf))) { |
| snmp_log(LOG_ERR,"error creating key\n"); |
| return NULL; |
| } |
| |
| rm_status = (netsnmp_row_merge_status*)netsnmp_agent_get_list_data(reqinfo, buf); |
| if ((NULL == rm_status) && create_missing) { |
| netsnmp_data_list *data_list; |
| |
| rm_status = SNMP_MALLOC_TYPEDEF(netsnmp_row_merge_status); |
| if (NULL == rm_status) { |
| snmp_log(LOG_ERR,"error allocating memory\n"); |
| return NULL; |
| } |
| data_list = netsnmp_create_data_list(buf, rm_status, |
| _rm_status_free); |
| if (NULL == data_list) { |
| free(rm_status); |
| return NULL; |
| } |
| netsnmp_agent_add_list_data(reqinfo, data_list); |
| } |
| |
| return rm_status; |
| } |
| |
| /** Determine if this is the first row |
| * |
| * returns 1 if this is the first row for this pass of the handler. |
| */ |
| int |
| netsnmp_row_merge_status_first(netsnmp_handler_registration *reginfo, |
| netsnmp_agent_request_info *reqinfo) |
| { |
| netsnmp_row_merge_status *rm_status; |
| |
| /* |
| * find status |
| */ |
| rm_status = netsnmp_row_merge_status_get(reginfo, reqinfo, 0); |
| if (NULL == rm_status) |
| return 0; |
| |
| return (rm_status->count == 1) ? 1 : (rm_status->current == 1); |
| } |
| |
| /** Determine if this is the last row |
| * |
| * returns 1 if this is the last row for this pass of the handler. |
| */ |
| int |
| netsnmp_row_merge_status_last(netsnmp_handler_registration *reginfo, |
| netsnmp_agent_request_info *reqinfo) |
| { |
| netsnmp_row_merge_status *rm_status; |
| |
| /* |
| * find status |
| */ |
| rm_status = netsnmp_row_merge_status_get(reginfo, reqinfo, 0); |
| if (NULL == rm_status) |
| return 0; |
| |
| return (rm_status->count == 1) ? 1 : |
| (rm_status->current == rm_status->rows); |
| } |
| |
| |
| #define ROW_MERGE_WAITING 0 |
| #define ROW_MERGE_ACTIVE 1 |
| #define ROW_MERGE_DONE 2 |
| #define ROW_MERGE_HEAD 3 |
| |
| /** Implements the row_merge handler */ |
| int |
| netsnmp_row_merge_helper_handler(netsnmp_mib_handler *handler, |
| netsnmp_handler_registration *reginfo, |
| netsnmp_agent_request_info *reqinfo, |
| netsnmp_request_info *requests) |
| { |
| netsnmp_request_info *request, **saved_requests; |
| char *saved_status; |
| netsnmp_row_merge_status *rm_status; |
| int i, j, ret, tail, count, final_rc = SNMP_ERR_NOERROR; |
| |
| /* |
| * Use the prefix length as supplied during registration, rather |
| * than trying to second-guess what the MIB implementer wanted. |
| */ |
| int SKIP_OID = (int)(intptr_t)handler->myvoid; |
| |
| DEBUGMSGTL(("helper:row_merge", "Got request (%d): ", SKIP_OID)); |
| DEBUGMSGOID(("helper:row_merge", reginfo->rootoid, reginfo->rootoid_len)); |
| DEBUGMSG(("helper:row_merge", "\n")); |
| |
| /* |
| * find or create status |
| */ |
| rm_status = netsnmp_row_merge_status_get(reginfo, reqinfo, 1); |
| |
| /* |
| * Count the requests, and set up an array to keep |
| * track of the original order. |
| */ |
| for (count = 0, request = requests; request; request = request->next) { |
| DEBUGIF("helper:row_merge") { |
| DEBUGMSGTL(("helper:row_merge", " got varbind: ")); |
| DEBUGMSGOID(("helper:row_merge", request->requestvb->name, |
| request->requestvb->name_length)); |
| DEBUGMSG(("helper:row_merge", "\n")); |
| } |
| count++; |
| } |
| |
| /* |
| * Optimization: skip all this if there is just one request |
| */ |
| if(count == 1) { |
| rm_status->count = count; |
| if (requests->processed) |
| return SNMP_ERR_NOERROR; |
| return netsnmp_call_next_handler(handler, reginfo, reqinfo, requests); |
| } |
| |
| /* |
| * we really should only have to do this once, instead of every pass. |
| * as a precaution, we'll do it every time, but put in some asserts |
| * to see if we have to. |
| */ |
| /* |
| * if the count changed, re-do everything |
| */ |
| if ((0 != rm_status->count) && (rm_status->count != count)) { |
| /* |
| * ok, i know next/bulk can cause this condition. Probably |
| * GET, too. need to rethink this mode counting. maybe |
| * add the mode to the rm_status structure? xxx-rks |
| */ |
| if ((reqinfo->mode != MODE_GET) && |
| (reqinfo->mode != MODE_GETNEXT) && |
| (reqinfo->mode != MODE_GETBULK)) { |
| netsnmp_assert((NULL != rm_status->saved_requests) && |
| (NULL != rm_status->saved_status)); |
| } |
| DEBUGMSGTL(("helper:row_merge", "count changed! do over...\n")); |
| |
| SNMP_FREE(rm_status->saved_requests); |
| SNMP_FREE(rm_status->saved_status); |
| |
| rm_status->count = 0; |
| rm_status->rows = 0; |
| } |
| |
| if (0 == rm_status->count) { |
| /* |
| * allocate memory for saved structure |
| */ |
| rm_status->saved_requests = |
| (netsnmp_request_info**)calloc(count+1, |
| sizeof(netsnmp_request_info*)); |
| rm_status->saved_status = (char*)calloc(count,sizeof(char)); |
| } |
| |
| saved_status = rm_status->saved_status; |
| saved_requests = rm_status->saved_requests; |
| |
| /* |
| * set up saved requests, and set any processed requests to done |
| */ |
| i = 0; |
| for (request = requests; request; request = request->next, i++) { |
| if (request->processed) { |
| saved_status[i] = ROW_MERGE_DONE; |
| DEBUGMSGTL(("helper:row_merge", " skipping processed oid: ")); |
| DEBUGMSGOID(("helper:row_merge", request->requestvb->name, |
| request->requestvb->name_length)); |
| DEBUGMSG(("helper:row_merge", "\n")); |
| } |
| else |
| saved_status[i] = ROW_MERGE_WAITING; |
| if (0 != rm_status->count) |
| netsnmp_assert(saved_requests[i] == request); |
| saved_requests[i] = request; |
| saved_requests[i]->prev = NULL; |
| } |
| saved_requests[i] = NULL; |
| |
| /* |
| * Note that saved_requests[count] is valid |
| * (because of the 'count+1' in the calloc above), |
| * but NULL (since it's past the end of the list). |
| * This simplifies the re-linking later. |
| */ |
| |
| /* |
| * Work through the (unprocessed) requests in order. |
| * For each of these, search the rest of the list for any |
| * matching indexes, and link them into a new list. |
| */ |
| for (i=0; i<count; i++) { |
| if (saved_status[i] != ROW_MERGE_WAITING) |
| continue; |
| |
| if (0 == rm_status->count) |
| rm_status->rows++; |
| DEBUGMSGTL(("helper:row_merge", " row %d oid[%d]: ", rm_status->rows, i)); |
| DEBUGMSGOID(("helper:row_merge", saved_requests[i]->requestvb->name, |
| saved_requests[i]->requestvb->name_length)); |
| DEBUGMSG(("helper:row_merge", "\n")); |
| |
| saved_requests[i]->next = NULL; |
| saved_status[i] = ROW_MERGE_HEAD; |
| tail = i; |
| for (j=i+1; j<count; j++) { |
| if (saved_status[j] != ROW_MERGE_WAITING) |
| continue; |
| |
| DEBUGMSGTL(("helper:row_merge", "? oid[%d]: ", j)); |
| DEBUGMSGOID(("helper:row_merge", |
| saved_requests[j]->requestvb->name, |
| saved_requests[j]->requestvb->name_length)); |
| if (!snmp_oid_compare( |
| saved_requests[i]->requestvb->name+SKIP_OID, |
| saved_requests[i]->requestvb->name_length-SKIP_OID, |
| saved_requests[j]->requestvb->name+SKIP_OID, |
| saved_requests[j]->requestvb->name_length-SKIP_OID)) { |
| DEBUGMSG(("helper:row_merge", " match\n")); |
| saved_requests[tail]->next = saved_requests[j]; |
| saved_requests[j]->next = NULL; |
| saved_requests[j]->prev = saved_requests[tail]; |
| saved_status[j] = ROW_MERGE_ACTIVE; |
| tail = j; |
| } |
| else |
| DEBUGMSG(("helper:row_merge", " no match\n")); |
| } |
| } |
| |
| /* |
| * not that we have a list for each row, call next handler... |
| */ |
| if (0 == rm_status->count) |
| rm_status->count = count; |
| rm_status->current = 0; |
| for (i=0; i<count; i++) { |
| if (saved_status[i] != ROW_MERGE_HEAD) |
| continue; |
| |
| /* |
| * found the head of a new row, |
| * call the next handler with this list |
| */ |
| rm_status->current++; |
| ret = netsnmp_call_next_handler(handler, reginfo, reqinfo, |
| saved_requests[i]); |
| if (ret != SNMP_ERR_NOERROR) { |
| snmp_log(LOG_WARNING, |
| "bad rc (%d) from next handler in row_merge\n", ret); |
| if (SNMP_ERR_NOERROR == final_rc) |
| final_rc = ret; |
| } |
| } |
| |
| /* |
| * restore original linked list |
| */ |
| for (i=0; i<count; i++) { |
| saved_requests[i]->next = saved_requests[i+1]; |
| if (i>0) |
| saved_requests[i]->prev = saved_requests[i-1]; |
| } |
| |
| return final_rc; |
| } |
| |
| /** |
| * initializes the row_merge helper which then registers a row_merge |
| * handler as a run-time injectable handler for configuration file |
| * use. |
| */ |
| void |
| netsnmp_init_row_merge(void) |
| { |
| netsnmp_register_handler_by_name("row_merge", |
| netsnmp_get_row_merge_handler(-1)); |
| } |
| #else /* NETSNMP_FEATURE_REMOVE_ROW_MERGE */ |
| netsnmp_feature_unused(row_merge); |
| #endif /* NETSNMP_FEATURE_REMOVE_ROW_MERGE */ |
| |
| |
| /** @} */ |
| |
