diff options
Diffstat (limited to 'lib/northbound_notif.c')
| -rw-r--r-- | lib/northbound_notif.c | 680 |
1 files changed, 680 insertions, 0 deletions
diff --git a/lib/northbound_notif.c b/lib/northbound_notif.c new file mode 100644 index 000000000..b75c86561 --- /dev/null +++ b/lib/northbound_notif.c @@ -0,0 +1,680 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * December 1 2024, Christian Hopps <chopps@labn.net> + * + * Copyright (c) 2024, LabN Consulting, L.L.C. + * + */ +#include <zebra.h> +#include "debug.h" +#include "lib_errors.h" +#include "typesafe.h" +#include "northbound.h" +#include "mgmt_be_client.h" + +#define __dbg(fmt, ...) DEBUGD(&nb_dbg_notif, "NB_OP_CHANGE: %s: " fmt, __func__, ##__VA_ARGS__) +#define __log_err(fmt, ...) zlog_err("NB_OP_CHANGE: %s: ERROR: " fmt, __func__, ##__VA_ARGS__) + +#define NB_NOTIF_TIMER_MSEC (10) /* 10msec */ + +/* + * ADDS: + * - Less specific: + * - Any new add will cause more specific pending adds to be dropped and equal + * or more specific deletes to be dropped. + * - More specific: + * - Ignore any new add that is the same or more specific than an existing add. + * - A new add that is more specific than a delete should change the delete + * into an add query (since adds are reported as a replace). + * + * DELETES: + * - Less specific: + * - Any new delete will cause more specific pending deletes to be dropped and + * equal or more specific adds to be dropped. + * - More specific: + * - Ignore new deletes that are the same or more specific than existing + * deletes. + * - A new delete that is more specific than an add can be dropped since we + * use replacement methodology for the add. + * + * One thing we have to pay close attention to is that the state is going to be + * queried when the notification sent, not when we are told of the change. + */ + +DEFINE_MTYPE_STATIC(LIB, OP_CHANGE, "NB Oper Change"); +DEFINE_MTYPE_STATIC(LIB, OP_CHANGES_GROUP, "NB Oper Changes Group"); +DEFINE_MTYPE_STATIC(LIB, NB_NOTIF_WALK_ARGS, "NB Notify Oper Walk"); + +struct op_change { + RB_ENTRY(op_change) link; + char path[]; +}; + +/* + * RB tree for op_change + */ +static int op_change_cmp(const struct op_change *e1, const struct op_change *e2); +RB_HEAD(op_changes, op_change); +RB_PROTOTYPE(op_changes, op_change, link, op_change_cmp) +RB_GENERATE(op_changes, op_change, link, op_change_cmp) + +struct op_changes nb_notif_adds = RB_INITIALIZER(&nb_notif_adds); +struct op_changes nb_notif_dels = RB_INITIALIZER(&nb_notif_dels); +struct event_loop *nb_notif_master; +struct event *nb_notif_timer; +void *nb_notif_walk; + +const char **nb_notif_filters; + +/* + * We maintain a queue of change lists one entry per query and notification send + * action + */ +PREDECL_LIST(op_changes_queue); +struct op_changes_group { + struct op_changes_queue_item item; + struct op_changes adds; + struct op_changes dels; + struct op_changes *cur_changes; /* used when walking */ + struct op_change *cur_change; /* " " " */ +}; + +DECLARE_LIST(op_changes_queue, struct op_changes_group, item); +static struct op_changes_queue_head op_changes_queue; + +struct nb_notif_walk_args { + struct op_changes_group *group; + struct lyd_node *tree; +}; + +static void nb_notif_set_walk_timer(void); + + +static int pathncmp(const char *s1, const char *s2, size_t n) +{ + size_t i = 0; + + while (i < n && *s1 && *s2) { + char c1 = *s1; + char c2 = *s2; + + if ((c1 == '\'' && c2 == '\"') || (c1 == '\"' && c2 == '\'')) { + s1++; + s2++; + i++; + continue; + } + if (c1 != c2) + return (unsigned char)c1 - (unsigned char)c2; + s1++; + s2++; + i++; + } + if (i < n) + return (unsigned char)*s1 - (unsigned char)*s2; + return 0; +} + +static int pathcmp(const char *s1, const char *s2) +{ + while (*s1 && *s2) { + char c1 = *s1; + char c2 = *s2; + + if ((c1 == '\'' && c2 == '\"') || (c1 == '\"' && c2 == '\'')) { + s1++; + s2++; + continue; + } + if (c1 != c2) + return (unsigned char)c1 - (unsigned char)c2; + s1++; + s2++; + } + return (unsigned char)*s1 - (unsigned char)*s2; +} + + +static int op_change_cmp(const struct op_change *e1, const struct op_change *e2) +{ + return pathcmp(e1->path, e2->path); +} + +static struct op_change *op_change_alloc(const char *path) +{ + struct op_change *note; + size_t ssize = strlen(path) + 1; + + note = XMALLOC(MTYPE_OP_CHANGE, sizeof(*note) + ssize); + memset(note, 0, sizeof(*note)); + strlcpy(note->path, path, ssize); + + return note; +} + +static void op_change_free(struct op_change *note) +{ + XFREE(MTYPE_OP_CHANGE, note); +} + +/** + * op_changes_group_push() - Save the current set of changes on the queue. + * + * This function will save the current set of changes on the queue and + * initialize a new set of changes. + */ +static void op_changes_group_push(void) +{ + struct op_changes_group *changes; + + if (RB_EMPTY(op_changes, &nb_notif_adds) && RB_EMPTY(op_changes, &nb_notif_dels)) + return; + + __dbg("pushing current oper changes onto queue"); + + changes = XCALLOC(MTYPE_OP_CHANGES_GROUP, sizeof(*changes)); + changes->adds = nb_notif_adds; + changes->dels = nb_notif_dels; + op_changes_queue_add_tail(&op_changes_queue, changes); + + RB_INIT(op_changes, &nb_notif_adds); + RB_INIT(op_changes, &nb_notif_dels); +} + +static void op_changes_group_free(struct op_changes_group *group) +{ + struct op_change *e, *next; + + RB_FOREACH_SAFE (e, op_changes, &group->adds, next) { + RB_REMOVE(op_changes, &group->adds, e); + op_change_free(e); + } + RB_FOREACH_SAFE (e, op_changes, &group->dels, next) { + RB_REMOVE(op_changes, &group->dels, e); + op_change_free(e); + } + XFREE(MTYPE_OP_CHANGES_GROUP, group); +} + +static struct op_change *__find_less_specific(struct op_changes *head, struct op_change *note) +{ + struct op_change *e; + size_t plen; + + /* + * RB_NFIND finds equal or greater (more specific) than the key, + * so the previous node will be a less specific or no match that + * sorts earlier. We want to find when we are a more specific + * match. + */ + e = RB_NFIND(op_changes, head, note); + if (e) + e = RB_PREV(op_changes, e); + else + e = RB_MAX(op_changes, head); + if (!e) + return NULL; + plen = strlen(e->path); + if (pathncmp(e->path, note->path, plen)) + return NULL; + /* equal would have been returned from RB_NFIND() then we went RB_PREV */ + assert(strlen(note->path) != plen); + return e; +} + +static void __drop_eq_or_more_specific(struct op_changes *head, const char *path, int plen, + struct op_change *next) +{ + struct op_change *e; + + for (e = next; e != NULL; e = next) { + /* if the prefix no longer matches we are done */ + if (pathncmp(path, e->path, plen)) + break; + __dbg("dropping more specific %s: %s", head == &nb_notif_adds ? "add" : "delete", + e->path); + next = RB_NEXT(op_changes, e); + RB_REMOVE(op_changes, head, e); + op_change_free(e); + } +} + +static void __op_change_add_del(const char *path, struct op_changes *this_head, + struct op_changes *other_head) +{ + /* find out if this has been subsumed or will subsume */ + + const char *op = this_head == &nb_notif_adds ? "add" : "delete"; + struct op_change *note = op_change_alloc(path); + struct op_change *next, *e; + int plen; + + __dbg("processing oper %s change path: %s", op, path); + + /* + * See if we are already covered by a more general `op`. + */ + e = __find_less_specific(this_head, note); + if (e) { + __dbg("%s path already covered by: %s", op, e->path); + op_change_free(note); + return; + } + + /* + * Handle having a less-specific `other op`. + */ + e = __find_less_specific(other_head, note); + if (e) { + if (this_head == &nb_notif_dels) { + /* + * If we have a less-specific add then drop this + * more-specific delete as the add-replace will remove + * this missing state. + */ + __dbg("delete path already covered add-replace: %s", e->path); + } else { + /* + * If we have a less-specific delete, convert the delete + * to an add, and drop this more-specific add. The new + * less-specific add will pick up the more specific add + * during the walk and as adds are processed as replaces + * any other existing state that was to be deleted will + * still be deleted (unless it also returns) by the replace. + */ + __dbg("add covered, converting covering delete to add-replace: %s", e->path); + RB_REMOVE(op_changes, other_head, e); + __op_change_add_del(e->path, &nb_notif_adds, &nb_notif_dels); + op_change_free(e); + } + op_change_free(note); + return; + } + + e = RB_INSERT(op_changes, this_head, note); + if (e) { + __dbg("path already in %s tree: %s", op, path); + op_change_free(note); + return; + } + + __dbg("scanning for subsumed or subsuming: %s", path); + + plen = strlen(path); + + next = RB_NEXT(op_changes, note); + __drop_eq_or_more_specific(this_head, path, plen, next); + + /* Drop exact match or more specific `other op` */ + next = RB_NFIND(op_changes, other_head, note); + __drop_eq_or_more_specific(other_head, path, plen, next); + + nb_notif_set_walk_timer(); +} + +static void nb_notif_add(const char *path) +{ + __op_change_add_del(path, &nb_notif_adds, &nb_notif_dels); +} + + +static void nb_notif_delete(const char *path) +{ + __op_change_add_del(path, &nb_notif_dels, &nb_notif_adds); +} + +struct lyd_node *nb_op_update(struct lyd_node *tree, const char *path, const char *value) +{ + struct lyd_node *dnode; + const char *abs_path = NULL; + + __dbg("updating path: %s with value: %s", path, value); + + dnode = yang_state_new(tree, path, value); + + if (path[0] == '/') + abs_path = path; + else + abs_path = lyd_path(dnode, LYD_PATH_STD, NULL, 0); + + nb_notif_add(abs_path); + + if (abs_path != path) + free((char *)abs_path); + + return dnode; +} + +void nb_op_update_delete(struct lyd_node *tree, const char *path) +{ + char *abs_path = NULL; + + __dbg("deleting path: %s", path); + + if (path && path[0] == '/') + abs_path = (char *)path; + else { + assert(tree); + abs_path = lyd_path(tree, LYD_PATH_STD, NULL, 0); + assert(abs_path); + if (path) { + char *tmp = darr_strdup(abs_path); + + free(abs_path); + abs_path = tmp; + if (*darr_last(abs_path) != '/') + darr_in_strcat(abs_path, "/"); + assert(abs_path); /* silence bad CLANG NULL warning */ + darr_in_strcat(abs_path, path); + } + } + + yang_state_delete(tree, path); + + nb_notif_delete(abs_path); + + if (abs_path != path) { + if (path) + darr_free(abs_path); + else + free(abs_path); + } +} + +PRINTFRR(2, 0) +struct lyd_node *nb_op_update_vpathf(struct lyd_node *tree, const char *path_fmt, const char *value, + va_list ap) +{ + struct lyd_node *dnode; + char *path; + + path = darr_vsprintf(path_fmt, ap); + dnode = nb_op_update(tree, path, value); + darr_free(path); + + return dnode; +} + +struct lyd_node *nb_op_update_pathf(struct lyd_node *tree, const char *path_fmt, const char *value, + ...) +{ + struct lyd_node *dnode; + va_list ap; + + va_start(ap, value); + dnode = nb_op_update_vpathf(tree, path_fmt, value, ap); + va_end(ap); + + return dnode; +} + +PRINTFRR(2, 0) +void nb_op_update_delete_vpathf(struct lyd_node *tree, const char *path_fmt, va_list ap) +{ + char *path; + + path = darr_vsprintf(path_fmt, ap); + nb_op_update_delete(tree, path); + darr_free(path); +} + +void nb_op_update_delete_pathf(struct lyd_node *tree, const char *path_fmt, ...) +{ + va_list ap; + + va_start(ap, path_fmt); + nb_op_update_delete_vpathf(tree, path_fmt, ap); + va_end(ap); +} + + +PRINTFRR(3, 0) +struct lyd_node *nb_op_vupdatef(struct lyd_node *tree, const char *path, const char *val_fmt, + va_list ap) +{ + struct lyd_node *dnode; + char *value; + + value = darr_vsprintf(val_fmt, ap); + dnode = nb_op_update(tree, path, value); + darr_free(value); + + return dnode; +} + + +struct lyd_node *nb_op_updatef(struct lyd_node *tree, const char *path, const char *val_fmt, ...) +{ + struct lyd_node *dnode; + va_list ap; + + va_start(ap, val_fmt); + dnode = nb_op_vupdatef(tree, path, val_fmt, ap); + va_end(ap); + + return dnode; +} + +static struct op_changes_group *op_changes_group_next(void) +{ + struct op_changes_group *group; + + group = op_changes_queue_pop(&op_changes_queue); + if (!group) { + op_changes_group_push(); + group = op_changes_queue_pop(&op_changes_queue); + } + if (!group) + return NULL; + group->cur_changes = &group->dels; + group->cur_change = RB_MIN(op_changes, group->cur_changes); + if (!group->cur_change) { + group->cur_changes = &group->adds; + group->cur_change = RB_MIN(op_changes, group->cur_changes); + assert(group->cur_change); + } + return group; +} + +/* ---------------------------- */ +/* Query for changes and notify */ +/* ---------------------------- */ + +static void timer_walk_continue(struct event *event); + +static enum nb_error oper_walk_done(const struct lyd_node *tree, void *arg, enum nb_error ret) +{ + struct nb_notif_walk_args *args = arg; + struct op_changes_group *group = args->group; + const char *path = group->cur_change->path; + const char *op = group->cur_changes == &group->adds ? "add" : "delete"; + + /* we don't send batches when yielding as we need completed edit in any patch */ + assert(ret != NB_YIELD); + + nb_notif_walk = NULL; + + if (ret == NB_ERR_NOT_FOUND) { + __dbg("Path not found while walking oper tree: %s", path); + XFREE(MTYPE_NB_NOTIF_WALK_ARGS, args); + return ret; + } + /* Something else went wrong with the walk */ + if (ret != NB_OK) { +error: + __log_err("Error notifying for datastore change on path: %s: %s", path, + nb_err_name(ret)); + XFREE(MTYPE_NB_NOTIF_WALK_ARGS, args); + /* XXX Need to inform mgmtd/front-ends things are out-of-sync */ + return ret; + } + + __dbg("done with oper-path collection for %s path: %s", op, path); + + /* Do we need this? */ + while (tree->parent) + tree = lyd_parent(tree); + + /* Send the add (replace) notification */ + if (mgmt_be_send_ds_replace_notification(path, tree)) { + ret = NB_ERR; + goto error; + } + + /* + * Advance to next change (either dels or adds or both). + */ + + group->cur_change = RB_NEXT(op_changes, group->cur_change); + if (!group->cur_change) { + __dbg("done with oper-path collection for group"); + op_changes_group_free(group); + + group = op_changes_group_next(); + args->group = group; + if (!group) { + __dbg("done with ALL oper-path collection for notification"); + XFREE(MTYPE_NB_NOTIF_WALK_ARGS, args); + goto done; + } + } + + event_add_timer_msec(nb_notif_master, timer_walk_continue, args, 0, &nb_notif_timer); +done: + /* Done with current walk and scheduled next one if there is more */ + nb_notif_walk = NULL; + + return NB_OK; +} + +static LY_ERR nb_notify_delete_changes(struct nb_notif_walk_args *args) +{ + struct op_changes_group *group = args->group; + LY_ERR err; + + group->cur_change = RB_MIN(op_changes, group->cur_changes); + while (group->cur_change) { + err = mgmt_be_send_ds_delete_notification(group->cur_change->path); + assert(err == LY_SUCCESS); /* XXX */ + + group->cur_change = RB_NEXT(op_changes, group->cur_change); + } + + return LY_SUCCESS; +} + +static void timer_walk_continue(struct event *event) +{ + struct nb_notif_walk_args *args = EVENT_ARG(event); + struct op_changes_group *group = args->group; + const char *path; + LY_ERR err; + + /* + * Notify about deletes until we have add changes to collect. + */ + while (group->cur_changes == &group->dels) { + err = nb_notify_delete_changes(args); + assert(err == LY_SUCCESS); /* XXX */ + assert(!group->cur_change); /* we send all the deletes in one message */ + + /* after deletes advance to adds */ + group->cur_changes = &group->adds; + group->cur_change = RB_MIN(op_changes, group->cur_changes); + if (group->cur_change) + break; + + __dbg("done with oper-path change group"); + op_changes_group_free(group); + + group = op_changes_group_next(); + args->group = group; + if (!group) { + __dbg("done with ALL oper-path changes"); + XFREE(MTYPE_NB_NOTIF_WALK_ARGS, args); + return; + } + } + + path = group->cur_change->path; + __dbg("starting next oper-path replace walk for path: %s", path); + nb_notif_walk = nb_oper_walk(path, NULL, 0, false, NULL, NULL, oper_walk_done, args); +} + +static void timer_walk_start(struct event *event) +{ + struct op_changes_group *group; + struct nb_notif_walk_args *args; + + __dbg("oper-state change notification timer fires"); + + group = op_changes_group_next(); + if (!group) { + __dbg("no oper changes to notify"); + return; + } + + args = XCALLOC(MTYPE_NB_NOTIF_WALK_ARGS, sizeof(*args)); + args->group = group; + + EVENT_ARG(event) = args; + timer_walk_continue(event); +} + +static void nb_notif_set_walk_timer(void) +{ + if (nb_notif_walk) { + __dbg("oper-state walk already in progress."); + return; + } + if (event_is_scheduled(nb_notif_timer)) { + __dbg("oper-state notification timer already set."); + return; + } + + __dbg("oper-state notification setting timer to fire in: %d msec ", NB_NOTIF_TIMER_MSEC); + event_add_timer_msec(nb_notif_master, timer_walk_start, NULL, NB_NOTIF_TIMER_MSEC, + &nb_notif_timer); +} + +void nb_notif_set_filters(const char **selectors, bool replace) +{ + const char **csp; + + if (replace) { + darr_free_free(nb_notif_filters); + nb_notif_filters = selectors; + return; + } + darr_foreach_p (selectors, csp) + *darr_append(nb_notif_filters) = *csp; + darr_free(selectors); +} + +void nb_notif_init(struct event_loop *tm) +{ + nb_notif_master = tm; + op_changes_queue_init(&op_changes_queue); +} + +void nb_notif_terminate(void) +{ + struct nb_notif_walk_args *args; + struct op_changes_group *group; + + EVENT_OFF(nb_notif_timer); + + if (nb_notif_walk) { + nb_oper_cancel_walk(nb_notif_walk); + /* need to free the group that's in the walk */ + args = nb_oper_walk_finish_arg(nb_notif_walk); + if (args) + op_changes_group_free(args->group); + nb_notif_walk = NULL; + } + + while ((group = op_changes_group_next())) + op_changes_group_free(group); + + darr_free_free(nb_notif_filters); +} |