diff --git a/src/ticket.c b/src/ticket.c index 34209fa..09743f7 100644 --- a/src/ticket.c +++ b/src/ticket.c @@ -1,1287 +1,1289 @@ /* * Copyright (C) 2011 Jiaju Zhang * Copyright (C) 2013-2014 Philipp Marek * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include #include #include #include #include #include #include #include #include #include "b_config.h" #include "ticket.h" #include "config.h" #include "pacemaker.h" #include "inline-fn.h" #include "log.h" #include "booth.h" #include "raft.h" #include "handler.h" #include "request.h" #define TK_LINE 256 extern int TIME_RES; /* Untrusted input, must fit (incl. \0) in a buffer of max chars. */ int check_max_len_valid(const char *s, int max) { int i; for(i=0; iticket_count; i++) { if (!strncmp(booth_conf->ticket[i].name, ticket, sizeof(booth_conf->ticket[i].name))) { if (found) *found = booth_conf->ticket + i; return 1; } } return 0; } int check_ticket(char *ticket, struct ticket_config **found) { if (found) *found = NULL; if (!booth_conf) return 0; if (!check_max_len_valid(ticket, sizeof(booth_conf->ticket[0].name))) return 0; return find_ticket_by_name(ticket, found); } int check_site(char *site, int *is_local) { struct booth_site *node; if (!check_max_len_valid(site, sizeof(node->addr_string))) return 0; if (find_site_by_name(site, &node, 0)) { *is_local = node->local; return 1; } return 0; } /* is it safe to commit the grant? * if we didn't hear from all sites on the initial grant, we may * need to delay the commit * * TODO: investigate possibility to devise from history whether a * missing site could be holding a ticket or not */ static int ticket_dangerous(struct ticket_config *tk) { int tdiff; /* we may be invoked often, don't spam the log unnecessarily */ static int no_log_delay_msg; if (!is_time_set(&tk->delay_commit)) return 0; if (is_past(&tk->delay_commit) || all_sites_replied(tk)) { if (tk->leader == local) { tk_log_info("%s, committing to CIB", is_past(&tk->delay_commit) ? "ticket delay expired" : "all sites replied"); } time_reset(&tk->delay_commit); no_log_delay_msg = 0; return 0; } tdiff = time_left(&tk->delay_commit); tk_log_debug("delay ticket commit for another " intfmt(tdiff)); if (!no_log_delay_msg) { tk_log_info("delaying ticket commit to CIB for " intfmt(tdiff)); tk_log_info("(or all sites are reached)"); no_log_delay_msg = 1; } return 1; } int ticket_write(struct ticket_config *tk) { if (local->type != SITE) return -EINVAL; if (ticket_dangerous(tk)) return 1; if (tk->leader == local) { if (tk->state != ST_LEADER) { tk_log_info("ticket state not yet consistent, " "delaying ticket grant to CIB"); return 1; } pcmk_handler.grant_ticket(tk); } else { pcmk_handler.revoke_ticket(tk); } tk->update_cib = 0; return 0; } void save_committed_tkt(struct ticket_config *tk) { if (!tk->last_valid_tk) { tk->last_valid_tk = malloc(sizeof(struct ticket_config)); if (!tk->last_valid_tk) { log_error("out of memory"); return; } } memcpy(tk->last_valid_tk, tk, sizeof(struct ticket_config)); } static void ext_prog_failed(struct ticket_config *tk, int start_election) { /* Give it to somebody else. * Just send a VOTE_FOR message, so the * others can start elections. */ if (leader_and_valid(tk)) { save_committed_tkt(tk); reset_ticket(tk); ticket_write(tk); if (start_election) { ticket_broadcast(tk, OP_VOTE_FOR, OP_REQ_VOTE, RLT_SUCCESS, OR_LOCAL_FAIL); } } } #define attr_found(geo_ap, ap) \ ((geo_ap) && !strcmp((geo_ap)->val, (ap)->attr_val)) int check_attr_prereq(struct ticket_config *tk, grant_type_e grant_type) { GList *el; struct attr_prereq *ap; struct geo_attr *geo_ap; for (el = g_list_first(tk->attr_prereqs); el; el = g_list_next(el)) { ap = (struct attr_prereq *)el->data; if (ap->grant_type != grant_type) continue; geo_ap = (struct geo_attr *)g_hash_table_lookup(tk->attr, ap->attr_name); switch(ap->op) { case ATTR_OP_EQ: if (!attr_found(geo_ap, ap)) goto fail; break; case ATTR_OP_NE: if (attr_found(geo_ap, ap)) goto fail; break; default: break; } } return 0; fail: tk_log_warn("'%s' attr-prereq failed", ap->attr_name); return 1; } /* do we need to run the external program? * or we already done that and waiting for the outcome * or program exited and we can collect the status * return codes * 0: no program defined * RUNCMD_MORE: program forked, results later * != 0: executing program failed (or some other failure) */ static int do_ext_prog(struct ticket_config *tk, int start_election) { int rv = 0; if (!tk_test.path) return 0; switch(tk_test.progstate) { case EXTPROG_IDLE: rv = run_handler(tk); if (rv == RUNCMD_ERR) { tk_log_warn("couldn't run external test, not allowed to acquire ticket"); ext_prog_failed(tk, start_election); } break; case EXTPROG_RUNNING: /* should never get here, but just in case */ rv = RUNCMD_MORE; break; case EXTPROG_EXITED: rv = tk_test_exit_status(tk); if (rv) { ext_prog_failed(tk, start_election); } break; case EXTPROG_IGNORE: /* nothing to do here */ break; } return rv; } /* Try to acquire a ticket * Could be manual grant or after start (if the ticket is granted * and still valid in the CIB) * If the external program needs to run, this is run twice, once * to start the program, and then to get the result and start * elections. */ int acquire_ticket(struct ticket_config *tk, cmd_reason_t reason) { int rv; if (reason == OR_ADMIN && check_attr_prereq(tk, GRANT_MANUAL)) return RLT_ATTR_PREREQ; switch(do_ext_prog(tk, 0)) { case 0: /* everything fine */ break; case RUNCMD_MORE: /* need to wait for the outcome before starting elections */ return 0; default: return RLT_EXT_FAILED; } rv = new_election(tk, local, 1, reason); return rv ? RLT_SYNC_FAIL : 0; } /** Try to get the ticket for the local site. * */ int do_grant_ticket(struct ticket_config *tk, int options) { int rv; tk_log_info("granting ticket"); if (tk->leader == local) return RLT_SUCCESS; if (is_owned(tk)) return RLT_OVERGRANT; set_future_time(&tk->delay_commit, tk->term_duration + tk->acquire_after); if (options & OPT_IMMEDIATE) { tk_log_warn("granting ticket immediately! If there are " "unreachable sites, _hope_ you are sure that they don't " "have the ticket!"); time_reset(&tk->delay_commit); } rv = acquire_ticket(tk, OR_ADMIN); if (rv) { time_reset(&tk->delay_commit); return rv; } else { return RLT_MORE; } } static void start_revoke_ticket(struct ticket_config *tk) { tk_log_info("revoking ticket"); save_committed_tkt(tk); reset_ticket(tk); set_leader(tk, no_leader); ticket_write(tk); ticket_broadcast(tk, OP_REVOKE, OP_ACK, RLT_SUCCESS, OR_ADMIN); } /** Ticket revoke. * Only to be started from the leader. */ int do_revoke_ticket(struct ticket_config *tk) { if (tk->acks_expected) { tk_log_info("delay ticket revoke until the current operation finishes"); set_next_state(tk, ST_INIT); return RLT_MORE; } else { start_revoke_ticket(tk); return RLT_SUCCESS; } } int list_ticket(char **pdata, unsigned int *len) { struct ticket_config *tk; char timeout_str[64]; char pending_str[64]; char *data, *cp; int i, alloc; time_t ts; *pdata = NULL; *len = 0; alloc = booth_conf->ticket_count * (BOOTH_NAME_LEN * 2 + 128); data = malloc(alloc); if (!data) return -ENOMEM; cp = data; foreach_ticket(i, tk) { if (is_time_set(&tk->term_expires)) { ts = wall_ts(&tk->term_expires); strftime(timeout_str, sizeof(timeout_str), "%F %T", localtime(&ts)); } else strcpy(timeout_str, "INF"); if (tk->leader == local && is_time_set(&tk->delay_commit) && !is_past(&tk->delay_commit)) { ts = wall_ts(&tk->delay_commit); strcpy(pending_str, " (commit pending until "); strftime(pending_str + strlen(" (commit pending until "), sizeof(pending_str) - strlen(" (commit pending until ") - 1, "%F %T", localtime(&ts)); strcat(pending_str, ")"); } else *pending_str = '\0'; cp += snprintf(cp, alloc - (cp - data), "ticket: %s, leader: %s", tk->name, ticket_leader_string(tk)); if (is_owned(tk)) { cp += snprintf(cp, alloc - (cp - data), ", expires: %s%s\n", timeout_str, pending_str); } else { cp += snprintf(cp, alloc - (cp - data), "\n"); } - if (alloc - (cp - data) <= 0) + if (alloc - (cp - data) <= 0) { + free(data); return -ENOMEM; + } } *pdata = data; *len = cp - data; return 0; } void disown_ticket(struct ticket_config *tk) { set_leader(tk, NULL); tk->is_granted = 0; get_time(&tk->term_expires); } int disown_if_expired(struct ticket_config *tk) { if (is_past(&tk->term_expires) || !tk->leader) { disown_ticket(tk); return 1; } return 0; } void reset_ticket(struct ticket_config *tk) { ignore_ext_test(tk); disown_ticket(tk); no_resends(tk); set_state(tk, ST_INIT); tk->voted_for = NULL; } static void log_reacquire_reason(struct ticket_config *tk) { int valid; const char *where_granted = "\0"; char buff[64]; valid = is_time_set(&tk->term_expires) && !is_past(&tk->term_expires); if (tk->leader == local) { where_granted = "granted here"; } else { snprintf(buff, sizeof(buff), "granted to %s", site_string(tk->leader)); where_granted = buff; } if (!valid) { tk_log_warn("%s, but not valid " "anymore (will try to reacquire)", where_granted); } if (tk->is_granted && tk->leader != local) { if (tk->leader && tk->leader != no_leader) { tk_log_error("granted here, but also %s, " "that's really too bad (will try to reacquire)", where_granted); } else { tk_log_warn("granted here, but we're " "not recorded as the grantee (will try to reacquire)"); } } } void update_ticket_state(struct ticket_config *tk, struct booth_site *sender) { if (tk->state == ST_CANDIDATE) { tk_log_info("learned from %s about " "newer ticket, stopping elections", site_string(sender)); /* there could be rejects coming from others; don't log * warnings unnecessarily */ tk->expect_more_rejects = 1; } if (tk->leader == local || tk->is_granted) { /* message from a live leader with valid ticket? */ if (sender == tk->leader && term_time_left(tk)) { if (tk->is_granted) { tk_log_warn("ticket was granted here, " "but it's live at %s (revoking here)", site_string(sender)); } else { tk_log_info("ticket live at %s", site_string(sender)); } disown_ticket(tk); ticket_write(tk); set_state(tk, ST_FOLLOWER); set_next_state(tk, ST_FOLLOWER); } else { if (tk->state == ST_CANDIDATE) { set_state(tk, ST_FOLLOWER); } set_next_state(tk, ST_LEADER); } } else { if (!tk->leader || tk->leader == no_leader) { if (sender) tk_log_info("ticket is not granted"); else tk_log_info("ticket is not granted (from CIB)"); set_state(tk, ST_INIT); } else { if (sender) tk_log_info("ticket granted to %s (says %s)", site_string(tk->leader), tk->leader == sender ? "they" : site_string(sender)); else tk_log_info("ticket granted to %s (from CIB)", site_string(tk->leader)); set_state(tk, ST_FOLLOWER); /* just make sure that we check the ticket soon */ set_next_state(tk, ST_FOLLOWER); } } } int setup_ticket(void) { struct ticket_config *tk; int i; foreach_ticket(i, tk) { reset_ticket(tk); if (local->type == SITE) { if (!pcmk_handler.load_ticket(tk)) { update_ticket_state(tk, NULL); } tk->update_cib = 1; } tk_log_info("broadcasting state query"); /* wait until all send their status (or the first * timeout) */ tk->start_postpone = 1; ticket_broadcast(tk, OP_STATUS, OP_MY_INDEX, RLT_SUCCESS, 0); } return 0; } int ticket_answer_list(int fd) { char *data; int rv; unsigned int olen; struct boothc_hdr_msg hdr; rv = list_ticket(&data, &olen); if (rv < 0) goto out; init_header(&hdr.header, CL_LIST, 0, 0, RLT_SUCCESS, 0, sizeof(hdr) + olen); rv = send_header_plus(fd, &hdr, data, olen); out: if (data) free(data); return rv; } int process_client_request(struct client *req_client, void *buf) { int rv, rc = 1; struct ticket_config *tk; int cmd; struct boothc_ticket_msg omsg; struct boothc_ticket_msg *msg; msg = (struct boothc_ticket_msg *)buf; cmd = ntohl(msg->header.cmd); if (!check_ticket(msg->ticket.id, &tk)) { log_warn("client referenced unknown ticket %s", msg->ticket.id); rv = RLT_INVALID_ARG; goto reply_now; } if ((cmd == CMD_GRANT) && is_owned(tk)) { log_warn("client wants to grant an (already granted!) ticket %s", msg->ticket.id); rv = RLT_OVERGRANT; goto reply_now; } if ((cmd == CMD_REVOKE) && !is_owned(tk)) { log_info("client wants to revoke a free ticket %s", msg->ticket.id); rv = RLT_TICKET_IDLE; goto reply_now; } if ((cmd == CMD_REVOKE) && tk->leader != local) { tk_log_info("not granted here, redirect to %s", ticket_leader_string(tk)); rv = RLT_REDIRECT; goto reply_now; } if (cmd == CMD_REVOKE) rv = do_revoke_ticket(tk); else rv = do_grant_ticket(tk, ntohl(msg->header.options)); if (rv == RLT_MORE) { /* client may receive further notifications, save the * request for further processing */ add_req(tk, req_client, msg); tk_log_debug("queue request %s for client %d", state_to_string(cmd), req_client->fd); rc = 0; /* we're not yet done with the message */ } reply_now: init_ticket_msg(&omsg, CL_RESULT, 0, rv, 0, tk); send_client_msg(req_client->fd, &omsg); return rc; } int notify_client(struct ticket_config *tk, int client_fd, struct boothc_ticket_msg *msg) { struct boothc_ticket_msg omsg; void (*deadfn) (int ci); int rv, rc, ci; int cmd, options; struct client *req_client; cmd = ntohl(msg->header.cmd); options = ntohl(msg->header.options); rv = tk->outcome; ci = find_client_by_fd(client_fd); if (ci < 0) { tk_log_info("client %d (request %s) left before being notified", client_fd, state_to_string(cmd)); return 0; } tk_log_debug("notifying client %d (request %s)", client_fd, state_to_string(cmd)); init_ticket_msg(&omsg, CL_RESULT, 0, rv, 0, tk); rc = send_client_msg(client_fd, &omsg); if (rc == 0 && ((rv == RLT_MORE) || (rv == RLT_CIB_PENDING && (options & OPT_WAIT_COMMIT)))) { /* more to do here, keep the request */ return 1; } else { /* we sent a definite answer or there was a write error, drop * the client */ if (rc) { tk_log_debug("failed to notify client %d (request %s)", client_fd, state_to_string(cmd)); } else { tk_log_debug("client %d (request %s) got final notification", client_fd, state_to_string(cmd)); } req_client = clients + ci; deadfn = req_client->deadfn; if(deadfn) { deadfn(ci); } return 0; /* we're done with this request */ } } int ticket_broadcast(struct ticket_config *tk, cmd_request_t cmd, cmd_request_t expected_reply, cmd_result_t res, cmd_reason_t reason) { struct boothc_ticket_msg msg; init_ticket_msg(&msg, cmd, 0, res, reason, tk); tk_log_debug("broadcasting '%s' (term=%d, valid=%d)", state_to_string(cmd), ntohl(msg.ticket.term), msg_term_time(&msg)); tk->last_request = cmd; if (expected_reply) { expect_replies(tk, expected_reply); } ticket_activate_timeout(tk); return transport()->broadcast_auth(&msg, sendmsglen(&msg)); } /* update the ticket on the leader, write it to the CIB, and send out the update message to others with the new expiry time */ int leader_update_ticket(struct ticket_config *tk) { int rv = 0, rv2; timetype now; if (tk->ticket_updated >= 2) return 0; if (tk->ticket_updated < 1) { tk->ticket_updated = 1; get_time(&now); copy_time(&now, &tk->last_renewal); set_future_time(&tk->term_expires, tk->term_duration); rv = ticket_broadcast(tk, OP_UPDATE, OP_ACK, RLT_SUCCESS, 0); } if (tk->ticket_updated < 2) { rv2 = ticket_write(tk); switch(rv2) { case 0: tk->ticket_updated = 2; tk->outcome = RLT_SUCCESS; foreach_tkt_req(tk, notify_client); break; case 1: if (tk->outcome != RLT_CIB_PENDING) { tk->outcome = RLT_CIB_PENDING; foreach_tkt_req(tk, notify_client); } break; default: break; } } return rv; } static void log_lost_servers(struct ticket_config *tk) { struct booth_site *n; int i; if (tk->retry_number > 1) /* log those that we couldn't reach, but do * that only on the first retry */ return; for (i = 0; i < booth_conf->site_count; i++) { n = booth_conf->site + i; if (!(tk->acks_received & n->bitmask)) { tk_log_warn("%s %s didn't acknowledge our %s, " "will retry %d times", (n->type == ARBITRATOR ? "arbitrator" : "site"), site_string(n), state_to_string(tk->last_request), tk->retries); } } } static void resend_msg(struct ticket_config *tk) { struct booth_site *n; int i; if (!(tk->acks_received ^ local->bitmask)) { ticket_broadcast(tk, tk->last_request, 0, RLT_SUCCESS, 0); } else { for (i = 0; i < booth_conf->site_count; i++) { n = booth_conf->site + i; if (!(tk->acks_received & n->bitmask)) { n->resend_cnt++; tk_log_debug("resending %s to %s", state_to_string(tk->last_request), site_string(n) ); send_msg(tk->last_request, tk, n, NULL); } } ticket_activate_timeout(tk); } } static void handle_resends(struct ticket_config *tk) { int ack_cnt; if (++tk->retry_number > tk->retries) { tk_log_info("giving up on sending retries"); no_resends(tk); set_ticket_wakeup(tk); return; } /* try to reach some sites again if we just stepped down */ if (tk->last_request == OP_VOTE_FOR) { tk_log_warn("no answers to our VtFr request to step down (try #%d), " "we are alone", tk->retry_number); goto just_resend; } if (!majority_of_bits(tk, tk->acks_received)) { ack_cnt = count_bits(tk->acks_received) - 1; if (!ack_cnt) { tk_log_warn("no answers to our request (try #%d), " "we are alone", tk->retry_number); } else { tk_log_warn("not enough answers to our request (try #%d): " "only got %d answers", tk->retry_number, ack_cnt); } } else { log_lost_servers(tk); } just_resend: resend_msg(tk); } int postpone_ticket_processing(struct ticket_config *tk) { extern timetype start_time; return tk->start_postpone && (-time_left(&start_time) < tk->timeout); } #define has_extprog_exited(tk) ((tk)->clu_test.progstate == EXTPROG_EXITED) static void process_next_state(struct ticket_config *tk) { int rv; switch(tk->next_state) { case ST_LEADER: if (has_extprog_exited(tk)) { if (tk->state != ST_LEADER) { rv = acquire_ticket(tk, OR_ADMIN); if (rv != 0) { /* external program failed */ tk->outcome = rv; foreach_tkt_req(tk, notify_client); } } } else { log_reacquire_reason(tk); acquire_ticket(tk, OR_REACQUIRE); } break; case ST_INIT: no_resends(tk); start_revoke_ticket(tk); tk->outcome = RLT_SUCCESS; foreach_tkt_req(tk, notify_client); break; /* wanting to be follower is not much of an ambition; no * processing, just return; don't reset start_postpone until * we got some replies to status */ case ST_FOLLOWER: return; default: break; } tk->start_postpone = 0; } static void ticket_lost(struct ticket_config *tk) { int reason = OR_TKT_LOST; if (tk->leader != local) { tk_log_warn("lost at %s", site_string(tk->leader)); } else { if (is_ext_prog_running(tk)) { ext_prog_timeout(tk); reason = OR_LOCAL_FAIL; } else { tk_log_warn("lost majority (revoking locally)"); reason = tk->election_reason ? tk->election_reason : OR_REACQUIRE; } } tk->lost_leader = tk->leader; save_committed_tkt(tk); reset_ticket(tk); set_state(tk, ST_FOLLOWER); if (local->type == SITE) { ticket_write(tk); schedule_election(tk, reason); } } static void next_action(struct ticket_config *tk) { int rv; switch(tk->state) { case ST_INIT: /* init state, handle resends for ticket revoke */ /* and rebroadcast if stepping down */ /* try to acquire ticket on grant */ if (has_extprog_exited(tk)) { rv = acquire_ticket(tk, OR_ADMIN); if (rv != 0) { /* external program failed */ tk->outcome = rv; foreach_tkt_req(tk, notify_client); } } else { if (tk->acks_expected) { handle_resends(tk); } } break; case ST_FOLLOWER: /* leader/ticket lost? and we didn't vote yet */ tk_log_debug("leader: %s, voted_for: %s", site_string(tk->leader), site_string(tk->voted_for)); if (!tk->leader) { if (!tk->voted_for || !tk->in_election) { disown_ticket(tk); if (!new_election(tk, NULL, 1, OR_AGAIN)) { ticket_activate_timeout(tk); } } else { /* we should restart elections in case nothing * happens in the meantime */ tk->in_election = 0; ticket_activate_timeout(tk); } } break; case ST_CANDIDATE: /* elections timed out? */ elections_end(tk); break; case ST_LEADER: /* timeout or ticket renewal? */ if (tk->acks_expected) { handle_resends(tk); if (majority_of_bits(tk, tk->acks_received)) { leader_update_ticket(tk); } } else { /* this is ticket renewal, run local test */ if (!do_ext_prog(tk, 1)) { ticket_broadcast(tk, OP_HEARTBEAT, OP_ACK, RLT_SUCCESS, 0); tk->ticket_updated = 0; } } break; default: break; } } static void ticket_cron(struct ticket_config *tk) { /* don't process the tickets too early after start */ if (postpone_ticket_processing(tk)) { tk_log_debug("ticket processing postponed (start_postpone=%d)", tk->start_postpone); /* but run again soon */ ticket_activate_timeout(tk); return; } /* no need for status resends, we hope we got at least one * my_index back */ if (tk->acks_expected == OP_MY_INDEX) { no_resends(tk); } /* after startup, we need to decide what to do based on the * current ticket state; tk->next_state has a hint * also used for revokes which had to be delayed */ if (tk->next_state) { process_next_state(tk); goto out; } /* Has an owner, has an expiry date, and expiry date in the past? * Losing the ticket must happen in _every_ state. */ if (is_owned(tk) && is_time_set(&tk->term_expires) && is_past(&tk->term_expires)) { ticket_lost(tk); goto out; } next_action(tk); out: tk->next_state = 0; if (!tk->in_election && tk->update_cib) ticket_write(tk); } void process_tickets(void) { struct ticket_config *tk; int i; timetype last_cron; foreach_ticket(i, tk) { if (!has_extprog_exited(tk) && is_time_set(&tk->next_cron) && !is_past(&tk->next_cron)) continue; tk_log_debug("ticket cron"); copy_time(&tk->next_cron, &last_cron); ticket_cron(tk); if (time_cmp(&last_cron, &tk->next_cron, ==)) { tk_log_debug("nobody set ticket wakeup"); set_ticket_wakeup(tk); } } } void tickets_log_info(void) { struct ticket_config *tk; int i; time_t ts; foreach_ticket(i, tk) { ts = wall_ts(&tk->term_expires); tk_log_info("state '%s' " "term %d " "leader %s " "expires %-24.24s", state_to_string(tk->state), tk->current_term, ticket_leader_string(tk), ctime(&ts)); } } static void update_acks( struct ticket_config *tk, struct booth_site *sender, struct booth_site *leader, struct boothc_ticket_msg *msg ) { uint32_t cmd; uint32_t req; cmd = ntohl(msg->header.cmd); req = ntohl(msg->header.request); if (req != tk->last_request || (tk->acks_expected != cmd && tk->acks_expected != OP_REJECTED)) return; /* got an ack! */ tk->acks_received |= sender->bitmask; if (all_replied(tk) || /* we just stepped down, need only one site to start * elections */ (cmd == OP_REQ_VOTE && tk->last_request == OP_VOTE_FOR)) { no_resends(tk); tk->start_postpone = 0; set_ticket_wakeup(tk); } } /* read ticket message */ int ticket_recv(void *buf, struct booth_site *source) { struct boothc_ticket_msg *msg; struct ticket_config *tk; struct booth_site *leader; uint32_t leader_u; msg = (struct boothc_ticket_msg *)buf; if (!check_ticket(msg->ticket.id, &tk)) { log_warn("got invalid ticket name %s from %s", msg->ticket.id, site_string(source)); source->invalid_cnt++; return -EINVAL; } leader_u = ntohl(msg->ticket.leader); if (!find_site_by_id(leader_u, &leader)) { tk_log_error("message with unknown leader %u received", leader_u); source->invalid_cnt++; return -EINVAL; } update_acks(tk, source, leader, msg); return raft_answer(tk, source, leader, msg); } static void log_next_wakeup(struct ticket_config *tk) { int left; left = time_left(&tk->next_cron); tk_log_debug("set ticket wakeup in " intfmt(left)); } /* New vote round; ยง5.2 */ /* delay the next election start for some random time * (up to 1 second) */ void add_random_delay(struct ticket_config *tk) { timetype tv; interval_add(&tk->next_cron, rand_time(min(1000, tk->timeout)), &tv); ticket_next_cron_at(tk, &tv); if (ANYDEBUG) { log_next_wakeup(tk); } } void set_ticket_wakeup(struct ticket_config *tk) { timetype near_future, tv, next_vote; /* At least every hour, perhaps sooner (default) */ ticket_next_cron_in(tk, 3600*TIME_RES); set_future_time(&near_future, 10); switch (tk->state) { case ST_LEADER: assert(tk->leader == local); get_next_election_time(tk, &next_vote); /* If timestamp is in the past, wakeup in * near future */ if (!is_time_set(&next_vote)) { tk_log_debug("next ts unset, wakeup soon"); ticket_next_cron_at(tk, &near_future); } else if (is_past(&next_vote)) { int tdiff = time_left(&next_vote); tk_log_debug("next ts in the past " intfmt(tdiff)); ticket_next_cron_at(tk, &near_future); } else { ticket_next_cron_at(tk, &next_vote); } break; case ST_CANDIDATE: assert(is_time_set(&tk->election_end)); ticket_next_cron_at(tk, &tk->election_end); break; case ST_INIT: case ST_FOLLOWER: /* If there is (or should be) some owner, check on it later on. * If no one is interested - don't care. */ if (is_owned(tk)) { interval_add(&tk->term_expires, tk->acquire_after, &tv); ticket_next_cron_at(tk, &tv); } break; default: tk_log_error("unknown ticket state: %d", tk->state); } if (tk->next_state) { /* we need to do something soon here */ if (!tk->acks_expected) { ticket_next_cron_at(tk, &near_future); } else { ticket_activate_timeout(tk); } } if (ANYDEBUG) { log_next_wakeup(tk); } } void schedule_election(struct ticket_config *tk, cmd_reason_t reason) { if (local->type != SITE) return; tk->election_reason = reason; get_time(&tk->next_cron); /* introduce a short delay before starting election */ add_random_delay(tk); } /* Given a state (in host byte order), return a human-readable (char*). * An array is used so that multiple states can be printed in a single printf(). */ char *state_to_string(uint32_t state_ho) { union mu { cmd_request_t s; char c[5]; }; static union mu cache[6] = { { 0 } }, *cur; static int current = 0; current ++; if (current >= sizeof(cache)/sizeof(cache[0])) current = 0; cur = cache + current; cur->s = htonl(state_ho); /* Shouldn't be necessary, union array is initialized with zeroes, and * these bytes never get written. */ cur->c[4] = 0; return cur->c; } int send_reject(struct booth_site *dest, struct ticket_config *tk, cmd_result_t code, struct boothc_ticket_msg *in_msg) { int req = ntohl(in_msg->header.cmd); struct boothc_ticket_msg msg; tk_log_debug("sending reject to %s", site_string(dest)); init_ticket_msg(&msg, OP_REJECTED, req, code, 0, tk); return booth_udp_send_auth(dest, &msg, sendmsglen(&msg)); } int send_msg ( int cmd, struct ticket_config *tk, struct booth_site *dest, struct boothc_ticket_msg *in_msg ) { int req = 0; struct ticket_config *valid_tk = tk; struct boothc_ticket_msg msg; /* if we want to send the last valid ticket, then if we're in * the ST_CANDIDATE state, the last valid ticket is in * tk->last_valid_tk */ if (cmd == OP_MY_INDEX) { if (tk->state == ST_CANDIDATE && tk->last_valid_tk) { valid_tk = tk->last_valid_tk; } tk_log_info("sending status to %s", site_string(dest)); } if (in_msg) req = ntohl(in_msg->header.cmd); init_ticket_msg(&msg, cmd, req, RLT_SUCCESS, 0, valid_tk); return booth_udp_send_auth(dest, &msg, sendmsglen(&msg)); }