/* * ntp_peer.c - management of data maintained for peer associations */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include "ntpd.h" #include "ntp_stdlib.h" /* * These routines manage the allocation of memory to peer structures * and the maintenance of the peer hash table. The two main entry * points are findpeer(), which looks for corresponding peer data * in the peer list, newpeer(), which allocates a new peer structure * and adds it to the list, and unpeer(), which demobilizes the association * and deallocates the structure. */ /* * The peer hash table (imported by the protocol module). */ struct peer *peer_hash[HASH_SIZE]; int peer_hash_count[HASH_SIZE]; /* count of peers in each bucket */ /* * The association ID hash table. Used for lookups by association ID */ struct peer *assoc_hash[HASH_SIZE]; int assoc_hash_count[HASH_SIZE]; /* * The free list. Clean structures only, please. */ struct peer *peer_free; int peer_free_count; /* * Association ID. We initialize this value randomly, the assign a new * value every time the peer structure is incremented. */ u_short current_association_ID; /* * Memory allocation watermarks. */ #define INIT_PEER_ALLOC 15 /* initialize space for 15 peers */ #define INC_PEER_ALLOC 5 /* when we run out, add 5 more */ /* * Miscellaneous statistic counters which may be queried. */ u_long peer_timereset; /* time stat counters were zeroed */ u_long findpeer_calls; /* number of calls to findpeer */ u_long assocpeer_calls; /* number of calls to findpeerbyassoc */ u_long peer_allocations; /* number of allocations from the free list */ u_long peer_demobilizations; /* number of structs freed to free list */ int total_peer_structs; /* number of peer structs in circulation */ /* * default interface. Imported from the io module. */ extern struct interface *any_interface; /* * Timer queue and current time. Imported from the timer module. */ extern u_long current_time; extern struct event timerqueue[]; /* * Our initial allocation of peer space */ static struct peer init_peer_alloc[INIT_PEER_ALLOC]; /* * Initialization data. When configuring peers at initialization time, * we try to get their poll update timers initialized to different values * to prevent us from sending big clumps of data all at once. */ u_long init_peer_starttime; extern int initializing; extern int debug; static void getmorepeermem P((void)); /* * init_peer - initialize peer data structures and counters * * N.B. We use the random number routine in here. It had better be * initialized prior to getting here. */ void init_peer() { register int i; /* * Clear hash table and counters. */ for (i = 0; i < HASH_SIZE; i++) { peer_hash[i] = 0; peer_hash_count[i] = 0; assoc_hash[i] = 0; assoc_hash_count[i] = 0; } /* * Clear stat counters */ findpeer_calls = peer_allocations = 0; assocpeer_calls = peer_demobilizations = 0; /* * Initialization counter. */ init_peer_starttime = 0; /* * Initialize peer memory. */ peer_free = 0; for (i = 0; i < INIT_PEER_ALLOC; i++) { init_peer_alloc[i].next = peer_free; peer_free = &init_peer_alloc[i]; } total_peer_structs = INIT_PEER_ALLOC; peer_free_count = INIT_PEER_ALLOC; /* * Initialize our first association ID */ current_association_ID = (u_short)ranp2(16); if (current_association_ID == 0) current_association_ID = 1; } /* * getmorepeermem - add more peer structures to the free list */ static void getmorepeermem() { register int i; register struct peer *peer; peer = (struct peer *)emalloc(INC_PEER_ALLOC*sizeof(struct peer)); for (i = 0; i < INC_PEER_ALLOC; i++) { peer->next = peer_free; peer_free = peer; peer++; } total_peer_structs += INC_PEER_ALLOC; peer_free_count += INC_PEER_ALLOC; } /* * findexistingpeer - return a pointer to a peer in the hash table */ struct peer * findexistingpeer(addr, start_peer) struct sockaddr_in *addr; struct peer *start_peer; { register struct peer *peer; /* * start_peer is included so we can locate instances of the * same peer through different interfaces in the hash table. */ if (start_peer == 0) peer = peer_hash[HASH_ADDR(addr)]; else peer = start_peer->next; while (peer != 0) { if (NSRCADR(addr) == NSRCADR(&peer->srcadr) && NSRCPORT(addr) == NSRCPORT(&peer->srcadr)) return peer; peer = peer->next; } return (struct peer *)0; } /* * findpeer - find and return a peer in the hash table. */ struct peer * findpeer(srcadr, dstadr, fd) struct sockaddr_in *srcadr; struct interface *dstadr; int fd; { register struct peer *any_inter_peer; register struct peer *peer; register struct peer *best = (struct peer *) 0; int hash; findpeer_calls++; any_inter_peer = 0; hash = HASH_ADDR(srcadr); for (peer = peer_hash[hash]; peer != 0; peer = peer->next) { if (NSRCADR(srcadr) == NSRCADR(&peer->srcadr) && NSRCPORT(srcadr) == NSRCPORT(&peer->srcadr)) { if (peer->dstadr == dstadr) { int rfd = (peer->cast_flags & MDF_BCAST) ? dstadr->bfd : dstadr->fd; if (rfd == fd) return peer; /* got it! */ best = peer; } if (peer->dstadr == any_interface) { /* * We shouldn't have more than one * instance of the peer in the table, * but I don't trust this. Save this * one for later and continue search. */ if (any_inter_peer == 0) any_inter_peer = peer; else msyslog(LOG_ERR, "two instances of default interface for %s in hash table", ntoa(srcadr)); } /* * Multicast hacks to determine peer when a * packet arrives and there exists an assoc. * with src in client/server mode */ if (((dstadr == any_interface) || (peer->cast_flags & MDF_MCAST)) && peer->flags & FLAG_MCAST2) return peer; } } if(best) { return best; } /* * If we didn't find the specific peer but found a wild card, * modify the interface and return him. */ if (any_inter_peer != 0) { any_inter_peer->dstadr = dstadr; return any_inter_peer; } /* * Out of luck. Return 0. */ return (struct peer *)0; } /* * findpeerbyassocid - find and return a peer using his association ID */ struct peer * findpeerbyassoc(assoc) int assoc; { register struct peer *peer; int hash; assocpeer_calls++; hash = assoc & HASH_MASK; for (peer = assoc_hash[hash]; peer != 0; peer = peer->ass_next) { if ((u_short)assoc == peer->associd) return peer; /* got it! */ } /* * Out of luck. Return 0. */ return (struct peer *)0; } /* * unpeer - remove peer structure from hash table and free structure */ void unpeer(peer_to_remove) struct peer *peer_to_remove; { int hash; hash = HASH_ADDR(&peer_to_remove->srcadr); peer_hash_count[hash]--; peer_demobilizations++; #ifdef REFCLOCK /* * If this peer is actually a clock, shut it down first */ if (peer_to_remove->flags & FLAG_REFCLOCK) refclock_unpeer(peer_to_remove); #endif if (peer_hash[hash] == peer_to_remove) peer_hash[hash] = peer_to_remove->next; else { register struct peer *peer; peer = peer_hash[hash]; while (peer != 0 && peer->next != peer_to_remove) peer = peer->next; if (peer == 0) { peer_hash_count[hash]++; msyslog(LOG_ERR, "peer struct for %s not in table!", ntoa(&peer->srcadr)); } else { peer->next = peer_to_remove->next; } } /* * Remove him from the association hash as well. */ hash = peer_to_remove->associd & HASH_MASK; assoc_hash_count[hash]--; if (assoc_hash[hash] == peer_to_remove) assoc_hash[hash] = peer_to_remove->ass_next; else { register struct peer *peer; peer = assoc_hash[hash]; while (peer != 0 && peer->ass_next != peer_to_remove) peer = peer->ass_next; if (peer == 0) { assoc_hash_count[hash]++; msyslog(LOG_ERR, "peer struct for %s not in association table!", ntoa(&peer->srcadr)); } else { peer->ass_next = peer_to_remove->ass_next; } } TIMER_DEQUEUE(&peer_to_remove->event_timer); peer_to_remove->next = peer_free; peer_free = peer_to_remove; peer_free_count++; } /* * peer_config - configure a new peer */ struct peer * peer_config(srcadr, dstadr, hmode, version, minpoll, maxpoll, flags, ttl, key) struct sockaddr_in *srcadr; struct interface *dstadr; int hmode; int version; int minpoll; int maxpoll; int flags; int ttl; u_int32 key; { register struct peer *peer; #ifdef DEBUG if (debug) printf("peer_config: addr %s mode %d version %d minpoll %d maxpoll %d flags %d ttl %d key %lu\n", ntoa(srcadr), hmode, version, minpoll, maxpoll, flags, ttl, (u_long)key); #endif /* * See if we have this guy in the tables already. If * so just mark him configured. */ peer = findexistingpeer(srcadr, (struct peer *)0); if (dstadr != 0) { while (peer != 0) { if (peer->dstadr == dstadr) break; peer = findexistingpeer(srcadr, peer); } } /* * Torque the flags to make sure they're valid */ flags &= (FLAG_AUTHENABLE|FLAG_PREFER); /* * If we found one, just change his mode and mark him configured. */ if (peer != 0) { peer->hmode = (u_char)hmode; peer->version = (u_char)version; peer->minpoll = (u_char)minpoll; peer->maxpoll = (u_char)maxpoll; peer->hpoll = peer->minpoll; peer->ppoll = peer->minpoll; peer->flags = ((u_char)(flags | FLAG_CONFIG)) | (peer->flags & FLAG_REFCLOCK); peer->cast_flags = (hmode == MODE_BROADCAST) ? IN_CLASSD(ntohl(srcadr->sin_addr.s_addr)) ? MDF_MCAST : MDF_BCAST : MDF_UCAST; peer->ttl = (u_char)ttl; peer->keyid = key; return peer; } /* * If we're here this guy is unknown to us. Make a new peer * structure for him. */ peer = newpeer(srcadr, dstadr, hmode, version, minpoll, maxpoll, ttl, key); if (peer != 0) peer->flags |= (u_char)(flags|FLAG_CONFIG); return peer; } /* * newpeer - initialize a new peer association */ struct peer * newpeer(srcadr, dstadr, hmode, version, minpoll, maxpoll, ttl, key) struct sockaddr_in *srcadr; struct interface *dstadr; int hmode; int version; int minpoll; int maxpoll; int ttl; u_int32 key; { register struct peer *peer; register int i; /* * Some dirt here. Some of the initialization requires * knowlege of our system state. */ extern s_fp sys_bdelay; extern long sys_clock; if (peer_free_count == 0) getmorepeermem(); peer = peer_free; peer_free = peer->next; peer_free_count--; /* * Initialize the structure. This stuff is sort of part of * the receive procedure and part of the clear procedure rolled * into one. * * Zero the whole thing for now. We might be pickier later. */ memset((char *)peer, 0, sizeof(struct peer)); peer->srcadr = *srcadr; if (dstadr != 0) peer->dstadr = dstadr; else if (hmode == MODE_BROADCAST) peer->dstadr = findbcastinter(srcadr); else peer->dstadr = any_interface; peer->cast_flags = (hmode == MODE_BROADCAST) ? (IN_CLASSD(ntohl(srcadr->sin_addr.s_addr))) ? MDF_MCAST : MDF_BCAST : (hmode == MODE_BCLIENT || hmode == MODE_MCLIENT) ? (peer->dstadr->flags & INT_MULTICAST) ? MDF_MCAST : MDF_BCAST : MDF_UCAST; peer->hmode = (u_char)hmode; peer->version = (u_char)version; peer->minpoll = (u_char)minpoll; peer->maxpoll = (u_char)maxpoll; peer->hpoll = peer->minpoll; peer->ppoll = peer->minpoll; peer->ttl = ttl; peer->keyid = key; peer->estbdelay = sys_bdelay; peer->leap = LEAP_NOTINSYNC; peer->precision = DEFPRECISION; peer->dispersion = NTP_MAXDISPERSE; peer->stratum = STRATUM_UNSPEC; peer->update = sys_clock; for (i = 0; i < NTP_SHIFT; i++) { peer->filter_order[i] = i; peer->filter_error[i] = NTP_MAXDISPERSE; } /* * Assign him an association ID and increment the system variable */ peer->associd = current_association_ID; if (++current_association_ID == 0) ++current_association_ID; /* * Note time on statistics timers. */ peer->timereset = current_time; peer->timereachable = current_time; peer->timereceived = current_time; #ifdef REFCLOCK if (ISREFCLOCKADR(&peer->srcadr)) { /* * We let the reference clock support do clock * dependent initialization. This includes setting * the peer timer, since the clock may have requirements * for this. */ if (!refclock_newpeer(peer)) { /* * Dump it, something screwed up */ peer->next = peer_free; peer_free = peer; peer_free_count++; return 0; } } else { #endif /* * Set up timer. If initializing, just make sure we start polling * in different 4 second intervals. */ peer->event_timer.peer = peer; peer->event_timer.event_handler = transmit; if (initializing) { init_peer_starttime += (1 << EVENT_TIMEOUT); if (init_peer_starttime >= (u_long)(1 << peer->minpoll)) init_peer_starttime = (1 << EVENT_TIMEOUT); peer->event_timer.event_time = init_peer_starttime; } else { /* * First expiry is set to eight seconds from now. */ peer->event_timer.event_time = (1 << (peer->minpoll - 1)) + current_time; } TIMER_ENQUEUE(timerqueue, &peer->event_timer); #ifdef REFCLOCK } #endif /* * Put him in the hash tables. */ i = HASH_ADDR(&peer->srcadr); peer->next = peer_hash[i]; peer_hash[i] = peer; peer_hash_count[i]++; i = peer->associd & HASH_MASK; peer->ass_next = assoc_hash[i]; assoc_hash[i] = peer; assoc_hash_count[i]++; return peer; } /* * peer_unconfig - remove the configuration bit from a peer */ int peer_unconfig(srcadr, dstadr) struct sockaddr_in *srcadr; struct interface *dstadr; { register struct peer *peer; int num_found; num_found = 0; peer = findexistingpeer(srcadr, (struct peer *)0); while (peer != 0) { if (peer->flags & FLAG_CONFIG && (dstadr == 0 || peer->dstadr == dstadr)) { num_found++; /* * Tricky stuff here. If the peer is polling us * in active mode, turn off the configuration bit * and make the mode passive. This allows us to * avoid dumping a lot of history for peers we * might choose to keep track of in passive mode. * The protocol will eventually terminate undesirables * on its own. */ if (peer->hmode == MODE_ACTIVE && peer->pmode == MODE_ACTIVE) { peer->hmode = MODE_PASSIVE; peer->flags &= ~FLAG_CONFIG; } else { unpeer(peer); peer = 0; } } peer = findexistingpeer(srcadr, peer); } return num_found; } /* * peer_clr_stats - clear peer module stat counters */ void peer_clr_stats() { findpeer_calls = 0; assocpeer_calls = 0; peer_allocations = 0; peer_demobilizations = 0; peer_timereset = current_time; } /* * peer_reset - reset stat counters in a peer structure */ void peer_reset(peer) struct peer *peer; { if (peer == 0) return; peer->sent = 0; peer->received = 0; peer->processed = 0; peer->badauth = 0; peer->bogusorg = 0; peer->oldpkt = 0; peer->seldisptoolarge = 0; peer->selbroken = 0; peer->seltooold = 0; peer->timereset = current_time; } /* * peer_all_reset - reset all peer stat counters */ void peer_all_reset() { struct peer *peer; int hash; for (hash = 0; hash < HASH_SIZE; hash++) for (peer = peer_hash[hash]; peer != 0; peer = peer->next) peer_reset(peer); }