diff options
Diffstat (limited to 'ntpd/ntp_monitor.c')
-rw-r--r-- | ntpd/ntp_monitor.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/ntpd/ntp_monitor.c b/ntpd/ntp_monitor.c new file mode 100644 index 0000000..6b288fc --- /dev/null +++ b/ntpd/ntp_monitor.c @@ -0,0 +1,335 @@ +/* + * ntp_monitor - monitor ntpd statistics + */ +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include "ntpd.h" +#include "ntp_io.h" +#include "ntp_if.h" +#include "ntp_stdlib.h" + +#include <stdio.h> +#include <signal.h> +#ifdef HAVE_SYS_IOCTL_H +# include <sys/ioctl.h> +#endif + +/* + * I'm still not sure I like what I've done here. It certainly consumes + * memory like it is going out of style, and also may not be as low + * overhead as I'd imagined. + * + * Anyway, we record statistics based on source address, mode and + * version (for now, anyway. Check the code). The receive procedure + * calls us with the incoming rbufp before it does anything else. + * + * Each entry is doubly linked into two lists, a hash table and a + * most-recently-used list. When a packet arrives it is looked up in + * the hash table. If found, the statistics are updated and the entry + * relinked at the head of the MRU list. If not found, a new entry is + * allocated, initialized and linked into both the hash table and at the + * head of the MRU list. + * + * Memory is usually allocated by grabbing a big chunk of new memory and + * cutting it up into littler pieces. The exception to this when we hit + * the memory limit. Then we free memory by grabbing entries off the + * tail for the MRU list, unlinking from the hash table, and + * reinitializing. + * + * trimmed back memory consumption ... jdg 8/94 + */ +/* + * Limits on the number of structures allocated. This limit is picked + * with the illicit knowlege that we can only return somewhat less + * than 8K bytes in a mode 7 response packet, and that each structure + * will require about 20 bytes of space in the response. + * + * ... I don't believe the above is true anymore ... jdg + */ +#ifndef MAXMONMEM +#define MAXMONMEM 600 /* we allocate up to 600 structures */ +#endif +#ifndef MONMEMINC +#define MONMEMINC 40 /* allocate them 40 at a time */ +#endif + +/* + * Hashing stuff + */ +#define MON_HASH_SIZE 128 +#define MON_HASH_MASK (MON_HASH_SIZE-1) +#define MON_HASH(addr) sock_hash(addr) + +/* + * Pointers to the hash table, the MRU list and the count table. Memory + * for the hash and count tables is only allocated if monitoring is + * turned on. + */ +static struct mon_data *mon_hash[MON_HASH_SIZE]; /* list ptrs */ +struct mon_data mon_mru_list; + +/* + * List of free structures structures, and counters of free and total + * structures. The free structures are linked with the hash_next field. + */ +static struct mon_data *mon_free; /* free list or null if none */ +static int mon_total_mem; /* total structures allocated */ +static int mon_mem_increments; /* times called malloc() */ + +/* + * Initialization state. We may be monitoring, we may not. If + * we aren't, we may not even have allocated any memory yet. + */ +int mon_enabled; /* enable switch */ +u_long mon_age = 3000; /* preemption limit */ +static int mon_have_memory; +static void mon_getmoremem P((void)); +static void remove_from_hash P((struct mon_data *)); + +/* + * init_mon - initialize monitoring global data + */ +void +init_mon(void) +{ + /* + * Don't do much of anything here. We don't allocate memory + * until someone explicitly starts us. + */ + mon_enabled = MON_OFF; + mon_have_memory = 0; + + mon_total_mem = 0; + mon_mem_increments = 0; + mon_free = NULL; + memset(&mon_hash[0], 0, sizeof mon_hash); + memset(&mon_mru_list, 0, sizeof mon_mru_list); +} + + +/* + * mon_start - start up the monitoring software + */ +void +mon_start( + int mode + ) +{ + + if (mon_enabled != MON_OFF) { + mon_enabled |= mode; + return; + } + if (mode == MON_OFF) + return; + + if (!mon_have_memory) { + mon_total_mem = 0; + mon_mem_increments = 0; + mon_free = NULL; + mon_getmoremem(); + mon_have_memory = 1; + } + + mon_mru_list.mru_next = &mon_mru_list; + mon_mru_list.mru_prev = &mon_mru_list; + mon_enabled = mode; +} + + +/* + * mon_stop - stop the monitoring software + */ +void +mon_stop( + int mode + ) +{ + register struct mon_data *md, *md_next; + register int i; + + if (mon_enabled == MON_OFF) + return; + if ((mon_enabled & mode) == 0 || mode == MON_OFF) + return; + + mon_enabled &= ~mode; + if (mon_enabled != MON_OFF) + return; + + /* + * Put everything back on the free list + */ + for (i = 0; i < MON_HASH_SIZE; i++) { + md = mon_hash[i]; /* get next list */ + mon_hash[i] = NULL; /* zero the list head */ + while (md != NULL) { + md_next = md->hash_next; + md->hash_next = mon_free; + mon_free = md; + md = md_next; + } + } + + mon_mru_list.mru_next = &mon_mru_list; + mon_mru_list.mru_prev = &mon_mru_list; +} + + +/* + * ntp_monitor - record stats about this packet + */ +void +ntp_monitor( + struct recvbuf *rbufp + ) +{ + register struct pkt *pkt; + register struct mon_data *md; + struct sockaddr_storage addr; + register int hash; + register int mode; + + if (mon_enabled == MON_OFF) + return; + + pkt = &rbufp->recv_pkt; + memset(&addr, 0, sizeof(addr)); + memcpy(&addr, &(rbufp->recv_srcadr), sizeof(addr)); + hash = MON_HASH(&addr); + mode = PKT_MODE(pkt->li_vn_mode); + md = mon_hash[hash]; + while (md != NULL) { + + /* + * Match address only to conserve MRU size. + */ + if (SOCKCMP(&md->rmtadr, &addr)) { + md->drop_count = current_time - md->lasttime; + md->lasttime = current_time; + md->count++; + md->rmtport = NSRCPORT(&rbufp->recv_srcadr); + md->mode = (u_char) mode; + md->version = PKT_VERSION(pkt->li_vn_mode); + + /* + * Shuffle to the head of the MRU list. + */ + md->mru_next->mru_prev = md->mru_prev; + md->mru_prev->mru_next = md->mru_next; + md->mru_next = mon_mru_list.mru_next; + md->mru_prev = &mon_mru_list; + mon_mru_list.mru_next->mru_prev = md; + mon_mru_list.mru_next = md; + return; + } + md = md->hash_next; + } + + /* + * If we got here, this is the first we've heard of this + * guy. Get him some memory, either from the free list + * or from the tail of the MRU list. + */ + if (mon_free == NULL && mon_total_mem >= MAXMONMEM) { + + /* + * Preempt from the MRU list if old enough. + */ + md = mon_mru_list.mru_prev; + if (((u_long)RANDOM & 0xffffffff) / FRAC > + (double)(current_time - md->lasttime) / mon_age) + return; + + md->mru_prev->mru_next = &mon_mru_list; + mon_mru_list.mru_prev = md->mru_prev; + remove_from_hash(md); + } else { + if (mon_free == NULL) + mon_getmoremem(); + md = mon_free; + mon_free = md->hash_next; + } + + /* + * Got one, initialize it + */ + md->avg_interval = 0; + md->lasttime = current_time; + md->count = 1; + md->drop_count = 0; + memset(&md->rmtadr, 0, sizeof(md->rmtadr)); + memcpy(&md->rmtadr, &addr, sizeof(addr)); + md->rmtport = NSRCPORT(&rbufp->recv_srcadr); + md->mode = (u_char) mode; + md->version = PKT_VERSION(pkt->li_vn_mode); + md->interface = rbufp->dstadr; + md->cast_flags = (u_char)(((rbufp->dstadr->flags & INT_MULTICAST) && + rbufp->fd == md->interface->fd) ? MDF_MCAST: rbufp->fd == + md->interface->bfd ? MDF_BCAST : MDF_UCAST); + + /* + * Drop him into front of the hash table. Also put him on top of + * the MRU list. + */ + md->hash_next = mon_hash[hash]; + mon_hash[hash] = md; + md->mru_next = mon_mru_list.mru_next; + md->mru_prev = &mon_mru_list; + mon_mru_list.mru_next->mru_prev = md; + mon_mru_list.mru_next = md; +} + + +/* + * mon_getmoremem - get more memory and put it on the free list + */ +static void +mon_getmoremem(void) +{ + register struct mon_data *md; + register int i; + struct mon_data *freedata; /* 'old' free list (null) */ + + md = (struct mon_data *)emalloc(MONMEMINC * + sizeof(struct mon_data)); + freedata = mon_free; + mon_free = md; + for (i = 0; i < (MONMEMINC-1); i++) { + md->hash_next = (md + 1); + md++; + } + + /* + * md now points at the last. Link in the rest of the chain. + */ + md->hash_next = freedata; + mon_total_mem += MONMEMINC; + mon_mem_increments++; +} + +static void +remove_from_hash( + struct mon_data *md + ) +{ + register int hash; + register struct mon_data *md_prev; + + hash = MON_HASH(&md->rmtadr); + if (mon_hash[hash] == md) { + mon_hash[hash] = md->hash_next; + } else { + md_prev = mon_hash[hash]; + while (md_prev->hash_next != md) { + md_prev = md_prev->hash_next; + if (md_prev == NULL) { + /* logic error */ + return; + } + } + md_prev->hash_next = md->hash_next; + } +} |