Commit 1123e707 authored by Ondřej Zajíček's avatar Ondřej Zajíček

Implements token bucket filter for rate limiting.

parent dcde7ae5
......@@ -493,7 +493,7 @@ f_rta_cow(void)
}
}
static struct rate_limit rl_runtime_err;
static struct tbf rl_runtime_err = TBF_DEFAULT_LOG_LIMITS;
#define runtime(x) do { \
log_rl(&rl_runtime_err, L_ERR "filters, line %d: %s", what->lineno, x); \
......@@ -1492,7 +1492,7 @@ f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struc
if (res.type != T_RETURN) {
log( L_ERR "Filter %s did not return accept nor reject. Make up your mind", filter->name);
log_rl(&rl_runtime_err, L_ERR "Filter %s did not return accept nor reject. Make up your mind", filter->name);
return F_ERROR;
}
DBG( "done (%u)\n", res.val.i );
......
H Library functions
S ip.c ipv4.c ipv6.c
S lists.c
S checksum.c bitops.c patmatch.c printf.c xmalloc.c
S checksum.c bitops.c patmatch.c printf.c xmalloc.c tbf.c
D resource.sgml
S resource.c
S mempool.c
......
......@@ -19,6 +19,7 @@ resource.c
resource.h
slab.c
socket.h
tbf.c
unaligned.h
xmalloc.c
printf.c
......
......@@ -68,6 +68,38 @@ typedef s64 btime;
#endif
/* Rate limiting */
struct tbf {
bird_clock_t timestamp; /* Last update */
u16 count; /* Available tokens */
u16 burst; /* Max number of tokens */
u16 rate; /* Rate of replenishment */
u16 mark; /* Whether last op was limited */
};
/* Default TBF values for rate limiting log messages */
#define TBF_DEFAULT_LOG_LIMITS { .rate = 1, .burst = 5 }
void tbf_update(struct tbf *f);
static inline int
tbf_limit(struct tbf *f)
{
tbf_update(f);
if (!f->count)
{
f->mark = 1;
return 1;
}
f->count--;
f->mark = 0;
return 0;
}
/* Logging and dying */
typedef struct buffer {
......@@ -88,16 +120,10 @@ typedef struct buffer {
#define LOG_BUFFER_SIZE 1024
struct rate_limit {
bird_clock_t timestamp;
int count;
};
#define log log_msg
void log_commit(int class, buffer *buf);
void log_msg(char *msg, ...);
void log_rl(struct rate_limit *rl, char *msg, ...);
void log_rl(struct tbf *rl, char *msg, ...);
void die(char *msg, ...) NORET;
void bug(char *msg, ...) NORET;
......
/*
* BIRD Library -- Token Bucket Filter
*
* (c) 2014 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2014 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "nest/bird.h"
void
tbf_update(struct tbf *f)
{
bird_clock_t delta = now - f->timestamp;
if (delta == 0)
return;
f->timestamp = now;
if ((0 < delta) && (delta < f->burst))
{
u32 next = f->count + delta * f->rate;
f->count = MIN(next, f->burst);
}
else
f->count = f->burst;
}
......@@ -645,7 +645,7 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
struct proto *p = ah->proto;
struct rtable *table = ah->table;
struct proto_stats *stats = ah->stats;
static struct rate_limit rl_pipe;
static struct tbf rl_pipe = TBF_DEFAULT_LOG_LIMITS;
rte *before_old = NULL;
rte *old_best = net->routes;
rte *old = NULL;
......@@ -1367,7 +1367,7 @@ rt_init(void)
static int
rt_prune_step(rtable *tab, int step, int *limit)
{
static struct rate_limit rl_flush;
static struct tbf rl_flush = TBF_DEFAULT_LOG_LIMITS;
struct fib_iterator *fit = &tab->prune_fit;
DBG("Pruning route table %s\n", tab->name);
......
......@@ -22,7 +22,8 @@
#include "bgp.h"
static struct rate_limit rl_rcv_update, rl_snd_update;
static struct tbf rl_rcv_update = TBF_DEFAULT_LOG_LIMITS;
static struct tbf rl_snd_update = TBF_DEFAULT_LOG_LIMITS;
/* Table for state -> RFC 6608 FSM error subcodes */
static byte fsm_err_subcode[BS_MAX] = {
......
......@@ -151,7 +151,7 @@ nl_get_reply(struct nl_sock *nl)
}
}
static struct rate_limit rl_netlink_err;
static struct tbf rl_netlink_err = TBF_DEFAULT_LOG_LIMITS;
static int
nl_error(struct nlmsghdr *h)
......
......@@ -300,10 +300,10 @@ krt_trace_in(struct krt_proto *p, rte *e, char *msg)
}
static inline void
krt_trace_in_rl(struct rate_limit *rl, struct krt_proto *p, rte *e, char *msg)
krt_trace_in_rl(struct tbf *f, struct krt_proto *p, rte *e, char *msg)
{
if (p->p.debug & D_PACKETS)
log_rl(rl, L_TRACE "%s: %I/%d: %s", p->p.name, e->net->n.prefix, e->net->n.pxlen, msg);
log_rl(f, L_TRACE "%s: %I/%d: %s", p->p.name, e->net->n.prefix, e->net->n.pxlen, msg);
}
/*
......@@ -312,7 +312,7 @@ krt_trace_in_rl(struct rate_limit *rl, struct krt_proto *p, rte *e, char *msg)
#ifdef KRT_ALLOW_LEARN
static struct rate_limit rl_alien_seen, rl_alien_updated, rl_alien_created, rl_alien_ignored;
static struct tbf rl_alien = TBF_DEFAULT_LOG_LIMITS;
/*
* krt_same_key() specifies what (aside from the net) is the key in
......@@ -378,20 +378,20 @@ krt_learn_scan(struct krt_proto *p, rte *e)
{
if (krt_uptodate(m, e))
{
krt_trace_in_rl(&rl_alien_seen, p, e, "[alien] seen");
krt_trace_in_rl(&rl_alien, p, e, "[alien] seen");
rte_free(e);
m->u.krt.seen = 1;
}
else
{
krt_trace_in_rl(&rl_alien_updated, p, e, "[alien] updated");
krt_trace_in(p, e, "[alien] updated");
*mm = m->next;
rte_free(m);
m = NULL;
}
}
else
krt_trace_in_rl(&rl_alien_created, p, e, "[alien] created");
krt_trace_in(p, e, "[alien] created");
if (!m)
{
e->next = n->routes;
......@@ -637,7 +637,7 @@ krt_got_route(struct krt_proto *p, rte *e)
krt_learn_scan(p, e);
else
{
krt_trace_in_rl(&rl_alien_ignored, p, e, "[alien] ignored");
krt_trace_in_rl(&rl_alien, p, e, "[alien] ignored");
rte_free(e);
}
return;
......
......@@ -32,9 +32,6 @@ static FILE *dbgf;
static list *current_log_list;
static char *current_syslog_name; /* NULL -> syslog closed */
static const bird_clock_t rate_limit_time = 5;
static const int rate_limit_count = 5;
#ifdef USE_PTHREADS
......@@ -154,7 +151,6 @@ vlog(int class, const char *msg, va_list args)
}
/**
* log - log a message
* @msg: printf-like formatting string with message class information
......@@ -180,31 +176,21 @@ log_msg(char *msg, ...)
}
void
log_rl(struct rate_limit *rl, char *msg, ...)
log_rl(struct tbf *f, char *msg, ...)
{
int last_hit = f->mark;
int class = 1;
va_list args;
bird_clock_t delta = now - rl->timestamp;
if ((0 <= delta) && (delta < rate_limit_time))
{
rl->count++;
}
else
{
rl->timestamp = now;
rl->count = 1;
}
if (rl->count > rate_limit_count)
/* Rate limiting is a bit tricky here as it also logs '...' during the first hit */
if (tbf_limit(f) && last_hit)
return;
va_start(args, msg);
if (*msg >= 1 && *msg <= 8)
class = *msg++;
vlog(class, msg, args);
if (rl->count == rate_limit_count)
vlog(class, "...", args);
va_start(args, msg);
vlog(class, (f->mark ? "..." : msg), args);
va_end(args);
}
......
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