linux/include/trace/events/fib.h
Steven Rostedt (Google) fca8300f68 tracing/ipv4/ipv6: Use static array for name field in fib*_lookup_table event
The fib_lookup_table and fib6_lookup_table events declare name as a
dynamic_array, but also give it a fixed size, which defeats the purpose of
the dynamic array, especially since the dynamic array also includes meta
data in the event to specify its size.

Since the size of the name is at most 16 bytes (defined by IFNAMSIZ),
it is not worth spending the effort to determine the size of the string.

Just use a fixed size array and copy into it. This will save 4 bytes that
are used for the meta data that saves the size and position of a dynamic
array, and even slightly speed up the event processing.

Link: https://lkml.kernel.org/r/20220704091436.3705edbf@rorschach.local.home

Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-15 13:35:59 -04:00

104 lines
2.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM fib
#if !defined(_TRACE_FIB_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_FIB_H
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <net/ip_fib.h>
#include <linux/tracepoint.h>
TRACE_EVENT(fib_table_lookup,
TP_PROTO(u32 tb_id, const struct flowi4 *flp,
const struct fib_nh_common *nhc, int err),
TP_ARGS(tb_id, flp, nhc, err),
TP_STRUCT__entry(
__field( u32, tb_id )
__field( int, err )
__field( int, oif )
__field( int, iif )
__field( u8, proto )
__field( __u8, tos )
__field( __u8, scope )
__field( __u8, flags )
__array( __u8, src, 4 )
__array( __u8, dst, 4 )
__array( __u8, gw4, 4 )
__array( __u8, gw6, 16 )
__field( u16, sport )
__field( u16, dport )
__array(char, name, IFNAMSIZ )
),
TP_fast_assign(
struct in6_addr in6_zero = {};
struct net_device *dev;
struct in6_addr *in6;
__be32 *p32;
__entry->tb_id = tb_id;
__entry->err = err;
__entry->oif = flp->flowi4_oif;
__entry->iif = flp->flowi4_iif;
__entry->tos = flp->flowi4_tos;
__entry->scope = flp->flowi4_scope;
__entry->flags = flp->flowi4_flags;
p32 = (__be32 *) __entry->src;
*p32 = flp->saddr;
p32 = (__be32 *) __entry->dst;
*p32 = flp->daddr;
__entry->proto = flp->flowi4_proto;
if (__entry->proto == IPPROTO_TCP ||
__entry->proto == IPPROTO_UDP) {
__entry->sport = ntohs(flp->fl4_sport);
__entry->dport = ntohs(flp->fl4_dport);
} else {
__entry->sport = 0;
__entry->dport = 0;
}
dev = nhc ? nhc->nhc_dev : NULL;
strlcpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ);
if (nhc) {
if (nhc->nhc_gw_family == AF_INET) {
p32 = (__be32 *) __entry->gw4;
*p32 = nhc->nhc_gw.ipv4;
in6 = (struct in6_addr *)__entry->gw6;
*in6 = in6_zero;
} else if (nhc->nhc_gw_family == AF_INET6) {
p32 = (__be32 *) __entry->gw4;
*p32 = 0;
in6 = (struct in6_addr *)__entry->gw6;
*in6 = nhc->nhc_gw.ipv6;
}
} else {
p32 = (__be32 *) __entry->gw4;
*p32 = 0;
in6 = (struct in6_addr *)__entry->gw6;
*in6 = in6_zero;
}
),
TP_printk("table %u oif %d iif %d proto %u %pI4/%u -> %pI4/%u tos %d scope %d flags %x ==> dev %s gw %pI4/%pI6c err %d",
__entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
__entry->src, __entry->sport, __entry->dst, __entry->dport,
__entry->tos, __entry->scope, __entry->flags,
__entry->name, __entry->gw4, __entry->gw6, __entry->err)
);
#endif /* _TRACE_FIB_H */
/* This part must be outside protection */
#include <trace/define_trace.h>