@@ -130,21 +130,21 @@ ipstats_stat_show_attrs_free(struct ipstats_stat_show_attrs *attrs)
free(attrs->tbs[i]);
}
-#define IPSTATS_RTA_PAYLOAD(TYPE, AT) \
- ({ \
+#define IPSTATS_RTA_PAYLOAD(VAR, AT) \
+ do { \
const struct rtattr *__at = (AT); \
- TYPE *__ret = NULL; \
+ size_t __at_sz = __at->rta_len - RTA_LENGTH(0); \
+ size_t __var_sz = sizeof(VAR); \
+ typeof(VAR) *__dest = &VAR; \
\
- if (__at != NULL && \
- __at->rta_len - RTA_LENGTH(0) >= sizeof(TYPE)) \
- __ret = RTA_DATA(__at); \
- __ret; \
- })
+ memset(__dest, 0, __var_sz); \
+ memcpy(__dest, RTA_DATA(__at), MIN(__at_sz, __var_sz)); \
+ } while (0)
static int ipstats_show_64(struct ipstats_stat_show_attrs *attrs,
unsigned int group, unsigned int subgroup)
{
- struct rtnl_link_stats64 *stats;
+ struct rtnl_link_stats64 stats;
const struct rtattr *at;
int err;
@@ -152,14 +152,10 @@ static int ipstats_show_64(struct ipstats_stat_show_attrs *attrs,
if (at == NULL)
return err;
- stats = IPSTATS_RTA_PAYLOAD(struct rtnl_link_stats64, at);
- if (stats == NULL) {
- fprintf(stderr, "Error: attribute payload too short");
- return -EINVAL;
- }
+ IPSTATS_RTA_PAYLOAD(stats, at);
open_json_object("stats64");
- print_stats64(stdout, stats, NULL, NULL);
+ print_stats64(stdout, &stats, NULL, NULL);
close_json_object();
return 0;
}
@@ -228,15 +224,10 @@ static void print_hw_stats64(FILE *fp, struct rtnl_hw_stats64 *s)
static int ipstats_show_hw64(const struct rtattr *at)
{
- struct rtnl_hw_stats64 *stats;
+ struct rtnl_hw_stats64 stats;
- stats = IPSTATS_RTA_PAYLOAD(struct rtnl_hw_stats64, at);
- if (stats == NULL) {
- fprintf(stderr, "Error: attribute payload too short");
- return -EINVAL;
- }
-
- print_hw_stats64(stdout, stats);
+ IPSTATS_RTA_PAYLOAD(stats, at);
+ print_hw_stats64(stdout, &stats);
return 0;
}
In Linux kernel commit 794c24e9921f ("net-core: rx_otherhost_dropped to core_stats"), struct rtnl_link_stats64 got a new member. This change got to iproute2 through commit bba95837524d ("Update kernel headers"). "ip stats" makes the assumption that the payload of attributes that carry structures is at least as long as the size of the given structure as iproute2 knows it. But that will not hold when a newer iproute2 is used against an older kernel: since such kernel misses some fields on the tail end of the structure, "ip stats" bails out: # ip stats show group link 1: lo: group link Error: attribute payload too shortDump terminated Instead, be tolerant of responses that are both longer and shorter than what is expected. Instead of forming a pointer directly into the payload, allocate the stats structure on the stack, zero it, and then copy over the portion from the response. Reported-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> --- ip/ipstats.c | 37 ++++++++++++++----------------------- 1 file changed, 14 insertions(+), 23 deletions(-)