[RFC net-next PATCH 1/5] samples/bpf: xdp_tx_iptunnel make use of map_data[]

Jesper Dangaard Brouer
2017-05-18T15:41:36Z

There is no reason to use a compile time constant MAX_IPTNL_ENTRIES
shared between the _user.c and _kern.c, when map_data[].def.max_entries
can tell us dynamically what the max_entries were of the ELF map that
the bpf loaded created.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
samples/bpf/xdp_tx_iptunnel_common.h | 2 --
samples/bpf/xdp_tx_iptunnel_kern.c | 2 +-
samples/bpf/xdp_tx_iptunnel_user.c | 14 +++++++++-----
3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/samples/bpf/xdp_tx_iptunnel_common.h b/samples/bpf/xdp_tx_iptunnel_common.h
index dd12cc35110f..b065699cacb5 100644
--- a/samples/bpf/xdp_tx_iptunnel_common.h
+++ b/samples/bpf/xdp_tx_iptunnel_common.h
@@ -9,8 +9,6 @@

#include <linux/types.h>

-#define MAX_IPTNL_ENTRIES 256U
-
struct vip {
union {
__u32 v6[4];
diff --git a/samples/bpf/xdp_tx_iptunnel_kern.c b/samples/bpf/xdp_tx_iptunnel_kern.c
index 0f4f6e8c8611..b19489eb3c22 100644
--- a/samples/bpf/xdp_tx_iptunnel_kern.c
+++ b/samples/bpf/xdp_tx_iptunnel_kern.c
@@ -30,7 +30,7 @@ struct bpf_map_def SEC("maps") vip2tnl = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(struct vip),
.value_size = sizeof(struct iptnl_info),
- .max_entries = MAX_IPTNL_ENTRIES,
+ .max_entries = 256,
};

static __always_inline void count_tx(u32 protocol)
diff --git a/samples/bpf/xdp_tx_iptunnel_user.c b/samples/bpf/xdp_tx_iptunnel_user.c
index 92b8bde9337c..0500a5cc75c4 100644
--- a/samples/bpf/xdp_tx_iptunnel_user.c
+++ b/samples/bpf/xdp_tx_iptunnel_user.c
@@ -123,11 +123,6 @@ static int parse_ports(const char *port_str, int *min_port, int *max_port)
return 1;
}

- if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
- fprintf(stderr, "Port range (%s) is larger than %u\n",
- port_str, MAX_IPTNL_ENTRIES);
- return 1;
- }
*min_port = tmp_min_port;
*max_port = tmp_max_port;

@@ -142,6 +137,7 @@ int main(int argc, char **argv)
int min_port = 0, max_port = 0;
struct iptnl_info tnl = {};
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+ unsigned int entries, max_entries;
struct vip vip = {};
char filename[256];
int opt;
@@ -238,6 +234,14 @@ int main(int argc, char **argv)
return 1;
}

+ entries = max_port - min_port + 1;
+ max_entries = map_data[1].def.max_entries;
+ if (entries > max_entries) {
+ fprintf(stderr, "Req port entries (%u) is larger than max %u\n",
+ entries, max_entries);
+ return 1;
+ }
+
signal(SIGINT, int_exit);

while (min_port <= max_port) {