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AF_XDP-interaction: Move BTF code to separate setup vs. using

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Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
This commit is contained in:
Jesper Dangaard Brouer
2021-11-11 15:56:22 +01:00
parent 8703e1a320
commit e3c2ded159
1 changed files with 84 additions and 67 deletions
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151
AF_XDP-interaction/af_xdp_user.c
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@@ -69,6 +69,81 @@ struct xsk_socket_info {
struct stats_record prev_stats;
};
/**
* BTF setup XDP-hints
* -------------------
* Setup the data structures for accessing the XDP-hints provided by
* kernel side BPF-prog via decoding BTF-info provided in BPF
* ELF-object file.
*/
/* This struct BTF mirrors kernel-side struct xdp_hints_rx_time */
struct xdp_hints_rx_time {
__u32 btf_type_id; /* cached xsk_btf__btf_type_id(xbi) */
struct xsk_btf_info *xbi;
struct xsk_btf_member rx_ktime;
} xdp_hints_rx_time = { 0 };
/* This struct BTF mirrors kernel-side struct xdp_hints_mark */
struct xdp_hints_mark {
__u32 btf_type_id; /* cached xsk_btf__btf_type_id(xbi) */
struct xsk_btf_info *xbi;
struct xsk_btf_member mark;
} xdp_hints_mark = { 0 };
struct xsk_btf_info *setup_btf_info(struct btf *btf,
const char *struct_name)
{
struct xsk_btf_info *xbi = NULL;
int err;
err = xsk_btf__init_xdp_hint(btf, struct_name, &xbi);
if (err) {
fprintf(stderr, "WARN(%d): Cannot BTF find struct:%s\n",
err, struct_name);
return NULL;
}
if (!xsk_btf__has_field("btf_id", xbi)) {
fprintf(stderr, "ERR: %s doesn't contain member btf_id\n",
struct_name);
xsk_btf__free_xdp_hint(xbi);
return NULL;
}
if (debug_meta)
printf("Setup BTF based XDP hints for struct: %s\n",
struct_name);
return xbi;
}
int init_btf_info_via_bpf_object(struct bpf_object *bpf_obj)
{
struct btf *btf = bpf_object__btf(bpf_obj);
struct xsk_btf_info *xbi;
xbi = setup_btf_info(btf, "xdp_hints_rx_time");
if (xbi) {
/* Lookup info on required member "rx_ktime" */
if (!xsk_btf__field_member("rx_ktime", xbi,
&xdp_hints_rx_time.rx_ktime))
return -EBADSLT;
xdp_hints_rx_time.btf_type_id = xsk_btf__btf_type_id(xbi);
xdp_hints_rx_time.xbi = xbi;
}
xbi = setup_btf_info(btf, "xdp_hints_mark");
if (xbi) {
if (!xsk_btf__field_member("mark", xbi, &xdp_hints_mark.mark))
return -EBADSLT;
xdp_hints_mark.btf_type_id = xsk_btf__btf_type_id(xbi);
xdp_hints_mark.xbi = xbi;
}
return 0;
}
#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
static uint64_t gettime(void)
{
@@ -322,72 +397,14 @@ static inline void csum_replace2(__sum16 *sum, __be16 old, __be16 new)
*sum = ~csum16_add(csum16_sub(~(*sum), old), new);
}
/* This struct BTF mirrors kernel-side struct xdp_hints_rx_time */
struct xdp_hints_rx_time {
__u32 btf_type_id; /* cached xsk_btf__btf_type_id(xbi) */
struct xsk_btf_info *xbi;
struct xsk_btf_member rx_ktime;
} xdp_hints_rx_time = { 0 };
/* This struct BTF mirrors kernel-side struct xdp_hints_mark */
struct xdp_hints_mark {
__u32 btf_type_id; /* cached xsk_btf__btf_type_id(xbi) */
struct xsk_btf_info *xbi;
struct xsk_btf_member mark;
} xdp_hints_mark = { 0 };
struct xsk_btf_info *setup_btf_info(struct btf *btf,
const char *struct_name)
{
struct xsk_btf_info *xbi = NULL;
int err;
err = xsk_btf__init_xdp_hint(btf, struct_name, &xbi);
if (err) {
fprintf(stderr, "WARN(%d): Cannot BTF find struct:%s\n",
err, struct_name);
return NULL;
}
if (!xsk_btf__has_field("btf_id", xbi)) {
fprintf(stderr, "ERR: %s doesn't contain member btf_id\n",
struct_name);
xsk_btf__free_xdp_hint(xbi);
return NULL;
}
if (debug_meta)
printf("Setup BTF based XDP hints for struct: %s\n",
struct_name);
return xbi;
}
int init_btf_info_via_bpf_object(struct bpf_object *bpf_obj)
{
struct btf *btf = bpf_object__btf(bpf_obj);
struct xsk_btf_info *xbi;
xbi = setup_btf_info(btf, "xdp_hints_rx_time");
if (xbi) {
/* Lookup info on required member "rx_ktime" */
if (!xsk_btf__field_member("rx_ktime", xbi,
&xdp_hints_rx_time.rx_ktime))
return -EBADSLT;
xdp_hints_rx_time.btf_type_id = xsk_btf__btf_type_id(xbi);
xdp_hints_rx_time.xbi = xbi;
}
xbi = setup_btf_info(btf, "xdp_hints_mark");
if (xbi) {
if (!xsk_btf__field_member("mark", xbi, &xdp_hints_mark.mark))
return -EBADSLT;
xdp_hints_mark.btf_type_id = xsk_btf__btf_type_id(xbi);
xdp_hints_mark.xbi = xbi;
}
return 0;
}
/**
* BTF accessing XDP-hints
* -----------------------
* Accessing the XDP-hints via BTF requires setup done earlier. As our target
* application have real-time requirements, it is preferred that the setup can
* happen outside the packet processing path. E.g. avoid doing the setup first
* time a packet with a new BTF-ID is seen.
*/
static void print_meta_info_mark(uint8_t *pkt, struct xdp_hints_mark *meta)
{
@@ -471,7 +488,7 @@ static void print_meta_info_via_btf( uint8_t *pkt)
}
if (btf_id == xdp_hints_rx_time.btf_type_id) {
print_meta_info_time_faster(pkt, &xdp_hints_rx_time);
print_meta_info_time(pkt, &xdp_hints_rx_time);
} else if (btf_id == xdp_hints_mark.btf_type_id) {
print_meta_info_mark(pkt, &xdp_hints_mark);