* [PATCH] samples: bpf: add max_pckt_size option at xdp_adjust_tail
@ 2019-08-26 9:57 Daniel T. Lee
2019-08-26 15:54 ` Maciej Fijalkowski
0 siblings, 1 reply; 3+ messages in thread
From: Daniel T. Lee @ 2019-08-26 9:57 UTC (permalink / raw)
To: Daniel Borkmann, Alexei Starovoitov; +Cc: netdev
Currently, at xdp_adjust_tail_kern.c, MAX_PCKT_SIZE is limited
to 600. To make this size flexible, a new map 'pcktsz' is added.
By updating new packet size to this map from the userland,
xdp_adjust_tail_kern.o will use this value as a new max_pckt_size.
If no '-P <MAX_PCKT_SIZE>' option is used, the size of maximum packet
will be 600 as a default.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
---
samples/bpf/xdp_adjust_tail_kern.c | 23 +++++++++++++++++++----
samples/bpf/xdp_adjust_tail_user.c | 21 +++++++++++++++++++--
2 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
index 411fdb21f8bc..4d53af370b68 100644
--- a/samples/bpf/xdp_adjust_tail_kern.c
+++ b/samples/bpf/xdp_adjust_tail_kern.c
@@ -25,6 +25,13 @@
#define ICMP_TOOBIG_SIZE 98
#define ICMP_TOOBIG_PAYLOAD_SIZE 92
+struct bpf_map_def SEC("maps") pcktsz = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(__u32),
+ .max_entries = 1,
+};
+
struct bpf_map_def SEC("maps") icmpcnt = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
@@ -64,7 +71,8 @@ static __always_inline void ipv4_csum(void *data_start, int data_size,
*csum = csum_fold_helper(*csum);
}
-static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
+static __always_inline int send_icmp4_too_big(struct xdp_md *xdp,
+ __u32 max_pckt_size)
{
int headroom = (int)sizeof(struct iphdr) + (int)sizeof(struct icmphdr);
@@ -92,7 +100,7 @@ static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
orig_iph = data + off;
icmp_hdr->type = ICMP_DEST_UNREACH;
icmp_hdr->code = ICMP_FRAG_NEEDED;
- icmp_hdr->un.frag.mtu = htons(MAX_PCKT_SIZE-sizeof(struct ethhdr));
+ icmp_hdr->un.frag.mtu = htons(max_pckt_size - sizeof(struct ethhdr));
icmp_hdr->checksum = 0;
ipv4_csum(icmp_hdr, ICMP_TOOBIG_PAYLOAD_SIZE, &csum);
icmp_hdr->checksum = csum;
@@ -118,14 +126,21 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp)
{
void *data_end = (void *)(long)xdp->data_end;
void *data = (void *)(long)xdp->data;
+ __u32 max_pckt_size = MAX_PCKT_SIZE;
+ __u32 *pckt_sz;
+ __u32 key = 0;
int pckt_size = data_end - data;
int offset;
- if (pckt_size > MAX_PCKT_SIZE) {
+ pckt_sz = bpf_map_lookup_elem(&pcktsz, &key);
+ if (pckt_sz && *pckt_sz)
+ max_pckt_size = *pckt_sz;
+
+ if (pckt_size > max_pckt_size) {
offset = pckt_size - ICMP_TOOBIG_SIZE;
if (bpf_xdp_adjust_tail(xdp, 0 - offset))
return XDP_PASS;
- return send_icmp4_too_big(xdp);
+ return send_icmp4_too_big(xdp, max_pckt_size);
}
return XDP_PASS;
}
diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
index a3596b617c4c..dd3befa5e1fe 100644
--- a/samples/bpf/xdp_adjust_tail_user.c
+++ b/samples/bpf/xdp_adjust_tail_user.c
@@ -72,6 +72,7 @@ static void usage(const char *cmd)
printf("Usage: %s [...]\n", cmd);
printf(" -i <ifname|ifindex> Interface\n");
printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
+ printf(" -P <MAX_PCKT_SIZE> Default: 600\n");
printf(" -S use skb-mode\n");
printf(" -N enforce native mode\n");
printf(" -F force loading prog\n");
@@ -85,9 +86,11 @@ int main(int argc, char **argv)
.prog_type = BPF_PROG_TYPE_XDP,
};
unsigned char opt_flags[256] = {};
- const char *optstr = "i:T:SNFh";
+ const char *optstr = "i:T:P:SNFh";
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
+ __u32 max_pckt_size = 0;
+ __u32 key = 0;
unsigned int kill_after_s = 0;
int i, prog_fd, map_fd, opt;
struct bpf_object *obj;
@@ -110,6 +113,9 @@ int main(int argc, char **argv)
case 'T':
kill_after_s = atoi(optarg);
break;
+ case 'P':
+ max_pckt_size = atoi(optarg);
+ break;
case 'S':
xdp_flags |= XDP_FLAGS_SKB_MODE;
break;
@@ -150,9 +156,20 @@ int main(int argc, char **argv)
if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
return 1;
+ /* update pcktsz map */
map = bpf_map__next(NULL, obj);
if (!map) {
- printf("finding a map in obj file failed\n");
+ printf("finding a pcktsz map in obj file failed\n");
+ return 1;
+ }
+ map_fd = bpf_map__fd(map);
+ if (max_pckt_size)
+ bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
+
+ /* fetch icmpcnt map */
+ map = bpf_map__next(map, obj);
+ if (!map) {
+ printf("finding a icmpcnt map in obj file failed\n");
return 1;
}
map_fd = bpf_map__fd(map);
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] samples: bpf: add max_pckt_size option at xdp_adjust_tail
2019-08-26 9:57 [PATCH] samples: bpf: add max_pckt_size option at xdp_adjust_tail Daniel T. Lee
@ 2019-08-26 15:54 ` Maciej Fijalkowski
2019-08-26 16:26 ` Daniel T. Lee
0 siblings, 1 reply; 3+ messages in thread
From: Maciej Fijalkowski @ 2019-08-26 15:54 UTC (permalink / raw)
To: Daniel T. Lee; +Cc: Daniel Borkmann, Alexei Starovoitov, netdev
On Mon, 26 Aug 2019 18:57:22 +0900
"Daniel T. Lee" <danieltimlee@gmail.com> wrote:
> Currently, at xdp_adjust_tail_kern.c, MAX_PCKT_SIZE is limited
> to 600. To make this size flexible, a new map 'pcktsz' is added.
>
> By updating new packet size to this map from the userland,
> xdp_adjust_tail_kern.o will use this value as a new max_pckt_size.
>
> If no '-P <MAX_PCKT_SIZE>' option is used, the size of maximum packet
> will be 600 as a default.
>
> Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
> ---
> samples/bpf/xdp_adjust_tail_kern.c | 23 +++++++++++++++++++----
> samples/bpf/xdp_adjust_tail_user.c | 21 +++++++++++++++++++--
> 2 files changed, 38 insertions(+), 6 deletions(-)
>
> diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
> index 411fdb21f8bc..4d53af370b68 100644
> --- a/samples/bpf/xdp_adjust_tail_kern.c
> +++ b/samples/bpf/xdp_adjust_tail_kern.c
> @@ -25,6 +25,13 @@
> #define ICMP_TOOBIG_SIZE 98
> #define ICMP_TOOBIG_PAYLOAD_SIZE 92
>
> +struct bpf_map_def SEC("maps") pcktsz = {
> + .type = BPF_MAP_TYPE_ARRAY,
> + .key_size = sizeof(__u32),
> + .value_size = sizeof(__u32),
> + .max_entries = 1,
> +};
> +
> struct bpf_map_def SEC("maps") icmpcnt = {
> .type = BPF_MAP_TYPE_ARRAY,
> .key_size = sizeof(__u32),
> @@ -64,7 +71,8 @@ static __always_inline void ipv4_csum(void *data_start, int data_size,
> *csum = csum_fold_helper(*csum);
> }
>
> -static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
> +static __always_inline int send_icmp4_too_big(struct xdp_md *xdp,
> + __u32 max_pckt_size)
> {
> int headroom = (int)sizeof(struct iphdr) + (int)sizeof(struct icmphdr);
>
> @@ -92,7 +100,7 @@ static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
> orig_iph = data + off;
> icmp_hdr->type = ICMP_DEST_UNREACH;
> icmp_hdr->code = ICMP_FRAG_NEEDED;
> - icmp_hdr->un.frag.mtu = htons(MAX_PCKT_SIZE-sizeof(struct ethhdr));
> + icmp_hdr->un.frag.mtu = htons(max_pckt_size - sizeof(struct ethhdr));
> icmp_hdr->checksum = 0;
> ipv4_csum(icmp_hdr, ICMP_TOOBIG_PAYLOAD_SIZE, &csum);
> icmp_hdr->checksum = csum;
> @@ -118,14 +126,21 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp)
> {
> void *data_end = (void *)(long)xdp->data_end;
> void *data = (void *)(long)xdp->data;
> + __u32 max_pckt_size = MAX_PCKT_SIZE;
> + __u32 *pckt_sz;
> + __u32 key = 0;
> int pckt_size = data_end - data;
> int offset;
>
> - if (pckt_size > MAX_PCKT_SIZE) {
> + pckt_sz = bpf_map_lookup_elem(&pcktsz, &key);
> + if (pckt_sz && *pckt_sz)
> + max_pckt_size = *pckt_sz;
> +
> + if (pckt_size > max_pckt_size) {
> offset = pckt_size - ICMP_TOOBIG_SIZE;
> if (bpf_xdp_adjust_tail(xdp, 0 - offset))
> return XDP_PASS;
> - return send_icmp4_too_big(xdp);
> + return send_icmp4_too_big(xdp, max_pckt_size);
> }
> return XDP_PASS;
> }
> diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
> index a3596b617c4c..dd3befa5e1fe 100644
> --- a/samples/bpf/xdp_adjust_tail_user.c
> +++ b/samples/bpf/xdp_adjust_tail_user.c
> @@ -72,6 +72,7 @@ static void usage(const char *cmd)
> printf("Usage: %s [...]\n", cmd);
> printf(" -i <ifname|ifindex> Interface\n");
> printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
> + printf(" -P <MAX_PCKT_SIZE> Default: 600\n");
> printf(" -S use skb-mode\n");
> printf(" -N enforce native mode\n");
> printf(" -F force loading prog\n");
> @@ -85,9 +86,11 @@ int main(int argc, char **argv)
> .prog_type = BPF_PROG_TYPE_XDP,
> };
> unsigned char opt_flags[256] = {};
> - const char *optstr = "i:T:SNFh";
> + const char *optstr = "i:T:P:SNFh";
> struct bpf_prog_info info = {};
> __u32 info_len = sizeof(info);
> + __u32 max_pckt_size = 0;
> + __u32 key = 0;
> unsigned int kill_after_s = 0;
> int i, prog_fd, map_fd, opt;
> struct bpf_object *obj;
> @@ -110,6 +113,9 @@ int main(int argc, char **argv)
> case 'T':
> kill_after_s = atoi(optarg);
> break;
> + case 'P':
> + max_pckt_size = atoi(optarg);
> + break;
> case 'S':
> xdp_flags |= XDP_FLAGS_SKB_MODE;
> break;
> @@ -150,9 +156,20 @@ int main(int argc, char **argv)
> if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
> return 1;
>
> + /* update pcktsz map */
> map = bpf_map__next(NULL, obj);
> if (!map) {
> - printf("finding a map in obj file failed\n");
> + printf("finding a pcktsz map in obj file failed\n");
> + return 1;
> + }
> + map_fd = bpf_map__fd(map);
Consider using bpf_object__find_map_fd_by_name() here.
> + if (max_pckt_size)
> + bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
> +
> + /* fetch icmpcnt map */
> + map = bpf_map__next(map, obj);
> + if (!map) {
> + printf("finding a icmpcnt map in obj file failed\n");
> return 1;
> }
> map_fd = bpf_map__fd(map);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] samples: bpf: add max_pckt_size option at xdp_adjust_tail
2019-08-26 15:54 ` Maciej Fijalkowski
@ 2019-08-26 16:26 ` Daniel T. Lee
0 siblings, 0 replies; 3+ messages in thread
From: Daniel T. Lee @ 2019-08-26 16:26 UTC (permalink / raw)
To: Maciej Fijalkowski; +Cc: Daniel Borkmann, Alexei Starovoitov, netdev
On Tue, Aug 27, 2019 at 12:54 AM Maciej Fijalkowski
<maciejromanfijalkowski@gmail.com> wrote:
>
> On Mon, 26 Aug 2019 18:57:22 +0900
> "Daniel T. Lee" <danieltimlee@gmail.com> wrote:
>
> > Currently, at xdp_adjust_tail_kern.c, MAX_PCKT_SIZE is limited
> > to 600. To make this size flexible, a new map 'pcktsz' is added.
> >
> > By updating new packet size to this map from the userland,
> > xdp_adjust_tail_kern.o will use this value as a new max_pckt_size.
> >
> > If no '-P <MAX_PCKT_SIZE>' option is used, the size of maximum packet
> > will be 600 as a default.
> >
> > Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
> > ---
> > samples/bpf/xdp_adjust_tail_kern.c | 23 +++++++++++++++++++----
> > samples/bpf/xdp_adjust_tail_user.c | 21 +++++++++++++++++++--
> > 2 files changed, 38 insertions(+), 6 deletions(-)
> >
> > diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
> > index 411fdb21f8bc..4d53af370b68 100644
> > --- a/samples/bpf/xdp_adjust_tail_kern.c
> > +++ b/samples/bpf/xdp_adjust_tail_kern.c
> > @@ -25,6 +25,13 @@
> > #define ICMP_TOOBIG_SIZE 98
> > #define ICMP_TOOBIG_PAYLOAD_SIZE 92
> >
> > +struct bpf_map_def SEC("maps") pcktsz = {
> > + .type = BPF_MAP_TYPE_ARRAY,
> > + .key_size = sizeof(__u32),
> > + .value_size = sizeof(__u32),
> > + .max_entries = 1,
> > +};
> > +
> > struct bpf_map_def SEC("maps") icmpcnt = {
> > .type = BPF_MAP_TYPE_ARRAY,
> > .key_size = sizeof(__u32),
> > @@ -64,7 +71,8 @@ static __always_inline void ipv4_csum(void *data_start, int data_size,
> > *csum = csum_fold_helper(*csum);
> > }
> >
> > -static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
> > +static __always_inline int send_icmp4_too_big(struct xdp_md *xdp,
> > + __u32 max_pckt_size)
> > {
> > int headroom = (int)sizeof(struct iphdr) + (int)sizeof(struct icmphdr);
> >
> > @@ -92,7 +100,7 @@ static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
> > orig_iph = data + off;
> > icmp_hdr->type = ICMP_DEST_UNREACH;
> > icmp_hdr->code = ICMP_FRAG_NEEDED;
> > - icmp_hdr->un.frag.mtu = htons(MAX_PCKT_SIZE-sizeof(struct ethhdr));
> > + icmp_hdr->un.frag.mtu = htons(max_pckt_size - sizeof(struct ethhdr));
> > icmp_hdr->checksum = 0;
> > ipv4_csum(icmp_hdr, ICMP_TOOBIG_PAYLOAD_SIZE, &csum);
> > icmp_hdr->checksum = csum;
> > @@ -118,14 +126,21 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp)
> > {
> > void *data_end = (void *)(long)xdp->data_end;
> > void *data = (void *)(long)xdp->data;
> > + __u32 max_pckt_size = MAX_PCKT_SIZE;
> > + __u32 *pckt_sz;
> > + __u32 key = 0;
> > int pckt_size = data_end - data;
> > int offset;
> >
> > - if (pckt_size > MAX_PCKT_SIZE) {
> > + pckt_sz = bpf_map_lookup_elem(&pcktsz, &key);
> > + if (pckt_sz && *pckt_sz)
> > + max_pckt_size = *pckt_sz;
> > +
> > + if (pckt_size > max_pckt_size) {
> > offset = pckt_size - ICMP_TOOBIG_SIZE;
> > if (bpf_xdp_adjust_tail(xdp, 0 - offset))
> > return XDP_PASS;
> > - return send_icmp4_too_big(xdp);
> > + return send_icmp4_too_big(xdp, max_pckt_size);
> > }
> > return XDP_PASS;
> > }
> > diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
> > index a3596b617c4c..dd3befa5e1fe 100644
> > --- a/samples/bpf/xdp_adjust_tail_user.c
> > +++ b/samples/bpf/xdp_adjust_tail_user.c
> > @@ -72,6 +72,7 @@ static void usage(const char *cmd)
> > printf("Usage: %s [...]\n", cmd);
> > printf(" -i <ifname|ifindex> Interface\n");
> > printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
> > + printf(" -P <MAX_PCKT_SIZE> Default: 600\n");
> > printf(" -S use skb-mode\n");
> > printf(" -N enforce native mode\n");
> > printf(" -F force loading prog\n");
> > @@ -85,9 +86,11 @@ int main(int argc, char **argv)
> > .prog_type = BPF_PROG_TYPE_XDP,
> > };
> > unsigned char opt_flags[256] = {};
> > - const char *optstr = "i:T:SNFh";
> > + const char *optstr = "i:T:P:SNFh";
> > struct bpf_prog_info info = {};
> > __u32 info_len = sizeof(info);
> > + __u32 max_pckt_size = 0;
> > + __u32 key = 0;
> > unsigned int kill_after_s = 0;
> > int i, prog_fd, map_fd, opt;
> > struct bpf_object *obj;
> > @@ -110,6 +113,9 @@ int main(int argc, char **argv)
> > case 'T':
> > kill_after_s = atoi(optarg);
> > break;
> > + case 'P':
> > + max_pckt_size = atoi(optarg);
> > + break;
> > case 'S':
> > xdp_flags |= XDP_FLAGS_SKB_MODE;
> > break;
> > @@ -150,9 +156,20 @@ int main(int argc, char **argv)
> > if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
> > return 1;
> >
> > + /* update pcktsz map */
> > map = bpf_map__next(NULL, obj);
> > if (!map) {
> > - printf("finding a map in obj file failed\n");
> > + printf("finding a pcktsz map in obj file failed\n");
> > + return 1;
> > + }
> > + map_fd = bpf_map__fd(map);
>
> Consider using bpf_object__find_map_fd_by_name() here.
>
> > + if (max_pckt_size)
> > + bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
> > +
> > + /* fetch icmpcnt map */
> > + map = bpf_map__next(map, obj);
> > + if (!map) {
> > + printf("finding a icmpcnt map in obj file failed\n");
> > return 1;
> > }
> > map_fd = bpf_map__fd(map);
>
Thanks for the review!
I'll update it right away.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-08-26 9:57 [PATCH] samples: bpf: add max_pckt_size option at xdp_adjust_tail Daniel T. Lee
2019-08-26 15:54 ` Maciej Fijalkowski
2019-08-26 16:26 ` Daniel T. Lee
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