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* [bpf-next,v4] samples: bpf: add max_pckt_size option at xdp_adjust_tail
@ 2019-09-15 12:47 Daniel T. Lee
  2019-09-16 16:07 ` Yonghong Song
  0 siblings, 1 reply; 3+ messages in thread
From: Daniel T. Lee @ 2019-09-15 12:47 UTC (permalink / raw)
  To: Daniel Borkmann, Alexei Starovoitov; +Cc: netdev, bpf

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>

---
Changes in v4:
    - make pckt_size no less than ICMP_TOOBIG_SIZE
    - Fix code style
Changes in v2:
    - Change the helper to fetch map from 'bpf_map__next' to 
    'bpf_object__find_map_fd_by_name'.

 samples/bpf/xdp_adjust_tail_kern.c | 23 +++++++++++++++++++----
 samples/bpf/xdp_adjust_tail_user.c | 28 ++++++++++++++++++++++------
 2 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
index 411fdb21f8bc..8869bbb160d2 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;
 	int pckt_size = data_end - data;
+	__u32 *pckt_sz;
+	__u32 key = 0;
 	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(max_pckt_size, ICMP_TOOBIG_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..99e965c68054 100644
--- a/samples/bpf/xdp_adjust_tail_user.c
+++ b/samples/bpf/xdp_adjust_tail_user.c
@@ -23,6 +23,7 @@
 #include "libbpf.h"
 
 #define STATS_INTERVAL_S 2U
+#define MAX_PCKT_SIZE 600
 
 static int ifindex = -1;
 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
@@ -72,6 +73,7 @@ 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: %u\n", MAX_PCKT_SIZE);
 	printf("    -S use skb-mode\n");
 	printf("    -N enforce native mode\n");
 	printf("    -F force loading prog\n");
@@ -85,13 +87,14 @@ 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;
-	struct bpf_map *map;
 	char filename[256];
 	int err;
 
@@ -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;
@@ -150,12 +156,22 @@ int main(int argc, char **argv)
 	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
 		return 1;
 
-	map = bpf_map__next(NULL, obj);
-	if (!map) {
-		printf("finding a map in obj file failed\n");
+	/* update pcktsz map */
+	if (max_pckt_size) {
+		map_fd = bpf_object__find_map_fd_by_name(obj, "pcktsz");
+		if (map_fd < 0) {
+			printf("finding a pcktsz map in obj file failed\n");
+			return 1;
+		}
+		bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
+	}
+
+	/* fetch icmpcnt map */
+	map_fd = bpf_object__find_map_fd_by_name(obj, "icmpcnt");
+	if (map_fd < 0) {
+		printf("finding a icmpcnt map in obj file failed\n");
 		return 1;
 	}
-	map_fd = bpf_map__fd(map);
 
 	if (!prog_fd) {
 		printf("load_bpf_file: %s\n", strerror(errno));
-- 
2.20.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [bpf-next,v4] samples: bpf: add max_pckt_size option at xdp_adjust_tail
  2019-09-15 12:47 [bpf-next,v4] samples: bpf: add max_pckt_size option at xdp_adjust_tail Daniel T. Lee
@ 2019-09-16 16:07 ` Yonghong Song
  2019-09-16 16:55   ` Daniel T. Lee
  0 siblings, 1 reply; 3+ messages in thread
From: Yonghong Song @ 2019-09-16 16:07 UTC (permalink / raw)
  To: Daniel T. Lee, Daniel Borkmann, Alexei Starovoitov; +Cc: netdev, bpf



On 9/15/19 1:47 PM, Daniel T. Lee 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>
> 
> ---
> Changes in v4:
>      - make pckt_size no less than ICMP_TOOBIG_SIZE
>      - Fix code style
> Changes in v2:
>      - Change the helper to fetch map from 'bpf_map__next' to
>      'bpf_object__find_map_fd_by_name'.
> 
>   samples/bpf/xdp_adjust_tail_kern.c | 23 +++++++++++++++++++----
>   samples/bpf/xdp_adjust_tail_user.c | 28 ++++++++++++++++++++++------
>   2 files changed, 41 insertions(+), 10 deletions(-)

LGTM except a minor comments below.
Acked-by: Yonghong Song <yhs@fb.com>

bpf-next is closed. Please resubmit the patch once it is opened
in around 2 weeks.

> 
> diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
> index 411fdb21f8bc..8869bbb160d2 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;
>   	int pckt_size = data_end - data;
> +	__u32 *pckt_sz;
> +	__u32 key = 0;
>   	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(max_pckt_size, ICMP_TOOBIG_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..99e965c68054 100644
> --- a/samples/bpf/xdp_adjust_tail_user.c
> +++ b/samples/bpf/xdp_adjust_tail_user.c
> @@ -23,6 +23,7 @@
>   #include "libbpf.h"
>   
>   #define STATS_INTERVAL_S 2U
> +#define MAX_PCKT_SIZE 600
>   
>   static int ifindex = -1;
>   static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
> @@ -72,6 +73,7 @@ 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: %u\n", MAX_PCKT_SIZE);
>   	printf("    -S use skb-mode\n");
>   	printf("    -N enforce native mode\n");
>   	printf("    -F force loading prog\n");
> @@ -85,13 +87,14 @@ 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;
> -	struct bpf_map *map;
>   	char filename[256];
>   	int err;
>   
> @@ -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;
> @@ -150,12 +156,22 @@ int main(int argc, char **argv)
>   	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
>   		return 1;
>   
> -	map = bpf_map__next(NULL, obj);
> -	if (!map) {
> -		printf("finding a map in obj file failed\n");
> +	/* update pcktsz map */
> +	if (max_pckt_size) {
> +		map_fd = bpf_object__find_map_fd_by_name(obj, "pcktsz");
> +		if (map_fd < 0) {
> +			printf("finding a pcktsz map in obj file failed\n");
> +			return 1;
> +		}
> +		bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
> +	}
> +
> +	/* fetch icmpcnt map */
> +	map_fd = bpf_object__find_map_fd_by_name(obj, "icmpcnt");
> +	if (map_fd < 0) {
> +		printf("finding a icmpcnt map in obj file failed\n");
>   		return 1;
>   	}
> -	map_fd = bpf_map__fd(map);
>   
>   	if (!prog_fd) {
>   		printf("load_bpf_file: %s\n", strerror(errno));

Could you move the 'if (!prog_fd) ...' right after 'bpf_prog_load_xattr'
for readability reason?

Could you also change the condition 'if (!prog_fd)' to 'if (prog_fd < 
0)'? You need to mention this fix in your commit message as well.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [bpf-next,v4] samples: bpf: add max_pckt_size option at xdp_adjust_tail
  2019-09-16 16:07 ` Yonghong Song
@ 2019-09-16 16:55   ` Daniel T. Lee
  0 siblings, 0 replies; 3+ messages in thread
From: Daniel T. Lee @ 2019-09-16 16:55 UTC (permalink / raw)
  To: Yonghong Song; +Cc: Daniel Borkmann, Alexei Starovoitov, netdev, bpf

On Tue, Sep 17, 2019 at 1:07 AM Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 9/15/19 1:47 PM, Daniel T. Lee 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>
> >
> > ---
> > Changes in v4:
> >      - make pckt_size no less than ICMP_TOOBIG_SIZE
> >      - Fix code style
> > Changes in v2:
> >      - Change the helper to fetch map from 'bpf_map__next' to
> >      'bpf_object__find_map_fd_by_name'.
> >
> >   samples/bpf/xdp_adjust_tail_kern.c | 23 +++++++++++++++++++----
> >   samples/bpf/xdp_adjust_tail_user.c | 28 ++++++++++++++++++++++------
> >   2 files changed, 41 insertions(+), 10 deletions(-)
>
> LGTM except a minor comments below.
> Acked-by: Yonghong Song <yhs@fb.com>
>
> bpf-next is closed. Please resubmit the patch once it is opened
> in around 2 weeks.
>
> >
> > diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
> > index 411fdb21f8bc..8869bbb160d2 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;
> >       int pckt_size = data_end - data;
> > +     __u32 *pckt_sz;
> > +     __u32 key = 0;
> >       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(max_pckt_size, ICMP_TOOBIG_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..99e965c68054 100644
> > --- a/samples/bpf/xdp_adjust_tail_user.c
> > +++ b/samples/bpf/xdp_adjust_tail_user.c
> > @@ -23,6 +23,7 @@
> >   #include "libbpf.h"
> >
> >   #define STATS_INTERVAL_S 2U
> > +#define MAX_PCKT_SIZE 600
> >
> >   static int ifindex = -1;
> >   static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
> > @@ -72,6 +73,7 @@ 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: %u\n", MAX_PCKT_SIZE);
> >       printf("    -S use skb-mode\n");
> >       printf("    -N enforce native mode\n");
> >       printf("    -F force loading prog\n");
> > @@ -85,13 +87,14 @@ 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;
> > -     struct bpf_map *map;
> >       char filename[256];
> >       int err;
> >
> > @@ -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;
> > @@ -150,12 +156,22 @@ int main(int argc, char **argv)
> >       if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
> >               return 1;
> >
> > -     map = bpf_map__next(NULL, obj);
> > -     if (!map) {
> > -             printf("finding a map in obj file failed\n");
> > +     /* update pcktsz map */
> > +     if (max_pckt_size) {
> > +             map_fd = bpf_object__find_map_fd_by_name(obj, "pcktsz");
> > +             if (map_fd < 0) {
> > +                     printf("finding a pcktsz map in obj file failed\n");
> > +                     return 1;
> > +             }
> > +             bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
> > +     }
> > +
> > +     /* fetch icmpcnt map */
> > +     map_fd = bpf_object__find_map_fd_by_name(obj, "icmpcnt");
> > +     if (map_fd < 0) {
> > +             printf("finding a icmpcnt map in obj file failed\n");
> >               return 1;
> >       }
> > -     map_fd = bpf_map__fd(map);
> >
> >       if (!prog_fd) {
> >               printf("load_bpf_file: %s\n", strerror(errno));
>
> Could you move the 'if (!prog_fd) ...' right after 'bpf_prog_load_xattr'
> for readability reason?
>
> Could you also change the condition 'if (!prog_fd)' to 'if (prog_fd <
> 0)'? You need to mention this fix in your commit message as well.


Thanks for the review!

I'll resubmit the patch with this changes included when bpf-next opens.
And also the commit message as well.

Thanks,
Daniel

^ permalink raw reply	[flat|nested] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-15 12:47 [bpf-next,v4] samples: bpf: add max_pckt_size option at xdp_adjust_tail Daniel T. Lee
2019-09-16 16:07 ` Yonghong Song
2019-09-16 16:55   ` Daniel T. Lee

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