Commit bcc00987 authored by Alexis Lothoré (eBPF Foundation)'s avatar Alexis Lothoré (eBPF Foundation) Committed by Alexei Starovoitov
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selftests/bpf: add network helpers to generate udp checksums 



network_helpers.c provides some helpers to generate ip checksums or ip
pseudo-header checksums, but not for upper layers (eg: udp checksums)

Add helpers for udp checksum to allow manually building udp packets.

Signed-off-by: default avatarAlexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Link: https://lore.kernel.org/r/20241120-flow_dissector-v3-12-45b46494f937@bootlin.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent a2f482c3

tools/testing/selftests/bpf/network_helpers.h

+42 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ typedef __u16 __sum16; 
#include <linux/sockios.h>

#include <linux/err.h>

#include <netinet/tcp.h>

#include <netinet/udp.h>

#include <bpf/bpf_endian.h>

#include <net/if.h>
@@ -193,6 +194,47 @@ static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 
	return csum_fold((__u32)s);

}



/**

 * build_udp_v4_csum - compute UDP checksum for UDP over IPv4

 *

 * Compute the checksum to embed in UDP header, composed of the sum of IP

 * pseudo-header checksum, UDP header checksum and UDP data checksum

 * @iph IP header

 * @udph UDP header, which must be immediately followed by UDP data

 *

 * Returns the total checksum

 */



static inline __sum16 build_udp_v4_csum(const struct iphdr *iph,

					const struct udphdr *udph)

{

	unsigned long sum;



	sum = csum_partial(udph, ntohs(udph->len), 0);

	return csum_tcpudp_magic(iph->saddr, iph->daddr, ntohs(udph->len),

				 IPPROTO_UDP, sum);

}



/**

 * build_udp_v6_csum - compute UDP checksum for UDP over IPv6

 *

 * Compute the checksum to embed in UDP header, composed of the sum of IPv6

 * pseudo-header checksum, UDP header checksum and UDP data checksum

 * @ip6h IPv6 header

 * @udph UDP header, which must be immediately followed by UDP data

 *

 * Returns the total checksum

 */

static inline __sum16 build_udp_v6_csum(const struct ipv6hdr *ip6h,

					const struct udphdr *udph)

{

	unsigned long sum;



	sum = csum_partial(udph, ntohs(udph->len), 0);

	return csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ntohs(udph->len),

			       IPPROTO_UDP, sum);

}



struct tmonitor_ctx;



#ifdef TRAFFIC_MONITOR