@@ -13,6 +13,7 @@ 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>
@@ -192,6 +193,47 @@ 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
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: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com> --- Changes in v3: - reuse pseudo-header checksum helper in the new helpers - reduce parameters list (eg: it does not make sense to passe the l4 protocol in a udp-specific helper) Changes in v2: - new patch --- tools/testing/selftests/bpf/network_helpers.h | 42 +++++++++++++++++++++++++++ 1 file changed, 42 insertions(+)