diff mbox series

[5/5] xfrm: Support crypto offload for outbound IPv4 UDP-encapsulated ESP packet

Message ID 20240713102416.3272997-6-steffen.klassert@secunet.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series [1/5] xfrm: support sending NAT keepalives in ESP in UDP states | expand

Checks

Context Check Description
netdev/series_format warning Pull request is its own cover letter; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 816 this patch: 816
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 3 maintainers not CCed: edumazet@google.com dsahern@kernel.org pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 821 this patch: 821
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 821 this patch: 821
netdev/checkpatch warning WARNING: line length of 92 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns WARNING: line length of 98 exceeds 80 columns WARNING: line length of 99 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-07-14--09-00 (tests: 696)

Commit Message

Steffen Klassert July 13, 2024, 10:24 a.m. UTC 
From: Mike Yu <yumike@google.com>

esp_xmit() is already able to handle UDP encapsulation through the call to
esp_output_head(). However, the ESP header and the outer IP header
are not correct and need to be corrected.

Test: Enabled both dir=in/out IPsec crypto offload, and verified IPv4
      UDP-encapsulated ESP packets on both wifi/cellular network
Signed-off-by: Mike Yu <yumike@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv4/esp4.c         |  8 +++++++-
 net/ipv4/esp4_offload.c | 17 ++++++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 3968d3f98e08..73981595f062 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -349,6 +349,7 @@  static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb,
 {
 	struct udphdr *uh;
 	unsigned int len;
+	struct xfrm_offload *xo = xfrm_offload(skb);
 
 	len = skb->len + esp->tailen - skb_transport_offset(skb);
 	if (len + sizeof(struct iphdr) > IP_MAX_MTU)
@@ -360,7 +361,12 @@  static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb,
 	uh->len = htons(len);
 	uh->check = 0;
 
-	*skb_mac_header(skb) = IPPROTO_UDP;
+	/* For IPv4 ESP with UDP encapsulation, if xo is not null, the skb is in the crypto offload
+	 * data path, which means that esp_output_udp_encap is called outside of the XFRM stack.
+	 * In this case, the mac header doesn't point to the IPv4 protocol field, so don't set it.
+	 */
+	if (!xo || encap_type != UDP_ENCAP_ESPINUDP)
+		*skb_mac_header(skb) = IPPROTO_UDP;
 
 	return (struct ip_esp_hdr *)(uh + 1);
 }
diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
index b3271957ad9a..a37d18858c72 100644
--- a/net/ipv4/esp4_offload.c
+++ b/net/ipv4/esp4_offload.c
@@ -264,6 +264,7 @@  static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_
 	struct esp_info esp;
 	bool hw_offload = true;
 	__u32 seq;
+	int encap_type = 0;
 
 	esp.inplace = true;
 
@@ -296,8 +297,10 @@  static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_
 
 	esp.esph = ip_esp_hdr(skb);
 
+	if (x->encap)
+		encap_type = x->encap->encap_type;
 
-	if (!hw_offload || !skb_is_gso(skb)) {
+	if (!hw_offload || !skb_is_gso(skb) || (hw_offload && encap_type == UDP_ENCAP_ESPINUDP)) {
 		esp.nfrags = esp_output_head(x, skb, &esp);
 		if (esp.nfrags < 0)
 			return esp.nfrags;
@@ -324,6 +327,18 @@  static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_
 
 	esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
 
+	if (hw_offload && encap_type == UDP_ENCAP_ESPINUDP) {
+		/* In the XFRM stack, the encapsulation protocol is set to iphdr->protocol by
+		 * setting *skb_mac_header(skb) (see esp_output_udp_encap()) where skb->mac_header
+		 * points to iphdr->protocol (see xfrm4_tunnel_encap_add()).
+		 * However, in esp_xmit(), skb->mac_header doesn't point to iphdr->protocol.
+		 * Therefore, the protocol field needs to be corrected.
+		 */
+		ip_hdr(skb)->protocol = IPPROTO_UDP;
+
+		esph->seq_no = htonl(seq);
+	}
+
 	ip_hdr(skb)->tot_len = htons(skb->len);
 	ip_send_check(ip_hdr(skb));