From 447bc4b1906f100e65c662528b7ae4e1dc2e9b80 Mon Sep 17 00:00:00 2001 From: Mike Yu Date: Fri, 12 Jul 2024 10:51:25 +0800 Subject: [PATCH] xfrm: Support crypto offload for outbound IPv4 UDP-encapsulated ESP packet 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 Signed-off-by: Steffen Klassert --- net/ipv4/esp4.c | 8 +++++++- net/ipv4/esp4_offload.c | 17 ++++++++++++++++- 2 files changed, 23 insertions(+), 2 deletions(-) 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));