netdev - [PATCH v3 17/19] psp: provide decapsulation and receive helper for drivers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250702171326.3265825-18-daniel.zahka@gmail.com>
Date: Wed,  2 Jul 2025 10:13:22 -0700
From: Daniel Zahka <daniel.zahka@...il.com>
To: Donald Hunter <donald.hunter@...il.com>,
	Jakub Kicinski <kuba@...nel.org>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Jonathan Corbet <corbet@....net>,
	Andrew Lunn <andrew+netdev@...n.ch>
Cc: Saeed Mahameed <saeedm@...dia.com>,
	Leon Romanovsky <leon@...nel.org>,
	Tariq Toukan <tariqt@...dia.com>,
	Boris Pismenny <borisp@...dia.com>,
	Kuniyuki Iwashima <kuniyu@...gle.com>,
	Willem de Bruijn <willemb@...gle.com>,
	David Ahern <dsahern@...nel.org>,
	Neal Cardwell <ncardwell@...gle.com>,
	Patrisious Haddad <phaddad@...dia.com>,
	Raed Salem <raeds@...dia.com>,
	Jianbo Liu <jianbol@...dia.com>,
	Dragos Tatulea <dtatulea@...dia.com>,
	Rahul Rameshbabu <rrameshbabu@...dia.com>,
	Stanislav Fomichev <sdf@...ichev.me>,
	Toke Høiland-Jørgensen <toke@...hat.com>,
	Alexander Lobakin <aleksander.lobakin@...el.com>,
	Jacob Keller <jacob.e.keller@...el.com>,
	netdev@...r.kernel.org
Subject: [PATCH v3 17/19] psp: provide decapsulation and receive helper for drivers

From: Raed Salem <raeds@...dia.com>

Create psp_rcv(), which drivers can call to psp decapsulate and attach
a psp_skb_ext to an skb.

psp_rcv() only supports what the PSP architecture specification refers
to as "transport mode" packets, where the L3 header is IPv6. psp_rcv()
also assumes that a psp trailer is present and should be pulled from
the skb.

Signed-off-by: Raed Salem <raeds@...dia.com>
Signed-off-by: Rahul Rameshbabu <rrameshbabu@...dia.com>
Signed-off-by: Daniel Zahka <daniel.zahka@...il.com>
---

Notes:
    v3:
    - patch introduced

 include/net/psp/functions.h |  1 +
 net/psp/psp_main.c          | 49 +++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/include/net/psp/functions.h b/include/net/psp/functions.h
index afb4f5929eec..8ecc396bcfff 100644
--- a/include/net/psp/functions.h
+++ b/include/net/psp/functions.h
@@ -18,6 +18,7 @@ psp_dev_create(struct net_device *netdev, struct psp_dev_ops *psd_ops,
 void psp_dev_unregister(struct psp_dev *psd);
 bool psp_encapsulate(struct net *net, struct sk_buff *skb,
 		     __be32 spi, u8 ver, __be16 sport);
+int psp_rcv(struct sk_buff *skb, u16 dev_id, u8 generation);
 
 /* Kernel-facing API */
 void psp_assoc_put(struct psp_assoc *pas);
diff --git a/net/psp/psp_main.c b/net/psp/psp_main.c
index 8229a004ba6e..ec60e06cdf69 100644
--- a/net/psp/psp_main.c
+++ b/net/psp/psp_main.c
@@ -195,6 +195,55 @@ bool psp_encapsulate(struct net *net, struct sk_buff *skb,
 }
 EXPORT_SYMBOL(psp_encapsulate);
 
+/* Receive handler for PSP packets.
+ *
+ * Presently it accepts only already-authenticated packets and does not
+ * support optional fields, such as virtualization cookies.
+ */
+int psp_rcv(struct sk_buff *skb, u16 dev_id, u8 generation)
+{
+	const struct psphdr *psph;
+	int depth = 0, end_depth;
+	struct psp_skb_ext *pse;
+	struct ipv6hdr *ipv6h;
+	struct ethhdr *eth;
+	__be16 proto;
+	u32 spi;
+
+	eth = (struct ethhdr *)(skb->data);
+	proto = __vlan_get_protocol(skb, eth->h_proto, &depth);
+	if (proto != htons(ETH_P_IPV6))
+		return -EINVAL;
+
+	ipv6h = (struct ipv6hdr *)(skb->data + depth);
+	depth += sizeof(*ipv6h);
+	end_depth = depth + sizeof(struct udphdr) + sizeof(struct psphdr);
+
+	if (unlikely(end_depth > skb_headlen(skb)))
+		return -EINVAL;
+
+	pse = skb_ext_add(skb, SKB_EXT_PSP);
+	if (!pse)
+		return -EINVAL;
+
+	psph = (const struct psphdr *)(skb->data + depth + sizeof(struct udphdr));
+	pse->spi = psph->spi;
+	pse->dev_id = dev_id;
+	spi = ntohl(psph->spi);
+	pse->generation = generation;
+	pse->version = FIELD_GET(PSPHDR_VERFL_VERSION, psph->verfl);
+
+	ipv6h->nexthdr = psph->nexthdr;
+	ipv6h->payload_len =
+		htons(ntohs(ipv6h->payload_len) - PSP_ENCAP_HLEN - PSP_TRL_SIZE);
+
+	memmove(skb->data + PSP_ENCAP_HLEN, skb->data, depth);
+	skb_pull(skb, PSP_ENCAP_HLEN);
+
+	return 0;
+}
+EXPORT_SYMBOL(psp_rcv);
+
 static int __init psp_init(void)
 {
 	mutex_init(&psp_devs_lock);
-- 
2.47.1