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Message-ID: <20231110113719.3055788-7-chopps@chopps.org>
Date: Fri, 10 Nov 2023 06:37:17 -0500
From: Christian Hopps <chopps@...pps.org>
To: devel@...ux-ipsec.org
Cc: Steffen Klassert <steffen.klassert@...unet.com>,
netdev@...r.kernel.org,
Christian Hopps <chopps@...n.net>
Subject: [RFC ipsec-next 6/8] iptfs: xfrm: Add mode_cbs module functionality
From: Christian Hopps <chopps@...n.net>
Add a set of callbacks xfrm_mode_cbs to xfrm_state. These callbacks
enable the addition of new xfrm modes, such as IP-TFS to be defined
in modules.
Signed-off-by: Christian Hopps <chopps@...n.net>
---
include/net/xfrm.h | 36 ++++++++++++++++++++++++++++++++++++
net/xfrm/xfrm_device.c | 3 ++-
net/xfrm/xfrm_input.c | 14 ++++++++++++--
net/xfrm/xfrm_output.c | 9 +++++++--
net/xfrm/xfrm_policy.c | 18 +++++++++++-------
net/xfrm/xfrm_state.c | 41 +++++++++++++++++++++++++++++++++++++++++
net/xfrm/xfrm_user.c | 10 ++++++++++
7 files changed, 119 insertions(+), 12 deletions(-)
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index d2e87344d175..aeeadadc9545 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -204,6 +204,7 @@ struct xfrm_state {
u16 family;
xfrm_address_t saddr;
int header_len;
+ int enc_hdr_len;
int trailer_len;
u32 extra_flags;
struct xfrm_mark smark;
@@ -289,6 +290,9 @@ struct xfrm_state {
/* Private data of this transformer, format is opaque,
* interpreted by xfrm_type methods. */
void *data;
+
+ const struct xfrm_mode_cbs *mode_cbs;
+ void *mode_data;
};
static inline struct net *xs_net(struct xfrm_state *x)
@@ -441,6 +445,38 @@ struct xfrm_type_offload {
int xfrm_register_type_offload(const struct xfrm_type_offload *type, unsigned short family);
void xfrm_unregister_type_offload(const struct xfrm_type_offload *type, unsigned short family);
+struct xfrm_mode_cbs {
+ struct module *owner;
+ /* Add/delete state in the new xfrm_state in `x`. */
+ int (*create_state)(struct xfrm_state *x);
+ void (*delete_state)(struct xfrm_state *x);
+
+ /* Called while handling the user netlink options. */
+ int (*user_init)(struct net *net, struct xfrm_state *x,
+ struct nlattr **attrs);
+ int (*copy_to_user)(struct xfrm_state *x, struct sk_buff *skb);
+
+ u32 (*get_inner_mtu)(struct xfrm_state *x, int outer_mtu);
+
+ /* Called to handle received xfrm (egress) packets. */
+ int (*input)(struct xfrm_state *x, struct sk_buff *skb);
+
+ /* Placed in dst_output of the dst when an xfrm_state is bound. */
+ int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
+
+ /**
+ * Prepare the skb for output for the given mode. Returns:
+ * Error value, if 0 then skb values should be as follows:
+ * transport_header should point at ESP header
+ * network_header should point at Outer IP header
+ * mac_header should point at protocol/nexthdr of the outer IP
+ */
+ int (*prepare_output)(struct xfrm_state *x, struct sk_buff *skb);
+};
+
+int xfrm_register_mode_cbs(u8 mode, const struct xfrm_mode_cbs *mode_cbs);
+void xfrm_unregister_mode_cbs(u8 mode);
+
static inline int xfrm_af2proto(unsigned int family)
{
switch(family) {
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 3784534c9185..8b848540ea47 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -42,7 +42,8 @@ static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
skb->transport_header = skb->network_header + hsize;
skb_reset_mac_len(skb);
- pskb_pull(skb, skb->mac_len + x->props.header_len);
+ pskb_pull(skb,
+ skb->mac_len + x->props.header_len - x->props.enc_hdr_len);
}
static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index bd4ce21d76d7..824f7b7f90e0 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -437,6 +437,9 @@ static int xfrm_inner_mode_input(struct xfrm_state *x,
WARN_ON_ONCE(1);
break;
default:
+ if (x->mode_cbs && x->mode_cbs->input)
+ return x->mode_cbs->input(x, skb);
+
WARN_ON_ONCE(1);
break;
}
@@ -479,6 +482,10 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
family = x->props.family;
+ /* An encap_type of -3 indicates reconstructed inner packet */
+ if (encap_type == -3)
+ goto resume_decapped;
+
/* An encap_type of -1 indicates async resumption. */
if (encap_type == -1) {
async = 1;
@@ -660,11 +667,14 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
- if (xfrm_inner_mode_input(x, skb)) {
+ err = xfrm_inner_mode_input(x, skb);
+ if (err == -EINPROGRESS)
+ return 0;
+ else if (err) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
goto drop;
}
-
+resume_decapped:
if (x->outer_mode.flags & XFRM_MODE_FLAG_TUNNEL) {
decaps = 1;
break;
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 662c83beb345..4390c111410d 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -280,7 +280,9 @@ static int xfrm4_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
skb_set_inner_network_header(skb, skb_network_offset(skb));
skb_set_inner_transport_header(skb, skb_transport_offset(skb));
- skb_set_network_header(skb, -x->props.header_len);
+ /* backup to add space for the outer encap */
+ skb_set_network_header(skb,
+ -x->props.header_len + x->props.enc_hdr_len);
skb->mac_header = skb->network_header +
offsetof(struct iphdr, protocol);
skb->transport_header = skb->network_header + sizeof(*top_iph);
@@ -325,7 +327,8 @@ static int xfrm6_tunnel_encap_add(struct xfrm_state *x, struct sk_buff *skb)
skb_set_inner_network_header(skb, skb_network_offset(skb));
skb_set_inner_transport_header(skb, skb_transport_offset(skb));
- skb_set_network_header(skb, -x->props.header_len);
+ skb_set_network_header(skb,
+ -x->props.header_len + x->props.enc_hdr_len);
skb->mac_header = skb->network_header +
offsetof(struct ipv6hdr, nexthdr);
skb->transport_header = skb->network_header + sizeof(*top_iph);
@@ -472,6 +475,8 @@ static int xfrm_outer_mode_output(struct xfrm_state *x, struct sk_buff *skb)
WARN_ON_ONCE(1);
break;
default:
+ if (x->mode_cbs->prepare_output)
+ return x->mode_cbs->prepare_output(x, skb);
WARN_ON_ONCE(1);
break;
}
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index d2dddc570f4f..3220b01121f3 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2707,13 +2707,17 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
dst1->input = dst_discard;
- rcu_read_lock();
- afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
- if (likely(afinfo))
- dst1->output = afinfo->output;
- else
- dst1->output = dst_discard_out;
- rcu_read_unlock();
+ if (xfrm[i]->mode_cbs && xfrm[i]->mode_cbs->output) {
+ dst1->output = xfrm[i]->mode_cbs->output;
+ } else {
+ rcu_read_lock();
+ afinfo = xfrm_state_afinfo_get_rcu(inner_mode->family);
+ if (likely(afinfo))
+ dst1->output = afinfo->output;
+ else
+ dst1->output = dst_discard_out;
+ rcu_read_unlock();
+ }
xdst_prev = xdst;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index bda5327bf34d..f5e1a17ebf74 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -513,6 +513,36 @@ static const struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family)
return NULL;
}
+static struct xfrm_mode_cbs xfrm_mode_cbs_map[XFRM_MODE_MAX];
+
+int xfrm_register_mode_cbs(u8 mode, const struct xfrm_mode_cbs *mode_cbs)
+{
+ if (mode >= XFRM_MODE_MAX)
+ return -EINVAL;
+
+ xfrm_mode_cbs_map[mode] = *mode_cbs;
+ return 0;
+}
+EXPORT_SYMBOL(xfrm_register_mode_cbs);
+
+void xfrm_unregister_mode_cbs(u8 mode)
+{
+ if (mode >= XFRM_MODE_MAX)
+ return;
+
+ memset(&xfrm_mode_cbs_map[mode], 0, sizeof(xfrm_mode_cbs_map[mode]));
+}
+EXPORT_SYMBOL(xfrm_unregister_mode_cbs);
+
+static const struct xfrm_mode_cbs *xfrm_get_mode_cbs(u8 mode)
+{
+ if (mode >= XFRM_MODE_MAX)
+ return NULL;
+ if (mode == XFRM_MODE_IPTFS && !xfrm_mode_cbs_map[mode].create_state)
+ request_module("xfrm-iptfs");
+ return &xfrm_mode_cbs_map[mode];
+}
+
void xfrm_state_free(struct xfrm_state *x)
{
kmem_cache_free(xfrm_state_cache, x);
@@ -521,6 +551,8 @@ EXPORT_SYMBOL(xfrm_state_free);
static void ___xfrm_state_destroy(struct xfrm_state *x)
{
+ if (x->mode_cbs && x->mode_cbs->delete_state)
+ x->mode_cbs->delete_state(x);
hrtimer_cancel(&x->mtimer);
del_timer_sync(&x->rtimer);
kfree(x->aead);
@@ -2765,6 +2797,9 @@ u32 xfrm_state_mtu(struct xfrm_state *x, int mtu)
case XFRM_MODE_TUNNEL:
break;
default:
+ if (x->mode_cbs && x->mode_cbs->get_inner_mtu)
+ return x->mode_cbs->get_inner_mtu(x, mtu);
+
WARN_ON_ONCE(1);
break;
}
@@ -2850,6 +2885,12 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload,
goto error;
}
+ x->mode_cbs = xfrm_get_mode_cbs(x->props.mode);
+ if (x->mode_cbs && x->mode_cbs->create_state) {
+ err = x->mode_cbs->create_state(x);
+ if (err)
+ goto error;
+ }
error:
return err;
}
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index ed95772bbd3f..8a504331e369 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -779,6 +779,12 @@ static struct xfrm_state *xfrm_state_construct(struct net *net,
goto error;
}
+ if (x->mode_cbs && x->mode_cbs->user_init) {
+ err = x->mode_cbs->user_init(net, x, attrs);
+ if (err)
+ goto error;
+ }
+
return x;
error:
@@ -1192,6 +1198,10 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
if (ret)
goto out;
}
+ if (x->mode_cbs && x->mode_cbs->copy_to_user)
+ ret = x->mode_cbs->copy_to_user(x, skb);
+ if (ret)
+ goto out;
if (x->mapping_maxage)
ret = nla_put_u32(skb, XFRMA_MTIMER_THRESH, x->mapping_maxage);
out:
--
2.42.0
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