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: Add populate from packet (PFP) support

PATCH In review Tyler Hicks 2 participants 2 messages Dec 12, 2007

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Networking Network drivers Networking IPsec
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Tyler Hicks

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#0 lore raw

PATCH 1/1 : Add populate from packet (PFP) support

RFC 4301 requires us to associate each SPD entry with a set of flags to determine how to assign the selector values when creating a new SAD entry.

Each selector in the new xfrm_state can either be assigned using the corresponding selector in the xfrm_policy or with the corresponding value in the flowi. Prior to this patch, the fields in the flowi were always used.

Signed-off-by Tyler Hicks <[email protected]>
include/linux/xfrm.h +5 -0
index b58adc5..ce6b1b5 100644
@@ -362,6 +362,11 @@ struct xfrm_userpolicy_info {
 #define XFRM_POLICY_BLOCK	1
 	__u8				flags;
 #define XFRM_POLICY_LOCALOK	1	/* Allow user to override global policy */
+#define XFRM_POLICY_PFP_SADDR	2
+#define XFRM_POLICY_PFP_DADDR	4
+#define XFRM_POLICY_PFP_PROTO	8
+#define XFRM_POLICY_PFP_SPORT	16
+#define XFRM_POLICY_PFP_DPORT	32
 	__u8				share;
 };
include/net/xfrm.h +5 -2
index 58dfa82..5a039a2 100644
@@ -261,9 +261,12 @@ struct xfrm_state_afinfo {
 	struct xfrm_type	*type_map[IPPROTO_MAX];
 	struct xfrm_mode	*mode_map[XFRM_MODE_MAX];
 	int			(*init_flags)(struct xfrm_state *x);
-	void			(*init_tempsel)(struct xfrm_state *x, struct flowi *fl,
+	void			(*init_tempsel)(struct xfrm_state *x,
+						struct flowi *fl,
 						struct xfrm_tmpl *tmpl,
-						xfrm_address_t *daddr, xfrm_address_t *saddr);
+						struct xfrm_policy *pol,
+						xfrm_address_t *daddr,
+						xfrm_address_t *saddr);
 	int			(*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
 	int			(*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
 	int			(*output)(struct sk_buff *skb);
net/ipv4/xfrm4_state.c +31 -10

49 lines not on this page · raw message

net/ipv6/xfrm6_state.c +33 -10

53 lines not on this page · raw message

net/xfrm/xfrm_state.c +3 -3
index 224b44e..2dab50e 100644
@@ -654,14 +654,14 @@ EXPORT_SYMBOL(xfrm_sad_getinfo);
 
 static int
 xfrm_init_tempsel(struct xfrm_state *x, struct flowi *fl,
-		  struct xfrm_tmpl *tmpl,
+		  struct xfrm_tmpl *tmpl, struct xfrm_policy *pol,
 		  xfrm_address_t *daddr, xfrm_address_t *saddr,
 		  unsigned short family)
 {
 	struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
 	if (!afinfo)
 		return -1;
-	afinfo->init_tempsel(x, fl, tmpl, daddr, saddr);
+	afinfo->init_tempsel(x, fl, tmpl, pol, daddr, saddr);
 	xfrm_state_put_afinfo(afinfo);
 	return 0;
 }

@@ -824,7 +824,7 @@ xfrm_state_find(xfrm_address_t *daddr, xfrm_address_t *saddr,
 		}
 		/* Initialize temporary selector matching only
 		 * to current session. */
-		xfrm_init_tempsel(x, fl, tmpl, daddr, saddr, family);
+		xfrm_init_tempsel(x, fl, tmpl, pol, daddr, saddr, family);
 
 		error = security_xfrm_state_alloc_acquire(x, pol->security, fl->secid);
 		if (error) {
Signature · 1 line
1.5.3.4
maintainer
#1 lore raw
Quoted 9 lines · Tyler Hicks

RFC 4301 requires us to associate each SPD entry with a set of flags to determine how to assign the selector values when creating a new SAD entry.

Each selector in the new xfrm_state can either be assigned using the corresponding selector in the xfrm_policy or with the corresponding value in the flowi. Prior to this patch, the fields in the flowi were always used.

Signed-off-by Tyler Hicks <[email protected]>

Thanks for the patch Tyler!

I think the kernel is fine as it is. What we're doing is generating the most specific selector possible for the larval SA and which lets the KM do whatever it wants.

What RFC 4301 is asking for is for the mature SAs to have their selectors either populated from the policy or the packet.

So for PFP the KM should fill out its SA selector according to its PFP flags. In other words we don't need PFP flags in the kernel at all.

net/ipv4/xfrm4_state.c static int xfrm4_init_flags(struct xfrm_state *x) · line 55

Quoted 6 lines
net/ipv4/xfrm4_state.c +6 -0
+	if (pol->flags & XFRM_POLICY_PFP_SPORT) {
+		x->sel.sport = xfrm_flowi_sport(fl);
+		x->sel.sport_mask = htons(0xffff);
+	} else {
+		x->sel.sport = pol->selector.sport;
+		x->sel.sport = pol->selector.sport_mask;

There's a typo here.

Cheers,

Signature · 4 lines
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