From c1aca3080e382886e2e58e809787441984a2f89b Mon Sep 17 00:00:00 2001 From: Yan Yan Date: Tue, 18 Jan 2022 16:00:13 -0800 Subject: xfrm: Check if_id in xfrm_migrate This patch enables distinguishing SAs and SPs based on if_id during the xfrm_migrate flow. This ensures support for xfrm interfaces throughout the SA/SP lifecycle. When there are multiple existing SPs with the same direction, the same xfrm_selector and different endpoint addresses, xfrm_migrate might fail with ENODATA. Specifically, the code path for performing xfrm_migrate is: Stage 1: find policy to migrate with xfrm_migrate_policy_find(sel, dir, type, net) Stage 2: find and update state(s) with xfrm_migrate_state_find(mp, net) Stage 3: update endpoint address(es) of template(s) with xfrm_policy_migrate(pol, m, num_migrate) Currently "Stage 1" always returns the first xfrm_policy that matches, and "Stage 3" looks for the xfrm_tmpl that matches the old endpoint address. Thus if there are multiple xfrm_policy with same selector, direction, type and net, "Stage 1" might rertun a wrong xfrm_policy and "Stage 3" will fail with ENODATA because it cannot find a xfrm_tmpl with the matching endpoint address. The fix is to allow userspace to pass an if_id and add if_id to the matching rule in Stage 1 and Stage 2 since if_id is a unique ID for xfrm_policy and xfrm_state. For compatibility, if_id will only be checked if the attribute is set. Tested with additions to Android's kernel unit test suite: https://android-review.googlesource.com/c/kernel/tests/+/1668886 Signed-off-by: Yan Yan Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'net/xfrm/xfrm_policy.c') diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 04d1ce9b510f..882526159d3a 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -4256,7 +4256,7 @@ static bool xfrm_migrate_selector_match(const struct xfrm_selector *sel_cmp, } static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector *sel, - u8 dir, u8 type, struct net *net) + u8 dir, u8 type, struct net *net, u32 if_id) { struct xfrm_policy *pol, *ret = NULL; struct hlist_head *chain; @@ -4265,7 +4265,8 @@ static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector * spin_lock_bh(&net->xfrm.xfrm_policy_lock); chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir); hlist_for_each_entry(pol, chain, bydst) { - if (xfrm_migrate_selector_match(sel, &pol->selector) && + if ((if_id == 0 || pol->if_id == if_id) && + xfrm_migrate_selector_match(sel, &pol->selector) && pol->type == type) { ret = pol; priority = ret->priority; @@ -4277,7 +4278,8 @@ static struct xfrm_policy *xfrm_migrate_policy_find(const struct xfrm_selector * if ((pol->priority >= priority) && ret) break; - if (xfrm_migrate_selector_match(sel, &pol->selector) && + if ((if_id == 0 || pol->if_id == if_id) && + xfrm_migrate_selector_match(sel, &pol->selector) && pol->type == type) { ret = pol; break; @@ -4393,7 +4395,7 @@ static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate) int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, struct xfrm_migrate *m, int num_migrate, struct xfrm_kmaddress *k, struct net *net, - struct xfrm_encap_tmpl *encap) + struct xfrm_encap_tmpl *encap, u32 if_id) { int i, err, nx_cur = 0, nx_new = 0; struct xfrm_policy *pol = NULL; @@ -4412,14 +4414,14 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, } /* Stage 1 - find policy */ - if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) { + if ((pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id)) == NULL) { err = -ENOENT; goto out; } /* Stage 2 - find and update state(s) */ for (i = 0, mp = m; i < num_migrate; i++, mp++) { - if ((x = xfrm_migrate_state_find(mp, net))) { + if ((x = xfrm_migrate_state_find(mp, net, if_id))) { x_cur[nx_cur] = x; nx_cur++; xc = xfrm_state_migrate(x, mp, encap); -- cgit v1.2.3