From b58b1f563ab78955d37e9e43e02790a85c66ac05 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 14 Mar 2022 11:38:22 +0100 Subject: [PATCH] xfrm: rework default policy structure This is a follow up of commit f8d858e607b2 ("xfrm: make user policy API complete"). The goal is to align userland API to the internal structures. Signed-off-by: Nicolas Dichtel Reviewed-by: Antony Antony Signed-off-by: Steffen Klassert --- include/net/netns/xfrm.h | 6 +---- include/net/xfrm.h | 48 +++++++++++++++------------------------- net/xfrm/xfrm_policy.c | 10 ++++++--- net/xfrm/xfrm_user.c | 43 +++++++++++++++-------------------- 4 files changed, 44 insertions(+), 63 deletions(-) diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h index 947733a639a6..bd7c3be4af5d 100644 --- a/include/net/netns/xfrm.h +++ b/include/net/netns/xfrm.h @@ -66,11 +66,7 @@ struct netns_xfrm { int sysctl_larval_drop; u32 sysctl_acq_expires; - u8 policy_default; -#define XFRM_POL_DEFAULT_IN 1 -#define XFRM_POL_DEFAULT_OUT 2 -#define XFRM_POL_DEFAULT_FWD 4 -#define XFRM_POL_DEFAULT_MASK 7 + u8 policy_default[XFRM_POLICY_MAX]; #ifdef CONFIG_SYSCTL struct ctl_table_header *sysctl_hdr; diff --git a/include/net/xfrm.h b/include/net/xfrm.h index fdb41e8bb626..1541ca0cb13c 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1081,25 +1081,18 @@ xfrm_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x, un } #ifdef CONFIG_XFRM -static inline bool -xfrm_default_allow(struct net *net, int dir) -{ - u8 def = net->xfrm.policy_default; - - switch (dir) { - case XFRM_POLICY_IN: - return def & XFRM_POL_DEFAULT_IN ? false : true; - case XFRM_POLICY_OUT: - return def & XFRM_POL_DEFAULT_OUT ? false : true; - case XFRM_POLICY_FWD: - return def & XFRM_POL_DEFAULT_FWD ? false : true; - } - return false; -} - int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb, unsigned short family); +static inline bool __xfrm_check_nopolicy(struct net *net, struct sk_buff *skb, + int dir) +{ + if (!net->xfrm.policy_count[dir] && !secpath_exists(skb)) + return net->xfrm.policy_default[dir] == XFRM_USERPOLICY_ACCEPT; + + return false; +} + static inline int __xfrm_policy_check2(struct sock *sk, int dir, struct sk_buff *skb, unsigned int family, int reverse) @@ -1110,13 +1103,9 @@ static inline int __xfrm_policy_check2(struct sock *sk, int dir, if (sk && sk->sk_policy[XFRM_POLICY_IN]) return __xfrm_policy_check(sk, ndir, skb, family); - if (xfrm_default_allow(net, dir)) - return (!net->xfrm.policy_count[dir] && !secpath_exists(skb)) || - (skb_dst(skb) && (skb_dst(skb)->flags & DST_NOPOLICY)) || - __xfrm_policy_check(sk, ndir, skb, family); - else - return (skb_dst(skb) && (skb_dst(skb)->flags & DST_NOPOLICY)) || - __xfrm_policy_check(sk, ndir, skb, family); + return __xfrm_check_nopolicy(net, skb, dir) || + (skb_dst(skb) && (skb_dst(skb)->flags & DST_NOPOLICY)) || + __xfrm_policy_check(sk, ndir, skb, family); } static inline int xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, unsigned short family) @@ -1168,13 +1157,12 @@ static inline int xfrm_route_forward(struct sk_buff *skb, unsigned short family) { struct net *net = dev_net(skb->dev); - if (xfrm_default_allow(net, XFRM_POLICY_OUT)) - return !net->xfrm.policy_count[XFRM_POLICY_OUT] || - (skb_dst(skb)->flags & DST_NOXFRM) || - __xfrm_route_forward(skb, family); - else - return (skb_dst(skb)->flags & DST_NOXFRM) || - __xfrm_route_forward(skb, family); + if (!net->xfrm.policy_count[XFRM_POLICY_OUT] && + net->xfrm.policy_default[XFRM_POLICY_OUT] == XFRM_USERPOLICY_ACCEPT) + return true; + + return (skb_dst(skb)->flags & DST_NOXFRM) || + __xfrm_route_forward(skb, family); } static inline int xfrm4_route_forward(struct sk_buff *skb) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 04d1ce9b510f..01fe1e9cff86 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3158,7 +3158,7 @@ ok: nopol: if (!(dst_orig->dev->flags & IFF_LOOPBACK) && - !xfrm_default_allow(net, dir)) { + net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) { err = -EPERM; goto error; } @@ -3569,7 +3569,7 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, } if (!pol) { - if (!xfrm_default_allow(net, dir)) { + if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK) { XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOPOLS); return 0; } @@ -3629,7 +3629,8 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, } xfrm_nr = ti; - if (!xfrm_default_allow(net, dir) && !xfrm_nr) { + if (net->xfrm.policy_default[dir] == XFRM_USERPOLICY_BLOCK && + !xfrm_nr) { XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES); goto reject; } @@ -4118,6 +4119,9 @@ static int __net_init xfrm_net_init(struct net *net) spin_lock_init(&net->xfrm.xfrm_policy_lock); seqcount_spinlock_init(&net->xfrm.xfrm_policy_hash_generation, &net->xfrm.xfrm_policy_lock); mutex_init(&net->xfrm.xfrm_cfg_mutex); + net->xfrm.policy_default[XFRM_POLICY_IN] = XFRM_USERPOLICY_ACCEPT; + net->xfrm.policy_default[XFRM_POLICY_FWD] = XFRM_USERPOLICY_ACCEPT; + net->xfrm.policy_default[XFRM_POLICY_OUT] = XFRM_USERPOLICY_ACCEPT; rv = xfrm_statistics_init(net); if (rv < 0) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 8cd6c8129004..2f6b64cf0975 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2009,12 +2009,9 @@ static int xfrm_notify_userpolicy(struct net *net) } up = nlmsg_data(nlh); - up->in = net->xfrm.policy_default & XFRM_POL_DEFAULT_IN ? - XFRM_USERPOLICY_BLOCK : XFRM_USERPOLICY_ACCEPT; - up->fwd = net->xfrm.policy_default & XFRM_POL_DEFAULT_FWD ? - XFRM_USERPOLICY_BLOCK : XFRM_USERPOLICY_ACCEPT; - up->out = net->xfrm.policy_default & XFRM_POL_DEFAULT_OUT ? - XFRM_USERPOLICY_BLOCK : XFRM_USERPOLICY_ACCEPT; + up->in = net->xfrm.policy_default[XFRM_POLICY_IN]; + up->fwd = net->xfrm.policy_default[XFRM_POLICY_FWD]; + up->out = net->xfrm.policy_default[XFRM_POLICY_OUT]; nlmsg_end(skb, nlh); @@ -2025,26 +2022,26 @@ static int xfrm_notify_userpolicy(struct net *net) return err; } +static bool xfrm_userpolicy_is_valid(__u8 policy) +{ + return policy == XFRM_USERPOLICY_BLOCK || + policy == XFRM_USERPOLICY_ACCEPT; +} + static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh, struct nlattr **attrs) { struct net *net = sock_net(skb->sk); struct xfrm_userpolicy_default *up = nlmsg_data(nlh); - if (up->in == XFRM_USERPOLICY_BLOCK) - net->xfrm.policy_default |= XFRM_POL_DEFAULT_IN; - else if (up->in == XFRM_USERPOLICY_ACCEPT) - net->xfrm.policy_default &= ~XFRM_POL_DEFAULT_IN; + if (xfrm_userpolicy_is_valid(up->in)) + net->xfrm.policy_default[XFRM_POLICY_IN] = up->in; - if (up->fwd == XFRM_USERPOLICY_BLOCK) - net->xfrm.policy_default |= XFRM_POL_DEFAULT_FWD; - else if (up->fwd == XFRM_USERPOLICY_ACCEPT) - net->xfrm.policy_default &= ~XFRM_POL_DEFAULT_FWD; + if (xfrm_userpolicy_is_valid(up->fwd)) + net->xfrm.policy_default[XFRM_POLICY_FWD] = up->fwd; - if (up->out == XFRM_USERPOLICY_BLOCK) - net->xfrm.policy_default |= XFRM_POL_DEFAULT_OUT; - else if (up->out == XFRM_USERPOLICY_ACCEPT) - net->xfrm.policy_default &= ~XFRM_POL_DEFAULT_OUT; + if (xfrm_userpolicy_is_valid(up->out)) + net->xfrm.policy_default[XFRM_POLICY_OUT] = up->out; rt_genid_bump_all(net); @@ -2074,13 +2071,9 @@ static int xfrm_get_default(struct sk_buff *skb, struct nlmsghdr *nlh, } r_up = nlmsg_data(r_nlh); - - r_up->in = net->xfrm.policy_default & XFRM_POL_DEFAULT_IN ? - XFRM_USERPOLICY_BLOCK : XFRM_USERPOLICY_ACCEPT; - r_up->fwd = net->xfrm.policy_default & XFRM_POL_DEFAULT_FWD ? - XFRM_USERPOLICY_BLOCK : XFRM_USERPOLICY_ACCEPT; - r_up->out = net->xfrm.policy_default & XFRM_POL_DEFAULT_OUT ? - XFRM_USERPOLICY_BLOCK : XFRM_USERPOLICY_ACCEPT; + r_up->in = net->xfrm.policy_default[XFRM_POLICY_IN]; + r_up->fwd = net->xfrm.policy_default[XFRM_POLICY_FWD]; + r_up->out = net->xfrm.policy_default[XFRM_POLICY_OUT]; nlmsg_end(r_skb, r_nlh); return nlmsg_unicast(net->xfrm.nlsk, r_skb, portid);