Merge branch 'xfrm: add extack support to some more message types'

Sabrina Dubroca says:

============
This is the last part of my extack work for xfrm, adding extack
messages to the last remaining operations: NEWSPDINFO, ALLOCSPI,
MIGRATE, NEWAE, DELSA, EXPIRE.

The first patch does a few clean ups on code that will be changed
later on it the series.
============

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

3 files changed, 101 insertions, 37 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index d80519c4e389..9b9e2765363d 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -4333,7 +4333,8 @@ static int migrate_tmpl_match(const struct xfrm_migrate *m, const struct xfrm_tm
 
 /* update endpoint address(es) of template(s) */
 static int xfrm_policy_migrate(struct xfrm_policy *pol,
-			       struct xfrm_migrate *m, int num_migrate)
+			       struct xfrm_migrate *m, int num_migrate,
+			       struct netlink_ext_ack *extack)
 {
 	struct xfrm_migrate *mp;
 	int i, j, n = 0;
@@ -4341,6 +4342,7 @@ static int xfrm_policy_migrate(struct xfrm_policy *pol,
 	write_lock_bh(&pol->lock);
 	if (unlikely(pol->walk.dead)) {
 		/* target policy has been deleted */
+		NL_SET_ERR_MSG(extack, "Target policy not found");
 		write_unlock_bh(&pol->lock);
 		return -ENOENT;
 	}
@@ -4372,17 +4374,22 @@ static int xfrm_policy_migrate(struct xfrm_policy *pol,
 	return 0;
 }
 
-static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
+static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate,
+			      struct netlink_ext_ack *extack)
 {
 	int i, j;
 
-	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH)
+	if (num_migrate < 1 || num_migrate > XFRM_MAX_DEPTH) {
+		NL_SET_ERR_MSG(extack, "Invalid number of SAs to migrate, must be 0 < num <= XFRM_MAX_DEPTH (6)");
 		return -EINVAL;
+	}
 
 	for (i = 0; i < num_migrate; i++) {
 		if (xfrm_addr_any(&m[i].new_daddr, m[i].new_family) ||
-		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family))
+		    xfrm_addr_any(&m[i].new_saddr, m[i].new_family)) {
+			NL_SET_ERR_MSG(extack, "Addresses in the MIGRATE attribute's list cannot be null");
 			return -EINVAL;
+		}
 
 		/* check if there is any duplicated entry */
 		for (j = i + 1; j < num_migrate; j++) {
@@ -4393,8 +4400,10 @@ static int xfrm_migrate_check(const struct xfrm_migrate *m, int num_migrate)
 			    m[i].proto == m[j].proto &&
 			    m[i].mode == m[j].mode &&
 			    m[i].reqid == m[j].reqid &&
-			    m[i].old_family == m[j].old_family)
+			    m[i].old_family == m[j].old_family) {
+				NL_SET_ERR_MSG(extack, "Entries in the MIGRATE attribute's list must be unique");
 				return -EINVAL;
+			}
 		}
 	}
 
@@ -4404,7 +4413,8 @@ 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, u32 if_id)
+		 struct xfrm_encap_tmpl *encap, u32 if_id,
+		 struct netlink_ext_ack *extack)
 {
 	int i, err, nx_cur = 0, nx_new = 0;
 	struct xfrm_policy *pol = NULL;
@@ -4414,16 +4424,20 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 	struct xfrm_migrate *mp;
 
 	/* Stage 0 - sanity checks */
-	if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
+	err = xfrm_migrate_check(m, num_migrate, extack);
+	if (err < 0)
 		goto out;
 
 	if (dir >= XFRM_POLICY_MAX) {
+		NL_SET_ERR_MSG(extack, "Invalid policy direction");
 		err = -EINVAL;
 		goto out;
 	}
 
 	/* Stage 1 - find policy */
-	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id)) == NULL) {
+	pol = xfrm_migrate_policy_find(sel, dir, type, net, if_id);
+	if (!pol) {
+		NL_SET_ERR_MSG(extack, "Target policy not found");
 		err = -ENOENT;
 		goto out;
 	}
@@ -4445,7 +4459,8 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 	}
 
 	/* Stage 3 - update policy */
-	if ((err = xfrm_policy_migrate(pol, m, num_migrate)) < 0)
+	err = xfrm_policy_migrate(pol, m, num_migrate, extack);
+	if (err < 0)
 		goto restore_state;
 
 	/* Stage 4 - delete old state(s) */
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 81df34b3da6e..d0ae17e3bb38 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2017,7 +2017,7 @@ u32 xfrm_get_acqseq(void)
 }
 EXPORT_SYMBOL(xfrm_get_acqseq);
 
-int verify_spi_info(u8 proto, u32 min, u32 max)
+int verify_spi_info(u8 proto, u32 min, u32 max, struct netlink_ext_ack *extack)
 {
 	switch (proto) {
 	case IPPROTO_AH:
@@ -2026,22 +2026,28 @@ int verify_spi_info(u8 proto, u32 min, u32 max)
 
 	case IPPROTO_COMP:
 		/* IPCOMP spi is 16-bits. */
-		if (max >= 0x10000)
+		if (max >= 0x10000) {
+			NL_SET_ERR_MSG(extack, "IPCOMP SPI must be <= 65535");
 			return -EINVAL;
+		}
 		break;
 
 	default:
+		NL_SET_ERR_MSG(extack, "Invalid protocol, must be one of AH, ESP, IPCOMP");
 		return -EINVAL;
 	}
 
-	if (min > max)
+	if (min > max) {
+		NL_SET_ERR_MSG(extack, "Invalid SPI range: min > max");
 		return -EINVAL;
+	}
 
 	return 0;
 }
 EXPORT_SYMBOL(verify_spi_info);
 
-int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
+int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high,
+		   struct netlink_ext_ack *extack)
 {
 	struct net *net = xs_net(x);
 	unsigned int h;
@@ -2053,8 +2059,10 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 	u32 mark = x->mark.v & x->mark.m;
 
 	spin_lock_bh(&x->lock);
-	if (x->km.state == XFRM_STATE_DEAD)
+	if (x->km.state == XFRM_STATE_DEAD) {
+		NL_SET_ERR_MSG(extack, "Target ACQUIRE is in DEAD state");
 		goto unlock;
+	}
 
 	err = 0;
 	if (x->id.spi)
@@ -2065,6 +2073,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 	if (minspi == maxspi) {
 		x0 = xfrm_state_lookup(net, mark, &x->id.daddr, minspi, x->id.proto, x->props.family);
 		if (x0) {
+			NL_SET_ERR_MSG(extack, "Requested SPI is already in use");
 			xfrm_state_put(x0);
 			goto unlock;
 		}
@@ -2089,6 +2098,8 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
 		spin_unlock_bh(&net->xfrm.xfrm_state_lock);
 
 		err = 0;
+	} else {
+		NL_SET_ERR_MSG(extack, "No SPI available in the requested range");
 	}
 
 unlock:
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index e73f9efc54c1..0eb4696661c8 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -515,7 +515,8 @@ static int attach_aead(struct xfrm_state *x, struct nlattr *rta,
 }
 
 static inline int xfrm_replay_verify_len(struct xfrm_replay_state_esn *replay_esn,
-					 struct nlattr *rp)
+					 struct nlattr *rp,
+					 struct netlink_ext_ack *extack)
 {
 	struct xfrm_replay_state_esn *up;
 	unsigned int ulen;
@@ -528,13 +529,25 @@ static inline int xfrm_replay_verify_len(struct xfrm_replay_state_esn *replay_es
 
 	/* Check the overall length and the internal bitmap length to avoid
 	 * potential overflow. */
-	if (nla_len(rp) < (int)ulen ||
-	    xfrm_replay_state_esn_len(replay_esn) != ulen ||
-	    replay_esn->bmp_len != up->bmp_len)
+	if (nla_len(rp) < (int)ulen) {
+		NL_SET_ERR_MSG(extack, "ESN attribute is too short");
 		return -EINVAL;
+	}
+
+	if (xfrm_replay_state_esn_len(replay_esn) != ulen) {
+		NL_SET_ERR_MSG(extack, "New ESN size doesn't match the existing SA's ESN size");
+		return -EINVAL;
+	}
 
-	if (up->replay_window > up->bmp_len * sizeof(__u32) * 8)
+	if (replay_esn->bmp_len != up->bmp_len) {
+		NL_SET_ERR_MSG(extack, "New ESN bitmap size doesn't match the existing SA's ESN bitmap");
 		return -EINVAL;
+	}
+
+	if (up->replay_window > up->bmp_len * sizeof(__u32) * 8) {
+		NL_SET_ERR_MSG(extack, "ESN replay window is longer than the bitmap");
+		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -862,12 +875,12 @@ static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh,
 		goto out;
 
 	if (xfrm_state_kern(x)) {
+		NL_SET_ERR_MSG(extack, "SA is in use by tunnels");
 		err = -EPERM;
 		goto out;
 	}
 
 	err = xfrm_state_delete(x);
-
 	if (err < 0)
 		goto out;
 
@@ -1354,20 +1367,28 @@ static int xfrm_set_spdinfo(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (attrs[XFRMA_SPD_IPV4_HTHRESH]) {
 		struct nlattr *rta = attrs[XFRMA_SPD_IPV4_HTHRESH];
 
-		if (nla_len(rta) < sizeof(*thresh4))
+		if (nla_len(rta) < sizeof(*thresh4)) {
+			NL_SET_ERR_MSG(extack, "Invalid SPD_IPV4_HTHRESH attribute length");
 			return -EINVAL;
+		}
 		thresh4 = nla_data(rta);
-		if (thresh4->lbits > 32 || thresh4->rbits > 32)
+		if (thresh4->lbits > 32 || thresh4->rbits > 32) {
+			NL_SET_ERR_MSG(extack, "Invalid hash threshold (must be <= 32 for IPv4)");
 			return -EINVAL;
+		}
 	}
 	if (attrs[XFRMA_SPD_IPV6_HTHRESH]) {
 		struct nlattr *rta = attrs[XFRMA_SPD_IPV6_HTHRESH];
 
-		if (nla_len(rta) < sizeof(*thresh6))
+		if (nla_len(rta) < sizeof(*thresh6)) {
+			NL_SET_ERR_MSG(extack, "Invalid SPD_IPV6_HTHRESH attribute length");
 			return -EINVAL;
+		}
 		thresh6 = nla_data(rta);
-		if (thresh6->lbits > 128 || thresh6->rbits > 128)
+		if (thresh6->lbits > 128 || thresh6->rbits > 128) {
+			NL_SET_ERR_MSG(extack, "Invalid hash threshold (must be <= 128 for IPv6)");
 			return -EINVAL;
+		}
 	}
 
 	if (thresh4 || thresh6) {
@@ -1510,7 +1531,7 @@ static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh,
 	u32 if_id = 0;
 
 	p = nlmsg_data(nlh);
-	err = verify_spi_info(p->info.id.proto, p->min, p->max);
+	err = verify_spi_info(p->info.id.proto, p->min, p->max, extack);
 	if (err)
 		goto out_noput;
 
@@ -1538,10 +1559,12 @@ static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh,
 				  &p->info.saddr, 1,
 				  family);
 	err = -ENOENT;
-	if (x == NULL)
+	if (!x) {
+		NL_SET_ERR_MSG(extack, "Target ACQUIRE not found");
 		goto out_noput;
+	}
 
-	err = xfrm_alloc_spi(x, p->min, p->max);
+	err = xfrm_alloc_spi(x, p->min, p->max, extack);
 	if (err)
 		goto out;
 
@@ -2433,12 +2456,16 @@ static int xfrm_new_ae(struct sk_buff *skb, struct nlmsghdr *nlh,
 	struct nlattr *et = attrs[XFRMA_ETIMER_THRESH];
 	struct nlattr *rt = attrs[XFRMA_REPLAY_THRESH];
 
-	if (!lt && !rp && !re && !et && !rt)
+	if (!lt && !rp && !re && !et && !rt) {
+		NL_SET_ERR_MSG(extack, "Missing required attribute for AE");
 		return err;
+	}
 
 	/* pedantic mode - thou shalt sayeth replaceth */
-	if (!(nlh->nlmsg_flags&NLM_F_REPLACE))
+	if (!(nlh->nlmsg_flags & NLM_F_REPLACE)) {
+		NL_SET_ERR_MSG(extack, "NLM_F_REPLACE flag is required");
 		return err;
+	}
 
 	mark = xfrm_mark_get(attrs, &m);
 
@@ -2446,10 +2473,12 @@ static int xfrm_new_ae(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (x == NULL)
 		return -ESRCH;
 
-	if (x->km.state != XFRM_STATE_VALID)
+	if (x->km.state != XFRM_STATE_VALID) {
+		NL_SET_ERR_MSG(extack, "SA must be in VALID state");
 		goto out;
+	}
 
-	err = xfrm_replay_verify_len(x->replay_esn, re);
+	err = xfrm_replay_verify_len(x->replay_esn, re, extack);
 	if (err)
 		goto out;
 
@@ -2584,8 +2613,11 @@ static int xfrm_add_sa_expire(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	spin_lock_bh(&x->lock);
 	err = -EINVAL;
-	if (x->km.state != XFRM_STATE_VALID)
+	if (x->km.state != XFRM_STATE_VALID) {
+		NL_SET_ERR_MSG(extack, "SA must be in VALID state");
 		goto out;
+	}
+
 	km_state_expired(x, ue->hard, nlh->nlmsg_pid);
 
 	if (ue->hard) {
@@ -2665,7 +2697,8 @@ nomem:
 #ifdef CONFIG_XFRM_MIGRATE
 static int copy_from_user_migrate(struct xfrm_migrate *ma,
 				  struct xfrm_kmaddress *k,
-				  struct nlattr **attrs, int *num)
+				  struct nlattr **attrs, int *num,
+				  struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_MIGRATE];
 	struct xfrm_user_migrate *um;
@@ -2684,8 +2717,10 @@ static int copy_from_user_migrate(struct xfrm_migrate *ma,
 	um = nla_data(rt);
 	num_migrate = nla_len(rt) / sizeof(*um);
 
-	if (num_migrate <= 0 || num_migrate > XFRM_MAX_DEPTH)
+	if (num_migrate <= 0 || num_migrate > XFRM_MAX_DEPTH) {
+		NL_SET_ERR_MSG(extack, "Invalid number of SAs to migrate, must be 0 < num <= XFRM_MAX_DEPTH (6)");
 		return -EINVAL;
+	}
 
 	for (i = 0; i < num_migrate; i++, um++, ma++) {
 		memcpy(&ma->old_daddr, &um->old_daddr, sizeof(ma->old_daddr));
@@ -2718,8 +2753,10 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh,
 	struct xfrm_encap_tmpl  *encap = NULL;
 	u32 if_id = 0;
 
-	if (attrs[XFRMA_MIGRATE] == NULL)
+	if (!attrs[XFRMA_MIGRATE]) {
+		NL_SET_ERR_MSG(extack, "Missing required MIGRATE attribute");
 		return -EINVAL;
+	}
 
 	kmp = attrs[XFRMA_KMADDRESS] ? &km : NULL;
 
@@ -2727,7 +2764,7 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (err)
 		return err;
 
-	err = copy_from_user_migrate((struct xfrm_migrate *)m, kmp, attrs, &n);
+	err = copy_from_user_migrate(m, kmp, attrs, &n, extack);
 	if (err)
 		return err;
 
@@ -2744,7 +2781,8 @@ static int xfrm_do_migrate(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (attrs[XFRMA_IF_ID])
 		if_id = nla_get_u32(attrs[XFRMA_IF_ID]);
 
-	err = xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp, net, encap, if_id);
+	err = xfrm_migrate(&pi->sel, pi->dir, type, m, n, kmp, net, encap,
+			   if_id, extack);
 
 	kfree(encap);