From: Johannes Berg <johannes.berg@xxxxxxxxx>
Add the base infrastructure and UAPI for netlink
extended ACK reporting. All "manual" calls to
netlink_ack() pass NULL for now and thus don't
get extended ACK reporting.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
crypto/crypto_user.c | 3 +-
drivers/infiniband/core/netlink.c | 5 +--
drivers/scsi/scsi_netlink.c | 2 +-
include/linux/netlink.h | 32 ++++++++++++++++-
include/net/netlink.h | 3 +-
include/uapi/linux/netlink.h | 24 +++++++++++++
kernel/audit.c | 2 +-
net/core/rtnetlink.c | 3 +-
net/core/sock_diag.c | 3 +-
net/hsr/hsr_netlink.c | 4 +--
net/netfilter/ipset/ip_set_core.c | 2 +-
net/netfilter/nfnetlink.c | 22 ++++++------
net/netlink/af_netlink.c | 72 ++++++++++++++++++++++++++++++++++-----
net/netlink/af_netlink.h | 1 +
net/netlink/genetlink.c | 3 +-
net/xfrm/xfrm_user.c | 3 +-
16 files changed, 151 insertions(+), 33 deletions(-)
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index a90404a0c5ff..4a44830741c1 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -483,7 +483,8 @@ static const struct crypto_link {
[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
};
-static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
struct nlattr *attrs[CRYPTOCFGA_MAX+1];
const struct crypto_link *link;
diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c
index 10469b0088b5..b784055423c8 100644
--- a/drivers/infiniband/core/netlink.c
+++ b/drivers/infiniband/core/netlink.c
@@ -146,7 +146,8 @@ int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
}
EXPORT_SYMBOL(ibnl_put_attr);
-static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
struct ibnl_client *client;
int type = nlh->nlmsg_type;
@@ -209,7 +210,7 @@ static void ibnl_rcv_reply_skb(struct sk_buff *skb)
if (nlh->nlmsg_flags & NLM_F_REQUEST)
return;
- ibnl_rcv_msg(skb, nlh);
+ ibnl_rcv_msg(skb, nlh, NULL);
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
if (msglen > skb->len)
diff --git a/drivers/scsi/scsi_netlink.c b/drivers/scsi/scsi_netlink.c
index 109802f776ed..50e624fb8307 100644
--- a/drivers/scsi/scsi_netlink.c
+++ b/drivers/scsi/scsi_netlink.c
@@ -111,7 +111,7 @@ scsi_nl_rcv_msg(struct sk_buff *skb)
next_msg:
if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
- netlink_ack(skb, nlh, err);
+ netlink_ack(skb, nlh, err, NULL);
skb_pull(skb, rlen);
}
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index da14ab61f363..47562e940e9c 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -62,11 +62,41 @@ netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
}
+/**
+ * struct netlink_ext_ack - netlink extended ACK report struct
+ * @_msg: message string to report - don't access directly, use
+ * %NL_SET_ERR_MSG
+ * @bad_attr: attribute with error
+ * @missing_attr: number of missing attr (or 0)
+ * @cookie: cookie data to return to userspace (for success)
+ * @cookie_len: actual cookie data length
+ */
+struct netlink_ext_ack {
+ const char *_msg;
+ const struct nlattr *bad_attr;
+ u16 missing_attr;
+ u8 cookie[NETLINK_MAX_COOKIE_LEN];
+ u8 cookie_len;
+};
+
+/* Always use this macro, this allows later putting the
+ * message into a separate section or such for things
+ * like translation or listing all possible messages.
+ * Currently string formatting is not supported (due
+ * to the lack of an output buffer.)
+ */
+#define NL_SET_ERR_MSG(extack, msg) do { \
+ static const char *_msg = (msg); \
+ \
+ (extack)->_msg = _msg; \
+} while (0)
+
extern void netlink_kernel_release(struct sock *sk);
extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
-extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
+extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
+ const struct netlink_ext_ack *extack);
extern int netlink_has_listeners(struct sock *sk, unsigned int group);
extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
diff --git a/include/net/netlink.h b/include/net/netlink.h
index b239fcd33d80..a064ec3e2ee1 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -233,7 +233,8 @@ struct nl_info {
};
int netlink_rcv_skb(struct sk_buff *skb,
- int (*cb)(struct sk_buff *, struct nlmsghdr *));
+ int (*cb)(struct sk_buff *, struct nlmsghdr *,
+ struct netlink_ext_ack *));
int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
unsigned int group, int report, gfp_t flags);
diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index f3946a27bd07..d1564557d645 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -101,6 +101,29 @@ struct nlmsghdr {
struct nlmsgerr {
int error;
struct nlmsghdr msg;
+ /*
+ * followed by the message contents unless NETLINK_CAP_ACK was set,
+ * message length is aligned with NLMSG_ALIGN()
+ */
+ /*
+ * followed by TLVs defined in enum nlmsgerr_attrs
+ * if NETLINK_EXT_ACK was set
+ */
+};
+
+/**
+ * enum nlmsgerr_attrs - netlink error message attributes
+ * @NLMSGERR_ATTR_UNUSED: unused
+ * @NLMSGERR_ATTR_MSG: error message string (string)
+ * @NLMSGERR_ATTR_OFFS: error offset in the original message (u32)
+ * @NLMSGERR_ATTR_ATTR: top-level attribute that caused the error
+ * (or is missing, u16)
+ */
+enum nlmsgerr_attrs {
+ NLMSGERR_ATTR_UNUSED,
+ NLMSGERR_ATTR_MSG,
+ NLMSGERR_ATTR_OFFS,
+ NLMSGERR_ATTR_ATTR,
};
#define NETLINK_ADD_MEMBERSHIP 1
@@ -115,6 +138,7 @@ struct nlmsgerr {
#define NETLINK_LISTEN_ALL_NSID 8
#define NETLINK_LIST_MEMBERSHIPS 9
#define NETLINK_CAP_ACK 10
+#define NETLINK_EXT_ACK 11
struct nl_pktinfo {
__u32 group;
diff --git a/kernel/audit.c b/kernel/audit.c
index 2f4964cfde0b..d54bf5932374 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1402,7 +1402,7 @@ static void audit_receive_skb(struct sk_buff *skb)
err = audit_receive_msg(skb, nlh);
/* if err or if this message says it wants a response */
if (err || (nlh->nlmsg_flags & NLM_F_ACK))
- netlink_ack(skb, nlh, err);
+ netlink_ack(skb, nlh, err, NULL);
nlh = nlmsg_next(nlh, &len);
}
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index b2bd4c9ee860..9788147241f4 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4120,7 +4120,8 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb)
/* Process one rtnetlink message. */
-static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
rtnl_doit_func doit;
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index fb9d0e2fd148..217f4e3b82f6 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -238,7 +238,8 @@ static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
return err;
}
-static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
int ret;
diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
index 1ab30e7d3f99..81dac16933fc 100644
--- a/net/hsr/hsr_netlink.c
+++ b/net/hsr/hsr_netlink.c
@@ -350,7 +350,7 @@ static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info)
return 0;
invalid:
- netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL);
+ netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
return 0;
nla_put_failure:
@@ -432,7 +432,7 @@ static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info)
return 0;
invalid:
- netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL);
+ netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
return 0;
nla_put_failure:
diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index c296f9b606d4..26356bf8cebf 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1305,7 +1305,7 @@ ip_set_dump_start(struct sk_buff *skb, struct netlink_callback *cb)
* manually :-(
*/
if (nlh->nlmsg_flags & NLM_F_ACK)
- netlink_ack(cb->skb, nlh, ret);
+ netlink_ack(cb->skb, nlh, ret, NULL);
return ret;
}
}
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 68eda920160e..181d3bb800e6 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -148,7 +148,8 @@ int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid,
EXPORT_SYMBOL_GPL(nfnetlink_unicast);
/* Process one complete nfnetlink message. */
-static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
const struct nfnl_callback *nc;
@@ -261,7 +262,7 @@ static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb)
struct nfnl_err *nfnl_err, *next;
list_for_each_entry_safe(nfnl_err, next, err_list, head) {
- netlink_ack(skb, nfnl_err->nlh, nfnl_err->err);
+ netlink_ack(skb, nfnl_err->nlh, nfnl_err->err, NULL);
nfnl_err_del(nfnl_err);
}
}
@@ -284,13 +285,13 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
int err;
if (subsys_id >= NFNL_SUBSYS_COUNT)
- return netlink_ack(skb, nlh, -EINVAL);
+ return netlink_ack(skb, nlh, -EINVAL, NULL);
replay:
status = 0;
skb = netlink_skb_clone(oskb, GFP_KERNEL);
if (!skb)
- return netlink_ack(oskb, nlh, -ENOMEM);
+ return netlink_ack(oskb, nlh, -ENOMEM, NULL);
nfnl_lock(subsys_id);
ss = nfnl_dereference_protected(subsys_id);
@@ -304,20 +305,20 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
#endif
{
nfnl_unlock(subsys_id);
- netlink_ack(oskb, nlh, -EOPNOTSUPP);
+ netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL);
return kfree_skb(skb);
}
}
if (!ss->commit || !ss->abort) {
nfnl_unlock(subsys_id);
- netlink_ack(oskb, nlh, -EOPNOTSUPP);
+ netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL);
return kfree_skb(skb);
}
if (genid && ss->valid_genid && !ss->valid_genid(net, genid)) {
nfnl_unlock(subsys_id);
- netlink_ack(oskb, nlh, -ERESTART);
+ netlink_ack(oskb, nlh, -ERESTART, NULL);
return kfree_skb(skb);
}
@@ -407,7 +408,8 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
* pointing to the batch header.
*/
nfnl_err_reset(&err_list);
- netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM);
+ netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM,
+ NULL);
status |= NFNL_BATCH_FAILURE;
goto done;
}
@@ -467,7 +469,7 @@ static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh)
err = nla_parse(cda, NFNL_BATCH_MAX, attr, attrlen, nfnl_batch_policy);
if (err < 0) {
- netlink_ack(skb, nlh, err);
+ netlink_ack(skb, nlh, err, NULL);
return;
}
if (cda[NFNL_BATCH_GENID])
@@ -493,7 +495,7 @@ static void nfnetlink_rcv(struct sk_buff *skb)
return;
if (!netlink_net_capable(skb, CAP_NET_ADMIN)) {
- netlink_ack(skb, nlh, -EPERM);
+ netlink_ack(skb, nlh, -EPERM, NULL);
return;
}
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index fc232441cf23..02cffb0a3904 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1652,6 +1652,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
nlk->flags &= ~NETLINK_F_CAP_ACK;
err = 0;
break;
+ case NETLINK_EXT_ACK:
+ if (val)
+ nlk->flags |= NETLINK_F_EXT_ACK;
+ else
+ nlk->flags &= ~NETLINK_F_EXT_ACK;
+ err = 0;
+ break;
default:
err = -ENOPROTOOPT;
}
@@ -1736,6 +1743,16 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
return -EFAULT;
err = 0;
break;
+ case NETLINK_EXT_ACK:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
default:
err = -ENOPROTOOPT;
}
@@ -2267,21 +2284,37 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
}
EXPORT_SYMBOL(__netlink_dump_start);
-void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
+void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
+ const struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
struct nlmsghdr *rep;
struct nlmsgerr *errmsg;
size_t payload = sizeof(*errmsg);
+ size_t acksize = sizeof(*errmsg);
struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
/* Error messages get the original request appened, unless the user
- * requests to cap the error message.
+ * requests to cap the error message, and get extra error data if
+ * requested.
*/
- if (!(nlk->flags & NETLINK_F_CAP_ACK) && err)
- payload += nlmsg_len(nlh);
+ if (err) {
+ if (!(nlk->flags & NETLINK_F_CAP_ACK))
+ payload += nlmsg_len(nlh);
+ acksize = payload;
+ if (nlk->flags & NETLINK_F_EXT_ACK) {
+ if (extack && extack->_msg)
+ acksize +=
+ nla_total_size(strlen(extack->_msg) + 1);
+ if (extack && extack->bad_attr)
+ acksize += nla_total_size(sizeof(u32));
+ if (extack &&
+ (extack->missing_attr || extack->bad_attr))
+ acksize += nla_total_size(sizeof(u16));
+ }
+ }
- skb = nlmsg_new(payload, GFP_KERNEL);
+ skb = nlmsg_new(acksize, GFP_KERNEL);
if (!skb) {
struct sock *sk;
@@ -2300,14 +2333,35 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
NLMSG_ERROR, payload, 0);
errmsg = nlmsg_data(rep);
errmsg->error = err;
- memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
+ memcpy(&errmsg->msg, nlh,
+ !(nlk->flags & NETLINK_F_CAP_ACK) ? nlh->nlmsg_len
+ : sizeof(*nlh));
+
+ if (err && nlk->flags & NETLINK_F_EXT_ACK) {
+ if (extack && extack->_msg)
+ WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
+ extack->_msg));
+ if (extack && extack->bad_attr &&
+ !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
+ (u8 *)extack->bad_attr >= in_skb->data +
+ in_skb->len))
+ WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
+ (u8 *)extack->bad_attr -
+ in_skb->data));
+ if (extack && extack->missing_attr)
+ WARN_ON(nla_put_u16(skb, NLMSGERR_ATTR_ATTR,
+ extack->missing_attr));
+ }
+
netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
}
EXPORT_SYMBOL(netlink_ack);
int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
- struct nlmsghdr *))
+ struct nlmsghdr *,
+ struct netlink_ext_ack *))
{
+ struct netlink_ext_ack extack = {};
struct nlmsghdr *nlh;
int err;
@@ -2328,13 +2382,13 @@ int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
goto ack;
- err = cb(skb, nlh);
+ err = cb(skb, nlh, &extack);
if (err == -EINTR)
goto skip;
ack:
if (nlh->nlmsg_flags & NLM_F_ACK || err)
- netlink_ack(skb, nlh, err);
+ netlink_ack(skb, nlh, err, &extack);
skip:
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index f792f8d7f982..3490f2430532 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h
@@ -13,6 +13,7 @@
#define NETLINK_F_RECV_NO_ENOBUFS 0x8
#define NETLINK_F_LISTEN_ALL_NSID 0x10
#define NETLINK_F_CAP_ACK 0x20
+#define NETLINK_F_EXT_ACK 0x40
#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 92e0981f7404..57b2e3648bc0 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -605,7 +605,8 @@ static int genl_family_rcv_msg(const struct genl_family *family,
return err;
}
-static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
const struct genl_family *family;
int err;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 40a8aa39220d..1ba8c115a993 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2448,7 +2448,8 @@ static const struct xfrm_link {
[XFRM_MSG_GETSPDINFO - XFRM_MSG_BASE] = { .doit = xfrm_get_spdinfo },
};
-static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct nlattr *attrs[XFRMA_MAX+1];
--
2.11.0
