This patch adds extack support for generic cls handling. The extack
will be set deeper to each called function which is not part of netdev
core api.

Cc: David Ahern <dsah...@gmail.com>
Signed-off-by: Alexander Aring <ar...@mojatatu.com>
---
 net/sched/cls_api.c | 56 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 44 insertions(+), 12 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index e500d11da9cd..0a3e2a2f8917 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -122,7 +122,8 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 }
 
 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
-                                         u32 prio, struct tcf_chain *chain)
+                                         u32 prio, struct tcf_chain *chain,
+                                         struct netlink_ext_ack *extack)
 {
        struct tcf_proto *tp;
        int err;
@@ -148,6 +149,7 @@ static struct tcf_proto *tcf_proto_create(const char *kind, 
u32 protocol,
                        module_put(tp->ops->owner);
                        err = -EAGAIN;
                } else {
+                       NL_SET_ERR_MSG(extack, "TC classifier not found");
                        err = -ENOENT;
                }
                goto errout;
@@ -935,7 +937,8 @@ static int tfilter_notify(struct net *net, struct sk_buff 
*oskb,
 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
                              struct nlmsghdr *n, struct tcf_proto *tp,
                              struct tcf_block *block, struct Qdisc *q,
-                             u32 parent, void *fh, bool unicast, bool *last)
+                             u32 parent, void *fh, bool unicast, bool *last,
+                             struct netlink_ext_ack *extack)
 {
        struct sk_buff *skb;
        u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -947,6 +950,7 @@ static int tfilter_del_notify(struct net *net, struct 
sk_buff *oskb,
 
        if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
                          n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
+               NL_SET_ERR_MSG(extack, "Failed to build del event 
notification");
                kfree_skb(skb);
                return -EINVAL;
        }
@@ -960,8 +964,11 @@ static int tfilter_del_notify(struct net *net, struct 
sk_buff *oskb,
        if (unicast)
                return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 
-       return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
-                             n->nlmsg_flags & NLM_F_ECHO);
+       err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
+                            n->nlmsg_flags & NLM_F_ECHO);
+       if (err < 0)
+               NL_SET_ERR_MSG(extack, "Failed to send filter delete 
notification");
+       return err;
 }
 
 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
@@ -1021,8 +1028,10 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
        if (prio == 0) {
                switch (n->nlmsg_type) {
                case RTM_DELTFILTER:
-                       if (protocol || t->tcm_handle || tca[TCA_KIND])
+                       if (protocol || t->tcm_handle || tca[TCA_KIND]) {
+                               NL_SET_ERR_MSG(extack, "Cannot flush filters 
with protocol, handle or kind set");
                                return -ENOENT;
+                       }
                        break;
                case RTM_NEWTFILTER:
                        /* If no priority is provided by the user,
@@ -1035,6 +1044,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
                        }
                        /* fall-through */
                default:
+                       NL_SET_ERR_MSG(extack, "Invalid filter command with 
priority of zero");
                        return -ENOENT;
                }
        }
@@ -1063,23 +1073,31 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
                        parent = q->handle;
                } else {
                        q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
-                       if (!q)
+                       if (!q) {
+                               NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't 
exists");
                                return -EINVAL;
+                       }
                }
 
                /* Is it classful? */
                cops = q->ops->cl_ops;
-               if (!cops)
+               if (!cops) {
+                       NL_SET_ERR_MSG(extack, "Qdisc not classful");
                        return -EINVAL;
+               }
 
-               if (!cops->tcf_block)
+               if (!cops->tcf_block) {
+                       NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
                        return -EOPNOTSUPP;
+               }
 
                /* Do we search for filter, attached to class? */
                if (TC_H_MIN(parent)) {
                        cl = cops->find(q, parent);
-                       if (cl == 0)
+                       if (cl == 0) {
+                               NL_SET_ERR_MSG(extack, "Specified class doesn't 
exist");
                                return -ENOENT;
+                       }
                }
 
                /* And the last stroke */
@@ -1097,12 +1115,14 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
 
        chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
        if (chain_index > TC_ACT_EXT_VAL_MASK) {
+               NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper 
limit");
                err = -EINVAL;
                goto errout;
        }
        chain = tcf_chain_get(block, chain_index,
                              n->nlmsg_type == RTM_NEWTFILTER);
        if (!chain) {
+               NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
                err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
                goto errout;
        }
@@ -1118,6 +1138,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
        tp = tcf_chain_tp_find(chain, &chain_info, protocol,
                               prio, prio_allocate);
        if (IS_ERR(tp)) {
+               NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol 
not found");
                err = PTR_ERR(tp);
                goto errout;
        }
@@ -1126,12 +1147,14 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
                /* Proto-tcf does not exist, create new one */
 
                if (tca[TCA_KIND] == NULL || !protocol) {
+                       NL_SET_ERR_MSG(extack, "Filter kind and protocol must 
be specified");
                        err = -EINVAL;
                        goto errout;
                }
 
                if (n->nlmsg_type != RTM_NEWTFILTER ||
                    !(n->nlmsg_flags & NLM_F_CREATE)) {
+                       NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and 
NLM_F_CREATE to create a new filter");
                        err = -ENOENT;
                        goto errout;
                }
@@ -1140,13 +1163,14 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
                        prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 
                tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
-                                     protocol, prio, chain);
+                                     protocol, prio, chain, extack);
                if (IS_ERR(tp)) {
                        err = PTR_ERR(tp);
                        goto errout;
                }
                tp_created = 1;
        } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
+               NL_SET_ERR_MSG(extack, "Specified filter kind does not match 
existing one");
                err = -EINVAL;
                goto errout;
        }
@@ -1165,6 +1189,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
 
                if (n->nlmsg_type != RTM_NEWTFILTER ||
                    !(n->nlmsg_flags & NLM_F_CREATE)) {
+                       NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and 
NLM_F_CREATE to create a new filter");
                        err = -ENOENT;
                        goto errout;
                }
@@ -1176,13 +1201,15 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
                        if (n->nlmsg_flags & NLM_F_EXCL) {
                                if (tp_created)
                                        tcf_proto_destroy(tp);
+                               NL_SET_ERR_MSG(extack, "Filter already exists");
                                err = -EEXIST;
                                goto errout;
                        }
                        break;
                case RTM_DELTFILTER:
                        err = tfilter_del_notify(net, skb, n, tp, block,
-                                                q, parent, fh, false, &last);
+                                                q, parent, fh, false, &last,
+                                                extack);
                        if (err)
                                goto errout;
                        if (last) {
@@ -1193,8 +1220,11 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct 
nlmsghdr *n,
                case RTM_GETTFILTER:
                        err = tfilter_notify(net, skb, n, tp, block, q, parent,
                                             fh, RTM_NEWTFILTER, true);
+                       if (err < 0)
+                               NL_SET_ERR_MSG(extack, "Failed to send filter 
notify message");
                        goto errout;
                default:
+                       NL_SET_ERR_MSG(extack, "Invalid netlink message type");
                        err = -EINVAL;
                        goto errout;
                }
@@ -1418,8 +1448,10 @@ int tcf_exts_validate(struct net *net, struct tcf_proto 
*tp, struct nlattr **tb,
        }
 #else
        if ((exts->action && tb[exts->action]) ||
-           (exts->police && tb[exts->police]))
+           (exts->police && tb[exts->police])) {
+               NL_SET_ERR_MSG(extack, "Classifier actions are not supported 
per compile options (CONFIG_NET_CLS_ACT)");
                return -EOPNOTSUPP;
+       }
 #endif
 
        return 0;
-- 
2.11.0

Reply via email to