[PATCH v2 net-next] net:sched: add action inheritdsfield to skbedit
From: Fu, Qiaobin <hidden>
Date: 2018-05-28 05:40:20
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
The new action inheritdsfield copies the field DS of IPv4 and IPv6 packets into skb->priority. This enables later classification of packets based on the DS field. Original idea by Jamal Hadi Salim [off-list ref] Signed-off-by: Qiaobin Fu <redacted> Reviewed-by: Michel Machado <redacted> --- Note that the motivation for this patch is found in the following discussion: https://www.spinics.net/lists/netdev/msg501061.html ---
diff --git a/include/uapi/linux/tc_act/tc_skbedit.h b/include/uapi/linux/tc_act/tc_skbedit.h
index fbcfe27..432ad2f 100644
--- a/include/uapi/linux/tc_act/tc_skbedit.h
+++ b/include/uapi/linux/tc_act/tc_skbedit.h@@ -30,9 +30,11 @@ #define SKBEDIT_F_MARK 0x4 #define SKBEDIT_F_PTYPE 0x8 #define SKBEDIT_F_MASK 0x10 +#define SKBEDIT_F_INHERITDSFIELD 0x20 struct tc_skbedit { tc_gen; + __u64 flags; }; enum {
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index 6138d1d7..c3e9d03 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c@@ -23,6 +23,9 @@ #include <linux/rtnetlink.h> #include <net/netlink.h> #include <net/pkt_sched.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <net/dsfield.h> #include <linux/tc_act/tc_skbedit.h> #include <net/tc_act/tc_skbedit.h>
@@ -39,8 +42,32 @@ static int tcf_skbedit(struct sk_buff *skb, const struct tc_action *a, tcf_lastuse_update(&d->tcf_tm); bstats_update(&d->tcf_bstats, skb); - if (d->flags & SKBEDIT_F_PRIORITY) - skb->priority = d->priority; + if (d->flags & SKBEDIT_F_INHERITDSFIELD) { + int wlen = skb_network_offset(skb); + + switch (tc_skb_protocol(skb)) { + case htons(ETH_P_IP): + wlen += sizeof(struct iphdr); + if (!pskb_may_pull(skb, wlen)) + goto err; + skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2; + break; + + case htons(ETH_P_IPV6): + wlen += sizeof(struct ipv6hdr); + if (!pskb_may_pull(skb, wlen)) + goto err; + skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2; + break; + + default: + goto default_priority; + } + } else { +default_priority: + if (d->flags & SKBEDIT_F_PRIORITY) + skb->priority = d->priority; + } if (d->flags & SKBEDIT_F_QUEUE_MAPPING && skb->dev->real_num_tx_queues > d->queue_mapping) skb_set_queue_mapping(skb, d->queue_mapping);
@@ -53,6 +80,10 @@ static int tcf_skbedit(struct sk_buff *skb, const struct tc_action *a, spin_unlock(&d->tcf_lock); return d->tcf_action; + +err: + spin_unlock(&d->tcf_lock); + return TC_ACT_SHOT; } static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
@@ -115,6 +146,8 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla, } parm = nla_data(tb[TCA_SKBEDIT_PARMS]); + if (parm->flags & SKBEDIT_F_INHERITDSFIELD) + flags |= SKBEDIT_F_INHERITDSFIELD; exists = tcf_idr_check(tn, parm->index, a, bind); if (exists && bind)