Commit 853a14ba authored by Amir Vadai's avatar Amir Vadai Committed by David S. Miller

net/act_pedit: Introduce 'add' operation

This command could be useful to inc/dec fields.

For example, to forward any TCP packet and decrease its TTL:
$ tc filter add dev enp0s9 protocol ip parent ffff: \
    flower ip_proto tcp \
    action pedit munge ip ttl add 0xff pipe \
    action mirred egress redirect dev veth0

In the example above, adding 0xff to this u8 field is actually
decreasing it by one, since the operation is masked.
Signed-off-by: default avatarAmir Vadai <amir@vadai.me>
Reviewed-by: default avatarOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 71d0ed70
...@@ -5,6 +5,7 @@ ...@@ -5,6 +5,7 @@
struct tcf_pedit_key_ex { struct tcf_pedit_key_ex {
enum pedit_header_type htype; enum pedit_header_type htype;
enum pedit_cmd cmd;
}; };
struct tcf_pedit { struct tcf_pedit {
......
...@@ -20,6 +20,7 @@ enum { ...@@ -20,6 +20,7 @@ enum {
enum { enum {
TCA_PEDIT_KEY_EX_HTYPE = 1, TCA_PEDIT_KEY_EX_HTYPE = 1,
TCA_PEDIT_KEY_EX_CMD = 2,
__TCA_PEDIT_KEY_EX_MAX __TCA_PEDIT_KEY_EX_MAX
}; };
#define TCA_PEDIT_KEY_EX_MAX (__TCA_PEDIT_KEY_EX_MAX - 1) #define TCA_PEDIT_KEY_EX_MAX (__TCA_PEDIT_KEY_EX_MAX - 1)
...@@ -38,6 +39,13 @@ enum pedit_header_type { ...@@ -38,6 +39,13 @@ enum pedit_header_type {
}; };
#define TCA_PEDIT_HDR_TYPE_MAX (__PEDIT_HDR_TYPE_MAX - 1) #define TCA_PEDIT_HDR_TYPE_MAX (__PEDIT_HDR_TYPE_MAX - 1)
enum pedit_cmd {
TCA_PEDIT_KEY_EX_CMD_SET = 0,
TCA_PEDIT_KEY_EX_CMD_ADD = 1,
__PEDIT_CMD_MAX,
};
#define TCA_PEDIT_CMD_MAX (__PEDIT_CMD_MAX - 1)
struct tc_pedit_key { struct tc_pedit_key {
__u32 mask; /* AND */ __u32 mask; /* AND */
__u32 val; /*XOR */ __u32 val; /*XOR */
......
...@@ -36,6 +36,7 @@ static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = { ...@@ -36,6 +36,7 @@ static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = { static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
[TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 }, [TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 },
[TCA_PEDIT_KEY_EX_CMD] = { .type = NLA_U16 },
}; };
static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla, static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla,
...@@ -75,14 +76,17 @@ static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla, ...@@ -75,14 +76,17 @@ static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla,
if (err) if (err)
goto err_out; goto err_out;
if (!tb[TCA_PEDIT_KEY_EX_HTYPE]) { if (!tb[TCA_PEDIT_KEY_EX_HTYPE] ||
!tb[TCA_PEDIT_KEY_EX_CMD]) {
err = -EINVAL; err = -EINVAL;
goto err_out; goto err_out;
} }
k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]); k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);
if (k->htype > TCA_PEDIT_HDR_TYPE_MAX) { if (k->htype > TCA_PEDIT_HDR_TYPE_MAX ||
k->cmd > TCA_PEDIT_CMD_MAX) {
err = -EINVAL; err = -EINVAL;
goto err_out; goto err_out;
} }
...@@ -110,7 +114,8 @@ static int tcf_pedit_key_ex_dump(struct sk_buff *skb, ...@@ -110,7 +114,8 @@ static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
key_start = nla_nest_start(skb, TCA_PEDIT_KEY_EX); key_start = nla_nest_start(skb, TCA_PEDIT_KEY_EX);
if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype)) { if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) ||
nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd)) {
nlmsg_trim(skb, keys_start); nlmsg_trim(skb, keys_start);
return -EINVAL; return -EINVAL;
} }
...@@ -280,15 +285,19 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, ...@@ -280,15 +285,19 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
struct tc_pedit_key *tkey = p->tcfp_keys; struct tc_pedit_key *tkey = p->tcfp_keys;
struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex;
enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
u32 *ptr, _data; u32 *ptr, _data;
int offset = tkey->off; int offset = tkey->off;
int hoffset; int hoffset;
u32 val;
int rc; int rc;
if (tkey_ex) { if (tkey_ex) {
htype = tkey_ex->htype; htype = tkey_ex->htype;
cmd = tkey_ex->cmd;
tkey_ex++; tkey_ex++;
} }
...@@ -330,7 +339,20 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a, ...@@ -330,7 +339,20 @@ static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
if (!ptr) if (!ptr)
goto bad; goto bad;
/* just do it, baby */ /* just do it, baby */
*ptr = ((*ptr & tkey->mask) ^ tkey->val); switch (cmd) {
case TCA_PEDIT_KEY_EX_CMD_SET:
val = tkey->val;
break;
case TCA_PEDIT_KEY_EX_CMD_ADD:
val = (*ptr + tkey->val) & ~tkey->mask;
break;
default:
pr_info("tc filter pedit bad command (%d)\n",
cmd);
goto bad;
}
*ptr = ((*ptr & tkey->mask) ^ val);
if (ptr == &_data) if (ptr == &_data)
skb_store_bits(skb, hoffset + offset, ptr, 4); skb_store_bits(skb, hoffset + offset, ptr, 4);
} }
......
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