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[iproute2,1/1] actions: Add support for user cookies

Message ID 1490128502-22133-1-git-send-email-jhs@emojatatu.com
State Superseded, archived
Delegated to: stephen hemminger
Headers show

Commit Message

Jamal Hadi Salim March 21, 2017, 8:35 p.m. UTC 
From: Jamal Hadi Salim <jhs@mojatatu.com>

Make use of 128b user cookies

Introduce optional 128-bit action cookie.
Like all other cookie schemes in the networking world (eg in protocols
like http or existing kernel fib protocol field, etc) the idea is to
save user state that when retrieved serves as a correlator. The kernel
_should not_ intepret it. The user can store whatever they wish in the
128 bits.

Sample exercise(showing variable length use of cookie)

.. create an accept action with cookie a1b2c3d4
sudo $TC actions add action ok index 1 cookie a1b2c3d4

.. dump all gact actions..
sudo $TC -s actions ls action gact

    action order 0: gact action pass
     random type none pass val 0
     index 1 ref 1 bind 0 installed 5 sec used 5 sec
    Action statistics:
    Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
    backlog 0b 0p requeues 0
    cookie a1b2c3d4

.. bind the accept action to a filter..
sudo $TC filter add dev lo parent ffff: protocol ip prio 1 \
u32 match ip dst 127.0.0.1/32 flowid 1:1 action gact index 1

... send some traffic..
$ ping 127.0.0.1 -c 3
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.020 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms
64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.038 ms

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---
 tc/m_action.c | 44 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 6 deletions(-)

Comments

Stephen Hemminger March 21, 2017, 9:22 p.m. UTC | #1 
Minor style issues.

> +			if (*argv && strcmp(*argv, "cookie") == 0) {
> +				int slen;
slen is strlen() and that returns size_t not int.

> +
> +				NEXT_ARG();
> +				slen = strlen(*argv);
> +				if (slen > (TC_COOKIE_MAX_SIZE*2))

No extra (), and space around *

> +					invarg("cookie cannot exceed %d\n",
> +					       *argv);
> +
> +				if (hex2mem(*argv, act_ck, slen/2) < 0)
Space around / operator

> +					invarg("cookie must be a hex string\n",
> +					       *argv);
> +
> +				act_ck_len = slen;
> +				argc--;
> +				argv++;
> +			}
> +
> +			if (act_ck_len)
> +				addattr_l(n, MAX_MSG, TCA_ACT_COOKIE,
> +					  (const void *)&act_ck, act_ck_len);

Cast to void *  is not necessary.
diff mbox

Patch

diff --git a/tc/m_action.c b/tc/m_action.c
index 05ef07e..9d5857c 100644
--- a/tc/m_action.c
+++ b/tc/m_action.c
@@ -150,18 +150,19 @@  new_cmd(char **argv)
 
 }
 
-int
-parse_action(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
+int parse_action(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
 {
 	int argc = *argc_p;
 	char **argv = *argv_p;
 	struct rtattr *tail, *tail2;
 	char k[16];
+	int act_ck_len = 0;
 	int ok = 0;
 	int eap = 0; /* expect action parameters */
 
 	int ret = 0;
 	int prio = 0;
+	unsigned char act_ck[TC_COOKIE_MAX_SIZE];
 
 	if (argc <= 0)
 		return -1;
@@ -215,16 +216,39 @@  done0:
 			addattr_l(n, MAX_MSG, ++prio, NULL, 0);
 			addattr_l(n, MAX_MSG, TCA_ACT_KIND, k, strlen(k) + 1);
 
-			ret = a->parse_aopt(a, &argc, &argv, TCA_ACT_OPTIONS, n);
+			ret = a->parse_aopt(a, &argc, &argv, TCA_ACT_OPTIONS,
+					    n);
 
 			if (ret < 0) {
 				fprintf(stderr, "bad action parsing\n");
 				goto bad_val;
 			}
+
+			if (*argv && strcmp(*argv, "cookie") == 0) {
+				int slen;
+
+				NEXT_ARG();
+				slen = strlen(*argv);
+				if (slen > (TC_COOKIE_MAX_SIZE*2))
+					invarg("cookie cannot exceed %d\n",
+					       *argv);
+
+				if (hex2mem(*argv, act_ck, slen/2) < 0)
+					invarg("cookie must be a hex string\n",
+					       *argv);
+
+				act_ck_len = slen;
+				argc--;
+				argv++;
+			}
+
+			if (act_ck_len)
+				addattr_l(n, MAX_MSG, TCA_ACT_COOKIE,
+					  (const void *)&act_ck, act_ck_len);
+
 			tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 			ok++;
 		}
-
 	}
 
 	if (eap > 0) {
@@ -245,8 +269,7 @@  bad_val:
 	return -1;
 }
 
-static int
-tc_print_one_action(FILE *f, struct rtattr *arg)
+static int tc_print_one_action(FILE *f, struct rtattr *arg)
 {
 
 	struct rtattr *tb[TCA_ACT_MAX + 1];
@@ -274,8 +297,17 @@  tc_print_one_action(FILE *f, struct rtattr *arg)
 		return err;
 
 	if (show_stats && tb[TCA_ACT_STATS]) {
+
 		fprintf(f, "\tAction statistics:\n");
 		print_tcstats2_attr(f, tb[TCA_ACT_STATS], "\t", NULL);
+		if (tb[TCA_ACT_COOKIE]) {
+			int strsz = RTA_PAYLOAD(tb[TCA_ACT_COOKIE]);
+			char b1[strsz+1];
+
+			fprintf(f, "\n\tcookie len %d %s ", strsz,
+				hexstring_n2a(RTA_DATA(tb[TCA_ACT_COOKIE]),
+					      strsz, b1, sizeof(b1)));
+		}
 		fprintf(f, "\n");
 	}