[PATCH v2 iproute2 1/2] utils: make hex2mem available to all users

[PATCH v2 iproute2 1/2] utils: make hex2mem available to all users

[Jamal Hadi Salim]

From: Jamal Hadi Salim <jhs@mojatatu.com>

hex2mem() api is useful for parsing hexstrings which are then packed in
a stream of chars.

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---
 include/utils.h |  1 +
 ip/ipl2tp.c     | 25 -------------------------
 lib/utils.c     | 25 +++++++++++++++++++++++++
 3 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/include/utils.h b/include/utils.h
index dc1d6b9..22369e0 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -118,6 +118,7 @@ int get_be32(__be32 *val, const char *arg, int base);
 int get_be16(__be16 *val, const char *arg, int base);
 int get_addr64(__u64 *ap, const char *cp);
 
+int hex2mem(const char *buf, uint8_t *mem, int count);
 char *hexstring_n2a(const __u8 *str, int len, char *buf, int blen);
 __u8 *hexstring_a2n(const char *str, __u8 *buf, int blen, unsigned int *len);
 #define ADDR64_BUF_SIZE sizeof("xxxx:xxxx:xxxx:xxxx")
diff --git a/ip/ipl2tp.c b/ip/ipl2tp.c
index 0f91aeb..88664c9 100644
--- a/ip/ipl2tp.c
+++ b/ip/ipl2tp.c
@@ -485,31 +485,6 @@ static int get_tunnel(struct l2tp_data *p)
  * Command parser
  *****************************************************************************/
 
-static int hex2mem(const char *buf, uint8_t *mem, int count)
-{
-	int i, j;
-	int c;
-
-	for (i = 0, j = 0; i < count; i++, j += 2) {
-		c = get_hex(buf[j]);
-		if (c < 0)
-			goto err;
-
-		mem[i] = c << 4;
-
-		c = get_hex(buf[j + 1]);
-		if (c < 0)
-			goto err;
-
-		mem[i] |= c;
-	}
-
-	return 0;
-
-err:
-	return -1;
-}
-
 static void usage(void) __attribute__((noreturn));
 
 static void usage(void)
diff --git a/lib/utils.c b/lib/utils.c
index 83c9d09..870c4f1 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -962,6 +962,31 @@ __u8 *hexstring_a2n(const char *str, __u8 *buf, int blen, unsigned int *len)
 	return buf;
 }
 
+int hex2mem(const char *buf, uint8_t *mem, int count)
+{
+	int i, j;
+	int c;
+
+	for (i = 0, j = 0; i < count; i++, j += 2) {
+		c = get_hex(buf[j]);
+		if (c < 0)
+			goto err;
+
+		mem[i] = c << 4;
+
+		c = get_hex(buf[j + 1]);
+		if (c < 0)
+			goto err;
+
+		mem[i] |= c;
+	}
+
+	return 0;
+
+err:
+	return -1;
+}
+
 int addr64_n2a(__u64 addr, char *buff, size_t len)
 {
 	__u16 *words = (__u16 *)&addr;
-- 
1.9.1

[PATCH v2 iproute2 2/2] actions: Add support for user cookies

[Jamal Hadi Salim]

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 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/tc/m_action.c b/tc/m_action.c
index bb19df8..00bc219 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");
 	}
 
-- 
1.9.1

Re: [PATCH v2 iproute2 2/2] actions: Add support for user cookies

[Stephen Hemminger]

On Fri, 10 Feb 2017 06:25:44 -0500
Jamal Hadi Salim <jhs@mojatatu.com> wrote:

> 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.

The support for this has not been accepted upstream in net-next yet.
Therefore submitting it into iproute2 is premature.
Pleas resubmit when the kernel part (and uapi) are upstream.

Re: [PATCH v2 iproute2 1/2] utils: make hex2mem available to all users

[Stephen Hemminger]

On Fri, 10 Feb 2017 06:25:43 -0500
Jamal Hadi Salim <jhs@mojatatu.com> wrote:

> From: Jamal Hadi Salim <jhs@mojatatu.com>
> 
> hex2mem() api is useful for parsing hexstrings which are then packed in
> a stream of chars.
> 
> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>

I went ahead and applied this part since it makes sense to have it now.
The other part depends on TC_ACT_COOKIE which is not upstream in net-next yet.