RE: [patch iproute2 v8 2/2] tc: Add batchsize feature for filter and actions

-----Original Message-----
From: David Ahern [mailto:dsahern@gmail.com]
Sent: Thursday, January 11, 2018 3:41 AM
To: Chris Mi <redacted>; netdev@vger.kernel.org
Cc: gerlitz.or@gmail.com; stephen@networkplumber.org;
marcelo.leitner@gmail.com; phil@nwl.cc
Subject: Re: [patch iproute2 v8 2/2] tc: Add batchsize feature for filter and
actions

On 1/9/18 8:27 PM, Chris Mi wrote:

quoted

Currently in tc batch mode, only one command is read from the batch
file and sent to kernel to process. With this support, at most 128
commands can be accumulated before sending to kernel.

Now it only works for the following successive commands:
filter and actions add/delete/change/replace.

Signed-off-by: Chris Mi <redacted>
---
 tc/m_action.c  |  60 +++++++++++++--------
 tc/tc.c        | 165

++++++++++++++++++++++++++++++++++++++++++++++++++++-----

quoted

 tc/tc_common.h |   5 +-
 tc/tc_filter.c |  97 +++++++++++++++++++--------------
 4 files changed, 249 insertions(+), 78 deletions(-)

diff --git a/tc/m_action.c b/tc/m_action.c index fc422364..e5c53a80

100644

--- a/tc/m_action.c
+++ b/tc/m_action.c

@@ -546,40 +546,56 @@ bad_val:
 	return ret;
 }

+struct tc_action_req {
+	struct nlmsghdr		n;
+	struct tcamsg		t;
+	char			buf[MAX_MSG];
+};
+
 static int tc_action_modify(int cmd, unsigned int flags,
-			    int *argc_p, char ***argv_p)
+			    int *argc_p, char ***argv_p,
+			    void *buf)

you really need a buflen; you should not make assumptions about the length
of buffer passed to these functions.

Done.

quoted

 {
-	int argc = *argc_p;
+	struct tc_action_req *req, action_req;
 	char **argv = *argv_p;
+	struct rtattr *tail;
+	int argc = *argc_p;
+	struct iovec iov;
 	int ret = 0;
-	struct {
-		struct nlmsghdr         n;
-		struct tcamsg           t;
-		char                    buf[MAX_MSG];
-	} req = {
-		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcamsg)),
-		.n.nlmsg_flags = NLM_F_REQUEST | flags,
-		.n.nlmsg_type = cmd,
-		.t.tca_family = AF_UNSPEC,
-	};
-	struct rtattr *tail = NLMSG_TAIL(&req.n);
+
+	if (buf)
+		req = buf;
+	else
+		req = &action_req;
+

And a memset is needed for the !buf path since action_req is not initialized.

Done.

quoted

+	req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcamsg));
+	req->n.nlmsg_flags = NLM_F_REQUEST | flags;
+	req->n.nlmsg_type = cmd;
+	req->t.tca_family = AF_UNSPEC;
+	tail = NLMSG_TAIL(&req->n);

 	argc -= 1;
 	argv += 1;
-	if (parse_action(&argc, &argv, TCA_ACT_TAB, &req.n)) {
+	if (parse_action(&argc, &argv, TCA_ACT_TAB, &req->n)) {
 		fprintf(stderr, "Illegal \"action\"\n");
 		return -1;
 	}
-	tail->rta_len = (void *) NLMSG_TAIL(&req.n) - (void *) tail;
+	tail->rta_len = (void *) NLMSG_TAIL(&req->n) - (void *) tail;
+
+	*argc_p = argc;
+	*argv_p = argv;

-	if (rtnl_talk(&rth, &req.n, NULL) < 0) {
+	iov.iov_base = &req->n;
+	iov.iov_len = req->n.nlmsg_len;

you can leave that as rtnl_talk; no need to change the !buf case to
rtnl_talk_iov.

Done.

quoted

+
+	if (buf)
+		return 0;
+
+	if (rtnl_talk_iov(&rth, &iov, 1, NULL) < 0) {
 		fprintf(stderr, "We have an error talking to the kernel\n");
 		ret = -1;
 	}

-	*argc_p = argc;
-	*argv_p = argv;
-
 	return ret;
 }

@@ -679,7 +695,7 @@ bad_val:
 	return ret;
 }

-int do_action(int argc, char **argv)
+int do_action(int argc, char **argv, void *buf)
 {

 	int ret = 0;

@@ -689,12 +705,12 @@ int do_action(int argc, char **argv)
 		if (matches(*argv, "add") == 0) {
 			ret =  tc_action_modify(RTM_NEWACTION,
 						NLM_F_EXCL |

NLM_F_CREATE,

quoted

-						&argc, &argv);
+						&argc, &argv, buf);
 		} else if (matches(*argv, "change") == 0 ||
 			  matches(*argv, "replace") == 0) {
 			ret = tc_action_modify(RTM_NEWACTION,
 					       NLM_F_CREATE |

NLM_F_REPLACE,

quoted

-					       &argc, &argv);
+					       &argc, &argv, buf);
 		} else if (matches(*argv, "delete") == 0) {
 			argc -= 1;
 			argv += 1;

diff --git a/tc/tc.c b/tc/tc.c
index ad9f07e9..44277405 100644
--- a/tc/tc.c
+++ b/tc/tc.c

@@ -193,16 +193,16 @@ static void usage(void)
 			"                    -nm | -nam[es] | { -cf | -conf } path } | -

j[son]\n");

quoted

 }

-static int do_cmd(int argc, char **argv)
+static int do_cmd(int argc, char **argv, void *buf)
 {
 	if (matches(*argv, "qdisc") == 0)
 		return do_qdisc(argc-1, argv+1);
 	if (matches(*argv, "class") == 0)
 		return do_class(argc-1, argv+1);
 	if (matches(*argv, "filter") == 0)
-		return do_filter(argc-1, argv+1);
+		return do_filter(argc-1, argv+1, buf);
 	if (matches(*argv, "actions") == 0)
-		return do_action(argc-1, argv+1);
+		return do_action(argc-1, argv+1, buf);
 	if (matches(*argv, "monitor") == 0)
 		return do_tcmonitor(argc-1, argv+1);
 	if (matches(*argv, "exec") == 0)

@@ -217,11 +217,79 @@ static int do_cmd(int argc, char **argv)
 	return -1;
 }

+static bool batchsize_enabled(int argc, char *argv[]) {
+	if (argc < 2)
+		return false;
+	if ((matches(argv[0], "filter") && matches(argv[0], "actions"))
+	    || (matches(argv[1], "add") && matches(argv[1], "delete")
+	    && matches(argv[1], "change") && matches(argv[1], "replace")))
+		return false;

That is really hard to follow. It would be better to default the response to
false and test for the expected set:
    if argv[0] is filter or actions &&
       argv[1] is add or delete or change or replace
        return true;

    return false;

I just realize that 'action delete' is not supported because function tc_action_gd() is called
for 'delete' instead of tc_action_modify().  So there is a good reason to use table now.

Done.

quoted

+	return true;
+}
+
+struct batch_buf {
+	struct batch_buf	*next;
+	char			buf[16420];	/* sizeof (struct nlmsghdr) +
+						   sizeof (struct tcmsg) +

actions has a different ancillary header -- tcamsg. Use the buflen approach is
more robust.

Done. Actually 16420  = sizeof (struct nlmsghdr) + max(sizeof (struct tcmsg) + sizeof (struct tcamsg)) + MAX_MSG */

quoted

+						   MAX_MSG */
+};
+
+static struct batch_buf *get_batch_buf(struct batch_buf **pool) {
+	struct batch_buf *buf;
+
+	if (*pool == NULL)
+		buf = calloc(1, sizeof (struct batch_buf));
+	else {
+		buf = *pool;
+		*pool = (*pool)->next;
+		memset(buf, 0, sizeof (struct batch_buf));
+	}
+	return buf;
+}
+
+static void put_batch_bufs(struct batch_buf **pool,
+			   struct batch_buf **head, struct batch_buf **tail) {
+	if (*head == NULL || *tail == NULL)
+		return;
+
+	if (*pool == NULL)
+		*pool = *head;
+	else {
+		(*tail)->next = *pool;
+		*pool = *head;
+	}
+	*head = NULL;
+	*tail = NULL;
+}
+
+static void free_batch_bufs(struct batch_buf **pool) {
+	struct batch_buf *buf;
+
+	for (buf = *pool; buf != NULL; buf = *pool) {
+		*pool = buf->next;
+		free(buf);
+	}
+	*pool = NULL;
+}
+
 static int batch(const char *name)
 {
-	char *line = NULL;
+	struct batch_buf *head = NULL, *tail = NULL, *buf_pool = NULL;
+	char *largv[100], *largv_next[100];
+	char *line, *line_next = NULL;
+	bool bs_enabled_next = false;
+	bool bs_enabled = false;
+	bool lastline = false;
+	int largc, largc_next;
+	bool bs_enabled_saved;
+	int batchsize = 0;
 	size_t len = 0;
 	int ret = 0;
+	bool send;

 	batch_mode = 1;
 	if (name && strcmp(name, "-") != 0) { @@ -240,25 +308,94 @@ static
int batch(const char *name)
 	}

 	cmdlineno = 0;
-	while (getcmdline(&line, &len, stdin) != -1) {
-		char *largv[100];
-		int largc;
+	if (getcmdline(&line, &len, stdin) == -1)
+		goto Exit;
+	largc = makeargs(line, largv, 100);
+	bs_enabled = batchsize_enabled(largc, largv);
+	bs_enabled_saved = bs_enabled;
+	do {
+		if (getcmdline(&line_next, &len, stdin) == -1)
+			lastline = true;
+
+		largc_next = makeargs(line_next, largv_next, 100);
+		bs_enabled_next = batchsize_enabled(largc_next,

largv_next);

quoted

+		if (bs_enabled) {
+			struct batch_buf *buf;

space between variables and code.

Done.

quoted

+			buf = get_batch_buf(&buf_pool);
+			if (!buf) {
+				fprintf(stderr, "failed to allocate

batch_buf\n");

quoted

+				return -1;
+			}
+			if (head == NULL)
+				head = tail = buf;
+			else {
+				tail->next = buf;
+				tail = buf;
+			}
+			++batchsize;
+		}
+
+		/*
+		 * In batch mode, if we haven't accumulated enough

commands

quoted

+		 * and this is not the last command and this command & next
+		 * command both support the batchsize feature, don't send

the

quoted

+		 * message immediately.
+		 */
+		if (!lastline && bs_enabled && bs_enabled_next
+		    && batchsize != MSG_IOV_MAX)
+			send = false;
+		else
+			send = true;
+
+		line = line_next;
+		line_next = NULL;
+		len = 0;
+		bs_enabled_saved = bs_enabled;
+		bs_enabled = bs_enabled_next;
+		bs_enabled_next = false;

-		largc = makeargs(line, largv, 100);
 		if (largc == 0)
 			continue;	/* blank line */

-		if (do_cmd(largc, largv)) {
-			fprintf(stderr, "Command failed %s:%d\n", name,

cmdlineno);

quoted

+		ret = do_cmd(largc, largv, tail == NULL ? NULL : tail->buf);
+		if (ret != 0) {
+			fprintf(stderr, "Command failed %s:%d\n", name,
+				cmdlineno - 1);
 			ret = 1;
 			if (!force)
 				break;
 		}
-	}
-	if (line)
-		free(line);
+		largc = largc_next;
+		memcpy(largv, largv_next, largc * sizeof(char *));
+
+		if (send && bs_enabled_saved) {
+			struct iovec *iov, *iovs;
+			struct batch_buf *buf;
+			struct nlmsghdr *n;
+			iov = iovs = malloc(batchsize * sizeof (struct iovec));
+			for (buf = head; buf != NULL; buf = buf->next, ++iov)

{

quoted

+				n = (struct nlmsghdr *)&buf->buf;
+				iov->iov_base = n;
+				iov->iov_len = n->nlmsg_len;
+			}
+
+			ret = rtnl_talk_iov(&rth, iovs, batchsize, NULL);
+			if (ret < 0) {
+				fprintf(stderr, "Command failed %s:%d\n",

name,

quoted

+					cmdlineno - (batchsize + ret) - 1);
+				return 2;
+			}
+			put_batch_bufs(&buf_pool, &head, &tail);
+			batchsize = 0;
+			free(iovs);
+		}
+	} while (!lastline);

+	free_batch_bufs(&buf_pool);
+Exit:
+	free(line);
 	rtnl_close(&rth);
+
 	return ret;
 }

@@ -341,7 +478,7 @@ int main(int argc, char **argv)
 		goto Exit;
 	}

-	ret = do_cmd(argc-1, argv+1);
+	ret = do_cmd(argc-1, argv+1, NULL);
 Exit:
 	rtnl_close(&rth);

diff --git a/tc/tc_common.h b/tc/tc_common.h index 264fbdac..59018da5

100644

--- a/tc/tc_common.h
+++ b/tc/tc_common.h

@@ -1,13 +1,14 @@
 /* SPDX-License-Identifier: GPL-2.0 */

 #define TCA_BUF_MAX	(64*1024)
+#define MSG_IOV_MAX	128

 extern struct rtnl_handle rth;

 extern int do_qdisc(int argc, char **argv);  extern int do_class(int

argc, char **argv); -extern int do_filter(int argc, char **argv);
-extern int do_action(int argc, char **argv);
+extern int do_filter(int argc, char **argv, void *buf); extern int
+do_action(int argc, char **argv, void *buf);
 extern int do_tcmonitor(int argc, char **argv);  extern int
do_exec(int argc, char **argv);

diff --git a/tc/tc_filter.c b/tc/tc_filter.c index 545cc3a1..7db4964b

100644

--- a/tc/tc_filter.c
+++ b/tc/tc_filter.c

@@ -42,28 +42,38 @@ static void usage(void)
 		"OPTIONS := ... try tc filter add <desired FILTER_KIND>

help\n");

quoted

}

-static int tc_filter_modify(int cmd, unsigned int flags, int argc,
char **argv)
+struct tc_filter_req {
+	struct nlmsghdr		n;
+	struct tcmsg		t;
+	char			buf[MAX_MSG];
+};
+
+static int tc_filter_modify(int cmd, unsigned int flags, int argc, char **argv,
+			    void *buf)
 {
-	struct {
-		struct nlmsghdr	n;
-		struct tcmsg		t;
-		char			buf[MAX_MSG];
-	} req = {
-		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
-		.n.nlmsg_flags = NLM_F_REQUEST | flags,
-		.n.nlmsg_type = cmd,
-		.t.tcm_family = AF_UNSPEC,
-	};
+	struct tc_filter_req *req, filter_req;
 	struct filter_util *q = NULL;
-	__u32 prio = 0;
-	__u32 protocol = 0;
-	int protocol_set = 0;
-	__u32 chain_index;
+	struct tc_estimator est = {};
+	char k[FILTER_NAMESZ] = {};
 	int chain_index_set = 0;
+	char d[IFNAMSIZ] = {};
+	int protocol_set = 0;
 	char *fhandle = NULL;
-	char  d[IFNAMSIZ] = {};
-	char  k[FILTER_NAMESZ] = {};
-	struct tc_estimator est = {};
+	__u32 protocol = 0;
+	__u32 chain_index;
+	struct iovec iov;
+	__u32 prio = 0;
+	int ret;
+
+	if (buf)
+		req = buf;
+	else
+		req = &filter_req;

same comment here about buflen and filter_req initialization.

Done.

quoted

+
+	req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
+	req->n.nlmsg_flags = NLM_F_REQUEST | flags;
+	req->n.nlmsg_type = cmd;
+	req->t.tcm_family = AF_UNSPEC;

 	if (cmd == RTM_NEWTFILTER && flags & NLM_F_CREATE)
 		protocol = htons(ETH_P_ALL);

@@ -75,37 +85,37 @@ static int tc_filter_modify(int cmd, unsigned int flags,

int argc, char **argv)

quoted

 				duparg("dev", *argv);
 			strncpy(d, *argv, sizeof(d)-1);
 		} else if (strcmp(*argv, "root") == 0) {
-			if (req.t.tcm_parent) {
+			if (req->t.tcm_parent) {
 				fprintf(stderr,
 					"Error: \"root\" is duplicate parent

ID\n");

quoted

 				return -1;
 			}
-			req.t.tcm_parent = TC_H_ROOT;
+			req->t.tcm_parent = TC_H_ROOT;
 		} else if (strcmp(*argv, "ingress") == 0) {
-			if (req.t.tcm_parent) {
+			if (req->t.tcm_parent) {
 				fprintf(stderr,
 					"Error: \"ingress\" is duplicate parent

ID\n");

quoted

 				return -1;
 			}
-			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
+			req->t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
 						     TC_H_MIN_INGRESS);
 		} else if (strcmp(*argv, "egress") == 0) {
-			if (req.t.tcm_parent) {
+			if (req->t.tcm_parent) {
 				fprintf(stderr,
 					"Error: \"egress\" is duplicate parent

ID\n");

quoted

 				return -1;
 			}
-			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
+			req->t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
 						     TC_H_MIN_EGRESS);
 		} else if (strcmp(*argv, "parent") == 0) {
 			__u32 handle;

 			NEXT_ARG();
-			if (req.t.tcm_parent)
+			if (req->t.tcm_parent)
 				duparg("parent", *argv);
 			if (get_tc_classid(&handle, *argv))
 				invarg("Invalid parent ID", *argv);
-			req.t.tcm_parent = handle;
+			req->t.tcm_parent = handle;
 		} else if (strcmp(*argv, "handle") == 0) {
 			NEXT_ARG();
 			if (fhandle)

@@ -152,26 +162,26 @@ static int tc_filter_modify(int cmd, unsigned int

flags, int argc, char **argv)

quoted

 		argc--; argv++;
 	}

-	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);
+	req->t.tcm_info = TC_H_MAKE(prio<<16, protocol);

 	if (chain_index_set)
-		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);
+		addattr32(&req->n, sizeof(*req), TCA_CHAIN, chain_index);

 	if (k[0])
-		addattr_l(&req.n, sizeof(req), TCA_KIND, k, strlen(k)+1);
+		addattr_l(&req->n, sizeof(*req), TCA_KIND, k, strlen(k)+1);

 	if (d[0])  {
 		ll_init_map(&rth);

-		req.t.tcm_ifindex = ll_name_to_index(d);
-		if (req.t.tcm_ifindex == 0) {
+		req->t.tcm_ifindex = ll_name_to_index(d);
+		if (req->t.tcm_ifindex == 0) {
 			fprintf(stderr, "Cannot find device \"%s\"\n", d);
 			return 1;
 		}
 	}

 	if (q) {
-		if (q->parse_fopt(q, fhandle, argc, argv, &req.n))
+		if (q->parse_fopt(q, fhandle, argc, argv, &req->n))
 			return 1;
 	} else {
 		if (fhandle) {

@@ -190,10 +200,17 @@ static int tc_filter_modify(int cmd, unsigned int

flags, int argc, char **argv)

quoted

 	}

 	if (est.ewma_log)
-		addattr_l(&req.n, sizeof(req), TCA_RATE, &est, sizeof(est));
+		addattr_l(&req->n, sizeof(*req), TCA_RATE, &est,

sizeof(est));

quoted

-	if (rtnl_talk(&rth, &req.n, NULL) < 0) {
-		fprintf(stderr, "We have an error talking to the kernel\n");

And here, no need to change to iov for the !buf case.

Done.

quoted

+	iov.iov_base = &req->n;
+	iov.iov_len = req->n.nlmsg_len;
+
+	if (buf)
+		return 0;
+
+	ret = rtnl_talk_iov(&rth, &iov, 1, NULL);
+	if (ret < 0) {
+		fprintf(stderr, "We have an error talking to the kernel, %d\n",
+ret);
 		return 2;
 	}

@@ -636,20 +653,20 @@ static int tc_filter_list(int argc, char **argv)
 	return 0;
 }

-int do_filter(int argc, char **argv)
+int do_filter(int argc, char **argv, void *buf)
 {
 	if (argc < 1)
 		return tc_filter_list(0, NULL);
 	if (matches(*argv, "add") == 0)
 		return tc_filter_modify(RTM_NEWTFILTER,

NLM_F_EXCL|NLM_F_CREATE,

quoted

-					argc-1, argv+1);
+					argc-1, argv+1, buf);
 	if (matches(*argv, "change") == 0)
-		return tc_filter_modify(RTM_NEWTFILTER, 0, argc-1, argv+1);
+		return tc_filter_modify(RTM_NEWTFILTER, 0, argc-1, argv+1,

buf);

quoted

 	if (matches(*argv, "replace") == 0)
 		return tc_filter_modify(RTM_NEWTFILTER, NLM_F_CREATE,

argc-1,

quoted

-					argv+1);
+					argv+1, buf);
 	if (matches(*argv, "delete") == 0)
-		return tc_filter_modify(RTM_DELTFILTER, 0,  argc-1, argv+1);
+		return tc_filter_modify(RTM_DELTFILTER, 0, argc-1, argv+1,

buf);

quoted

 	if (matches(*argv, "get") == 0)
 		return tc_filter_get(RTM_GETTFILTER, 0,  argc-1, argv+1);
 	if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0