Subject: Re: [patch iproute2 v7 2/2] tc: Add batchsize feature for filter and actions

From: Marcelo Ricardo Leitner <[email-masked]>
Date: Tue, 9 Jan 2018 17:13:54 -0200

On Tue, Jan 09, 2018 at 03:59:08PM +0900, Chris Mi wrote:
> 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 <[email-masked]>
> ---
>  tc/m_action.c  |  60 +++++++++++++++++----------
>  tc/tc.c        | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
>  tc/tc_common.h |   5 ++-
>  tc/tc_filter.c |  97 +++++++++++++++++++++++++------------------
>  4 files changed, 210 insertions(+), 79 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)
>  {
> -	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;
> +
> +	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;
> +
> +	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,
> -						&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,
> -					       &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..f32e4978 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");
>  }
>  
> -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 +217,39 @@ static int do_cmd(int argc, char **argv)
>  	return -1;
>  }
>  
> +static bool batchsize_enabled(int argc, char *argv[])
> +{
> +	if (argc < 2)
> +		return false;
> +	if ((strcmp(argv[0], "filter") && strcmp(argv[0], "action"))
> +	    || (strcmp(argv[1], "add") && strcmp(argv[1], "delete")
> +	    && strcmp(argv[1], "change") && strcmp(argv[1], "replace")))
> +		return false;
> +
> +	return true;
> +}
> +
> +struct batch_buf {
> +	struct batch_buf	*next;
> +	char			buf[16420];	/* sizeof (struct nlmsghdr) +
> +						   sizeof (struct tcmsg) +
> +						   MAX_MSG */
> +};
> +
>  static int batch(const char *name)
>  {
> -	char *line = NULL;
> +	struct batch_buf *head = NULL, *tail = NULL, *buf;

Hi. Overall it looks much better IMHO.

Maybe declare *buf in the two sections that it is used, to make it
clear that it cannot be reused between them? (minor, yes..)

> +	char *largv[100], *largv_next[100];

A define for the 100 is probably welcomed,

> +	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;
> +	int ret = 0, i;
> +	bool send;
>  
>  	batch_mode = 1;
>  	if (name && strcmp(name, "-") != 0) {
> @@ -240,23 +268,92 @@ 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);
> +		if (bs_enabled) {
> +			buf = calloc(1, sizeof (struct batch_buf));

if (!buf) .. ?

> +			if (head == NULL) {
> +				head = tail = buf;
> +				buf->next = NULL;

this

> +			} else {
> +				buf->next = NULL;

and this NULL assignments are not needed because you used calloc(), so
it's already zeroed.

> +				tail->next = buf;
> +				tail = buf;
> +			}
> +			++batchsize;
> +		}
> +
> +		/*
> +		 * In batch mode, if we haven't accumulated enough commands
> +		 * and this is not the last command and this command & next
> +		 * command both support the batchsize feature, don't send the
> +		 * 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);
> +		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;
> +		for (i = 0; i < largc; i ++)
> +			largv[i] = largv_next[i];

This loop can be a single memcpy()
  memcpy(largv, largv_next, sizeof(largv));

> +
> +		if (send && bs_enabled_saved) {
> +			struct iovec *iov, *iovs;
> +			struct nlmsghdr *n;
> +			iov = iovs = malloc(batchsize * sizeof (struct iovec));
> +			for (buf = head; buf != NULL; buf = buf->next, ++iov) {
> +				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,
> +					cmdlineno - (batchsize + ret) - 1);
> +				return 2;
> +			}
> +			for (buf = head; buf != NULL; buf = head) {
> +				head = buf->next;
> +				free(buf);

Maybe we could reuse these buffers? Put them in another list when free
and pull from it when allocating. And allocate a new one if the
recycle pool is empty. But maybe glibc already does some work for
that.

That's all my comments in this patchset. Thanks Chris.

> +			}
> +			head = tail = NULL;
> +			batchsize = 0;
> +			free(iovs);
> +		}
> +	} while (!lastline);
> +
> +Exit:
> +	free(line);
>  
>  	rtnl_close(&rth);
>  	return ret;
> @@ -341,7 +438,7 @@ 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");
>  }
>  
> -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;
> +
> +	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)
>  				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");
>  				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");
>  				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");
>  				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)
>  		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)
>  	}
>  
>  	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));
>  
> -	if (rtnl_talk(&rth, &req.n, NULL) < 0) {
> -		fprintf(stderr, "We have an error talking to the kernel\n");
> +	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,
> -					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);
>  	if (matches(*argv, "replace") == 0)
>  		return tc_filter_modify(RTM_NEWTFILTER, NLM_F_CREATE, argc-1,
> -					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);
>  	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
> -- 
> 2.14.3
>