Commit 9e1f7a31 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'tools-ynl-gen-support-sub-messages-and-rt-link' 

Jakub Kicinski says:

====================
tools: ynl-gen: support sub-messages and rt-link

Sub-messages are how we express "polymorphism" in YNL. Donald added
the support to specs and Python a while back, support them in C, too.
Sub-message is a nest, but the interpretation of the attribute types
within that nest depends on a value of another attribute. For example
in rt-link the "kind" attribute contains the link type (veth, bonding,
etc.) and based on that the right enum has to be applied to interpret
link-specific attributes.

The last message is probably the most interesting to look at, as it
adds a fairly advanced sample.

This patch only contains enough support for rtnetlink, we will need
a little more complexity to support TC, where sub-messages may contain
fixed headers, and where the selector may be in a different nest than
the submessage.
====================

Link: https://patch.msgid.link/20250515231650.1325372-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 622b91e0 d5d1813b

Documentation/netlink/specs/rt-link.yaml

+4 −0
Original line number Diff line number Diff line
@@ -594,6 +594,7 @@ definitions: 
        name: reasm-overlaps

  - name: br-boolopt-multi

    type: struct

    header: linux/if_bridge.h

    members:

      -

        name: optval
@@ -826,6 +827,8 @@ definitions: 
      - name: default

  -

    name: ovpn-mode

    enum-name: ovpn-mode

    name-prefix: ovpn-mode

    type: enum

    entries:

      - p2p
@@ -2195,6 +2198,7 @@ attribute-sets: 
        type: u16

  -

    name: linkinfo-ovpn-attrs

    name-prefix: ifla-ovpn-

    attributes:

      -

        name: mode

tools/net/ynl/Makefile.deps

+4 −0
Original line number Diff line number Diff line
@@ -33,5 +33,9 @@ CFLAGS_ovs_flow:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h) 
CFLAGS_ovs_vport:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)

CFLAGS_rt-addr:=$(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h) \

	$(call get_hdr_inc,__LINUX_IF_ADDR_H,if_addr.h)

CFLAGS_rt-link:=$(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h) \

	$(call get_hdr_inc,_LINUX_IF_LINK_H,if_link.h)

CFLAGS_rt-neigh:=$(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h)

CFLAGS_rt-route:=$(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h)

CFLAGS_rt-rule:=$(call get_hdr_inc,__LINUX_FIB_RULES_H,fib_rules.h)

CFLAGS_tcp_metrics:=$(call get_hdr_inc,_LINUX_TCP_METRICS_H,tcp_metrics.h)

tools/net/ynl/generated/Makefile

+3 −4
Original line number Diff line number Diff line
@@ -22,10 +22,9 @@ TOOL:=../pyynl/ynl_gen_c.py 
TOOL_RST:=../pyynl/ynl_gen_rst.py



SPECS_DIR:=../../../../Documentation/netlink/specs

GENS_PATHS=$(shell grep -nrI --files-without-match \

		'protocol: netlink' \

		$(SPECS_DIR))

GENS=$(patsubst $(SPECS_DIR)/%.yaml,%,${GENS_PATHS}) rt-addr rt-route

SPECS_PATHS=$(wildcard $(SPECS_DIR)/*.yaml)

GENS_UNSUP=conntrack nftables tc

GENS=$(filter-out ${GENS_UNSUP},$(patsubst $(SPECS_DIR)/%.yaml,%,${SPECS_PATHS}))

SRCS=$(patsubst %,%-user.c,${GENS})

HDRS=$(patsubst %,%-user.h,${GENS})

OBJS=$(patsubst %,%-user.o,${GENS})

tools/net/ynl/lib/ynl-priv.h

+7 −1
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ enum ynl_policy_type { 
	YNL_PT_UINT,

	YNL_PT_NUL_STR,

	YNL_PT_BITFIELD32,

	YNL_PT_SUBMSG,

};



enum ynl_parse_result {
@@ -42,7 +43,10 @@ typedef int (*ynl_parse_cb_t)(const struct nlmsghdr *nlh, 
			      struct ynl_parse_arg *yarg);



struct ynl_policy_attr {

	enum ynl_policy_type type;

	enum ynl_policy_type type:8;

	__u8 is_submsg:1;

	__u8 is_selector:1;

	__u16 selector_type;

	unsigned int len;

	const char *name;

	const struct ynl_policy_nest *nest;
@@ -103,6 +107,8 @@ struct nlmsghdr * 
ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);



int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr);

int ynl_submsg_failed(struct ynl_parse_arg *yarg, const char *field_name,

		      const char *sel_name);



/* YNL specific helpers used by the auto-generated code */

tools/net/ynl/lib/ynl.c

+84 −9
Original line number Diff line number Diff line
@@ -45,8 +45,39 @@ 
#define perr(_ys, _msg)			__yerr(&(_ys)->err, errno, _msg)



/* -- Netlink boiler plate */

static bool

ynl_err_walk_is_sel(const struct ynl_policy_nest *policy,

		    const struct nlattr *attr)

{

	unsigned int type = ynl_attr_type(attr);



	return policy && type <= policy->max_attr &&

		policy->table[type].is_selector;

}



static const struct ynl_policy_nest *

ynl_err_walk_sel_policy(const struct ynl_policy_attr *policy_attr,

			const struct nlattr *selector)

{

	const struct ynl_policy_nest *policy = policy_attr->nest;

	const char *sel;

	unsigned int i;



	if (!policy_attr->is_submsg)

		return policy;



	sel = ynl_attr_get_str(selector);

	for (i = 0; i <= policy->max_attr; i++) {

		if (!strcmp(sel, policy->table[i].name))

			return policy->table[i].nest;

	}



	return NULL;

}



static int

ynl_err_walk_report_one(const struct ynl_policy_nest *policy, unsigned int type,

ynl_err_walk_report_one(const struct ynl_policy_nest *policy,

			const struct nlattr *selector, unsigned int type,

			char *str, int str_sz, int *n)

{

	if (!policy) {
@@ -67,9 +98,34 @@ ynl_err_walk_report_one(const struct ynl_policy_nest *policy, unsigned int type, 
		return 1;

	}



	if (*n < str_sz)

		*n += snprintf(str, str_sz - *n,

	if (*n < str_sz) {

		int sz;



		sz = snprintf(str, str_sz - *n,

			      ".%s", policy->table[type].name);

		*n += sz;

		str += sz;

	}



	if (policy->table[type].is_submsg) {

		if (!selector) {

			if (*n < str_sz)

				*n += snprintf(str, str_sz, "(!selector)");

			return 1;

		}



		if (ynl_attr_type(selector) !=

		    policy->table[type].selector_type) {

			if (*n < str_sz)

				*n += snprintf(str, str_sz, "(!=selector)");

			return 1;

		}



		if (*n < str_sz)

			*n += snprintf(str, str_sz - *n, "(%s)",

				       ynl_attr_get_str(selector));

	}



	return 0;

}
@@ -78,6 +134,8 @@ ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, 
	     const struct ynl_policy_nest *policy, char *str, int str_sz,

	     const struct ynl_policy_nest **nest_pol)

{

	const struct ynl_policy_nest *next_pol;

	const struct nlattr *selector = NULL;

	unsigned int astart_off, aend_off;

	const struct nlattr *attr;

	unsigned int data_len;
@@ -96,6 +154,10 @@ ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, 
	ynl_attr_for_each_payload(start, data_len, attr) {

		astart_off = (char *)attr - (char *)start;

		aend_off = (char *)ynl_attr_data_end(attr) - (char *)start;



		if (ynl_err_walk_is_sel(policy, attr))

			selector = attr;



		if (aend_off <= off)

			continue;
@@ -109,16 +171,20 @@ ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, 


	type = ynl_attr_type(attr);



	if (ynl_err_walk_report_one(policy, type, str, str_sz, &n))

	if (ynl_err_walk_report_one(policy, selector, type, str, str_sz, &n))

		return n;



	next_pol = ynl_err_walk_sel_policy(&policy->table[type], selector);

	if (!next_pol)

		return n;



	if (!off) {

		if (nest_pol)

			*nest_pol = policy->table[type].nest;

			*nest_pol = next_pol;

		return n;

	}



	if (!policy->table[type].nest) {

	if (!next_pol) {

		if (n < str_sz)

			n += snprintf(str, str_sz, "!nest");

		return n;
@@ -128,7 +194,7 @@ ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, 
	start =  ynl_attr_data(attr);

	end = start + ynl_attr_data_len(attr);



	return n + ynl_err_walk(ys, start, end, off, policy->table[type].nest,

	return n + ynl_err_walk(ys, start, end, off, next_pol,

				&str[n], str_sz - n, nest_pol);

}
@@ -231,7 +297,7 @@ ynl_ext_ack_check(struct ynl_sock *ys, const struct nlmsghdr *nlh, 
		}



		n2 = 0;

		ynl_err_walk_report_one(nest_pol, type, &miss_attr[n],

		ynl_err_walk_report_one(nest_pol, NULL, type, &miss_attr[n],

					sizeof(miss_attr) - n, &n2);

		n += n2;
@@ -384,6 +450,15 @@ int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr) 
	return 0;

}



int ynl_submsg_failed(struct ynl_parse_arg *yarg, const char *field_name,

		      const char *sel_name)

{

	yerr(yarg->ys, YNL_ERROR_SUBMSG_KEY,

	     "Parsing error: Sub-message key not set (msg %s, key %s)",

	     field_name, sel_name);

	return YNL_PARSE_CB_ERROR;

}



/* Generic code */



static void ynl_err_reset(struct ynl_sock *ys)