Commit 17b3ce29 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

tools: ynl: support creating non-genl sockets 



Classic netlink has static family IDs specified in YAML,
there is no family name -> ID lookup. Support providing
the ID info to the library via the generated struct and
make library use it. Since NETLINK_ROUTE is ID 0 we need
an extra boolean to indicate classic_id is to be used.

Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Reviewed-by: default avatarDonald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250410014658.782120-8-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1652e1f3

tools/net/ynl/lib/ynl.c

+34 −17
Original line number Diff line number Diff line
@@ -663,6 +663,7 @@ ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse) 
	struct sockaddr_nl addr;

	struct ynl_sock *ys;

	socklen_t addrlen;

	int sock_type;

	int one = 1;



	ys = malloc(sizeof(*ys) + 2 * YNL_SOCKET_BUFFER_SIZE);
@@ -675,7 +676,9 @@ ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse) 
	ys->rx_buf = &ys->raw_buf[YNL_SOCKET_BUFFER_SIZE];

	ys->ntf_last_next = &ys->ntf_first;



	ys->socket = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);

	sock_type = yf->is_classic ? yf->classic_id : NETLINK_GENERIC;



	ys->socket = socket(AF_NETLINK, SOCK_RAW, sock_type);

	if (ys->socket < 0) {

		__perr(yse, "failed to create a netlink socket");

		goto err_free_sock;
@@ -708,8 +711,9 @@ ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse) 
	ys->portid = addr.nl_pid;

	ys->seq = random();





	if (ynl_sock_read_family(ys, yf->name)) {

	if (yf->is_classic) {

		ys->family_id = yf->classic_id;

	} else if (ynl_sock_read_family(ys, yf->name)) {

		if (yse)

			memcpy(yse, &ys->err, sizeof(*yse));

		goto err_close_sock;
@@ -791,13 +795,21 @@ static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh) 
	struct ynl_parse_arg yarg = { .ys = ys, };

	const struct ynl_ntf_info *info;

	struct ynl_ntf_base_type *rsp;

	struct genlmsghdr *gehdr;

	__u32 cmd;

	int ret;



	if (ys->family->is_classic) {

		cmd = nlh->nlmsg_type;

	} else {

		struct genlmsghdr *gehdr;



		gehdr = ynl_nlmsg_data(nlh);

	if (gehdr->cmd >= ys->family->ntf_info_size)

		cmd = gehdr->cmd;

	}



	if (cmd >= ys->family->ntf_info_size)

		return YNL_PARSE_CB_ERROR;

	info = &ys->family->ntf_info[gehdr->cmd];

	info = &ys->family->ntf_info[cmd];

	if (!info->cb)

		return YNL_PARSE_CB_ERROR;
@@ -811,7 +823,7 @@ static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh) 
		goto err_free;



	rsp->family = nlh->nlmsg_type;

	rsp->cmd = gehdr->cmd;

	rsp->cmd = cmd;



	*ys->ntf_last_next = rsp;

	ys->ntf_last_next = &rsp->next;
@@ -863,6 +875,10 @@ int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg) 
static int

ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd)

{

	if (ys->family->is_classic) {

		if (nlh->nlmsg_type != rsp_cmd)

			return ynl_ntf_parse(ys, nlh);

	} else {

		struct genlmsghdr *gehdr;



		if (ynl_nlmsg_data_len(nlh) < sizeof(*gehdr)) {
@@ -874,6 +890,7 @@ ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd) 
		gehdr = ynl_nlmsg_data(nlh);

		if (gehdr->cmd != rsp_cmd)

			return ynl_ntf_parse(ys, nlh);

	}



	return 0;

}

tools/net/ynl/lib/ynl.h

+3 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#ifndef __YNL_C_H

#define __YNL_C_H 1



#include <stdbool.h>

#include <stddef.h>

#include <linux/genetlink.h>

#include <linux/types.h>
@@ -48,6 +49,8 @@ struct ynl_family { 
/* private: */

	const char *name;

	size_t hdr_len;

	bool is_classic;

	__u16 classic_id;

	const struct ynl_ntf_info *ntf_info;

	unsigned int ntf_info_size;

};

tools/net/ynl/pyynl/ynl_gen_c.py

+6 −3
Original line number Diff line number Diff line
@@ -971,9 +971,6 @@ class Family(SpecFamily): 
    def resolve(self):

        self.resolve_up(super())



        if self.yaml.get('protocol', 'genetlink') not in {'genetlink', 'genetlink-c', 'genetlink-legacy'}:

            raise Exception("Codegen only supported for genetlink")



        self.c_name = c_lower(self.ident_name)

        if 'name-prefix' in self.yaml['operations']:

            self.op_prefix = c_upper(self.yaml['operations']['name-prefix'])
@@ -1020,6 +1017,9 @@ class Family(SpecFamily): 
    def new_operation(self, elem, req_value, rsp_value):

        return Operation(self, elem, req_value, rsp_value)



    def is_classic(self):

        return self.proto == 'netlink-raw'



    def _mark_notify(self):

        for op in self.msgs.values():

            if 'notify' in op:
@@ -2730,6 +2730,9 @@ def render_user_family(family, cw, prototype): 


    cw.block_start(f'{symbol} = ')

    cw.p(f'.name\t\t= "{family.c_name}",')

    if family.is_classic():

        cw.p(f'.is_classic\t= true,')

        cw.p(f'.classic_id\t= {family.get("protonum")},')

    if family.fixed_header:

        cw.p(f'.hdr_len\t= sizeof(struct genlmsghdr) + sizeof(struct {c_lower(family.fixed_header)}),')

    else: