linux/tools/net/ynl/lib/ynl.h
Jakub Kicinski 15d2540e0d tools: ynl: check for overflow of constructed messages
Donald points out that we don't check for overflows.
Stash the length of the message on nlmsg_pid (nlmsg_seq would
do as well). This allows the attribute helpers to remain
self-contained (no extra arguments). Also let the put
helpers continue to return nothing. The error is checked
only in (newly introduced) ynl_msg_end().

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240305185000.964773-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-07 11:01:31 -08:00

114 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
#ifndef __YNL_C_H
#define __YNL_C_H 1
#include <stddef.h>
#include <linux/genetlink.h>
#include <linux/types.h>
#include "ynl-priv.h"
enum ynl_error_code {
YNL_ERROR_NONE = 0,
__YNL_ERRNO_END = 4096,
YNL_ERROR_INTERNAL,
YNL_ERROR_DUMP_INTER,
YNL_ERROR_EXPECT_ACK,
YNL_ERROR_EXPECT_MSG,
YNL_ERROR_UNEXPECT_MSG,
YNL_ERROR_ATTR_MISSING,
YNL_ERROR_ATTR_INVALID,
YNL_ERROR_UNKNOWN_NTF,
YNL_ERROR_INV_RESP,
YNL_ERROR_INPUT_INVALID,
YNL_ERROR_INPUT_TOO_BIG,
};
/**
* struct ynl_error - error encountered by YNL
* @code: errno (low values) or YNL error code (enum ynl_error_code)
* @attr_offs: offset of bad attribute (for very advanced users)
* @msg: error message
*
* Error information for when YNL operations fail.
* Users should interact with the err member of struct ynl_sock directly.
* The main exception to that rule is ynl_sock_create().
*/
struct ynl_error {
enum ynl_error_code code;
unsigned int attr_offs;
char msg[512];
};
/**
* struct ynl_family - YNL family info
* Family description generated by codegen. Pass to ynl_sock_create().
*/
struct ynl_family {
/* private: */
const char *name;
size_t hdr_len;
const struct ynl_ntf_info *ntf_info;
unsigned int ntf_info_size;
};
/**
* struct ynl_sock - YNL wrapped netlink socket
* @err: YNL error descriptor, cleared on every request.
*/
struct ynl_sock {
struct ynl_error err;
/* private: */
const struct ynl_family *family;
int socket;
__u32 seq;
__u32 portid;
__u16 family_id;
unsigned int n_mcast_groups;
struct {
unsigned int id;
char name[GENL_NAMSIZ];
} *mcast_groups;
struct ynl_ntf_base_type *ntf_first;
struct ynl_ntf_base_type **ntf_last_next;
struct nlmsghdr *nlh;
struct ynl_policy_nest *req_policy;
unsigned char *tx_buf;
unsigned char *rx_buf;
unsigned char raw_buf[];
};
struct ynl_sock *
ynl_sock_create(const struct ynl_family *yf, struct ynl_error *e);
void ynl_sock_destroy(struct ynl_sock *ys);
#define ynl_dump_foreach(dump, iter) \
for (typeof(dump->obj) *iter = &dump->obj; \
!ynl_dump_obj_is_last(iter); \
iter = ynl_dump_obj_next(iter))
int ynl_subscribe(struct ynl_sock *ys, const char *grp_name);
int ynl_socket_get_fd(struct ynl_sock *ys);
int ynl_ntf_check(struct ynl_sock *ys);
/**
* ynl_has_ntf() - check if socket has *parsed* notifications
* @ys: active YNL socket
*
* Note that this does not take into account notifications sitting
* in netlink socket, just the notifications which have already been
* read and parsed (e.g. during a ynl_ntf_check() call).
*/
static inline bool ynl_has_ntf(struct ynl_sock *ys)
{
return ys->ntf_last_next != &ys->ntf_first;
}
struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys);
void ynl_ntf_free(struct ynl_ntf_base_type *ntf);
#endif