tools/net/ynl/lib/ynl.h

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 #ifndef __YNL_C_H
   3 #define __YNL_C_H 1
   4
   5 #include <stddef.h>
   6 #include <linux/genetlink.h>
   7 #include <linux/types.h>
   8
   9 #include "ynl-priv.h"
  10
  11 enum ynl_error_code {
  12         YNL_ERROR_NONE = 0,
  13         __YNL_ERRNO_END = 4096,
  14         YNL_ERROR_INTERNAL,
  15         YNL_ERROR_DUMP_INTER,
  16         YNL_ERROR_EXPECT_ACK,
  17         YNL_ERROR_EXPECT_MSG,
  18         YNL_ERROR_UNEXPECT_MSG,
  19         YNL_ERROR_ATTR_MISSING,
  20         YNL_ERROR_ATTR_INVALID,
  21         YNL_ERROR_UNKNOWN_NTF,
  22         YNL_ERROR_INV_RESP,
  23         YNL_ERROR_INPUT_INVALID,
  24         YNL_ERROR_INPUT_TOO_BIG,
  25 };
  26
  27 /**
  28  * struct ynl_error - error encountered by YNL
  29  * @code:       errno (low values) or YNL error code (enum ynl_error_code)
  30  * @attr_offs:  offset of bad attribute (for very advanced users)
  31  * @msg:        error message
  32  *
  33  * Error information for when YNL operations fail.
  34  * Users should interact with the err member of struct ynl_sock directly.
  35  * The main exception to that rule is ynl_sock_create().
  36  */
  37 struct ynl_error {
  38         enum ynl_error_code code;
  39         unsigned int attr_offs;
  40         char msg[512];
  41 };
  42
  43 /**
  44  * struct ynl_family - YNL family info
  45  * Family description generated by codegen. Pass to ynl_sock_create().
  46  */
  47 struct ynl_family {
  48 /* private: */
  49         const char *name;
  50         size_t hdr_len;
  51         const struct ynl_ntf_info *ntf_info;
  52         unsigned int ntf_info_size;
  53 };
  54
  55 /**
  56  * struct ynl_sock - YNL wrapped netlink socket
  57  * @err: YNL error descriptor, cleared on every request.
  58  */
  59 struct ynl_sock {
  60         struct ynl_error err;
  61
  62 /* private: */
  63         const struct ynl_family *family;
  64         int socket;
  65         __u32 seq;
  66         __u32 portid;
  67         __u16 family_id;
  68
  69         unsigned int n_mcast_groups;
  70         struct {
  71                 unsigned int id;
  72                 char name[GENL_NAMSIZ];
  73         } *mcast_groups;
  74
  75         struct ynl_ntf_base_type *ntf_first;
  76         struct ynl_ntf_base_type **ntf_last_next;
  77
  78         struct nlmsghdr *nlh;
  79         const struct ynl_policy_nest *req_policy;
  80         unsigned char *tx_buf;
  81         unsigned char *rx_buf;
  82         unsigned char raw_buf[];
  83 };
  84
  85 struct ynl_sock *
  86 ynl_sock_create(const struct ynl_family *yf, struct ynl_error *e);
  87 void ynl_sock_destroy(struct ynl_sock *ys);
  88
  89 #define ynl_dump_foreach(dump, iter)                                    \
  90         for (typeof(dump->obj) *iter = &dump->obj;                      \
  91              !ynl_dump_obj_is_last(iter);                               \
  92              iter = ynl_dump_obj_next(iter))
  93
  94 /**
  95  * ynl_dump_empty() - does the dump have no entries
  96  * @dump: pointer to the dump list, as returned by a dump call
  97  *
  98  * Check if the dump is empty, i.e. contains no objects.
  99  * Dump calls return NULL on error, and terminator element if empty.
 100  */
 101 static inline bool ynl_dump_empty(void *dump)
 102 {
 103         return dump == (void *)YNL_LIST_END;
 104 }
 105
 106 int ynl_subscribe(struct ynl_sock *ys, const char *grp_name);
 107 int ynl_socket_get_fd(struct ynl_sock *ys);
 108 int ynl_ntf_check(struct ynl_sock *ys);
 109
 110 /**
 111  * ynl_has_ntf() - check if socket has *parsed* notifications
 112  * @ys: active YNL socket
 113  *
 114  * Note that this does not take into account notifications sitting
 115  * in netlink socket, just the notifications which have already been
 116  * read and parsed (e.g. during a ynl_ntf_check() call).
 117  */
 118 static inline bool ynl_has_ntf(struct ynl_sock *ys)
 119 {
 120         return ys->ntf_last_next != &ys->ntf_first;
 121 }
 122 struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys);
 123
 124 void ynl_ntf_free(struct ynl_ntf_base_type *ntf);
 125 #endif