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 <libmnl/libmnl.h> 7#include <linux/genetlink.h> 8#include <linux/types.h> 9 10struct mnl_socket; 11struct nlmsghdr; 12 13/* 14 * User facing code 15 */ 16 17struct ynl_ntf_base_type; 18struct ynl_ntf_info; 19struct ynl_sock; 20 21enum ynl_error_code { 22 YNL_ERROR_NONE = 0, 23 __YNL_ERRNO_END = 4096, 24 YNL_ERROR_INTERNAL, 25 YNL_ERROR_EXPECT_ACK, 26 YNL_ERROR_EXPECT_MSG, 27 YNL_ERROR_UNEXPECT_MSG, 28 YNL_ERROR_ATTR_MISSING, 29 YNL_ERROR_ATTR_INVALID, 30 YNL_ERROR_UNKNOWN_NTF, 31 YNL_ERROR_INV_RESP, 32}; 33 34/** 35 * struct ynl_error - error encountered by YNL 36 * @code: errno (low values) or YNL error code (enum ynl_error_code) 37 * @attr_offs: offset of bad attribute (for very advanced users) 38 * @msg: error message 39 * 40 * Error information for when YNL operations fail. 41 * Users should interact with the err member of struct ynl_sock directly. 42 * The main exception to that rule is ynl_sock_create(). 43 */ 44struct ynl_error { 45 enum ynl_error_code code; 46 unsigned int attr_offs; 47 char msg[512]; 48}; 49 50/** 51 * struct ynl_family - YNL family info 52 * Family description generated by codegen. Pass to ynl_sock_create(). 53 */ 54struct ynl_family { 55/* private: */ 56 const char *name; 57 const struct ynl_ntf_info *ntf_info; 58 unsigned int ntf_info_size; 59}; 60 61/** 62 * struct ynl_sock - YNL wrapped netlink socket 63 * @err: YNL error descriptor, cleared on every request. 64 */ 65struct ynl_sock { 66 struct ynl_error err; 67 68/* private: */ 69 const struct ynl_family *family; 70 struct mnl_socket *sock; 71 __u32 seq; 72 __u32 portid; 73 __u16 family_id; 74 75 unsigned int n_mcast_groups; 76 struct { 77 unsigned int id; 78 char name[GENL_NAMSIZ]; 79 } *mcast_groups; 80 81 struct ynl_ntf_base_type *ntf_first; 82 struct ynl_ntf_base_type **ntf_last_next; 83 84 struct nlmsghdr *nlh; 85 struct ynl_policy_nest *req_policy; 86 unsigned char *tx_buf; 87 unsigned char *rx_buf; 88 unsigned char raw_buf[]; 89}; 90 91struct ynl_sock * 92ynl_sock_create(const struct ynl_family *yf, struct ynl_error *e); 93void ynl_sock_destroy(struct ynl_sock *ys); 94 95#define ynl_dump_foreach(dump, iter) \ 96 for (typeof(dump->obj) *iter = &dump->obj; \ 97 !ynl_dump_obj_is_last(iter); \ 98 iter = ynl_dump_obj_next(iter)) 99 100int ynl_subscribe(struct ynl_sock *ys, const char *grp_name); 101int ynl_socket_get_fd(struct ynl_sock *ys); 102int ynl_ntf_check(struct ynl_sock *ys); 103 104/** 105 * ynl_has_ntf() - check if socket has *parsed* notifications 106 * @ys: active YNL socket 107 * 108 * Note that this does not take into account notifications sitting 109 * in netlink socket, just the notifications which have already been 110 * read and parsed (e.g. during a ynl_ntf_check() call). 111 */ 112static inline bool ynl_has_ntf(struct ynl_sock *ys) 113{ 114 return ys->ntf_last_next != &ys->ntf_first; 115} 116struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys); 117 118void ynl_ntf_free(struct ynl_ntf_base_type *ntf); 119 120/* 121 * YNL internals / low level stuff 122 */ 123 124/* Generic mnl helper code */ 125 126enum ynl_policy_type { 127 YNL_PT_REJECT = 1, 128 YNL_PT_IGNORE, 129 YNL_PT_NEST, 130 YNL_PT_FLAG, 131 YNL_PT_BINARY, 132 YNL_PT_U8, 133 YNL_PT_U16, 134 YNL_PT_U32, 135 YNL_PT_U64, 136 YNL_PT_NUL_STR, 137}; 138 139struct ynl_policy_attr { 140 enum ynl_policy_type type; 141 unsigned int len; 142 const char *name; 143 struct ynl_policy_nest *nest; 144}; 145 146struct ynl_policy_nest { 147 unsigned int max_attr; 148 struct ynl_policy_attr *table; 149}; 150 151struct ynl_parse_arg { 152 struct ynl_sock *ys; 153 struct ynl_policy_nest *rsp_policy; 154 void *data; 155}; 156 157struct ynl_dump_list_type { 158 struct ynl_dump_list_type *next; 159 unsigned char data[] __attribute__ ((aligned (8))); 160}; 161extern struct ynl_dump_list_type *YNL_LIST_END; 162 163static inline bool ynl_dump_obj_is_last(void *obj) 164{ 165 unsigned long uptr = (unsigned long)obj; 166 167 uptr -= offsetof(struct ynl_dump_list_type, data); 168 return uptr == (unsigned long)YNL_LIST_END; 169} 170 171static inline void *ynl_dump_obj_next(void *obj) 172{ 173 unsigned long uptr = (unsigned long)obj; 174 struct ynl_dump_list_type *list; 175 176 uptr -= offsetof(struct ynl_dump_list_type, data); 177 list = (void *)uptr; 178 uptr = (unsigned long)list->next; 179 uptr += offsetof(struct ynl_dump_list_type, data); 180 181 return (void *)uptr; 182} 183 184struct ynl_ntf_base_type { 185 __u16 family; 186 __u8 cmd; 187 struct ynl_ntf_base_type *next; 188 void (*free)(struct ynl_ntf_base_type *ntf); 189 unsigned char data[] __attribute__ ((aligned (8))); 190}; 191 192extern mnl_cb_t ynl_cb_array[NLMSG_MIN_TYPE]; 193 194struct nlmsghdr * 195ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version); 196struct nlmsghdr * 197ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version); 198 199int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr); 200 201int ynl_recv_ack(struct ynl_sock *ys, int ret); 202int ynl_cb_null(const struct nlmsghdr *nlh, void *data); 203 204/* YNL specific helpers used by the auto-generated code */ 205 206struct ynl_req_state { 207 struct ynl_parse_arg yarg; 208 mnl_cb_t cb; 209 __u32 rsp_cmd; 210}; 211 212struct ynl_dump_state { 213 struct ynl_sock *ys; 214 struct ynl_policy_nest *rsp_policy; 215 void *first; 216 struct ynl_dump_list_type *last; 217 size_t alloc_sz; 218 mnl_cb_t cb; 219 __u32 rsp_cmd; 220}; 221 222struct ynl_ntf_info { 223 struct ynl_policy_nest *policy; 224 mnl_cb_t cb; 225 size_t alloc_sz; 226 void (*free)(struct ynl_ntf_base_type *ntf); 227}; 228 229int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh, 230 struct ynl_req_state *yrs); 231int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh, 232 struct ynl_dump_state *yds); 233 234void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd); 235int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg); 236 237#endif 238