include/libnetlink.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LIBNETLINK_H__
   3 #define __LIBNETLINK_H__ 1
   4
   5 #include <stdio.h>
   6 #include <string.h>
   7 #include <asm/types.h>
   8 #include <linux/netlink.h>
   9 #include <linux/rtnetlink.h>
  10 #include <linux/if_link.h>
  11 #include <linux/if_addr.h>
  12 #include <linux/neighbour.h>
  13 #include <linux/netconf.h>
  14 #include <arpa/inet.h>
  15
  16 struct rtnl_handle {
  17         int                     fd;
  18         struct sockaddr_nl      local;
  19         struct sockaddr_nl      peer;
  20         __u32                   seq;
  21         __u32                   dump;
  22         int                     proto;
  23         FILE                   *dump_fp;
  24 #define RTNL_HANDLE_F_LISTEN_ALL_NSID           0x01
  25 #define RTNL_HANDLE_F_SUPPRESS_NLERR            0x02
  26 #define RTNL_HANDLE_F_STRICT_CHK                0x04
  27         int                     flags;
  28 };
  29
  30 struct nlmsg_list {
  31         struct nlmsg_list *next;
  32         struct nlmsghdr   h;
  33 };
  34
  35 struct nlmsg_chain {
  36         struct nlmsg_list *head;
  37         struct nlmsg_list *tail;
  38 };
  39
  40 extern int rcvbuf;
  41
  42 int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
  43         __attribute__((warn_unused_result));
  44
  45 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
  46                              int protocol)
  47         __attribute__((warn_unused_result));
  48 int rtnl_add_nl_group(struct rtnl_handle *rth, unsigned int group)
  49         __attribute__((warn_unused_result));
  50 void rtnl_close(struct rtnl_handle *rth);
  51 void rtnl_set_strict_dump(struct rtnl_handle *rth);
  52
  53 typedef int (*req_filter_fn_t)(struct nlmsghdr *nlh, int reqlen);
  54
  55 int rtnl_addrdump_req(struct rtnl_handle *rth, int family,
  56                       req_filter_fn_t filter_fn)
  57         __attribute__((warn_unused_result));
  58 int rtnl_addrlbldump_req(struct rtnl_handle *rth, int family)
  59         __attribute__((warn_unused_result));
  60 int rtnl_routedump_req(struct rtnl_handle *rth, int family,
  61                        req_filter_fn_t filter_fn)
  62         __attribute__((warn_unused_result));
  63 int rtnl_ruledump_req(struct rtnl_handle *rth, int family)
  64         __attribute__((warn_unused_result));
  65 int rtnl_neighdump_req(struct rtnl_handle *rth, int family,
  66                        req_filter_fn_t filter_fn)
  67         __attribute__((warn_unused_result));
  68 int rtnl_neightbldump_req(struct rtnl_handle *rth, int family)
  69         __attribute__((warn_unused_result));
  70 int rtnl_mdbdump_req(struct rtnl_handle *rth, int family)
  71         __attribute__((warn_unused_result));
  72 int rtnl_netconfdump_req(struct rtnl_handle *rth, int family)
  73         __attribute__((warn_unused_result));
  74
  75 int rtnl_linkdump_req(struct rtnl_handle *rth, int fam)
  76         __attribute__((warn_unused_result));
  77 int rtnl_linkdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
  78         __attribute__((warn_unused_result));
  79
  80 int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int fam,
  81                                 req_filter_fn_t fn)
  82         __attribute__((warn_unused_result));
  83 int rtnl_fdb_linkdump_req_filter_fn(struct rtnl_handle *rth,
  84                                     req_filter_fn_t filter_fn)
  85         __attribute__((warn_unused_result));
  86 int rtnl_nsiddump_req_filter_fn(struct rtnl_handle *rth, int family,
  87                                 req_filter_fn_t filter_fn)
  88         __attribute__((warn_unused_result));
  89 int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
  90         __attribute__((warn_unused_result));
  91 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req,
  92                              int len)
  93         __attribute__((warn_unused_result));
  94 int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
  95         __attribute__((warn_unused_result));
  96
  97 int rtnl_nexthopdump_req(struct rtnl_handle *rth, int family,
  98                          req_filter_fn_t filter_fn)
  99         __attribute__((warn_unused_result));
 100
 101 struct rtnl_ctrl_data {
 102         int     nsid;
 103 };
 104
 105 typedef int (*rtnl_filter_t)(struct nlmsghdr *n, void *);
 106
 107 typedef int (*rtnl_listen_filter_t)(struct rtnl_ctrl_data *,
 108                                     struct nlmsghdr *n, void *);
 109
 110 typedef int (*nl_ext_ack_fn_t)(const char *errmsg, uint32_t off,
 111                                const struct nlmsghdr *inner_nlh);
 112
 113 struct rtnl_dump_filter_arg {
 114         rtnl_filter_t filter;
 115         void *arg1;
 116         __u16 nc_flags;
 117 };
 118
 119 int rtnl_dump_filter_nc(struct rtnl_handle *rth,
 120                         rtnl_filter_t filter,
 121                         void *arg, __u16 nc_flags);
 122 #define rtnl_dump_filter(rth, filter, arg) \
 123         rtnl_dump_filter_nc(rth, filter, arg, 0)
 124 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 125               struct nlmsghdr **answer)
 126         __attribute__((warn_unused_result));
 127 int rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iovec, size_t iovlen,
 128                   struct nlmsghdr **answer)
 129         __attribute__((warn_unused_result));
 130 int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 131                                    struct nlmsghdr **answer)
 132         __attribute__((warn_unused_result));
 133 int rtnl_send(struct rtnl_handle *rth, const void *buf, int)
 134         __attribute__((warn_unused_result));
 135 int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int)
 136         __attribute__((warn_unused_result));
 137 int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn);
 138 int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, int error);
 139
 140 int addattr(struct nlmsghdr *n, int maxlen, int type);
 141 int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data);
 142 int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data);
 143 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data);
 144 int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data);
 145 int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *data);
 146
 147 int addattr_l(struct nlmsghdr *n, int maxlen, int type,
 148               const void *data, int alen);
 149 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len);
 150 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type);
 151 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
 152 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
 153                                    const void *data, int len);
 154 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *nest);
 155 int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data);
 156 int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data);
 157 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data);
 158 int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data);
 159 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
 160                   const void *data, int alen);
 161
 162 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len);
 163 int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
 164                               int len, unsigned short flags);
 165 struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len);
 166 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta, int len);
 167
 168 struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type);
 169 int rta_nest_end(struct rtattr *rta, struct rtattr *nest);
 170
 171 #define RTA_TAIL(rta) \
 172                 ((struct rtattr *) (((void *) (rta)) + \
 173                                     RTA_ALIGN((rta)->rta_len)))
 174
 175 #define parse_rtattr_nested(tb, max, rta) \
 176         (parse_rtattr_flags((tb), (max), RTA_DATA(rta), RTA_PAYLOAD(rta), \
 177                             NLA_F_NESTED))
 178
 179 #define parse_rtattr_one_nested(type, rta) \
 180         (parse_rtattr_one(type, RTA_DATA(rta), RTA_PAYLOAD(rta)))
 181
 182 #define parse_rtattr_nested_compat(tb, max, rta, data, len) \
 183         ({ data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL;       \
 184                 __parse_rtattr_nested_compat(tb, max, rta, len); })
 185
 186 static inline __u8 rta_getattr_u8(const struct rtattr *rta)
 187 {
 188         return *(__u8 *)RTA_DATA(rta);
 189 }
 190 static inline __u16 rta_getattr_u16(const struct rtattr *rta)
 191 {
 192         return *(__u16 *)RTA_DATA(rta);
 193 }
 194 static inline __be16 rta_getattr_be16(const struct rtattr *rta)
 195 {
 196         return ntohs(rta_getattr_u16(rta));
 197 }
 198 static inline __u32 rta_getattr_u32(const struct rtattr *rta)
 199 {
 200         return *(__u32 *)RTA_DATA(rta);
 201 }
 202 static inline __be32 rta_getattr_be32(const struct rtattr *rta)
 203 {
 204         return ntohl(rta_getattr_u32(rta));
 205 }
 206 static inline __u64 rta_getattr_u64(const struct rtattr *rta)
 207 {
 208         __u64 tmp;
 209
 210         memcpy(&tmp, RTA_DATA(rta), sizeof(__u64));
 211         return tmp;
 212 }
 213 static inline __s32 rta_getattr_s32(const struct rtattr *rta)
 214 {
 215         return *(__s32 *)RTA_DATA(rta);
 216 }
 217 static inline __s64 rta_getattr_s64(const struct rtattr *rta)
 218 {
 219         __s64 tmp;
 220
 221         memcpy(&tmp, RTA_DATA(rta), sizeof(tmp));
 222         return tmp;
 223 }
 224 static inline const char *rta_getattr_str(const struct rtattr *rta)
 225 {
 226         return (const char *)RTA_DATA(rta);
 227 }
 228
 229 int rtnl_listen_all_nsid(struct rtnl_handle *);
 230 int rtnl_listen(struct rtnl_handle *, rtnl_listen_filter_t handler,
 231                 void *jarg);
 232 int rtnl_from_file(FILE *, rtnl_listen_filter_t handler,
 233                    void *jarg);
 234
 235 #define NLMSG_TAIL(nmsg) \
 236         ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
 237
 238 #ifndef IFA_RTA
 239 #define IFA_RTA(r) \
 240         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
 241 #endif
 242 #ifndef IFA_PAYLOAD
 243 #define IFA_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg))
 244 #endif
 245
 246 #ifndef IFLA_RTA
 247 #define IFLA_RTA(r) \
 248         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ifinfomsg))))
 249 #endif
 250 #ifndef IFLA_PAYLOAD
 251 #define IFLA_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg))
 252 #endif
 253
 254 #ifndef NDA_RTA
 255 #define NDA_RTA(r) \
 256         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
 257 #endif
 258 #ifndef NDA_PAYLOAD
 259 #define NDA_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct ndmsg))
 260 #endif
 261
 262 #ifndef NDTA_RTA
 263 #define NDTA_RTA(r) \
 264         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndtmsg))))
 265 #endif
 266 #ifndef NDTA_PAYLOAD
 267 #define NDTA_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct ndtmsg))
 268 #endif
 269
 270 #ifndef NETNS_RTA
 271 #define NETNS_RTA(r) \
 272         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))))
 273 #endif
 274 #ifndef NETNS_PAYLOAD
 275 #define NETNS_PAYLOAD(n)        NLMSG_PAYLOAD(n, sizeof(struct rtgenmsg))
 276 #endif
 277
 278 #ifndef IFLA_STATS_RTA
 279 #define IFLA_STATS_RTA(r) \
 280         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct if_stats_msg))))
 281 #endif
 282
 283 /* User defined nlmsg_type which is used mostly for logging netlink
 284  * messages from dump file */
 285 #define NLMSG_TSTAMP    15
 286
 287 #define rtattr_for_each_nested(attr, nest) \
 288         for ((attr) = (void *)RTA_DATA(nest); \
 289              RTA_OK(attr, RTA_PAYLOAD(nest) - ((char *)(attr) - (char *)RTA_DATA((nest)))); \
 290              (attr) = RTA_TAIL((attr)))
 291
 292 void nl_print_policy(const struct rtattr *attr, FILE *fp);
 293
 294 #endif /* __LIBNETLINK_H__ */