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         int                     flags;
  27 };
  28
  29 struct nlmsg_list {
  30         struct nlmsg_list *next;
  31         struct nlmsghdr   h;
  32 };
  33
  34 struct nlmsg_chain {
  35         struct nlmsg_list *head;
  36         struct nlmsg_list *tail;
  37 };
  38
  39 extern int rcvbuf;
  40
  41 int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
  42         __attribute__((warn_unused_result));
  43
  44 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
  45                              int protocol)
  46         __attribute__((warn_unused_result));
  47
  48 void rtnl_close(struct rtnl_handle *rth);
  49 int rtnl_wilddump_request(struct rtnl_handle *rth, int fam, int type)
  50         __attribute__((warn_unused_result));
  51 int rtnl_wilddump_req_filter(struct rtnl_handle *rth, int fam, int type,
  52                                     __u32 filt_mask)
  53         __attribute__((warn_unused_result));
  54
  55 typedef int (*req_filter_fn_t)(struct nlmsghdr *nlh, int reqlen);
  56
  57 int rtnl_wilddump_req_filter_fn(struct rtnl_handle *rth, int fam, int type,
  58                                 req_filter_fn_t fn)
  59         __attribute__((warn_unused_result));
  60 int rtnl_wilddump_stats_req_filter(struct rtnl_handle *rth, int fam, int type,
  61                                    __u32 filt_mask)
  62         __attribute__((warn_unused_result));
  63 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req,
  64                              int len)
  65         __attribute__((warn_unused_result));
  66 int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
  67         __attribute__((warn_unused_result));
  68
  69 struct rtnl_ctrl_data {
  70         int     nsid;
  71 };
  72
  73 typedef int (*rtnl_filter_t)(const struct sockaddr_nl *,
  74                              struct nlmsghdr *n, void *);
  75
  76 typedef int (*rtnl_listen_filter_t)(const struct sockaddr_nl *,
  77                                     struct rtnl_ctrl_data *,
  78                                     struct nlmsghdr *n, void *);
  79
  80 typedef int (*nl_ext_ack_fn_t)(const char *errmsg, uint32_t off,
  81                                const struct nlmsghdr *inner_nlh);
  82
  83 struct rtnl_dump_filter_arg {
  84         rtnl_filter_t filter;
  85         void *arg1;
  86         __u16 nc_flags;
  87 };
  88
  89 int rtnl_dump_filter_l(struct rtnl_handle *rth,
  90                               const struct rtnl_dump_filter_arg *arg);
  91 int rtnl_dump_filter_nc(struct rtnl_handle *rth,
  92                         rtnl_filter_t filter,
  93                         void *arg, __u16 nc_flags);
  94 #define rtnl_dump_filter(rth, filter, arg) \
  95         rtnl_dump_filter_nc(rth, filter, arg, 0)
  96 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
  97               struct nlmsghdr **answer)
  98         __attribute__((warn_unused_result));
  99 int rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iovec, size_t iovlen,
 100                   struct nlmsghdr **answer)
 101         __attribute__((warn_unused_result));
 102 int rtnl_talk_extack(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 103               struct nlmsghdr **answer, nl_ext_ack_fn_t errfn)
 104         __attribute__((warn_unused_result));
 105 int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 106                                    struct nlmsghdr **answer)
 107         __attribute__((warn_unused_result));
 108 int rtnl_send(struct rtnl_handle *rth, const void *buf, int)
 109         __attribute__((warn_unused_result));
 110 int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int)
 111         __attribute__((warn_unused_result));
 112
 113 int addattr(struct nlmsghdr *n, int maxlen, int type);
 114 int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data);
 115 int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data);
 116 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data);
 117 int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data);
 118 int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *data);
 119
 120 int addattr_l(struct nlmsghdr *n, int maxlen, int type,
 121               const void *data, int alen);
 122 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len);
 123 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type);
 124 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
 125 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
 126                                    const void *data, int len);
 127 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *nest);
 128 int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data);
 129 int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data);
 130 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data);
 131 int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data);
 132 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
 133                   const void *data, int alen);
 134
 135 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len);
 136 int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
 137                               int len, unsigned short flags);
 138 int parse_rtattr_byindex(struct rtattr *tb[], int max,
 139                          struct rtattr *rta, int len);
 140 struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len);
 141 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta, int len);
 142
 143 struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type);
 144 int rta_nest_end(struct rtattr *rta, struct rtattr *nest);
 145
 146 #define RTA_TAIL(rta) \
 147                 ((struct rtattr *) (((void *) (rta)) + \
 148                                     RTA_ALIGN((rta)->rta_len)))
 149
 150 #define parse_rtattr_nested(tb, max, rta) \
 151         (parse_rtattr((tb), (max), RTA_DATA(rta), RTA_PAYLOAD(rta)))
 152
 153 #define parse_rtattr_one_nested(type, rta) \
 154         (parse_rtattr_one(type, RTA_DATA(rta), RTA_PAYLOAD(rta)))
 155
 156 #define parse_rtattr_nested_compat(tb, max, rta, data, len) \
 157         ({ data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL;       \
 158                 __parse_rtattr_nested_compat(tb, max, rta, len); })
 159
 160 static inline __u8 rta_getattr_u8(const struct rtattr *rta)
 161 {
 162         return *(__u8 *)RTA_DATA(rta);
 163 }
 164 static inline __u16 rta_getattr_u16(const struct rtattr *rta)
 165 {
 166         return *(__u16 *)RTA_DATA(rta);
 167 }
 168 static inline __be16 rta_getattr_be16(const struct rtattr *rta)
 169 {
 170         return ntohs(rta_getattr_u16(rta));
 171 }
 172 static inline __u32 rta_getattr_u32(const struct rtattr *rta)
 173 {
 174         return *(__u32 *)RTA_DATA(rta);
 175 }
 176 static inline __be32 rta_getattr_be32(const struct rtattr *rta)
 177 {
 178         return ntohl(rta_getattr_u32(rta));
 179 }
 180 static inline __u64 rta_getattr_u64(const struct rtattr *rta)
 181 {
 182         __u64 tmp;
 183
 184         memcpy(&tmp, RTA_DATA(rta), sizeof(__u64));
 185         return tmp;
 186 }
 187 static inline const char *rta_getattr_str(const struct rtattr *rta)
 188 {
 189         return (const char *)RTA_DATA(rta);
 190 }
 191
 192 int rtnl_listen_all_nsid(struct rtnl_handle *);
 193 int rtnl_listen(struct rtnl_handle *, rtnl_listen_filter_t handler,
 194                 void *jarg);
 195 int rtnl_from_file(FILE *, rtnl_listen_filter_t handler,
 196                    void *jarg);
 197
 198 #define NLMSG_TAIL(nmsg) \
 199         ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
 200
 201 #ifndef IFA_RTA
 202 #define IFA_RTA(r) \
 203         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
 204 #endif
 205 #ifndef IFA_PAYLOAD
 206 #define IFA_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg))
 207 #endif
 208
 209 #ifndef IFLA_RTA
 210 #define IFLA_RTA(r) \
 211         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ifinfomsg))))
 212 #endif
 213 #ifndef IFLA_PAYLOAD
 214 #define IFLA_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg))
 215 #endif
 216
 217 #ifndef NDA_RTA
 218 #define NDA_RTA(r) \
 219         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
 220 #endif
 221 #ifndef NDA_PAYLOAD
 222 #define NDA_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct ndmsg))
 223 #endif
 224
 225 #ifndef NDTA_RTA
 226 #define NDTA_RTA(r) \
 227         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndtmsg))))
 228 #endif
 229 #ifndef NDTA_PAYLOAD
 230 #define NDTA_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct ndtmsg))
 231 #endif
 232
 233 #ifndef NETNS_RTA
 234 #define NETNS_RTA(r) \
 235         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))))
 236 #endif
 237 #ifndef NETNS_PAYLOAD
 238 #define NETNS_PAYLOAD(n)        NLMSG_PAYLOAD(n, sizeof(struct rtgenmsg))
 239 #endif
 240
 241 #ifndef IFLA_STATS_RTA
 242 #define IFLA_STATS_RTA(r) \
 243         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct if_stats_msg))))
 244 #endif
 245
 246 /* User defined nlmsg_type which is used mostly for logging netlink
 247  * messages from dump file */
 248 #define NLMSG_TSTAMP    15
 249
 250 #endif /* __LIBNETLINK_H__ */