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 int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn);
 113
 114 int addattr(struct nlmsghdr *n, int maxlen, int type);
 115 int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data);
 116 int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data);
 117 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data);
 118 int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data);
 119 int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *data);
 120
 121 int addattr_l(struct nlmsghdr *n, int maxlen, int type,
 122               const void *data, int alen);
 123 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len);
 124 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type);
 125 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
 126 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
 127                                    const void *data, int len);
 128 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *nest);
 129 int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data);
 130 int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data);
 131 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data);
 132 int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data);
 133 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
 134                   const void *data, int alen);
 135
 136 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len);
 137 int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
 138                               int len, unsigned short flags);
 139 int parse_rtattr_byindex(struct rtattr *tb[], int max,
 140                          struct rtattr *rta, int len);
 141 struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len);
 142 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta, int len);
 143
 144 struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type);
 145 int rta_nest_end(struct rtattr *rta, struct rtattr *nest);
 146
 147 #define RTA_TAIL(rta) \
 148                 ((struct rtattr *) (((void *) (rta)) + \
 149                                     RTA_ALIGN((rta)->rta_len)))
 150
 151 #define parse_rtattr_nested(tb, max, rta) \
 152         (parse_rtattr((tb), (max), RTA_DATA(rta), RTA_PAYLOAD(rta)))
 153
 154 #define parse_rtattr_one_nested(type, rta) \
 155         (parse_rtattr_one(type, RTA_DATA(rta), RTA_PAYLOAD(rta)))
 156
 157 #define parse_rtattr_nested_compat(tb, max, rta, data, len) \
 158         ({ data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL;       \
 159                 __parse_rtattr_nested_compat(tb, max, rta, len); })
 160
 161 static inline __u8 rta_getattr_u8(const struct rtattr *rta)
 162 {
 163         return *(__u8 *)RTA_DATA(rta);
 164 }
 165 static inline __u16 rta_getattr_u16(const struct rtattr *rta)
 166 {
 167         return *(__u16 *)RTA_DATA(rta);
 168 }
 169 static inline __be16 rta_getattr_be16(const struct rtattr *rta)
 170 {
 171         return ntohs(rta_getattr_u16(rta));
 172 }
 173 static inline __u32 rta_getattr_u32(const struct rtattr *rta)
 174 {
 175         return *(__u32 *)RTA_DATA(rta);
 176 }
 177 static inline __be32 rta_getattr_be32(const struct rtattr *rta)
 178 {
 179         return ntohl(rta_getattr_u32(rta));
 180 }
 181 static inline __u64 rta_getattr_u64(const struct rtattr *rta)
 182 {
 183         __u64 tmp;
 184
 185         memcpy(&tmp, RTA_DATA(rta), sizeof(__u64));
 186         return tmp;
 187 }
 188 static inline const char *rta_getattr_str(const struct rtattr *rta)
 189 {
 190         return (const char *)RTA_DATA(rta);
 191 }
 192
 193 int rtnl_listen_all_nsid(struct rtnl_handle *);
 194 int rtnl_listen(struct rtnl_handle *, rtnl_listen_filter_t handler,
 195                 void *jarg);
 196 int rtnl_from_file(FILE *, rtnl_listen_filter_t handler,
 197                    void *jarg);
 198
 199 #define NLMSG_TAIL(nmsg) \
 200         ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
 201
 202 #ifndef IFA_RTA
 203 #define IFA_RTA(r) \
 204         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
 205 #endif
 206 #ifndef IFA_PAYLOAD
 207 #define IFA_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct ifaddrmsg))
 208 #endif
 209
 210 #ifndef IFLA_RTA
 211 #define IFLA_RTA(r) \
 212         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ifinfomsg))))
 213 #endif
 214 #ifndef IFLA_PAYLOAD
 215 #define IFLA_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct ifinfomsg))
 216 #endif
 217
 218 #ifndef NDA_RTA
 219 #define NDA_RTA(r) \
 220         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
 221 #endif
 222 #ifndef NDA_PAYLOAD
 223 #define NDA_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct ndmsg))
 224 #endif
 225
 226 #ifndef NDTA_RTA
 227 #define NDTA_RTA(r) \
 228         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndtmsg))))
 229 #endif
 230 #ifndef NDTA_PAYLOAD
 231 #define NDTA_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct ndtmsg))
 232 #endif
 233
 234 #ifndef NETNS_RTA
 235 #define NETNS_RTA(r) \
 236         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))))
 237 #endif
 238 #ifndef NETNS_PAYLOAD
 239 #define NETNS_PAYLOAD(n)        NLMSG_PAYLOAD(n, sizeof(struct rtgenmsg))
 240 #endif
 241
 242 #ifndef IFLA_STATS_RTA
 243 #define IFLA_STATS_RTA(r) \
 244         ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct if_stats_msg))))
 245 #endif
 246
 247 /* User defined nlmsg_type which is used mostly for logging netlink
 248  * messages from dump file */
 249 #define NLMSG_TSTAMP    15
 250
 251 #endif /* __LIBNETLINK_H__ */