zebra/kernel_netlink.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Declarations and definitions for kernel interaction over netlink
   3  * Copyright (C) 2016 Cumulus Networks, Inc.
   4  */
   5
   6 #ifndef _ZEBRA_KERNEL_NETLINK_H
   7 #define _ZEBRA_KERNEL_NETLINK_H
   8
   9 #ifdef __cplusplus
  10 extern "C" {
  11 #endif
  12
  13 #ifdef HAVE_NETLINK
  14
  15 #define RTM_NHA(h)                                                             \
  16         ((struct rtattr *)(((char *)(h)) + NLMSG_ALIGN(sizeof(struct nhmsg))))
  17
  18
  19 #define NL_RCV_PKT_BUF_SIZE     (34 * 1024)
  20 #define NL_PKT_BUF_SIZE         8192
  21
  22 /*
  23  * nl_attr_put - add an attribute to the Netlink message.
  24  *
  25  * Returns true if the attribute could be added to the message (fits into the
  26  * buffer), otherwise false is returned.
  27  */
  28 extern bool nl_attr_put(struct nlmsghdr *n, unsigned int maxlen, int type,
  29                         const void *data, unsigned int alen);
  30 extern bool nl_attr_put8(struct nlmsghdr *n, unsigned int maxlen, int type,
  31                          uint8_t data);
  32 extern bool nl_attr_put16(struct nlmsghdr *n, unsigned int maxlen, int type,
  33                           uint16_t data);
  34 extern bool nl_attr_put32(struct nlmsghdr *n, unsigned int maxlen, int type,
  35                           uint32_t data);
  36 extern bool nl_attr_put64(struct nlmsghdr *n, unsigned int maxlen, int type,
  37                           uint64_t data);
  38
  39 /*
  40  * nl_attr_nest - start an attribute nest.
  41  *
  42  * Returns a valid pointer to the beginning of the nest if the attribute
  43  * describing the nest could be added to the message (fits into the buffer),
  44  * otherwise NULL is returned.
  45  */
  46 extern struct rtattr *nl_attr_nest(struct nlmsghdr *n, unsigned int maxlen,
  47                                    int type);
  48
  49 /*
  50  * nl_attr_nest_end - finalize nesting of attributes.
  51  *
  52  * Updates the length field of the attribute header to include the appeneded
  53  * attributes. Returns a total length of the Netlink message.
  54  */
  55 extern int nl_attr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
  56
  57 /*
  58  * nl_attr_rtnh - append a rtnexthop record to the Netlink message.
  59  *
  60  * Returns a valid pointer to the rtnexthop struct if it could be added to
  61  * the message (fits into the buffer), otherwise NULL is returned.
  62  */
  63 extern struct rtnexthop *nl_attr_rtnh(struct nlmsghdr *n, unsigned int maxlen);
  64
  65 /*
  66  * nl_attr_rtnh_end - finalize adding a rtnexthop record.
  67  *
  68  * Updates the length field of the rtnexthop to include the appeneded
  69  * attributes.
  70  */
  71 extern void nl_attr_rtnh_end(struct nlmsghdr *n, struct rtnexthop *rtnh);
  72
  73 extern void netlink_parse_rtattr(struct rtattr **tb, int max,
  74                                  struct rtattr *rta, int len);
  75 extern void netlink_parse_rtattr_flags(struct rtattr **tb, int max,
  76                                  struct rtattr *rta, int len,
  77                                  unsigned short flags);
  78 extern void netlink_parse_rtattr_nested(struct rtattr **tb, int max,
  79                                         struct rtattr *rta);
  80 /*
  81  * nl_addraw_l copies raw form the netlink message buffer into netlink
  82  * message header pointer. It ensures the aligned data buffer does not
  83  * override past max length.
  84  * return value is 0 if its successful
  85  */
  86 extern bool nl_addraw_l(struct nlmsghdr *n, unsigned int maxlen,
  87                         const void *data, unsigned int len);
  88 /*
  89  * nl_rta_put - add an additional optional attribute(rtattr) to the
  90  * Netlink message buffer.
  91  *
  92  * Returns true if the attribute could be added to the message (fits into the
  93  * buffer), otherwise false is returned.
  94  */
  95 extern bool nl_rta_put(struct rtattr *rta, unsigned int maxlen, int type,
  96                        const void *data, int alen);
  97 extern bool nl_rta_put16(struct rtattr *rta, unsigned int maxlen, int type,
  98                          uint16_t data);
  99 extern bool nl_rta_put64(struct rtattr *rta, unsigned int maxlen, int type,
 100                          uint64_t data);
 101 /*
 102  * nl_rta_nest - start an additional optional attribute (rtattr) nest.
 103  *
 104  * Returns a valid pointer to the beginning of the nest if the attribute
 105  * describing the nest could be added to the message (fits into the buffer),
 106  * otherwise NULL is returned.
 107  */
 108 extern struct rtattr *nl_rta_nest(struct rtattr *rta, unsigned int maxlen,
 109                                   int type);
 110 /*
 111  * nl_rta_nest_end - finalize nesting of an aditionl optionl attributes.
 112  *
 113  * Updates the length field of the attribute header to include the appeneded
 114  * attributes. Returns a total length of the Netlink message.
 115  */
 116 extern int nl_rta_nest_end(struct rtattr *rta, struct rtattr *nest);
 117 extern const char *nl_msg_type_to_str(uint16_t msg_type);
 118 extern const char *nl_rtproto_to_str(uint8_t rtproto);
 119 extern const char *nl_family_to_str(uint8_t family);
 120 extern const char *nl_rttype_to_str(uint8_t rttype);
 121
 122 extern int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int),
 123                               struct nlsock *nl,
 124                               const struct zebra_dplane_info *dp_info,
 125                               int count, bool startup);
 126 extern int netlink_talk_filter(struct nlmsghdr *h, ns_id_t ns, int startup);
 127 extern int netlink_talk(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
 128                         struct nlmsghdr *n, struct nlsock *nl,
 129                         struct zebra_ns *zns, bool startup);
 130 extern int netlink_request(struct nlsock *nl, void *req);
 131
 132 enum netlink_msg_status {
 133         FRR_NETLINK_SUCCESS,
 134         FRR_NETLINK_ERROR,
 135         FRR_NETLINK_QUEUED,
 136 };
 137
 138 struct nl_batch;
 139
 140 /*
 141  * netlink_batch_add_msg - add message to the netlink batch using dplane
 142  * context object.
 143  *
 144  * @ctx:         Dataplane context
 145  * @msg_encoder: A function that encodes dplane context object into
 146  *               netlink message. Should take dplane context object,
 147  *               pointer to a buffer and buffer's length as parameters
 148  *               and should return -1 on error, 0 on buffer overflow or
 149  *               size of the encoded message.
 150  * @ignore_res:  Whether the result of this message should be ignored.
 151  *               This should be used in some 'update' cases where we
 152  *               need to send two messages for one context object.
 153  *
 154  * Return:              Status of the message.
 155  */
 156 extern enum netlink_msg_status netlink_batch_add_msg(
 157         struct nl_batch *bth, struct zebra_dplane_ctx *ctx,
 158         ssize_t (*msg_encoder)(struct zebra_dplane_ctx *, void *, size_t),
 159         bool ignore_res);
 160
 161 /*
 162  * Vty/cli apis
 163  */
 164 extern int netlink_config_write_helper(struct vty *vty);
 165
 166 /*
 167  * Configure size of the batch buffer and sending threshold. If 'unset', reset
 168  * to default value.
 169  */
 170 extern void netlink_set_batch_buffer_size(uint32_t size, uint32_t threshold,
 171                                           bool set);
 172
 173 extern struct nlsock *kernel_netlink_nlsock_lookup(int sock);
 174 #endif /* HAVE_NETLINK */
 175
 176 #ifdef __cplusplus
 177 }
 178 #endif
 179
 180 #endif /* _ZEBRA_KERNEL_NETLINK_H */