zebra/kernel_netlink.h

   1 /* Declarations and definitions for kernel interaction over netlink
   2  * Copyright (C) 2016 Cumulus Networks, Inc.
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef _ZEBRA_KERNEL_NETLINK_H
  22 #define _ZEBRA_KERNEL_NETLINK_H
  23
  24 #ifdef __cplusplus
  25 extern "C" {
  26 #endif
  27
  28 #ifdef HAVE_NETLINK
  29
  30 #define NL_RCV_PKT_BUF_SIZE     32768
  31 #define NL_PKT_BUF_SIZE         8192
  32
  33 /*
  34  * nl_attr_put - add an attribute to the Netlink message.
  35  *
  36  * Returns true if the attribute could be added to the message (fits into the
  37  * buffer), otherwise false is returned.
  38  */
  39 extern bool nl_attr_put(struct nlmsghdr *n, unsigned int maxlen, int type,
  40                         const void *data, unsigned int alen);
  41 extern bool nl_attr_put8(struct nlmsghdr *n, unsigned int maxlen, int type,
  42                          uint8_t data);
  43 extern bool nl_attr_put16(struct nlmsghdr *n, unsigned int maxlen, int type,
  44                           uint16_t data);
  45 extern bool nl_attr_put32(struct nlmsghdr *n, unsigned int maxlen, int type,
  46                           uint32_t data);
  47
  48 /*
  49  * nl_attr_nest - start an attribute nest.
  50  *
  51  * Returns a valid pointer to the beginning of the nest if the attribute
  52  * describing the nest could be added to the message (fits into the buffer),
  53  * otherwise NULL is returned.
  54  */
  55 extern struct rtattr *nl_attr_nest(struct nlmsghdr *n, unsigned int maxlen,
  56                                    int type);
  57
  58 /*
  59  * nl_attr_nest_end - finalize nesting of attributes.
  60  *
  61  * Updates the length field of the attribute header to include the appeneded
  62  * attributes. Returns a total length of the Netlink message.
  63  */
  64 extern int nl_attr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
  65
  66 /*
  67  * nl_attr_rtnh - append a rtnexthop record to the Netlink message.
  68  *
  69  * Returns a valid pointer to the rtnexthop struct if it could be added to
  70  * the message (fits into the buffer), otherwise NULL is returned.
  71  */
  72 extern struct rtnexthop *nl_attr_rtnh(struct nlmsghdr *n, unsigned int maxlen);
  73
  74 /*
  75  * nl_attr_rtnh_end - finalize adding a rtnexthop record.
  76  *
  77  * Updates the length field of the rtnexthop to include the appeneded
  78  * attributes.
  79  */
  80 extern void nl_attr_rtnh_end(struct nlmsghdr *n, struct rtnexthop *rtnh);
  81
  82 extern void netlink_parse_rtattr(struct rtattr **tb, int max,
  83                                  struct rtattr *rta, int len);
  84 extern void netlink_parse_rtattr_flags(struct rtattr **tb, int max,
  85                                  struct rtattr *rta, int len,
  86                                  unsigned short flags);
  87 extern void netlink_parse_rtattr_nested(struct rtattr **tb, int max,
  88                                         struct rtattr *rta);
  89 extern const char *nl_msg_type_to_str(uint16_t msg_type);
  90 extern const char *nl_rtproto_to_str(uint8_t rtproto);
  91 extern const char *nl_family_to_str(uint8_t family);
  92 extern const char *nl_rttype_to_str(uint8_t rttype);
  93
  94 extern int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int),
  95                               const struct nlsock *nl,
  96                               const struct zebra_dplane_info *dp_info,
  97                               int count, bool startup);
  98 extern int netlink_talk_filter(struct nlmsghdr *h, ns_id_t ns, int startup);
  99 extern int netlink_talk(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
 100                         struct nlmsghdr *n, struct nlsock *nl,
 101                         struct zebra_ns *zns, bool startup);
 102 extern int netlink_request(struct nlsock *nl, void *req);
 103
 104 enum netlink_msg_status {
 105         FRR_NETLINK_SUCCESS,
 106         FRR_NETLINK_ERROR,
 107         FRR_NETLINK_QUEUED,
 108 };
 109
 110 struct nl_batch;
 111
 112 /*
 113  * netlink_batch_add_msg - add message to the netlink batch using dplane
 114  * context object.
 115  *
 116  * @ctx:         Dataplane context
 117  * @msg_encoder: A function that encodes dplane context object into
 118  *               netlink message. Should take dplane context object,
 119  *               pointer to a buffer and buffer's length as parameters
 120  *               and should return -1 on error, 0 on buffer overflow or
 121  *               size of the encoded message.
 122  * @ignore_res:  Whether the result of this message should be ignored.
 123  *               This should be used in some 'update' cases where we
 124  *               need to send two messages for one context object.
 125  *
 126  * Return:              Status of the message.
 127  */
 128 extern enum netlink_msg_status netlink_batch_add_msg(
 129         struct nl_batch *bth, struct zebra_dplane_ctx *ctx,
 130         ssize_t (*msg_encoder)(struct zebra_dplane_ctx *, void *, size_t),
 131         bool ignore_res);
 132
 133 /*
 134  * Vty/cli apis
 135  */
 136 extern int netlink_config_write_helper(struct vty *vty);
 137
 138 /*
 139  * Configure size of the batch buffer and sending threshold. If 'unset', reset
 140  * to default value.
 141  */
 142 extern void netlink_set_batch_buffer_size(uint32_t size, uint32_t threshold,
 143                                           bool set);
 144
 145 #endif /* HAVE_NETLINK */
 146
 147 #ifdef __cplusplus
 148 }
 149 #endif
 150
 151 #endif /* _ZEBRA_KERNEL_NETLINK_H */