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 RTM_NHA(h)                                                             \
  31         ((struct rtattr *)(((char *)(h)) + NLMSG_ALIGN(sizeof(struct nhmsg))))
  32
  33
  34 #define NL_RCV_PKT_BUF_SIZE     32768
  35 #define NL_PKT_BUF_SIZE         8192
  36
  37 /*
  38  * nl_attr_put - add an attribute to the Netlink message.
  39  *
  40  * Returns true if the attribute could be added to the message (fits into the
  41  * buffer), otherwise false is returned.
  42  */
  43 extern bool nl_attr_put(struct nlmsghdr *n, unsigned int maxlen, int type,
  44                         const void *data, unsigned int alen);
  45 extern bool nl_attr_put8(struct nlmsghdr *n, unsigned int maxlen, int type,
  46                          uint8_t data);
  47 extern bool nl_attr_put16(struct nlmsghdr *n, unsigned int maxlen, int type,
  48                           uint16_t data);
  49 extern bool nl_attr_put32(struct nlmsghdr *n, unsigned int maxlen, int type,
  50                           uint32_t data);
  51
  52 /*
  53  * nl_attr_nest - start an attribute nest.
  54  *
  55  * Returns a valid pointer to the beginning of the nest if the attribute
  56  * describing the nest could be added to the message (fits into the buffer),
  57  * otherwise NULL is returned.
  58  */
  59 extern struct rtattr *nl_attr_nest(struct nlmsghdr *n, unsigned int maxlen,
  60                                    int type);
  61
  62 /*
  63  * nl_attr_nest_end - finalize nesting of attributes.
  64  *
  65  * Updates the length field of the attribute header to include the appeneded
  66  * attributes. Returns a total length of the Netlink message.
  67  */
  68 extern int nl_attr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
  69
  70 /*
  71  * nl_attr_rtnh - append a rtnexthop record to the Netlink message.
  72  *
  73  * Returns a valid pointer to the rtnexthop struct if it could be added to
  74  * the message (fits into the buffer), otherwise NULL is returned.
  75  */
  76 extern struct rtnexthop *nl_attr_rtnh(struct nlmsghdr *n, unsigned int maxlen);
  77
  78 /*
  79  * nl_attr_rtnh_end - finalize adding a rtnexthop record.
  80  *
  81  * Updates the length field of the rtnexthop to include the appeneded
  82  * attributes.
  83  */
  84 extern void nl_attr_rtnh_end(struct nlmsghdr *n, struct rtnexthop *rtnh);
  85
  86 extern void netlink_parse_rtattr(struct rtattr **tb, int max,
  87                                  struct rtattr *rta, int len);
  88 extern void netlink_parse_rtattr_flags(struct rtattr **tb, int max,
  89                                  struct rtattr *rta, int len,
  90                                  unsigned short flags);
  91 extern void netlink_parse_rtattr_nested(struct rtattr **tb, int max,
  92                                         struct rtattr *rta);
  93 /*
  94  * nl_addraw_l copies raw form the netlink message buffer into netlink
  95  * message header pointer. It ensures the aligned data buffer does not
  96  * override past max length.
  97  * return value is 0 if its successful
  98  */
  99 extern bool nl_addraw_l(struct nlmsghdr *n, unsigned int maxlen,
 100                         const void *data, unsigned int len);
 101 /*
 102  * nl_rta_put - add an additional optional attribute(rtattr) to the
 103  * Netlink message buffer.
 104  *
 105  * Returns true if the attribute could be added to the message (fits into the
 106  * buffer), otherwise false is returned.
 107  */
 108 extern bool nl_rta_put(struct rtattr *rta, unsigned int maxlen, int type,
 109                        const void *data, int alen);
 110 extern bool nl_rta_put16(struct rtattr *rta, unsigned int maxlen, int type,
 111                          uint16_t data);
 112 extern bool nl_rta_put64(struct rtattr *rta, unsigned int maxlen, int type,
 113                          uint64_t data);
 114 /*
 115  * nl_rta_nest - start an additional optional attribute (rtattr) nest.
 116  *
 117  * Returns a valid pointer to the beginning of the nest if the attribute
 118  * describing the nest could be added to the message (fits into the buffer),
 119  * otherwise NULL is returned.
 120  */
 121 extern struct rtattr *nl_rta_nest(struct rtattr *rta, unsigned int maxlen,
 122                                   int type);
 123 /*
 124  * nl_rta_nest_end - finalize nesting of an aditionl optionl attributes.
 125  *
 126  * Updates the length field of the attribute header to include the appeneded
 127  * attributes. Returns a total length of the Netlink message.
 128  */
 129 extern int nl_rta_nest_end(struct rtattr *rta, struct rtattr *nest);
 130 extern const char *nl_msg_type_to_str(uint16_t msg_type);
 131 extern const char *nl_rtproto_to_str(uint8_t rtproto);
 132 extern const char *nl_family_to_str(uint8_t family);
 133 extern const char *nl_rttype_to_str(uint8_t rttype);
 134
 135 extern int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int),
 136                               struct nlsock *nl,
 137                               const struct zebra_dplane_info *dp_info,
 138                               int count, bool startup);
 139 extern int netlink_talk_filter(struct nlmsghdr *h, ns_id_t ns, int startup);
 140 extern int netlink_talk(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
 141                         struct nlmsghdr *n, struct nlsock *nl,
 142                         struct zebra_ns *zns, bool startup);
 143 extern int netlink_request(struct nlsock *nl, void *req);
 144
 145 enum netlink_msg_status {
 146         FRR_NETLINK_SUCCESS,
 147         FRR_NETLINK_ERROR,
 148         FRR_NETLINK_QUEUED,
 149 };
 150
 151 struct nl_batch;
 152
 153 /*
 154  * netlink_batch_add_msg - add message to the netlink batch using dplane
 155  * context object.
 156  *
 157  * @ctx:         Dataplane context
 158  * @msg_encoder: A function that encodes dplane context object into
 159  *               netlink message. Should take dplane context object,
 160  *               pointer to a buffer and buffer's length as parameters
 161  *               and should return -1 on error, 0 on buffer overflow or
 162  *               size of the encoded message.
 163  * @ignore_res:  Whether the result of this message should be ignored.
 164  *               This should be used in some 'update' cases where we
 165  *               need to send two messages for one context object.
 166  *
 167  * Return:              Status of the message.
 168  */
 169 extern enum netlink_msg_status netlink_batch_add_msg(
 170         struct nl_batch *bth, struct zebra_dplane_ctx *ctx,
 171         ssize_t (*msg_encoder)(struct zebra_dplane_ctx *, void *, size_t),
 172         bool ignore_res);
 173
 174 /*
 175  * Vty/cli apis
 176  */
 177 extern int netlink_config_write_helper(struct vty *vty);
 178
 179 /*
 180  * Configure size of the batch buffer and sending threshold. If 'unset', reset
 181  * to default value.
 182  */
 183 extern void netlink_set_batch_buffer_size(uint32_t size, uint32_t threshold,
 184                                           bool set);
 185
 186 extern struct nlsock *kernel_netlink_nlsock_lookup(int sock);
 187 #endif /* HAVE_NETLINK */
 188
 189 #ifdef __cplusplus
 190 }
 191 #endif
 192
 193 #endif /* _ZEBRA_KERNEL_NETLINK_H */