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     (34 * 1024)
  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 extern bool nl_attr_put64(struct nlmsghdr *n, unsigned int maxlen, int type,
  52                           uint64_t data);
  53
  54 /*
  55  * nl_attr_nest - start an attribute nest.
  56  *
  57  * Returns a valid pointer to the beginning of the nest if the attribute
  58  * describing the nest could be added to the message (fits into the buffer),
  59  * otherwise NULL is returned.
  60  */
  61 extern struct rtattr *nl_attr_nest(struct nlmsghdr *n, unsigned int maxlen,
  62                                    int type);
  63
  64 /*
  65  * nl_attr_nest_end - finalize nesting of attributes.
  66  *
  67  * Updates the length field of the attribute header to include the appeneded
  68  * attributes. Returns a total length of the Netlink message.
  69  */
  70 extern int nl_attr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
  71
  72 /*
  73  * nl_attr_rtnh - append a rtnexthop record to the Netlink message.
  74  *
  75  * Returns a valid pointer to the rtnexthop struct if it could be added to
  76  * the message (fits into the buffer), otherwise NULL is returned.
  77  */
  78 extern struct rtnexthop *nl_attr_rtnh(struct nlmsghdr *n, unsigned int maxlen);
  79
  80 /*
  81  * nl_attr_rtnh_end - finalize adding a rtnexthop record.
  82  *
  83  * Updates the length field of the rtnexthop to include the appeneded
  84  * attributes.
  85  */
  86 extern void nl_attr_rtnh_end(struct nlmsghdr *n, struct rtnexthop *rtnh);
  87
  88 extern void netlink_parse_rtattr(struct rtattr **tb, int max,
  89                                  struct rtattr *rta, int len);
  90 extern void netlink_parse_rtattr_flags(struct rtattr **tb, int max,
  91                                  struct rtattr *rta, int len,
  92                                  unsigned short flags);
  93 extern void netlink_parse_rtattr_nested(struct rtattr **tb, int max,
  94                                         struct rtattr *rta);
  95 /*
  96  * nl_addraw_l copies raw form the netlink message buffer into netlink
  97  * message header pointer. It ensures the aligned data buffer does not
  98  * override past max length.
  99  * return value is 0 if its successful
 100  */
 101 extern bool nl_addraw_l(struct nlmsghdr *n, unsigned int maxlen,
 102                         const void *data, unsigned int len);
 103 /*
 104  * nl_rta_put - add an additional optional attribute(rtattr) to the
 105  * Netlink message buffer.
 106  *
 107  * Returns true if the attribute could be added to the message (fits into the
 108  * buffer), otherwise false is returned.
 109  */
 110 extern bool nl_rta_put(struct rtattr *rta, unsigned int maxlen, int type,
 111                        const void *data, int alen);
 112 extern bool nl_rta_put16(struct rtattr *rta, unsigned int maxlen, int type,
 113                          uint16_t data);
 114 extern bool nl_rta_put64(struct rtattr *rta, unsigned int maxlen, int type,
 115                          uint64_t data);
 116 /*
 117  * nl_rta_nest - start an additional optional attribute (rtattr) nest.
 118  *
 119  * Returns a valid pointer to the beginning of the nest if the attribute
 120  * describing the nest could be added to the message (fits into the buffer),
 121  * otherwise NULL is returned.
 122  */
 123 extern struct rtattr *nl_rta_nest(struct rtattr *rta, unsigned int maxlen,
 124                                   int type);
 125 /*
 126  * nl_rta_nest_end - finalize nesting of an aditionl optionl attributes.
 127  *
 128  * Updates the length field of the attribute header to include the appeneded
 129  * attributes. Returns a total length of the Netlink message.
 130  */
 131 extern int nl_rta_nest_end(struct rtattr *rta, struct rtattr *nest);
 132 extern const char *nl_msg_type_to_str(uint16_t msg_type);
 133 extern const char *nl_rtproto_to_str(uint8_t rtproto);
 134 extern const char *nl_family_to_str(uint8_t family);
 135 extern const char *nl_rttype_to_str(uint8_t rttype);
 136
 137 extern int netlink_parse_info(int (*filter)(struct nlmsghdr *, ns_id_t, int),
 138                               struct nlsock *nl,
 139                               const struct zebra_dplane_info *dp_info,
 140                               int count, bool startup);
 141 extern int netlink_talk_filter(struct nlmsghdr *h, ns_id_t ns, int startup);
 142 extern int netlink_talk(int (*filter)(struct nlmsghdr *, ns_id_t, int startup),
 143                         struct nlmsghdr *n, struct nlsock *nl,
 144                         struct zebra_ns *zns, bool startup);
 145 extern int netlink_request(struct nlsock *nl, void *req);
 146
 147 enum netlink_msg_status {
 148         FRR_NETLINK_SUCCESS,
 149         FRR_NETLINK_ERROR,
 150         FRR_NETLINK_QUEUED,
 151 };
 152
 153 struct nl_batch;
 154
 155 /*
 156  * netlink_batch_add_msg - add message to the netlink batch using dplane
 157  * context object.
 158  *
 159  * @ctx:         Dataplane context
 160  * @msg_encoder: A function that encodes dplane context object into
 161  *               netlink message. Should take dplane context object,
 162  *               pointer to a buffer and buffer's length as parameters
 163  *               and should return -1 on error, 0 on buffer overflow or
 164  *               size of the encoded message.
 165  * @ignore_res:  Whether the result of this message should be ignored.
 166  *               This should be used in some 'update' cases where we
 167  *               need to send two messages for one context object.
 168  *
 169  * Return:              Status of the message.
 170  */
 171 extern enum netlink_msg_status netlink_batch_add_msg(
 172         struct nl_batch *bth, struct zebra_dplane_ctx *ctx,
 173         ssize_t (*msg_encoder)(struct zebra_dplane_ctx *, void *, size_t),
 174         bool ignore_res);
 175
 176 /*
 177  * Vty/cli apis
 178  */
 179 extern int netlink_config_write_helper(struct vty *vty);
 180
 181 /*
 182  * Configure size of the batch buffer and sending threshold. If 'unset', reset
 183  * to default value.
 184  */
 185 extern void netlink_set_batch_buffer_size(uint32_t size, uint32_t threshold,
 186                                           bool set);
 187
 188 extern struct nlsock *kernel_netlink_nlsock_lookup(int sock);
 189 #endif /* HAVE_NETLINK */
 190
 191 #ifdef __cplusplus
 192 }
 193 #endif
 194
 195 #endif /* _ZEBRA_KERNEL_NETLINK_H */