Man Pages

libnetlink(3) - phpMan libnetlink(3) - phpMan

Command: man perldoc info search(apropos)  


libnetlink(3)                                                    libnetlink(3)



NAME
       libnetlink - A library for accessing the netlink service

SYNOPSIS
       #include <asm/types.h>
       #include <libnetlink.h>
       #include <linux/netlink.h>
       #include <linux/rtnetlink.h>

       int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)

       int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)

       int rtnl_send(struct rtnl_handle *rth, char *buf, int len)

       int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)

       int rtnl_dump_filter(struct rtnl_handle *rth,
                      int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *),
                      void *arg1,
                      int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
                      void *arg2)

       int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
                  unsigned groups, struct nlmsghdr *answer,
                  int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
                  void *jarg)

       int rtnl_listen(struct rtnl_handle *rtnl,
                  int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
                  void *jarg)

       int rtnl_from_file(FILE *rtnl,
                  int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *),
                  void *jarg)

       int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)

       int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen)

       int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)

       int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen)

DESCRIPTION
       libnetlink  provides  a  higher  level interface to rtnetlink(7).  The read functions return 0 on success and a
       negative errno on failure.  The send functions return the amount of data sent, or -1 on error.

       rtnl_open
              Open a rtnetlink socket and save the state into the rth handle. This handle is passed to all  subsequent
              calls.  subscriptions is a bitmap of the rtnetlink multicast groups the socket will be a member of.


       rtnl_wilddump_request
              Request a full dump of the type database for family addresses.  type is a rtnetlink message type.


       rtnl_dump_request
              Request  a  full  dump of the type data buffer into buf with maximum length of len.  type is a rtnetlink
              message type.


       rtnl_dump_filter
              Receive netlink data after a request and filter it.  The filter callback checks if the received  message
              is  wanted.  It  gets  the source address of the message, the message itself and arg1 as arguments. 0 as
              return means that the filter passed, a negative value is returned by rtnl_dump_filter in case of  error.
              NULL  for  filter  means to not use a filter.  junk is used to filter messages not destined to the local
              socket.  Only one message bundle is received. Unless there is no message pending, this function does not
              block.


       rtnl_listen
              Receive  netlink  data after a request and pass it to handler.  handler is a callback that gets the mes-
              sage source address, the message itself, and the jarg cookie as arguments. It will get  called  for  all
              received  messages.   Only one message bundle is received. Unless there is no message pending this func-
              tion does not block.


       rtnl_from_file
              Works like rtnl_listen, but reads a netlink message bundle from the file file and passes the messages to
              handler for parsing. The file contains raw data as received from a rtnetlink socket.

       The  following  functions  are  useful to construct custom rtnetlink messages. For simple database dumping with
       filtering it is better to use the higher level functions above. See rtnetlink(3) and netlink(3) on how to  gen-
       erate  a rtnetlink message. The following utility functions require a continuous buffer that already contains a
       netlink message header and a rtnetlink request.


       rtnl_send
              Send the rtnetlink message in buf of length len to handle rth.


       addattr32
              Add a __u32 attribute of type type and with value data to netlink message n, which is part of  a  buffer
              of length maxlen.


       addattr_l
              Add  a  variable length attribute of type type and with value data and alen length to netlink message n,
              which is part of a buffer of length maxlen.  data is copied.


       rta_addattr32
              Initialize the rtnetlink attribute rta with a __u32 data value.


       rta_addattr32
              Initialize the rtnetlink attribute rta with a variable length data value.


BUGS
       The functions sometimes use fprintf and exit when a fatal error occurs.  This library should  be  named  librt-
       netlink.


AUTHORS
       netlink/rtnetlink was designed and written by Alexey Kuznetsov.  Andi Kleen wrote the man page.


SEE ALSO
       netlink(7), rtnetlink(7)
       /usr/include/linux/rtnetlink.h



                                                                 libnetlink(3)