plucky (3) libnetlink.3.gz

Provided by: iproute2_6.13.0-1ubuntu1_amd64 bug

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 rtnl_ctrl_data *,
                           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. If there
              is a 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
              message  source address, anscillary data, the message itself, and the jarg cookie as arguments. It
              will get called for all received messages.  Only one message bundle is received.  If  there  is  a
              message pending this function 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 should contain 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  generate  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

       This library is meant for internal use, use libmnl for new programs.

       The functions sometimes use fprintf and exit when a fatal error occurs.  This  library  should  be  named
       librtnetlink.

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)