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Diffstat (limited to 'man/man3/libnetlink.3')
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diff --git a/man/man3/libnetlink.3 b/man/man3/libnetlink.3 new file mode 100644 index 0000000..9a2c801 --- /dev/null +++ b/man/man3/libnetlink.3 @@ -0,0 +1,200 @@ +.TH libnetlink 3 +.SH NAME +libnetlink \- A library for accessing the netlink service +.SH SYNOPSIS +.nf +#include <asm/types.h> +.br +#include <libnetlink.h> +.br +#include <linux/netlink.h> +.br +#include <linux/rtnetlink.h> +.sp +int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions) +.sp +int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type) +.sp +int rtnl_send(struct rtnl_handle *rth, char *buf, int len) +.sp +int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len) +.sp +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) +.sp +int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer, + unsigned groups, struct nlmsghdr *answer, +.br + int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *), +.br + void *jarg) +.sp +int rtnl_listen(struct rtnl_handle *rtnl, + int (*handler)(struct sockaddr_nl *, struct rtnl_ctrl_data *, + struct nlmsghdr *n, void *), + void *jarg) +.sp +int rtnl_from_file(FILE *rtnl, + int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *), + void *jarg) +.sp +int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data) +.sp +int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen) +.sp +int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data) +.sp +int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen) +.SH DESCRIPTION +libnetlink provides a higher level interface to +.BR 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. +.TP +rtnl_open +Open a rtnetlink socket and save the state into the +.B rth +handle. This handle is passed to all subsequent calls. +.B subscriptions +is a bitmap of the rtnetlink multicast groups the socket will be +a member of. + +.TP +rtnl_wilddump_request +Request a full dump of the +.B type +database for +.B family +addresses. +.B type +is a rtnetlink message type. +.\" XXX + +.TP +rtnl_dump_request +Request a full dump of the +.B type +data buffer into +.B buf +with maximum length of +.B len. +.B type +is a rtnetlink message type. + +.TP +rtnl_dump_filter +Receive netlink data after a request and filter it. +The +.B filter +callback checks if the received message is wanted. It gets the source +address of the message, the message itself and +.B arg1 +as arguments. 0 as return means that the filter passed, a negative +value is returned +by +.I rtnl_dump_filter +in case of error. NULL for +.I filter +means to not use a filter. +.B 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. + +.TP +rtnl_listen +Receive netlink data after a request and pass it to +.I handler. +.B handler +is a callback that gets the message source address, anscillary data, the message +itself, and the +.B 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. + +.TP +rtnl_from_file +Works like +.I rtnl_listen, +but reads a netlink message bundle from the file +.B file +and passes the messages to +.B handler +for parsing. The file should contain raw data as received from a rtnetlink socket. +.PP +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 +.BR rtnetlink (3) +and +.BR 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. + +.TP +rtnl_send +Send the rtnetlink message in +.B buf +of length +.B len +to handle +.B rth. + +.TP +addattr32 +Add a __u32 attribute of type +.B type +and with value +.B data +to netlink message +.B n, +which is part of a buffer of length +.B maxlen. + +.TP +addattr_l +Add a variable length attribute of type +.B type +and with value +.B data +and +.B alen +length to netlink message +.B n, +which is part of a buffer of length +.B maxlen. +.B data +is copied. + +.TP +rta_addattr32 +Initialize the rtnetlink attribute +.B rta +with a __u32 data value. + +.TP +rta_addattr32 +Initialize the rtnetlink attribute +.B rta +with a variable length data value. + +.SH 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. + +.SH AUTHORS +netlink/rtnetlink was designed and written by Alexey Kuznetsov. +Andi Kleen wrote the man page. + +.SH SEE ALSO +.BR netlink (7), +.BR rtnetlink (7) +.br +/usr/include/linux/rtnetlink.h |