+++ /dev/null
-/*
- * lib/genl/genl.c Generic Netlink
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation version 2.1
- * of the License.
- *
- * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
- */
-
-/**
- * @defgroup genl Generic Netlink
- *
- * @par Message Format
- * @code
- * <------- NLMSG_ALIGN(hlen) ------> <---- NLMSG_ALIGN(len) --->
- * +----------------------------+- - -+- - - - - - - - - - -+- - -+
- * | Header | Pad | Payload | Pad |
- * | struct nlmsghdr | | | |
- * +----------------------------+- - -+- - - - - - - - - - -+- - -+
- * @endcode
- * @code
- * <-------- GENL_HDRLEN -------> <--- hdrlen -->
- * <------- genlmsg_len(ghdr) ------>
- * +------------------------+- - -+---------------+- - -+------------+
- * | Generic Netlink Header | Pad | Family Header | Pad | Attributes |
- * | struct genlmsghdr | | | | |
- * +------------------------+- - -+---------------+- - -+------------+
- * genlmsg_data(ghdr)--------------^ ^
- * genlmsg_attrdata(ghdr, hdrlen)-------------------------
- * @endcode
- *
- * @par Example
- * @code
- * #include <netlink/netlink.h>
- * #include <netlink/genl/genl.h>
- * #include <netlink/genl/ctrl.h>
- *
- * struct nl_sock *sock;
- * struct nl_msg *msg;
- * int family;
- *
- * // Allocate a new netlink socket
- * sock = nl_socket_alloc();
- *
- * // Connect to generic netlink socket on kernel side
- * genl_connect(sock);
- *
- * // Ask kernel to resolve family name to family id
- * family = genl_ctrl_resolve(sock, "generic_netlink_family_name");
- *
- * // Construct a generic netlink by allocating a new message, fill in
- * // the header and append a simple integer attribute.
- * msg = nlmsg_alloc();
- * genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, family, 0, NLM_F_ECHO,
- * CMD_FOO_GET, FOO_VERSION);
- * nla_put_u32(msg, ATTR_FOO, 123);
- *
- * // Send message over netlink socket
- * nl_send_auto_complete(sock, msg);
- *
- * // Free message
- * nlmsg_free(msg);
- *
- * // Prepare socket to receive the answer by specifying the callback
- * // function to be called for valid messages.
- * nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM, parse_cb, NULL);
- *
- * // Wait for the answer and receive it
- * nl_recvmsgs_default(sock);
- *
- * static int parse_cb(struct nl_msg *msg, void *arg)
- * {
- * struct nlmsghdr *nlh = nlmsg_hdr(msg);
- * struct nlattr *attrs[ATTR_MAX+1];
- *
- * // Validate message and parse attributes
- * genlmsg_parse(nlh, 0, attrs, ATTR_MAX, policy);
- *
- * if (attrs[ATTR_FOO]) {
- * uint32_t value = nla_get_u32(attrs[ATTR_FOO]);
- * ...
- * }
- *
- * return 0;
- * }
- * @endcode
- * @{
- */
-
-#include <netlink-generic.h>
-#include <netlink/netlink.h>
-#include <netlink/genl/genl.h>
-#include <netlink/utils.h>
-
-/**
- * @name Socket Creating
- * @{
- */
-
-int genl_connect(struct nl_sock *sk)
-{
- return nl_connect(sk, NETLINK_GENERIC);
-}
-
-/** @} */
-
-/**
- * @name Sending
- * @{
- */
-
-/**
- * Send trivial generic netlink message
- * @arg sk Netlink socket.
- * @arg family Generic netlink family
- * @arg cmd Command
- * @arg version Version
- * @arg flags Additional netlink message flags.
- *
- * Fills out a routing netlink request message and sends it out
- * using nl_send_simple().
- *
- * @return 0 on success or a negative error code.
- */
-int genl_send_simple(struct nl_sock *sk, int family, int cmd,
- int version, int flags)
-{
- struct genlmsghdr hdr = {
- .cmd = cmd,
- .version = version,
- };
-
- return nl_send_simple(sk, family, flags, &hdr, sizeof(hdr));
-}
-
-/** @} */
-
-
-/**
- * @name Message Parsing
- * @{
- */
-
-int genlmsg_valid_hdr(struct nlmsghdr *nlh, int hdrlen)
-{
- struct genlmsghdr *ghdr;
-
- if (!nlmsg_valid_hdr(nlh, GENL_HDRLEN))
- return 0;
-
- ghdr = nlmsg_data(nlh);
- if (genlmsg_len(ghdr) < NLMSG_ALIGN(hdrlen))
- return 0;
-
- return 1;
-}
-
-int genlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype,
- struct nla_policy *policy)
-{
- struct genlmsghdr *ghdr;
-
- if (!genlmsg_valid_hdr(nlh, hdrlen))
- return -NLE_MSG_TOOSHORT;
-
- ghdr = nlmsg_data(nlh);
- return nla_validate(genlmsg_attrdata(ghdr, hdrlen),
- genlmsg_attrlen(ghdr, hdrlen), maxtype, policy);
-}
-
-int genlmsg_parse(struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[],
- int maxtype, struct nla_policy *policy)
-{
- struct genlmsghdr *ghdr;
-
- if (!genlmsg_valid_hdr(nlh, hdrlen))
- return -NLE_MSG_TOOSHORT;
-
- ghdr = nlmsg_data(nlh);
- return nla_parse(tb, maxtype, genlmsg_attrdata(ghdr, hdrlen),
- genlmsg_attrlen(ghdr, hdrlen), policy);
-}
-
-/**
- * Get head of message payload
- * @arg gnlh genetlink messsage header
- */
-void *genlmsg_data(const struct genlmsghdr *gnlh)
-{
- return ((unsigned char *) gnlh + GENL_HDRLEN);
-}
-
-/**
- * Get lenght of message payload
- * @arg gnlh genetlink message header
- */
-int genlmsg_len(const struct genlmsghdr *gnlh)
-{
- struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
- NLMSG_HDRLEN);
- return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
-}
-
-/**
- * Get head of attribute data
- * @arg gnlh generic netlink message header
- * @arg hdrlen length of family specific header
- */
-struct nlattr *genlmsg_attrdata(const struct genlmsghdr *gnlh, int hdrlen)
-{
- return genlmsg_data(gnlh) + NLMSG_ALIGN(hdrlen);
-}
-
-/**
- * Get length of attribute data
- * @arg gnlh generic netlink message header
- * @arg hdrlen length of family specific header
- */
-int genlmsg_attrlen(const struct genlmsghdr *gnlh, int hdrlen)
-{
- return genlmsg_len(gnlh) - NLMSG_ALIGN(hdrlen);
-}
-
-/** @} */
-
-/**
- * @name Message Building
- * @{
- */
-
-/**
- * Add generic netlink header to netlink message
- * @arg msg netlink message
- * @arg pid netlink process id or NL_AUTO_PID
- * @arg seq sequence number of message or NL_AUTO_SEQ
- * @arg family generic netlink family
- * @arg hdrlen length of user specific header
- * @arg flags message flags
- * @arg cmd generic netlink command
- * @arg version protocol version
- *
- * Returns pointer to user specific header.
- */
-void *genlmsg_put(struct nl_msg *msg, uint32_t pid, uint32_t seq, int family,
- int hdrlen, int flags, uint8_t cmd, uint8_t version)
-{
- struct nlmsghdr *nlh;
- struct genlmsghdr hdr = {
- .cmd = cmd,
- .version = version,
- };
-
- nlh = nlmsg_put(msg, pid, seq, family, GENL_HDRLEN + hdrlen, flags);
- if (nlh == NULL)
- return NULL;
-
- memcpy(nlmsg_data(nlh), &hdr, sizeof(hdr));
- NL_DBG(2, "msg %p: Added generic netlink header cmd=%d version=%d\n",
- msg, cmd, version);
-
- return nlmsg_data(nlh) + GENL_HDRLEN;
-}
-
-/** @} */
-
-/** @} */
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