add libnl-tiny as a small replacement for libnl with only genl support included

SVN-Revision: 15507

1 files changed, 268 insertions, 0 deletions

diff --git a/package/libnl-tiny/src/genl.c b/package/libnl-tiny/src/genl.c
new file mode 100644
index 0000000..055be91
--- /dev/null
+++ b/package/libnl-tiny/src/genl.c
@@ -0,0 +1,268 @@
+/*
+ * 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;
+}
+
+/** @} */
+
+/** @} */