introduce sit tunnel support

This patch introduces sit tunnel support

Signed-off-by: Susant Sahani <susant@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
[thaller@redhat.com: change WS to TAB, fix code doc]
Signed-off-by: Thomas Haller <thaller@redhat.com>

1 files changed, 624 insertions, 0 deletions

diff --git a/lib/route/link/sit.c b/lib/route/link/sit.c
new file mode 100644
index 0000000..694c177
--- /dev/null
+++ b/lib/route/link/sit.c
@@ -0,0 +1,624 @@
+/*
+ * lib/route/link/sit.c        SIT Link Info
+ *
+ *      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) 2014 Susant Sahani <susant@redhat.com>
+ */
+
+/**
+ * @ingroup link
+ * @defgroup sit SIT
+ * sit link module
+ *
+ * @details
+ * \b Link Type Name: "sit"
+ *
+ * @route_doc{link_sit, SIT Documentation}
+ *
+ * @{
+ */
+
+#include <netlink-private/netlink.h>
+#include <netlink/netlink.h>
+#include <netlink/attr.h>
+#include <netlink/utils.h>
+#include <netlink/object.h>
+#include <netlink/route/rtnl.h>
+#include <netlink-private/route/link/api.h>
+#include <linux/if_tunnel.h>
+
+#define SIT_ATTR_LINK          (1 << 0)
+#define SIT_ATTR_LOCAL         (1 << 1)
+#define SIT_ATTR_REMOTE        (1 << 2)
+#define SIT_ATTR_TTL           (1 << 3)
+#define SIT_ATTR_TOS           (1 << 4)
+#define SIT_ATTR_PMTUDISC      (1 << 5)
+#define SIT_ATTR_FLAGS         (1 << 6)
+#define SIT_ATTR_PROTO         (1 << 7)
+
+struct sit_info
+{
+	uint8_t    ttl;
+	uint8_t    tos;
+	uint8_t    pmtudisc;
+	uint8_t    proto;
+	uint16_t   flags;
+	uint32_t   link;
+	uint32_t   local;
+	uint32_t   remote;
+	uint32_t   sit_mask;
+};
+
+static struct nla_policy sit_policy[IFLA_IPTUN_MAX + 1] = {
+	[IFLA_IPTUN_LINK]       = { .type = NLA_U32 },
+	[IFLA_IPTUN_LOCAL]      = { .type = NLA_U32 },
+	[IFLA_IPTUN_REMOTE]     = { .type = NLA_U32 },
+	[IFLA_IPTUN_TTL]        = { .type = NLA_U8 },
+	[IFLA_IPTUN_TOS]        = { .type = NLA_U8 },
+	[IFLA_IPTUN_PMTUDISC]   = { .type = NLA_U8 },
+	[IFLA_IPTUN_FLAGS]      = { .type = NLA_U16 },
+	[IFLA_IPTUN_PROTO]      = { .type = NLA_U8 },
+};
+
+static int sit_alloc(struct rtnl_link *link)
+{
+	struct sit_info *sit;
+
+	sit = calloc(1, sizeof(*sit));
+	if (!sit)
+		return -NLE_NOMEM;
+
+	link->l_info = sit;
+
+	return 0;
+}
+
+static int sit_parse(struct rtnl_link *link, struct nlattr *data,
+		     struct nlattr *xstats)
+{
+	struct nlattr *tb[IFLA_IPTUN_MAX + 1];
+	struct sit_info *sit;
+	int err;
+
+	NL_DBG(3, "Parsing SIT link info");
+
+	err = nla_parse_nested(tb, IFLA_IPTUN_MAX, data, sit_policy);
+	if (err < 0)
+		goto errout;
+
+	err = sit_alloc(link);
+	if (err < 0)
+		goto errout;
+
+	sit = link->l_info;
+
+	if (tb[IFLA_IPTUN_LINK]) {
+		sit->link = nla_get_u32(tb[IFLA_IPTUN_LINK]);
+		sit->sit_mask |= SIT_ATTR_LINK;
+	}
+
+	if (tb[IFLA_IPTUN_LOCAL]) {
+		sit->local = nla_get_u32(tb[IFLA_IPTUN_LOCAL]);
+		sit->sit_mask |= SIT_ATTR_LOCAL;
+	}
+
+	if (tb[IFLA_IPTUN_REMOTE]) {
+		sit->remote = nla_get_u32(tb[IFLA_IPTUN_REMOTE]);
+		sit->sit_mask |= SIT_ATTR_REMOTE;
+	}
+
+	if (tb[IFLA_IPTUN_TTL]) {
+		sit->ttl = nla_get_u8(tb[IFLA_IPTUN_TTL]);
+		sit->sit_mask |= SIT_ATTR_TTL;
+	}
+
+	if (tb[IFLA_IPTUN_TOS]) {
+		sit->tos = nla_get_u8(tb[IFLA_IPTUN_TOS]);
+		sit->sit_mask |= SIT_ATTR_TOS;
+	}
+
+	if (tb[IFLA_IPTUN_PMTUDISC]) {
+		sit->pmtudisc = nla_get_u8(tb[IFLA_IPTUN_PMTUDISC]);
+		sit->sit_mask |= SIT_ATTR_PMTUDISC;
+	}
+
+	if (tb[IFLA_IPTUN_FLAGS]) {
+		sit->flags = nla_get_u16(tb[IFLA_IPTUN_FLAGS]);
+		sit->sit_mask |= SIT_ATTR_FLAGS;
+	}
+
+	if (tb[IFLA_IPTUN_PROTO]) {
+		sit->proto = nla_get_u8(tb[IFLA_IPTUN_PROTO]);
+		sit->sit_mask |= SIT_ATTR_PROTO;
+	}
+
+	err = 0;
+
+ errout:
+	return err;
+}
+
+static int sit_put_attrs(struct nl_msg *msg, struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+	struct nlattr *data;
+
+	data = nla_nest_start(msg, IFLA_INFO_DATA);
+	if (!data)
+		return -NLE_MSGSIZE;
+
+	if (sit->sit_mask & SIT_ATTR_LINK)
+		NLA_PUT_U32(msg, IFLA_IPTUN_LINK, sit->link);
+
+	if (sit->sit_mask & SIT_ATTR_LOCAL)
+		NLA_PUT_U32(msg, IFLA_IPTUN_LOCAL, sit->local);
+
+	if (sit->sit_mask & SIT_ATTR_REMOTE)
+		NLA_PUT_U32(msg, IFLA_IPTUN_REMOTE, sit->remote);
+
+	if (sit->sit_mask & SIT_ATTR_TTL)
+		NLA_PUT_U8(msg, IFLA_IPTUN_TTL, sit->ttl);
+
+	if (sit->sit_mask & SIT_ATTR_TOS)
+		NLA_PUT_U8(msg, IFLA_IPTUN_TOS, sit->tos);
+
+	if (sit->sit_mask & SIT_ATTR_PMTUDISC)
+		NLA_PUT_U8(msg, IFLA_IPTUN_PMTUDISC, sit->pmtudisc);
+
+	if (sit->sit_mask & SIT_ATTR_FLAGS)
+		NLA_PUT_U16(msg, IFLA_IPTUN_FLAGS, sit->flags);
+
+	if (sit->sit_mask & SIT_ATTR_PROTO)
+		NLA_PUT_U8(msg, IFLA_IPTUN_PROTO, sit->proto);
+
+	nla_nest_end(msg, data);
+
+nla_put_failure:
+
+	return 0;
+}
+
+static void sit_free(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	free(sit);
+	link->l_info = NULL;
+}
+
+static void sit_dump_line(struct rtnl_link *link, struct nl_dump_params *p)
+{
+	nl_dump(p, "sit : %s", link->l_name);
+}
+
+static void sit_dump_details(struct rtnl_link *link, struct nl_dump_params *p)
+{
+	struct sit_info *sit = link->l_info;
+	char *name, addr[INET_ADDRSTRLEN];
+
+	if (sit->sit_mask & SIT_ATTR_LINK) {
+		nl_dump(p, "      link ");
+		name = rtnl_link_get_name(link);
+		if (name)
+			nl_dump_line(p, "%s\n", name);
+		else
+			nl_dump_line(p, "%u\n", sit->link);
+	}
+
+	if (sit->sit_mask & SIT_ATTR_LOCAL) {
+		nl_dump(p, "      local ");
+		if(inet_ntop(AF_INET, &sit->local, addr, sizeof(addr)))
+			nl_dump_line(p, "%s\n", addr);
+		else
+			nl_dump_line(p, "%#x\n", ntohs(sit->local));
+	}
+
+	if (sit->sit_mask & SIT_ATTR_REMOTE) {
+		nl_dump(p, "      remote ");
+		if(inet_ntop(AF_INET, &sit->remote, addr, sizeof(addr)))
+			nl_dump_line(p, "%s\n", addr);
+		else
+			nl_dump_line(p, "%#x\n", ntohs(sit->remote));
+	}
+
+	if (sit->sit_mask & SIT_ATTR_TTL) {
+		nl_dump(p, "      ttl ");
+		nl_dump_line(p, "%u\n", sit->ttl);
+	}
+
+	if (sit->sit_mask & SIT_ATTR_TOS) {
+		nl_dump(p, "      tos ");
+		nl_dump_line(p, "%u\n", sit->tos);
+	}
+
+	if (sit->sit_mask & SIT_ATTR_FLAGS) {
+		nl_dump(p, "      flags ");
+		nl_dump_line(p, " (%x)\n", sit->flags);
+	}
+
+	if (sit->sit_mask & SIT_ATTR_PROTO) {
+		nl_dump(p, "    proto   ");
+		nl_dump_line(p, " (%x)\n", sit->proto);
+	}
+}
+
+static int sit_clone(struct rtnl_link *dst, struct rtnl_link *src)
+{
+	struct sit_info *sit_dst, *sit_src = src->l_info;
+	int err;
+
+	dst->l_info = NULL;
+
+	err = rtnl_link_set_type(dst, "sit");
+	if (err < 0)
+		return err;
+
+	sit_dst = dst->l_info;
+
+	if (!sit_dst || !sit_src)
+		return -NLE_NOMEM;
+
+	memcpy(sit_dst, sit_src, sizeof(struct sit_info));
+
+	return 0;
+}
+
+static struct rtnl_link_info_ops sit_info_ops = {
+	.io_name                = "sit",
+	.io_alloc               = sit_alloc,
+	.io_parse               = sit_parse,
+	.io_dump = {
+		[NL_DUMP_LINE]  = sit_dump_line,
+		[NL_DUMP_DETAILS] = sit_dump_details,
+	},
+	.io_clone               = sit_clone,
+	.io_put_attrs           = sit_put_attrs,
+	.io_free                = sit_free,
+};
+
+#define IS_SIT_LINK_ASSERT(link)                                           \
+        if ((link)->l_info_ops != &sit_info_ops) {                         \
+                APPBUG("Link is not a sit link. set type \"sit\" first."); \
+                return -NLE_OPNOTSUPP;                                     \
+        }
+
+struct rtnl_link *rtnl_link_sit_alloc(void)
+{
+	struct rtnl_link *link;
+	int err;
+
+	link = rtnl_link_alloc();
+	if (!link)
+		return NULL;
+
+	err = rtnl_link_set_type(link, "sit");
+	if (err < 0) {
+		rtnl_link_put(link);
+		return NULL;
+	}
+
+	return link;
+}
+
+/**
+ * Check if link is a SIT link
+ * @arg link            Link object
+ *
+ * @return True if link is a SIT link, otherwise false is returned.
+ */
+int rtnl_link_is_sit(struct rtnl_link *link)
+{
+	return link->l_info_ops && !strcmp(link->l_info_ops->io_name, "sit");
+}
+
+/**
+ * Create a new sit tunnel device
+ * @arg sock            netlink socket
+ * @arg name            name of the tunnel device
+ *
+ * Creates a new sit tunnel device in the kernel
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_add(struct nl_sock *sk, const char *name)
+{
+	struct rtnl_link *link;
+	int err;
+
+	link = rtnl_link_sit_alloc();
+	if (!link)
+		return -NLE_NOMEM;
+
+	if(name)
+		rtnl_link_set_name(link, name);
+
+	err = rtnl_link_add(sk, link, NLM_F_CREATE);
+	rtnl_link_put(link);
+
+	return err;
+}
+
+/**
+ * Set SIT tunnel interface index
+ * @arg link            Link object
+ * @arg index           interface index
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_link(struct rtnl_link *link,  uint32_t index)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->link = index;
+	sit->sit_mask |= SIT_ATTR_LINK;
+
+	return 0;
+}
+
+/**
+ * Get SIT tunnel interface index
+ * @arg link            Link object
+ *
+ * @return interface index value
+ */
+uint32_t rtnl_link_sit_get_link(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->link;
+}
+
+/**
+ * Set SIT tunnel local address
+ * @arg link            Link object
+ * @arg addr            local address
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_local(struct rtnl_link *link, uint32_t addr)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->local = addr;
+	sit->sit_mask |= SIT_ATTR_LOCAL;
+
+	return 0;
+}
+
+/**
+ * Get SIT tunnel local address
+ * @arg link            Link object
+ *
+ * @return local address value
+ */
+uint32_t rtnl_link_sit_get_local(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->local;
+}
+
+/**
+ * Set SIT tunnel remote address
+ * @arg link            Link object
+ * @arg remote          remote address
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_remote(struct rtnl_link *link, uint32_t addr)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->remote = addr;
+	sit->sit_mask |= SIT_ATTR_REMOTE;
+
+	return 0;
+}
+
+/**
+ * Get SIT tunnel remote address
+ * @arg link            Link object
+ *
+ * @return remote address
+ */
+uint32_t rtnl_link_sit_get_remote(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->remote;
+}
+
+/**
+ * Set SIT tunnel ttl
+ * @arg link            Link object
+ * @arg ttl             tunnel ttl
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_ttl(struct rtnl_link *link, uint8_t ttl)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->ttl = ttl;
+	sit->sit_mask |= SIT_ATTR_TTL;
+
+	return 0;
+}
+
+/**
+ * Get SIT tunnel ttl
+ * @arg link            Link object
+ *
+ * @return ttl value
+ */
+uint8_t rtnl_link_sit_get_ttl(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->ttl;
+}
+
+/**
+ * Set SIT tunnel tos
+ * @arg link            Link object
+ * @arg tos             tunnel tos
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_tos(struct rtnl_link *link, uint8_t tos)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->tos = tos;
+	sit->sit_mask |= SIT_ATTR_TOS;
+
+	return 0;
+}
+
+/**
+ * Get SIT tunnel tos
+ * @arg link            Link object
+ *
+ * @return tos value
+ */
+uint8_t rtnl_link_sit_get_tos(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->tos;
+}
+
+/**
+ * Set SIT tunnel path MTU discovery
+ * @arg link            Link object
+ * @arg pmtudisc        path MTU discovery
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_pmtudisc(struct rtnl_link *link, uint8_t pmtudisc)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->pmtudisc = pmtudisc;
+	sit->sit_mask |= SIT_ATTR_PMTUDISC;
+
+	return 0;
+}
+
+/**
+ * Get SIT path MTU discovery
+ * @arg link            Link object
+ *
+ * @return pmtudisc value
+ */
+uint8_t rtnl_link_sit_get_pmtudisc(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->pmtudisc;
+}
+
+/**
+ * Set SIT tunnel flags
+ * @arg link            Link object
+ * @arg flags           tunnel flags
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_flags(struct rtnl_link *link, uint16_t flags)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->flags = flags;
+	sit->sit_mask |= SIT_ATTR_FLAGS;
+
+	return 0;
+}
+
+/**
+ * Get SIT path flags
+ * @arg link            Link object
+ *
+ * @return flags value
+ */
+uint16_t rtnl_link_sit_get_flags(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->flags;
+}
+
+/**
+ * Set SIT tunnel proto
+ * @arg link            Link object
+ * @arg proto           tunnel proto
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_sit_set_proto(struct rtnl_link *link, uint8_t proto)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	sit->proto = proto;
+	sit->sit_mask |= SIT_ATTR_PROTO;
+
+	return 0;
+}
+
+/**
+ * Get SIT proto
+ * @arg link            Link object
+ *
+ * @return proto value
+ */
+uint8_t rtnl_link_sit_get_proto(struct rtnl_link *link)
+{
+	struct sit_info *sit = link->l_info;
+
+	IS_SIT_LINK_ASSERT(link);
+
+	return sit->proto;
+}
+
+static void __init sit_init(void)
+{
+	rtnl_link_register_info(&sit_info_ops);
+}
+
+static void __exit sit_exit(void)
+{
+	rtnl_link_unregister_info(&sit_info_ops);
+}